diff options
Diffstat (limited to 'gl/m4/include_next.m4')
| -rw-r--r-- | gl/m4/include_next.m4 | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/gl/m4/include_next.m4 b/gl/m4/include_next.m4 new file mode 100644 index 00000000..7ce472bc --- /dev/null +++ b/gl/m4/include_next.m4 @@ -0,0 +1,107 @@ +# include_next.m4 serial 4 +dnl Copyright (C) 2006, 2007 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. + +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 <<EOF > conftestd1/conftest.h +#define DEFINED_IN_CONFTESTD1 +#include_next <conftest.h> +#ifdef DEFINED_IN_CONFTESTD2 +int foo; +#else +#error "include_next doesn't work" +#endif +EOF + cat <<EOF > conftestd2/conftest.h +#ifndef DEFINED_IN_CONFTESTD1 +#error "include_next test doesn't work" +#endif +#define DEFINED_IN_CONFTESTD2 +EOF + save_CPPFLAGS="$CPPFLAGS" + CPPFLAGS="$CPPFLAGS -Iconftestd1 -Iconftestd2" + AC_COMPILE_IFELSE([#include <conftest.h>], + [gl_cv_have_include_next=yes], + [gl_cv_have_include_next=no]) + CPPFLAGS="$save_CPPFLAGS" + rm -rf conftestd1 conftestd2 + ]) + 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 + else + INCLUDE_NEXT=include + fi + AC_SUBST([INCLUDE_NEXT]) +]) + +# gl_CHECK_NEXT_HEADERS(HEADER1 HEADER2 ...) +# ------------------------------------------ +# For each arg foo.h, if #include_next works, define NEXT_FOO_H to be +# '<foo.h>'; otherwise define it to be +# '"///usr/include/foo.h"', or whatever other absolute file name is suitable. +# That way, a header file with the following line: +# #@INCLUDE_NEXT@ @NEXT_FOO_H@ +# behaves (after sed substitution) as if it contained +# #include_next <foo.h> +# even if the compiler does not support include_next. +# The three "///" are to pacify Sun C 5.8, which otherwise would say +# "warning: #include of /usr/include/... may be non-portable". +# Use `""', not `<>', so that the /// cannot be confused with a C99 comment. +AC_DEFUN([gl_CHECK_NEXT_HEADERS], +[ + AC_REQUIRE([gl_INCLUDE_NEXT]) + AC_CHECK_HEADERS_ONCE([$1]) + + AC_FOREACH([gl_HEADER_NAME], [$1], + [AS_VAR_PUSHDEF([gl_next_header], + [gl_cv_next_]m4_quote(m4_defn([gl_HEADER_NAME]))) + if test $gl_cv_have_include_next = yes; then + AS_VAR_SET([gl_next_header], ['<'gl_HEADER_NAME'>']) + else + AC_CACHE_CHECK( + [absolute name of <]m4_quote(m4_defn([gl_HEADER_NAME]))[>], + m4_quote(m4_defn([gl_next_header])), + [AS_VAR_PUSHDEF([gl_header_exists], + [ac_cv_header_]m4_quote(m4_defn([gl_HEADER_NAME]))) + if test AS_VAR_GET(gl_header_exists) = yes; then + AC_LANG_CONFTEST( + [AC_LANG_SOURCE( + [[#include <]]m4_dquote(m4_defn([gl_HEADER_NAME]))[[>]] + )]) + dnl eval is necessary to expand ac_cpp. + dnl Ultrix and Pyramid sh refuse to redirect output of eval, + dnl so use subshell. + AS_VAR_SET([gl_next_header], + ['"'`(eval "$ac_cpp conftest.$ac_ext") 2>&AS_MESSAGE_LOG_FD | + sed -n '\#/]m4_quote(m4_defn([gl_HEADER_NAME]))[#{ + s#.*"\(.*/]m4_quote(m4_defn([gl_HEADER_NAME]))[\)".*#\1# + s#^/[^/]#//&# + p + q + }'`'"']) + else + AS_VAR_SET([gl_next_header], ['<'gl_HEADER_NAME'>']) + fi + AS_VAR_POPDEF([gl_header_exists])]) + fi + AC_SUBST( + AS_TR_CPP([NEXT_]m4_quote(m4_defn([gl_HEADER_NAME]))), + [AS_VAR_GET([gl_next_header])]) + AS_VAR_POPDEF([gl_next_header])]) +]) |