X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/2b45240d6c1b9177533aa5d83ac1c879198111c5..c6b1772473d0a26faa22464df98718d0d0ae2e2e:/m4/c-working.m4

diff --git a/m4/c-working.m4 b/m4/c-working.m4
index fbc6da44..ee84acf9 100644
--- a/m4/c-working.m4
+++ b/m4/c-working.m4
@@ -25,3 +25,47 @@ AC_DEFUN([BISON_TEST_FOR_WORKING_C_COMPILER], [
     [],
     [AC_MSG_FAILURE([cannot compile a simple C program])])
 ])
+
+# BISON_CHECK_WITH_POSIXLY_CORRECT(CODE)
+# --------------------------------------
+# Run the Autoconf CODE with POSIXLY_CORRECT set to 1, and restored to
+# its initial value afterwards.
+AC_DEFUN([BISON_CHECK_WITH_POSIXLY_CORRECT],
+[gl_awk_probe='BEGIN { if ("POSIXLY_CORRECT" in ENVIRON) print "x" }'
+case ${POSIXLY_CORRECT+x}`$AWK "$gl_awk_probe" </dev/null` in
+  xx) gl_had_POSIXLY_CORRECT=exported ;;
+  x)  gl_had_POSIXLY_CORRECT=yes      ;;
+  *)  gl_had_POSIXLY_CORRECT=         ;;
+esac
+POSIXLY_CORRECT=1
+export POSIXLY_CORRECT
+$1
+case $gl_had_POSIXLY_CORRECT in
+  exported) ;;
+  yes) AS_UNSET([POSIXLY_CORRECT]); POSIXLY_CORRECT=1 ;;
+  *) AS_UNSET([POSIXLY_CORRECT]) ;;
+esac
+])
+
+# BISON_C_COMPILER_POSIXLY_CORRECT
+# --------------------------------
+# Whether the compiler supports -g in POSIXLY_CORRECT mode.  clang-2.9
+# on OS X does not, because "clang-mp-2.9 -o test -g test.c" launches
+# "/usr/bin/dsymutil test -o test.dSYM" which fails with "error:
+# unable to open executable '-o'".
+#
+# Sets C_COMPILER_POSIXLY_CORRECT to true/false.
+AC_DEFUN([BISON_C_COMPILER_POSIXLY_CORRECT],
+[AC_CACHE_CHECK([whether $CC supports POSIXLY_CORRECT=1],
+                [bison_cv_cc_supports_posixly_correct],
+[BISON_CHECK_WITH_POSIXLY_CORRECT(
+[AC_LANG_PUSH([C])
+AC_LINK_IFELSE([AC_LANG_PROGRAM],
+                [bison_cv_cc_supports_posixly_correct=yes],
+                [bison_cv_cc_supports_posixly_correct=no])
+AC_LANG_POP([C])])])
+case $bison_cv_cc_supports_posixly_correct in
+  yes) AC_SUBST([C_COMPILER_POSIXLY_CORRECT], [true]) ;;
+  no)  AC_SUBST([C_COMPILER_POSIXLY_CORRECT], [false]);;
+esac
+])