+++ /dev/null
-dnl AC_CHECK_UCONTEXT: Check whether ucontext are working
-
-dnl Most of the code is stolen from the GNU pth autoconf macros by
-dnl Ralf S. Engelschall. As
-dnl # ``"Reuse an expert's code" is the right
-dnl # advice for most people. But it's a useless
-dnl # advice for the experts writing the code
-dnl # in the first place.'
-dnl # -- Dan J. Bernstein
-dnl
-dnl OK, you're definitely the expert on this point... :)
-
-dnl ##
-dnl ## Display Configuration Headers
-dnl ##
-dnl ## configure.ac:
-dnl ## AC_MSG_PART(<text>)
-dnl ##
-
-m4_define(AC_MSG_PART,[dnl
-if test ".$enable_subdir" != .yes; then
- AC_MSG_RESULT()
- AC_MSG_RESULT(${TB}$1:${TN})
-fi
-])dnl
-
-dnl ##
-dnl ## Display a message under --verbose
-dnl ##
-dnl ## configure.ac:
-dnl ## AC_MSG_VERBOSE(<text>)
-dnl ##
-
-m4_define(AC_MSG_VERBOSE,[dnl
-if test ".$verbose" = .yes; then
- AC_MSG_RESULT([ $1])
-fi
-])
-
-dnl ##
-dnl ## Do not display message for a command
-dnl ##
-dnl ## configure.ac:
-dnl ## AC_MSG_SILENT(...)
-dnl ##
-
-m4_define(AC_FD_TMP, 9)
-m4_define(AC_MSG_SILENT,[dnl
-exec AC_FD_TMP>&AC_FD_MSG AC_FD_MSG>/dev/null
-$1
-exec AC_FD_MSG>&AC_FD_TMP AC_FD_TMP>&-
-])
-
-dnl ##
-dnl ## Check for direction of stack growth
-dnl ##
-dnl ## configure.ac:
-dnl ## AC_CHECK_STACKGROWTH(<define>)
-dnl ## acconfig.h:
-dnl ## #undef <define>
-dnl ## source.c:
-dnl ## #include "config.h"
-dnl ## #if <define> < 0
-dnl ## ...stack grow down...
-dnl ## #else
-dnl ## ...stack grow up...
-dnl ## #endif
-dnl ##
-
-AC_DEFUN([AC_CHECK_STACKGROWTH],[dnl
-AC_MSG_CHECKING(for direction of stack growth)
-AC_CACHE_VAL(ac_cv_check_stackgrowth, [
-cross_compiling=no
-AC_TRY_RUN(
-changequote(<<, >>)dnl
-<<
-#include <stdio.h>
-#include <stdlib.h>
-static int iterate = 10;
-static int growsdown(int *x)
-{
- auto int y;
- y = (x > &y);
- if (--iterate > 0)
- y = growsdown(&y);
- if (y != (x > &y))
- exit(1);
- return y;
-}
-int main(int argc, char *argv[])
-{
- FILE *f;
- auto int x;
- if ((f = fopen("conftestval", "w")) == NULL)
- exit(1);
- fprintf(f, "%s\n", growsdown(&x) ? "down" : "up");;
- fclose(f);
- exit(0);
-}
->>
-changequote([, ])dnl
-,
-ac_cv_check_stackgrowth=`cat conftestval`,
-ac_cv_check_stackgrowth=down,
-ac_cv_check_stackgrowth=down
-)dnl
-])dnl
-AC_MSG_RESULT([$ac_cv_check_stackgrowth])
-if test ".$ac_cv_check_stackgrowth" = ".down"; then
- val="-1"
-else
- val="+1"
-fi
-AC_DEFINE_UNQUOTED($1, $val, [define for stack growth])
-])
-
-dnl ##
-dnl ## Check whether SVR4/SUSv2 makecontext(2), swapcontext(2) and
-dnl ## friends can be used for user-space context switching
-dnl ##
-dnl ## configure.ac:
-dnl ## AC_CHECK_MCSC(<success-action>, <failure-action>)
-dnl ##
-
-AC_DEFUN([AC_CHECK_MCSC], [
-AC_MSG_CHECKING(for usable SVR4/SUSv2 makecontext(2)/swapcontext(2))
-AC_CACHE_VAL(ac_cv_check_mcsc, [
-AC_TRY_RUN([
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <ucontext.h>
-
-ucontext_t uc_child;
-ucontext_t uc_main;
-
-void child(void *arg)
-{
- if (arg != (void *)12345)
- exit(1);
- if (swapcontext(&uc_child, &uc_main) != 0)
- exit(1);
-}
-
-int main(int argc, char *argv[])
-{
- FILE *fp;
- void *stack;
-
- /* the default is that it fails */
- if ((fp = fopen("conftestval", "w")) == NULL)
- exit(1);
- fprintf(fp, "no\n");
- fclose(fp);
-
- /* configure a child user-space context */
- if ((stack = malloc(64*1024)) == NULL)
- exit(1);
- if (getcontext(&uc_child) != 0)
- exit(1);
- uc_child.uc_link = NULL;
- uc_child.uc_stack.ss_sp = (char *)stack+(32*1024);
- uc_child.uc_stack.ss_size = 32*1024;
- uc_child.uc_stack.ss_flags = 0;
- makecontext(&uc_child, child, 2, (void *)12345);
-
- /* switch into the user context */
- if (swapcontext(&uc_main, &uc_child) != 0)
- exit(1);
-
- /* Fine, child came home */
- if ((fp = fopen("conftestval", "w")) == NULL)
- exit(1);
- fprintf(fp, "yes\n");
- fclose(fp);
-
- /* die successfully */
- exit(0);
-}
-],
-ac_cv_check_mcsc=`cat conftestval`,
-ac_cv_check_mcsc=no,
-ac_cv_check_mcsc=no
-)dnl
-])dnl
-AC_MSG_RESULT([$ac_cv_check_mcsc])
-if test ".$ac_cv_check_mcsc" = .yes; then
- ifelse([$1], , :, [$1])
-else
- ifelse([$2], , :, [$2])
-fi
-])dnl
-
-dnl ##
-dnl ## Check how stacks have to be setup for the functions
-dnl ## sigstack(2), sigaltstack(2) and makecontext(2).
-dnl ##
-dnl ## configure.ac:
-dnl ## AC_CHECK_STACKSETUP(sigstack|sigaltstack|makecontext, <macro-addr>, <macro-size>)
-dnl ## acconfig.h:
-dnl ## #undef HAVE_{SIGSTACK|SIGALTSTACK|MAKECONTEXT}
-dnl ## #undef HAVE_STACK_T
-dnl ## header.h.in:
-dnl ## @<macro-addr>@
-dnl ## @<macro-size>@
-dnl ## source.c:
-dnl ## #include "header.h"
-dnl ## xxx.sp_ss = <macro-addr>(skaddr, sksize);
-dnl ## xxx.sp_size = <macro-size>(skaddr, sksize);
-dnl ##
-
-AC_DEFUN([AC_CHECK_STACKSETUP],[dnl
-dnl # check for consistent usage
-ifelse($1,[sigstack],,[
-ifelse($1,[sigaltstack],,[
-ifelse($1,[makecontext],,[
-errprint(__file__:__line__: [AC_CHECK_STACKSETUP: only sigstack, sigaltstack and makecontext supported
-])])])])
-dnl # we require the C compiler and the standard headers
-AC_REQUIRE([AC_HEADER_STDC])dnl
-dnl # we at least require the function to check
-AC_CHECK_FUNCS($1)
-dnl # sigaltstack on some platforms uses stack_t instead of struct sigaltstack
-ifelse($1, sigaltstack, [
- AC_ONCE(stacksetup_stack_t, [
- AC_CHECK_TYPEDEF(stack_t, signal.h)
- ])
-])
-dnl # display processing header
-AC_MSG_CHECKING(for stack setup via $1)
-dnl # but cache the whole results
-AC_CACHE_VAL(ac_cv_stacksetup_$1,[
-if test ".$ac_cv_func_$1" = .no; then
- dnl # no need to check anything when function is already missing
- ac_cv_stacksetup_$1="N.A.:/*N.A.*/,/*N.A.*/"
-else
- dnl # setup compile environment
- OCFLAGS="$CFLAGS"
- CFLAGS="$CFLAGS -DTEST_$1"
- cross_compiling=no
- dnl # compile and run the test program
- AC_TRY_RUN([
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#if defined(TEST_sigstack) || defined(TEST_sigaltstack)
-#include <sys/types.h>
-#include <signal.h>
-#include <unistd.h>
-#endif
-#if defined(TEST_makecontext)
-#include <ucontext.h>
-#endif
-union alltypes {
- long l;
- double d;
- void *vp;
- void (*fp)(void);
- char *cp;
-};
-static volatile char *handler_addr = (char *)0xDEAD;
-#if defined(TEST_sigstack) || defined(TEST_sigaltstack)
-static volatile int handler_done = 0;
-void handler(int sig)
-{
- char garbage[1024];
- int i;
- auto int dummy;
- for (i = 0; i < 1024; i++)
- garbage[i] = 'X';
- handler_addr = (char *)&dummy;
- handler_done = 1;
- return;
-}
-#endif
-#if defined(TEST_makecontext)
-static ucontext_t uc_handler;
-static ucontext_t uc_main;
-void handler(void)
-{
- char garbage[1024];
- int i;
- auto int dummy;
- for (i = 0; i < 1024; i++)
- garbage[i] = 'X';
- handler_addr = (char *)&dummy;
- swapcontext(&uc_handler, &uc_main);
- return;
-}
-#endif
-int main(int argc, char *argv[])
-{
- FILE *f;
- char *skaddr;
- char *skbuf;
- int sksize;
- char result[1024];
- int i;
- sksize = 32768;
- skbuf = (char *)malloc(sksize*2+2*sizeof(union alltypes));
- if (skbuf == NULL)
- exit(1);
- for (i = 0; i < sksize*2+2*sizeof(union alltypes); i++)
- skbuf[i] = 'A';
- skaddr = skbuf+sizeof(union alltypes);
-#if defined(TEST_sigstack) || defined(TEST_sigaltstack)
- {
- struct sigaction sa;
-#if defined(TEST_sigstack)
- struct sigstack ss;
-#elif defined(TEST_sigaltstack) && defined(HAVE_STACK_T)
- stack_t ss;
-#else
- struct sigaltstack ss;
-#endif
-#if defined(TEST_sigstack)
- ss.ss_sp = (void *)(skaddr + sksize);
- ss.ss_onstack = 0;
- if (sigstack(&ss, NULL) < 0)
- exit(1);
-#elif defined(TEST_sigaltstack)
- ss.ss_sp = (void *)(skaddr + sksize);
- ss.ss_size = sksize;
- ss.ss_flags = 0;
- if (sigaltstack(&ss, NULL) < 0)
- exit(1);
-#endif
- memset((void *)&sa, 0, sizeof(struct sigaction));
- sa.sa_handler = handler;
- sa.sa_flags = SA_ONSTACK;
- sigemptyset(&sa.sa_mask);
- sigaction(SIGUSR1, &sa, NULL);
- kill(getpid(), SIGUSR1);
- while (!handler_done)
- /*nop*/;
- }
-#endif
-#if defined(TEST_makecontext)
- {
- if (getcontext(&uc_handler) != 0)
- exit(1);
- uc_handler.uc_link = NULL;
- uc_handler.uc_stack.ss_sp = (void *)(skaddr + sksize);
- uc_handler.uc_stack.ss_size = sksize;
- uc_handler.uc_stack.ss_flags = 0;
- makecontext(&uc_handler, handler, 1);
- swapcontext(&uc_main, &uc_handler);
- }
-#endif
- if (handler_addr == (char *)0xDEAD)
- exit(1);
- if (handler_addr < skaddr+sksize) {
- /* stack was placed into lower area */
- if (*(skaddr+sksize) != 'A')
- sprintf(result, "(skaddr)+(sksize)-%d,(sksize)-%d",
- sizeof(union alltypes), sizeof(union alltypes));
- else
- strcpy(result, "(skaddr)+(sksize),(sksize)");
- }
- else {
- /* stack was placed into higher area */
- if (*(skaddr+sksize*2) != 'A')
- sprintf(result, "(skaddr),(sksize)-%d", sizeof(union alltypes));
- else
- strcpy(result, "(skaddr),(sksize)");
- }
- if ((f = fopen("conftestval", "w")) == NULL)
- exit(1);
- fprintf(f, "%s\n", result);
- fclose(f);
- exit(0);
-}
-],[
-dnl # test successully passed
-ac_cv_stacksetup_$1=`cat conftestval`
-ac_cv_stacksetup_$1="ok:$ac_cv_stacksetup_$1"
-],[
-dnl # test failed
-ac_cv_stacksetup_$1='guessed:(skaddr),(sksize)'
-],[
-dnl # cross-platform => failed
-ac_cv_stacksetup_$1='guessed:(skaddr),(sksize)'
-])
-dnl # restore original compile environment
-CFLAGS="$OCFLAGS"
-])dnl
-fi
-dnl # extract result ingredients of single cached result value
-type=`echo $ac_cv_stacksetup_$1 | sed -e 's;:.*$;;'`
-addr=`echo $ac_cv_stacksetup_$1 | sed -e 's;^.*:;;' -e 's;,.*$;;'`
-size=`echo $ac_cv_stacksetup_$1 | sed -e 's;^.*:;;' -e 's;^.*,;;'`
-dnl # export result ingredients
-$2="#define $2(skaddr,sksize) ($addr)"
-$3="#define $3(skaddr,sksize) ($size)"
-AC_SUBST($2)dnl
-AC_SUBST($3)dnl
-dnl # display result indicator
-AC_MSG_RESULT([$type])
-dnl # display results in detail
-AC_MSG_VERBOSE([$]$2)
-AC_MSG_VERBOSE([$]$3)
-])
