[PATCH] D138095: [asan] Keep Itanium mangled names in global metadata

[Fangrui Song via Phabricator via llvm-commits]

MaskRay added a comment.

The reverse of the combined commits is the following. Any chance you found the wrong culprit?

  diff --git a/compiler-rt/lib/asan/asan_globals.cpp b/compiler-rt/lib/asan/asan_globals.cpp
  index 2b4a9e01c8a3..b780128c9adb 100644
  --- a/compiler-rt/lib/asan/asan_globals.cpp
  +++ b/compiler-rt/lib/asan/asan_globals.cpp
  @@ -151,4 +151,4 @@ static void CheckODRViolationViaIndicator(const Global *g) {
           !IsODRViolationSuppressed(g->name))
  -      ReportODRViolation(g, FindRegistrationSite(g), l->g,
  -                         FindRegistrationSite(l->g));
  +      ReportODRViolation(g, FindRegistrationSite(g),
  +                         l->g, FindRegistrationSite(l->g));
     }
  diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cpp
  index d505d96bd653..b223f6cd01e3 100644
  --- a/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cpp
  +++ b/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cpp
  @@ -51,13 +51,8 @@ const char *DemangleCXXABI(const char *name) {
     // own demangler (libc++abi's implementation could be adapted so that
  -  // it does not allocate). For now, we just call it anyway, and use
  -  // InternalAlloc to prevent lsan error.
  -  if (&__cxxabiv1::__cxa_demangle) {
  -    if (char *demangled_name = __cxxabiv1::__cxa_demangle(name, 0, 0, 0)) {
  -      size_t size = internal_strlen(demangled_name) + 1;
  -      char *buf = (char *)InternalAlloc(size);
  -      internal_memcpy(buf, demangled_name, size);
  -      free(demangled_name);
  -      return buf;
  -    }
  -  }
  +  // it does not allocate). For now, we just call it anyway, and we leak
  +  // the returned value.
  +  if (&__cxxabiv1::__cxa_demangle)
  +    if (const char *demangled_name =
  +          __cxxabiv1::__cxa_demangle(name, 0, 0, 0))
  +      return demangled_name;
   
  diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
  index a4d4cc73c482..ff05454aa920 100644
  --- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
  +++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
  @@ -2266,8 +2266,7 @@ bool ModuleAddressSanitizer::InstrumentGlobals(IRBuilder<> &IRB, Module &M,
   
  -    // The runtime library tries demangling symbol names in the descriptor but
  -    // functionality like __cxa_demangle may be unavailable (e.g.
  -    // -static-libstdc++). So we demangle the symbol names here.
  -    std::string NameForGlobal = G->getName().str();
  +    // TODO: Symbol names in the descriptor can be demangled by the runtime
  +    // library. This could save ~0.4% of VM size for a private large binary.
  +    std::string NameForGlobal = llvm::demangle(G->getName().str());
       GlobalVariable *Name =
  -        createPrivateGlobalForString(M, llvm::demangle(NameForGlobal),
  +        createPrivateGlobalForString(M, NameForGlobal,
                                        /*AllowMerging*/ true, kAsanGenPrefix);


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D138095/new/

https://reviews.llvm.org/D138095