The following patch fixes a problem on ia64. In dwarf2read.c,
dwarf_decode_lines(), the function check_cu_functions() is called
to check for a specific scenario caused by gcc.
The function takes an address and returns an address. In some
cases, it will return the lowpc value of the function rather than
the address that was input.
On the ia64, this causes problems because the line table info spit
out by the compiler is often specified with relative addresses.
As well, ia64 addresses are special as they encode a slot number which goes
0, 1, 2, then skips to the next quadword boundary. For example,
0x00, 0x01, 0x02, 0x10, 0x11, 0x12, 0x20, 0x21, 0x22, ...
Addresses such as 0x0e or 0x0f are invalid and cause an error to
occur if, say, a breakpoint was attempted to be inserted there.
Now, in dwarf_decode_lines(), if we update the address counter when we call
check_cu_functions(), adding relative offsets in subsequent entries often results in
invalid addresses.
This patch makes it so the check_cu_functions() call is only used to
alter the address passed to record_line(); the calculated address is left untouched
so subsequent relative operations result in valid results.
Tested on ia64 and x86.
Ok to commit?
-- Jeff J.
2003-05-05 Jeff Johnston <jjohnstn@redhat.com>
* dwarf2read.c (dwarf_decode_lines): Only use output of check_cu_functions()
when calling record_line(). Do not update the current address.
Index: dwarf2read.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2read.c,v
retrieving revision 1.90
diff -u -p -r1.90 dwarf2read.c
--- dwarf2read.c 15 Apr 2003 23:07:11 -0000 1.90
+++ dwarf2read.c 5 May 2003 21:55:26 -0000
@@ -4878,8 +4878,8 @@ dwarf_decode_lines (struct line_header *
* lh->minimum_instruction_length;
line += lh->line_base + (adj_opcode % lh->line_range);
/* append row to matrix using current values */
- address = check_cu_functions (address);
- record_line (current_subfile, line, address);
+ record_line (current_subfile, line,
+ check_cu_functions (address));
basic_block = 1;
}
else switch (op_code)
@@ -4925,8 +4925,8 @@ dwarf_decode_lines (struct line_header *
}
break;
case DW_LNS_copy:
- address = check_cu_functions (address);
- record_line (current_subfile, line, address);
+ record_line (current_subfile, line,
+ check_cu_functions (address));
basic_block = 0;
break;
case DW_LNS_advance_pc: