~mdw / secnet / blame
| Commit | Line | Data |
|---|---|---|
| 3b83c932 SE |
1 | dnl @synopsis AC_PROG_CC_NO_WRITEABLE_STRINGS(substvar [,hard]) |
| 2 | dnl | |
| 3 | dnl Try to find a compiler option that warns when a stringliteral is | |
| 4 | dnl used in a place that could potentially modify the address. This | |
| 5 | dnl should warn on giving an stringliteral to a function that asks of | |
| 6 | dnl a non-const-modified char-pointer. | |
| 7 | dnl | |
| 8 | dnl The sanity check is done by looking at string.h which has a set | |
| 9 | dnl of strcpy definitions that should be defined with const-modifiers | |
| 10 | dnl to not emit a warning in all so many places. | |
| 11 | dnl | |
| 12 | dnl Currently this macro knows about GCC. | |
| 13 | dnl hopefully will evolve to use: Solaris C compiler, | |
| 14 | dnl Digital Unix C compiler, C for AIX Compiler, HP-UX C compiler, | |
| 15 | dnl and IRIX C compiler. | |
| 16 | dnl | |
| 17 | dnl @version $Id: ac_prog_cc_no_writeable_strings.m4,v 1.1 2002/02/20 16:18:18 steve Exp $ | |
| 18 | dnl @author Guido Draheim <guidod@gmx.de> | |
| 19 | dnl | |
| 20 | AC_DEFUN([AC_PROG_CC_NO_WRITEABLE_STRINGS], [ | |
| 21 | pushdef([CV],ac_cv_prog_cc_no_writeable_strings)dnl | |
| 22 | hard=$2 | |
| 23 | if test -z "$hard"; then | |
| 24 | msg="C to warn about writing to stringliterals" | |
| 25 | else | |
| 26 | msg="C to prohibit any write to stringliterals" | |
| 27 | fi | |
| 28 | AC_CACHE_CHECK($msg, CV, [ | |
| 29 | cat > conftest.c <<EOF | |
| 30 | #include <string.h> | |
| 31 | int main (void) | |
| 32 | { | |
| 33 | char test[[16]]; | |
| 34 | if (strcpy (test, "test")) return 0; | |
| 35 | return 1; | |
| 36 | } | |
| 37 | EOF | |
| 38 | dnl GCC | |
| 39 | if test "$GCC" = "yes"; | |
| 40 | then | |
| 41 | if test -z "$hard"; then | |
| 42 | CV="-Wwrite-strings" | |
| 43 | else | |
| 44 | CV="-fno-writable-strings -Wwrite-strings" | |
| 45 | fi | |
| 46 | ||
| 47 | if test -n "`${CC-cc} -c $CV conftest.c 2>&1`" ; then | |
| 48 | CV="suppressed: string.h" | |
| 49 | fi | |
| 50 | ||
| 51 | dnl Solaris C compiler | |
| 52 | elif $CC -flags 2>&1 | grep "Xc.*strict ANSI C" > /dev/null 2>&1 && | |
| 53 | $CC -c -xstrconst conftest.c > /dev/null 2>&1 && | |
| 54 | test -f conftest.o | |
| 55 | then | |
| 56 | # strings go into readonly segment | |
| 57 | CV="-xstrconst" | |
| 58 | ||
| 59 | rm conftest.o | |
| 60 | if test -n "`${CC-cc} -c $CV conftest.c 2>&1`" ; then | |
| 61 | CV="suppressed: string.h" | |
| 62 | fi | |
| 63 | ||
| 64 | dnl HP-UX C compiler | |
| 65 | elif $CC > /dev/null 2>&1 && | |
| 66 | $CC -c +ESlit conftest.c > /dev/null 2>&1 && | |
| 67 | test -f conftest.o | |
| 68 | then | |
| 69 | # strings go into readonly segment | |
| 70 | CV="+ESlit" | |
| 71 | ||
| 72 | rm conftest.o | |
| 73 | if test -n "`${CC-cc} -c $CV conftest.c 2>&1`" ; then | |
| 74 | CV="suppressed: string.h" | |
| 75 | fi | |
| 76 | ||
| 77 | dnl Digital Unix C compiler | |
| 78 | elif ! $CC > /dev/null 2>&1 && | |
| 79 | $CC -c -readonly_strings conftest.c > /dev/null 2>&1 && | |
| 80 | test -f conftest.o | |
| 81 | then | |
| 82 | # strings go into readonly segment | |
| 83 | CV="-readonly_strings" | |
| 84 | ||
| 85 | rm conftest.o | |
| 86 | if test -n "`${CC-cc} -c $CV conftest.c 2>&1`" ; then | |
| 87 | CV="suppressed: string.h" | |
| 88 | fi | |
| 89 | ||
| 90 | dnl C for AIX Compiler | |
| 91 | ||
| 92 | dnl IRIX C compiler | |
| 93 | # -use_readonly_const is the default for IRIX C, | |
| 94 | # puts them into .rodata, but they are copied later. | |
| 95 | # need to be "-G0 -rdatashared" for strictmode but | |
| 96 | # I am not sure what effect that has really. | |
| 97 | ||
| 98 | fi | |
| 99 | rm -f conftest.* | |
| 100 | ]) | |
| 101 | if test -z "[$]$1" ; then | |
| 102 | if test -n "$CV" ; then | |
| 103 | case "$CV" in | |
| 104 | suppressed*) $1="" ;; # known but suppressed | |
| 105 | *) $1="$CV" ;; | |
| 106 | esac | |
| 107 | fi | |
| 108 | fi | |
| 109 | AC_SUBST($1) | |
| 110 | popdef([CV])dnl | |
| 111 | ]) | |
| 112 | ||
| 113 |