Re: [patch] PR40134, use a linker script on arm-linux to link with -lgcc_s -lgcc

[Matthias Klose <doko at ubuntu dot com>]

Jakub Jelinek schrieb:
> On Tue, Jul 07, 2009 at 11:03:24AM +0200, Matthias Klose wrote:
>> Use a linker script to link with -lgcc_s -lgcc on arm-linux, which allows the
>> arm-linux target to run the testsuite without regressions with the patch for the
>> exception propagation support [1] enabled.
>>
>> The approach taken is the same as used on the sh-linux configuration.
>>
>> Tested on the 4.4 branch without regressions (c, c++, fortran, objc, obj-c++),
>> the trunk currently fails to build for unrelated reasons [2]
>>
>> Ok for the branch (and for the trunk after it bootstraps again)?
> 
> For branch I think this could be acceptable, but for trunk I really think
> we should do this on all architectures that have shared libgcc_s*.
> It is not just arm/sh that need this, but also e.g. ppc-linux (and maybe
> ppc64-linux), where libgcc.a only contains the out of line gpr/fpr register
> save/restores.
> 
> Something like (untested):
> 
> --- gcc.c	2009-06-11 13:24:15.000000000 +0200
> +++ gcc.c	2009-07-07 11:11:27.664079777 +0200
> @@ -1733,11 +1733,11 @@ init_gcc_specs (struct obstack *obstack,
>  		"}"
>  #ifdef LINK_EH_SPEC
>  		"%{shared:"
> -		"%{shared-libgcc:", shared_name, "}"
> +		"%{shared-libgcc:", shared_name, " ", static_name, "}"
>  		"%{!shared-libgcc:", static_name, "}"
>  		"}"
>  #else
> -		"%{shared:", shared_name, "}"
> +		"%{shared:", shared_name, " ", static_name, "}"
>  #endif
>  #endif
>  		"}}", NULL);
> 
> Most of libgcc.a is sane and on targets with visibility support
> makes all symbols hidden anyway.

I've tested the attached patch without regressions on arm-linux-gnueabi,
currently running tests on ix86 and powerpc.

> The major exception here are the dfp bits, here I'd think we should remove
> them from libgcc.a and put into libgcc_dfp.a or something similar
> (and have libgcc_dfp.so too).

H.J. mentioned not to bother with the dfp library for now. Is the current patch
good enough for mainline?

  Matthias

Index: gcc.c
===================================================================
--- a/src/gcc/gcc.c	(revision 149315)
+++ b/src/gcc/gcc.c	(working copy)
@@ -1686,13 +1686,21 @@
 		"}"
 #ifdef LINK_EH_SPEC
 		"%{shared:"
+#ifdef ENABLE_SHARED_LIBGCC
+		"%{shared-libgcc:", shared_name, " ", static_name, "}"
+#else
 		"%{shared-libgcc:", shared_name, "}"
+#endif
 		"%{!shared-libgcc:", static_name, "}"
 		"}"
 #else
+#ifdef ENABLE_SHARED_LIBGCC
+		"%{shared:", shared_name, " ", static_name, "}"
+#else
 		"%{shared:", shared_name, "}"
 #endif
 #endif
+#endif
 		"}}", NULL);
 
   obstack_grow (obstack, buf, strlen (buf));