[Bug debug/59323] [4.9 Regression] Int. comp. error: in add_AT_specification, at dwarf2out.c:4026

rguenth at gcc dot gnu.org gcc-bugzilla@gcc.gnu.org
Thu Nov 28 10:00:00 GMT 2013


Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2013-11-28
   Target Milestone|---                         |4.9.0
     Ever confirmed|0                           |1

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.  Nested functions.  There seems to be a declaration coming in

#5  0x000000000074b91a in decls_for_scope (stmt=<block 0x7ffff6e4f190>, 
    context_die=0x7ffff6e4f050, depth=2)
    at /space/rguenther/src/svn/trunk/gcc/dwarf2out.c:19971

but the decl itself has non-BLOCK scope (its DECL_CONTEXT is the main fn).

There are two BLOCKs which contain the exact same BLOCK_VARs ...

So it seems we duplicate BLOCKs either bogously during streaming (maybe only
in the context of nested functions) or they are duplicate also in the
compile phase.

It seems that one BLOCK is BLOCK_SUPERCONTEXT of the other which cannot
really be a streaming artifact.

It's a tree merging artifact - we merge the TYPE_DECLs for

    enum { X };

which end up being written to the global section despite their
DECL_CONTEXT being a FUNCTION_DECL (bah).  Such merging happens
without considering DECL_CHAIN as we assume they are not in BLOCK
context.  They end up there because the nested function decl 'foo'
is in that same block (I think) and thus they form a tree SCC

Ah no - it's ultimately the CONST_DECL for X that pulls the enum
type and its type decl global.  Ick...

I have a fix.

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