On Fri, Nov 14, 2014 at 8:18 AM, Jakub Jelinek <ja...@redhat.com> wrote: > On Tue, Nov 11, 2014 at 11:46:55AM +0100, Richard Biener wrote: >> > BTW: There are lots of places where std::swap can be used, a nice >> > search-and-replace task for someone to start with gcc development. ;) >> >> Agreed ;) Note that we have to be careful to avoid pulling all of libstdc++ >> into all files via system.h (system.h is so a bad thing... :/). > > Apparently the nvptx port is another thing that fails to build because of > the header ordering issues, this time not just when starting with clang, but > just when building cross-compiler starting from gcc 4.9.1 on x86_64. > > There is: > > #include "config.h" > #include "system.h" > ... > #include "hashtab.h" > #include <sstream> > > and I get: > g++ -c -g -DIN_GCC -DCROSS_DIRECTORY_STRUCTURE -fno-exceptions -fno-rtti > -fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings > -Wcast-qual -Wmissing-format-attribute -Woverloaded-virtual -pedantic > -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -fno-common > -DHAVE_CONFIG_H -I. -I. -I../../gcc -I../../gcc/. -I../../gcc/../include > -I../../gcc/../libcpp/include -I../../gcc/../libdecnumber > -I../../gcc/../libdecnumber/dpd -I../libdecnumber -I../../gcc/../libbacktrace > -o nvptx.o -MT nvptx.o -MMD -MP -MF ./.deps/nvptx.TPo > ../../gcc/config/nvptx/nvptx.c > In file included from /usr/include/c++/4.9.1/bits/basic_ios.h:37:0, > from /usr/include/c++/4.9.1/ios:44, > from /usr/include/c++/4.9.1/istream:38, > from /usr/include/c++/4.9.1/sstream:38, > from ../../gcc/config/nvptx/nvptx.c:54: > /usr/include/c++/4.9.1/bits/locale_facets.h:240:53: error: macro "toupper" > passed 2 arguments, but takes just 1 > toupper(char_type *__lo, const char_type* __hi) const > ^ > and many more. > As you said that we don't want to pull all of libstdc++ > headers via system.h, looking at system.h, I see just the > > /* Define this so that inttypes.h defines the PRI?64 macros even > when compiling with a C++ compiler. Define it here so in the > event inttypes.h gets pulled in by another header it is already > defined. */ > #define __STDC_FORMAT_MACROS > > macro being critical to be included before any system headers, > can't we move that into config.in/auto-host.h and just suggest > header ordering of > > #include "config.h" > #include <sstream> // or any other extra STL headers not provided by system.h > you need > #include "system.h" > all other includes
Ick. > ? There are also some comments about stdarg.h and stdio.h ordering, > dunno what it comes from and if it is still relevant when we require > C++ compiler. I think we should simply discourage people from using sstream for example. But I don't see how we can live without system.h with all the weird host systems still around - thus your solution above will very likely not work. Eventually we can split system.h into a c-system.h and cxx-system.h so we can distinguish between uses in files compiled with a C and a C++ compiler? Richard. > Jakub
