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[RFA] misc dwarf2 cleanup
- From: dje at google dot com (Doug Evans)
- To: gdb-patches at sourceware dot org
- Date: Mon, 29 Sep 2008 13:45:13 -0700 (PDT)
- Subject: [RFA] misc dwarf2 cleanup
Hi. This patch makes four changes to dwarf2read.c:
1) Use unsigned int consistently for dwarf section offsets and sizes.
Daniel suggested dwarf_off_t but I went with unsigned int for now.
It's a _far_ smaller change, and since the type is internal to
dwarf2read.c making more extensive changes didn't seem compelling
(at least at this point in time).
2) Make read_initial_length do only that: read the initial length and
not also modify cu_header.
I added a new function read_checked_initial_length_and_offset
for dwarf_decode_line_header.
3) Remove unused arg `cu' from dwarf2_get_ref_die_offset.
4) Unconditionally support DW_AT_MIPS_* in pretty printing.
[except DW_AT_MIPS_fde which collides with DW_AT_HP_block_index]
DW_AT_MIPS_linkage_name was showing up as unknown.
I realize we want it to go away, but while it's there pretty-printers
should handle it.
Ok to check in?
2008-09-29 Doug Evans <dje@google.com>
* dwarf2read.c (comp_unit_head): Use unsigned int consistently
for dwarf section offsets and sizes.
(dwarf2_cu): Ditto.
(dwarf2_per_cu_data): Ditto.
(create_all_comp_units): Change offset to unsigned int.
(load_full_comp_unit,find_partial_die_in_comp_unit,find_partial_die,
dwarf2_find_containing_comp_unit,dwarf2_find_comp_unit): Ditto.
* dwarf2read.c (read_initial_length): Delete cu_header arg.
All callers updated.
(read_checked_initial_length_and_offset): New function.
(read_offset_1): New function.
(read_offset): Call it.
(dwarf_decode_line_header): Call read_checked_initial_length_and_offset
instead of read_initial_length. Call read_offset_1 instead of
read_offset.
* dwarf2read.c (dwarf2_get_ref_die_offset): Remove unused arg `cu'.
All callers updated.
* dwarf2read.c (dwarf_attr_name): Unconditionally support all
DW_AT_MIPS_* except DW_AT_MIPS_fde which collides with
DW_AT_HP_block_index.
Index: dwarf2read.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2read.c,v
retrieving revision 1.284
diff -u -p -u -p -r1.284 dwarf2read.c
--- dwarf2read.c 23 Sep 2008 17:36:51 -0000 1.284
+++ dwarf2read.c 29 Sep 2008 20:43:08 -0000
@@ -231,7 +231,7 @@ asection *dwarf_eh_frame_section;
translation, looks like this. */
struct comp_unit_head
{
- unsigned long length;
+ unsigned int length;
short version;
unsigned char addr_size;
unsigned char signed_addr_p;
@@ -296,7 +296,7 @@ struct dwarf2_cu
htab_t partial_dies;
/* `.debug_ranges' offset for this `DW_TAG_compile_unit' DIE. */
- unsigned long ranges_offset;
+ unsigned int ranges_offset;
/* Storage for things with the same lifetime as this read-in compilation
unit, including partial DIEs. */
@@ -361,12 +361,12 @@ struct dwarf2_per_cu_data
/* The start offset and length of this compilation unit. 2**30-1
bytes should suffice to store the length of any compilation unit
- if it doesn't, GDB will fall over anyway. */
- unsigned long offset;
- unsigned long length : 30;
+ unsigned int offset;
+ unsigned int length : 30;
/* Flag indicating this compilation unit will be read in before
any of the current compilation units are processed. */
- unsigned long queued : 1;
+ unsigned int queued : 1;
/* This flag will be set if we need to load absolutely all DIEs
for this compilation unit, instead of just the ones we think
@@ -796,7 +796,7 @@ static gdb_byte *read_partial_die (struc
struct abbrev_info *abbrev, unsigned int,
bfd *, gdb_byte *, struct dwarf2_cu *);
-static struct partial_die_info *find_partial_die (unsigned long,
+static struct partial_die_info *find_partial_die (unsigned int,
struct dwarf2_cu *);
static void fixup_partial_die (struct partial_die_info *,
@@ -824,11 +824,16 @@ static unsigned long read_8_bytes (bfd *
static CORE_ADDR read_address (bfd *, gdb_byte *ptr, struct dwarf2_cu *,
unsigned int *);
-static LONGEST read_initial_length (bfd *, gdb_byte *,
- struct comp_unit_head *, unsigned int *);
+static LONGEST read_initial_length (bfd *, gdb_byte *, unsigned int *);
+
+static LONGEST read_checked_initial_length_and_offset
+ (bfd *, gdb_byte *, const struct comp_unit_head *,
+ unsigned int *, unsigned int *);
static LONGEST read_offset (bfd *, gdb_byte *, const struct comp_unit_head *,
- unsigned int *);
+ unsigned int *);
+
+static LONGEST read_offset_1 (bfd *, gdb_byte *, unsigned int);
static gdb_byte *read_n_bytes (bfd *, gdb_byte *, unsigned int);
@@ -994,8 +999,7 @@ static void dump_die_list (struct die_in
static void store_in_ref_table (struct die_info *,
struct dwarf2_cu *);
-static unsigned int dwarf2_get_ref_die_offset (struct attribute *,
- struct dwarf2_cu *);
+static unsigned int dwarf2_get_ref_die_offset (struct attribute *);
static int dwarf2_get_attr_constant_value (struct attribute *, int);
@@ -1039,10 +1043,10 @@ static hashval_t partial_die_hash (const
static int partial_die_eq (const void *item_lhs, const void *item_rhs);
static struct dwarf2_per_cu_data *dwarf2_find_containing_comp_unit
- (unsigned long offset, struct objfile *objfile);
+ (unsigned int offset, struct objfile *objfile);
static struct dwarf2_per_cu_data *dwarf2_find_comp_unit
- (unsigned long offset, struct objfile *objfile);
+ (unsigned int offset, struct objfile *objfile);
static void free_one_comp_unit (void *);
@@ -1294,11 +1298,9 @@ dwarf2_build_psymtabs_easy (struct objfi
pubnames_ptr = pubnames_buffer;
while ((pubnames_ptr - pubnames_buffer) < dwarf2_per_objfile->pubnames_size)
{
- struct comp_unit_head cu_header;
unsigned int bytes_read;
- entry_length = read_initial_length (abfd, pubnames_ptr, &cu_header,
- &bytes_read);
+ entry_length = read_initial_length (abfd, pubnames_ptr, &bytes_read);
pubnames_ptr += bytes_read;
version = read_1_byte (abfd, pubnames_ptr);
pubnames_ptr += 1;
@@ -1323,13 +1325,15 @@ read_comp_unit_head (struct comp_unit_he
{
int signed_addr;
unsigned int bytes_read;
- cu_header->length = read_initial_length (abfd, info_ptr, cu_header,
- &bytes_read);
+
+ cu_header->length = read_initial_length (abfd, info_ptr, &bytes_read);
+ cu_header->initial_length_size = bytes_read;
+ cu_header->offset_size = (bytes_read == 4) ? 4 : 8;
info_ptr += bytes_read;
cu_header->version = read_2_bytes (abfd, info_ptr);
info_ptr += 2;
cu_header->abbrev_offset = read_offset (abfd, info_ptr, cu_header,
- &bytes_read);
+ &bytes_read);
info_ptr += bytes_read;
cu_header->addr_size = read_1_byte (abfd, info_ptr);
info_ptr += 1;
@@ -1338,6 +1342,7 @@ read_comp_unit_head (struct comp_unit_he
internal_error (__FILE__, __LINE__,
_("read_comp_unit_head: dwarf from non elf file"));
cu_header->signed_addr_p = signed_addr;
+
return info_ptr;
}
@@ -1708,26 +1713,24 @@ create_all_comp_units (struct objfile *o
while (info_ptr < dwarf2_per_objfile->info_buffer + dwarf2_per_objfile->info_size)
{
- struct comp_unit_head cu_header;
+ unsigned int length, initial_length_size;
gdb_byte *beg_of_comp_unit;
struct dwarf2_per_cu_data *this_cu;
- unsigned long offset;
- unsigned int bytes_read;
+ unsigned int offset;
offset = info_ptr - dwarf2_per_objfile->info_buffer;
/* Read just enough information to find out where the next
compilation unit is. */
- cu_header.initial_length_size = 0;
- cu_header.length = read_initial_length (objfile->obfd, info_ptr,
- &cu_header, &bytes_read);
+ length = read_initial_length (objfile->obfd, info_ptr,
+ &initial_length_size);
/* Save the compilation unit for later lookup. */
this_cu = obstack_alloc (&objfile->objfile_obstack,
sizeof (struct dwarf2_per_cu_data));
memset (this_cu, 0, sizeof (*this_cu));
this_cu->offset = offset;
- this_cu->length = cu_header.length + cu_header.initial_length_size;
+ this_cu->length = length + initial_length_size;
if (n_comp_units == n_allocated)
{
@@ -2331,7 +2334,7 @@ skip_one_die (gdb_byte *info_ptr, struct
complaint (&symfile_complaints, _("ignoring absolute DW_AT_sibling"));
else
return dwarf2_per_objfile->info_buffer
- + dwarf2_get_ref_die_offset (&attr, cu);
+ + dwarf2_get_ref_die_offset (&attr);
}
/* If it isn't DW_AT_sibling, skip this attribute. */
@@ -2594,7 +2597,7 @@ load_full_comp_unit (struct dwarf2_per_c
{
bfd *abfd = objfile->obfd;
struct dwarf2_cu *cu;
- unsigned long offset;
+ unsigned int offset;
gdb_byte *info_ptr;
struct cleanup *back_to, *free_cu_cleanup;
struct attribute *attr;
@@ -5869,7 +5872,7 @@ read_partial_die (struct partial_die_inf
case DW_AT_specification:
case DW_AT_extension:
part_die->has_specification = 1;
- part_die->spec_offset = dwarf2_get_ref_die_offset (&attr, cu);
+ part_die->spec_offset = dwarf2_get_ref_die_offset (&attr);
break;
case DW_AT_sibling:
/* Ignore absolute siblings, they might point outside of
@@ -5878,7 +5881,7 @@ read_partial_die (struct partial_die_inf
complaint (&symfile_complaints, _("ignoring absolute DW_AT_sibling"));
else
part_die->sibling = dwarf2_per_objfile->info_buffer
- + dwarf2_get_ref_die_offset (&attr, cu);
+ + dwarf2_get_ref_die_offset (&attr);
break;
case DW_AT_stmt_list:
part_die->has_stmt_list = 1;
@@ -5938,7 +5941,7 @@ read_partial_die (struct partial_die_inf
/* Find a cached partial DIE at OFFSET in CU. */
static struct partial_die_info *
-find_partial_die_in_comp_unit (unsigned long offset, struct dwarf2_cu *cu)
+find_partial_die_in_comp_unit (unsigned int offset, struct dwarf2_cu *cu)
{
struct partial_die_info *lookup_die = NULL;
struct partial_die_info part_die;
@@ -5952,7 +5955,7 @@ find_partial_die_in_comp_unit (unsigned
/* Find a partial DIE at OFFSET, which may or may not be in CU. */
static struct partial_die_info *
-find_partial_die (unsigned long offset, struct dwarf2_cu *cu)
+find_partial_die (unsigned int offset, struct dwarf2_cu *cu)
{
struct dwarf2_per_cu_data *per_cu = NULL;
struct partial_die_info *pd = NULL;
@@ -6010,7 +6013,7 @@ find_partial_die (unsigned long offset,
if (pd == NULL)
internal_error (__FILE__, __LINE__,
- _("could not find partial DIE 0x%lx in cache [from module %s]\n"),
+ _("could not find partial DIE 0x%x in cache [from module %s]\n"),
offset, bfd_get_filename (cu->objfile->obfd));
return pd;
}
@@ -6368,12 +6371,7 @@ read_address (bfd *abfd, gdb_byte *buf,
The value returned via bytes_read should be used to increment the
relevant pointer after calling read_initial_length().
-
- As a side effect, this function sets the fields initial_length_size
- and offset_size in cu_header to the values appropriate for the
- length field. (The format of the initial length field determines
- the width of file offsets to be fetched later with read_offset().)
-
+
[ Note: read_initial_length() and read_offset() are based on the
document entitled "DWARF Debugging Information Format", revision
3, draft 8, dated November 19, 2001. This document was obtained
@@ -6391,8 +6389,7 @@ read_address (bfd *abfd, gdb_byte *buf,
] */
static LONGEST
-read_initial_length (bfd *abfd, gdb_byte *buf, struct comp_unit_head *cu_header,
- unsigned int *bytes_read)
+read_initial_length (bfd *abfd, gdb_byte *buf, unsigned int *bytes_read)
{
LONGEST length = bfd_get_32 (abfd, buf);
@@ -6412,22 +6409,34 @@ read_initial_length (bfd *abfd, gdb_byte
*bytes_read = 4;
}
- if (cu_header)
- {
- gdb_assert (cu_header->initial_length_size == 0
- || cu_header->initial_length_size == 4
- || cu_header->initial_length_size == 8
- || cu_header->initial_length_size == 12);
+ return length;
+}
- if (cu_header->initial_length_size != 0
- && cu_header->initial_length_size != *bytes_read)
- complaint (&symfile_complaints,
- _("intermixed 32-bit and 64-bit DWARF sections"));
+/* Cover function for read_initial_length.
+ Returns the length of the object at BUF, and stores the size of the
+ initial length in *BYTES_READ and stores the size that offsets will be in
+ *OFFSET_SIZE.
+ If the initial length size is not equivalent to that specified in
+ CU_HEADER then issue a complaint.
+ This is useful when reading non-comp-unit headers. */
- cu_header->initial_length_size = *bytes_read;
- cu_header->offset_size = (*bytes_read == 4) ? 4 : 8;
- }
+static LONGEST
+read_checked_initial_length_and_offset (bfd *abfd, gdb_byte *buf,
+ const struct comp_unit_head *cu_header,
+ unsigned int *bytes_read,
+ unsigned int *offset_size)
+{
+ LONGEST length = read_initial_length (abfd, buf, bytes_read);
+
+ gdb_assert (cu_header->initial_length_size == 4
+ || cu_header->initial_length_size == 8
+ || cu_header->initial_length_size == 12);
+
+ if (cu_header->initial_length_size != *bytes_read)
+ complaint (&symfile_complaints,
+ _("intermixed 32-bit and 64-bit DWARF sections"));
+ *offset_size = (*bytes_read == 4) ? 4 : 8;
return length;
}
@@ -6438,21 +6447,29 @@ static LONGEST
read_offset (bfd *abfd, gdb_byte *buf, const struct comp_unit_head *cu_header,
unsigned int *bytes_read)
{
+ LONGEST offset = read_offset_1 (abfd, buf, cu_header->offset_size);
+ *bytes_read = cu_header->offset_size;
+ return offset;
+}
+
+/* Read an offset from the data stream. */
+
+static LONGEST
+read_offset_1 (bfd *abfd, gdb_byte *buf, unsigned int offset_size)
+{
LONGEST retval = 0;
- switch (cu_header->offset_size)
+ switch (offset_size)
{
case 4:
retval = bfd_get_32 (abfd, buf);
- *bytes_read = 4;
break;
case 8:
retval = bfd_get_64 (abfd, buf);
- *bytes_read = 8;
break;
default:
internal_error (__FILE__, __LINE__,
- _("read_offset: bad switch [in module %s]"),
+ _("read_offset_1: bad switch [in module %s]"),
bfd_get_filename (abfd));
}
@@ -6490,8 +6507,7 @@ read_indirect_string (bfd *abfd, gdb_byt
const struct comp_unit_head *cu_header,
unsigned int *bytes_read_ptr)
{
- LONGEST str_offset = read_offset (abfd, buf, cu_header,
- bytes_read_ptr);
+ LONGEST str_offset = read_offset (abfd, buf, cu_header, bytes_read_ptr);
if (dwarf2_per_objfile->str_buffer == NULL)
{
@@ -6790,7 +6806,7 @@ dwarf_decode_line_header (unsigned int o
struct cleanup *back_to;
struct line_header *lh;
gdb_byte *line_ptr;
- unsigned int bytes_read;
+ unsigned int bytes_read, offset_size;
int i;
char *cur_dir, *cur_file;
@@ -6817,7 +6833,8 @@ dwarf_decode_line_header (unsigned int o
/* Read in the header. */
lh->total_length =
- read_initial_length (abfd, line_ptr, &cu->header, &bytes_read);
+ read_checked_initial_length_and_offset (abfd, line_ptr, &cu->header,
+ &bytes_read, &offset_size);
line_ptr += bytes_read;
if (line_ptr + lh->total_length > (dwarf2_per_objfile->line_buffer
+ dwarf2_per_objfile->line_size))
@@ -6828,8 +6845,8 @@ dwarf_decode_line_header (unsigned int o
lh->statement_program_end = line_ptr + lh->total_length;
lh->version = read_2_bytes (abfd, line_ptr);
line_ptr += 2;
- lh->header_length = read_offset (abfd, line_ptr, &cu->header, &bytes_read);
- line_ptr += bytes_read;
+ lh->header_length = read_offset_1 (abfd, line_ptr, offset_size);
+ line_ptr += offset_size;
lh->minimum_instruction_length = read_1_byte (abfd, line_ptr);
line_ptr += 1;
lh->default_is_stmt = read_1_byte (abfd, line_ptr);
@@ -8401,10 +8418,11 @@ dwarf_attr_name (unsigned attr)
return "DW_AT_pure";
case DW_AT_recursive:
return "DW_AT_recursive";
-#ifdef MIPS
/* SGI/MIPS extensions. */
+#ifdef MIPS /* collides with DW_AT_HP_block_index */
case DW_AT_MIPS_fde:
return "DW_AT_MIPS_fde";
+#endif
case DW_AT_MIPS_loop_begin:
return "DW_AT_MIPS_loop_begin";
case DW_AT_MIPS_tail_loop_begin:
@@ -8425,10 +8443,11 @@ dwarf_attr_name (unsigned attr)
return "DW_AT_MIPS_clone_origin";
case DW_AT_MIPS_has_inlines:
return "DW_AT_MIPS_has_inlines";
-#endif
/* HP extensions. */
+#ifndef MIPS /* collides with DW_AT_MIPS_fde */
case DW_AT_HP_block_index:
return "DW_AT_HP_block_index";
+#endif
case DW_AT_HP_unmodifiable:
return "DW_AT_HP_unmodifiable";
case DW_AT_HP_actuals_stmt_list:
@@ -9115,7 +9134,7 @@ store_in_ref_table (struct die_info *die
}
static unsigned int
-dwarf2_get_ref_die_offset (struct attribute *attr, struct dwarf2_cu *cu)
+dwarf2_get_ref_die_offset (struct attribute *attr)
{
unsigned int result = 0;
@@ -9195,7 +9214,7 @@ follow_die_ref (struct die_info *src_die
struct die_info temp_die;
struct dwarf2_cu *target_cu, *cu = *ref_cu;
- offset = dwarf2_get_ref_die_offset (attr, cu);
+ offset = dwarf2_get_ref_die_offset (attr);
if (DW_ADDR (attr) < cu->header.offset
|| DW_ADDR (attr) >= cu->header.offset + cu->header.length)
@@ -10038,7 +10057,7 @@ dwarf2_per_cu_addr_size (struct dwarf2_p
DIE at OFFSET. Raises an error on failure. */
static struct dwarf2_per_cu_data *
-dwarf2_find_containing_comp_unit (unsigned long offset,
+dwarf2_find_containing_comp_unit (unsigned int offset,
struct objfile *objfile)
{
struct dwarf2_per_cu_data *this_cu;
@@ -10070,7 +10089,7 @@ dwarf2_find_containing_comp_unit (unsign
this_cu = dwarf2_per_objfile->all_comp_units[low];
if (low == dwarf2_per_objfile->n_comp_units - 1
&& offset >= this_cu->offset + this_cu->length)
- error (_("invalid dwarf2 offset %ld"), offset);
+ error (_("invalid dwarf2 offset %u"), offset);
gdb_assert (offset < this_cu->offset + this_cu->length);
return this_cu;
}
@@ -10080,12 +10099,12 @@ dwarf2_find_containing_comp_unit (unsign
OFFSET. Raises an error on failure. */
static struct dwarf2_per_cu_data *
-dwarf2_find_comp_unit (unsigned long offset, struct objfile *objfile)
+dwarf2_find_comp_unit (unsigned int offset, struct objfile *objfile)
{
struct dwarf2_per_cu_data *this_cu;
this_cu = dwarf2_find_containing_comp_unit (offset, objfile);
if (this_cu->offset != offset)
- error (_("no compilation unit with offset %ld."), offset);
+ error (_("no compilation unit with offset %u."), offset);
return this_cu;
}