This is an update to Fredrik Hederstierna's mail and patch from
12 Apr 2012. I think he missed one place where -fexceptions needs
to be changed to -fno-exceptions.
With the attached patch, two of us (a friend and I, one on Linux and
one on Mac) can build Rockbox with gcc-4.7.0. I'll admit I haven't
checked the repository for changes in this area, this patch is based
on stock released gcc-4.7.0.
I have no opinion on Sebastian Huber's idea of making functionality
of this kind implicit with target.
- Larry
diff -ur libgcc-orig/configure libgcc-baremetal/configure
--- libgcc-orig/configure 2012-01-22 22:25:28.000000000 -0800
+++ libgcc-baremetal/configure 2012-05-31 07:30:36.000000000 -0700
@@ -600,6 +600,7 @@
set_use_emutls
set_have_cc_tls
vis_hide
+enable_libunwind_exceptions
fixed_point
enable_decimal_float
decimal_float
@@ -697,6 +698,7 @@
with_build_libsubdir
enable_decimal_float
with_system_libunwind
+enable_libunwind_exceptions
enable_sjlj_exceptions
enable_tls
'
@@ -1332,6 +1334,8 @@
enable decimal float extension to C. Selecting 'bid'
or 'dpd' choses which decimal floating point format
to use
+ --disable-libunwind-exceptions
+ disable use of libunwind when build libgcc
--enable-sjlj-exceptions
force use of builtin_setjmp for exceptions
--enable-tls Use thread-local storage [default=yes]
@@ -4493,6 +4497,15 @@
fi
+# For bare metal toolchain libundwind exceptions can be disabled
+# Check whether --enable-libunwind-exceptions was given.
+if test "${enable_libunwind_exceptions+set}" = set; then :
+ enableval=$enable_libunwind_exceptions; enable_libunwind_exceptions=$enableval
+else
+ enable_libunwind_exceptions=yes
+fi
+
+
# The sjlj test is almost duplicated here and in libgo/configure.ac (for C),
# libstdc++-v3/acinclude.m4 and libjava/configure.ac (for C++), and
# libobjc/configure.ac (for Objective-C).
diff -ur libgcc-orig/configure.ac libgcc-baremetal/configure.ac
--- libgcc-orig/configure.ac 2011-11-07 08:34:31.000000000 -0800
+++ libgcc-baremetal/configure.ac 2012-05-27 11:49:22.000000000 -0700
@@ -184,6 +184,14 @@
# config.gcc also contains tests of with_system_libunwind.
GCC_CHECK_UNWIND_GETIPINFO
+# For bare metal toolchain libundwind exceptions can be disabled
+AC_ARG_ENABLE(libunwind-exceptions,
+ [AC_HELP_STRING([--disable-libunwind-exceptions],
+ [disable use of libunwind when build libgcc])],
+ [enable_libunwind_exceptions=$enableval],
+ [enable_libunwind_exceptions=yes])
+AC_SUBST(enable_libunwind_exceptions)
+
# The sjlj test is almost duplicated here and in libgo/configure.ac (for C),
# libstdc++-v3/acinclude.m4 and libjava/configure.ac (for C++), and
# libobjc/configure.ac (for Objective-C).
diff -ur libgcc-orig/Makefile.in libgcc-baremetal/Makefile.in
--- libgcc-orig/Makefile.in 2011-11-21 19:01:02.000000000 -0800
+++ libgcc-baremetal/Makefile.in 2012-05-29 18:45:03.000000000 -0700
@@ -41,6 +41,7 @@
decimal_float = @decimal_float@
enable_decimal_float = @enable_decimal_float@
fixed_point = @fixed_point@
+enable_libunwind_exceptions = @enable_libunwind_exceptions@
host_noncanonical = @host_noncanonical@
target_noncanonical = @target_noncanonical@
@@ -497,17 +498,23 @@
endif
# Build LIB2_DIVMOD_FUNCS.
+ifeq ($(enable_libunwind_exceptions),yes)
+LIB2_DIVMOD_CFLAGS := -fexceptions -fnon-call-exceptions
+else
+LIB2_DIVMOD_CFLAGS := -fno-exceptions -fno-non-call-exceptions
+endif
+
lib2-divmod-o = $(patsubst %,%$(objext),$(LIB2_DIVMOD_FUNCS))
$(lib2-divmod-o): %$(objext): $(srcdir)/libgcc2.c
$(gcc_compile) -DL$* -c $< \
- -fexceptions -fnon-call-exceptions $(vis_hide)
+ $(LIB2_DIVMOD_CFLAGS) $(vis_hide)
libgcc-objects += $(lib2-divmod-o)
ifeq ($(enable_shared),yes)
lib2-divmod-s-o = $(patsubst %,%_s$(objext),$(LIB2_DIVMOD_FUNCS))
$(lib2-divmod-s-o): %_s$(objext): $(srcdir)/libgcc2.c
$(gcc_s_compile) -DL$* -c $< \
- -fexceptions -fnon-call-exceptions
+ $(LIB2_DIVMOD_CFLAGS) $(vis_hide)
libgcc-s-objects += $(lib2-divmod-s-o)
endif
@@ -810,7 +817,11 @@
# libgcc_eh.a, only LIB2ADDEH matters. If we do, only LIB2ADDEHSTATIC and
# LIB2ADDEHSHARED matter. (Usually all three are identical.)
+ifeq ($(enable_libunwind_exceptions),yes)
c_flags := -fexceptions
+else
+c_flags := -fno-exceptions
+endif
ifeq ($(enable_shared),yes)
