Patch to handle DWARF2 DW_FORM_indirect

Keith.Walker
2001-11-13T17:48:52Z

The DWARF2 specification allows the form of attributes to be described
"inline" with DW_FORM_indirect rather than the form being specified in a
separate abbreviation table. The following patch adds support for
DW_FORM_indirect in BFD, binutils and GDB.

If there are no objections, can this patch be approved and applied by the
GDB and binutils maintainers.

Keith

Index: bfd/ChangeLog
===================================================================
RCS file: /cvs/src/src/bfd/ChangeLog,v
retrieving revision 1.1156
diff -u -r1.1156 ChangeLog
--- ChangeLog 2001/11/13 03:52:25 1.1156
+++ ChangeLog 2001/11/13 17:23:31
@@ -1,3 +1,9 @@
+2001-11-13 Keith Walker <keith.walker@arm.com>
+
+ * dwarf2.c (read_attribute_value): New Function to handle
+ DW_FORM_indirect
+ (read_attribute): uses read_attribute_value
+
2001-11-13 John Marshall <jmarshall@acm.org>
Alan Modra <amodra@bigpond.net.au>

Index: bfd/dwarf2.c
===================================================================
RCS file: /cvs/src/src/bfd/dwarf2.c,v
retrieving revision 1.24
diff -u -r1.24 dwarf2.c
--- dwarf2.c 2001/10/06 10:01:09 1.24
+++ dwarf2.c 2001/11/13 17:23:47
@@ -216,6 +216,9 @@
static char *read_attribute
PARAMS ((struct attribute *, struct attr_abbrev *,
struct comp_unit *, char *));
+static char *read_attribute_value
+ PARAMS ((struct attribute *, unsigned,
+ struct comp_unit *, char *));
static void add_line_info
PARAMS ((struct line_info_table *, bfd_vma, char *,
unsigned int, unsigned int, int));
@@ -564,12 +567,12 @@
return abbrevs;
}

-/* Read an attribute described by an abbreviated attribute. */
+/* Read an attribute value described by an attribute form. */

static char *
-read_attribute (attr, abbrev, unit, info_ptr)
+read_attribute_value (attr, form, unit, info_ptr)
struct attribute *attr;
- struct attr_abbrev *abbrev;
+ unsigned form;
struct comp_unit *unit;
char *info_ptr;
{
@@ -578,10 +581,9 @@
struct dwarf_block *blk;
bfd_size_type amt;

- attr->name = abbrev->name;
- attr->form = abbrev->form;
+ attr->form = form;

- switch (abbrev->form)
+ switch (form)
{
case DW_FORM_addr:
case DW_FORM_ref_addr:
@@ -676,13 +678,31 @@
DW_UNSND (attr) = read_unsigned_leb128 (abfd, info_ptr, &bytes_read);
info_ptr += bytes_read;
break;
- case DW_FORM_strp:
case DW_FORM_indirect:
+ form = read_unsigned_leb128 (abfd, info_ptr, &bytes_read);
+ info_ptr += bytes_read;
+ info_ptr = read_attribute_value (attr, form, unit, info_ptr);
+ break;
+ case DW_FORM_strp:
default:
(*_bfd_error_handler) (_("Dwarf Error: Invalid or unhandled FORM
value: %d."),
- abbrev->form);
+ form);
bfd_set_error (bfd_error_bad_value);
}
+ return info_ptr;
+}
+
+/* Read an attribute described by an abbreviated attribute. */
+
+static char *
+read_attribute (attr, abbrev, unit, info_ptr)
+ struct attribute *attr;
+ struct attr_abbrev *abbrev;
+ struct comp_unit *unit;
+ char *info_ptr;
+{
+ attr->name = abbrev->name;
+ info_ptr = read_attribute_value (attr, abbrev->form, unit, info_ptr);
return info_ptr;
}

Index: binutils/ChangeLog
===================================================================
RCS file: /cvs/src/src/binutils/ChangeLog,v
retrieving revision 1.365
diff -u -r1.365 ChangeLog
--- ChangeLog 2001/11/12 16:17:38 1.365
+++ ChangeLog 2001/11/13 17:23:56
@@ -1,3 +1,8 @@
+2001-11-13 Keith Walker <keith.walker@arm.com>
+ * readelf.c (read_and_display_attr_value): New function to
+ handle DW_FORM_indirect
+ (read_and_display_attr): uses read_and_display_attr_value
+
2001-11-12 * Steven J. Hill <sjhill@realitydiluted.com>

* bucomm.c (make_tempname): Use mkstemp in place of mktemp.

Index: binutils/readelf.c
===================================================================
RCS file: /cvs/src/src/binutils/readelf.c,v
retrieving revision 1.131
diff -u -r1.131 readelf.c
--- readelf.c 2001/11/10 00:55:48 1.131
+++ readelf.c 2001/11/13 17:24:04
@@ -231,6 +231,7 @@
static void add_abbrev PARAMS ((unsigned
long, unsigned long, int));
static void add_abbrev_attr PARAMS ((unsigned
long, unsigned long));
static unsigned char * read_and_display_attr PARAMS ((unsigned
long, unsigned long, unsigned char *, unsigned long, unsigned long));
+static unsigned char * read_and_display_attr_value PARAMS ((unsigned
long, unsigned long, unsigned char *, unsigned long, unsigned long));
static unsigned char * display_block PARAMS ((unsigned
char *, unsigned long));
static void decode_location_expression PARAMS ((unsigned
char *, unsigned int, unsigned long));
static void request_dump PARAMS ((unsigned int, int));
@@ -6905,7 +6906,7 @@

static unsigned char *
-read_and_display_attr (attribute, form, data, cu_offset, pointer_size)
+read_and_display_attr_value (attribute, form, data, cu_offset, pointer_size)
unsigned long attribute;
unsigned long form;
unsigned char * data;
@@ -6916,8 +6917,6 @@
unsigned char * block_start = NULL;
int bytes_read;

- printf (" %-18s:", get_AT_name (attribute));
-
switch (form)
{
default:
@@ -6962,6 +6961,13 @@
uvalue = read_leb128 (data, & bytes_read, 0);
data += bytes_read;
break;
+
+ case DW_FORM_indirect:
+ form = read_leb128 (data, & bytes_read, 0);
+ data += bytes_read;
+ printf (" %s", get_FORM_name (form));
+ return read_and_display_attr_value (attribute, form, data, cu_offset,
+ pointer_size);
}

switch (form)
@@ -7037,7 +7043,7 @@
break;

case DW_FORM_indirect:
- warn (_("Unable to handle FORM: %d"), form);
+ /* handled above */
break;

default:
@@ -7196,6 +7202,20 @@
break;
}

+ return data;
+}
+
+static unsigned char *
+read_and_display_attr (attribute, form, data, cu_offset, pointer_size)
+ unsigned long attribute;
+ unsigned long form;
+ unsigned char * data;
+ unsigned long cu_offset;
+ unsigned long pointer_size;
+{
+ printf (" %-18s:", get_AT_name (attribute));
+ data = read_and_display_attr_value (attribute, form, data, cu_offset,
+ pointer_size);
printf ("\n");
return data;
}

Index: gdb/ChangeLog
===================================================================
RCS file: /cvs/src/src/gdb/ChangeLog,v
retrieving revision 1.1758
diff -u -r1.1758 ChangeLog
--- ChangeLog 2001/11/13 03:10:33 1.1758
+++ ChangeLog 2001/11/13 17:24:15
@@ -1,3 +1,8 @@
+2001-11-13 Keith Walker <keith.walker@arm.com>
+ * dwarf2read.c (read_attribute_value): New function to handle
+ DW_FORM_indirect
+ (read_attribute): uses read_attribute_value
+
2001-11-10 Andrew Cagney <ac131313@redhat.com>

* config/i960/tm-nindy960.h (REGISTER_CONVERTIBLE)

Index: gdb/dwarf2read.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2read.c,v
retrieving revision 1.34
diff -u -r1.34 dwarf2read.c
--- dwarf2read.c 2001/11/12 20:36:55 1.34
+++ dwarf2read.c 2001/11/13 17:24:25
@@ -593,6 +593,9 @@
static char *read_attribute (struct attribute *, struct attr_abbrev *,
bfd *, char *, const struct comp_unit_head *);

+static char *read_attribute_value (struct attribute *, unsigned,
+ bfd *, char *, const struct comp_unit_head *);
+
static unsigned int read_1_byte (bfd *, char *);

static int read_1_signed_byte (bfd *, char *);
@@ -3333,19 +3336,18 @@
return info_ptr;
}

-/* Read an attribute described by an abbreviated attribute. */
+/* Read an attribute value described by an attribute form. */

static char *
-read_attribute (struct attribute *attr, struct attr_abbrev *abbrev,
+read_attribute_value (struct attribute *attr, unsigned form,
bfd *abfd, char *info_ptr,
const struct comp_unit_head *cu_header)
{
unsigned int bytes_read;
struct dwarf_block *blk;

- attr->name = abbrev->name;
- attr->form = abbrev->form;
- switch (abbrev->form)
+ attr->form = form;
+ switch (form)
{
case DW_FORM_addr:
case DW_FORM_ref_addr:
@@ -3436,15 +3438,30 @@
DW_UNSND (attr) = read_unsigned_leb128 (abfd, info_ptr, &bytes_read);
info_ptr += bytes_read;
break;
- case DW_FORM_strp:
case DW_FORM_indirect:
+ form = read_unsigned_leb128 (abfd, info_ptr, &bytes_read);
+ info_ptr += bytes_read;
+ info_ptr = read_attribute_value (attr, form, abfd, info_ptr, cu_header);
+ break;
+ case DW_FORM_strp:
default:
error ("Dwarf Error: Cannot handle %s in DWARF reader.",
- dwarf_form_name (abbrev->form));
+ dwarf_form_name (form));
}
return info_ptr;
}

+/* Read an attribute described by an abbreviated attribute. */
+
+static char *
+read_attribute (struct attribute *attr, struct attr_abbrev *abbrev,
+ bfd *abfd, char *info_ptr,
+ const struct comp_unit_head *cu_header)
+{
+ attr->name = abbrev->name;
+ return read_attribute_value (attr, abbrev->form, abfd, info_ptr, cu_header);
+}
+
/* read dwarf information from a buffer */

static unsigned int
@@ -5602,7 +5619,9 @@
break;
case DW_FORM_strp: /* we do not support separate string
section yet */
- case DW_FORM_indirect: /* we do not handle indirect yet */
+ case DW_FORM_indirect: /* the reader will have reduced the indirect
+ form to the base type so this form
+ should not occur */
default:
fprintf (stderr, "unsupported attribute form: %d.",
die->attrs[i].form);

Keith Walker keith.walker@arm.com Tel:+44 (1628) 427732
ARM Ltd http://www.arm.com