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[gdb/symtab] Remove superfluous end-of-sequence marker

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While working on PR26935 I noticed that when running test-case
gdb.base/morestack.exp with target board unix/-m32/-fPIE/-pie and ld linker,
I get this linetable fragment for morestack.S using readelf -wL:
...
CU: ../../../../libgcc/config/i386/morestack.S:
Line number    Starting address    View    Stmt
109               0xc9c               x
  ...
838               0xe03               x
  -               0xe04

636                   0               x
637                 0x3               x
  -                 0x4
...
but with "maint info line-table" I get:
...
INDEX  LINE   ADDRESS            IS-STMT
0      END    0x00000004         Y
1      109    0x00000c9c         Y
  ...
110    838    0x00000e03         Y
111    END    0x00000e04         Y
...

So, apparently the entries with addresses 0x0 and 0x3 are filtered out
because the addresses are out of range, but the same doesn't happen with the
end-of-seq terminator.

Fix this by filtering out end-of-seq terminators that do not actually
terminate anything.

Tested on x86_64-linux.

gdb/ChangeLog:

2021-01-04  Tom de Vries  <tdevries@suse.de>

	* buildsym.c (buildsym_compunit::record_line): Filter out end-of-seq
	terminators that do not terminate anything.

gdb/testsuite/ChangeLog:

2021-01-04  Tom de Vries  <tdevries@suse.de>

	* gdb.dwarf2/dw2-out-of-range-end-of-seq.exp: New file.
This commit is contained in:
Tom de Vries
2021-01-04 19:34:25 +01:00
parent 3ec3145c5d
commit e4ad960a57
4 changed files with 110 additions and 2 deletions
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9
gdb/buildsym.c
View File

@@ -707,13 +707,18 @@ buildsym_compunit::record_line (struct subfile *subfile, int line,
anyway. */
if (line == 0)
{
struct linetable_entry *last = nullptr;
while (subfile->line_vector->nitems > 0)
{
e = subfile->line_vector->item + subfile->line_vector->nitems - 1;
if (e->pc != pc)
last = subfile->line_vector->item + subfile->line_vector->nitems - 1;
if (last->pc != pc)
break;
subfile->line_vector->nitems--;
}
/* Ignore an end-of-sequence marker marking an empty sequence. */
if (last == nullptr || last->line == 0)
return;
}
e = subfile->line_vector->item + subfile->line_vector->nitems++;