[Bug debug/54826] New: gdb test case failure (bs15503) due to gaps in lexical block

[Bug debug/54826] New: gdb test case failure (bs15503) due to gaps in lexical block

[arnez at linux dot vnet.ibm.com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54826

             Bug #: 54826
           Summary: gdb test case failure (bs15503) due to gaps in lexical
                    block
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: debug
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: arnez@linux.vnet.ibm.com


Current upstream gcc causes a regression with the gdb test case
bs15503.exp:
FAIL: gdb.cp/bs15503.exp: print s.length()
FAIL: gdb.cp/bs15503.exp: print s[0]
FAIL: gdb.cp/bs15503.exp: print s[s.length()-1]
FAIL: gdb.cp/bs15503.exp: print (const char *) s
FAIL: gdb.cp/bs15503.exp: print (const char *) s.substr(0,4)
FAIL: gdb.cp/bs15503.exp: print (const char *) (s=s.substr(0,4))

What happens is that the DWARF output for bs15503.cc wraps the string
variable "s" from StringTest<wchar_t>::testFunction() in a lexical
block with spurious gaps.  The test case happens to set a break point
into one of these gaps and tries to access the variable from there,
which gdb (correctly) refuses.

For reference, here's a link to the source code:
http://sourceware.org/cgi-bin/cvsweb.cgi/~checkout~/src/gdb/testsuite/gdb.cp/bs15503.cc?rev=1.11&cvsroot=src

I've verified the failure on x86_64 and s390x.  The regression was
introduced by: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=191494

[Bug debug/54826] gdb test case failure (bs15503) due to gaps in lexical block

[dehao at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54826

dehao at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2012-10-05
                 CC|                            |dehao at gcc dot gnu.org
         AssignedTo|unassigned at gcc dot       |dehao at gcc dot gnu.org
                   |gnu.org                     |
     Ever Confirmed|0                           |1

[Bug debug/54826] gdb test case failure (bs15503) due to gaps in lexical block

[dehao at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54826

--- Comment #1 from dehao at gcc dot gnu.org 2012-10-06 02:27:27 UTC ---
A patch is sent to solve this:

http://gcc.gnu.org/ml/gcc-patches/2012-10/msg00596.html

[Bug debug/54826] gdb test case failure (bs15503) due to gaps in lexical block

[dehao at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54826

--- Comment #2 from dehao at gcc dot gnu.org 2012-10-06 16:19:43 UTC ---
Author: dehao
Date: Sat Oct  6 16:19:34 2012
New Revision: 192165

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=192165
Log:
2012-10-05  Dehao Chen  <dehao@google.com>

    PR debug/54826
    * gimple-low.c (lower_stmt): Set the block for call args.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/gimple-low.c

[Bug debug/54826] gdb test case failure (bs15503) due to gaps in lexical block

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54826

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED

--- Comment #3 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-10-08 12:07:55 UTC ---
Fixed.

[Bug debug/54826] gdb test case failure (bs15503) due to gaps in lexical block

[arnez at linux dot vnet.ibm.com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54826

Andreas Arnez <arnez at linux dot vnet.ibm.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |CLOSED

--- Comment #4 from Andreas Arnez <arnez at linux dot vnet.ibm.com> 2012-10-09 09:02:08 UTC ---
Very well, thanks!