__has_feature() is a Clang-ism not implemented by GCC.
base/compiler_specific.h provides a HAS_FEATURE() macro that always
returns 0 when __has_feature() is not implemented. Use this macro for
compatibility with GCC and other compilers that do not implement this
Clang extension.
http://clang.llvm.org/docs/LanguageExtensions.html#has-feature-and-has-extension
For GCC’s Address Sanitizer implementation, test the
__SANITIZE_ADDRESS__ macro that it provides as an alternative to
__has_feature(address_sanitizer).
Note that in Chrome builds, ADDRESS_SANITIZER is pushed in by the build
system. The definition of ADDRESS_SANITIZER provides another way for
that macro to be set. It’s supplementary, not exclusive.
cb33b24372/build/config/BUILD.gn (118)
BUG=crashpad:30
Change-Id: I5c3145d29bbc966925369c03a37b1ecb5622a004
Reviewed-on: https://chromium-review.googlesource.com/413109
Reviewed-by: Robert Sesek <rsesek@chromium.org>
Under asan, there are many more instructions than without. The “nearby
PC” check is much less useful, and would likely fail.
TEST=crashpad_client_test CaptureContext.CaptureContext
R=rsesek@chromium.org
Review URL: https://codereview.chromium.org/1298943003 .
implicit_cast<> only performs a cast in cases where an implicit
conversion would be possible. It’s even safer than static_cast<> It’s an
“explicit implicit” cast, which is not normally necsesary, but is
frequently required when working with the ?: operator, functions like
std::min() and std::max(), and logging and testing macros.
The public style guide does not mention implicit_cast<> only because it
is not part of the standard library, but would otherwise require it in
these situations. Since base does provide implicit_cast<>, it should be
used whenever possible.
The only uses of static_cast<> not converted to implicit_cast<> are
those that require static_cast<>, such as those that assign an integer
constant to a variable of an enum type.
R=rsesek@chromium.org
Review URL: https://codereview.chromium.org/700383007
