Works with -O2, fails with -O0, -O1, -O2 -fno-inline

-O0:
$ /scratch/obj.i686/gcc-4.3/./gcc/xgcc -B/scratch/obj.i686/gcc-4.3/./gcc/ -B/opt/i686/gcc-4.3//i686-linux-gnu/bin/ -B/opt/i686/gcc-4.3//i686-linux-gnu/lib/ -isystem /opt/i686/gcc-4.3//i686-linux-gnu/include -isystem /opt/i686/gcc-4.3//i686-linux-gnu/sys-include   -DIN_GCC    -W -Wall -Wwrite-strings -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition  -isystem ./include  -fPIC -g -DHAVE_GTHR_DEFAULT -DIN_LIBGCC2 -D__GCC_FLOAT_NOT_NEEDED   -I. -I. -I../.././gcc -I../../../../src/gcc-4.3/libgcc -I../../../../src/gcc-4.3/libgcc/. -I../../../../src/gcc-4.3/libgcc/../gcc -I../../../../src/gcc-4.3/libgcc/../include -I../../../../src/gcc-4.3/libgcc/config/libbid -DENABLE_DECIMAL_BID_FORMAT -DHAVE_CC_TLS -DUSE_TLS -o lib2addeh_static_onestep.o -MT lib2addeh_static_onestep.o -MD -MP -MF lib2addeh_static_onestep.dep -fexceptions -combine ../../../../src/gcc-4.3/libgcc/../gcc/emutls.c ../../../../src/gcc-4.3/libgcc/../gcc/gthr-gnat.c ../../../../src/gcc-4.3/libgcc/../gcc/unwind-c.c ../../../../src/gcc-4.3/libgcc/../gcc/unwind-dw2-fde-glibc.c ../../../../src/gcc-4.3/libgcc/../gcc/unwind-dw2.c ../../../../src/gcc-4.3/libgcc/../gcc/unwind-sjlj.c -fvisibility=hidden -DHIDE_EXPORTS -c -O0
/tmp/ccidDTzT.s: Assembler messages:
/tmp/ccidDTzT.s:5738: Error: symbol `size_of_encoded_value' is already defined
/tmp/ccidDTzT.s:5889: Error: symbol `read_uleb128' is already defined
/tmp/ccidDTzT.s:5932: Error: symbol `read_sleb128' is already defined
/tmp/ccidDTzT.s:5989: Error: symbol `read_encoded_value_with_base' is already defined
/tmp/ccidDTzT.s:6224: Error: symbol `get_cie' is already defined
/tmp/ccidDTzT.s:6248: Error: symbol `next_fde' is already defined


-O1:
$ /scratch/obj.i686/gcc-4.3/./gcc/xgcc -B/scratch/obj.i686/gcc-4.3/./gcc/ -B/opt/i686/gcc-4.3//i686-linux-gnu/bin/ -B/opt/i686/gcc-4.3//i686-linux-gnu/lib/ -isystem /opt/i686/gcc-4.3//i686-linux-gnu/include -isystem /opt/i686/gcc-4.3//i686-linux-gnu/sys-include   -DIN_GCC    -W -Wall -Wwrite-strings -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition  -isystem ./include  -fPIC -g -DHAVE_GTHR_DEFAULT -DIN_LIBGCC2 -D__GCC_FLOAT_NOT_NEEDED   -I. -I. -I../.././gcc -I../../../../src/gcc-4.3/libgcc -I../../../../src/gcc-4.3/libgcc/. -I../../../../src/gcc-4.3/libgcc/../gcc -I../../../../src/gcc-4.3/libgcc/../include -I../../../../src/gcc-4.3/libgcc/config/libbid -DENABLE_DECIMAL_BID_FORMAT -DHAVE_CC_TLS -DUSE_TLS -o lib2addeh_static_onestep.o -MT lib2addeh_static_onestep.o -MD -MP -MF lib2addeh_static_onestep.dep -fexceptions -combine ../../../../src/gcc-4.3/libgcc/../gcc/emutls.c ../../../../src/gcc-4.3/libgcc/../gcc/gthr-gnat.c ../../../../src/gcc-4.3/libgcc/../gcc/unwind-c.c ../../../../src/gcc-4.3/libgcc/../gcc/unwind-dw2-fde-glibc.c ../../../../src/gcc-4.3/libgcc/../gcc/unwind-dw2.c ../../../../src/gcc-4.3/libgcc/../gcc/unwind-sjlj.c -fvisibility=hidden -DHIDE_EXPORTS -c -O1
/tmp/ccNNdoTR.s: Assembler messages:
/tmp/ccNNdoTR.s:5207: Error: symbol `read_uleb128' is already defined
/tmp/ccNNdoTR.s:5260: Error: symbol `read_sleb128' is already defined
/tmp/ccNNdoTR.s:5329: Error: symbol `read_encoded_value_with_base' is already defined

I suppose the static function

static const unsigned char *
read_uleb128 (const unsigned char *p, _uleb128_t *val)
{

in unwind-pe.h should be marked 'inline', otherwise it will be emitted
multiple times to the asm file by -combine.

The static size_of_encoded_value's are supposed to be mangled when --combine,
like size_of_encoded_value.12521 and on a simple testcase with --combine
on x86_64-linux/trunk they are.

Smaller testcase:
-----------------------------------
$ cat pr35034-1.c
/* PR 35034 - fails to mangle function names for different TUs.  */
/* { dg-do compile } */
/* { dg-options "-combine -O0" } */
/* { dg-additional-sources pr35034-2.c } */
typedef int int_t;

static void
size_of_encoded_value (void)
{
};
extern int pthread_once (int_t *__once_control,
    void (*__init_routine) (void));
static __typeof(pthread_once) __gthrw_pthread_once __attribute__ ((__weakref__("pthread_once")));

-----------------------------------
$ cat pr35034-2.c 
void size_of_encoded_value (void)
{
};
-----------------------------------


Gives with current trunk:
$ gcc-4.3-HEAD pr35034-1.c pr35034-2.c -O0 -c -o foo.o -combine -pipe
{standard input}: Assembler messages:
{standard input}:12: Error: symbol `size_of_encoded_value' is already defined
$ gcc-4.3-HEAD pr35034-1.c pr35034-2.c -O0 -S -o - -combine -pipe
        .file   "pr35034-1.c"
        .text
        .type   size_of_encoded_value, @function
size_of_encoded_value:
        pushl   %ebp
        movl    %esp, %ebp
        popl    %ebp
        ret
        .size   size_of_encoded_value, .-size_of_encoded_value
.globl size_of_encoded_value
        .type   size_of_encoded_value, @function
size_of_encoded_value:
        pushl   %ebp
        movl    %esp, %ebp
        popl    %ebp
        ret
        .size   size_of_encoded_value, .-size_of_encoded_value
        .weakref        __gthrw_pthread_once,pthread_once
        .ident  "GCC: (GNU) 4.3.0 20080131 (experimental)"
        .section        .note.GNU-stack,"",@progbits

Works with gcc-4.1.2 (if one prunes the 'static' of the weakref; They were required to be public back then):

$ gcc-4.1 pr35034-1.c pr35034-2.c -O0 -S -o - -combine -pipe
        .file   "pr35034-1.c"
        .text
.globl size_of_encoded_value
        .type   size_of_encoded_value, @function
size_of_encoded_value:
        pushl   %ebp
        movl    %esp, %ebp
        popl    %ebp
        ret
        .size   size_of_encoded_value, .-size_of_encoded_value
        .weakref        __gthrw_pthread_once,pthread_once
        .ident  "GCC: (GNU) 4.1.2 20061115 (prerelease) (Debian 4.1.1-21)"
        .section        .note.GNU-stack,"",@progbits

Confirmed.  The following also fails with optimization:

t1.c:
static void __attribute__((used))
size_of_encoded_value (void)
{
};
static int __gthrw_pthread_once __attribute__ ((__weakref__("pthread_once")));

t2.c:
void size_of_encoded_value (void)
{
};


Not a regression.

Fails with 4.1.2 for me as well, with the static.  w/o 4.1 complains

t1.c:5: error: '__gthrw_pthread_once' defined both normally and as an alias

(In reply to comment #2)
> I suppose the static function
> 
> static const unsigned char *
> read_uleb128 (const unsigned char *p, _uleb128_t *val)
> {
> 
> in unwind-pe.h should be marked 'inline', otherwise it will be emitted
> multiple times to the asm file by -combine.

unwind-pe.h as a header should provide an interface to and not implementations of the required functions. Apart from fixing the functions in IMA, unwind-pe.h should split it's implementations off into a e.g. unwind-pe.c that exports the common helpers.

Does somebody know if it is really intended that dwarf2asm.c has grown (or kept) a different impl of size_of_encoded_value() than all the rest?

(In reply to comment #7)
> Fails with 4.1.2 for me as well, with the static.  w/o 4.1 complains
> 
> t1.c:5: error: '__gthrw_pthread_once' defined both normally and as an alias
> 

Works flawlessly for me (without the static, on debian with the debian-patched cc):
$ gcc-4.1 pr35034-1.c pr35034-2.c -O0 -c -o foo.o -combine -pipe ; echo $?
0

That's a accepts-invalid problem on 4.1, try the same thing with the reduced
testcase from comment #6.

*** Bug 38460 has been marked as a duplicate of this bug. ***

-combine has been removed from GCC 4.6 in favor of LTO, closing as WONTFIX.