Factor out compiler test program into a macro.

ok djm@

diff --git a/m4/openssh.m4 b/m4/openssh.m4
index e6d392a02ded19a2008844e20a2e965c559c1728..386a616f2371d5a1b3ebb2c0349a762ea4b138c6 100644 (file)
--- a/m4/openssh.m4
+++ b/m4/openssh.m4
@@ -1,30 +1,26 @@
 dnl OpenSSH-specific autoconf macros
 dnl
 
-dnl OSSH_CHECK_CFLAG_COMPILE(check_flag[, define_flag])
-dnl Check that $CC accepts a flag 'check_flag'. If it is supported append
-dnl 'define_flag' to $CFLAGS. If 'define_flag' is not specified, then append
-dnl 'check_flag'.
-AC_DEFUN([OSSH_CHECK_CFLAG_COMPILE], [{
-       AC_MSG_CHECKING([if $CC supports compile flag $1])
-       saved_CFLAGS="$CFLAGS"
-       CFLAGS="$CFLAGS $WERROR $1"
-       _define_flag="$2"
-       test "x$_define_flag" = "x" && _define_flag="$1"
-       AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
+dnl The test program that is used to try to trigger various compiler
+dnl behaviours.
+AC_DEFUN([OSSH_COMPILER_FLAG_TEST_PROGRAM],
+       [AC_LANG_SOURCE([[
 #include <stdlib.h>
 #include <stdio.h>
+#include <unistd.h>
 /* Trivial function to help test for -fzero-call-used-regs */
 int f(int n) {return rand() % n;}
 int main(int argc, char **argv) {
        (void)argv;
+       char b[256];
        /* Some math to catch -ftrapv problems in the toolchain */
        int i = 123 * argc, j = 456 + argc, k = 789 - argc;
        float l = i * 2.1;
        double m = l / 0.5;
        long long int n = argc * 12345LL, o = 12345LL * (long long int)argc;
        f(0);
-       printf("%d %d %d %f %f %lld %lld\n", i, j, k, l, m, n, o);
+       snprintf(b, sizeof b, "%d %d %d %f %f %lld %lld\n", i,j,k,l,m,n,o);
+       write(1, b, 0);
        /*
         * Test fallthrough behaviour.  clang 10's -Wimplicit-fallthrough does
         * not understand comments and we don't use the "fallthrough" attribute
@@ -37,7 +33,20 @@ int main(int argc, char **argv) {
        }
        exit(0);
 }
-       ]])],
+       ]])]
+)
+
+dnl OSSH_CHECK_CFLAG_COMPILE(check_flag[, define_flag])
+dnl Check that $CC accepts a flag 'check_flag'. If it is supported append
+dnl 'define_flag' to $CFLAGS. If 'define_flag' is not specified, then append
+dnl 'check_flag'.
+AC_DEFUN([OSSH_CHECK_CFLAG_COMPILE], [{
+       AC_MSG_CHECKING([if $CC supports compile flag $1])
+       saved_CFLAGS="$CFLAGS"
+       CFLAGS="$CFLAGS $WERROR $1"
+       _define_flag="$2"
+       test "x$_define_flag" = "x" && _define_flag="$1"
+       AC_COMPILE_IFELSE([OSSH_COMPILER_FLAG_TEST_PROGRAM],
                [
 if $ac_cv_path_EGREP -i "unrecognized option|warning.*ignored" conftest.err >/dev/null
 then
@@ -62,24 +71,7 @@ AC_DEFUN([OSSH_CHECK_CFLAG_LINK], [{
        CFLAGS="$CFLAGS $WERROR $1"
        _define_flag="$2"
        test "x$_define_flag" = "x" && _define_flag="$1"
-       AC_LINK_IFELSE([AC_LANG_SOURCE([[
-#include <stdlib.h>
-#include <stdio.h>
-/* Trivial function to help test for -fzero-call-used-regs */
-int f(int n) {return rand() % n;}
-int main(int argc, char **argv) {
-       (void)argv;
-       /* Some math to catch -ftrapv problems in the toolchain */
-       int i = 123 * argc, j = 456 + argc, k = 789 - argc;
-       float l = i * 2.1;
-       double m = l / 0.5;
-       long long int n = argc * 12345LL, o = 12345LL * (long long int)argc;
-       long long int p = n * o;
-       f(0);
-       printf("%d %d %d %f %f %lld %lld %lld\n", i, j, k, l, m, n, o, p);
-       exit(0);
-}
-       ]])],
+       AC_LINK_IFELSE([OSSH_COMPILER_FLAG_TEST_PROGRAM],
                [
 if $ac_cv_path_EGREP -i "unrecognized option|warning.*ignored" conftest.err >/dev/null
 then
@@ -104,24 +96,7 @@ AC_DEFUN([OSSH_CHECK_LDFLAG_LINK], [{
        LDFLAGS="$LDFLAGS $WERROR $1"
        _define_flag="$2"
        test "x$_define_flag" = "x" && _define_flag="$1"
-       AC_LINK_IFELSE([AC_LANG_SOURCE([[
-#include <stdlib.h>
-#include <stdio.h>
-/* Trivial function to help test for -fzero-call-used-regs */
-int f(int n) {return rand() % n;}
-int main(int argc, char **argv) {
-       (void)argv;
-       /* Some math to catch -ftrapv problems in the toolchain */
-       int i = 123 * argc, j = 456 + argc, k = 789 - argc;
-       float l = i * 2.1;
-       double m = l / 0.5;
-       long long int n = argc * 12345LL, o = 12345LL * (long long int)argc;
-       long long p = n * o;
-       f(0);
-       printf("%d %d %d %f %f %lld %lld %lld\n", i, j, k, l, m, n, o, p);
-       exit(0);
-}
-               ]])],
+       AC_LINK_IFELSE([OSSH_COMPILER_FLAG_TEST_PROGRAM],
                [
 if $ac_cv_path_EGREP -i "unrecognized option|warning.*ignored" conftest.err >/dev/null
 then