Elapsed: 0.24s; From ../../dist/idl: Kept 936 existing; Added/updated 0; Removed 0 files and 0 directories. In file included from /root/firefox-gcc-last/obj-x86_64-pc-linux-gnu/dist/include/mozilla/FloatingPoint.h:15, from /root/firefox-gcc-last/mfbt/decimal/moz-decimal-utils.h:16, from /root/firefox-gcc-last/mfbt/decimal/Decimal.cpp:32: /root/firefox-gcc-last/obj-x86_64-pc-linux-gnu/dist/include/mozilla/MathAlgorithms.h:568:58: error: 'unsigned-integer-overflow' attribute directive ignored [-Werror=attributes] static constexpr SignedType compute(UnsignedType aValue) ^ gcc 8 has no_sanitize but not the unsigned-integer-overflow/signed-integer-overflow

Comment on attachment 8950168 [details] Bug 1437482 - gcc 8 has no-sanitize but not the {un,}signed-integer-overflow option https://reviewboard.mozilla.org/r/219436/#review225346 ::: mfbt/Attributes.h:280 (Diff revision 1) > -# define MOZ_NO_SANITIZE_UNSIGNED_OVERFLOW __attribute__((no_sanitize("unsigned-integer-overflow"))) > +# if __has_attribute(__no_sanitize_unsigned_integer_overflow__) > +# define MOZ_NO_SANITIZE_UNSIGNED_OVERFLOW __attribute__((no_sanitize("unsigned-integer-overflow"))) > +# else > +/** > + * gcc 8 has no-sanitize but not the unsigned-integer-overflow option > + */ If MOZ_HAVE_NO_SANITIZE_ATTR doesn't match what these macros need, we shouldn't bother with it, and we should just use the exact necessary logic at the two definition-sites. In other words the #define MOZ_HAVE_NO_SANITIZE_ATTR goo above should be eliminated and the relevant testing inlined into these two sites. That said, this change doesn't work for me. [jwalden@find-waldo-now tmp]$ cat t.cpp #if __has_attribute(__no_sanitize_unsigned_integer_overflow__) #error "have it" #endif [jwalden@find-waldo-now tmp]$ clang++-tip -fsanitize=unsigned-integer-overflow t.cpp 2>&1 | grep 'have it' [jwalden@find-waldo-now tmp]$ clang++-tip -fsanitize=integer-overflow t.cpp 2>&1 | grep 'have it' [jwalden@find-waldo-now tmp]$ clang++-tip t.cpp 2>&1 | grep 'have it' [jwalden@find-waldo-now tmp]$ clang++-tip --version clang version 6.0.0 (trunk 317840) Target: x86_64-unknown-linux-gnu Thread model: posix InstalledDir: /home/jwalden/.programs/new-compilers Internet searches don't find the attribute you've tested with, and I can't find anything in clang docs that can be used to feature-test specifically for this. https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html#disabling-instrumentation-with-attribute-no-sanitize-undefined recommends a very high-level `#ifdef __clang__` check, so I would probably write it, regrettably, using some flavor of that.

Comment on attachment 8950168 [details] Bug 1437482 - gcc 8 has no-sanitize but not the {un,}signed-integer-overflow option https://reviewboard.mozilla.org/r/219436/#review226710

Pushed by sledru@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/24117c13a404 gcc 8 has no-sanitize but not the {un,}signed-integer-overflow option r=Waldo