Add CFI integer types normalization

This commit adds a new option (i.e.,
`-fsanitize-cfi-icall-normalize-integers`) for normalizing integer types
as vendor extended types for cross-language LLVM CFI/KCFI support with
other languages that can't represent and encode C/C++ integer types.

Specifically, integer types are encoded as their defined representations
(e.g., 8-bit signed integer, 16-bit signed integer, 32-bit signed
integer, ...) for compatibility with languages that define
explicitly-sized integer types (e.g., i8, i16, i32, ..., in Rust).

``-fsanitize-cfi-icall-normalize-integers`` is compatible with
``-fsanitize-cfi-icall-generalize-pointers``.

This helps with providing cross-language CFI support with the Rust
compiler and is an alternative solution for the issue described and
alternatives proposed in the RFC
https://github.com/rust-lang/rfcs/pull/3296.

For more information about LLVM CFI/KCFI and cross-language LLVM
CFI/KCFI support for the Rust compiler, see the design document in the
tracking issue https://github.com/rust-lang/rust/issues/89653.

Relands b1e9ab7438a098a18fecda88fc87ef4ccadfcf1e with fixes.

Reviewed By: pcc, samitolvanen

Differential Revision: https://reviews.llvm.org/D139395

1 files changed, 11 insertions, 2 deletions

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 0f93c3319435..71ec83143535 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -1731,7 +1731,11 @@ llvm::ConstantInt *CodeGenModule::CreateKCFITypeId(QualType T) {
 
   std::string OutName;
   llvm::raw_string_ostream Out(OutName);
-  getCXXABI().getMangleContext().mangleTypeName(T, Out);
+  getCXXABI().getMangleContext().mangleTypeName(
+      T, Out, getCodeGenOpts().SanitizeCfiICallNormalizeIntegers);
+
+  if (getCodeGenOpts().SanitizeCfiICallNormalizeIntegers)
+    Out << ".normalized";
 
   return llvm::ConstantInt::get(Int32Ty,
                                 static_cast<uint32_t>(llvm::xxHash64(OutName)));
@@ -6949,7 +6953,12 @@ CodeGenModule::CreateMetadataIdentifierImpl(QualType T, MetadataTypeMap &Map,
   if (isExternallyVisible(T->getLinkage())) {
     std::string OutName;
     llvm::raw_string_ostream Out(OutName);
-    getCXXABI().getMangleContext().mangleTypeName(T, Out);
+    getCXXABI().getMangleContext().mangleTypeName(
+        T, Out, getCodeGenOpts().SanitizeCfiICallNormalizeIntegers);
+
+    if (getCodeGenOpts().SanitizeCfiICallNormalizeIntegers)
+      Out << ".normalized";
+
     Out << Suffix;
 
     InternalId = llvm::MDString::get(getLLVMContext(), Out.str());