[scudo][standalone] Potential fix for missing sized delete

[cryptoad]

Summary

In some setups, using -fsized-deallocation would end up not finding
a sized delete operator at link time. For now, avoid using the flag
and declare the sized delete operator in the cpp test only.

This is a tentative fix as I do not have the failing setup.

[cryptoad]

s/kostya/kostyak/

[rnk]

lgtm

I see. But won't there still be link errors for the cpp test? Anyway, I'll try to reproduce the build our Chromium bot uses. I filed https://crbug.com/980389 to track it.

[rnk]

In D64086#1567106, @rnk wrote:

I see. But won't there still be link errors for the cpp test? Anyway, I'll try to reproduce the build our Chromium bot uses. I filed https://crbug.com/980389 to track it.

I see your answers to these questions in https://crbug.com/980389#c1. Sounds good.

lib/scudo/standalone/tests/CMakeLists.txt

 include_directories(..)
 
 add_custom_target(ScudoUnitTests)
 set_target_properties(ScudoUnitTests PROPERTIES
   FOLDER "Compiler-RT Tests")
 
 set(SCUDO_UNITTEST_CFLAGS
   ${COMPILER_RT_UNITTEST_CFLAGS}
   ${COMPILER_RT_GTEST_CFLAGS}
   -I${COMPILER_RT_SOURCE_DIR}/include
   -I${COMPILER_RT_SOURCE_DIR}/lib
   -I${COMPILER_RT_SOURCE_DIR}/lib/scudo/standalone
   -DGTEST_HAS_RTTI=0
   # Extra flags for the C++ tests
-  -fsized-deallocation
+  # TODO(kostya): find a way to make -fsized-deallocation work
   -Wno-mismatched-new-delete)
 
 set(SCUDO_TEST_ARCH ${SCUDO_STANDALONE_SUPPORTED_ARCH})
 
 # gtests requires c++
 set(LINK_FLAGS ${COMPILER_RT_UNITTEST_LINK_FLAGS})
 foreach(lib ${SANITIZER_TEST_CXX_LIBRARIES})
   list(APPEND LINK_FLAGS -l${lib})

lib/scudo/standalone/tests/wrappers_cpp_test.cc

 //===-- wrappers_cpp_test.cc ------------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "gtest/gtest.h"
 
 #include <condition_variable>
 #include <mutex>
 #include <thread>
 
+void operator delete(void *, size_t) noexcept;
+void operator delete[](void *, size_t) noexcept;
+
 // Note that every Cxx allocation function in the test binary will be fulfilled
 // by Scudo. See the comment in the C counterpart of this file.
 
 extern "C" __attribute__((visibility("default"))) const char *
 __scudo_default_options() {
   return "quarantine_size_kb=256:thread_local_quarantine_size_kb=128:"
          "quarantine_max_chunk_size=512:dealloc_type_mismatch=true";
 }