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bison: avoid warnings from static code analysis
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1 # Sanity test a C compiler.
2
3 # Copyright (C) 2006, 2009-2015 Free Software Foundation, Inc.
4 #
5 # This program is free software: you can redistribute it and/or modify
6 # it under the terms of the GNU General Public License as published by
7 # the Free Software Foundation, either version 3 of the License, or
8 # (at your option) any later version.
9 #
10 # This program is distributed in the hope that it will be useful,
11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 # GNU General Public License for more details.
14 #
15 # You should have received a copy of the GNU General Public License
16 # along with this program. If not, see <http://www.gnu.org/licenses/>.
17
18 # Written by Paul Eggert.
19
20 AC_DEFUN([BISON_TEST_FOR_WORKING_C_COMPILER], [
21 AC_COMPILE_IFELSE(
22 [AC_LANG_PROGRAM(
23 [[#include <limits.h>
24 int test_array[CHAR_BIT];]])],
25 [],
26 [AC_MSG_FAILURE([cannot compile a simple C program])])
27 AC_SUBST([BISON_C_WORKS], [:])
28 ])
29
30 # BISON_CHECK_WITH_POSIXLY_CORRECT(CODE)
31 # --------------------------------------
32 # Run the Autoconf CODE with POSIXLY_CORRECT set to 1, and restored to
33 # its initial value afterwards.
34 AC_DEFUN([BISON_CHECK_WITH_POSIXLY_CORRECT],
35 [gl_awk_probe='BEGIN { if ("POSIXLY_CORRECT" in ENVIRON) print "x" }'
36 case ${POSIXLY_CORRECT+x}`$AWK "$gl_awk_probe" </dev/null` in
37 xx) gl_had_POSIXLY_CORRECT=exported ;;
38 x) gl_had_POSIXLY_CORRECT=yes ;;
39 *) gl_had_POSIXLY_CORRECT= ;;
40 esac
41 POSIXLY_CORRECT=1
42 export POSIXLY_CORRECT
43 $1
44 case $gl_had_POSIXLY_CORRECT in
45 exported) ;;
46 yes) AS_UNSET([POSIXLY_CORRECT]); POSIXLY_CORRECT=1 ;;
47 *) AS_UNSET([POSIXLY_CORRECT]) ;;
48 esac
49 ])
50
51 # BISON_LANG_COMPILER_POSIXLY_CORRECT
52 # -----------------------------------
53 # Whether the compiler for the current language supports -g in
54 # POSIXLY_CORRECT mode. clang-2.9 on OS X does not, because
55 # "clang-mp-2.9 -o test -g test.c" launches "/usr/bin/dsymutil test -o
56 # test.dSYM" which fails with "error: unable to open executable '-o'".
57 #
58 # Sets <LANG>_COMPILER_POSIXLY_CORRECT to true/false.
59 AC_DEFUN([BISON_LANG_COMPILER_POSIXLY_CORRECT],
60 [AC_CACHE_CHECK([whether $_AC_CC supports POSIXLY_CORRECT=1],
61 [bison_cv_[]_AC_LANG_ABBREV[]_supports_posixly_correct],
62 [BISON_CHECK_WITH_POSIXLY_CORRECT(
63 [AC_LINK_IFELSE([AC_LANG_PROGRAM],
64 [bison_cv_[]_AC_LANG_ABBREV[]_supports_posixly_correct=yes],
65 [bison_cv_[]_AC_LANG_ABBREV[]_supports_posixly_correct=no])])])
66 case $bison_cv_[]_AC_LANG_ABBREV[]_supports_posixly_correct in
67 yes) AC_SUBST(_AC_LANG_PREFIX[_COMPILER_POSIXLY_CORRECT], [true]) ;;
68 no) AC_SUBST(_AC_LANG_PREFIX[_COMPILER_POSIXLY_CORRECT], [false]);;
69 esac
70 ])
71
72 # BISON_C_COMPILER_POSIXLY_CORRECT
73 # --------------------------------
74 # Whether the C compiler supports -g in POSIXLY_CORRECT mode.
75 AC_DEFUN([BISON_C_COMPILER_POSIXLY_CORRECT],
76 [AC_LANG_PUSH([C])
77 BISON_LANG_COMPILER_POSIXLY_CORRECT
78 AC_LANG_POP([C])
79 ])