warnings.m4 4.12 KB
Newer Older
Paul Eggert's avatar
Paul Eggert committed
1
# warnings.m4 serial 14
Paul Eggert's avatar
Paul Eggert committed
2
dnl Copyright (C) 2008-2019 Free Software Foundation, Inc.
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
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.

dnl From Simon Josefsson

# gl_AS_VAR_APPEND(VAR, VALUE)
# ----------------------------
# Provide the functionality of AS_VAR_APPEND if Autoconf does not have it.
m4_ifdef([AS_VAR_APPEND],
[m4_copy([AS_VAR_APPEND], [gl_AS_VAR_APPEND])],
[m4_define([gl_AS_VAR_APPEND],
[AS_VAR_SET([$1], [AS_VAR_GET([$1])$2])])])


Paul Eggert's avatar
Paul Eggert committed
18 19 20 21
# gl_COMPILER_OPTION_IF(OPTION, [IF-SUPPORTED], [IF-NOT-SUPPORTED],
#                       [PROGRAM = AC_LANG_PROGRAM()])
# -----------------------------------------------------------------
# Check if the compiler supports OPTION when compiling PROGRAM.
22
#
Paul Eggert's avatar
Paul Eggert committed
23
# The effects of this macro depend on the current language (_AC_LANG).
Paul Eggert's avatar
Paul Eggert committed
24
AC_DEFUN([gl_COMPILER_OPTION_IF],
Paul Eggert's avatar
Paul Eggert committed
25 26 27 28
[
dnl FIXME: gl_Warn must be used unquoted until we can assume Autoconf
dnl 2.64 or newer.
AS_VAR_PUSHDEF([gl_Warn], [gl_cv_warn_[]_AC_LANG_ABBREV[]_$1])dnl
29
AS_VAR_PUSHDEF([gl_Flags], [_AC_LANG_PREFIX[]FLAGS])dnl
Paul Eggert's avatar
Paul Eggert committed
30 31 32 33 34 35 36
AS_LITERAL_IF([$1],
  [m4_pushdef([gl_Positive], m4_bpatsubst([$1], [^-Wno-], [-W]))],
  [gl_positive="$1"
case $gl_positive in
  -Wno-*) gl_positive=-W`expr "X$gl_positive" : 'X-Wno-\(.*\)'` ;;
esac
m4_pushdef([gl_Positive], [$gl_positive])])dnl
37 38
AC_CACHE_CHECK([whether _AC_LANG compiler handles $1], m4_defn([gl_Warn]), [
  gl_save_compiler_FLAGS="$gl_Flags"
Paul Eggert's avatar
Paul Eggert committed
39 40
  gl_AS_VAR_APPEND(m4_defn([gl_Flags]),
    [" $gl_unknown_warnings_are_errors ]m4_defn([gl_Positive])["])
Paul Eggert's avatar
Paul Eggert committed
41 42 43
  AC_LINK_IFELSE([m4_default([$4], [AC_LANG_PROGRAM([])])],
                 [AS_VAR_SET(gl_Warn, [yes])],
                 [AS_VAR_SET(gl_Warn, [no])])
44 45
  gl_Flags="$gl_save_compiler_FLAGS"
])
Paul Eggert's avatar
Paul Eggert committed
46
AS_VAR_IF(gl_Warn, [yes], [$2], [$3])
Paul Eggert's avatar
Paul Eggert committed
47
m4_popdef([gl_Positive])dnl
48 49 50
AS_VAR_POPDEF([gl_Flags])dnl
AS_VAR_POPDEF([gl_Warn])dnl
])
Paul Eggert's avatar
Paul Eggert committed
51

Paul Eggert's avatar
Paul Eggert committed
52 53 54 55
# gl_UNKNOWN_WARNINGS_ARE_ERRORS
# ------------------------------
# Clang doesn't complain about unknown warning options unless one also
# specifies -Wunknown-warning-option -Werror.  Detect this.
Paul Eggert's avatar
Paul Eggert committed
56 57
#
# The effects of this macro depend on the current language (_AC_LANG).
Paul Eggert's avatar
Paul Eggert committed
58
AC_DEFUN([gl_UNKNOWN_WARNINGS_ARE_ERRORS],
Paul Eggert's avatar
Paul Eggert committed
59 60 61
[_AC_LANG_DISPATCH([$0], _AC_LANG, $@)])

# Specialization for _AC_LANG = C. This macro can be AC_REQUIREd.
Paul Eggert's avatar
Paul Eggert committed
62 63
# Use of m4_defun rather than AC_DEFUN works around a bug in autoconf < 2.63b.
m4_defun([gl_UNKNOWN_WARNINGS_ARE_ERRORS(C)],
Paul Eggert's avatar
Paul Eggert committed
64 65 66 67 68 69 70
[
  AC_LANG_PUSH([C])
  gl_UNKNOWN_WARNINGS_ARE_ERRORS_IMPL
  AC_LANG_POP([C])
])

# Specialization for _AC_LANG = C++. This macro can be AC_REQUIREd.
Paul Eggert's avatar
Paul Eggert committed
71 72
# Use of m4_defun rather than AC_DEFUN works around a bug in autoconf < 2.63b.
m4_defun([gl_UNKNOWN_WARNINGS_ARE_ERRORS(C++)],
Paul Eggert's avatar
Paul Eggert committed
73 74 75 76 77 78
[
  AC_LANG_PUSH([C++])
  gl_UNKNOWN_WARNINGS_ARE_ERRORS_IMPL
  AC_LANG_POP([C++])
])

Paul Eggert's avatar
Paul Eggert committed
79 80 81 82 83 84 85 86 87
# Specialization for _AC_LANG = Objective C. This macro can be AC_REQUIREd.
# Use of m4_defun rather than AC_DEFUN works around a bug in autoconf < 2.63b.
m4_defun([gl_UNKNOWN_WARNINGS_ARE_ERRORS(Objective C)],
[
  AC_LANG_PUSH([Objective C])
  gl_UNKNOWN_WARNINGS_ARE_ERRORS_IMPL
  AC_LANG_POP([Objective C])
])

Paul Eggert's avatar
Paul Eggert committed
88
AC_DEFUN([gl_UNKNOWN_WARNINGS_ARE_ERRORS_IMPL],
Paul Eggert's avatar
Paul Eggert committed
89 90 91
[gl_COMPILER_OPTION_IF([-Werror -Wunknown-warning-option],
   [gl_unknown_warnings_are_errors='-Wunknown-warning-option -Werror'],
   [gl_unknown_warnings_are_errors=])])
Paul Eggert's avatar
Paul Eggert committed
92

Paul Eggert's avatar
Paul Eggert committed
93
# gl_WARN_ADD(OPTION, [VARIABLE = WARN_CFLAGS/WARN_CXXFLAGS],
Paul Eggert's avatar
Paul Eggert committed
94
#             [PROGRAM = AC_LANG_PROGRAM()])
Paul Eggert's avatar
Paul Eggert committed
95 96 97
# -----------------------------------------------------------
# Adds parameter to WARN_CFLAGS/WARN_CXXFLAGS if the compiler supports it
# when compiling PROGRAM.  For example, gl_WARN_ADD([-Wparentheses]).
Paul Eggert's avatar
Paul Eggert committed
98 99
#
# If VARIABLE is a variable name, AC_SUBST it.
Paul Eggert's avatar
Paul Eggert committed
100 101
#
# The effects of this macro depend on the current language (_AC_LANG).
Paul Eggert's avatar
Paul Eggert committed
102
AC_DEFUN([gl_WARN_ADD],
Paul Eggert's avatar
Paul Eggert committed
103
[AC_REQUIRE([gl_UNKNOWN_WARNINGS_ARE_ERRORS(]_AC_LANG[)])
Paul Eggert's avatar
Paul Eggert committed
104
gl_COMPILER_OPTION_IF([$1],
Paul Eggert's avatar
Paul Eggert committed
105
  [gl_AS_VAR_APPEND(m4_if([$2], [], [[WARN_]_AC_LANG_PREFIX[FLAGS]], [[$2]]), [" $1"])],
Paul Eggert's avatar
Paul Eggert committed
106 107 108 109
  [],
  [$3])
m4_ifval([$2],
         [AS_LITERAL_IF([$2], [AC_SUBST([$2])])],
Paul Eggert's avatar
Paul Eggert committed
110
         [AC_SUBST([WARN_]_AC_LANG_PREFIX[FLAGS])])dnl
Paul Eggert's avatar
Paul Eggert committed
111 112 113 114 115
])

# Local Variables:
# mode: autoconf
# End: