Ensure that only one compiler-rt component is created for lsan

[fjricci]

Summary

The lsan cmake configuration failed when targeting more
than one architecture, because it would attempt to create multiple
components with the same name. Ensure that only one lsan component
is ever created.

[fjricci]

Update to use individual symbols names

[fjricci]

Undo upload of incorrect commit

cmake/config-ix.cmake

if(APPLE)
   # We're setting the flag manually for each target OS
   set(CMAKE_OSX_DEPLOYMENT_TARGET "")
   
   set(DARWIN_COMMON_CFLAGS -stdlib=libc++)
   set(DARWIN_COMMON_LINKFLAGS
     -stdlib=libc++
     -lc++
     -lc++abi)
-  
+  set(DARWIN_WEAK_SYMBOLS
+      ___asan_default_options
+      ___asan_default_suppressions
+      ___asan_on_error
+      ___lsan_default_suppressions
+      ___lsan_is_turned_off
+      ___sanitizer_free_hook
+      ___sanitizer_malloc_hook
+      ___sanitizer_symbolize_code
+      ___sanitizer_symbolize_data
+      ___sanitizer_symbolize_demangle
+      ___sanitizer_symbolize_flush
+      ___ubsan_default_options)
+
+  foreach(SYMBOL ${DARWIN_WEAK_SYMBOLS})
+    set(DARWIN_COMMON_LINKFLAGS ${DARWIN_COMMON_LINKFLAGS} -Wl,-U,${SYMBOL})
+  endforeach()
+  
   check_linker_flag("-fapplication-extension" COMPILER_RT_HAS_APP_EXTENSION)
   if(COMPILER_RT_HAS_APP_EXTENSION)
     list(APPEND DARWIN_COMMON_LINKFLAGS "-fapplication-extension")
   endif()
 
   set(DARWIN_osx_CFLAGS
     ${DARWIN_COMMON_CFLAGS}
     -mmacosx-version-min=${SANITIZER_MIN_OSX_VERSION})

lib/lsan/CMakeLists.txt

 
 add_compiler_rt_object_libraries(RTLSanCommon
     OS ${SANITIZER_COMMON_SUPPORTED_OS}
     ARCHS ${LSAN_COMMON_SUPPORTED_ARCH}
     SOURCES ${LSAN_COMMON_SOURCES}
     CFLAGS ${LSAN_CFLAGS})
 
 if(COMPILER_RT_HAS_LSAN)
-  foreach(arch ${LSAN_SUPPORTED_ARCH})
-    add_compiler_rt_component(lsan)
-    
+  foreach(arch ${LSAN_SUPPORTED_ARCH})
     add_compiler_rt_runtime(clang_rt.lsan
       STATIC
       ARCHS ${arch}
       SOURCES ${LSAN_SOURCES}
               $<TARGET_OBJECTS:RTInterception.${arch}>
               $<TARGET_OBJECTS:RTSanitizerCommon.${arch}>
               $<TARGET_OBJECTS:RTSanitizerCommonLibc.${arch}>
               $<TARGET_OBJECTS:RTLSanCommon.${arch}>
       CFLAGS ${LSAN_CFLAGS}
       PARENT_TARGET lsan)
   endforeach()
 endif()

lib/lsan/lsan_allocator.cc

 
 SANITIZER_INTERFACE_ATTRIBUTE
 int __sanitizer_get_ownership(const void *p) { return Metadata(p) != nullptr; }
 
 SANITIZER_INTERFACE_ATTRIBUTE
 uptr __sanitizer_get_allocated_size(const void *p) {
   return GetMallocUsableSize(p);
 }
+
+#if !SANITIZER_SUPPORTS_WEAK_HOOKS
+// Provide default (no-op) implementation of malloc hooks.
+SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+void __sanitizer_malloc_hook(void *ptr, uptr size) {
+  (void)ptr;
+  (void)size;
+}
+SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+void __sanitizer_free_hook(void *ptr) {
+  (void)ptr;
+}
+#endif
 } // extern "C"

lib/lsan/lsan_common.cc

#endif // CAN_SANITIZE_LEAKS
   return 0;
 }
 
 #if !SANITIZER_SUPPORTS_WEAK_HOOKS
 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
 int __lsan_is_turned_off() {
   return 0;
 }
+
+SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+const char *__lsan_default_suppressions() {
+  return "";
+}
 #endif
 } // extern "C"