[Bug debug/11500] New: [3.4 regression] gcc HEAD emits an extraneous "line 0" debug line at the start of each function

["mec at shout dot net" <gcc-bugzilla at gcc dot gnu dot org>]

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11500

           Summary: [3.4 regression] gcc HEAD emits an extraneous "line 0"
                    debug line at the start of each function
           Product: gcc
           Version: 3.4
            Status: UNCONFIRMED
          Severity: critical
          Priority: P2
         Component: debug
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: mec at shout dot net
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu

gcc HEAD emits an extraneous "line 0" debug line at the start of each function.
 This definitely happens with -gstabs+ and I believe it happens with gcc
-gdwarf-2 as well.

John Parkes originally reported this:

  http://gcc.gnu.org/ml/gcc/2003-07/msg00827.html

The problem started with this patch:

  Sun Jun  8 21:27:41 CEST 2003  Jan Hubicka  <jh@suse.cz>

    ...
    * final.c (notice_source_line): Use locators.
    (final_start_function): Set initial source file and line.
    (final_scan_insn): Use locators.
    ...

Before this patch, final_start_function called begin_prologue with the line
number and filename of the function.  Now final_start_function calls
begin_prologue with line=0 and filename=0.

See the attachment for more details.