[cfe-dev] Clang++ and _FORTIFY_SOURCE: Supported or not?
John Snow via cfe-dev
cfe-dev at lists.llvm.org
Mon Nov 2 16:27:30 PST 2015
I'm trying to find an official notice of support (or a contrary notice)
for Clang++ and -D_FORTIFY_SOURCE=2.
The QEMU project ran into an issue recently  where Clang++
(3.5.0-9.fc22) failed to compile certain files because it does not have
definitions for __builtin_va_pack_len (and friends). This kicks up
errors when using glibc, cstdio and _FORTIFY_SOURCE together.
When researching the problem, we ran across an llvm bug  where
Richard Smith states: "_FORTIFY_SOURCE + glibc + clang is not supported
and does not work".
However, in testing Clang++ 3.7.0-1.fc23, I notice that
-D_FORTIFY_SOURCE does indeed appear to work. Is that a fluke, or do
modern versions (>3.5.0) of Clang actually support this combination?
I can't find official documentation pointing towards either support or
exclusion of this feature, so a firm answer pointing to either direction
would be helpful.
 QEMU discussion:
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