xref: /netbsd-src/external/gpl3/gdb/dist/gdbsupport/warning.m4 (revision aef5eb5f59cdfe8314f1b5f78ac04eb144e44010)
1dnl Autoconf configure script for GDB, the GNU debugger.
2dnl Copyright (C) 1995-2020 Free Software Foundation, Inc.
3dnl
4dnl This file is part of GDB.
5dnl
6dnl This program is free software; you can redistribute it and/or modify
7dnl it under the terms of the GNU General Public License as published by
8dnl the Free Software Foundation; either version 3 of the License, or
9dnl (at your option) any later version.
10dnl
11dnl This program is distributed in the hope that it will be useful,
12dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
13dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14dnl GNU General Public License for more details.
15dnl
16dnl You should have received a copy of the GNU General Public License
17dnl along with this program.  If not, see <http://www.gnu.org/licenses/>.
18
19AC_DEFUN([AM_GDB_WARNINGS],[
20AC_ARG_ENABLE(werror,
21  AS_HELP_STRING([--enable-werror], [treat compile warnings as errors]),
22  [case "${enableval}" in
23     yes | y) ERROR_ON_WARNING="yes" ;;
24     no | n)  ERROR_ON_WARNING="no" ;;
25     *) AC_MSG_ERROR(bad value ${enableval} for --enable-werror) ;;
26   esac])
27
28# Enable -Werror by default when using gcc.  Turn it off for releases.
29if test "${GCC}" = yes -a -z "${ERROR_ON_WARNING}" && $development; then
30    ERROR_ON_WARNING=yes
31fi
32
33WERROR_CFLAGS=""
34if test "${ERROR_ON_WARNING}" = yes ; then
35    WERROR_CFLAGS="-Werror"
36fi
37
38# The options we'll try to enable.
39build_warnings="-Wall -Wpointer-arith \
40-Wno-unused -Wunused-value -Wunused-variable -Wunused-function \
41-Wno-switch -Wno-char-subscripts \
42-Wempty-body -Wunused-but-set-parameter -Wunused-but-set-variable \
43-Wno-sign-compare -Wno-error=maybe-uninitialized \
44-Wno-mismatched-tags \
45-Wno-error=deprecated-register \
46-Wsuggest-override \
47-Wimplicit-fallthrough=3 \
48-Wduplicated-cond \
49-Wshadow=local \
50-Wdeprecated-copy \
51-Wdeprecated-copy-dtor \
52-Wredundant-move \
53-Wmissing-declarations \
54-Wmissing-prototypes \
55-Wstrict-null-sentinel \
56"
57
58case "${host}" in
59  *-*-mingw32*)
60    # Enable -Wno-format by default when using gcc on mingw since many
61    # GCC versions complain about %I64.
62    build_warnings="$build_warnings -Wno-format" ;;
63  *-*-solaris*)
64    # Solaris 11.4 <python2.7/ceval.h> uses #pragma no_inline that GCC
65    # doesn't understand.
66    build_warnings="$build_warnings -Wno-unknown-pragmas"
67    # Solaris 11 <unistd.h> marks vfork deprecated.
68    build_warnings="$build_warnings -Wno-deprecated-declarations" ;;
69  *)
70    # Note that gcc requires -Wformat for -Wformat-nonliteral to work,
71    # but there's a special case for this below.
72    build_warnings="$build_warnings -Wformat-nonliteral" ;;
73esac
74
75AC_ARG_ENABLE(build-warnings,
76AS_HELP_STRING([--enable-build-warnings], [enable build-time compiler warnings if gcc is used]),
77[case "${enableval}" in
78  yes)	;;
79  no)	build_warnings="-w";;
80  ,*)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
81        build_warnings="${build_warnings} ${t}";;
82  *,)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
83        build_warnings="${t} ${build_warnings}";;
84  *)    build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
85esac
86if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
87  echo "Setting compiler warning flags = $build_warnings" 6>&1
88fi])dnl
89AC_ARG_ENABLE(gdb-build-warnings,
90AS_HELP_STRING([--enable-gdb-build-warnings], [enable GDB specific build-time compiler warnings if gcc is used]),
91[case "${enableval}" in
92  yes)	;;
93  no)	build_warnings="-w";;
94  ,*)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
95        build_warnings="${build_warnings} ${t}";;
96  *,)   t=`echo "${enableval}" | sed -e "s/,/ /g"`
97        build_warnings="${t} ${build_warnings}";;
98  *)    build_warnings=`echo "${enableval}" | sed -e "s/,/ /g"`;;
99esac
100if test x"$silent" != x"yes" && test x"$build_warnings" != x""; then
101  echo "Setting GDB specific compiler warning flags = $build_warnings" 6>&1
102fi])dnl
103
104# The set of warnings supported by a C++ compiler is not the same as
105# of the C compiler.
106AC_LANG_PUSH([C++])
107
108WARN_CFLAGS=""
109if test "x${build_warnings}" != x -a "x$GCC" = xyes
110then
111    AC_MSG_CHECKING(compiler warning flags)
112    # Separate out the -Werror flag as some files just cannot be
113    # compiled with it enabled.
114    for w in ${build_warnings}; do
115	# GCC does not complain about -Wno-unknown-warning.  Invert
116	# and test -Wunknown-warning instead.
117	case $w in
118	-Wno-*)
119		wtest=`echo $w | sed 's/-Wno-/-W/g'` ;;
120        -Wformat-nonliteral)
121		# gcc requires -Wformat before -Wformat-nonliteral
122		# will work, so stick them together.
123		w="-Wformat $w"
124		wtest="$w"
125		;;
126	*)
127		wtest=$w ;;
128	esac
129
130	case $w in
131	-Werr*) WERROR_CFLAGS=-Werror ;;
132	*)
133	    # Check whether GCC accepts it.
134	    saved_CFLAGS="$CFLAGS"
135	    CFLAGS="$CFLAGS -Werror $wtest"
136	    saved_CXXFLAGS="$CXXFLAGS"
137	    CXXFLAGS="$CXXFLAGS -Werror $wtest"
138	    if test "x$w" = "x-Wunused-variable"; then
139	      # Check for https://gcc.gnu.org/bugzilla/show_bug.cgi?id=38958,
140	      # fixed in GCC 4.9.  This test is derived from the gdb
141	      # source code that triggered this bug in GCC.
142	      AC_TRY_COMPILE(
143	        [struct scoped_restore_base {};
144                 struct scoped_restore_tmpl : public scoped_restore_base {
145		   ~scoped_restore_tmpl() {}
146		 };],
147		[const scoped_restore_base &b = scoped_restore_tmpl();],
148		WARN_CFLAGS="${WARN_CFLAGS} $w",)
149	    else
150	      AC_TRY_COMPILE([],[],WARN_CFLAGS="${WARN_CFLAGS} $w",)
151	    fi
152	    CFLAGS="$saved_CFLAGS"
153	    CXXFLAGS="$saved_CXXFLAGS"
154	esac
155    done
156    AC_MSG_RESULT(${WARN_CFLAGS} ${WERROR_CFLAGS})
157fi
158AC_SUBST(WARN_CFLAGS)
159AC_SUBST(WERROR_CFLAGS)
160
161AC_LANG_POP([C++])
162])
163