Add sanitizer-specific GlobalValue attributes.

Plan is the migrate the global variable metadata for sanitizers, that's
currently carried around generally in the 'llvm.asan.globals' section,
onto the global variable itself.

This patch adds the attribute and plumbs it through the LLVM IR and
bitcode formats, but is a no-op other than that so far.

Reviewed By: vitalybuka, kstoimenov

Differential Revision: https://reviews.llvm.org/D126100

1 files changed, 19 insertions, 0 deletions

diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index 9dd2b128..cd253c1 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -3441,6 +3441,19 @@ static void inferDSOLocal(GlobalValue *GV) {
     GV->setDSOLocal(true);
 }
 
+GlobalValue::SanitizerMetadata deserializeSanitizerMetadata(unsigned V) {
+  GlobalValue::SanitizerMetadata Meta;
+  if (V & (1 << 0))
+    Meta.NoAddress = true;
+  if (V & (1 << 1))
+    Meta.NoHWAddress = true;
+  if (V & (1 << 2))
+    Meta.NoMemtag = true;
+  if (V & (1 << 3))
+    Meta.IsDynInit = true;
+  return Meta;
+}
+
 Error BitcodeReader::parseGlobalVarRecord(ArrayRef<uint64_t> Record) {
   // v1: [pointer type, isconst, initid, linkage, alignment, section,
   // visibility, threadlocal, unnamed_addr, externally_initialized,
@@ -3544,6 +3557,12 @@ Error BitcodeReader::parseGlobalVarRecord(ArrayRef<uint64_t> Record) {
   if (Record.size() > 15)
     NewGV->setPartition(StringRef(Strtab.data() + Record[14], Record[15]));
 
+  if (Record.size() > 16 && Record[16] != UINT_MAX) {
+    llvm::GlobalValue::SanitizerMetadata Meta =
+        deserializeSanitizerMetadata(Record[16]);
+    NewGV->setSanitizerMetadata(Meta);
+  }
+
   return Error::success();
 }