1 # warnings.m4 serial 11
2 # modified for strace project
3 dnl Copyright (C) 2008-2013 Free Software Foundation, Inc.
4 dnl This file is free software; the Free Software Foundation
5 dnl gives unlimited permission to copy and/or distribute it,
6 dnl with or without modifications, as long as this notice is preserved.
8 dnl From Simon Josefsson
10 # gl_AS_VAR_APPEND(VAR, VALUE)
11 # ----------------------------
12 # Provide the functionality of AS_VAR_APPEND if Autoconf does not have it.
13 m4_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])])])
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.
24 # FIXME: gl_Warn must be used unquoted until we can assume Autoconf
26 AC_DEFUN([gl_COMPILER_OPTION_IF],
27 [AS_VAR_PUSHDEF([gl_Flags], _AC_LANG_PREFIX[]FLAGS)dnl
28 AS_VAR_PUSHDEF([gl_Warn], [gl_cv_warn_[]gl_Flags[]_$1])dnl
30 [m4_pushdef([gl_Positive], m4_bpatsubst([$1], [^-Wno-], [-W]))],
33 -Wno-*) gl_positive=-W`expr "X$gl_positive" : 'X-Wno-\(.*\)'` ;;
35 m4_pushdef([gl_Positive], [$gl_positive])])dnl
36 AC_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"
45 AS_VAR_IF(gl_Warn, [yes], [$2], [$3])
46 m4_popdef([gl_Positive])dnl
47 AS_VAR_POPDEF([gl_Flags])dnl
48 AS_VAR_POPDEF([gl_Warn])dnl
51 # gl_UNKNOWN_WARNINGS_ARE_ERRORS
52 # ------------------------------
53 # Clang doesn't complain about unknown warning options unless one also
54 # specifies -Wunknown-warning-option -Werror. Detect this.
55 AC_DEFUN([gl_UNKNOWN_WARNINGS_ARE_ERRORS],
56 [AS_IF([test x${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=])
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]).
69 # If VARIABLE is a variable name, AC_SUBST it.
70 AC_DEFUN([gl_WARN_ADD],
71 [gl_UNKNOWN_WARNINGS_ARE_ERRORS
72 gl_COMPILER_OPTION_IF([$1],
73 [gl_AS_VAR_APPEND(m4_if([$2], [], [[WARN_CFLAGS]], [[$2]]), [" $1"])],
77 [AS_LITERAL_IF([$2], [AC_SUBST([$2])])],
78 [AC_SUBST([WARN_CFLAGS])])dnl