[PATCH] D70611: Reinstate MSan suppression of PR24578.

[Evgenii Stepanov via Phabricator via llvm-commits]

eugenis created this revision.
eugenis added a reviewer: vitalybuka.
Herald added a subscriber: hiraditya.
Herald added a project: LLVM.

Revert "Rollback of commit "Repress sanitization on User dtor.""

There is no point in keeping an active MSan error in the codebase.
PR24578 tracks the actual UB in LLVM code; this change enables testing
of LLVM with MSAN + -fsanitize-memory-use-after-dtor.

This reverts commit 21c1bc46aee2b69c2c48db8e961f0ce8394f21e1.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D70611

Files:
  llvm/include/llvm/Support/Compiler.h
  llvm/lib/IR/Metadata.cpp
  llvm/lib/IR/User.cpp


Index: llvm/lib/IR/User.cpp
===================================================================
--- llvm/lib/IR/User.cpp
+++ llvm/lib/IR/User.cpp
@@ -162,7 +162,9 @@
 //                         User operator delete Implementation
 //===----------------------------------------------------------------------===//
 
-void User::operator delete(void *Usr) {
+// Repress memory sanitization, due to use-after-destroy by operator
+// delete. Bug report 24578 identifies this issue.
+LLVM_NO_SANITIZE_MEMORY_ATTRIBUTE void User::operator delete(void *Usr) {
   // Hung off uses use a single Use* before the User, while other subclasses
   // use a Use[] allocated prior to the user.
   User *Obj = static_cast<User *>(Usr);
Index: llvm/lib/IR/Metadata.cpp
===================================================================
--- llvm/lib/IR/Metadata.cpp
+++ llvm/lib/IR/Metadata.cpp
@@ -489,7 +489,9 @@
   return Ptr;
 }
 
-void MDNode::operator delete(void *Mem) {
+// Repress memory sanitization, due to use-after-destroy by operator
+// delete. Bug report 24578 identifies this issue.
+LLVM_NO_SANITIZE_MEMORY_ATTRIBUTE void MDNode::operator delete(void *Mem) {
   MDNode *N = static_cast<MDNode *>(Mem);
   size_t OpSize = N->NumOperands * sizeof(MDOperand);
   OpSize = alignTo(OpSize, alignof(uint64_t));
Index: llvm/include/llvm/Support/Compiler.h
===================================================================
--- llvm/include/llvm/Support/Compiler.h
+++ llvm/include/llvm/Support/Compiler.h
@@ -406,10 +406,12 @@
 #if __has_feature(memory_sanitizer)
 # define LLVM_MEMORY_SANITIZER_BUILD 1
 # include <sanitizer/msan_interface.h>
+# define LLVM_NO_SANITIZE_MEMORY_ATTRIBUTE __attribute__((no_sanitize_memory))
 #else
 # define LLVM_MEMORY_SANITIZER_BUILD 0
 # define __msan_allocated_memory(p, size)
 # define __msan_unpoison(p, size)
+# define LLVM_NO_SANITIZE_MEMORY_ATTRIBUTE
 #endif
 
 /// \macro LLVM_ADDRESS_SANITIZER_BUILD


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