1# warnings.m4 serial 11 2# modified for strace project 3dnl Copyright (C) 2008-2013 Free Software Foundation, Inc. 4dnl This file is free software; the Free Software Foundation 5dnl gives unlimited permission to copy and/or distribute it, 6dnl with or without modifications, as long as this notice is preserved. 7 8dnl From Simon Josefsson 9 10# gl_AS_VAR_APPEND(VAR, VALUE) 11# ---------------------------- 12# Provide the functionality of AS_VAR_APPEND if Autoconf does not have it. 13m4_ifdef([AS_VAR_APPEND], 14[m4_copy([AS_VAR_APPEND], [gl_AS_VAR_APPEND])], 15[m4_define([gl_AS_VAR_APPEND], 16[AS_VAR_SET([$1], [AS_VAR_GET([$1])$2])])]) 17 18 19# gl_COMPILER_OPTION_IF(OPTION, [IF-SUPPORTED], [IF-NOT-SUPPORTED], 20# [PROGRAM = AC_LANG_PROGRAM()]) 21# ----------------------------------------------------------------- 22# Check if the compiler supports OPTION when compiling PROGRAM. 23# 24# FIXME: gl_Warn must be used unquoted until we can assume Autoconf 25# 2.64 or newer. 26AC_DEFUN([gl_COMPILER_OPTION_IF], 27[AS_VAR_PUSHDEF([gl_Flags], _AC_LANG_PREFIX[]FLAGS)dnl 28AS_VAR_PUSHDEF([gl_Warn], [gl_cv_warn_[]gl_Flags[]_$1])dnl 29AS_LITERAL_IF([$1], 30 [m4_pushdef([gl_Positive], m4_bpatsubst([$1], [^-Wno-], [-W]))], 31 [gl_positive="$1" 32case $gl_positive in 33 -Wno-*) gl_positive=-W`expr "X$gl_positive" : 'X-Wno-\(.*\)'` ;; 34esac 35m4_pushdef([gl_Positive], [$gl_positive])])dnl 36AC_CACHE_CHECK([whether $[]_AC_CC[] handles $1], m4_defn([gl_Warn]), [ 37 gl_save_compiler_FLAGS="$gl_Flags" 38 gl_AS_VAR_APPEND(m4_defn([gl_Flags]), 39 [" $gl_unknown_warnings_are_errors ]m4_defn([gl_Positive])["]) 40 AC_LINK_IFELSE([m4_default([$4], [AC_LANG_PROGRAM([])])], 41 [AS_VAR_SET(gl_Warn, [yes])], 42 [AS_VAR_SET(gl_Warn, [no])]) 43 gl_Flags="$gl_save_compiler_FLAGS" 44]) 45AS_VAR_IF(gl_Warn, [yes], [$2], [$3]) 46m4_popdef([gl_Positive])dnl 47AS_VAR_POPDEF([gl_Flags])dnl 48AS_VAR_POPDEF([gl_Warn])dnl 49]) 50 51# gl_UNKNOWN_WARNINGS_ARE_ERRORS 52# ------------------------------ 53# Clang doesn't complain about unknown warning options unless one also 54# specifies -Wunknown-warning-option -Werror. Detect this. 55AC_DEFUN([gl_UNKNOWN_WARNINGS_ARE_ERRORS], 56[AS_IF([test x${gl_unknown_warnings_are_errors+set} = x], 57 [gl_COMPILER_OPTION_IF([-Werror -Wunknown-warning-option], 58 [gl_unknown_warnings_are_errors='-Wunknown-warning-option -Werror'], 59 [gl_unknown_warnings_are_errors=]) 60 ]) 61]) 62 63# gl_WARN_ADD(OPTION, [VARIABLE = WARN_CFLAGS], 64# [PROGRAM = AC_LANG_PROGRAM()]) 65# --------------------------------------------- 66# Adds parameter to WARN_CFLAGS if the compiler supports it when 67# compiling PROGRAM. For example, gl_WARN_ADD([-Wparentheses]). 68# 69# If VARIABLE is a variable name, AC_SUBST it. 70AC_DEFUN([gl_WARN_ADD], 71[gl_UNKNOWN_WARNINGS_ARE_ERRORS 72gl_COMPILER_OPTION_IF([$1], 73 [gl_AS_VAR_APPEND(m4_if([$2], [], [[WARN_CFLAGS]], [[$2]]), [" $1"])], 74 [], 75 [$3]) 76m4_ifval([$2], 77 [AS_LITERAL_IF([$2], [AC_SUBST([$2])])], 78 [AC_SUBST([WARN_CFLAGS])])dnl 79]) 80 81# Local Variables: 82# mode: autoconf 83# End: 84