diff options
Diffstat (limited to 'gl')
| -rw-r--r-- | gl/m4/warn-on-use.m4 | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/gl/m4/warn-on-use.m4 b/gl/m4/warn-on-use.m4 new file mode 100644 index 0000000000..ab46422bab --- /dev/null +++ b/gl/m4/warn-on-use.m4 @@ -0,0 +1,45 @@ +# warn-on-use.m4 serial 1 +dnl Copyright (C) 2010 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. + +# gl_WARN_ON_USE_PREPARE(INCLUDES, NAMES) +# --------------------------------------- +# For each whitespace-separated element in the list of NAMES, define +# HAVE_RAW_DECL_name if the function has a declaration among INCLUDES +# even after being undefined as a macro. +# +# See warn-on-use.h for some hints on how to poison function names, as +# well as ideas on poisoning global variables and macros. NAMES may +# include global variables, but remember that only functions work with +# _GL_WARN_ON_USE. Typically, INCLUDES only needs to list a single +# header, but if the replacement header pulls in other headers because +# some systems declare functions in the wrong header, then INCLUDES +# should do likewise. +# +# If you assume C89, then it is generally safe to assume declarations +# for functions declared in that standard (such as gets) without +# needing gl_WARN_ON_USE_PREPARE. +AC_DEFUN([gl_WARN_ON_USE_PREPARE], +[ + m4_foreach_w([gl_decl], [$2], + [AH_TEMPLATE([HAVE_RAW_DECL_]AS_TR_CPP(m4_defn([gl_decl])), + [Define to 1 if ]m4_defn([gl_decl])[ is declared even after + undefining macros.])])dnl + for gl_func in m4_flatten([$2]); do + AS_VAR_PUSHDEF([gl_Symbol], [gl_cv_have_raw_decl_$gl_func])dnl + AC_CACHE_CHECK([whether $gl_func is declared without a macro], + [gl_Symbol], + [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([$1], +[@%:@undef $gl_func + (void) $gl_func;])], + [AS_VAR_SET([gl_Symbol], [yes])], [AS_VAR_SET([gl_Symbol], [no])])]) + AS_VAR_IF([gl_Symbol], [yes], + [AC_DEFINE_UNQUOTED(AS_TR_CPP([HAVE_RAW_DECL_$gl_func]), [1]) + dnl shortcut - if the raw declaration exists, then set a cache + dnl variable to allow skipping any later AC_CHECK_DECL efforts + eval ac_cv_have_decl_$gl_func=yes]) + AS_VAR_POPDEF([gl_Symbol])dnl + done +]) |