[clang] [Clang] Implement labelled type filtering for overflow/truncation sanitizers w/ SSCLs (PR #107332)

[Justin Stitt via cfe-commits]

================
@@ -831,6 +831,28 @@ ASTContext::getCanonicalTemplateTemplateParmDecl(
   return CanonTTP;
 }
 
+/// Check if a type can have its sanitizer instrumentation elided.
+/// Determine this by its presence in a SCL alongside its specified categories.
+/// For example:
+/// ignorelist.txt>
+/// [{unsigned-integer-overflow,signed-integer-overflow}]
+/// type:*=no_sanitize
+/// type:size_t=sanitize
+/// <ignorelist.txt
+/// Supplying the above ignorelist.txt will disable overflow sanitizer
+/// instrumentation for all types except "size_t".
+bool ASTContext::isTypeIgnoredBySanitizer(const SanitizerMask &Mask,
+                                          const QualType &Ty) const {
+  bool sanitizeType =
+      NoSanitizeL->containsType(Mask, Ty.getAsString(), "sanitize");
+
+  bool noSanitizeType =
----------------
JustinStitt wrote:

@vitalybuka 
> I tried insert "getCanonicalType()" and none of tests of this patch failed.

TEST 'Clang :: CodeGen/ubsan-type-ignorelist-category.test' FAILED with this diff:

```diff
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 480233894995..d66533d8a3d7 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -843,7 +843,8 @@ ASTContext::getCanonicalTemplateTemplateParmDecl(
 /// instrumentation for all types except "size_t".
 bool ASTContext::isTypeIgnoredBySanitizer(const SanitizerMask &Mask,
                                           const QualType &Ty) const {
-  std::string TyName = Ty.getUnqualifiedType().getAsString(getPrintingPolicy());
+  std::string TyName = Ty.getCanonicalType().getUnqualifiedType().getAsString(
+      getPrintingPolicy());
 
   return (NoSanitizeL->containsType(Mask, TyName) ||
           NoSanitizeL->containsType(Mask, TyName, "no_sanitize")) &&

```

log: https://gist.github.com/JustinStitt/bb3151fe54290966babcc1a9e78c8769

https://github.com/llvm/llvm-project/pull/107332