X-Git-Url: https://git.cworth.org/git?a=blobdiff_plain;f=m4%2Finclude_next.m4;h=752263901c7ac0f084ae45180f4f533e742aed96;hb=refs%2Fheads%2F313237;hp=7c08e9319bf83cdb3ca6ee3b16ad679fc292fe3f;hpb=138fc7e67e3d9845cd7d81aad0e9c7724784f9b9;p=tar diff --git a/m4/include_next.m4 b/m4/include_next.m4 index 7c08e93..7522639 100644 --- a/m4/include_next.m4 +++ b/m4/include_next.m4 @@ -1,19 +1,46 @@ -# include_next.m4 serial 5 -dnl Copyright (C) 2006-2008 Free Software Foundation, Inc. +# include_next.m4 serial 11 +dnl Copyright (C) 2006-2009 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, dnl with or without modifications, as long as this notice is preserved. dnl From Paul Eggert and Derek Price. +dnl Sets INCLUDE_NEXT and PRAGMA_SYSTEM_HEADER. +dnl +dnl INCLUDE_NEXT expands to 'include_next' if the compiler supports it, or to +dnl 'include' otherwise. +dnl +dnl INCLUDE_NEXT_AS_FIRST_DIRECTIVE expands to 'include_next' if the compiler +dnl supports it in the special case that it is the first include directive in +dnl the given file, or to 'include' otherwise. +dnl +dnl PRAGMA_SYSTEM_HEADER can be used in files that contain #include_next, +dnl so as to avoid GCC warnings when the gcc option -pedantic is used. +dnl '#pragma GCC system_header' has the same effect as if the file was found +dnl through the include search path specified with '-isystem' options (as +dnl opposed to the search path specified with '-I' options). Namely, gcc +dnl does not warn about some things, and on some systems (Solaris and Interix) +dnl __STDC__ evaluates to 0 instead of to 1. The latter is an undesired side +dnl effect; we are therefore careful to use 'defined __STDC__' or '1' instead +dnl of plain '__STDC__'. + AC_DEFUN([gl_INCLUDE_NEXT], [ AC_LANG_PREPROC_REQUIRE() AC_CACHE_CHECK([whether the preprocessor supports include_next], [gl_cv_have_include_next], - [rm -rf conftestd1 conftestd2 - mkdir conftestd1 conftestd2 - cat < conftestd1/conftest.h + [rm -rf conftestd1a conftestd1b conftestd2 + mkdir conftestd1a conftestd1b conftestd2 + dnl The include of is because IBM C 9.0, 10.1 (original + dnl versions, prior to 2009-01 updates) on AIX 6.1 supports include_next + dnl when used as first preprocessor directive in a file, but not when + dnl preceded by another include directive. Additionally, with this same + dnl compiler, include_next is a no-op when used in a header file that was + dnl included by specifying its absolute file name. Despite these two bugs, + dnl include_next is used in the compiler's . By virtue of the + dnl second bug, we need to use include_next as well in this case. + cat < conftestd1a/conftest.h #define DEFINED_IN_CONFTESTD1 #include_next #ifdef DEFINED_IN_CONFTESTD2 @@ -21,6 +48,16 @@ int foo; #else #error "include_next doesn't work" #endif +EOF + cat < conftestd1b/conftest.h +#define DEFINED_IN_CONFTESTD1 +#include +#include_next +#ifdef DEFINED_IN_CONFTESTD2 +int foo; +#else +#error "include_next doesn't work" +#endif EOF cat < conftestd2/conftest.h #ifndef DEFINED_IN_CONFTESTD1 @@ -28,26 +65,37 @@ EOF #endif #define DEFINED_IN_CONFTESTD2 EOF - save_CPPFLAGS="$CPPFLAGS" - CPPFLAGS="$CPPFLAGS -Iconftestd1 -Iconftestd2" + gl_save_CPPFLAGS="$CPPFLAGS" + CPPFLAGS="$gl_save_CPPFLAGS -Iconftestd1b -Iconftestd2" AC_COMPILE_IFELSE([#include ], [gl_cv_have_include_next=yes], - [gl_cv_have_include_next=no]) - CPPFLAGS="$save_CPPFLAGS" - rm -rf conftestd1 conftestd2 + [CPPFLAGS="$gl_save_CPPFLAGS -Iconftestd1a -Iconftestd2" + AC_COMPILE_IFELSE([#include ], + [gl_cv_have_include_next=buggy], + [gl_cv_have_include_next=no]) + ]) + CPPFLAGS="$gl_save_CPPFLAGS" + rm -rf conftestd1a conftestd1b conftestd2 ]) + PRAGMA_SYSTEM_HEADER= if test $gl_cv_have_include_next = yes; then - - dnl FIXME: Remove HAVE_INCLUDE_NEXT and update everything that uses it - dnl to use @INCLUDE_NEXT@ instead. - AC_DEFINE([HAVE_INCLUDE_NEXT], 1, - [Define if your compiler supports the #include_next directive.]) - INCLUDE_NEXT=include_next + INCLUDE_NEXT_AS_FIRST_DIRECTIVE=include_next + if test -n "$GCC"; then + PRAGMA_SYSTEM_HEADER='#pragma GCC system_header' + fi else - INCLUDE_NEXT=include + if test $gl_cv_have_include_next = buggy; then + INCLUDE_NEXT=include + INCLUDE_NEXT_AS_FIRST_DIRECTIVE=include_next + else + INCLUDE_NEXT=include + INCLUDE_NEXT_AS_FIRST_DIRECTIVE=include + fi fi AC_SUBST([INCLUDE_NEXT]) + AC_SUBST([INCLUDE_NEXT_AS_FIRST_DIRECTIVE]) + AC_SUBST([PRAGMA_SYSTEM_HEADER]) ]) # gl_CHECK_NEXT_HEADERS(HEADER1 HEADER2 ...) @@ -69,9 +117,10 @@ EOF AC_DEFUN([gl_CHECK_NEXT_HEADERS], [ AC_REQUIRE([gl_INCLUDE_NEXT]) + AC_REQUIRE([AC_CANONICAL_HOST]) AC_CHECK_HEADERS_ONCE([$1]) - AC_FOREACH([gl_HEADER_NAME], [$1], + m4_foreach_w([gl_HEADER_NAME], [$1], [AS_VAR_PUSHDEF([gl_next_header], [gl_cv_next_]m4_quote(m4_defn([gl_HEADER_NAME]))) if test $gl_cv_have_include_next = yes; then @@ -87,11 +136,22 @@ AC_DEFUN([gl_CHECK_NEXT_HEADERS], [AC_LANG_SOURCE( [[#include <]]m4_dquote(m4_defn([gl_HEADER_NAME]))[[>]] )]) - dnl eval is necessary to expand ac_cpp. + dnl AIX "xlc -E" and "cc -E" omit #line directives for header files + dnl that contain only a #include of other header files and no + dnl non-comment tokens of their own. This leads to a failure to + dnl detect the absolute name of , , + dnl and others. The workaround is to force preservation of comments + dnl through option -C. This ensures all necessary #line directives + dnl are present. GCC supports option -C as well. + case "$host_os" in + aix*) gl_absname_cpp="$ac_cpp -C" ;; + *) gl_absname_cpp="$ac_cpp" ;; + esac + dnl eval is necessary to expand gl_absname_cpp. dnl Ultrix and Pyramid sh refuse to redirect output of eval, dnl so use subshell. AS_VAR_SET([gl_next_header], - ['"'`(eval "$ac_cpp conftest.$ac_ext") 2>&AS_MESSAGE_LOG_FD | + ['"'`(eval "$gl_absname_cpp conftest.$ac_ext") 2>&AS_MESSAGE_LOG_FD | sed -n '\#/]m4_quote(m4_defn([gl_HEADER_NAME]))[#{ s#.*"\(.*/]m4_quote(m4_defn([gl_HEADER_NAME]))[\)".*#\1# s#^/[^/]#//&#