[compiler-rt][Fuchsia] Disable interceptors while enabling new/delete replacements

[leonardchan]

Summary

This disables use of hwasan interceptors which we do not use on Fuchsia. This explicitly sets the macro for defining the hwasan versions of new/delete.

[mcgrathr]

compiler-rt/lib/hwasan/CMakeLists.txt

47

It might be better to force the value of COMPILER_RT_HWASAN_WITH_INTERCEPTORS to OFF instead.

But I'll leave the cmake details to Petr.

[phosek]

compiler-rt/lib/hwasan/CMakeLists.txt

47

That would be my preference. The patter we usually use is:

if(FUCHSIA)
  set(COMPILER_RT_HWASAN_WITH_INTERCEPTORS_DEFAULT OFF)
else()
  set(COMPILER_RT_HWASAN_WITH_INTERCEPTORS_DEFAULT ON)
endif()
set(COMPILER_RT_HWASAN_WITH_INTERCEPTORS ${COMPILER_RT_HWASAN_WITH_INTERCEPTORS_DEFAULT} CACHE BOOL "Enable libc interceptors in HWASan (testing mode)")

which would be set in https://github.com/llvm/llvm-project/blob/07c2a912ddf1641b969fdbae3418f77c362f67c6/compiler-rt/CMakeLists.txt#L70.

[leonardchan]

*ping*

[mcgrathr]

lgtm

compiler-rt/CMakeLists.txt

if (NOT COMPILER_RT_ASAN_SHADOW_SCALE STREQUAL "")
   set(COMPILER_RT_ASAN_SHADOW_SCALE_LLVM_FLAG
       -mllvm -asan-mapping-scale=${COMPILER_RT_ASAN_SHADOW_SCALE})
   set(COMPILER_RT_ASAN_SHADOW_SCALE_DEFINITION
       ASAN_SHADOW_SCALE=${COMPILER_RT_ASAN_SHADOW_SCALE})
   set(COMPILER_RT_ASAN_SHADOW_SCALE_FLAG
       -D${COMPILER_RT_ASAN_SHADOW_SCALE_DEFINITION})
 endif()
 
-set(COMPILER_RT_HWASAN_WITH_INTERCEPTORS ON CACHE BOOL
-    "Enable libc interceptors in HWASan (testing mode)")
+if(FUCHSIA)
+  set(COMPILER_RT_HWASAN_WITH_INTERCEPTORS_DEFAULT OFF)
+else()
+  set(COMPILER_RT_HWASAN_WITH_INTERCEPTORS_DEFAULT ON)
+endif()
+set(COMPILER_RT_HWASAN_WITH_INTERCEPTORS ${COMPILER_RT_HWASAN_WITH_INTERCEPTORS_DEFAULT} CACHE BOOL "Enable libc interceptors in HWASan (testing mode)")
 
 set(COMPILER_RT_BAREMETAL_BUILD OFF CACHE BOOL
   "Build for a bare-metal target.")
 
 if (COMPILER_RT_STANDALONE_BUILD)
   load_llvm_config()
   if (TARGET intrinsics_gen)
     # Loading the llvm config causes this target to be imported so place it

compiler-rt/lib/hwasan/CMakeLists.txt

set(HWASAN_RTL_HEADERS
   hwasan_poisoning.h
   hwasan_report.h
   hwasan_thread.h
   hwasan_thread_list.h
   )
 
 set(HWASAN_DEFINITIONS)
 append_list_if(COMPILER_RT_HWASAN_WITH_INTERCEPTORS HWASAN_WITH_INTERCEPTORS=1 HWASAN_DEFINITIONS)
 
+if(FUCHSIA)
+  # Set this explicitly on Fuchsia, otherwise the default value is set to HWASAN_WITH_INTERCEPTORS.
+  list(APPEND HWASAN_DEFINITIONS HWASAN_REPLACE_OPERATORS_NEW_AND_DELETE=1)
+endif()
+
 set(HWASAN_RTL_CFLAGS ${SANITIZER_COMMON_CFLAGS})
 append_rtti_flag(OFF HWASAN_RTL_CFLAGS)
 append_list_if(COMPILER_RT_HAS_FPIC_FLAG -fPIC HWASAN_RTL_CFLAGS)
 # Prevent clang from generating libc calls.
 append_list_if(COMPILER_RT_HAS_FFREESTANDING_FLAG -ffreestanding HWASAN_RTL_CFLAGS)
 
 set(HWASAN_DYNAMIC_LINK_FLAGS ${SANITIZER_COMMON_LINK_FLAGS})