[compiler-rt] beb3d48 - [ORC-RT] Fix objc selector corruption

[Ben Langmuir via llvm-commits]

Author: Ben Langmuir
Date: 2021-10-27T16:02:52-07:00
New Revision: beb3d48262bc541755d2f829b83b5f1e26d6d0b1

URL: https://github.com/llvm/llvm-project/commit/beb3d48262bc541755d2f829b83b5f1e26d6d0b1
DIFF: https://github.com/llvm/llvm-project/commit/beb3d48262bc541755d2f829b83b5f1e26d6d0b1.diff

LOG: [ORC-RT] Fix objc selector corruption

We were writing a pointer to a selector string into the contents of a
string instead of overwriting the pointer to the string, leading to
corruption. This was causing non-deterministic failures of the
'trivial-objc-methods' test case.

Differential Revision: https://reviews.llvm.org/D112671

Added: 
    

Modified: 
    compiler-rt/lib/orc/macho_platform.cpp

Removed: 
    


################################################################################
diff  --git a/compiler-rt/lib/orc/macho_platform.cpp b/compiler-rt/lib/orc/macho_platform.cpp
index fac9918da5893..e25b2a9568180 100644
--- a/compiler-rt/lib/orc/macho_platform.cpp
+++ b/compiler-rt/lib/orc/macho_platform.cpp
@@ -112,10 +112,10 @@ Error registerObjCSelectors(
     if (auto Err = validatePointerSectionExtent("__objc_selrefs", ObjCSelRefs))
       return Err;
 
-    for (uintptr_t SelEntry : ObjCSelRefs.toSpan<uintptr_t>()) {
+    for (uintptr_t &SelEntry : ObjCSelRefs.toSpan<uintptr_t>()) {
       const char *SelName = reinterpret_cast<const char *>(SelEntry);
       auto Sel = sel_registerName(SelName);
-      *reinterpret_cast<SEL *>(SelEntry) = Sel;
+      *reinterpret_cast<SEL *>(&SelEntry) = Sel;
     }
   }