Hi,

6 target libraries in the tree detect whether they are being compiled by a 
compiler configured for setjmp/longjmp exceptions: libada, libgcc, libgo, 
libjava, libobjc and libstdc++.  They can be divided into 3 categories:
 1) libada only checks the preprocessor macro __USING_SJLJ_EXCEPTIONS__,
 2) libgcc and libgo both check the preprocessor macro and implement a 
configure check that defines another macro (LIBGCC_SJLJ_EXCEPTIONS and 
LIBGO_SJLJ_EXCEPTIONS resp) so they'd better agree.
 3) libjava, libobjc and libstdc++ implement a configure check that defines a 
macro (SJLJ_EXCEPTIONS, SJLJ_EXCEPTIONS and _GLIBCXX_SJLJ_EXCEPTIONS resp).

The attached patch gets rid of the library-specific macros and replaces them 
with __USING_SJLJ_EXCEPTIONS__.  Moreover, it adds a config/sjlj.m4 fragment 
that defines GCC_CHECK_SJLJ_EXCEPTIONS for libraries that need to detect the 
exception model in the configure phase (libgcc and libjava only).

Tested on x86_64-suse-linux with --enable-sjlj-exceptions.  The results are 
not clean (except for objc and obj-c++) but sufficient to see that exceptions 
still work after the patch.  OK for the mainline?


2015-05-12  Eric Botcazou  <ebotcazou@adacore.com>

config/
	* sjlj.m4: New file.

libgcc/
	* configure.ac: Include config/sjlj.m4.
	Remove manual SJLJ check, add GCC_CHECK_SJLJ_EXCEPTIONS and adjust.
	* config.in: Regenerate.
	* configure: Likewise.
	* config.host: Replace enable_sjlj_exceptions by ac_cv_sjlj_exceptions.

libgo/
	* configure.ac: Remove manual SJLJ check.
	* config.h.in: Regenerate.
	* configure: Likewise.
	* runtime/go-unwind.c: Replace LIBGO_SJLJ_EXCEPTIONS by
	__USING_SJLJ_EXCEPTIONS__.

libjava/
	* configure.ac: Include config/sjlj.m4.
	Remove manual SJLJ check, add GCC_CHECK_SJLJ_EXCEPTIONS and adjust.
	* include/config.h.in: Regenerate.
	* configure: Likewise.
	* exception.cc: Replace SJLJ_EXCEPTIONS by __USING_SJLJ_EXCEPTIONS__.
	* stacktrace.cc: Likewise.
	* include/default-signal.h: Likewise.
	* sysdep/i386/backtrace.h: Likewise.

libobjc/
	* configure.ac: Remove manual SJLJ check.
	* config.h.in: Regenerate.
	* configure: Likewise.
	* exception.c: Replace SJLJ_EXCEPTIONS by __USING_SJLJ_EXCEPTIONS__.

libstdc++-v3/
	* acinclude.m4 (GLIBCXX_ENABLE_SJLJ_EXCEPTIONS): Delete.
	* configure.ac: Remove GLIBCXX_ENABLE_SJLJ_EXCEPTIONS.
	* config.h.in: Regenerate.
	* configure: Likewise.
	* libsupc++/eh_personality.cc: Replace _GLIBCXX_SJLJ_EXCEPTIONS by
	__USING_SJLJ_EXCEPTIONS__.
	* libsupc++/eh_throw.cc: Likewise.
	* libsupc++/eh_ptr.cc: Likewise.
	* doc/html/manual/appendix_porting.html: Remove
	GLIBCXX_ENABLE_SJLJ_EXCEPTIONS
	* doc/xml/manual/build_hacking.xml: Likewise.
	* doc/html/manual/configure.html: Remove --enable-sjlj-exceptions.
	* doc/xml/manual/configure.xml: Likewise.


-- 
Eric Botcazou