[sanitizer][NFCI] Add 'SanitizerAnnotateDebugInfo' (#139965)

This generalizes the debug info annotation code from https://github.com/llvm/llvm-project/pull/139149 and moves it into a helper function, SanitizerAnnotateDebugInfo().

Future work can use 'ApplyDebugLocation ApplyTrapDI(*this, SanitizerAnnotateDebugInfo(Ordinal));' to add annotations to additional checks.

clang/lib/CodeGen/CGExpr.cpp

diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index ec01c87..37a5678 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -1226,16 +1226,8 @@
 
   SanitizerScope SanScope(this);
 
-  llvm::DILocation *CheckDI = Builder.getCurrentDebugLocation();
   auto CheckKind = SanitizerKind::SO_ArrayBounds;
-  // TODO: deprecate ClArrayBoundsPseudoFn
-  if ((ClArrayBoundsPseudoFn ||
-       CGM.getCodeGenOpts().SanitizeAnnotateDebugInfo.has(CheckKind)) &&
-      CheckDI) {
-    CheckDI = getDebugInfo()->CreateSyntheticInlineAt(
-        Builder.getCurrentDebugLocation(), "__ubsan_check_array_bounds");
-  }
-  ApplyDebugLocation ApplyTrapDI(*this, CheckDI);
+  ApplyDebugLocation ApplyTrapDI(*this, SanitizerAnnotateDebugInfo(CheckKind));
 
   bool IndexSigned = IndexType->isSignedIntegerOrEnumerationType();
   llvm::Value *IndexVal = Builder.CreateIntCast(Index, SizeTy, IndexSigned);
@@ -1252,6 +1244,35 @@
             StaticData, Index);
 }
 
+llvm::DILocation *CodeGenFunction::SanitizerAnnotateDebugInfo(
+    SanitizerKind::SanitizerOrdinal CheckKindOrdinal) {
+  std::string Label;
+  switch (CheckKindOrdinal) {
+#define SANITIZER(NAME, ID)                                                    \
+  case SanitizerKind::SO_##ID:                                                 \
+    Label = "__ubsan_check_" NAME;                                             \
+    break;
+#include "clang/Basic/Sanitizers.def"
+  default:
+    llvm_unreachable("unexpected sanitizer kind");
+  }
+
+  // Sanitize label
+  for (unsigned int i = 0; i < Label.length(); i++)
+    if (!std::isalpha(Label[i]))
+      Label[i] = '_';
+
+  llvm::DILocation *CheckDI = Builder.getCurrentDebugLocation();
+  // TODO: deprecate ClArrayBoundsPseudoFn
+  if (((ClArrayBoundsPseudoFn &&
+        CheckKindOrdinal == SanitizerKind::SO_ArrayBounds) ||
+       CGM.getCodeGenOpts().SanitizeAnnotateDebugInfo.has(CheckKindOrdinal)) &&
+      CheckDI)
+    CheckDI = getDebugInfo()->CreateSyntheticInlineAt(CheckDI, Label);
+
+  return CheckDI;
+}
+
 CodeGenFunction::ComplexPairTy CodeGenFunction::
 EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
                          bool isInc, bool isPre) {

clang/lib/CodeGen/CodeGenFunction.h

diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index fa4ceaf..7104303 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -2816,6 +2816,11 @@
   void emitStoresForInitAfterBZero(llvm::Constant *Init, Address Loc,
                                    bool isVolatile, bool IsAutoInit);
 
+  /// Returns debug info, with additional annotation if enabled by
+  /// CGM.getCodeGenOpts().SanitizeAnnotateDebugInfo[CheckKindOrdinal].
+  llvm::DILocation *
+  SanitizerAnnotateDebugInfo(SanitizerKind::SanitizerOrdinal CheckKindOrdinal);
+
 public:
   // Captures all the allocas created during the scope of its RAII object.
   struct AllocaTrackerRAII {