[Bug plugins/65227] New: Plugin headers are unusable when included after inttypes.h

[Bert.Wesarg at googlemail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65227

            Bug ID: 65227
           Summary: Plugin headers are unusable when included after
                    inttypes.h
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: plugins
          Assignee: unassigned at gcc dot gnu.org
          Reporter: Bert.Wesarg at googlemail dot com

GCC 5 20150215 Snapshot.

When the gcc-plugin.h header is included after the inttypes.h header, than the
compilation breaks. Used compiler:

$ g++ -v
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/home/wesarg/opt/gcc-5-20150215/libexec/gcc/x86_64-unknown-linux-gnu/5.0.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ../configure --prefix=/home/wesarg/opt/gcc-5-20150215
--enable-languages=c,c++,fortran --disable-nls --enable-checking=yes
--disable-werror
Thread model: posix
gcc version 5.0.0 20150215 (experimental) (GCC) 

Compiling the attached file, which includes inttypes.h before gcc-plugin.h
results in this error:

$ g++ -save-temps -c -I$(g++ -print-file-name=plugin/include)
no-inttypes-pri-macros.cc 
In file included from
/home/wesarg/opt/gcc-5-20150215/lib/gcc/x86_64-unknown-linux-gnu/5.0.0/plugin/include/double-int.h:23:0,
                 from
/home/wesarg/opt/gcc-5-20150215/lib/gcc/x86_64-unknown-linux-gnu/5.0.0/plugin/include/gcc-plugin.h:52,
                 from no-inttypes-pri-macros.cc:2:
/home/wesarg/opt/gcc-5-20150215/lib/gcc/x86_64-unknown-linux-gnu/5.0.0/plugin/include/wide-int.h:
In member function 'void generic_wide_int<T>::dump() const':
/home/wesarg/opt/gcc-5-20150215/lib/gcc/x86_64-unknown-linux-gnu/5.0.0/plugin/include/wide-int.h:877:26:
error: expected ')' before 'PRIx64'
     fprintf (stderr, HOST_WIDE_INT_PRINT_HEX ",", val[len - 1 - i]);
                          ^
In file included from
/home/wesarg/opt/gcc-5-20150215/lib/gcc/x86_64-unknown-linux-gnu/5.0.0/plugin/include/double-int.h:23:0,
                 from
/home/wesarg/opt/gcc-5-20150215/lib/gcc/x86_64-unknown-linux-gnu/5.0.0/plugin/include/gcc-plugin.h:52,
                 from no-inttypes-pri-macros.cc:2:
/home/wesarg/opt/gcc-5-20150215/lib/gcc/x86_64-unknown-linux-gnu/5.0.0/plugin/include/wide-int.h:878:24:
error: expected ')' before 'PRIx64'
   fprintf (stderr, HOST_WIDE_INT_PRINT_HEX "], precision = %d\n",
                        ^
The reason seems to be, that system.h defines __STDC_FORMAT_MACROS, than
conditionally includes inttypes.h, and later hwint.h relys that this
conditional include has resulted in the definition of the PRI macros. But that
is not the case as the the include <inttypes.h> in system.h is not the first
inclusion of this header.