1# warn-on-use.m4 serial 6 2dnl Copyright (C) 2010-2020 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# If the module 'posixcheck' is in use: 10# 11# For each whitespace-separated element in the list of NAMES, define 12# HAVE_RAW_DECL_name if the function has a declaration among INCLUDES 13# even after being undefined as a macro. 14# 15# See warn-on-use.h for some hints on how to poison function names, as 16# well as ideas on poisoning global variables and macros. NAMES may 17# include global variables, but remember that only functions work with 18# _GL_WARN_ON_USE. Typically, INCLUDES only needs to list a single 19# header, but if the replacement header pulls in other headers because 20# some systems declare functions in the wrong header, then INCLUDES 21# should do likewise. 22# 23# It is generally safe to assume declarations for functions declared 24# in the intersection of C89 and C11 (such as printf) without 25# needing gl_WARN_ON_USE_PREPARE. 26AC_DEFUN([gl_WARN_ON_USE_PREPARE], 27[ 28 m4_ifdef([gl_POSIXCHECK], 29 [m4_foreach_w([gl_decl], [$2], 30 [AH_TEMPLATE([HAVE_RAW_DECL_]AS_TR_CPP(m4_defn([gl_decl])), 31 [Define to 1 if ]m4_defn([gl_decl])[ is declared even after 32 undefining macros.])])dnl 33dnl FIXME: gl_Symbol must be used unquoted until we can assume 34dnl autoconf 2.64 or newer. 35 for gl_func in m4_flatten([$2]); do 36 AS_VAR_PUSHDEF([gl_Symbol], [gl_cv_have_raw_decl_$gl_func])dnl 37 AC_CACHE_CHECK([whether $gl_func is declared without a macro], 38 gl_Symbol, 39 [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([$1], 40[@%:@undef $gl_func 41 (void) $gl_func;])], 42 [AS_VAR_SET(gl_Symbol, [yes])], [AS_VAR_SET(gl_Symbol, [no])])]) 43 AS_VAR_IF(gl_Symbol, [yes], 44 [AC_DEFINE_UNQUOTED(AS_TR_CPP([HAVE_RAW_DECL_$gl_func]), [1]) 45 dnl shortcut - if the raw declaration exists, then set a cache 46 dnl variable to allow skipping any later AC_CHECK_DECL efforts 47 eval ac_cv_have_decl_$gl_func=yes]) 48 AS_VAR_POPDEF([gl_Symbol])dnl 49 done 50 ]) 51]) 52