[Clang][CodeGen] Emit !alloc_token for new expressions (#162099)

For new expressions, the allocated type is syntactically known and we
can trivially emit the !alloc_token metadata. A subsequent change will
wire up the AllocToken pass and introduce appropriate tests.

---

This change is part of the following series:
  1. https://github.com/llvm/llvm-project/pull/160131
  2. https://github.com/llvm/llvm-project/pull/156838
  3. https://github.com/llvm/llvm-project/pull/162098
  4. https://github.com/llvm/llvm-project/pull/162099
  5. https://github.com/llvm/llvm-project/pull/156839
  6. https://github.com/llvm/llvm-project/pull/156840
  7. https://github.com/llvm/llvm-project/pull/156841
  8. https://github.com/llvm/llvm-project/pull/156842

1 files changed, 17 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index 9f30287b68c7..a071e801b91e 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -1272,6 +1272,23 @@ void CodeGenFunction::EmitBoundsCheckImpl(const Expr *E, llvm::Value *Bound,
   EmitCheck(std::make_pair(Check, CheckKind), CheckHandler, StaticData, Index);
 }
 
+void CodeGenFunction::EmitAllocToken(llvm::CallBase *CB, QualType AllocType) {
+  assert(SanOpts.has(SanitizerKind::AllocToken) &&
+         "Only needed with -fsanitize=alloc-token");
+
+  PrintingPolicy Policy(CGM.getContext().getLangOpts());
+  Policy.SuppressTagKeyword = true;
+  Policy.FullyQualifiedName = true;
+  SmallString<64> TypeName;
+  llvm::raw_svector_ostream TypeNameOS(TypeName);
+  AllocType.getCanonicalType().print(TypeNameOS, Policy);
+  auto *TypeMDS = llvm::MDString::get(CGM.getLLVMContext(), TypeNameOS.str());
+
+  // Format: !{<type-name>}
+  auto *MDN = llvm::MDNode::get(CGM.getLLVMContext(), {TypeMDS});
+  CB->setMetadata(llvm::LLVMContext::MD_alloc_token, MDN);
+}
+
 CodeGenFunction::ComplexPairTy CodeGenFunction::
 EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
                          bool isInc, bool isPre) {