1*820c1a8dSHiroo HAYASHI# warn-on-use.m4 serial 9 2*820c1a8dSHiroo HAYASHIdnl Copyright (C) 2010-2021 Free Software Foundation, Inc. 3*820c1a8dSHiroo HAYASHIdnl This file is free software; the Free Software Foundation 4*820c1a8dSHiroo HAYASHIdnl gives unlimited permission to copy and/or distribute it, 5*820c1a8dSHiroo HAYASHIdnl with or without modifications, as long as this notice is preserved. 6*820c1a8dSHiroo HAYASHI 7*820c1a8dSHiroo HAYASHI# gl_WARN_ON_USE_PREPARE(INCLUDES, NAMES) 8*820c1a8dSHiroo HAYASHI# --------------------------------------- 9*820c1a8dSHiroo HAYASHI# If the module 'posixcheck' is in use: 10*820c1a8dSHiroo HAYASHI# 11*820c1a8dSHiroo HAYASHI# For each whitespace-separated element in the list of NAMES, define 12*820c1a8dSHiroo HAYASHI# HAVE_RAW_DECL_name if the function has a declaration among INCLUDES 13*820c1a8dSHiroo HAYASHI# even after being undefined as a macro. 14*820c1a8dSHiroo HAYASHI# 15*820c1a8dSHiroo HAYASHI# See warn-on-use.h for some hints on how to poison function names, as 16*820c1a8dSHiroo HAYASHI# well as ideas on poisoning global variables and macros. NAMES may 17*820c1a8dSHiroo HAYASHI# include global variables, but remember that only functions work with 18*820c1a8dSHiroo HAYASHI# _GL_WARN_ON_USE. Typically, INCLUDES only needs to list a single 19*820c1a8dSHiroo HAYASHI# header, but if the replacement header pulls in other headers because 20*820c1a8dSHiroo HAYASHI# some systems declare functions in the wrong header, then INCLUDES 21*820c1a8dSHiroo HAYASHI# should do likewise. 22*820c1a8dSHiroo HAYASHI# 23*820c1a8dSHiroo HAYASHI# It is generally safe to assume declarations for functions declared 24*820c1a8dSHiroo HAYASHI# in the intersection of C89 and C11 (such as printf) without 25*820c1a8dSHiroo HAYASHI# needing gl_WARN_ON_USE_PREPARE. 26*820c1a8dSHiroo HAYASHIAC_DEFUN([gl_WARN_ON_USE_PREPARE], 27*820c1a8dSHiroo HAYASHI[ 28*820c1a8dSHiroo HAYASHI m4_ifdef([gl_POSIXCHECK], 29*820c1a8dSHiroo HAYASHI [m4_foreach_w([gl_decl], [$2], 30*820c1a8dSHiroo HAYASHI [AH_TEMPLATE([HAVE_RAW_DECL_]AS_TR_CPP(m4_defn([gl_decl])), 31*820c1a8dSHiroo HAYASHI [Define to 1 if ]m4_defn([gl_decl])[ is declared even after 32*820c1a8dSHiroo HAYASHI undefining macros.])])dnl 33*820c1a8dSHiroo HAYASHI for gl_func in m4_flatten([$2]); do 34*820c1a8dSHiroo HAYASHI AS_VAR_PUSHDEF([gl_Symbol], [gl_cv_have_raw_decl_$gl_func])dnl 35*820c1a8dSHiroo HAYASHI AC_CACHE_CHECK([whether $gl_func is declared without a macro], 36*820c1a8dSHiroo HAYASHI [gl_Symbol], 37*820c1a8dSHiroo HAYASHI [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([$1], 38*820c1a8dSHiroo HAYASHI[[#undef $gl_func 39*820c1a8dSHiroo HAYASHI (void) $gl_func;]])], 40*820c1a8dSHiroo HAYASHI [AS_VAR_SET([gl_Symbol], [yes])], [AS_VAR_SET([gl_Symbol], [no])])]) 41*820c1a8dSHiroo HAYASHI AS_VAR_IF([gl_Symbol], [yes], 42*820c1a8dSHiroo HAYASHI [AC_DEFINE_UNQUOTED(AS_TR_CPP([HAVE_RAW_DECL_$gl_func]), [1]) 43*820c1a8dSHiroo HAYASHI dnl shortcut - if the raw declaration exists, then set a cache 44*820c1a8dSHiroo HAYASHI dnl variable to allow skipping any later AC_CHECK_DECL efforts 45*820c1a8dSHiroo HAYASHI eval ac_cv_have_decl_$gl_func=yes]) 46*820c1a8dSHiroo HAYASHI AS_VAR_POPDEF([gl_Symbol])dnl 47*820c1a8dSHiroo HAYASHI done 48*820c1a8dSHiroo HAYASHI ]) 49*820c1a8dSHiroo HAYASHI]) 50