[sanitizer][asan][win] Intercept _strdup on windows instead of strdup.

[barcharcraz]

Summary

Intercept _strdup on windows, instead of strdup (which doesn't exist).

I'm not a committer yet, so I'll need someone to merge this for me.

(update: adding llvm-commits, which I didn't know I needed to add manually)

[vitalybuka]

compiler-rt/lib/asan/asan_interceptors.cpp

494

can you move this to the and of the file?
so you don't need #if around ASAN_INTERCEPT_FUNC

[barcharcraz]

• move the macro to the end of the file.
• clang-format

[barcharcraz]

Can someone commit this? It should be good to go and I don't have commit access (long term I will probably be requesting commit access)

[barcharcraz]

I forgot to add llvm-commits as a subscriber here (I guess simply setting the repository field correctly is not enough), so it's been stuck on accepted for a while. I think this still applies cleanly though.

Could someone commit this?

[barcharcraz]

This was merged as 31263211c6a4ef454216f2edbf9b2083a4c1474d, but the magic words to close the revision were missing.

compiler-rt/lib/asan/asan_interceptors.cpp

if (flags()->replace_str) {
     uptr from_size = internal_strlen(from) + 1;
     CHECK_RANGES_OVERLAP("strcpy", to, from_size, from, from_size);
     ASAN_READ_RANGE(ctx, from, from_size);
     ASAN_WRITE_RANGE(ctx, to, from_size);
   }
   return REAL(strcpy)(to, from);
 }
 
+// Windows doesn't always define the strdup identifier,
+// and when it does it's a macro defined to either _strdup
+// or _strdup_dbg, _strdup_dbg ends up calling _strdup, so
+// we want to intercept that. push/pop_macro are used to avoid problems
+// if this file ends up including <string.h> in the future.
+#  if SANITIZER_WINDOWS
+#    pragma push_macro("strdup")
+#    undef strdup
+#    define strdup _strdup
+#  endif
+
 INTERCEPTOR(char*, strdup, const char *s) {
   void *ctx;
   ASAN_INTERCEPTOR_ENTER(ctx, strdup);
   if (UNLIKELY(!asan_inited)) return internal_strdup(s);
   ENSURE_ASAN_INITED();
   uptr length = internal_strlen(s);
   if (flags()->replace_str) {
     ASAN_READ_RANGE(ctx, s, length + 1);
   }
   GET_STACK_TRACE_MALLOC;
   void *new_mem = asan_malloc(length + 1, &stack);
   if (new_mem) {
     REAL(memcpy)(new_mem, s, length + 1);
   }
   return reinterpret_cast<char*>(new_mem);
 }
 
-#if ASAN_INTERCEPT___STRDUP
+#  if ASAN_INTERCEPT___STRDUP
 INTERCEPTOR(char*, __strdup, const char *s) {
   void *ctx;
   ASAN_INTERCEPTOR_ENTER(ctx, strdup);
   if (UNLIKELY(!asan_inited)) return internal_strdup(s);
   ENSURE_ASAN_INITED();
   uptr length = internal_strlen(s);
   if (flags()->replace_str) {
     ASAN_READ_RANGE(ctx, s, length + 1);
void InitializeAsanInterceptors() {
   InitializeSignalInterceptors();
 
   // Intercept str* functions.
   ASAN_INTERCEPT_FUNC(strcat);
   ASAN_INTERCEPT_FUNC(strcpy);
   ASAN_INTERCEPT_FUNC(strncat);
   ASAN_INTERCEPT_FUNC(strncpy);
   ASAN_INTERCEPT_FUNC(strdup);
-#if ASAN_INTERCEPT___STRDUP
+#  if ASAN_INTERCEPT___STRDUP
   ASAN_INTERCEPT_FUNC(__strdup);
 #endif
 #if ASAN_INTERCEPT_INDEX && ASAN_USE_ALIAS_ATTRIBUTE_FOR_INDEX
   ASAN_INTERCEPT_FUNC(index);
 #endif
 
   ASAN_INTERCEPT_FUNC(atoi);
   ASAN_INTERCEPT_FUNC(atol);
#if ASAN_INTERCEPT_VFORK
   ASAN_INTERCEPT_FUNC(vfork);
 #endif
 
   InitializePlatformInterceptors();
 
   VReport(1, "AddressSanitizer: libc interceptors initialized\n");
 }
 
+#  if SANITIZER_WINDOWS
+#    pragma pop_macro("strdup")
+#  endif
+
 } // namespace __asan
 
 #endif  // !SANITIZER_FUCHSIA