I am a bit cautious with this change, but please go ahead assuming the testing
turns out okay.
Gautam
From: Jian-Xin Lai <laij...@gmail.com>
To: Gautam Chakrabarti <gautam.c...@yahoo.com>
Cc: open64-devel <open64-devel@lists.sourceforge.net>
Sent: Friday, September 16, 2011 12:27 AM
Subject: Re: [Open64-devel] Code review for bug #827 [GCC FE]
The flag is set when the asm code of caller is emitted. Here is the stack trace:
#0 mark_referenced (id=0x55877288) at
../../../osprey-gcc-4.2.0/gcc/varasm.c:2067
#1 0x085062eb in assemble_name (file=0x8855788, name=0x8856a31 "_Z1fv") at
../../../osprey-gcc-4.2.0/gcc/varasm.c:2155
#2 0x082aa373 in output_addr_const (file=0x8855788, x=0x5586f840) at
../../../osprey-gcc-4.2.0/gcc/final.c:3213
#3 0x0855451f in print_operand (file=0x8855788, x=0x5586f840, code=80) at
../../../osprey-gcc-4.2.0/gcc/config/i386/i386.c:8167
#4 0x082aa298 in output_operand (x=0x5586f840, code=80) at
../../../osprey-gcc-4.2.0/gcc/final.c:3177
#5 0x082a9ff5 in output_asm_insn (template=0x86fb45c "call\t%P0",
operands=0x880fc60) at ../../../osprey-gcc-4.2.0/gcc/final.c:3087
#6 0x082a925b in final_scan_insn (insn=0x55741084, file=0x8855788, optimize=0,
nopeepholes=0, seen=0xffffcfcc) at ../../../osprey-gcc-4.2.0/\
gcc/final.c:2472
#7 0x082a8413 in final (first=0x557470a0, file=0x8855788, optimize=0) at
../../../osprey-gcc-4.2.0/gcc/final.c:1614
#8 0x082ab17d in rest_of_handle_final () at
../../../osprey-gcc-4.2.0/gcc/final.c:3920
#9 0x0851b8c5 in execute_one_pass (pass=0x8779200) at
../../../osprey-gcc-4.2.0/gcc/passes.c:900
#10 0x0851ba06 in execute_pass_list (pass=0x8779200) at
../../../osprey-gcc-4.2.0/gcc/passes.c:951
#11 0x0851ba22 in execute_pass_list (pass=0x8779f40) at
../../../osprey-gcc-4.2.0/gcc/passes.c:952
#12 0x0851ba22 in execute_pass_list (pass=0x8779f00) at
../../../osprey-gcc-4.2.0/gcc/passes.c:952
#13 0x0815a158 in tree_rest_of_compilation (fndecl=0x55873700) at
../../../osprey-gcc-4.2.0/gcc/tree-optimize.c:483
#14 0x080e1468 in expand_body (fn=0x55873700) at
../../../osprey-gcc-4.2.0/gcc/cp/semantics.c:3100
#15 0x0857ef86 in cgraph_expand_function (node=0x55740a20) at
../../../osprey-gcc-4.2.0/gcc/cgraphunit.c:1244
#16 0x0857f0bb in cgraph_expand_all_functions () at
../../../osprey-gcc-4.2.0/gcc/cgraphunit.c:1309
#17 0x0857f8ab in cgraph_optimize () at
../../../osprey-gcc-4.2.0/gcc/cgraphunit.c:1588
#18 0x0809b40d in cp_finish_file () at
../../../osprey-gcc-4.2.0/gcc/cp/decl2.c:3410
#19 0x08049e28 in finish_file () at
../../../osprey-gcc-4.2.0/gcc/cp/cp-lang.c:160
#20 0x08139017 in c_common_parse_file (set_yydebug=0) at
../../../osprey-gcc-4.2.0/gcc/c-opts.c:1193
#21 0x084dcfc3 in compile_file () at ../../../osprey-gcc-4.2.0/gcc/toplev.c:1077
#22 0x084de743 in do_compile () at ../../../osprey-gcc-4.2.0/gcc/toplev.c:2094
#23 0x084de7a8 in toplev_main (argc=11, argv=0xffffd334) at
../../../osprey-gcc-4.2.0/gcc/toplev.c:2126
#24 0x08143fa5 in main (argc=11, argv=0xffffd334) at
../../../osprey-gcc-4.2.0/gcc/main.c:52
mark_referenced() is only called when the compiler assemble the symbol name
during the final asm emit phase. Since we skipped all the
"tree_rest_of_compilation", the flag is not set in the modified front end.
2011/9/16 Gautam Chakrabarti <gautam.c...@yahoo.com>
What phase is it? Is it really not run, or just that it is run after tree->gs
translation? If the phase is run after the translation, then there are other
instances of this scenario, and we use gs_set_flag_value() to update the flag
of the already created gs node.
>
>The proposed change in itself is small, but I wanted to be cautious because
>
>1. that particular place is just a (mostly faithful) translation phase from
>tree -> gs, so it would be good to not have to update the tree there.
>2. And in the past the matter of setting what functions need to be
>defined/emitted has proved tricky because differences between our notion of
>needing to emit a function and g++'s notion can cause trouble.
>
>Gautam
>
>
>
>From: Jian-Xin Lai <laij...@gmail.com>
>To: Gautam Chakrabarti <gautam.c...@yahoo.com>
>Cc: open64-devel <open64-devel@lists.sourceforge.net>
>Sent: Thursday, September 15, 2011 1:15 AM
>
>Subject: Re: [Open64-devel] Code review for bug #827 [GCC FE]
>
>
>
>GCC checks this and set the flag in the later phase but we skip all those
>phase.
>
>
>2011/9/15 Gautam Chakrabarti <gautam.c...@yahoo.com>
>
>Hi Jian-Xin,
>>
>>Where does normal g++ execution set this flag? I.e., why is it not getting
>>set for us?
>>
>>Thanks,
>>Gautam
>>
>>
>>
>>From: Jian-Xin Lai <laij...@gmail.com>
>>
>>To: open64-devel <open64-devel@lists.sourceforge.net>
>>Sent: Tuesday, September 13, 2011 12:49 AM
>>Subject: Re: [Open64-devel] Code review for bug #827 [GCC FE]
>>
>>
>>
>>Hi,
>>Could a gate keeper review this patch? Thank you very much.
>>
>>
>>2011/9/7 Jian-Xin Lai <laij...@gmail.com>
>>
>>Hi,
>>>
>>>Could a gate keeper review the patch for #827? Thank you very much.
>>>
>>>The error message should be reported at toplev.c, line 884:
>>> 874 if (TREE_CODE (decl) == FUNCTION_DECL
>>> 875 && DECL_INITIAL (decl) == 0
>>> 876 && DECL_EXTERNAL (decl)
>>> 877 && ! DECL_ARTIFICIAL (decl)
>>> 878 && ! TREE_NO_WARNING (decl)
>>> 879 && ! TREE_PUBLIC (decl)
>>> 880 && (warn_unused_function
>>> 881 || TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl))))
>>> 882 {
>>> 883 if (TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl)))
>>> 884 pedwarn ("%q+F used but never defined", decl);
>>> 885 else
>>> 886 warning (0, "%q+F declared %<static%> but never defined",
>>>decl);
>>> 887 /* This symbol is effectively an "extern" declaration now. */
>>> 888 TREE_PUBLIC (decl) = 1;
>>> 889 assemble_external (decl);
>>> 890 }
>>>
>>>
>>>But because the TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl)) is not
>>>set for the callee in this case, the compiler doesn't report any error on
>>>this case. The patch is to set this flag when handle the CALL_EXPR:
>>>
>>>Index: /open64/open64-trunk/osprey-gcc-4.2.0/gcc/tree.c
>>>===================================================================
>>>--- /open64/open64-trunk/osprey-gcc-4.2.0/gcc/tree.c (revision 3731)
>>>+++ /open64/open64-trunk/osprey-gcc-4.2.0/gcc/tree.c (working copy)
>>>@@ -10916,6 +10916,16 @@
>>> /* bug 12598: Try to fold OBJ_TYPE_REF if it is present
>>> under the CALL_EXPR. Code adapted from fold_stmt() . */
>>> tree callee = get_callee_fndecl (t);
>>>+ if (callee && TREE_CODE(callee) == FUNCTION_DECL)
>>>+ {
>>>+ /* we need to emit the function be calleed, no matter
>>>+ if the call is removed later by gcc cfg cleanup, so
>>>+ the open64 backend wouldn't be surprised by missing
>>>+ function definition. */
>>>+ TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (callee)) = 1;
>>>+ mark_decl_referenced(callee);
>>>+ }
>>>+
>>> if (!(callee && DECL_BUILT_IN(callee)))
>>> {
>>> callee = TREE_OPERAND(t,0);
>>>
>>>
>>>--
>>>Regards,
>>>Lai Jian-Xin
>>>
>>
>>
>>--
>>Regards,
>>Lai Jian-Xin
>>
>>------------------------------------------------------------------------------
>>BlackBerry® DevCon Americas, Oct. 18-20, San Francisco, CA
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>>https://lists.sourceforge.net/lists/listinfo/open64-devel
>>
>>
>>
>
>
>--
>Regards,
>Lai Jian-Xin
>
>
>
--
Regards,
Lai Jian-Xin------------------------------------------------------------------------------
BlackBerry® DevCon Americas, Oct. 18-20, San Francisco, CA
http://p.sf.net/sfu/rim-devcon-copy2
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