[Clang][CodeGen] Introduce the AllocToken SanitizerKind (#162098)

Introduce the "alloc-token" sanitizer kind, in preparation of wiring it up. Currently this is a no-op, and any attempt to enable it will result in failure: clang: error: unsupported option '-fsanitize=alloc-token' for target 'x86_64-unknown-linux-gnu' In this step we can already wire up the `sanitize_alloc_token` IR attribute where the instrumentation is enabled. Subsequent changes will complete wiring up the AllocToken pass. --- This change is part of the following series: 1. #160131 2. #156838 3. #162098 4. #162099 5. #156839 6. #156840 7. #156841 8. #156842

Author: melver

clang/include/clang/Basic/Sanitizers.def

@@ -195,6 +195,9 @@ SANITIZER_GROUP("bounds", Bounds, ArrayBounds | LocalBounds)
 // Scudo hardened allocator
 SANITIZER("scudo", Scudo)
 
+// AllocToken
+SANITIZER("alloc-token", AllocToken)
+
 // Magic group, containing all sanitizers. For example, "-fno-sanitize=all"
 // can be used to disable all the sanitizers.
 SANITIZER_GROUP("all", All, ~SanitizerMask())

clang/lib/CodeGen/CodeGenFunction.cpp

@@ -846,6 +846,8 @@ void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy,
  Fn->addFnAttr(llvm::Attribute::SanitizeNumericalStability);
  if (SanOpts.hasOneOf(SanitizerKind::Memory | SanitizerKind::KernelMemory))
  Fn->addFnAttr(llvm::Attribute::SanitizeMemory);
+ if (SanOpts.has(SanitizerKind::AllocToken))
+ Fn->addFnAttr(llvm::Attribute::SanitizeAllocToken);
  }
  if (SanOpts.has(SanitizerKind::SafeStack))
  Fn->addFnAttr(llvm::Attribute::SafeStack);