glob: fix failure in C++ mode

[Bruno Haible]

$ ./gnulib-tool --create-testdir --dir=../testdir-glob --single-configure --with-c++-tests glob
produces a testdir that, when compiled on a glibc 2.23 system, produces errors:

depbase=`echo test-glob-c++.o | sed 's|[^/]*$|.deps/&|;s|\.o$||'`;\
g++ -DHAVE_CONFIG_H -I. -I.. -DGNULIB_STRICT_CHECKING=1 -DIN_GNULIB_TESTS=1 -I. -I. -I.. -I./.. -I../gllib -I./../gllib -MT test-glob-c++.o -MD -MP -MF $depbase.Tpo -c -o test-glob-c++.o test-glob-c++.cc &&\
mv -f $depbase.Tpo $depbase.Po
In file included from /usr/include/x86_64-linux-gnu/sys/types.h:219:0,
from ../gllib/sys/types.h:28,
from ../gllib/sys/stat.h:41,
from ../gllib/glob.h:31,
from test-glob-c++.cc:22:
../gllib/glob.h:56:54: error: expected ',' or '...' before '__pattern'
_GL_CXXALIAS_RPL (glob, int, (const char *_Restrict_ __pattern, int __flags,
^
...
Makefile:3470: recipe for target 'test-glob-c++.o' failed
make[4]: *** [test-glob-c++.o] Error 1

This fixes it.


2018-03-15 Bruno Haible <***@clisp.org>

glob: Fix compilation error in C++ mode.
* lib/glob.in.h (_Restrict_): Define, like in regex.h and spawn.in.h.

diff --git a/lib/glob.in.h b/lib/glob.in.h
index 4d71ef8..cc3f48c 100644
--- a/lib/glob.in.h
+++ b/lib/glob.in.h
@@ -33,6 +33,21 @@
# define __USE_GNU 1
#endif

+/* GCC 2.95 and later have "__restrict"; C99 compilers have
+ "restrict", and "configure" may have defined "restrict".
+ Other compilers use __restrict, __restrict__, and _Restrict, and
+ 'configure' might #define 'restrict' to those words, so pick a
+ different name. */
+#ifndef _Restrict_
+# if 199901L <= __STDC_VERSION__
+# define _Restrict_ restrict
+# elif 2 < __GNUC__ || (2 == __GNUC__ && 95 <= __GNUC_MINOR__)
+# define _Restrict_ __restrict
+# else
+# define _Restrict_
+# endif
+#endif
+

#define glob rpl_glob
#define globfree rpl_globfree