Add C++17 aligned new/delete entrypoints to libasan

[jakubjelinek]

Summary

This is the shorter version of http://gcc.gnu.org/PR77567 changes, which just adds the C++17 operator new/delete/new[]/delete[] entrypoints with std::align_val_t arguments, but doesn't verify the C++17 requirement that non-std::align_val_t allocation isn't mixed with std::align_val_t deallocation and vice versa, because there are no bits left right now in the libasan structures to record this, but at least it complains if you malloc/memalign and deallocate using delete operator with std::align_val_t, etc.

[kcc]

An interesting question is how to test it upstream.
According to http://clang.llvm.org/cxx_status.html these variants of operator new are not yet supported by clang.

Did you test it on Mac? I am not sure it will work this way.
If not, I would just leave the Mac section unchanged (with a TODO there).

[kcc]

Did you test it on Mac? I am not sure it will work this way.

Scratch that. I was confused because the patch did not have the full context.
Please upload patch with full context next time.

[jakubjelinek]

An interesting question is how to test it upstream.

In theory you could just test it even with C++11, with something like:

#include <new>

#if !__cpp_aligned_new
namespace std {
  enum class align_val_t : size_t {};
}
void* operator new(std::size_t, std::align_val_t);
void operator delete(void*, std::align_val_t) noexcept;
#endif

int
main ()
{
#if !__cpp_aligned_new
  void *p = operator new(8*sizeof(int), std::align_val_t(8*alignof(int)));
  operator delete(p, std::align_val_t(8*alignof(int)));
#endif
  return 0;
}

(similarly provide other prototypes of the operators, etc.), and then test the various mismatches (like allocation with memalign/posix_memalign vs. operator delete with std::align_val_t, vice versa etc. Due to the lack of spare bits obviously diagnostics of std::align_val_t operators vs. non-std::align_val_t will not work for now.

Did you test it on Mac?

No, and that is why I haven't changed anything in the SANITIZER_MAC sections.

[kcc]

LGTM.
Sanity-tested and committed as r282019.

Thanks!

[Eugene.Zelenko]

Committed in r282019.

compiler-rt/lib/asan/asan_new_delete.cc

 
 using namespace __asan;  // NOLINT
 
+// FreeBSD prior v9.2 have wrong definition of 'size_t'.
+// http://svnweb.freebsd.org/base?view=revision&revision=232261
+#if SANITIZER_FREEBSD && SANITIZER_WORDSIZE == 32
+#include <sys/param.h>
+#if __FreeBSD_version <= 902001  // v9.2
+#define size_t unsigned
+#endif  // __FreeBSD_version
+#endif  // SANITIZER_FREEBSD && SANITIZER_WORDSIZE == 32
+
 // This code has issues on OSX.
 // See https://github.com/google/sanitizers/issues/131.
 
-// Fake std::nothrow_t to avoid including <new>.
+// Fake std::nothrow_t and std::align_val_t to avoid including <new>.
 namespace std {
 struct nothrow_t {};
+enum class align_val_t: size_t {};
 }  // namespace std
 
 #define OPERATOR_NEW_BODY(type) \
   GET_STACK_TRACE_MALLOC;\
   return asan_memalign(0, size, &stack, type);
+#define OPERATOR_NEW_BODY_ALIGN(type) \
+  GET_STACK_TRACE_MALLOC;\
+  return asan_memalign((uptr)align, size, &stack, type);
 
 // On OS X it's not enough to just provide our own 'operator new' and
 // 'operator delete' implementations, because they're going to be in the

 // To make sure that C++ allocation/deallocation operators are overridden on
 // OS X we need to intercept them using their mangled names.
 #if !SANITIZER_MAC
-// FreeBSD prior v9.2 have wrong definition of 'size_t'.
-// http://svnweb.freebsd.org/base?view=revision&revision=232261
-#if SANITIZER_FREEBSD && SANITIZER_WORDSIZE == 32
-#include <sys/param.h>
-#if __FreeBSD_version <= 902001  // v9.2
-#define size_t unsigned
-#endif  // __FreeBSD_version
-#endif  // SANITIZER_FREEBSD && SANITIZER_WORDSIZE == 32
-
 CXX_OPERATOR_ATTRIBUTE
 void *operator new(size_t size) { OPERATOR_NEW_BODY(FROM_NEW); }
 CXX_OPERATOR_ATTRIBUTE

 CXX_OPERATOR_ATTRIBUTE
 void *operator new[](size_t size, std::nothrow_t const&)
 { OPERATOR_NEW_BODY(FROM_NEW_BR); }
+CXX_OPERATOR_ATTRIBUTE
+void *operator new(size_t size, std::align_val_t align)
+{ OPERATOR_NEW_BODY_ALIGN(FROM_NEW); }
+CXX_OPERATOR_ATTRIBUTE
+void *operator new[](size_t size, std::align_val_t align)
+{ OPERATOR_NEW_BODY_ALIGN(FROM_NEW_BR); }
+CXX_OPERATOR_ATTRIBUTE
+void *operator new(size_t size, std::align_val_t align, std::nothrow_t const&)
+{ OPERATOR_NEW_BODY_ALIGN(FROM_NEW); }
+CXX_OPERATOR_ATTRIBUTE
+void *operator new[](size_t size, std::align_val_t align, std::nothrow_t const&)
+{ OPERATOR_NEW_BODY_ALIGN(FROM_NEW_BR); }
 
 #else  // SANITIZER_MAC
 INTERCEPTOR(void *, _Znwm, size_t size) {

   GET_STACK_TRACE_FREE;
   asan_sized_free(ptr, size, &stack, FROM_NEW_BR);
 }
+CXX_OPERATOR_ATTRIBUTE
+void operator delete(void *ptr, std::align_val_t) NOEXCEPT {
+  OPERATOR_DELETE_BODY(FROM_NEW);
+}
+CXX_OPERATOR_ATTRIBUTE
+void operator delete[](void *ptr, std::align_val_t) NOEXCEPT {
+  OPERATOR_DELETE_BODY(FROM_NEW_BR);
+}
+CXX_OPERATOR_ATTRIBUTE
+void operator delete(void *ptr, std::align_val_t, std::nothrow_t const&) {
+  OPERATOR_DELETE_BODY(FROM_NEW);
+}
+CXX_OPERATOR_ATTRIBUTE
+void operator delete[](void *ptr, std::align_val_t, std::nothrow_t const&) {
+  OPERATOR_DELETE_BODY(FROM_NEW_BR);
+}
+CXX_OPERATOR_ATTRIBUTE
+void operator delete(void *ptr, size_t size, std::align_val_t) NOEXCEPT {
+  GET_STACK_TRACE_FREE;
+  asan_sized_free(ptr, size, &stack, FROM_NEW);
+}
+CXX_OPERATOR_ATTRIBUTE
+void operator delete[](void *ptr, size_t size, std::align_val_t) NOEXCEPT {
+  GET_STACK_TRACE_FREE;
+  asan_sized_free(ptr, size, &stack, FROM_NEW_BR);
+}
 
 #else  // SANITIZER_MAC
 INTERCEPTOR(void, _ZdlPv, void *ptr) {