Rollup merge of #132702 - 1c3t3a:issue-132615, r=rcvalle

CFI: Append debug location to CFI blocks
Currently we're not appending debug locations to the inserted CFI blocks. This shows up in #132615 and #100783. This change fixes that by passing down the debug location to the CFI type-test generation and appending it to the blocks.
Credits also belong to `@jakos-sec` who worked with me on this.

Author: matthiaskrgr

compiler/rustc_codegen_gcc/src/debuginfo.rs

@@ -52,6 +52,10 @@ impl<'a, 'gcc, 'tcx> DebugInfoBuilderMethods for Builder<'a, 'gcc, 'tcx> {
 fnclear_dbg_loc(&mutself){
 self.location = None;
 }
+
+fnget_dbg_loc(&self) -> Option<Self::DILocation>{
+self.location
+}
 }
 
 /// Generate the `debug_context` in an MIR Body.

compiler/rustc_codegen_llvm/src/builder.rs

@@ -1574,6 +1574,7 @@ impl<'a, 'll, 'tcx> Builder<'a, 'll, 'tcx> {
  cfi::typeid_for_fnabi(self.tcx, fn_abi, options)
 };
 let typeid_metadata = self.cx.typeid_metadata(typeid).unwrap();
+let dbg_loc = self.get_dbg_loc();
 
 // Test whether the function pointer is associated with the type identifier.
 let cond = self.type_test(llfn, typeid_metadata);
@@ -1582,10 +1583,16 @@ impl<'a, 'll, 'tcx> Builder<'a, 'll, 'tcx> {
 self.cond_br(cond, bb_pass, bb_fail);
 
 self.switch_to_block(bb_fail);
+ifletSome(dbg_loc) = dbg_loc {
+self.set_dbg_loc(dbg_loc);
+}
 self.abort();
 self.unreachable();
 
 self.switch_to_block(bb_pass);
+ifletSome(dbg_loc) = dbg_loc {
+self.set_dbg_loc(dbg_loc);
+}
 }
 }
 

compiler/rustc_codegen_llvm/src/debuginfo/mod.rs

@@ -206,6 +206,10 @@ impl<'ll> DebugInfoBuilderMethods for Builder<'_, 'll, '_> {
 }
 }
 
+fnget_dbg_loc(&self) -> Option<&'llDILocation>{
+unsafe{ llvm::LLVMGetCurrentDebugLocation2(self.llbuilder)}
+}
+
 fninsert_reference_to_gdb_debug_scripts_section_global(&mutself){
  gdb::insert_reference_to_gdb_debug_scripts_section_global(self)
 }

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -1063,6 +1063,7 @@ unsafe extern "C" {
 
 // Metadata
 pubfnLLVMSetCurrentDebugLocation2<'a>(Builder:&Builder<'a>,Loc:*constMetadata);
+pubfnLLVMGetCurrentDebugLocation2<'a>(Builder:&Builder<'a>) -> Option<&'aMetadata>;
 
 // Terminators
 pubfnLLVMBuildRetVoid<'a>(B:&Builder<'a>) -> &'aValue;

compiler/rustc_codegen_ssa/src/traits/debuginfo.rs

@@ -81,6 +81,7 @@ pub trait DebugInfoBuilderMethods: BackendTypes {
 );
 fnset_dbg_loc(&mutself,dbg_loc:Self::DILocation);
 fnclear_dbg_loc(&mutself);
+fnget_dbg_loc(&self) -> Option<Self::DILocation>;
 fninsert_reference_to_gdb_debug_scripts_section_global(&mutself);
 fnset_var_name(&mutself,value:Self::Value,name:&str);
 }

tests/codegen/sanitizer/cfi/dbg-location-on-cfi-blocks.rs

@@ -0,0 +1,19 @@
+// Verifies that the parent block's debug information are assigned to the inserted cfi block.
+//
+//@ needs-sanitizer-cfi
+//@ compile-flags: -Clto -Cno-prepopulate-passes -Copt-level=0 -Zsanitizer=cfi -Ctarget-feature=-crt-static -Cdebuginfo=1
+
+#![crate_type = "lib"]
+
+pubfnfoo(f:fn(i32) -> i32,arg:i32) -> i32{
+// CHECK-LABEL: define{{.*}}foo{{.*}}!dbg !{{[0-9]+}} !type !{{[0-9]+}} !type !{{[0-9]+}} !type !{{[0-9]+}} !type !{{[0-9]+}}
+// CHECK: start:
+// CHECK: [[TT:%.+]] = call i1 @llvm.type.test(ptr {{%f|%0}}, metadata !"{{[[:print:]]+}}"), !dbg !{{[0-9]+}}
+// CHECK-NEXT: br i1 [[TT]], label %type_test.pass, label %type_test.fail, !dbg !{{[0-9]+}}
+// CHECK: type_test.pass: ; preds = %start
+// CHECK-NEXT: {{%.+}} = call i32 %f(i32{{.*}} %arg), !dbg !{{[0-9]+}}
+// CHECK: type_test.fail: ; preds = %start
+// CHECK-NEXT: call void @llvm.trap(), !dbg !{{[0-9]+}}
+// CHECK-NEXT: unreachable, !dbg !{{[0-9]+}}
+f(arg)
+}