While investigating PR libstdc++/78979, it turned out that g++ on
Solaris should define the C11 value for __STDC_VERSION__ instead of the
C99 one when compiling for C++17.
That's what this patch does. It seemed safer to use the C99 value only
where we know it's needed, and default to the C11 one to be future-proof
for versions of C++ beyond 2017.
Bootstrapped without regressions on i386-pc-solaris2.1[10] and
sparc-sun-solaris2.12 (together with the soon-to-be-submitted patch for
the PR itself).
Unless Jon or someone else finds fault with the approach, I plan to
commit it to mainline soon.
Rainer
--
-----------------------------------------------------------------------------
Rainer Orth, Center for Biotechnology, Bielefeld University
2017-01-04 Rainer Orth <r...@cebitec.uni-bielefeld.de>
* config/sol2.h (TARGET_OS_CPP_BUILTINS): Define __STDC_VERSION__
to 201112L since C++17.
diff --git a/gcc/config/sol2.h b/gcc/config/sol2.h
--- a/gcc/config/sol2.h
+++ b/gcc/config/sol2.h
@@ -94,7 +94,22 @@ along with GCC; see the file COPYING3.
library. */ \
if (c_dialect_cxx ()) \
{ \
+ switch (cxx_dialect) \
+ { \
+ case cxx98: \
+ case cxx11: \
+ case cxx14: \
+ /* C++11 and C++14 are based on C99. \
+ libstdc++ makes use of C99 features \
+ even for C++98. */ \
builtin_define ("__STDC_VERSION__=199901L");\
+ break; \
+ \
+ default: \
+ /* C++17 is based on C11. */ \
+ builtin_define ("__STDC_VERSION__=201112L");\
+ break; \
+ } \
builtin_define ("_XOPEN_SOURCE=600"); \
builtin_define ("_LARGEFILE_SOURCE=1"); \
builtin_define ("_LARGEFILE64_SOURCE=1"); \
