We'll need this for the upcoming patch to speed up expression evaluation.
Might as well push it now to see if it behaves sanely in the buildfarm.
Andres Freund
Discussion: https://postgr.es/m/
20170320062511.hp5qeurtxrwsvfxr@alap3.anarazel.de
index 7d901e1f1aa20e15e24da00d6db5b8ebaa4c88a1..3321f226f3e4abd68d679e9a03b0b4fc18fe88e9 100644 (file)
+# PGAC_C_COMPUTED_GOTO
+# -----------------------
+# Check if the C compiler knows computed gotos (gcc extension, also
+# available in at least clang). If so, define HAVE_COMPUTED_GOTO.
+#
+# Checking whether computed gotos are supported syntax-wise ought to
+# be enough, as the syntax is otherwise illegal.
+AC_DEFUN([PGAC_C_COMPUTED_GOTO],
+[AC_CACHE_CHECK(for computed goto support, pgac_cv_computed_goto,
+[AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],
+[[void *labeladdrs[] = {&&my_label};
+ goto *labeladdrs[0];
+ my_label:
+ return 1;
+]])],
+[pgac_cv_computed_goto=yes],
+[pgac_cv_computed_goto=no])])
+if test x"$pgac_cv_computed_goto" = xyes ; then
+AC_DEFINE(HAVE_COMPUTED_GOTO, 1,
+ [Define to 1 if your compiler handles computed gotos.])
+fi])# PGAC_C_COMPUTED_GOTO
+
+
+
# PGAC_C_VA_ARGS
# --------------
# Check if the C compiler understands C99-style variadic macros,
index b5cdebb510b24dff22cc168a298cdf0a5db4f257..9528622421ed863e897e51f68ba9c212adc8cb41 100755 (executable)
$as_echo "#define HAVE__BUILTIN_UNREACHABLE 1" >>confdefs.h
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for computed goto support" >&5
+$as_echo_n "checking for computed goto support... " >&6; }
+if ${pgac_cv_computed_goto+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+
+int
+main ()
+{
+void *labeladdrs[] = {&&my_label};
+ goto *labeladdrs[0];
+ my_label:
+ return 1;
+
+ ;
+ return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+ pgac_cv_computed_goto=yes
+else
+ pgac_cv_computed_goto=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_computed_goto" >&5
+$as_echo "$pgac_cv_computed_goto" >&6; }
+if test x"$pgac_cv_computed_goto" = xyes ; then
+
+$as_echo "#define HAVE_COMPUTED_GOTO 1" >>confdefs.h
+
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for __VA_ARGS__" >&5
$as_echo_n "checking for __VA_ARGS__... " >&6; }
index 1d99cda1d8e502506ee934a922169c0f5817cbc5..7f234f543dae53ab975297e88cef077b8f99907f 100644 (file)
PGAC_C_BUILTIN_BSWAP64
PGAC_C_BUILTIN_CONSTANT_P
PGAC_C_BUILTIN_UNREACHABLE
+PGAC_C_COMPUTED_GOTO
PGAC_C_VA_ARGS
PGAC_STRUCT_TIMEZONE
PGAC_UNION_SEMUN
index 5bcd8a1160fe580d10207ad3e6e93424b0e31fed..6a8176b323e38150a9598a453cd3a4179fef3420 100644 (file)
/* Define to 1 if you have the `clock_gettime' function. */
#undef HAVE_CLOCK_GETTIME
+/* Define to 1 if your compiler handles computed gotos. */
+#undef HAVE_COMPUTED_GOTO
+
/* Define to 1 if you have the <crtdefs.h> header file. */
#undef HAVE_CRTDEFS_H
index 3e4132cd82406c3fbcfb7a7c52b00aa6795e9df6..5af8369202ca8e923e05ccd7d93abf7df7acd01d 100644 (file)
/* Define to 1 if you have the `clock_gettime' function. */
/* #undef HAVE_CLOCK_GETTIME */
+/* Define to 1 if your compiler handles computed gotos. */
+/* #undef HAVE_COMPUTED_GOTO */
+
/* Define to 1 if you have the `crypt' function. */
/* #undef HAVE_CRYPT */