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[commit] Minimal DW_TAG_partial_unit support
- From: Daniel Jacobowitz <drow at false dot org>
- To: gdb-patches at sourceware dot org
- Date: Thu, 2 Nov 2006 16:36:37 -0500
- Subject: [commit] Minimal DW_TAG_partial_unit support
This patch adds minimal support for DW_TAG_partial_unit. We don't need to
create psymtabs for partial units, or full symtabs; right now the only thing
they'll be used for is any type DIEs referenced with DW_FORM_ref_addr. In
the future we may want imported unit support, too. This patch prevents GDB
from crashing when presented with a DW_TAG_partial_unit; previously we'd
call end_symtab without calling start_symtab, leading to double-freeing
"subfiles".
Tested on arm-none-eabi, as well as with an ARM compiler testcase that uses
DW_TAG_partial_unit, and checked in.
--
Daniel Jacobowitz
CodeSourcery
2006-11-02 Daniel Jacobowitz <dan@codesourcery.com>
* dwarf2read.c (struct dwarf2_per_cu_data): Update comment.
(load_full_comp_unit): Take OBJFILE argument and use it.
(dwarf2_build_psymtabs_hard): Skip partial units.
(process_queue): Pass OBJFILE to load_full_comp_unit. Check
type_hash for read in CUs. Test psymtab for NULL.
Index: gdb/dwarf2read.c
===================================================================
RCS file: /scratch/gcc/repos/src/src/gdb/dwarf2read.c,v
retrieving revision 1.205
diff -u -p -r1.205 dwarf2read.c
--- gdb/dwarf2read.c 11 Oct 2006 15:39:35 -0000 1.205
+++ gdb/dwarf2read.c 2 Nov 2006 20:29:08 -0000
@@ -389,7 +389,9 @@ struct dwarf2_per_cu_data
it. */
htab_t type_hash;
- /* The partial symbol table associated with this compilation unit. */
+ /* The partial symbol table associated with this compilation unit,
+ or NULL for partial units (which do not have an associated
+ symtab). */
struct partial_symtab *psymtab;
};
@@ -1066,7 +1068,8 @@ static void reset_die_and_siblings_types
static void create_all_comp_units (struct objfile *);
-static struct dwarf2_cu *load_full_comp_unit (struct dwarf2_per_cu_data *);
+static struct dwarf2_cu *load_full_comp_unit (struct dwarf2_per_cu_data *,
+ struct objfile *);
static void process_full_comp_unit (struct dwarf2_per_cu_data *);
@@ -1470,6 +1473,14 @@ dwarf2_build_psymtabs_hard (struct objfi
info_ptr = read_partial_die (&comp_unit_die, abbrev, bytes_read,
abfd, info_ptr, &cu);
+ if (comp_unit_die.tag == DW_TAG_partial_unit)
+ {
+ info_ptr = (beg_of_comp_unit + cu.header.length
+ + cu.header.initial_length_size);
+ do_cleanups (back_to_inner);
+ continue;
+ }
+
/* Set the language we're debugging */
set_cu_language (comp_unit_die.language, &cu);
@@ -2386,14 +2397,14 @@ process_queue (struct objfile *objfile)
{
/* Read in this compilation unit. This may add new items to
the end of the queue. */
- load_full_comp_unit (item->per_cu);
+ load_full_comp_unit (item->per_cu, objfile);
item->per_cu->cu->read_in_chain = dwarf2_per_objfile->read_in_chain;
dwarf2_per_objfile->read_in_chain = item->per_cu;
/* If this compilation unit has already had full symbols created,
reset the TYPE fields in each DIE. */
- if (item->per_cu->psymtab->readin)
+ if (item->per_cu->type_hash)
reset_die_and_siblings_types (item->per_cu->cu->dies,
item->per_cu->cu);
}
@@ -2402,7 +2413,7 @@ process_queue (struct objfile *objfile)
them, one at a time, removing from the queue as we finish. */
for (item = dwarf2_queue; item != NULL; dwarf2_queue = item = next_item)
{
- if (!item->per_cu->psymtab->readin)
+ if (item->per_cu->psymtab && !item->per_cu->psymtab->readin)
process_full_comp_unit (item->per_cu);
item->per_cu->queued = 0;
@@ -2495,10 +2506,9 @@ psymtab_to_symtab_1 (struct partial_symt
/* Load the DIEs associated with PST and PER_CU into memory. */
static struct dwarf2_cu *
-load_full_comp_unit (struct dwarf2_per_cu_data *per_cu)
+load_full_comp_unit (struct dwarf2_per_cu_data *per_cu, struct objfile *objfile)
{
- struct partial_symtab *pst = per_cu->psymtab;
- bfd *abfd = pst->objfile->obfd;
+ bfd *abfd = objfile->obfd;
struct dwarf2_cu *cu;
unsigned long offset;
gdb_byte *info_ptr;
@@ -2517,7 +2527,7 @@ load_full_comp_unit (struct dwarf2_per_c
/* If an error occurs while loading, release our storage. */
free_cu_cleanup = make_cleanup (free_one_comp_unit, cu);
- cu->objfile = pst->objfile;
+ cu->objfile = objfile;
/* read in the comp_unit header */
info_ptr = read_comp_unit_head (&cu->header, info_ptr, abfd);