Mark uninterpreted conversions with literals as approximate#1155

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copybara-service merged 1 commit into from
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Mark uninterpreted conversions with literals as approximate #1155

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4 changes: 3 additions & 1 deletion verifier/src/main/java/dev/cel/verifier/CelAstToZ3Translator.java
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Original file line numberDiff line numberDiff line change
Expand Up@@ -741,8 +741,10 @@ private TranslatedValue translateCall(CelExpr expr, CelAbstractSyntaxTree ast) {
typeConstraints.add(ctx.mkNot(typeSystem.isUnknown(callRes)));
typeConstraints.add(ctx.mkNot(typeSystem.isError(callRes)));

boolean isDynamic = ast.getType(exprId).map(SimpleType.DYN::equals).orElse(true);
BoolExpr isApprox = ctx.mkBool(!isDynamic);
return TranslatedValue.propagateStrict(
ctx, typeSystem, callRes, Optional.of(expr), ctx.mkTrue(), args);
ctx, typeSystem, callRes, Optional.of(expr), isApprox, args);
});
}

Expand Down
3 changes: 2 additions & 1 deletion verifier/src/main/java/dev/cel/verifier/CelZ3OperatorTranslator.java
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Original file line numberDiff line numberDiff line change
Expand Up@@ -594,7 +594,8 @@ private TranslatedValue translateEquality(
// because X == X is a tautology (or propagates errors/unknowns exactly).
if (z3Arg0.equals(z3Arg1)) {
Expr<?> finalResult = typeSystem.propagateErrorAndUnknown(equalityExpr, z3Arg0);
return TranslatedValue.create(finalResult, typeSystem, ctx.mkFalse());
return TranslatedValue.create(
finalResult, typeSystem, ctx.mkOr(arg0.isApproximate(), arg1.isApproximate()));
}

return TranslatedValue.propagateStrict(ctx, typeSystem, equalityExpr, arg0, arg1)
Expand Down
30 changes: 30 additions & 0 deletions verifier/src/main/java/dev/cel/verifier/CelZ3TypeSystem.java
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Original file line numberDiff line numberDiff line change
Expand Up@@ -26,6 +26,7 @@
import com.microsoft.z3.DatatypeSort;
import com.microsoft.z3.Expr;
import com.microsoft.z3.FPExpr;
import com.microsoft.z3.FPNum;
import com.microsoft.z3.FuncDecl;
import com.microsoft.z3.IntExpr;
import com.microsoft.z3.SeqExpr;
Expand DownExpand Up@@ -280,6 +281,35 @@ Constructor optionalCons() {
return optionalCons;
}

/**
* Checks if the given CelValue expression represents a statically known primitive constant.
*
* <p>This is useful for determining whether an uninterpreted function's result should be treated
* as an approximation. If the argument is a known constant, any resulting error is an
* approximation (e.g., parsing a literal string). If it's a variable, the error is an exact
* runtime failure.
*/
public boolean isPrimitiveConstant(Expr<?> expr) {
if (!expr.isApp()) {
return false;
}
FuncDecl<?> decl = expr.getFuncDecl();
if (decl.equals(stringCons.ConstructorDecl()) || decl.equals(bytesCons.ConstructorDecl())) {
return expr.getArgs()[0].isString();
} else if (decl.equals(intCons.ConstructorDecl())
|| decl.equals(uintCons.ConstructorDecl())
|| decl.equals(timestampCons.ConstructorDecl())
|| decl.equals(durationCons.ConstructorDecl())) {
return expr.getArgs()[0].isNumeral();
} else if (decl.equals(doubleCons.ConstructorDecl())) {
return expr.getArgs()[0] instanceof FPNum;
} else if (decl.equals(boolCons.ConstructorDecl())) {
Expr<?> inner = expr.getArgs()[0];
return inner.isTrue() || inner.isFalse();
}
return false;
}

/** Creates a CelValue containing a boolean. */
public Expr<?> mkBool(boolean val) {
return ctx.mkApp(boolCons.ConstructorDecl(), ctx.mkBool(val));
Expand Down
153 changes: 75 additions & 78 deletions verifier/src/main/java/dev/cel/verifier/axioms/TypeConversionAxioms.java
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Original file line numberDiff line numberDiff line change
Expand Up@@ -19,11 +19,13 @@
import com.google.common.collect.ImmutableList;
import com.microsoft.z3.BoolExpr;
import com.microsoft.z3.Expr;
import com.microsoft.z3.FPExpr;
import com.microsoft.z3.FuncDecl;
import com.microsoft.z3.IntExpr;
import com.microsoft.z3.Sort;
import dev.cel.checker.CelStandardDeclarations.StandardFunction;
import dev.cel.checker.CelStandardDeclarations.StandardFunction.Overload.Conversions;
import dev.cel.common.types.SimpleType;
import java.util.Optional;

/** Axiomatization for CEL's type conversion functions. */
Expand All@@ -42,14 +44,12 @@ final class TypeConversionAxioms {
return Optional.of(
typeSystem.withRuntimeError(typeSystem.wrapInt(uintVal), outOfBounds));
})
.addUnaryOverloadTranslator(
.addOverloadTranslator(
Conversions.DOUBLE_TO_INT64.celOverloadDecl(),
createUninterpretedConversion(Conversions.DOUBLE_TO_INT64),
/* isApproximated= */ true)
.addUnaryOverloadTranslator(
createUninterpretedConversion(Conversions.DOUBLE_TO_INT64))
.addOverloadTranslator(
Conversions.STRING_TO_INT64.celOverloadDecl(),
createUninterpretedConversion(Conversions.STRING_TO_INT64),
/* isApproximated= */ true)
createUninterpretedConversion(Conversions.STRING_TO_INT64))
.addUnaryOverloadTranslator(
Conversions.TIMESTAMP_TO_INT64.celOverloadDecl(),
(ctx, typeSystem, sink, arg) ->
Expand All@@ -69,79 +69,66 @@ final class TypeConversionAxioms {
return Optional.of(
typeSystem.withRuntimeError(typeSystem.wrapUint(intVal), outOfBounds));
})
.addUnaryOverloadTranslator(
.addOverloadTranslator(
Conversions.DOUBLE_TO_UINT64.celOverloadDecl(),
createUninterpretedConversion(Conversions.DOUBLE_TO_UINT64),
/* isApproximated= */ true)
.addUnaryOverloadTranslator(
createUninterpretedConversion(Conversions.DOUBLE_TO_UINT64))
.addOverloadTranslator(
Conversions.STRING_TO_UINT64.celOverloadDecl(),
createUninterpretedConversion(Conversions.STRING_TO_UINT64),
/* isApproximated= */ true)
createUninterpretedConversion(Conversions.STRING_TO_UINT64))
.build();

private static final CelZ3FunctionAxiom DOUBLE_AXIOM =
CelZ3FunctionAxiom.newBuilder(StandardFunction.DOUBLE.functionDecl())
.addUnaryOverloadTranslator(
Conversions.DOUBLE_TO_DOUBLE.celOverloadDecl(),
(ctx, typeSystem, sink, arg) -> Optional.of(arg))
.addUnaryOverloadTranslator(
.addOverloadTranslator(
Conversions.INT64_TO_DOUBLE.celOverloadDecl(),
createUninterpretedConversion(Conversions.INT64_TO_DOUBLE),
/* isApproximated= */ true)
.addUnaryOverloadTranslator(
createUninterpretedConversion(Conversions.INT64_TO_DOUBLE))
.addOverloadTranslator(
Conversions.UINT64_TO_DOUBLE.celOverloadDecl(),
createUninterpretedConversion(Conversions.UINT64_TO_DOUBLE),
/* isApproximated= */ true)
.addUnaryOverloadTranslator(
createUninterpretedConversion(Conversions.UINT64_TO_DOUBLE))
.addOverloadTranslator(
Conversions.STRING_TO_DOUBLE.celOverloadDecl(),
createUninterpretedConversion(Conversions.STRING_TO_DOUBLE),
/* isApproximated= */ true)
createUninterpretedConversion(Conversions.STRING_TO_DOUBLE))
.build();

private static final CelZ3FunctionAxiom STRING_AXIOM =
CelZ3FunctionAxiom.newBuilder(StandardFunction.STRING.functionDecl())
.addUnaryOverloadTranslator(
Conversions.STRING_TO_STRING.celOverloadDecl(),
(ctx, typeSystem, sink, arg) -> Optional.of(arg))
.addUnaryOverloadTranslator(
.addOverloadTranslator(
Conversions.INT64_TO_STRING.celOverloadDecl(),
createUninterpretedConversion(Conversions.INT64_TO_STRING),
/* isApproximated= */ true)
.addUnaryOverloadTranslator(
createUninterpretedConversion(Conversions.INT64_TO_STRING))
.addOverloadTranslator(
Conversions.UINT64_TO_STRING.celOverloadDecl(),
createUninterpretedConversion(Conversions.UINT64_TO_STRING),
/* isApproximated= */ true)
.addUnaryOverloadTranslator(
createUninterpretedConversion(Conversions.UINT64_TO_STRING))
.addOverloadTranslator(
Conversions.DOUBLE_TO_STRING.celOverloadDecl(),
createUninterpretedConversion(Conversions.DOUBLE_TO_STRING),
/* isApproximated= */ true)
.addUnaryOverloadTranslator(
createUninterpretedConversion(Conversions.DOUBLE_TO_STRING))
.addOverloadTranslator(
Conversions.BOOL_TO_STRING.celOverloadDecl(),
createUninterpretedConversion(Conversions.BOOL_TO_STRING),
/* isApproximated= */ true)
.addUnaryOverloadTranslator(
createUninterpretedConversion(Conversions.BOOL_TO_STRING))
.addOverloadTranslator(
Conversions.BYTES_TO_STRING.celOverloadDecl(),
createUninterpretedConversion(Conversions.BYTES_TO_STRING),
/* isApproximated= */ true)
.addUnaryOverloadTranslator(
createUninterpretedConversion(Conversions.BYTES_TO_STRING))
.addOverloadTranslator(
Conversions.TIMESTAMP_TO_STRING.celOverloadDecl(),
createUninterpretedConversion(Conversions.TIMESTAMP_TO_STRING),
/* isApproximated= */ true)
.addUnaryOverloadTranslator(
createUninterpretedConversion(Conversions.TIMESTAMP_TO_STRING))
.addOverloadTranslator(
Conversions.DURATION_TO_STRING.celOverloadDecl(),
createUninterpretedConversion(Conversions.DURATION_TO_STRING),
/* isApproximated= */ true)
createUninterpretedConversion(Conversions.DURATION_TO_STRING))
.build();

private static final CelZ3FunctionAxiom BYTES_AXIOM =
CelZ3FunctionAxiom.newBuilder(StandardFunction.BYTES.functionDecl())
.addUnaryOverloadTranslator(
Conversions.BYTES_TO_BYTES.celOverloadDecl(),
(ctx, typeSystem, sink, arg) -> Optional.of(arg))
.addUnaryOverloadTranslator(
.addOverloadTranslator(
Conversions.STRING_TO_BYTES.celOverloadDecl(),
createUninterpretedConversion(Conversions.STRING_TO_BYTES),
/* isApproximated= */ true)
createUninterpretedConversion(Conversions.STRING_TO_BYTES))
.build();

private static final CelZ3FunctionAxiom DYN_AXIOM =
Expand All@@ -156,21 +143,19 @@ final class TypeConversionAxioms {
.addUnaryOverloadTranslator(
Conversions.DURATION_TO_DURATION.celOverloadDecl(),
(ctx, typeSystem, sink, arg) -> Optional.of(arg))
.addUnaryOverloadTranslator(
.addOverloadTranslator(
Conversions.STRING_TO_DURATION.celOverloadDecl(),
createUninterpretedConversion(Conversions.STRING_TO_DURATION),
/* isApproximated= */ true)
createUninterpretedConversion(Conversions.STRING_TO_DURATION))
.build();

private static final CelZ3FunctionAxiom TIMESTAMP_AXIOM =
CelZ3FunctionAxiom.newBuilder(StandardFunction.TIMESTAMP.functionDecl())
.addUnaryOverloadTranslator(
Conversions.TIMESTAMP_TO_TIMESTAMP.celOverloadDecl(),
(ctx, typeSystem, sink, arg) -> Optional.of(arg))
.addUnaryOverloadTranslator(
.addOverloadTranslator(
Conversions.STRING_TO_TIMESTAMP.celOverloadDecl(),
createUninterpretedConversion(Conversions.STRING_TO_TIMESTAMP),
/* isApproximated= */ true)
createUninterpretedConversion(Conversions.STRING_TO_TIMESTAMP))
.addUnaryOverloadTranslator(
Conversions.INT64_TO_TIMESTAMP.celOverloadDecl(),
(ctx, typeSystem, sink, arg) -> {
Expand All@@ -186,10 +171,9 @@ final class TypeConversionAxioms {
.addUnaryOverloadTranslator(
Conversions.BOOL_TO_BOOL.celOverloadDecl(),
(ctx, typeSystem, sink, arg) -> Optional.of(arg))
.addUnaryOverloadTranslator(
.addOverloadTranslator(
Conversions.STRING_TO_BOOL.celOverloadDecl(),
createUninterpretedConversion(Conversions.STRING_TO_BOOL),
/* isApproximated= */ true)
createUninterpretedConversion(Conversions.STRING_TO_BOOL))
.build();

static final ImmutableList<CelZ3FunctionAxiom> ALL_AXIOMS =
Expand All@@ -204,64 +188,77 @@ final class TypeConversionAxioms {
TIMESTAMP_AXIOM,
BOOL_AXIOM);

private static CelZ3FunctionAxiom.UnaryTranslator createUninterpretedConversion(
Conversions conversion) {
return (ctx, typeSystem, sink, arg) -> {
private static CelZ3OverloadTranslator createUninterpretedConversion(Conversions conversion) {
return (ctx, typeSystem, sink, unwrappedArgs, argApproximations) -> {
Expr<?> arg = unwrappedArgs.get(0);
BoolExpr baseApprox = argApproximations.get(0);

FuncDecl<?> funcDecl =
typeSystem.internFuncDecl(
conversion.celOverloadDecl().overloadId(),
new Sort[] {typeSystem.celValueSort()},
typeSystem.celValueSort());
Expr<?> res = ctx.mkApp(funcDecl, arg);

BoolExpr isValid;
switch (conversion.celOverloadDecl().resultType().kind()) {
case INT:
isValid =
ctx.mkAnd(
sink.accept(ctx.mkOr(typeSystem.isInt(res), typeSystem.isError(res)));
sink.accept(
ctx.mkImplies(
typeSystem.isInt(res),
ctx.mkNot(typeSystem.checkIntOverflow(typeSystem.getInt(res))));
ctx.mkNot(typeSystem.checkIntOverflow(typeSystem.getInt(res)))));
break;
case TIMESTAMP:
isValid =
ctx.mkAnd(
sink.accept(ctx.mkOr(typeSystem.isTimestamp(res), typeSystem.isError(res)));
sink.accept(
ctx.mkImplies(
typeSystem.isTimestamp(res),
ctx.mkNot(typeSystem.checkTimestampOverflow(typeSystem.getTimestamp(res))));
ctx.mkNot(typeSystem.checkTimestampOverflow(typeSystem.getTimestamp(res)))));
break;
case DURATION:
isValid =
ctx.mkAnd(
sink.accept(ctx.mkOr(typeSystem.isDuration(res), typeSystem.isError(res)));
sink.accept(
ctx.mkImplies(
typeSystem.isDuration(res),
ctx.mkNot(typeSystem.checkDurationOverflow(typeSystem.getDuration(res))));
ctx.mkNot(typeSystem.checkDurationOverflow(typeSystem.getDuration(res)))));
break;
case UINT:
isValid =
ctx.mkAnd(
sink.accept(ctx.mkOr(typeSystem.isUint(res), typeSystem.isError(res)));
sink.accept(
ctx.mkImplies(
typeSystem.isUint(res),
ctx.mkNot(typeSystem.checkUintOverflow(typeSystem.getUint(res))));
ctx.mkNot(typeSystem.checkUintOverflow(typeSystem.getUint(res)))));
break;
case DOUBLE:
isValid =
ctx.mkAnd(
typeSystem.isDouble(res), ctx.mkNot(ctx.mkFPIsNaN(typeSystem.getDouble(res))));
sink.accept(ctx.mkOr(typeSystem.isDouble(res), typeSystem.isError(res)));
sink.accept(
ctx.mkImplies(
typeSystem.isDouble(res),
ctx.mkNot(ctx.mkFPIsNaN((FPExpr) typeSystem.getDouble(res)))));
break;
case STRING:
isValid = typeSystem.isString(res);
sink.accept(ctx.mkOr(typeSystem.isString(res), typeSystem.isError(res)));
break;
case BYTES:
isValid = typeSystem.isBytes(res);
sink.accept(ctx.mkOr(typeSystem.isBytes(res), typeSystem.isError(res)));
break;
case BOOL:
isValid = typeSystem.isBool(res);
sink.accept(ctx.mkOr(typeSystem.isBool(res), typeSystem.isError(res)));
break;
default:
throw new IllegalArgumentException(
"Unsupported uninterpreted conversion result type: "
+ conversion.celOverloadDecl().resultType());
}

sink.accept(ctx.mkOr(isValid, typeSystem.isError(res)));
return Optional.of(res);
boolean isArgConstant = typeSystem.isPrimitiveConstant(arg);
boolean isStringParseConversion =
conversion.celOverloadDecl().parameterTypes().get(0).equals(SimpleType.STRING);

BoolExpr finalApprox =
(!isArgConstant && isStringParseConversion) ? baseApprox : ctx.mkTrue();

return Optional.of(CelZ3OverloadResult.create(res, finalApprox));
};
}

Expand Down
17 changes: 9 additions & 8 deletions verifier/src/test/java/dev/cel/verifier/CelVerifierZ3ImplTest.java
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Original file line numberDiff line numberDiff line change
Expand Up@@ -154,8 +154,6 @@ private enum IsSatisfiableTestCase {
NULL_SATISFIABLE("unknown_var == null"),
DYNAMIC_VAR_NUMERIC_EQUALITY("dyn_var == 1 && dyn_var == 1.0"),
DYNAMIC_VAR_NOT_IN_LIST("dyn_var == 1.5 && !(dyn_var in dyn_list) && size(dyn_list) > 5"),
TIMESTAMP_EQUALITY_TAUTOLOGY(
"timestamp('2023-01-01T00:00:00Z') == timestamp('2023-01-01T00:00:00Z')"),
CROSS_NUMERIC_EQUALITY_INT_DYN_EXACT("1 == request"),
MACRO_LIMIT("dyn_list.all(x, x == 1)"),
STRUCT_FIELD_MISSING_APPROXIMATE_SATISFIABLE("dyn_var.unknown_field"),
Expand DownExpand Up@@ -1353,12 +1351,10 @@ private enum IsAlwaysTrueViolationTestCase {
"duration(string_var) == duration(string_var)",
"Condition is not always true\\.",
"Counterexample input:"),
// TODO: Implement RFC 3339 spec in conversion
TIMESTAMP_STRING_CONVERSION_VALID(
"timestamp('2023-01-01T00:00:00Z') == timestamp('2023-01-01T00:00:00Z')",
"Condition is not always true\\."),
DURATION_STRING_CONVERSION_VALID(
"duration('100s') == duration('100s')", "Condition is not always true\\."),
UNINTERPRETED_CONVERSION_CAN_ERROR_BOOL_FROM_STRING(
"bool(string_var) == bool(string_var)",
"Condition is not always true\\.",
"Counterexample input:"),
;

final String expr;
Expand All@@ -1384,6 +1380,11 @@ public void isAlwaysTrue_violation_returnsFalse(
}

private enum IsInconclusiveTestCase {
// TODO: Implement RFC 3339 spec in conversion
TIMESTAMP_STRING_CONVERSION_VALID(
"timestamp('2023-01-01T00:00:00Z') == timestamp('2023-01-01T00:00:00Z')"),
DURATION_STRING_CONVERSION_VALID("duration('100s') == duration('100s')"),
BOOL_STRING_UNINTERPRETED("bool('true') == true"),
TIMESTAMP_ADD_DURATION_OVERFLOW("timestamp(253402300799) + duration('100s') > timestamp(0)"),
DYNAMIC_EQUALITY_TIMESTAMP_INT_COLLISION(
"type(dyn_var) == int && dyn_var == 0 ? dyn_var != timestamp('1970-01-01T00:00:00Z') :"
Expand Down
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, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
 blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

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Mark uninterpreted conversions with literals as approximate#1155

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 Merged

copybara-service
merged 1 commit into

from

Aug 1, 2026
 Merged


Mark uninterpreted conversions with literals as approximate
#1155
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4 changes: 3 additions & 1 deletion
verifier/src/main/java/dev/cel/verifier/CelAstToZ3Translator.java

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Original file line numberDiff line numberDiff line change
Expand Up@@ -741,8 +741,10 @@ private TranslatedValue translateCall(CelExpr expr, CelAbstractSyntaxTree ast) {
 typeConstraints.add(ctx.mkNot(typeSystem.isUnknown(callRes)));
 typeConstraints.add(ctx.mkNot(typeSystem.isError(callRes)));

 boolean isDynamic = ast.getType(exprId).map(SimpleType.DYN::equals).orElse(true);
 BoolExpr isApprox = ctx.mkBool(!isDynamic);
 return TranslatedValue.propagateStrict(
 ctx, typeSystem, callRes, Optional.of(expr), ctx.mkTrue(), args);
 ctx, typeSystem, callRes, Optional.of(expr), isApprox, args);
 });
 }

Expand Down

3 changes: 2 additions & 1 deletion
verifier/src/main/java/dev/cel/verifier/CelZ3OperatorTranslator.java

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Original file line numberDiff line numberDiff line change
Expand Up@@ -594,7 +594,8 @@ private TranslatedValue translateEquality(
 // because X == X is a tautology (or propagates errors/unknowns exactly).
 if (z3Arg0.equals(z3Arg1)) {
 Expr<?> finalResult = typeSystem.propagateErrorAndUnknown(equalityExpr, z3Arg0);
 return TranslatedValue.create(finalResult, typeSystem, ctx.mkFalse());
 return TranslatedValue.create(
 finalResult, typeSystem, ctx.mkOr(arg0.isApproximate(), arg1.isApproximate()));
 }

 return TranslatedValue.propagateStrict(ctx, typeSystem, equalityExpr, arg0, arg1)
Expand Down

30 changes: 30 additions & 0 deletions
verifier/src/main/java/dev/cel/verifier/CelZ3TypeSystem.java

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Original file line numberDiff line numberDiff line change
Expand Up@@ -26,6 +26,7 @@
import com.microsoft.z3.DatatypeSort;
import com.microsoft.z3.Expr;
import com.microsoft.z3.FPExpr;
import com.microsoft.z3.FPNum;
import com.microsoft.z3.FuncDecl;
import com.microsoft.z3.IntExpr;
import com.microsoft.z3.SeqExpr;
Expand DownExpand Up@@ -280,6 +281,35 @@ Constructor optionalCons() {
 return optionalCons;
 }

 /**
 * Checks if the given CelValue expression represents a statically known primitive constant.
 *
 * <p>This is useful for determining whether an uninterpreted function's result should be treated
 * as an approximation. If the argument is a known constant, any resulting error is an
 * approximation (e.g., parsing a literal string). If it's a variable, the error is an exact
 * runtime failure.
 */
 public boolean isPrimitiveConstant(Expr<?> expr) {
 if (!expr.isApp()) {
 return false;
 }
 FuncDecl<?> decl = expr.getFuncDecl();
 if (decl.equals(stringCons.ConstructorDecl()) || decl.equals(bytesCons.ConstructorDecl())) {
 return expr.getArgs()[0].isString();
 } else if (decl.equals(intCons.ConstructorDecl())
 || decl.equals(uintCons.ConstructorDecl())
 || decl.equals(timestampCons.ConstructorDecl())
 || decl.equals(durationCons.ConstructorDecl())) {
 return expr.getArgs()[0].isNumeral();
 } else if (decl.equals(doubleCons.ConstructorDecl())) {
 return expr.getArgs()[0] instanceof FPNum;
 } else if (decl.equals(boolCons.ConstructorDecl())) {
 Expr<?> inner = expr.getArgs()[0];
 return inner.isTrue() || inner.isFalse();
 }
 return false;
 }

 /** Creates a CelValue containing a boolean. */
 public Expr<?> mkBool(boolean val) {
 return ctx.mkApp(boolCons.ConstructorDecl(), ctx.mkBool(val));
Expand Down

153 changes: 75 additions & 78 deletions
verifier/src/main/java/dev/cel/verifier/axioms/TypeConversionAxioms.java

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Original file line numberDiff line numberDiff line change
Expand Up@@ -19,11 +19,13 @@
import com.google.common.collect.ImmutableList;
import com.microsoft.z3.BoolExpr;
import com.microsoft.z3.Expr;
import com.microsoft.z3.FPExpr;
import com.microsoft.z3.FuncDecl;
import com.microsoft.z3.IntExpr;
import com.microsoft.z3.Sort;
import dev.cel.checker.CelStandardDeclarations.StandardFunction;
import dev.cel.checker.CelStandardDeclarations.StandardFunction.Overload.Conversions;
import dev.cel.common.types.SimpleType;
import java.util.Optional;

/** Axiomatization for CEL's type conversion functions. */
Expand All@@ -42,14 +44,12 @@ final class TypeConversionAxioms {
 return Optional.of(
 typeSystem.withRuntimeError(typeSystem.wrapInt(uintVal), outOfBounds));
 })
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.DOUBLE_TO_INT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DOUBLE_TO_INT64),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.DOUBLE_TO_INT64))
 .addOverloadTranslator(
 Conversions.STRING_TO_INT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_INT64),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_INT64))
 .addUnaryOverloadTranslator(
 Conversions.TIMESTAMP_TO_INT64.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) ->
Expand All@@ -69,79 +69,66 @@ final class TypeConversionAxioms {
 return Optional.of(
 typeSystem.withRuntimeError(typeSystem.wrapUint(intVal), outOfBounds));
 })
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.DOUBLE_TO_UINT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DOUBLE_TO_UINT64),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.DOUBLE_TO_UINT64))
 .addOverloadTranslator(
 Conversions.STRING_TO_UINT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_UINT64),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_UINT64))
 .build();

 private static final CelZ3FunctionAxiom DOUBLE_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.DOUBLE.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.DOUBLE_TO_DOUBLE.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.INT64_TO_DOUBLE.celOverloadDecl(),
 createUninterpretedConversion(Conversions.INT64_TO_DOUBLE),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.INT64_TO_DOUBLE))
 .addOverloadTranslator(
 Conversions.UINT64_TO_DOUBLE.celOverloadDecl(),
 createUninterpretedConversion(Conversions.UINT64_TO_DOUBLE),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.UINT64_TO_DOUBLE))
 .addOverloadTranslator(
 Conversions.STRING_TO_DOUBLE.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_DOUBLE),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_DOUBLE))
 .build();

 private static final CelZ3FunctionAxiom STRING_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.STRING.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.STRING_TO_STRING.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.INT64_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.INT64_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.INT64_TO_STRING))
 .addOverloadTranslator(
 Conversions.UINT64_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.UINT64_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.UINT64_TO_STRING))
 .addOverloadTranslator(
 Conversions.DOUBLE_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DOUBLE_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.DOUBLE_TO_STRING))
 .addOverloadTranslator(
 Conversions.BOOL_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.BOOL_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.BOOL_TO_STRING))
 .addOverloadTranslator(
 Conversions.BYTES_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.BYTES_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.BYTES_TO_STRING))
 .addOverloadTranslator(
 Conversions.TIMESTAMP_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.TIMESTAMP_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.TIMESTAMP_TO_STRING))
 .addOverloadTranslator(
 Conversions.DURATION_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DURATION_TO_STRING),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.DURATION_TO_STRING))
 .build();

 private static final CelZ3FunctionAxiom BYTES_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.BYTES.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.BYTES_TO_BYTES.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_BYTES.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_BYTES),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_BYTES))
 .build();

 private static final CelZ3FunctionAxiom DYN_AXIOM =
Expand All@@ -156,21 +143,19 @@ final class TypeConversionAxioms {
 .addUnaryOverloadTranslator(
 Conversions.DURATION_TO_DURATION.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_DURATION.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_DURATION),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_DURATION))
 .build();

 private static final CelZ3FunctionAxiom TIMESTAMP_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.TIMESTAMP.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.TIMESTAMP_TO_TIMESTAMP.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_TIMESTAMP.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_TIMESTAMP),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_TIMESTAMP))
 .addUnaryOverloadTranslator(
 Conversions.INT64_TO_TIMESTAMP.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> {
Expand All@@ -186,10 +171,9 @@ final class TypeConversionAxioms {
 .addUnaryOverloadTranslator(
 Conversions.BOOL_TO_BOOL.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_BOOL.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_BOOL),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_BOOL))
 .build();

 static final ImmutableList<CelZ3FunctionAxiom> ALL_AXIOMS =
Expand All@@ -204,64 +188,77 @@ final class TypeConversionAxioms {
 TIMESTAMP_AXIOM,
 BOOL_AXIOM);

 private static CelZ3FunctionAxiom.UnaryTranslator createUninterpretedConversion(
 Conversions conversion) {
 return (ctx, typeSystem, sink, arg) -> {
 private static CelZ3OverloadTranslator createUninterpretedConversion(Conversions conversion) {
 return (ctx, typeSystem, sink, unwrappedArgs, argApproximations) -> {
 Expr<?> arg = unwrappedArgs.get(0);
 BoolExpr baseApprox = argApproximations.get(0);

 FuncDecl<?> funcDecl =
 typeSystem.internFuncDecl(
 conversion.celOverloadDecl().overloadId(),
 new Sort[] {typeSystem.celValueSort()},
 typeSystem.celValueSort());
 Expr<?> res = ctx.mkApp(funcDecl, arg);

 BoolExpr isValid;
 switch (conversion.celOverloadDecl().resultType().kind()) {
 case INT:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isInt(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isInt(res),
 ctx.mkNot(typeSystem.checkIntOverflow(typeSystem.getInt(res))));
 ctx.mkNot(typeSystem.checkIntOverflow(typeSystem.getInt(res)))));
 break;
 case TIMESTAMP:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isTimestamp(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isTimestamp(res),
 ctx.mkNot(typeSystem.checkTimestampOverflow(typeSystem.getTimestamp(res))));
 ctx.mkNot(typeSystem.checkTimestampOverflow(typeSystem.getTimestamp(res)))));
 break;
 case DURATION:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isDuration(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isDuration(res),
 ctx.mkNot(typeSystem.checkDurationOverflow(typeSystem.getDuration(res))));
 ctx.mkNot(typeSystem.checkDurationOverflow(typeSystem.getDuration(res)))));
 break;
 case UINT:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isUint(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isUint(res),
 ctx.mkNot(typeSystem.checkUintOverflow(typeSystem.getUint(res))));
 ctx.mkNot(typeSystem.checkUintOverflow(typeSystem.getUint(res)))));
 break;
 case DOUBLE:
 isValid =
 ctx.mkAnd(
 typeSystem.isDouble(res), ctx.mkNot(ctx.mkFPIsNaN(typeSystem.getDouble(res))));
 sink.accept(ctx.mkOr(typeSystem.isDouble(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isDouble(res),
 ctx.mkNot(ctx.mkFPIsNaN((FPExpr) typeSystem.getDouble(res)))));
 break;
 case STRING:
isValid = typeSystem.isString(res);
sink.accept(ctx.mkOr(typeSystem.isString(res), typeSystem.isError(res)));
 break;
 case BYTES:
isValid = typeSystem.isBytes(res);
sink.accept(ctx.mkOr(typeSystem.isBytes(res), typeSystem.isError(res)));
 break;
 case BOOL:
isValid = typeSystem.isBool(res);
sink.accept(ctx.mkOr(typeSystem.isBool(res), typeSystem.isError(res)));
 break;
 default:
 throw new IllegalArgumentException(
 "Unsupported uninterpreted conversion result type: "
 + conversion.celOverloadDecl().resultType());
 }

 sink.accept(ctx.mkOr(isValid, typeSystem.isError(res)));
 return Optional.of(res);
 boolean isArgConstant = typeSystem.isPrimitiveConstant(arg);
 boolean isStringParseConversion =
 conversion.celOverloadDecl().parameterTypes().get(0).equals(SimpleType.STRING);

 BoolExpr finalApprox =
 (!isArgConstant && isStringParseConversion) ? baseApprox : ctx.mkTrue();

 return Optional.of(CelZ3OverloadResult.create(res, finalApprox));
 };
 }

Expand Down

17 changes: 9 additions & 8 deletions
verifier/src/test/java/dev/cel/verifier/CelVerifierZ3ImplTest.java

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Original file line numberDiff line numberDiff line change
Expand Up@@ -154,8 +154,6 @@ private enum IsSatisfiableTestCase {
 NULL_SATISFIABLE("unknown_var == null"),
 DYNAMIC_VAR_NUMERIC_EQUALITY("dyn_var == 1 && dyn_var == 1.0"),
 DYNAMIC_VAR_NOT_IN_LIST("dyn_var == 1.5 && !(dyn_var in dyn_list) && size(dyn_list) > 5"),
 TIMESTAMP_EQUALITY_TAUTOLOGY(
 "timestamp('2023-01-01T00:00:00Z') == timestamp('2023-01-01T00:00:00Z')"),
 CROSS_NUMERIC_EQUALITY_INT_DYN_EXACT("1 == request"),
 MACRO_LIMIT("dyn_list.all(x, x == 1)"),
 STRUCT_FIELD_MISSING_APPROXIMATE_SATISFIABLE("dyn_var.unknown_field"),
Expand DownExpand Up@@ -1353,12 +1351,10 @@ private enum IsAlwaysTrueViolationTestCase {
 "duration(string_var) == duration(string_var)",
 "Condition is not always true\\.",
 "Counterexample input:"),
 // TODO: Implement RFC 3339 spec in conversion
 TIMESTAMP_STRING_CONVERSION_VALID(
 "timestamp('2023-01-01T00:00:00Z') == timestamp('2023-01-01T00:00:00Z')",
 "Condition is not always true\\."),
 DURATION_STRING_CONVERSION_VALID(
 "duration('100s') == duration('100s')", "Condition is not always true\\."),
 UNINTERPRETED_CONVERSION_CAN_ERROR_BOOL_FROM_STRING(
 "bool(string_var) == bool(string_var)",
 "Condition is not always true\\.",
 "Counterexample input:"),
 ;

 final String expr;
Expand All@@ -1384,6 +1380,11 @@ public void isAlwaysTrue_violation_returnsFalse(
 }

 private enum IsInconclusiveTestCase {
 // TODO: Implement RFC 3339 spec in conversion
 TIMESTAMP_STRING_CONVERSION_VALID(
 "timestamp('2023-01-01T00:00:00Z') == timestamp('2023-01-01T00:00:00Z')"),
 DURATION_STRING_CONVERSION_VALID("duration('100s') == duration('100s')"),
 BOOL_STRING_UNINTERPRETED("bool('true') == true"),
 TIMESTAMP_ADD_DURATION_OVERFLOW("timestamp(253402300799) + duration('100s') > timestamp(0)"),
 DYNAMIC_EQUALITY_TIMESTAMP_INT_COLLISION(
 "type(dyn_var) == int && dyn_var == 0 ? dyn_var != timestamp('1970-01-01T00:00:00Z') :"
Expand Down
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injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
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 Merged

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Aug 1, 2026
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Mark uninterpreted conversions with literals as approximate
#1155
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4 changes: 3 additions & 1 deletion
verifier/src/main/java/dev/cel/verifier/CelAstToZ3Translator.java

View file


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Original file line numberDiff line numberDiff line change
Expand Up@@ -741,8 +741,10 @@ private TranslatedValue translateCall(CelExpr expr, CelAbstractSyntaxTree ast) {
 typeConstraints.add(ctx.mkNot(typeSystem.isUnknown(callRes)));
 typeConstraints.add(ctx.mkNot(typeSystem.isError(callRes)));

 boolean isDynamic = ast.getType(exprId).map(SimpleType.DYN::equals).orElse(true);
 BoolExpr isApprox = ctx.mkBool(!isDynamic);
 return TranslatedValue.propagateStrict(
 ctx, typeSystem, callRes, Optional.of(expr), ctx.mkTrue(), args);
 ctx, typeSystem, callRes, Optional.of(expr), isApprox, args);
 });
 }

Expand Down

3 changes: 2 additions & 1 deletion
verifier/src/main/java/dev/cel/verifier/CelZ3OperatorTranslator.java

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Original file line numberDiff line numberDiff line change
Expand Up@@ -594,7 +594,8 @@ private TranslatedValue translateEquality(
 // because X == X is a tautology (or propagates errors/unknowns exactly).
 if (z3Arg0.equals(z3Arg1)) {
 Expr<?> finalResult = typeSystem.propagateErrorAndUnknown(equalityExpr, z3Arg0);
 return TranslatedValue.create(finalResult, typeSystem, ctx.mkFalse());
 return TranslatedValue.create(
 finalResult, typeSystem, ctx.mkOr(arg0.isApproximate(), arg1.isApproximate()));
 }

 return TranslatedValue.propagateStrict(ctx, typeSystem, equalityExpr, arg0, arg1)
Expand Down

30 changes: 30 additions & 0 deletions
verifier/src/main/java/dev/cel/verifier/CelZ3TypeSystem.java

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Original file line numberDiff line numberDiff line change
Expand Up@@ -26,6 +26,7 @@
import com.microsoft.z3.DatatypeSort;
import com.microsoft.z3.Expr;
import com.microsoft.z3.FPExpr;
import com.microsoft.z3.FPNum;
import com.microsoft.z3.FuncDecl;
import com.microsoft.z3.IntExpr;
import com.microsoft.z3.SeqExpr;
Expand DownExpand Up@@ -280,6 +281,35 @@ Constructor optionalCons() {
 return optionalCons;
 }

 /**
 * Checks if the given CelValue expression represents a statically known primitive constant.
 *
 * <p>This is useful for determining whether an uninterpreted function's result should be treated
 * as an approximation. If the argument is a known constant, any resulting error is an
 * approximation (e.g., parsing a literal string). If it's a variable, the error is an exact
 * runtime failure.
 */
 public boolean isPrimitiveConstant(Expr<?> expr) {
 if (!expr.isApp()) {
 return false;
 }
 FuncDecl<?> decl = expr.getFuncDecl();
 if (decl.equals(stringCons.ConstructorDecl()) || decl.equals(bytesCons.ConstructorDecl())) {
 return expr.getArgs()[0].isString();
 } else if (decl.equals(intCons.ConstructorDecl())
 || decl.equals(uintCons.ConstructorDecl())
 || decl.equals(timestampCons.ConstructorDecl())
 || decl.equals(durationCons.ConstructorDecl())) {
 return expr.getArgs()[0].isNumeral();
 } else if (decl.equals(doubleCons.ConstructorDecl())) {
 return expr.getArgs()[0] instanceof FPNum;
 } else if (decl.equals(boolCons.ConstructorDecl())) {
 Expr<?> inner = expr.getArgs()[0];
 return inner.isTrue() || inner.isFalse();
 }
 return false;
 }

 /** Creates a CelValue containing a boolean. */
 public Expr<?> mkBool(boolean val) {
 return ctx.mkApp(boolCons.ConstructorDecl(), ctx.mkBool(val));
Expand Down

153 changes: 75 additions & 78 deletions
verifier/src/main/java/dev/cel/verifier/axioms/TypeConversionAxioms.java

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Original file line numberDiff line numberDiff line change
Expand Up@@ -19,11 +19,13 @@
import com.google.common.collect.ImmutableList;
import com.microsoft.z3.BoolExpr;
import com.microsoft.z3.Expr;
import com.microsoft.z3.FPExpr;
import com.microsoft.z3.FuncDecl;
import com.microsoft.z3.IntExpr;
import com.microsoft.z3.Sort;
import dev.cel.checker.CelStandardDeclarations.StandardFunction;
import dev.cel.checker.CelStandardDeclarations.StandardFunction.Overload.Conversions;
import dev.cel.common.types.SimpleType;
import java.util.Optional;

/** Axiomatization for CEL's type conversion functions. */
Expand All@@ -42,14 +44,12 @@ final class TypeConversionAxioms {
 return Optional.of(
 typeSystem.withRuntimeError(typeSystem.wrapInt(uintVal), outOfBounds));
 })
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.DOUBLE_TO_INT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DOUBLE_TO_INT64),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.DOUBLE_TO_INT64))
 .addOverloadTranslator(
 Conversions.STRING_TO_INT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_INT64),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_INT64))
 .addUnaryOverloadTranslator(
 Conversions.TIMESTAMP_TO_INT64.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) ->
Expand All@@ -69,79 +69,66 @@ final class TypeConversionAxioms {
 return Optional.of(
 typeSystem.withRuntimeError(typeSystem.wrapUint(intVal), outOfBounds));
 })
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.DOUBLE_TO_UINT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DOUBLE_TO_UINT64),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.DOUBLE_TO_UINT64))
 .addOverloadTranslator(
 Conversions.STRING_TO_UINT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_UINT64),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_UINT64))
 .build();

 private static final CelZ3FunctionAxiom DOUBLE_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.DOUBLE.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.DOUBLE_TO_DOUBLE.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.INT64_TO_DOUBLE.celOverloadDecl(),
 createUninterpretedConversion(Conversions.INT64_TO_DOUBLE),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.INT64_TO_DOUBLE))
 .addOverloadTranslator(
 Conversions.UINT64_TO_DOUBLE.celOverloadDecl(),
 createUninterpretedConversion(Conversions.UINT64_TO_DOUBLE),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.UINT64_TO_DOUBLE))
 .addOverloadTranslator(
 Conversions.STRING_TO_DOUBLE.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_DOUBLE),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_DOUBLE))
 .build();

 private static final CelZ3FunctionAxiom STRING_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.STRING.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.STRING_TO_STRING.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.INT64_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.INT64_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.INT64_TO_STRING))
 .addOverloadTranslator(
 Conversions.UINT64_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.UINT64_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.UINT64_TO_STRING))
 .addOverloadTranslator(
 Conversions.DOUBLE_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DOUBLE_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.DOUBLE_TO_STRING))
 .addOverloadTranslator(
 Conversions.BOOL_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.BOOL_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.BOOL_TO_STRING))
 .addOverloadTranslator(
 Conversions.BYTES_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.BYTES_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.BYTES_TO_STRING))
 .addOverloadTranslator(
 Conversions.TIMESTAMP_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.TIMESTAMP_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.TIMESTAMP_TO_STRING))
 .addOverloadTranslator(
 Conversions.DURATION_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DURATION_TO_STRING),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.DURATION_TO_STRING))
 .build();

 private static final CelZ3FunctionAxiom BYTES_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.BYTES.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.BYTES_TO_BYTES.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_BYTES.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_BYTES),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_BYTES))
 .build();

 private static final CelZ3FunctionAxiom DYN_AXIOM =
Expand All@@ -156,21 +143,19 @@ final class TypeConversionAxioms {
 .addUnaryOverloadTranslator(
 Conversions.DURATION_TO_DURATION.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_DURATION.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_DURATION),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_DURATION))
 .build();

 private static final CelZ3FunctionAxiom TIMESTAMP_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.TIMESTAMP.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.TIMESTAMP_TO_TIMESTAMP.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_TIMESTAMP.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_TIMESTAMP),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_TIMESTAMP))
 .addUnaryOverloadTranslator(
 Conversions.INT64_TO_TIMESTAMP.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> {
Expand All@@ -186,10 +171,9 @@ final class TypeConversionAxioms {
 .addUnaryOverloadTranslator(
 Conversions.BOOL_TO_BOOL.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_BOOL.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_BOOL),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_BOOL))
 .build();

 static final ImmutableList<CelZ3FunctionAxiom> ALL_AXIOMS =
Expand All@@ -204,64 +188,77 @@ final class TypeConversionAxioms {
 TIMESTAMP_AXIOM,
 BOOL_AXIOM);

 private static CelZ3FunctionAxiom.UnaryTranslator createUninterpretedConversion(
 Conversions conversion) {
 return (ctx, typeSystem, sink, arg) -> {
 private static CelZ3OverloadTranslator createUninterpretedConversion(Conversions conversion) {
 return (ctx, typeSystem, sink, unwrappedArgs, argApproximations) -> {
 Expr<?> arg = unwrappedArgs.get(0);
 BoolExpr baseApprox = argApproximations.get(0);

 FuncDecl<?> funcDecl =
 typeSystem.internFuncDecl(
 conversion.celOverloadDecl().overloadId(),
 new Sort[] {typeSystem.celValueSort()},
 typeSystem.celValueSort());
 Expr<?> res = ctx.mkApp(funcDecl, arg);

 BoolExpr isValid;
 switch (conversion.celOverloadDecl().resultType().kind()) {
 case INT:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isInt(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isInt(res),
 ctx.mkNot(typeSystem.checkIntOverflow(typeSystem.getInt(res))));
 ctx.mkNot(typeSystem.checkIntOverflow(typeSystem.getInt(res)))));
 break;
 case TIMESTAMP:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isTimestamp(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isTimestamp(res),
 ctx.mkNot(typeSystem.checkTimestampOverflow(typeSystem.getTimestamp(res))));
 ctx.mkNot(typeSystem.checkTimestampOverflow(typeSystem.getTimestamp(res)))));
 break;
 case DURATION:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isDuration(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isDuration(res),
 ctx.mkNot(typeSystem.checkDurationOverflow(typeSystem.getDuration(res))));
 ctx.mkNot(typeSystem.checkDurationOverflow(typeSystem.getDuration(res)))));
 break;
 case UINT:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isUint(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isUint(res),
 ctx.mkNot(typeSystem.checkUintOverflow(typeSystem.getUint(res))));
 ctx.mkNot(typeSystem.checkUintOverflow(typeSystem.getUint(res)))));
 break;
 case DOUBLE:
 isValid =
 ctx.mkAnd(
 typeSystem.isDouble(res), ctx.mkNot(ctx.mkFPIsNaN(typeSystem.getDouble(res))));
 sink.accept(ctx.mkOr(typeSystem.isDouble(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isDouble(res),
 ctx.mkNot(ctx.mkFPIsNaN((FPExpr) typeSystem.getDouble(res)))));
 break;
 case STRING:
isValid = typeSystem.isString(res);
sink.accept(ctx.mkOr(typeSystem.isString(res), typeSystem.isError(res)));
 break;
 case BYTES:
isValid = typeSystem.isBytes(res);
sink.accept(ctx.mkOr(typeSystem.isBytes(res), typeSystem.isError(res)));
 break;
 case BOOL:
isValid = typeSystem.isBool(res);
sink.accept(ctx.mkOr(typeSystem.isBool(res), typeSystem.isError(res)));
 break;
 default:
 throw new IllegalArgumentException(
 "Unsupported uninterpreted conversion result type: "
 + conversion.celOverloadDecl().resultType());
 }

 sink.accept(ctx.mkOr(isValid, typeSystem.isError(res)));
 return Optional.of(res);
 boolean isArgConstant = typeSystem.isPrimitiveConstant(arg);
 boolean isStringParseConversion =
 conversion.celOverloadDecl().parameterTypes().get(0).equals(SimpleType.STRING);

 BoolExpr finalApprox =
 (!isArgConstant && isStringParseConversion) ? baseApprox : ctx.mkTrue();

 return Optional.of(CelZ3OverloadResult.create(res, finalApprox));
 };
 }

Expand Down

17 changes: 9 additions & 8 deletions
verifier/src/test/java/dev/cel/verifier/CelVerifierZ3ImplTest.java

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Original file line numberDiff line numberDiff line change
Expand Up@@ -154,8 +154,6 @@ private enum IsSatisfiableTestCase {
 NULL_SATISFIABLE("unknown_var == null"),
 DYNAMIC_VAR_NUMERIC_EQUALITY("dyn_var == 1 && dyn_var == 1.0"),
 DYNAMIC_VAR_NOT_IN_LIST("dyn_var == 1.5 && !(dyn_var in dyn_list) && size(dyn_list) > 5"),
 TIMESTAMP_EQUALITY_TAUTOLOGY(
 "timestamp('2023-01-01T00:00:00Z') == timestamp('2023-01-01T00:00:00Z')"),
 CROSS_NUMERIC_EQUALITY_INT_DYN_EXACT("1 == request"),
 MACRO_LIMIT("dyn_list.all(x, x == 1)"),
 STRUCT_FIELD_MISSING_APPROXIMATE_SATISFIABLE("dyn_var.unknown_field"),
Expand DownExpand Up@@ -1353,12 +1351,10 @@ private enum IsAlwaysTrueViolationTestCase {
 "duration(string_var) == duration(string_var)",
 "Condition is not always true\\.",
 "Counterexample input:"),
 // TODO: Implement RFC 3339 spec in conversion
 TIMESTAMP_STRING_CONVERSION_VALID(
 "timestamp('2023-01-01T00:00:00Z') == timestamp('2023-01-01T00:00:00Z')",
 "Condition is not always true\\."),
 DURATION_STRING_CONVERSION_VALID(
 "duration('100s') == duration('100s')", "Condition is not always true\\."),
 UNINTERPRETED_CONVERSION_CAN_ERROR_BOOL_FROM_STRING(
 "bool(string_var) == bool(string_var)",
 "Condition is not always true\\.",
 "Counterexample input:"),
 ;

 final String expr;
Expand All@@ -1384,6 +1380,11 @@ public void isAlwaysTrue_violation_returnsFalse(
 }

 private enum IsInconclusiveTestCase {
 // TODO: Implement RFC 3339 spec in conversion
 TIMESTAMP_STRING_CONVERSION_VALID(
 "timestamp('2023-01-01T00:00:00Z') == timestamp('2023-01-01T00:00:00Z')"),
 DURATION_STRING_CONVERSION_VALID("duration('100s') == duration('100s')"),
 BOOL_STRING_UNINTERPRETED("bool('true') == true"),
 TIMESTAMP_ADD_DURATION_OVERFLOW("timestamp(253402300799) + duration('100s') > timestamp(0)"),
 DYNAMIC_EQUALITY_TIMESTAMP_INT_COLLISION(
 "type(dyn_var) == int && dyn_var == 0 ? dyn_var != timestamp('1970-01-01T00:00:00Z') :"
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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Aug 1, 2026
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Mark uninterpreted conversions with literals as approximate
#1155
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4 changes: 3 additions & 1 deletion
verifier/src/main/java/dev/cel/verifier/CelAstToZ3Translator.java

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Original file line numberDiff line numberDiff line change
Expand Up@@ -741,8 +741,10 @@ private TranslatedValue translateCall(CelExpr expr, CelAbstractSyntaxTree ast) {
 typeConstraints.add(ctx.mkNot(typeSystem.isUnknown(callRes)));
 typeConstraints.add(ctx.mkNot(typeSystem.isError(callRes)));

 boolean isDynamic = ast.getType(exprId).map(SimpleType.DYN::equals).orElse(true);
 BoolExpr isApprox = ctx.mkBool(!isDynamic);
 return TranslatedValue.propagateStrict(
 ctx, typeSystem, callRes, Optional.of(expr), ctx.mkTrue(), args);
 ctx, typeSystem, callRes, Optional.of(expr), isApprox, args);
 });
 }

Expand Down

3 changes: 2 additions & 1 deletion
verifier/src/main/java/dev/cel/verifier/CelZ3OperatorTranslator.java

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Original file line numberDiff line numberDiff line change
Expand Up@@ -594,7 +594,8 @@ private TranslatedValue translateEquality(
 // because X == X is a tautology (or propagates errors/unknowns exactly).
 if (z3Arg0.equals(z3Arg1)) {
 Expr<?> finalResult = typeSystem.propagateErrorAndUnknown(equalityExpr, z3Arg0);
 return TranslatedValue.create(finalResult, typeSystem, ctx.mkFalse());
 return TranslatedValue.create(
 finalResult, typeSystem, ctx.mkOr(arg0.isApproximate(), arg1.isApproximate()));
 }

 return TranslatedValue.propagateStrict(ctx, typeSystem, equalityExpr, arg0, arg1)
Expand Down

30 changes: 30 additions & 0 deletions
verifier/src/main/java/dev/cel/verifier/CelZ3TypeSystem.java

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Original file line numberDiff line numberDiff line change
Expand Up@@ -26,6 +26,7 @@
import com.microsoft.z3.DatatypeSort;
import com.microsoft.z3.Expr;
import com.microsoft.z3.FPExpr;
import com.microsoft.z3.FPNum;
import com.microsoft.z3.FuncDecl;
import com.microsoft.z3.IntExpr;
import com.microsoft.z3.SeqExpr;
Expand DownExpand Up@@ -280,6 +281,35 @@ Constructor optionalCons() {
 return optionalCons;
 }

 /**
 * Checks if the given CelValue expression represents a statically known primitive constant.
 *
 * <p>This is useful for determining whether an uninterpreted function's result should be treated
 * as an approximation. If the argument is a known constant, any resulting error is an
 * approximation (e.g., parsing a literal string). If it's a variable, the error is an exact
 * runtime failure.
 */
 public boolean isPrimitiveConstant(Expr<?> expr) {
 if (!expr.isApp()) {
 return false;
 }
 FuncDecl<?> decl = expr.getFuncDecl();
 if (decl.equals(stringCons.ConstructorDecl()) || decl.equals(bytesCons.ConstructorDecl())) {
 return expr.getArgs()[0].isString();
 } else if (decl.equals(intCons.ConstructorDecl())
 || decl.equals(uintCons.ConstructorDecl())
 || decl.equals(timestampCons.ConstructorDecl())
 || decl.equals(durationCons.ConstructorDecl())) {
 return expr.getArgs()[0].isNumeral();
 } else if (decl.equals(doubleCons.ConstructorDecl())) {
 return expr.getArgs()[0] instanceof FPNum;
 } else if (decl.equals(boolCons.ConstructorDecl())) {
 Expr<?> inner = expr.getArgs()[0];
 return inner.isTrue() || inner.isFalse();
 }
 return false;
 }

 /** Creates a CelValue containing a boolean. */
 public Expr<?> mkBool(boolean val) {
 return ctx.mkApp(boolCons.ConstructorDecl(), ctx.mkBool(val));
Expand Down

153 changes: 75 additions & 78 deletions
verifier/src/main/java/dev/cel/verifier/axioms/TypeConversionAxioms.java

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Original file line numberDiff line numberDiff line change
Expand Up@@ -19,11 +19,13 @@
import com.google.common.collect.ImmutableList;
import com.microsoft.z3.BoolExpr;
import com.microsoft.z3.Expr;
import com.microsoft.z3.FPExpr;
import com.microsoft.z3.FuncDecl;
import com.microsoft.z3.IntExpr;
import com.microsoft.z3.Sort;
import dev.cel.checker.CelStandardDeclarations.StandardFunction;
import dev.cel.checker.CelStandardDeclarations.StandardFunction.Overload.Conversions;
import dev.cel.common.types.SimpleType;
import java.util.Optional;

/** Axiomatization for CEL's type conversion functions. */
Expand All@@ -42,14 +44,12 @@ final class TypeConversionAxioms {
 return Optional.of(
 typeSystem.withRuntimeError(typeSystem.wrapInt(uintVal), outOfBounds));
 })
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.DOUBLE_TO_INT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DOUBLE_TO_INT64),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.DOUBLE_TO_INT64))
 .addOverloadTranslator(
 Conversions.STRING_TO_INT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_INT64),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_INT64))
 .addUnaryOverloadTranslator(
 Conversions.TIMESTAMP_TO_INT64.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) ->
Expand All@@ -69,79 +69,66 @@ final class TypeConversionAxioms {
 return Optional.of(
 typeSystem.withRuntimeError(typeSystem.wrapUint(intVal), outOfBounds));
 })
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.DOUBLE_TO_UINT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DOUBLE_TO_UINT64),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.DOUBLE_TO_UINT64))
 .addOverloadTranslator(
 Conversions.STRING_TO_UINT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_UINT64),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_UINT64))
 .build();

 private static final CelZ3FunctionAxiom DOUBLE_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.DOUBLE.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.DOUBLE_TO_DOUBLE.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.INT64_TO_DOUBLE.celOverloadDecl(),
 createUninterpretedConversion(Conversions.INT64_TO_DOUBLE),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.INT64_TO_DOUBLE))
 .addOverloadTranslator(
 Conversions.UINT64_TO_DOUBLE.celOverloadDecl(),
 createUninterpretedConversion(Conversions.UINT64_TO_DOUBLE),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.UINT64_TO_DOUBLE))
 .addOverloadTranslator(
 Conversions.STRING_TO_DOUBLE.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_DOUBLE),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_DOUBLE))
 .build();

 private static final CelZ3FunctionAxiom STRING_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.STRING.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.STRING_TO_STRING.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.INT64_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.INT64_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.INT64_TO_STRING))
 .addOverloadTranslator(
 Conversions.UINT64_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.UINT64_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.UINT64_TO_STRING))
 .addOverloadTranslator(
 Conversions.DOUBLE_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DOUBLE_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.DOUBLE_TO_STRING))
 .addOverloadTranslator(
 Conversions.BOOL_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.BOOL_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.BOOL_TO_STRING))
 .addOverloadTranslator(
 Conversions.BYTES_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.BYTES_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.BYTES_TO_STRING))
 .addOverloadTranslator(
 Conversions.TIMESTAMP_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.TIMESTAMP_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.TIMESTAMP_TO_STRING))
 .addOverloadTranslator(
 Conversions.DURATION_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DURATION_TO_STRING),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.DURATION_TO_STRING))
 .build();

 private static final CelZ3FunctionAxiom BYTES_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.BYTES.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.BYTES_TO_BYTES.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_BYTES.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_BYTES),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_BYTES))
 .build();

 private static final CelZ3FunctionAxiom DYN_AXIOM =
Expand All@@ -156,21 +143,19 @@ final class TypeConversionAxioms {
 .addUnaryOverloadTranslator(
 Conversions.DURATION_TO_DURATION.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_DURATION.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_DURATION),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_DURATION))
 .build();

 private static final CelZ3FunctionAxiom TIMESTAMP_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.TIMESTAMP.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.TIMESTAMP_TO_TIMESTAMP.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_TIMESTAMP.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_TIMESTAMP),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_TIMESTAMP))
 .addUnaryOverloadTranslator(
 Conversions.INT64_TO_TIMESTAMP.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> {
Expand All@@ -186,10 +171,9 @@ final class TypeConversionAxioms {
 .addUnaryOverloadTranslator(
 Conversions.BOOL_TO_BOOL.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_BOOL.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_BOOL),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_BOOL))
 .build();

 static final ImmutableList<CelZ3FunctionAxiom> ALL_AXIOMS =
Expand All@@ -204,64 +188,77 @@ final class TypeConversionAxioms {
 TIMESTAMP_AXIOM,
 BOOL_AXIOM);

 private static CelZ3FunctionAxiom.UnaryTranslator createUninterpretedConversion(
 Conversions conversion) {
 return (ctx, typeSystem, sink, arg) -> {
 private static CelZ3OverloadTranslator createUninterpretedConversion(Conversions conversion) {
 return (ctx, typeSystem, sink, unwrappedArgs, argApproximations) -> {
 Expr<?> arg = unwrappedArgs.get(0);
 BoolExpr baseApprox = argApproximations.get(0);

 FuncDecl<?> funcDecl =
 typeSystem.internFuncDecl(
 conversion.celOverloadDecl().overloadId(),
 new Sort[] {typeSystem.celValueSort()},
 typeSystem.celValueSort());
 Expr<?> res = ctx.mkApp(funcDecl, arg);

 BoolExpr isValid;
 switch (conversion.celOverloadDecl().resultType().kind()) {
 case INT:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isInt(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isInt(res),
 ctx.mkNot(typeSystem.checkIntOverflow(typeSystem.getInt(res))));
 ctx.mkNot(typeSystem.checkIntOverflow(typeSystem.getInt(res)))));
 break;
 case TIMESTAMP:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isTimestamp(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isTimestamp(res),
 ctx.mkNot(typeSystem.checkTimestampOverflow(typeSystem.getTimestamp(res))));
 ctx.mkNot(typeSystem.checkTimestampOverflow(typeSystem.getTimestamp(res)))));
 break;
 case DURATION:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isDuration(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isDuration(res),
 ctx.mkNot(typeSystem.checkDurationOverflow(typeSystem.getDuration(res))));
 ctx.mkNot(typeSystem.checkDurationOverflow(typeSystem.getDuration(res)))));
 break;
 case UINT:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isUint(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isUint(res),
 ctx.mkNot(typeSystem.checkUintOverflow(typeSystem.getUint(res))));
 ctx.mkNot(typeSystem.checkUintOverflow(typeSystem.getUint(res)))));
 break;
 case DOUBLE:
 isValid =
 ctx.mkAnd(
 typeSystem.isDouble(res), ctx.mkNot(ctx.mkFPIsNaN(typeSystem.getDouble(res))));
 sink.accept(ctx.mkOr(typeSystem.isDouble(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isDouble(res),
 ctx.mkNot(ctx.mkFPIsNaN((FPExpr) typeSystem.getDouble(res)))));
 break;
 case STRING:
isValid = typeSystem.isString(res);
sink.accept(ctx.mkOr(typeSystem.isString(res), typeSystem.isError(res)));
 break;
 case BYTES:
isValid = typeSystem.isBytes(res);
sink.accept(ctx.mkOr(typeSystem.isBytes(res), typeSystem.isError(res)));
 break;
 case BOOL:
isValid = typeSystem.isBool(res);
sink.accept(ctx.mkOr(typeSystem.isBool(res), typeSystem.isError(res)));
 break;
 default:
 throw new IllegalArgumentException(
 "Unsupported uninterpreted conversion result type: "
 + conversion.celOverloadDecl().resultType());
 }

 sink.accept(ctx.mkOr(isValid, typeSystem.isError(res)));
 return Optional.of(res);
 boolean isArgConstant = typeSystem.isPrimitiveConstant(arg);
 boolean isStringParseConversion =
 conversion.celOverloadDecl().parameterTypes().get(0).equals(SimpleType.STRING);

 BoolExpr finalApprox =
 (!isArgConstant && isStringParseConversion) ? baseApprox : ctx.mkTrue();

 return Optional.of(CelZ3OverloadResult.create(res, finalApprox));
 };
 }

Expand Down

17 changes: 9 additions & 8 deletions
verifier/src/test/java/dev/cel/verifier/CelVerifierZ3ImplTest.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -154,8 +154,6 @@ private enum IsSatisfiableTestCase {
 NULL_SATISFIABLE("unknown_var == null"),
 DYNAMIC_VAR_NUMERIC_EQUALITY("dyn_var == 1 && dyn_var == 1.0"),
 DYNAMIC_VAR_NOT_IN_LIST("dyn_var == 1.5 && !(dyn_var in dyn_list) && size(dyn_list) > 5"),
 TIMESTAMP_EQUALITY_TAUTOLOGY(
 "timestamp('2023-01-01T00:00:00Z') == timestamp('2023-01-01T00:00:00Z')"),
 CROSS_NUMERIC_EQUALITY_INT_DYN_EXACT("1 == request"),
 MACRO_LIMIT("dyn_list.all(x, x == 1)"),
 STRUCT_FIELD_MISSING_APPROXIMATE_SATISFIABLE("dyn_var.unknown_field"),
Expand DownExpand Up@@ -1353,12 +1351,10 @@ private enum IsAlwaysTrueViolationTestCase {
 "duration(string_var) == duration(string_var)",
 "Condition is not always true\\.",
 "Counterexample input:"),
 // TODO: Implement RFC 3339 spec in conversion
 TIMESTAMP_STRING_CONVERSION_VALID(
 "timestamp('2023-01-01T00:00:00Z') == timestamp('2023-01-01T00:00:00Z')",
 "Condition is not always true\\."),
 DURATION_STRING_CONVERSION_VALID(
 "duration('100s') == duration('100s')", "Condition is not always true\\."),
 UNINTERPRETED_CONVERSION_CAN_ERROR_BOOL_FROM_STRING(
 "bool(string_var) == bool(string_var)",
 "Condition is not always true\\.",
 "Counterexample input:"),
 ;

 final String expr;
Expand All@@ -1384,6 +1380,11 @@ public void isAlwaysTrue_violation_returnsFalse(
 }

 private enum IsInconclusiveTestCase {
 // TODO: Implement RFC 3339 spec in conversion
 TIMESTAMP_STRING_CONVERSION_VALID(
 "timestamp('2023-01-01T00:00:00Z') == timestamp('2023-01-01T00:00:00Z')"),
 DURATION_STRING_CONVERSION_VALID("duration('100s') == duration('100s')"),
 BOOL_STRING_UNINTERPRETED("bool('true') == true"),
 TIMESTAMP_ADD_DURATION_OVERFLOW("timestamp(253402300799) + duration('100s') > timestamp(0)"),
 DYNAMIC_EQUALITY_TIMESTAMP_INT_COLLISION(
 "type(dyn_var) == int && dyn_var == 0 ? dyn_var != timestamp('1970-01-01T00:00:00Z') :"
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

Skip to content
Mark uninterpreted conversions with literals as approximate#1155

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copybara-service
merged 1 commit into

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Aug 1, 2026
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Mark uninterpreted conversions with literals as approximate
#1155
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4 changes: 3 additions & 1 deletion
verifier/src/main/java/dev/cel/verifier/CelAstToZ3Translator.java

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Original file line numberDiff line numberDiff line change
Expand Up@@ -741,8 +741,10 @@ private TranslatedValue translateCall(CelExpr expr, CelAbstractSyntaxTree ast) {
 typeConstraints.add(ctx.mkNot(typeSystem.isUnknown(callRes)));
 typeConstraints.add(ctx.mkNot(typeSystem.isError(callRes)));

 boolean isDynamic = ast.getType(exprId).map(SimpleType.DYN::equals).orElse(true);
 BoolExpr isApprox = ctx.mkBool(!isDynamic);
 return TranslatedValue.propagateStrict(
 ctx, typeSystem, callRes, Optional.of(expr), ctx.mkTrue(), args);
 ctx, typeSystem, callRes, Optional.of(expr), isApprox, args);
 });
 }

Expand Down

3 changes: 2 additions & 1 deletion
verifier/src/main/java/dev/cel/verifier/CelZ3OperatorTranslator.java

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Original file line numberDiff line numberDiff line change
Expand Up@@ -594,7 +594,8 @@ private TranslatedValue translateEquality(
 // because X == X is a tautology (or propagates errors/unknowns exactly).
 if (z3Arg0.equals(z3Arg1)) {
 Expr<?> finalResult = typeSystem.propagateErrorAndUnknown(equalityExpr, z3Arg0);
 return TranslatedValue.create(finalResult, typeSystem, ctx.mkFalse());
 return TranslatedValue.create(
 finalResult, typeSystem, ctx.mkOr(arg0.isApproximate(), arg1.isApproximate()));
 }

 return TranslatedValue.propagateStrict(ctx, typeSystem, equalityExpr, arg0, arg1)
Expand Down

30 changes: 30 additions & 0 deletions
verifier/src/main/java/dev/cel/verifier/CelZ3TypeSystem.java

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Original file line numberDiff line numberDiff line change
Expand Up@@ -26,6 +26,7 @@
import com.microsoft.z3.DatatypeSort;
import com.microsoft.z3.Expr;
import com.microsoft.z3.FPExpr;
import com.microsoft.z3.FPNum;
import com.microsoft.z3.FuncDecl;
import com.microsoft.z3.IntExpr;
import com.microsoft.z3.SeqExpr;
Expand DownExpand Up@@ -280,6 +281,35 @@ Constructor optionalCons() {
 return optionalCons;
 }

 /**
 * Checks if the given CelValue expression represents a statically known primitive constant.
 *
 * <p>This is useful for determining whether an uninterpreted function's result should be treated
 * as an approximation. If the argument is a known constant, any resulting error is an
 * approximation (e.g., parsing a literal string). If it's a variable, the error is an exact
 * runtime failure.
 */
 public boolean isPrimitiveConstant(Expr<?> expr) {
 if (!expr.isApp()) {
 return false;
 }
 FuncDecl<?> decl = expr.getFuncDecl();
 if (decl.equals(stringCons.ConstructorDecl()) || decl.equals(bytesCons.ConstructorDecl())) {
 return expr.getArgs()[0].isString();
 } else if (decl.equals(intCons.ConstructorDecl())
 || decl.equals(uintCons.ConstructorDecl())
 || decl.equals(timestampCons.ConstructorDecl())
 || decl.equals(durationCons.ConstructorDecl())) {
 return expr.getArgs()[0].isNumeral();
 } else if (decl.equals(doubleCons.ConstructorDecl())) {
 return expr.getArgs()[0] instanceof FPNum;
 } else if (decl.equals(boolCons.ConstructorDecl())) {
 Expr<?> inner = expr.getArgs()[0];
 return inner.isTrue() || inner.isFalse();
 }
 return false;
 }

 /** Creates a CelValue containing a boolean. */
 public Expr<?> mkBool(boolean val) {
 return ctx.mkApp(boolCons.ConstructorDecl(), ctx.mkBool(val));
Expand Down

153 changes: 75 additions & 78 deletions
verifier/src/main/java/dev/cel/verifier/axioms/TypeConversionAxioms.java

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Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -19,11 +19,13 @@
import com.google.common.collect.ImmutableList;
import com.microsoft.z3.BoolExpr;
import com.microsoft.z3.Expr;
import com.microsoft.z3.FPExpr;
import com.microsoft.z3.FuncDecl;
import com.microsoft.z3.IntExpr;
import com.microsoft.z3.Sort;
import dev.cel.checker.CelStandardDeclarations.StandardFunction;
import dev.cel.checker.CelStandardDeclarations.StandardFunction.Overload.Conversions;
import dev.cel.common.types.SimpleType;
import java.util.Optional;

/** Axiomatization for CEL's type conversion functions. */
Expand All@@ -42,14 +44,12 @@ final class TypeConversionAxioms {
 return Optional.of(
 typeSystem.withRuntimeError(typeSystem.wrapInt(uintVal), outOfBounds));
 })
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.DOUBLE_TO_INT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DOUBLE_TO_INT64),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.DOUBLE_TO_INT64))
 .addOverloadTranslator(
 Conversions.STRING_TO_INT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_INT64),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_INT64))
 .addUnaryOverloadTranslator(
 Conversions.TIMESTAMP_TO_INT64.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) ->
Expand All@@ -69,79 +69,66 @@ final class TypeConversionAxioms {
 return Optional.of(
 typeSystem.withRuntimeError(typeSystem.wrapUint(intVal), outOfBounds));
 })
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.DOUBLE_TO_UINT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DOUBLE_TO_UINT64),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.DOUBLE_TO_UINT64))
 .addOverloadTranslator(
 Conversions.STRING_TO_UINT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_UINT64),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_UINT64))
 .build();

 private static final CelZ3FunctionAxiom DOUBLE_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.DOUBLE.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.DOUBLE_TO_DOUBLE.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.INT64_TO_DOUBLE.celOverloadDecl(),
 createUninterpretedConversion(Conversions.INT64_TO_DOUBLE),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.INT64_TO_DOUBLE))
 .addOverloadTranslator(
 Conversions.UINT64_TO_DOUBLE.celOverloadDecl(),
 createUninterpretedConversion(Conversions.UINT64_TO_DOUBLE),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.UINT64_TO_DOUBLE))
 .addOverloadTranslator(
 Conversions.STRING_TO_DOUBLE.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_DOUBLE),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_DOUBLE))
 .build();

 private static final CelZ3FunctionAxiom STRING_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.STRING.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.STRING_TO_STRING.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.INT64_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.INT64_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.INT64_TO_STRING))
 .addOverloadTranslator(
 Conversions.UINT64_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.UINT64_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.UINT64_TO_STRING))
 .addOverloadTranslator(
 Conversions.DOUBLE_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DOUBLE_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.DOUBLE_TO_STRING))
 .addOverloadTranslator(
 Conversions.BOOL_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.BOOL_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.BOOL_TO_STRING))
 .addOverloadTranslator(
 Conversions.BYTES_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.BYTES_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.BYTES_TO_STRING))
 .addOverloadTranslator(
 Conversions.TIMESTAMP_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.TIMESTAMP_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.TIMESTAMP_TO_STRING))
 .addOverloadTranslator(
 Conversions.DURATION_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DURATION_TO_STRING),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.DURATION_TO_STRING))
 .build();

 private static final CelZ3FunctionAxiom BYTES_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.BYTES.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.BYTES_TO_BYTES.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_BYTES.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_BYTES),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_BYTES))
 .build();

 private static final CelZ3FunctionAxiom DYN_AXIOM =
Expand All@@ -156,21 +143,19 @@ final class TypeConversionAxioms {
 .addUnaryOverloadTranslator(
 Conversions.DURATION_TO_DURATION.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_DURATION.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_DURATION),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_DURATION))
 .build();

 private static final CelZ3FunctionAxiom TIMESTAMP_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.TIMESTAMP.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.TIMESTAMP_TO_TIMESTAMP.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_TIMESTAMP.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_TIMESTAMP),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_TIMESTAMP))
 .addUnaryOverloadTranslator(
 Conversions.INT64_TO_TIMESTAMP.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> {
Expand All@@ -186,10 +171,9 @@ final class TypeConversionAxioms {
 .addUnaryOverloadTranslator(
 Conversions.BOOL_TO_BOOL.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_BOOL.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_BOOL),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_BOOL))
 .build();

 static final ImmutableList<CelZ3FunctionAxiom> ALL_AXIOMS =
Expand All@@ -204,64 +188,77 @@ final class TypeConversionAxioms {
 TIMESTAMP_AXIOM,
 BOOL_AXIOM);

 private static CelZ3FunctionAxiom.UnaryTranslator createUninterpretedConversion(
 Conversions conversion) {
 return (ctx, typeSystem, sink, arg) -> {
 private static CelZ3OverloadTranslator createUninterpretedConversion(Conversions conversion) {
 return (ctx, typeSystem, sink, unwrappedArgs, argApproximations) -> {
 Expr<?> arg = unwrappedArgs.get(0);
 BoolExpr baseApprox = argApproximations.get(0);

 FuncDecl<?> funcDecl =
 typeSystem.internFuncDecl(
 conversion.celOverloadDecl().overloadId(),
 new Sort[] {typeSystem.celValueSort()},
 typeSystem.celValueSort());
 Expr<?> res = ctx.mkApp(funcDecl, arg);

 BoolExpr isValid;
 switch (conversion.celOverloadDecl().resultType().kind()) {
 case INT:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isInt(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isInt(res),
 ctx.mkNot(typeSystem.checkIntOverflow(typeSystem.getInt(res))));
 ctx.mkNot(typeSystem.checkIntOverflow(typeSystem.getInt(res)))));
 break;
 case TIMESTAMP:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isTimestamp(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isTimestamp(res),
 ctx.mkNot(typeSystem.checkTimestampOverflow(typeSystem.getTimestamp(res))));
 ctx.mkNot(typeSystem.checkTimestampOverflow(typeSystem.getTimestamp(res)))));
 break;
 case DURATION:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isDuration(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isDuration(res),
 ctx.mkNot(typeSystem.checkDurationOverflow(typeSystem.getDuration(res))));
 ctx.mkNot(typeSystem.checkDurationOverflow(typeSystem.getDuration(res)))));
 break;
 case UINT:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isUint(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isUint(res),
 ctx.mkNot(typeSystem.checkUintOverflow(typeSystem.getUint(res))));
 ctx.mkNot(typeSystem.checkUintOverflow(typeSystem.getUint(res)))));
 break;
 case DOUBLE:
 isValid =
 ctx.mkAnd(
 typeSystem.isDouble(res), ctx.mkNot(ctx.mkFPIsNaN(typeSystem.getDouble(res))));
 sink.accept(ctx.mkOr(typeSystem.isDouble(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isDouble(res),
 ctx.mkNot(ctx.mkFPIsNaN((FPExpr) typeSystem.getDouble(res)))));
 break;
 case STRING:
isValid = typeSystem.isString(res);
sink.accept(ctx.mkOr(typeSystem.isString(res), typeSystem.isError(res)));
 break;
 case BYTES:
isValid = typeSystem.isBytes(res);
sink.accept(ctx.mkOr(typeSystem.isBytes(res), typeSystem.isError(res)));
 break;
 case BOOL:
isValid = typeSystem.isBool(res);
sink.accept(ctx.mkOr(typeSystem.isBool(res), typeSystem.isError(res)));
 break;
 default:
 throw new IllegalArgumentException(
 "Unsupported uninterpreted conversion result type: "
 + conversion.celOverloadDecl().resultType());
 }

 sink.accept(ctx.mkOr(isValid, typeSystem.isError(res)));
 return Optional.of(res);
 boolean isArgConstant = typeSystem.isPrimitiveConstant(arg);
 boolean isStringParseConversion =
 conversion.celOverloadDecl().parameterTypes().get(0).equals(SimpleType.STRING);

 BoolExpr finalApprox =
 (!isArgConstant && isStringParseConversion) ? baseApprox : ctx.mkTrue();

 return Optional.of(CelZ3OverloadResult.create(res, finalApprox));
 };
 }

Expand Down

17 changes: 9 additions & 8 deletions
verifier/src/test/java/dev/cel/verifier/CelVerifierZ3ImplTest.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -154,8 +154,6 @@ private enum IsSatisfiableTestCase {
 NULL_SATISFIABLE("unknown_var == null"),
 DYNAMIC_VAR_NUMERIC_EQUALITY("dyn_var == 1 && dyn_var == 1.0"),
 DYNAMIC_VAR_NOT_IN_LIST("dyn_var == 1.5 && !(dyn_var in dyn_list) && size(dyn_list) > 5"),
 TIMESTAMP_EQUALITY_TAUTOLOGY(
 "timestamp('2023-01-01T00:00:00Z') == timestamp('2023-01-01T00:00:00Z')"),
 CROSS_NUMERIC_EQUALITY_INT_DYN_EXACT("1 == request"),
 MACRO_LIMIT("dyn_list.all(x, x == 1)"),
 STRUCT_FIELD_MISSING_APPROXIMATE_SATISFIABLE("dyn_var.unknown_field"),
Expand DownExpand Up@@ -1353,12 +1351,10 @@ private enum IsAlwaysTrueViolationTestCase {
 "duration(string_var) == duration(string_var)",
 "Condition is not always true\\.",
 "Counterexample input:"),
 // TODO: Implement RFC 3339 spec in conversion
 TIMESTAMP_STRING_CONVERSION_VALID(
 "timestamp('2023-01-01T00:00:00Z') == timestamp('2023-01-01T00:00:00Z')",
 "Condition is not always true\\."),
 DURATION_STRING_CONVERSION_VALID(
 "duration('100s') == duration('100s')", "Condition is not always true\\."),
 UNINTERPRETED_CONVERSION_CAN_ERROR_BOOL_FROM_STRING(
 "bool(string_var) == bool(string_var)",
 "Condition is not always true\\.",
 "Counterexample input:"),
 ;

 final String expr;
Expand All@@ -1384,6 +1380,11 @@ public void isAlwaysTrue_violation_returnsFalse(
 }

 private enum IsInconclusiveTestCase {
 // TODO: Implement RFC 3339 spec in conversion
 TIMESTAMP_STRING_CONVERSION_VALID(
 "timestamp('2023-01-01T00:00:00Z') == timestamp('2023-01-01T00:00:00Z')"),
 DURATION_STRING_CONVERSION_VALID("duration('100s') == duration('100s')"),
 BOOL_STRING_UNINTERPRETED("bool('true') == true"),
 TIMESTAMP_ADD_DURATION_OVERFLOW("timestamp(253402300799) + duration('100s') > timestamp(0)"),
 DYNAMIC_EQUALITY_TIMESTAMP_INT_COLLISION(
 "type(dyn_var) == int && dyn_var == 0 ? dyn_var != timestamp('1970-01-01T00:00:00Z') :"
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
Mark uninterpreted conversions with literals as approximate#1155

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Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

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By clicking “Sign up for GitHub”, you agree to our terms of service and
privacy statement. We’ll occasionally send you account related emails.

Already on GitHub?
Sign in
to your account

 Merged

copybara-service
merged 1 commit into

from

Aug 1, 2026
 Merged


Mark uninterpreted conversions with literals as approximate
#1155
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4 changes: 3 additions & 1 deletion
verifier/src/main/java/dev/cel/verifier/CelAstToZ3Translator.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -741,8 +741,10 @@ private TranslatedValue translateCall(CelExpr expr, CelAbstractSyntaxTree ast) {
 typeConstraints.add(ctx.mkNot(typeSystem.isUnknown(callRes)));
 typeConstraints.add(ctx.mkNot(typeSystem.isError(callRes)));

 boolean isDynamic = ast.getType(exprId).map(SimpleType.DYN::equals).orElse(true);
 BoolExpr isApprox = ctx.mkBool(!isDynamic);
 return TranslatedValue.propagateStrict(
 ctx, typeSystem, callRes, Optional.of(expr), ctx.mkTrue(), args);
 ctx, typeSystem, callRes, Optional.of(expr), isApprox, args);
 });
 }

Expand Down

3 changes: 2 additions & 1 deletion
verifier/src/main/java/dev/cel/verifier/CelZ3OperatorTranslator.java

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Original file line numberDiff line numberDiff line change
Expand Up@@ -594,7 +594,8 @@ private TranslatedValue translateEquality(
 // because X == X is a tautology (or propagates errors/unknowns exactly).
 if (z3Arg0.equals(z3Arg1)) {
 Expr<?> finalResult = typeSystem.propagateErrorAndUnknown(equalityExpr, z3Arg0);
 return TranslatedValue.create(finalResult, typeSystem, ctx.mkFalse());
 return TranslatedValue.create(
 finalResult, typeSystem, ctx.mkOr(arg0.isApproximate(), arg1.isApproximate()));
 }

 return TranslatedValue.propagateStrict(ctx, typeSystem, equalityExpr, arg0, arg1)
Expand Down

30 changes: 30 additions & 0 deletions
verifier/src/main/java/dev/cel/verifier/CelZ3TypeSystem.java

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Original file line numberDiff line numberDiff line change
Expand Up@@ -26,6 +26,7 @@
import com.microsoft.z3.DatatypeSort;
import com.microsoft.z3.Expr;
import com.microsoft.z3.FPExpr;
import com.microsoft.z3.FPNum;
import com.microsoft.z3.FuncDecl;
import com.microsoft.z3.IntExpr;
import com.microsoft.z3.SeqExpr;
Expand DownExpand Up@@ -280,6 +281,35 @@ Constructor optionalCons() {
 return optionalCons;
 }

 /**
 * Checks if the given CelValue expression represents a statically known primitive constant.
 *
 * <p>This is useful for determining whether an uninterpreted function's result should be treated
 * as an approximation. If the argument is a known constant, any resulting error is an
 * approximation (e.g., parsing a literal string). If it's a variable, the error is an exact
 * runtime failure.
 */
 public boolean isPrimitiveConstant(Expr<?> expr) {
 if (!expr.isApp()) {
 return false;
 }
 FuncDecl<?> decl = expr.getFuncDecl();
 if (decl.equals(stringCons.ConstructorDecl()) || decl.equals(bytesCons.ConstructorDecl())) {
 return expr.getArgs()[0].isString();
 } else if (decl.equals(intCons.ConstructorDecl())
 || decl.equals(uintCons.ConstructorDecl())
 || decl.equals(timestampCons.ConstructorDecl())
 || decl.equals(durationCons.ConstructorDecl())) {
 return expr.getArgs()[0].isNumeral();
 } else if (decl.equals(doubleCons.ConstructorDecl())) {
 return expr.getArgs()[0] instanceof FPNum;
 } else if (decl.equals(boolCons.ConstructorDecl())) {
 Expr<?> inner = expr.getArgs()[0];
 return inner.isTrue() || inner.isFalse();
 }
 return false;
 }

 /** Creates a CelValue containing a boolean. */
 public Expr<?> mkBool(boolean val) {
 return ctx.mkApp(boolCons.ConstructorDecl(), ctx.mkBool(val));
Expand Down

153 changes: 75 additions & 78 deletions
verifier/src/main/java/dev/cel/verifier/axioms/TypeConversionAxioms.java

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Original file line numberDiff line numberDiff line change
Expand Up@@ -19,11 +19,13 @@
import com.google.common.collect.ImmutableList;
import com.microsoft.z3.BoolExpr;
import com.microsoft.z3.Expr;
import com.microsoft.z3.FPExpr;
import com.microsoft.z3.FuncDecl;
import com.microsoft.z3.IntExpr;
import com.microsoft.z3.Sort;
import dev.cel.checker.CelStandardDeclarations.StandardFunction;
import dev.cel.checker.CelStandardDeclarations.StandardFunction.Overload.Conversions;
import dev.cel.common.types.SimpleType;
import java.util.Optional;

/** Axiomatization for CEL's type conversion functions. */
Expand All@@ -42,14 +44,12 @@ final class TypeConversionAxioms {
 return Optional.of(
 typeSystem.withRuntimeError(typeSystem.wrapInt(uintVal), outOfBounds));
 })
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.DOUBLE_TO_INT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DOUBLE_TO_INT64),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.DOUBLE_TO_INT64))
 .addOverloadTranslator(
 Conversions.STRING_TO_INT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_INT64),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_INT64))
 .addUnaryOverloadTranslator(
 Conversions.TIMESTAMP_TO_INT64.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) ->
Expand All@@ -69,79 +69,66 @@ final class TypeConversionAxioms {
 return Optional.of(
 typeSystem.withRuntimeError(typeSystem.wrapUint(intVal), outOfBounds));
 })
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.DOUBLE_TO_UINT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DOUBLE_TO_UINT64),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.DOUBLE_TO_UINT64))
 .addOverloadTranslator(
 Conversions.STRING_TO_UINT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_UINT64),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_UINT64))
 .build();

 private static final CelZ3FunctionAxiom DOUBLE_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.DOUBLE.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.DOUBLE_TO_DOUBLE.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.INT64_TO_DOUBLE.celOverloadDecl(),
 createUninterpretedConversion(Conversions.INT64_TO_DOUBLE),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.INT64_TO_DOUBLE))
 .addOverloadTranslator(
 Conversions.UINT64_TO_DOUBLE.celOverloadDecl(),
 createUninterpretedConversion(Conversions.UINT64_TO_DOUBLE),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.UINT64_TO_DOUBLE))
 .addOverloadTranslator(
 Conversions.STRING_TO_DOUBLE.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_DOUBLE),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_DOUBLE))
 .build();

 private static final CelZ3FunctionAxiom STRING_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.STRING.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.STRING_TO_STRING.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.INT64_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.INT64_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.INT64_TO_STRING))
 .addOverloadTranslator(
 Conversions.UINT64_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.UINT64_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.UINT64_TO_STRING))
 .addOverloadTranslator(
 Conversions.DOUBLE_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DOUBLE_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.DOUBLE_TO_STRING))
 .addOverloadTranslator(
 Conversions.BOOL_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.BOOL_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.BOOL_TO_STRING))
 .addOverloadTranslator(
 Conversions.BYTES_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.BYTES_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.BYTES_TO_STRING))
 .addOverloadTranslator(
 Conversions.TIMESTAMP_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.TIMESTAMP_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.TIMESTAMP_TO_STRING))
 .addOverloadTranslator(
 Conversions.DURATION_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DURATION_TO_STRING),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.DURATION_TO_STRING))
 .build();

 private static final CelZ3FunctionAxiom BYTES_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.BYTES.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.BYTES_TO_BYTES.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_BYTES.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_BYTES),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_BYTES))
 .build();

 private static final CelZ3FunctionAxiom DYN_AXIOM =
Expand All@@ -156,21 +143,19 @@ final class TypeConversionAxioms {
 .addUnaryOverloadTranslator(
 Conversions.DURATION_TO_DURATION.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_DURATION.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_DURATION),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_DURATION))
 .build();

 private static final CelZ3FunctionAxiom TIMESTAMP_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.TIMESTAMP.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.TIMESTAMP_TO_TIMESTAMP.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_TIMESTAMP.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_TIMESTAMP),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_TIMESTAMP))
 .addUnaryOverloadTranslator(
 Conversions.INT64_TO_TIMESTAMP.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> {
Expand All@@ -186,10 +171,9 @@ final class TypeConversionAxioms {
 .addUnaryOverloadTranslator(
 Conversions.BOOL_TO_BOOL.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_BOOL.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_BOOL),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_BOOL))
 .build();

 static final ImmutableList<CelZ3FunctionAxiom> ALL_AXIOMS =
Expand All@@ -204,64 +188,77 @@ final class TypeConversionAxioms {
 TIMESTAMP_AXIOM,
 BOOL_AXIOM);

 private static CelZ3FunctionAxiom.UnaryTranslator createUninterpretedConversion(
 Conversions conversion) {
 return (ctx, typeSystem, sink, arg) -> {
 private static CelZ3OverloadTranslator createUninterpretedConversion(Conversions conversion) {
 return (ctx, typeSystem, sink, unwrappedArgs, argApproximations) -> {
 Expr<?> arg = unwrappedArgs.get(0);
 BoolExpr baseApprox = argApproximations.get(0);

 FuncDecl<?> funcDecl =
 typeSystem.internFuncDecl(
 conversion.celOverloadDecl().overloadId(),
 new Sort[] {typeSystem.celValueSort()},
 typeSystem.celValueSort());
 Expr<?> res = ctx.mkApp(funcDecl, arg);

 BoolExpr isValid;
 switch (conversion.celOverloadDecl().resultType().kind()) {
 case INT:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isInt(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isInt(res),
 ctx.mkNot(typeSystem.checkIntOverflow(typeSystem.getInt(res))));
 ctx.mkNot(typeSystem.checkIntOverflow(typeSystem.getInt(res)))));
 break;
 case TIMESTAMP:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isTimestamp(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isTimestamp(res),
 ctx.mkNot(typeSystem.checkTimestampOverflow(typeSystem.getTimestamp(res))));
 ctx.mkNot(typeSystem.checkTimestampOverflow(typeSystem.getTimestamp(res)))));
 break;
 case DURATION:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isDuration(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isDuration(res),
 ctx.mkNot(typeSystem.checkDurationOverflow(typeSystem.getDuration(res))));
 ctx.mkNot(typeSystem.checkDurationOverflow(typeSystem.getDuration(res)))));
 break;
 case UINT:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isUint(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isUint(res),
 ctx.mkNot(typeSystem.checkUintOverflow(typeSystem.getUint(res))));
 ctx.mkNot(typeSystem.checkUintOverflow(typeSystem.getUint(res)))));
 break;
 case DOUBLE:
 isValid =
 ctx.mkAnd(
 typeSystem.isDouble(res), ctx.mkNot(ctx.mkFPIsNaN(typeSystem.getDouble(res))));
 sink.accept(ctx.mkOr(typeSystem.isDouble(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isDouble(res),
 ctx.mkNot(ctx.mkFPIsNaN((FPExpr) typeSystem.getDouble(res)))));
 break;
 case STRING:
isValid = typeSystem.isString(res);
sink.accept(ctx.mkOr(typeSystem.isString(res), typeSystem.isError(res)));
 break;
 case BYTES:
isValid = typeSystem.isBytes(res);
sink.accept(ctx.mkOr(typeSystem.isBytes(res), typeSystem.isError(res)));
 break;
 case BOOL:
isValid = typeSystem.isBool(res);
sink.accept(ctx.mkOr(typeSystem.isBool(res), typeSystem.isError(res)));
 break;
 default:
 throw new IllegalArgumentException(
 "Unsupported uninterpreted conversion result type: "
 + conversion.celOverloadDecl().resultType());
 }

 sink.accept(ctx.mkOr(isValid, typeSystem.isError(res)));
 return Optional.of(res);
 boolean isArgConstant = typeSystem.isPrimitiveConstant(arg);
 boolean isStringParseConversion =
 conversion.celOverloadDecl().parameterTypes().get(0).equals(SimpleType.STRING);

 BoolExpr finalApprox =
 (!isArgConstant && isStringParseConversion) ? baseApprox : ctx.mkTrue();

 return Optional.of(CelZ3OverloadResult.create(res, finalApprox));
 };
 }

Expand Down

17 changes: 9 additions & 8 deletions
verifier/src/test/java/dev/cel/verifier/CelVerifierZ3ImplTest.java

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Original file line numberDiff line numberDiff line change
Expand Up@@ -154,8 +154,6 @@ private enum IsSatisfiableTestCase {
 NULL_SATISFIABLE("unknown_var == null"),
 DYNAMIC_VAR_NUMERIC_EQUALITY("dyn_var == 1 && dyn_var == 1.0"),
 DYNAMIC_VAR_NOT_IN_LIST("dyn_var == 1.5 && !(dyn_var in dyn_list) && size(dyn_list) > 5"),
 TIMESTAMP_EQUALITY_TAUTOLOGY(
 "timestamp('2023-01-01T00:00:00Z') == timestamp('2023-01-01T00:00:00Z')"),
 CROSS_NUMERIC_EQUALITY_INT_DYN_EXACT("1 == request"),
 MACRO_LIMIT("dyn_list.all(x, x == 1)"),
 STRUCT_FIELD_MISSING_APPROXIMATE_SATISFIABLE("dyn_var.unknown_field"),
Expand DownExpand Up@@ -1353,12 +1351,10 @@ private enum IsAlwaysTrueViolationTestCase {
 "duration(string_var) == duration(string_var)",
 "Condition is not always true\\.",
 "Counterexample input:"),
 // TODO: Implement RFC 3339 spec in conversion
 TIMESTAMP_STRING_CONVERSION_VALID(
 "timestamp('2023-01-01T00:00:00Z') == timestamp('2023-01-01T00:00:00Z')",
 "Condition is not always true\\."),
 DURATION_STRING_CONVERSION_VALID(
 "duration('100s') == duration('100s')", "Condition is not always true\\."),
 UNINTERPRETED_CONVERSION_CAN_ERROR_BOOL_FROM_STRING(
 "bool(string_var) == bool(string_var)",
 "Condition is not always true\\.",
 "Counterexample input:"),
 ;

 final String expr;
Expand All@@ -1384,6 +1380,11 @@ public void isAlwaysTrue_violation_returnsFalse(
 }

 private enum IsInconclusiveTestCase {
 // TODO: Implement RFC 3339 spec in conversion
 TIMESTAMP_STRING_CONVERSION_VALID(
 "timestamp('2023-01-01T00:00:00Z') == timestamp('2023-01-01T00:00:00Z')"),
 DURATION_STRING_CONVERSION_VALID("duration('100s') == duration('100s')"),
 BOOL_STRING_UNINTERPRETED("bool('true') == true"),
 TIMESTAMP_ADD_DURATION_OVERFLOW("timestamp(253402300799) + duration('100s') > timestamp(0)"),
 DYNAMIC_EQUALITY_TIMESTAMP_INT_COLLISION(
 "type(dyn_var) == int && dyn_var == 0 ? dyn_var != timestamp('1970-01-01T00:00:00Z') :"
Expand Down
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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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Aug 1, 2026
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Mark uninterpreted conversions with literals as approximate
#1155
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4 changes: 3 additions & 1 deletion
verifier/src/main/java/dev/cel/verifier/CelAstToZ3Translator.java

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Original file line numberDiff line numberDiff line change
Expand Up@@ -741,8 +741,10 @@ private TranslatedValue translateCall(CelExpr expr, CelAbstractSyntaxTree ast) {
 typeConstraints.add(ctx.mkNot(typeSystem.isUnknown(callRes)));
 typeConstraints.add(ctx.mkNot(typeSystem.isError(callRes)));

 boolean isDynamic = ast.getType(exprId).map(SimpleType.DYN::equals).orElse(true);
 BoolExpr isApprox = ctx.mkBool(!isDynamic);
 return TranslatedValue.propagateStrict(
 ctx, typeSystem, callRes, Optional.of(expr), ctx.mkTrue(), args);
 ctx, typeSystem, callRes, Optional.of(expr), isApprox, args);
 });
 }

Expand Down

3 changes: 2 additions & 1 deletion
verifier/src/main/java/dev/cel/verifier/CelZ3OperatorTranslator.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -594,7 +594,8 @@ private TranslatedValue translateEquality(
 // because X == X is a tautology (or propagates errors/unknowns exactly).
 if (z3Arg0.equals(z3Arg1)) {
 Expr<?> finalResult = typeSystem.propagateErrorAndUnknown(equalityExpr, z3Arg0);
 return TranslatedValue.create(finalResult, typeSystem, ctx.mkFalse());
 return TranslatedValue.create(
 finalResult, typeSystem, ctx.mkOr(arg0.isApproximate(), arg1.isApproximate()));
 }

 return TranslatedValue.propagateStrict(ctx, typeSystem, equalityExpr, arg0, arg1)
Expand Down

30 changes: 30 additions & 0 deletions
verifier/src/main/java/dev/cel/verifier/CelZ3TypeSystem.java

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Original file line numberDiff line numberDiff line change
Expand Up@@ -26,6 +26,7 @@
import com.microsoft.z3.DatatypeSort;
import com.microsoft.z3.Expr;
import com.microsoft.z3.FPExpr;
import com.microsoft.z3.FPNum;
import com.microsoft.z3.FuncDecl;
import com.microsoft.z3.IntExpr;
import com.microsoft.z3.SeqExpr;
Expand DownExpand Up@@ -280,6 +281,35 @@ Constructor optionalCons() {
 return optionalCons;
 }

 /**
 * Checks if the given CelValue expression represents a statically known primitive constant.
 *
 * <p>This is useful for determining whether an uninterpreted function's result should be treated
 * as an approximation. If the argument is a known constant, any resulting error is an
 * approximation (e.g., parsing a literal string). If it's a variable, the error is an exact
 * runtime failure.
 */
 public boolean isPrimitiveConstant(Expr<?> expr) {
 if (!expr.isApp()) {
 return false;
 }
 FuncDecl<?> decl = expr.getFuncDecl();
 if (decl.equals(stringCons.ConstructorDecl()) || decl.equals(bytesCons.ConstructorDecl())) {
 return expr.getArgs()[0].isString();
 } else if (decl.equals(intCons.ConstructorDecl())
 || decl.equals(uintCons.ConstructorDecl())
 || decl.equals(timestampCons.ConstructorDecl())
 || decl.equals(durationCons.ConstructorDecl())) {
 return expr.getArgs()[0].isNumeral();
 } else if (decl.equals(doubleCons.ConstructorDecl())) {
 return expr.getArgs()[0] instanceof FPNum;
 } else if (decl.equals(boolCons.ConstructorDecl())) {
 Expr<?> inner = expr.getArgs()[0];
 return inner.isTrue() || inner.isFalse();
 }
 return false;
 }

 /** Creates a CelValue containing a boolean. */
 public Expr<?> mkBool(boolean val) {
 return ctx.mkApp(boolCons.ConstructorDecl(), ctx.mkBool(val));
Expand Down

153 changes: 75 additions & 78 deletions
verifier/src/main/java/dev/cel/verifier/axioms/TypeConversionAxioms.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -19,11 +19,13 @@
import com.google.common.collect.ImmutableList;
import com.microsoft.z3.BoolExpr;
import com.microsoft.z3.Expr;
import com.microsoft.z3.FPExpr;
import com.microsoft.z3.FuncDecl;
import com.microsoft.z3.IntExpr;
import com.microsoft.z3.Sort;
import dev.cel.checker.CelStandardDeclarations.StandardFunction;
import dev.cel.checker.CelStandardDeclarations.StandardFunction.Overload.Conversions;
import dev.cel.common.types.SimpleType;
import java.util.Optional;

/** Axiomatization for CEL's type conversion functions. */
Expand All@@ -42,14 +44,12 @@ final class TypeConversionAxioms {
 return Optional.of(
 typeSystem.withRuntimeError(typeSystem.wrapInt(uintVal), outOfBounds));
 })
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.DOUBLE_TO_INT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DOUBLE_TO_INT64),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.DOUBLE_TO_INT64))
 .addOverloadTranslator(
 Conversions.STRING_TO_INT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_INT64),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_INT64))
 .addUnaryOverloadTranslator(
 Conversions.TIMESTAMP_TO_INT64.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) ->
Expand All@@ -69,79 +69,66 @@ final class TypeConversionAxioms {
 return Optional.of(
 typeSystem.withRuntimeError(typeSystem.wrapUint(intVal), outOfBounds));
 })
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.DOUBLE_TO_UINT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DOUBLE_TO_UINT64),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.DOUBLE_TO_UINT64))
 .addOverloadTranslator(
 Conversions.STRING_TO_UINT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_UINT64),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_UINT64))
 .build();

 private static final CelZ3FunctionAxiom DOUBLE_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.DOUBLE.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.DOUBLE_TO_DOUBLE.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.INT64_TO_DOUBLE.celOverloadDecl(),
 createUninterpretedConversion(Conversions.INT64_TO_DOUBLE),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.INT64_TO_DOUBLE))
 .addOverloadTranslator(
 Conversions.UINT64_TO_DOUBLE.celOverloadDecl(),
 createUninterpretedConversion(Conversions.UINT64_TO_DOUBLE),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.UINT64_TO_DOUBLE))
 .addOverloadTranslator(
 Conversions.STRING_TO_DOUBLE.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_DOUBLE),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_DOUBLE))
 .build();

 private static final CelZ3FunctionAxiom STRING_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.STRING.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.STRING_TO_STRING.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.INT64_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.INT64_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.INT64_TO_STRING))
 .addOverloadTranslator(
 Conversions.UINT64_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.UINT64_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.UINT64_TO_STRING))
 .addOverloadTranslator(
 Conversions.DOUBLE_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DOUBLE_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.DOUBLE_TO_STRING))
 .addOverloadTranslator(
 Conversions.BOOL_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.BOOL_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.BOOL_TO_STRING))
 .addOverloadTranslator(
 Conversions.BYTES_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.BYTES_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.BYTES_TO_STRING))
 .addOverloadTranslator(
 Conversions.TIMESTAMP_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.TIMESTAMP_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.TIMESTAMP_TO_STRING))
 .addOverloadTranslator(
 Conversions.DURATION_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DURATION_TO_STRING),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.DURATION_TO_STRING))
 .build();

 private static final CelZ3FunctionAxiom BYTES_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.BYTES.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.BYTES_TO_BYTES.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_BYTES.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_BYTES),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_BYTES))
 .build();

 private static final CelZ3FunctionAxiom DYN_AXIOM =
Expand All@@ -156,21 +143,19 @@ final class TypeConversionAxioms {
 .addUnaryOverloadTranslator(
 Conversions.DURATION_TO_DURATION.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_DURATION.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_DURATION),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_DURATION))
 .build();

 private static final CelZ3FunctionAxiom TIMESTAMP_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.TIMESTAMP.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.TIMESTAMP_TO_TIMESTAMP.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_TIMESTAMP.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_TIMESTAMP),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_TIMESTAMP))
 .addUnaryOverloadTranslator(
 Conversions.INT64_TO_TIMESTAMP.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> {
Expand All@@ -186,10 +171,9 @@ final class TypeConversionAxioms {
 .addUnaryOverloadTranslator(
 Conversions.BOOL_TO_BOOL.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_BOOL.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_BOOL),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_BOOL))
 .build();

 static final ImmutableList<CelZ3FunctionAxiom> ALL_AXIOMS =
Expand All@@ -204,64 +188,77 @@ final class TypeConversionAxioms {
 TIMESTAMP_AXIOM,
 BOOL_AXIOM);

 private static CelZ3FunctionAxiom.UnaryTranslator createUninterpretedConversion(
 Conversions conversion) {
 return (ctx, typeSystem, sink, arg) -> {
 private static CelZ3OverloadTranslator createUninterpretedConversion(Conversions conversion) {
 return (ctx, typeSystem, sink, unwrappedArgs, argApproximations) -> {
 Expr<?> arg = unwrappedArgs.get(0);
 BoolExpr baseApprox = argApproximations.get(0);

 FuncDecl<?> funcDecl =
 typeSystem.internFuncDecl(
 conversion.celOverloadDecl().overloadId(),
 new Sort[] {typeSystem.celValueSort()},
 typeSystem.celValueSort());
 Expr<?> res = ctx.mkApp(funcDecl, arg);

 BoolExpr isValid;
 switch (conversion.celOverloadDecl().resultType().kind()) {
 case INT:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isInt(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isInt(res),
 ctx.mkNot(typeSystem.checkIntOverflow(typeSystem.getInt(res))));
 ctx.mkNot(typeSystem.checkIntOverflow(typeSystem.getInt(res)))));
 break;
 case TIMESTAMP:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isTimestamp(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isTimestamp(res),
 ctx.mkNot(typeSystem.checkTimestampOverflow(typeSystem.getTimestamp(res))));
 ctx.mkNot(typeSystem.checkTimestampOverflow(typeSystem.getTimestamp(res)))));
 break;
 case DURATION:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isDuration(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isDuration(res),
 ctx.mkNot(typeSystem.checkDurationOverflow(typeSystem.getDuration(res))));
 ctx.mkNot(typeSystem.checkDurationOverflow(typeSystem.getDuration(res)))));
 break;
 case UINT:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isUint(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isUint(res),
 ctx.mkNot(typeSystem.checkUintOverflow(typeSystem.getUint(res))));
 ctx.mkNot(typeSystem.checkUintOverflow(typeSystem.getUint(res)))));
 break;
 case DOUBLE:
 isValid =
 ctx.mkAnd(
 typeSystem.isDouble(res), ctx.mkNot(ctx.mkFPIsNaN(typeSystem.getDouble(res))));
 sink.accept(ctx.mkOr(typeSystem.isDouble(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isDouble(res),
 ctx.mkNot(ctx.mkFPIsNaN((FPExpr) typeSystem.getDouble(res)))));
 break;
 case STRING:
isValid = typeSystem.isString(res);
sink.accept(ctx.mkOr(typeSystem.isString(res), typeSystem.isError(res)));
 break;
 case BYTES:
isValid = typeSystem.isBytes(res);
sink.accept(ctx.mkOr(typeSystem.isBytes(res), typeSystem.isError(res)));
 break;
 case BOOL:
isValid = typeSystem.isBool(res);
sink.accept(ctx.mkOr(typeSystem.isBool(res), typeSystem.isError(res)));
 break;
 default:
 throw new IllegalArgumentException(
 "Unsupported uninterpreted conversion result type: "
 + conversion.celOverloadDecl().resultType());
 }

 sink.accept(ctx.mkOr(isValid, typeSystem.isError(res)));
 return Optional.of(res);
 boolean isArgConstant = typeSystem.isPrimitiveConstant(arg);
 boolean isStringParseConversion =
 conversion.celOverloadDecl().parameterTypes().get(0).equals(SimpleType.STRING);

 BoolExpr finalApprox =
 (!isArgConstant && isStringParseConversion) ? baseApprox : ctx.mkTrue();

 return Optional.of(CelZ3OverloadResult.create(res, finalApprox));
 };
 }

Expand Down

17 changes: 9 additions & 8 deletions
verifier/src/test/java/dev/cel/verifier/CelVerifierZ3ImplTest.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -154,8 +154,6 @@ private enum IsSatisfiableTestCase {
 NULL_SATISFIABLE("unknown_var == null"),
 DYNAMIC_VAR_NUMERIC_EQUALITY("dyn_var == 1 && dyn_var == 1.0"),
 DYNAMIC_VAR_NOT_IN_LIST("dyn_var == 1.5 && !(dyn_var in dyn_list) && size(dyn_list) > 5"),
 TIMESTAMP_EQUALITY_TAUTOLOGY(
 "timestamp('2023-01-01T00:00:00Z') == timestamp('2023-01-01T00:00:00Z')"),
 CROSS_NUMERIC_EQUALITY_INT_DYN_EXACT("1 == request"),
 MACRO_LIMIT("dyn_list.all(x, x == 1)"),
 STRUCT_FIELD_MISSING_APPROXIMATE_SATISFIABLE("dyn_var.unknown_field"),
Expand DownExpand Up@@ -1353,12 +1351,10 @@ private enum IsAlwaysTrueViolationTestCase {
 "duration(string_var) == duration(string_var)",
 "Condition is not always true\\.",
 "Counterexample input:"),
 // TODO: Implement RFC 3339 spec in conversion
 TIMESTAMP_STRING_CONVERSION_VALID(
 "timestamp('2023-01-01T00:00:00Z') == timestamp('2023-01-01T00:00:00Z')",
 "Condition is not always true\\."),
 DURATION_STRING_CONVERSION_VALID(
 "duration('100s') == duration('100s')", "Condition is not always true\\."),
 UNINTERPRETED_CONVERSION_CAN_ERROR_BOOL_FROM_STRING(
 "bool(string_var) == bool(string_var)",
 "Condition is not always true\\.",
 "Counterexample input:"),
 ;

 final String expr;
Expand All@@ -1384,6 +1380,11 @@ public void isAlwaysTrue_violation_returnsFalse(
 }

 private enum IsInconclusiveTestCase {
 // TODO: Implement RFC 3339 spec in conversion
 TIMESTAMP_STRING_CONVERSION_VALID(
 "timestamp('2023-01-01T00:00:00Z') == timestamp('2023-01-01T00:00:00Z')"),
 DURATION_STRING_CONVERSION_VALID("duration('100s') == duration('100s')"),
 BOOL_STRING_UNINTERPRETED("bool('true') == true"),
 TIMESTAMP_ADD_DURATION_OVERFLOW("timestamp(253402300799) + duration('100s') > timestamp(0)"),
 DYNAMIC_EQUALITY_TIMESTAMP_INT_COLLISION(
 "type(dyn_var) == int && dyn_var == 0 ? dyn_var != timestamp('1970-01-01T00:00:00Z') :"
Expand Down
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode");
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

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 Merged

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merged 1 commit into

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Aug 1, 2026
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Mark uninterpreted conversions with literals as approximate
#1155
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4 changes: 3 additions & 1 deletion
verifier/src/main/java/dev/cel/verifier/CelAstToZ3Translator.java

View file


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Original file line numberDiff line numberDiff line change
Expand Up@@ -741,8 +741,10 @@ private TranslatedValue translateCall(CelExpr expr, CelAbstractSyntaxTree ast) {
 typeConstraints.add(ctx.mkNot(typeSystem.isUnknown(callRes)));
 typeConstraints.add(ctx.mkNot(typeSystem.isError(callRes)));

 boolean isDynamic = ast.getType(exprId).map(SimpleType.DYN::equals).orElse(true);
 BoolExpr isApprox = ctx.mkBool(!isDynamic);
 return TranslatedValue.propagateStrict(
 ctx, typeSystem, callRes, Optional.of(expr), ctx.mkTrue(), args);
 ctx, typeSystem, callRes, Optional.of(expr), isApprox, args);
 });
 }

Expand Down

3 changes: 2 additions & 1 deletion
verifier/src/main/java/dev/cel/verifier/CelZ3OperatorTranslator.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -594,7 +594,8 @@ private TranslatedValue translateEquality(
 // because X == X is a tautology (or propagates errors/unknowns exactly).
 if (z3Arg0.equals(z3Arg1)) {
 Expr<?> finalResult = typeSystem.propagateErrorAndUnknown(equalityExpr, z3Arg0);
 return TranslatedValue.create(finalResult, typeSystem, ctx.mkFalse());
 return TranslatedValue.create(
 finalResult, typeSystem, ctx.mkOr(arg0.isApproximate(), arg1.isApproximate()));
 }

 return TranslatedValue.propagateStrict(ctx, typeSystem, equalityExpr, arg0, arg1)
Expand Down

30 changes: 30 additions & 0 deletions
verifier/src/main/java/dev/cel/verifier/CelZ3TypeSystem.java

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -26,6 +26,7 @@
import com.microsoft.z3.DatatypeSort;
import com.microsoft.z3.Expr;
import com.microsoft.z3.FPExpr;
import com.microsoft.z3.FPNum;
import com.microsoft.z3.FuncDecl;
import com.microsoft.z3.IntExpr;
import com.microsoft.z3.SeqExpr;
Expand DownExpand Up@@ -280,6 +281,35 @@ Constructor optionalCons() {
 return optionalCons;
 }

 /**
 * Checks if the given CelValue expression represents a statically known primitive constant.
 *
 * <p>This is useful for determining whether an uninterpreted function's result should be treated
 * as an approximation. If the argument is a known constant, any resulting error is an
 * approximation (e.g., parsing a literal string). If it's a variable, the error is an exact
 * runtime failure.
 */
 public boolean isPrimitiveConstant(Expr<?> expr) {
 if (!expr.isApp()) {
 return false;
 }
 FuncDecl<?> decl = expr.getFuncDecl();
 if (decl.equals(stringCons.ConstructorDecl()) || decl.equals(bytesCons.ConstructorDecl())) {
 return expr.getArgs()[0].isString();
 } else if (decl.equals(intCons.ConstructorDecl())
 || decl.equals(uintCons.ConstructorDecl())
 || decl.equals(timestampCons.ConstructorDecl())
 || decl.equals(durationCons.ConstructorDecl())) {
 return expr.getArgs()[0].isNumeral();
 } else if (decl.equals(doubleCons.ConstructorDecl())) {
 return expr.getArgs()[0] instanceof FPNum;
 } else if (decl.equals(boolCons.ConstructorDecl())) {
 Expr<?> inner = expr.getArgs()[0];
 return inner.isTrue() || inner.isFalse();
 }
 return false;
 }

 /** Creates a CelValue containing a boolean. */
 public Expr<?> mkBool(boolean val) {
 return ctx.mkApp(boolCons.ConstructorDecl(), ctx.mkBool(val));
Expand Down

153 changes: 75 additions & 78 deletions
verifier/src/main/java/dev/cel/verifier/axioms/TypeConversionAxioms.java

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Original file line numberDiff line numberDiff line change
Expand Up@@ -19,11 +19,13 @@
import com.google.common.collect.ImmutableList;
import com.microsoft.z3.BoolExpr;
import com.microsoft.z3.Expr;
import com.microsoft.z3.FPExpr;
import com.microsoft.z3.FuncDecl;
import com.microsoft.z3.IntExpr;
import com.microsoft.z3.Sort;
import dev.cel.checker.CelStandardDeclarations.StandardFunction;
import dev.cel.checker.CelStandardDeclarations.StandardFunction.Overload.Conversions;
import dev.cel.common.types.SimpleType;
import java.util.Optional;

/** Axiomatization for CEL's type conversion functions. */
Expand All@@ -42,14 +44,12 @@ final class TypeConversionAxioms {
 return Optional.of(
 typeSystem.withRuntimeError(typeSystem.wrapInt(uintVal), outOfBounds));
 })
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.DOUBLE_TO_INT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DOUBLE_TO_INT64),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.DOUBLE_TO_INT64))
 .addOverloadTranslator(
 Conversions.STRING_TO_INT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_INT64),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_INT64))
 .addUnaryOverloadTranslator(
 Conversions.TIMESTAMP_TO_INT64.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) ->
Expand All@@ -69,79 +69,66 @@ final class TypeConversionAxioms {
 return Optional.of(
 typeSystem.withRuntimeError(typeSystem.wrapUint(intVal), outOfBounds));
 })
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.DOUBLE_TO_UINT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DOUBLE_TO_UINT64),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.DOUBLE_TO_UINT64))
 .addOverloadTranslator(
 Conversions.STRING_TO_UINT64.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_UINT64),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_UINT64))
 .build();

 private static final CelZ3FunctionAxiom DOUBLE_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.DOUBLE.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.DOUBLE_TO_DOUBLE.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.INT64_TO_DOUBLE.celOverloadDecl(),
 createUninterpretedConversion(Conversions.INT64_TO_DOUBLE),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.INT64_TO_DOUBLE))
 .addOverloadTranslator(
 Conversions.UINT64_TO_DOUBLE.celOverloadDecl(),
 createUninterpretedConversion(Conversions.UINT64_TO_DOUBLE),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.UINT64_TO_DOUBLE))
 .addOverloadTranslator(
 Conversions.STRING_TO_DOUBLE.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_DOUBLE),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_DOUBLE))
 .build();

 private static final CelZ3FunctionAxiom STRING_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.STRING.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.STRING_TO_STRING.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.INT64_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.INT64_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.INT64_TO_STRING))
 .addOverloadTranslator(
 Conversions.UINT64_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.UINT64_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.UINT64_TO_STRING))
 .addOverloadTranslator(
 Conversions.DOUBLE_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DOUBLE_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.DOUBLE_TO_STRING))
 .addOverloadTranslator(
 Conversions.BOOL_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.BOOL_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.BOOL_TO_STRING))
 .addOverloadTranslator(
 Conversions.BYTES_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.BYTES_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.BYTES_TO_STRING))
 .addOverloadTranslator(
 Conversions.TIMESTAMP_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.TIMESTAMP_TO_STRING),
 /* isApproximated= */ true)
 .addUnaryOverloadTranslator(
 createUninterpretedConversion(Conversions.TIMESTAMP_TO_STRING))
 .addOverloadTranslator(
 Conversions.DURATION_TO_STRING.celOverloadDecl(),
 createUninterpretedConversion(Conversions.DURATION_TO_STRING),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.DURATION_TO_STRING))
 .build();

 private static final CelZ3FunctionAxiom BYTES_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.BYTES.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.BYTES_TO_BYTES.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_BYTES.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_BYTES),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_BYTES))
 .build();

 private static final CelZ3FunctionAxiom DYN_AXIOM =
Expand All@@ -156,21 +143,19 @@ final class TypeConversionAxioms {
 .addUnaryOverloadTranslator(
 Conversions.DURATION_TO_DURATION.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_DURATION.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_DURATION),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_DURATION))
 .build();

 private static final CelZ3FunctionAxiom TIMESTAMP_AXIOM =
 CelZ3FunctionAxiom.newBuilder(StandardFunction.TIMESTAMP.functionDecl())
 .addUnaryOverloadTranslator(
 Conversions.TIMESTAMP_TO_TIMESTAMP.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_TIMESTAMP.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_TIMESTAMP),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_TIMESTAMP))
 .addUnaryOverloadTranslator(
 Conversions.INT64_TO_TIMESTAMP.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> {
Expand All@@ -186,10 +171,9 @@ final class TypeConversionAxioms {
 .addUnaryOverloadTranslator(
 Conversions.BOOL_TO_BOOL.celOverloadDecl(),
 (ctx, typeSystem, sink, arg) -> Optional.of(arg))
 .addUnaryOverloadTranslator(
 .addOverloadTranslator(
 Conversions.STRING_TO_BOOL.celOverloadDecl(),
 createUninterpretedConversion(Conversions.STRING_TO_BOOL),
 /* isApproximated= */ true)
 createUninterpretedConversion(Conversions.STRING_TO_BOOL))
 .build();

 static final ImmutableList<CelZ3FunctionAxiom> ALL_AXIOMS =
Expand All@@ -204,64 +188,77 @@ final class TypeConversionAxioms {
 TIMESTAMP_AXIOM,
 BOOL_AXIOM);

 private static CelZ3FunctionAxiom.UnaryTranslator createUninterpretedConversion(
 Conversions conversion) {
 return (ctx, typeSystem, sink, arg) -> {
 private static CelZ3OverloadTranslator createUninterpretedConversion(Conversions conversion) {
 return (ctx, typeSystem, sink, unwrappedArgs, argApproximations) -> {
 Expr<?> arg = unwrappedArgs.get(0);
 BoolExpr baseApprox = argApproximations.get(0);

 FuncDecl<?> funcDecl =
 typeSystem.internFuncDecl(
 conversion.celOverloadDecl().overloadId(),
 new Sort[] {typeSystem.celValueSort()},
 typeSystem.celValueSort());
 Expr<?> res = ctx.mkApp(funcDecl, arg);

 BoolExpr isValid;
 switch (conversion.celOverloadDecl().resultType().kind()) {
 case INT:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isInt(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isInt(res),
 ctx.mkNot(typeSystem.checkIntOverflow(typeSystem.getInt(res))));
 ctx.mkNot(typeSystem.checkIntOverflow(typeSystem.getInt(res)))));
 break;
 case TIMESTAMP:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isTimestamp(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isTimestamp(res),
 ctx.mkNot(typeSystem.checkTimestampOverflow(typeSystem.getTimestamp(res))));
 ctx.mkNot(typeSystem.checkTimestampOverflow(typeSystem.getTimestamp(res)))));
 break;
 case DURATION:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isDuration(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isDuration(res),
 ctx.mkNot(typeSystem.checkDurationOverflow(typeSystem.getDuration(res))));
 ctx.mkNot(typeSystem.checkDurationOverflow(typeSystem.getDuration(res)))));
 break;
 case UINT:
 isValid =
 ctx.mkAnd(
 sink.accept(ctx.mkOr(typeSystem.isUint(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isUint(res),
 ctx.mkNot(typeSystem.checkUintOverflow(typeSystem.getUint(res))));
 ctx.mkNot(typeSystem.checkUintOverflow(typeSystem.getUint(res)))));
 break;
 case DOUBLE:
 isValid =
 ctx.mkAnd(
 typeSystem.isDouble(res), ctx.mkNot(ctx.mkFPIsNaN(typeSystem.getDouble(res))));
 sink.accept(ctx.mkOr(typeSystem.isDouble(res), typeSystem.isError(res)));
 sink.accept(
 ctx.mkImplies(
 typeSystem.isDouble(res),
 ctx.mkNot(ctx.mkFPIsNaN((FPExpr) typeSystem.getDouble(res)))));
 break;
 case STRING:
isValid = typeSystem.isString(res);
sink.accept(ctx.mkOr(typeSystem.isString(res), typeSystem.isError(res)));
 break;
 case BYTES:
isValid = typeSystem.isBytes(res);
sink.accept(ctx.mkOr(typeSystem.isBytes(res), typeSystem.isError(res)));
 break;
 case BOOL:
isValid = typeSystem.isBool(res);
sink.accept(ctx.mkOr(typeSystem.isBool(res), typeSystem.isError(res)));
 break;
 default:
 throw new IllegalArgumentException(
 "Unsupported uninterpreted conversion result type: "
 + conversion.celOverloadDecl().resultType());
 }

 sink.accept(ctx.mkOr(isValid, typeSystem.isError(res)));
 return Optional.of(res);
 boolean isArgConstant = typeSystem.isPrimitiveConstant(arg);
 boolean isStringParseConversion =
 conversion.celOverloadDecl().parameterTypes().get(0).equals(SimpleType.STRING);

 BoolExpr finalApprox =
 (!isArgConstant && isStringParseConversion) ? baseApprox : ctx.mkTrue();

 return Optional.of(CelZ3OverloadResult.create(res, finalApprox));
 };
 }

Expand Down

17 changes: 9 additions & 8 deletions
verifier/src/test/java/dev/cel/verifier/CelVerifierZ3ImplTest.java

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Original file line numberDiff line numberDiff line change
Expand Up@@ -154,8 +154,6 @@ private enum IsSatisfiableTestCase {
 NULL_SATISFIABLE("unknown_var == null"),
 DYNAMIC_VAR_NUMERIC_EQUALITY("dyn_var == 1 && dyn_var == 1.0"),
 DYNAMIC_VAR_NOT_IN_LIST("dyn_var == 1.5 && !(dyn_var in dyn_list) && size(dyn_list) > 5"),
 TIMESTAMP_EQUALITY_TAUTOLOGY(
 "timestamp('2023-01-01T00:00:00Z') == timestamp('2023-01-01T00:00:00Z')"),
 CROSS_NUMERIC_EQUALITY_INT_DYN_EXACT("1 == request"),
 MACRO_LIMIT("dyn_list.all(x, x == 1)"),
 STRUCT_FIELD_MISSING_APPROXIMATE_SATISFIABLE("dyn_var.unknown_field"),
Expand DownExpand Up@@ -1353,12 +1351,10 @@ private enum IsAlwaysTrueViolationTestCase {
 "duration(string_var) == duration(string_var)",
 "Condition is not always true\\.",
 "Counterexample input:"),
 // TODO: Implement RFC 3339 spec in conversion
 TIMESTAMP_STRING_CONVERSION_VALID(
 "timestamp('2023-01-01T00:00:00Z') == timestamp('2023-01-01T00:00:00Z')",
 "Condition is not always true\\."),
 DURATION_STRING_CONVERSION_VALID(
 "duration('100s') == duration('100s')", "Condition is not always true\\."),
 UNINTERPRETED_CONVERSION_CAN_ERROR_BOOL_FROM_STRING(
 "bool(string_var) == bool(string_var)",
 "Condition is not always true\\.",
 "Counterexample input:"),
 ;

 final String expr;
Expand All@@ -1384,6 +1380,11 @@ public void isAlwaysTrue_violation_returnsFalse(
 }

 private enum IsInconclusiveTestCase {
 // TODO: Implement RFC 3339 spec in conversion
 TIMESTAMP_STRING_CONVERSION_VALID(
 "timestamp('2023-01-01T00:00:00Z') == timestamp('2023-01-01T00:00:00Z')"),
 DURATION_STRING_CONVERSION_VALID("duration('100s') == duration('100s')"),
 BOOL_STRING_UNINTERPRETED("bool('true') == true"),
 TIMESTAMP_ADD_DURATION_OVERFLOW("timestamp(253402300799) + duration('100s') > timestamp(0)"),
 DYNAMIC_EQUALITY_TIMESTAMP_INT_COLLISION(
 "type(dyn_var) == int && dyn_var == 0 ? dyn_var != timestamp('1970-01-01T00:00:00Z') :"
Expand Down
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