[llvm] [ASan] Add metadata to renamed instructions so ASan doesn't use the i… (PR #119387)

[via llvm-commits]

https://github.com/gbMattN updated https://github.com/llvm/llvm-project/pull/119387

>From 8781ff2355750ae61d140620b1f6862537de07e3 Mon Sep 17 00:00:00 2001
From: gbMattN <matthew.nagy at sony.com>
Date: Tue, 10 Dec 2024 15:01:37 +0000
Subject: [PATCH] [ASan] Add metadata to renamed instructions so ASan doesn't
 use the incorrect name

---
 llvm/lib/IR/ValueSymbolTable.cpp                         | 8 ++++++++
 llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp | 7 ++++++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/llvm/lib/IR/ValueSymbolTable.cpp b/llvm/lib/IR/ValueSymbolTable.cpp
index a020acf22a96c5..81bb3f3c5a5e35 100644
--- a/llvm/lib/IR/ValueSymbolTable.cpp
+++ b/llvm/lib/IR/ValueSymbolTable.cpp
@@ -123,6 +123,14 @@ ValueName *ValueSymbolTable::createValueName(StringRef Name, Value *V) {
   }
 
   // Otherwise, there is a naming conflict.  Rename this value.
+  // If we are renaming an instruction, ASan needs to know for it to serialize
+  // properly
+  if (auto *I = dyn_cast<Instruction>(V)) {
+    MDString *trueNameMetadata = MDString::get(V->getContext(), Name);
+    llvm::MDTuple *tuple =
+        llvm::MDTuple::get(V->getContext(), trueNameMetadata);
+    I->setMetadata("OriginalName", tuple);
+  }
   SmallString<256> UniqueName(Name.begin(), Name.end());
   return makeUniqueName(V, UniqueName);
 }
diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index cb84588318496c..c696cc38167cd4 100644
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -3430,7 +3430,12 @@ void FunctionStackPoisoner::processStaticAllocas() {
   SmallVector<ASanStackVariableDescription, 16> SVD;
   SVD.reserve(AllocaVec.size());
   for (AllocaInst *AI : AllocaVec) {
-    ASanStackVariableDescription D = {AI->getName().data(),
+    std::string Name = AI->getName().data();
+    if (AI->hasMetadata("OriginalName")) {
+      MDTuple *tuple = dyn_cast<MDTuple>(AI->getMetadata("OriginalName"));
+      Name = dyn_cast<MDString>(tuple->getOperand(0))->getString();
+    }
+    ASanStackVariableDescription D = {Name.c_str(),
                                       ASan.getAllocaSizeInBytes(*AI),
                                       0,
                                       AI->getAlign().value(),