1# warn-on-use.m4 serial 5 2dnl Copyright (C) 2010-2012 Free Software Foundation, Inc. 3dnl This file is free software; the Free Software Foundation 4dnl gives unlimited permission to copy and/or distribute it, 5dnl with or without modifications, as long as this notice is preserved. 6 7# gl_WARN_ON_USE_PREPARE(INCLUDES, NAMES) 8# --------------------------------------- 9# For each whitespace-separated element in the list of NAMES, define 10# HAVE_RAW_DECL_name if the function has a declaration among INCLUDES 11# even after being undefined as a macro. 12# 13# See warn-on-use.h for some hints on how to poison function names, as 14# well as ideas on poisoning global variables and macros. NAMES may 15# include global variables, but remember that only functions work with 16# _GL_WARN_ON_USE. Typically, INCLUDES only needs to list a single 17# header, but if the replacement header pulls in other headers because 18# some systems declare functions in the wrong header, then INCLUDES 19# should do likewise. 20# 21# It is generally safe to assume declarations for functions declared 22# in the intersection of C89 and C11 (such as printf) without 23# needing gl_WARN_ON_USE_PREPARE. 24AC_DEFUN([gl_WARN_ON_USE_PREPARE], 25[ 26 m4_foreach_w([gl_decl], [$2], 27 [AH_TEMPLATE([HAVE_RAW_DECL_]AS_TR_CPP(m4_defn([gl_decl])), 28 [Define to 1 if ]m4_defn([gl_decl])[ is declared even after 29 undefining macros.])])dnl 30dnl FIXME: gl_Symbol must be used unquoted until we can assume 31dnl autoconf 2.64 or newer. 32 for gl_func in m4_flatten([$2]); do 33 AS_VAR_PUSHDEF([gl_Symbol], [gl_cv_have_raw_decl_$gl_func])dnl 34 AC_CACHE_CHECK([whether $gl_func is declared without a macro], 35 gl_Symbol, 36 [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([$1], 37[@%:@undef $gl_func 38 (void) $gl_func;])], 39 [AS_VAR_SET(gl_Symbol, [yes])], [AS_VAR_SET(gl_Symbol, [no])])]) 40 AS_VAR_IF(gl_Symbol, [yes], 41 [AC_DEFINE_UNQUOTED(AS_TR_CPP([HAVE_RAW_DECL_$gl_func]), [1]) 42 dnl shortcut - if the raw declaration exists, then set a cache 43 dnl variable to allow skipping any later AC_CHECK_DECL efforts 44 eval ac_cv_have_decl_$gl_func=yes]) 45 AS_VAR_POPDEF([gl_Symbol])dnl 46 done 47]) 48