On Fri, May 27, 2011 at 06:30:21AM -0700, Ian Lance Taylor wrote:
> Jonathan Wakely <jwakely....@gmail.com> writes:
> > It's an additional maintenance burden.
>
> It's not a maintenance burden on gcc, though.
>
> I think we should have the gcc configure script provide a way to add a
> preprocessor macro.
FWIW, we decided we needed similar capabilities in our compilers and
decided to add a --with-specs option, which enables additional
flexibility, particularly WRT optimization capabilities.
Below is the patch against our 4.5 tree, written by Nathan Sidwell.
-Nathan
* configure.ac (--with-specs): New option.
* configure: Regenerated.
* gcc.c (driver_self_specs): Include CONFIGURE_SPECS.
* Makefile.in (DRIVER_DEFINES): Add -DCONFIGURE_SPECS.
Index: gcc/gcc.c
===================================================================
--- gcc/gcc.c (revision 271022)
+++ gcc/gcc.c (revision 271023)
@@ -955,7 +955,7 @@ static const char *const multilib_defaul
static const char *const driver_self_specs[] = {
"%{fdump-final-insns:-fdump-final-insns=.} %<fdump-final-insns",
- DRIVER_SELF_SPECS, GOMP_SELF_SPECS
+ DRIVER_SELF_SPECS, CONFIGURE_SPECS, GOMP_SELF_SPECS
};
#ifndef OPTION_DEFAULT_SPECS
Index: gcc/configure.ac
===================================================================
--- gcc/configure.ac (revision 271022)
+++ gcc/configure.ac (revision 271023)
@@ -785,6 +785,14 @@ AC_SUBST(TARGET_SYSTEM_ROOT)
AC_SUBST(TARGET_SYSTEM_ROOT_DEFINE)
AC_SUBST(CROSS_SYSTEM_HEADER_DIR)
+AC_ARG_WITH(specs,
+ [AS_HELP_STRING([--with-specs=SPECS],
+ [add SPECS to driver command-line processing])],
+ [CONFIGURE_SPECS=$withval],
+ [CONFIGURE_SPECS=]
+)
+AC_SUBST(CONFIGURE_SPECS)
+
# Build with intermodule optimisations
AC_ARG_ENABLE(intermodule,
[ --enable-intermodule build the compiler in one step],
Index: gcc/Makefile.in
===================================================================
--- gcc/Makefile.in (revision 271022)
+++ gcc/Makefile.in (revision 271023)
@@ -2100,7 +2100,8 @@ DRIVER_DEFINES = \
-DTOOLDIR_BASE_PREFIX=\"$(libsubdir_to_prefix)$(prefix_to_exec_prefix)\" \
@TARGET_SYSTEM_ROOT_DEFINE@ \
$(VALGRIND_DRIVER_DEFINES) \
- `test "X$${SHLIB_LINK}" = "X" || test "@enable_shared@" != "yes" || echo
"-DENABLE_SHARED_LIBGCC"`
+ `test "X$${SHLIB_LINK}" = "X" || test "@enable_shared@" != "yes" || echo
"-DENABLE_SHARED_LIBGCC"` \
+ -DCONFIGURE_SPECS="\"@CONFIGURE_SPECS@\""
gcc.o: gcc.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) intl.h multilib.h \
Makefile $(lang_specs_files) specs.h prefix.h $(GCC_H) $(FLAGS_H) \
