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To: bug-gdb@gnu.org
Subject: BUG REPORT


1. GDB version 6.1 and lower


2. Native platform is `i686-pc-linux-gnu',
   target platform is `mips64-*-*'


3. GDB was compiled with GCC 3.2.2


4. The debugged program was compiled with GCC 3.4


5. Options used for compilation of the debugged program: "-g -G 0 -c"


6. The debugged program:


   a.c:

int a()
{
  return 0;
}

int __attribute__ ((section ("faraway"))) b()
{
  return 1;
}

int c()
{
  return 2;
}


   b.c:

int d()
{
  return 3;
}

int main()
{
  a(); b(); c(); d();
  return 4;
}


7. Compile a.c with DWARF2 debugging info and b.c without any debugging info:
 gcc -gdwarf-2 -O0 -o a.o a.c
 gcc -O2 -o b.o b.c

And link it together:
 gcc -o ab a.o b.o

Run GDB and try to set breakpoint on the function main (or d):
(gdb) b main
Breakpoint 1 at ... file a.c, line 14

But with DWARF1 debugging info we get the correct situation:
(gdb) b main
Breakpoint 1 at ...

8. I suppose that the cause of the problem is that we use this code in the
file dwarf2read.c:
...
static char *
scan_partial_symbols (char *info_ptr, struct objfile *objfile,
		      CORE_ADDR *lowpc, CORE_ADDR *highpc,
		      const struct comp_unit_head *cu_header,
		      const char *namespace)
{
...
  struct partial_die_info pdi;
...
	  switch (pdi.tag)
	    {
	    case DW_TAG_subprogram:
	      if (pdi.has_pc_info)
		{
		  if (pdi.lowpc < *lowpc)
		    {
		      *lowpc = pdi.lowpc;
		    }
		  if (pdi.highpc > *highpc)
		    {
		      *highpc = pdi.highpc;
		    }
		  if (!pdi.is_declaration)
		    {
		      add_partial_symbol (&pdi, objfile, cu_header, namespace);
		    }
		}
	      break;
...

In our case, section "faraway" based after ".text" and so
addresses of the functions d and main "belongs" to the "a.c"
compilation unit. But it false!

We need to correct this problem. I think that we must search through
the "ranges" table and get proper ranges from there.


Best regards,
Konstantin Kostyuhin

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