[generator] Fix reserved keywords binary search (#977)

Context: 7068f4b
Context: https://docs.microsoft.com/en-us/dotnet/core/extensions/performing-culture-insensitive-string-operations-in-arrays
Commit 7068f4b enabled string code analyzers, because in e.g. the
`sr` locale, `"Ljava".StartsWith("L")` would be *false*, because `Lj`
was a language-specific digraph, and "special-cased". For intended
behavior, we need to use `.StartsWith("L", StringComparison.Ordinal)`.
There is a ["similar yet different" problem][0] with `Array.Sort()`
and `Array.BinarySearch()` and string arrays: a locale-specific
comparison is performed by default:
var reserved_keywords = new [] {
"as", "catch", "char", "checked", "class", "const",
};
var index = Array.BinarySearch (reserved_keywords, "checked");
The *expectation* is that `index` is 3. In the `cs-CZ` locale, "ch"
is a digraph, and `index` is -7, i.e. was not found.
There is currently no Code Analysis check for this scenario.
Review all `Array.Sort()` and `Array.BinarySearch()` invocations so
that an appropriate `IComparer` instance is provided. This allows
e.g. `checked` to be properly `@escaped` when created a binding in a
machine with a `cs-CZ` locale.
[0]: https://docs.microsoft.com/en-us/dotnet/core/extensions/performing-culture-insensitive-string-operations-in-arrays

Author: simonrozsival

tests/generator-Tests/Unit-Tests/CodeGenerationOptionsTests.cs

@@ -1,4 +1,5 @@
-usingSystem;
+usingSystem.Collections.Generic;
+usingSystem.Linq;
 usingMonoDroid.Generation;
 usingNUnit.Framework;
 
@@ -79,5 +80,17 @@ public void GetTypeReferenceName_Nullable ()
 
 Assert.AreEqual("uint",opt.GetTypeReferenceName(primitive_uint));
 }
+
+[Test,TestCaseSource(nameof(ReservedKeywords))]
+[SetCulture("cs-CZ")]
+publicvoidGetSafeIdentifierCultureInvariant(stringkeyword)
+{
+varopt=newCodeGenerationOptions();
+
+Assert.AreEqual($"{keyword}_",opt.GetSafeIdentifier(keyword));
+}
+
+privatestaticIEnumerable<TestCaseData>ReservedKeywords
+=>TypeNameUtilities.reserved_keywords.Select(keyword =>newTestCaseData(keyword));
 }
 }

tests/generator-Tests/Unit-Tests/TypeNameUtilitiesTests.cs

@@ -1,4 +1,5 @@
-usingSystem;
+usingSystem.Collections.Generic;
+usingSystem.Linq;
 usingMonoDroid.Generation;
 usingNUnit.Framework;
 
@@ -19,5 +20,17 @@ public void MangleName ()
 Assert.AreEqual("byte_var",TypeNameUtilities.MangleName("byte_var"));
 Assert.AreEqual("foo",TypeNameUtilities.MangleName("foo"));
 }
+
+[Test,TestCaseSource(nameof(ReservedKeywords))]
+[SetCulture("cs-CZ")]
+publicvoidMangleNameCutlureInvariant(stringkeyword)
+{
+Assert.AreEqual($"@{keyword}",TypeNameUtilities.MangleName(keyword));
+}
+
+privatestaticIEnumerable<TestCaseData>ReservedKeywords
+=>TypeNameUtilities.reserved_keywords
+.Where(keyword =>keyword!="event")// "event" is a special case which is mapped to "e" instead of "@event"
+.Select(keyword =>newTestCaseData(keyword));
 }
 }

tools/generator/CodeGenerationOptions.cs

@@ -267,7 +267,7 @@ public string GetSafeIdentifier (string name)
 // (ReturnValue.ToNative() takes an argument which could be either an expression or mere symbol.)
 if(name[name.Length-1]!=')'&&!name.Contains('.')&&!name.StartsWith("@",StringComparison.Ordinal)){
 if(!IdentifierValidator.IsValidIdentifier(name)||
-Array.BinarySearch(TypeNameUtilities.reserved_keywords,name)>=0){
+Array.BinarySearch(TypeNameUtilities.reserved_keywords,name,StringComparer.Ordinal)>=0){
 name=name+"_";
 }
 }

tools/generator/Utilities/TypeNameUtilities.cs

@@ -80,8 +80,8 @@ public static string MangleName (string name)
 {
 if(name=="event")
 return"e";
-
-if(Array.BinarySearch(reserved_keywords,name)>=0)
+
+if(Array.BinarySearch(reserved_keywords,name,StringComparer.Ordinal)>=0)
 return"@"+name;
 
 returnname;