aclocal.m4 revision 89857
1dnl See whether strncmp reads past the end of its string parameters. 2dnl On some versions of SunOS4 at least, strncmp reads a word at a time 3dnl but erroneously reads past the end of strings. This can cause 4dnl a SEGV in some cases. 5AC_DEFUN(libiberty_AC_FUNC_STRNCMP, 6[AC_REQUIRE([AC_FUNC_MMAP]) 7AC_CACHE_CHECK([for working strncmp], ac_cv_func_strncmp_works, 8[AC_TRY_RUN([ 9/* Test by Jim Wilson and Kaveh Ghazi. 10 Check whether strncmp reads past the end of its string parameters. */ 11#include <sys/types.h> 12 13#ifdef HAVE_FCNTL_H 14#include <fcntl.h> 15#endif 16 17#ifdef HAVE_SYS_MMAN_H 18#include <sys/mman.h> 19#endif 20 21#ifndef MAP_ANON 22#ifdef MAP_ANONYMOUS 23#define MAP_ANON MAP_ANONYMOUS 24#else 25#define MAP_ANON MAP_FILE 26#endif 27#endif 28 29#ifndef MAP_FILE 30#define MAP_FILE 0 31#endif 32#ifndef O_RDONLY 33#define O_RDONLY 0 34#endif 35 36#define MAP_LEN 0x10000 37 38main () 39{ 40#if defined(HAVE_MMAP) || defined(HAVE_MMAP_ANYWHERE) 41 char *p; 42 int dev_zero; 43 44 dev_zero = open ("/dev/zero", O_RDONLY); 45 if (dev_zero < 0) 46 exit (1); 47 48 p = (char *) mmap (0, MAP_LEN, PROT_READ|PROT_WRITE, 49 MAP_ANON|MAP_PRIVATE, dev_zero, 0); 50 if (p == (char *)-1) 51 p = (char *) mmap (0, MAP_LEN, PROT_READ|PROT_WRITE, 52 MAP_ANON|MAP_PRIVATE, -1, 0); 53 if (p == (char *)-1) 54 exit (2); 55 else 56 { 57 char *string = "__si_type_info"; 58 char *q = (char *) p + MAP_LEN - strlen (string) - 2; 59 char *r = (char *) p + 0xe; 60 61 strcpy (q, string); 62 strcpy (r, string); 63 strncmp (r, q, 14); 64 } 65#endif /* HAVE_MMAP || HAVE_MMAP_ANYWHERE */ 66 exit (0); 67} 68], ac_cv_func_strncmp_works=yes, ac_cv_func_strncmp_works=no, 69 ac_cv_func_strncmp_works=no) 70rm -f core core.* *.core]) 71if test $ac_cv_func_strncmp_works = no ; then 72 LIBOBJS="$LIBOBJS strncmp.o" 73fi 74]) 75 76dnl See if errno must be declared even when <errno.h> is included. 77AC_DEFUN(libiberty_AC_DECLARE_ERRNO, 78[AC_CACHE_CHECK(whether errno must be declared, libiberty_cv_declare_errno, 79[AC_TRY_COMPILE( 80[#include <errno.h>], 81[int x = errno;], 82libiberty_cv_declare_errno=no, 83libiberty_cv_declare_errno=yes)]) 84if test $libiberty_cv_declare_errno = yes 85then AC_DEFINE(NEED_DECLARATION_ERRNO, 1, 86 [Define if errno must be declared even when <errno.h> is included.]) 87fi 88]) 89 90# FIXME: We temporarily define our own version of AC_PROG_CC. This is 91# copied from autoconf 2.12, but does not call AC_PROG_CC_WORKS. We 92# are probably using a cross compiler, which will not be able to fully 93# link an executable. This should really be fixed in autoconf 94# itself. 95 96AC_DEFUN(LIB_AC_PROG_CC, 97[AC_BEFORE([$0], [AC_PROG_CPP])dnl 98AC_PROVIDE([AC_PROG_CC]) 99AC_CHECK_PROG(CC, gcc, gcc) 100if test -z "$CC"; then 101 AC_CHECK_PROG(CC, cc, cc, , , /usr/ucb/cc) 102 test -z "$CC" && AC_MSG_ERROR([no acceptable cc found in \$PATH]) 103fi 104 105AC_PROG_CC_GNU 106 107if test $ac_cv_prog_gcc = yes; then 108 GCC=yes 109 ac_libiberty_warn_cflags='-W -Wall -Wtraditional -pedantic' 110dnl Check whether -g works, even if CFLAGS is set, in case the package 111dnl plays around with CFLAGS (such as to build both debugging and 112dnl normal versions of a library), tasteless as that idea is. 113 ac_test_CFLAGS="${CFLAGS+set}" 114 ac_save_CFLAGS="$CFLAGS" 115 CFLAGS= 116 AC_PROG_CC_G 117 if test "$ac_test_CFLAGS" = set; then 118 CFLAGS="$ac_save_CFLAGS" 119 elif test $ac_cv_prog_cc_g = yes; then 120 CFLAGS="-g -O2" 121 else 122 CFLAGS="-O2" 123 fi 124else 125 GCC= 126 ac_libiberty_warn_cflags= 127 test "${CFLAGS+set}" = set || CFLAGS="-g" 128fi 129AC_SUBST(ac_libiberty_warn_cflags) 130]) 131 132# Work around a bug in autoheader. This can go away when we switch to 133# autoconf >2.50. The use of define instead of AC_DEFUN is 134# deliberate. 135define(AC_DEFINE_NOAUTOHEADER, 136[cat >> confdefs.h <<\EOF 137[#define] $1 ifelse($#, 2, [$2], $#, 3, [$2], 1) 138EOF 139]) 140 141# We always want a C version of alloca() compiled into libiberty, 142# because native-compiler support for the real alloca is so !@#$% 143# unreliable that GCC has decided to use it only when being compiled 144# by GCC. This is the part of AC_FUNC_ALLOCA that calculates the 145# information alloca.c needs. 146AC_DEFUN(libiberty_AC_FUNC_C_ALLOCA, 147[AC_CACHE_CHECK(whether alloca needs Cray hooks, ac_cv_os_cray, 148[AC_EGREP_CPP(webecray, 149[#if defined(CRAY) && ! defined(CRAY2) 150webecray 151#else 152wenotbecray 153#endif 154], ac_cv_os_cray=yes, ac_cv_os_cray=no)]) 155if test $ac_cv_os_cray = yes; then 156 for ac_func in _getb67 GETB67 getb67; do 157 AC_CHECK_FUNC($ac_func, 158 [AC_DEFINE_UNQUOTED(CRAY_STACKSEG_END, $ac_func, 159 [Define to one of _getb67, GETB67, getb67 for Cray-2 and Cray-YMP 160 systems. This function is required for alloca.c support on those 161 systems.]) break]) 162 done 163fi 164 165AC_CACHE_CHECK(stack direction for C alloca, ac_cv_c_stack_direction, 166[AC_TRY_RUN([find_stack_direction () 167{ 168 static char *addr = 0; 169 auto char dummy; 170 if (addr == 0) 171 { 172 addr = &dummy; 173 return find_stack_direction (); 174 } 175 else 176 return (&dummy > addr) ? 1 : -1; 177} 178main () 179{ 180 exit (find_stack_direction() < 0); 181}], 182 ac_cv_c_stack_direction=1, 183 ac_cv_c_stack_direction=-1, 184 ac_cv_c_stack_direction=0)]) 185AC_DEFINE_UNQUOTED(STACK_DIRECTION, $ac_cv_c_stack_direction, 186 [Define if you know the direction of stack growth for your system; 187 otherwise it will be automatically deduced at run-time. 188 STACK_DIRECTION > 0 => grows toward higher addresses 189 STACK_DIRECTION < 0 => grows toward lower addresses 190 STACK_DIRECTION = 0 => direction of growth unknown]) 191]) 192