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[RFA] comdat types
- From: dje at google dot com (Doug Evans)
- To: gdb-patches at sourceware dot org
- Cc: ccoutant at google dot com
- Date: Fri, 19 Jun 2009 17:04:02 -0700 (PDT)
- Subject: [RFA] comdat types
Hi.
This patch adds support for "comdat types" from dwarf4.
http://wiki.dwarfstd.org/index.php?title=COMDAT_Type_Sections
It requires http://sourceware.org/ml/gdb-patches/2009-06/msg00521.html.
There are no regressions on amd64 or i386 when not using -gdwarf-4.
There are a couple of failures with -gdwarf-4,
I need to revisit them with the latest gcc (the dwarf4 branch)
as they seem like gcc issues.
[specifically gdb.cp/classes.exp, and "info type foo" doesn't print the
source location though it should]
Storing each TU (type unit, a la CU for comp unit) in its own psymtab
may or may not be the right thing to do. Psymtabs are eventually going
away, and doing it this way falls out naturally from the code so I
went with this for now.
Ok to check in?
[It's been painful continually updating this patch.
I'm kinda hoping for a relatively quick review,
though I understand this patch is not small.]
2009-06-19 Doug Evans <dje@google.com>
* dwarf2.h (enum dwarf_tag): Add DW_TAG_type_unit.
(enum dwarf_form): Add DW_FORM_sec_offset, DW_FORM_exprloc,
DW_FORM_flag_present, DW_FORM_sig8.
(enum dwarf_attribute): Add DW_AT_signature, DW_AT_GNU_odr_signature.
Add support for "comdat types" from DWARF4.
* dwarf2read.c (dwarf2_per_objfile): New member types,
signatured_types.
(TYPES_SECTION): New macro.
(dwarf2_per_cu_data): Change size of length field from 30 bits
to 29 bits. New member from_debug_types.
(signatured_type): New struct.
(struct attribute): New union member signatured_type.
(DW_SIGNATURED_TYPE): New macro.
(dwarf2_attr_no_follow): New function.
(read_type_unit_scope): New function.
(follow_die_ref_or_sig, follow_die_sig): New functions.
(dwarf2_locate_sectoins): Handle .debug_types.
(dwarf2_build_psymtabs): Read .debug_types.
(read_type_comp_unit_head): New function.
(hash_type_signature, eq_type_signature): New functions.
(create_debug_types_hash_table): New function.
(lookup_signatured_type): New function.
(process_psymtab_comp_unit): Handle type units too.
(process_type_comp_unit, build_type_psymtabs): New functions.
(dwarf2_build_psymtabs_hard): Call build_type_psymtabs.
(load_partial_comp_unit): Assert not called for a type unit.
(skip_one_die): Handle DW_FORM_sig8.
(queue_comp_unit): Don't call load_full_comp_unit here, or
update read_in_chain.
(psymtab_to_symtab_1): Call read_signatured_type_at_offset for
type units, or load_full_comp_unit for comp units after
queue_comp_unit returns.
(load_full_comp_unit): Assert not called for type units.
(load_full_comp_unit): Update read_in_chain here.
(process_die): Handle DW_TAG_type_unit.
(read_structure_type): Look for signatured types.
(read_enumeration_type): Ditto.
(init_cu_die_reader): Handle .debug_types.
(read_comp_unit): Assert hash not computed yet.
(read_die_and_children): Expand debugging printf to handle .debug_types.
(read_partial_die): Handle DW_TAG_type_unit:
(find_patial_die): Handle .debug_types.
(read_attribute_value): Handle DW_FORM_sig8.
(die_type): Call follow_die_ref_or_sig instead of follow_die_ref.
(die_containing_type): Ditto.
(dwarf_tag_name): Handle DW_TAG_type_unit.
(dwarf_attr_name): Handle DW_AT_signature, DW_GNU_odr_signature.
(dwarf_form_name): Handle DW_FORM_sec_offset, DW_FORM_exprloc,
DW_FORM_flag_present, DW_FORM_sig8.
(dump_die_shallow): Handlel DW_FORM_sig8.
(maybe_queue_comp_unit): Change return type to int from void.
All callers updated.
(follow_die_ref): Handle .debug_types.
(lookup_signatured_type_at_offset): New function.
(read_signatured_type_at_offset): New function.
(read_signatured_type): New function.
Index: ./include/elf/dwarf2.h
===================================================================
RCS file: /cvs/src/src/include/elf/dwarf2.h,v
retrieving revision 1.25
diff -u -p -r1.25 dwarf2.h
--- ./include/elf/dwarf2.h 24 Apr 2009 18:28:58 -0000 1.25
+++ ./include/elf/dwarf2.h 19 Jun 2009 23:48:31 -0000
@@ -190,6 +190,8 @@ enum dwarf_tag
DW_TAG_imported_unit = 0x3d,
DW_TAG_condition = 0x3f,
DW_TAG_shared_type = 0x40,
+ /* DWARF 4. */
+ DW_TAG_type_unit = 0x41,
/* SGI/MIPS Extensions. */
DW_TAG_MIPS_loop = 0x4081,
/* HP extensions. See: ftp://ftp.hp.com/pub/lang/tools/WDB/wdb-4.0.tar.gz . */
@@ -239,7 +241,12 @@ enum dwarf_form
DW_FORM_ref4 = 0x13,
DW_FORM_ref8 = 0x14,
DW_FORM_ref_udata = 0x15,
- DW_FORM_indirect = 0x16
+ DW_FORM_indirect = 0x16,
+ /* DWARF 4. */
+ DW_FORM_sec_offset = 0x17,
+ DW_FORM_exprloc = 0x18,
+ DW_FORM_flag_present = 0x19,
+ DW_FORM_sig8 = 0x20
};
/* Attribute names and codes. */
@@ -337,6 +344,8 @@ enum dwarf_attribute
DW_AT_elemental = 0x66,
DW_AT_pure = 0x67,
DW_AT_recursive = 0x68,
+ /* DWARF 4 values. */
+ DW_AT_signature = 0x69,
/* SGI/MIPS extensions. */
DW_AT_MIPS_fde = 0x2001,
DW_AT_MIPS_loop_begin = 0x2002,
@@ -372,6 +381,7 @@ enum dwarf_attribute
DW_AT_body_begin = 0x2105,
DW_AT_body_end = 0x2106,
DW_AT_GNU_vector = 0x2107,
+ DW_AT_GNU_odr_signature = 0x210f,
/* VMS extensions. */
DW_AT_VMS_rtnbeg_pd_address = 0x2201,
/* UPC extension. */
diff -u -p ../../dwarf-cleanup/src/gdb/dwarf2read.c ./gdb/dwarf2read.c
--- ../../dwarf-cleanup/src/gdb/dwarf2read.c 2009-06-18 19:07:07.000000000 -0700
+++ ./gdb/dwarf2read.c 2009-06-19 15:38:07.000000000 -0700
@@ -163,6 +163,7 @@ struct dwarf2_per_objfile
struct dwarf2_section_info macinfo;
struct dwarf2_section_info str;
struct dwarf2_section_info ranges;
+ struct dwarf2_section_info types;
struct dwarf2_section_info frame;
struct dwarf2_section_info eh_frame;
@@ -177,6 +178,10 @@ struct dwarf2_per_objfile
they can be freed later. */
struct dwarf2_per_cu_data *read_in_chain;
+ /* A table mapping .debug_types signatures to its signatured_type entry.
+ This is NULL if the .debug_types section hasn't been read in yet. */
+ htab_t signatured_types;
+
/* A flag indicating wether this objfile has a section loaded at a
VMA of 0. */
int has_section_at_zero;
@@ -198,6 +203,7 @@ static struct dwarf2_per_objfile *dwarf2
#define MACINFO_SECTION "debug_macinfo"
#define STR_SECTION "debug_str"
#define RANGES_SECTION "debug_ranges"
+#define TYPES_SECTION "debug_types"
#define FRAME_SECTION "debug_frame"
#define EH_FRAME_SECTION "eh_frame"
@@ -339,13 +345,13 @@ struct dwarf2_cu
struct dwarf2_per_cu_data
{
- /* The start offset and length of this compilation unit. 2**30-1
+ /* The start offset and length of this compilation unit. 2**29-1
bytes should suffice to store the length of any compilation unit
- if it doesn't, GDB will fall over anyway.
NOTE: Unlike comp_unit_head.length, this length includes
initial_length_size. */
unsigned int offset;
- unsigned int length : 30;
+ unsigned int length : 29;
/* Flag indicating this compilation unit will be read in before
any of the current compilation units are processed. */
@@ -357,6 +363,10 @@ struct dwarf2_per_cu_data
hash table and don't find it. */
unsigned int load_all_dies : 1;
+ /* Non-zero if this CU is from .debug_types.
+ Otherwise it's from .debug_info. */
+ unsigned int from_debug_types : 1;
+
/* Set iff currently read in. */
struct dwarf2_cu *cu;
@@ -372,6 +382,22 @@ struct dwarf2_per_cu_data
struct partial_symtab *psymtab;
};
+/* Entry in the signatured_types hash table. */
+
+struct signatured_type
+{
+ ULONGEST signature;
+
+ /* Offset in .debug_types of the TU (type_unit) for this type. */
+ unsigned int offset;
+
+ /* Offset in .debug_types of the type defined by this TU. */
+ unsigned int type_offset;
+
+ /* The CU(/TU) of this type. */
+ struct dwarf2_per_cu_data per_cu;
+};
+
/* Struct used to pass misc. parameters to read_die_and_children, et. al.
which are used for both .debug_info and .debug_types dies.
All parameters here are unchanging for the life of the call.
@@ -540,6 +566,7 @@ struct attribute
unsigned long unsnd;
long int snd;
CORE_ADDR addr;
+ struct signatured_type *signatured_type;
}
u;
};
@@ -589,6 +616,7 @@ struct function_range
#define DW_BLOCK(attr) ((attr)->u.blk)
#define DW_SND(attr) ((attr)->u.snd)
#define DW_ADDR(attr) ((attr)->u.addr)
+#define DW_SIGNATURED_TYPE(attr) ((attr)->u.signatured_type)
/* Blocks are a bunch of untyped bytes. */
struct dwarf_block
@@ -873,6 +901,10 @@ static void set_cu_language (unsigned in
static struct attribute *dwarf2_attr (struct die_info *, unsigned int,
struct dwarf2_cu *);
+static struct attribute *dwarf2_attr_no_follow (struct die_info *,
+ unsigned int,
+ struct dwarf2_cu *);
+
static int dwarf2_flag_true_p (struct die_info *die, unsigned name,
struct dwarf2_cu *cu);
@@ -923,6 +955,8 @@ static char *typename_concat (struct obs
static void read_file_scope (struct die_info *, struct dwarf2_cu *);
+static void read_type_unit_scope (struct die_info *, struct dwarf2_cu *);
+
static void read_func_scope (struct die_info *, struct dwarf2_cu *);
static void read_lexical_block_scope (struct die_info *, struct dwarf2_cu *);
@@ -1043,10 +1077,24 @@ static unsigned int dwarf2_get_ref_die_o
static int dwarf2_get_attr_constant_value (struct attribute *, int);
+static struct die_info *follow_die_ref_or_sig (struct die_info *,
+ struct attribute *,
+ struct dwarf2_cu **);
+
static struct die_info *follow_die_ref (struct die_info *,
struct attribute *,
struct dwarf2_cu **);
+static struct die_info *follow_die_sig (struct die_info *,
+ struct attribute *,
+ struct dwarf2_cu **);
+
+static void read_signatured_type_at_offset (struct objfile *objfile,
+ unsigned int offset);
+
+static void read_signatured_type (struct objfile *,
+ struct signatured_type *type_sig);
+
/* memory allocation interface */
static struct dwarf_block *dwarf_alloc_block (struct dwarf2_cu *);
@@ -1214,6 +1262,11 @@ dwarf2_locate_sections (bfd *abfd, asect
dwarf2_per_objfile->ranges.asection = sectp;
dwarf2_per_objfile->ranges.size = bfd_get_section_size (sectp);
}
+ else if (section_is_p (sectp->name, TYPES_SECTION))
+ {
+ dwarf2_per_objfile->types.asection = sectp;
+ dwarf2_per_objfile->types.size = bfd_get_section_size (sectp);
+ }
if ((bfd_get_section_flags (abfd, sectp) & SEC_LOAD)
&& bfd_section_vma (abfd, sectp) == 0)
@@ -1413,6 +1466,7 @@ dwarf2_build_psymtabs (struct objfile *o
dwarf2_read_section (objfile, &dwarf2_per_objfile->str);
dwarf2_read_section (objfile, &dwarf2_per_objfile->macinfo);
dwarf2_read_section (objfile, &dwarf2_per_objfile->ranges);
+ dwarf2_read_section (objfile, &dwarf2_per_objfile->types);
dwarf2_read_section (objfile, &dwarf2_per_objfile->loc);
dwarf2_read_section (objfile, &dwarf2_per_objfile->eh_frame);
dwarf2_read_section (objfile, &dwarf2_per_objfile->frame);
@@ -1551,6 +1605,29 @@ partial_read_comp_unit_head (struct comp
return info_ptr;
}
+/* Read in the types comp unit header information from .debug_types entry at
+ types_ptr. The result is a pointer to one past the end of the header. */
+
+static gdb_byte *
+read_type_comp_unit_head (struct comp_unit_head *cu_header,
+ ULONGEST *signature,
+ gdb_byte *types_ptr, bfd *abfd)
+{
+ unsigned int bytes_read;
+ gdb_byte *initial_types_ptr = types_ptr;
+
+ cu_header->offset = types_ptr - dwarf2_per_objfile->types.buffer;
+
+ types_ptr = read_comp_unit_head (cu_header, types_ptr, abfd);
+
+ *signature = read_8_bytes (abfd, types_ptr);
+ types_ptr += 8;
+ types_ptr += cu_header->offset_size;
+ cu_header->first_die_offset = types_ptr - initial_types_ptr;
+
+ return types_ptr;
+}
+
/* Allocate a new partial symtab for file named NAME and mark this new
partial symtab as being an include of PST. */
@@ -1610,9 +1687,137 @@ dwarf2_build_include_psymtabs (struct dw
free_line_header (lh);
}
-/* Subroutine of dwarf2_build_psymtabs_hard to simplify it.
+static hashval_t
+hash_type_signature (const void *item)
+{
+ const struct signatured_type *type_sig = item;
+ /* This drops the top 32 bits of the signature, but is ok for a hash. */
+ return type_sig->signature;
+}
+
+static int
+eq_type_signature (const void *item_lhs, const void *item_rhs)
+{
+ const struct signatured_type *lhs = item_lhs;
+ const struct signatured_type *rhs = item_rhs;
+ return lhs->signature == rhs->signature;
+}
+
+/* Create the hash table of all entries in the .debug_types section.
+ The result is zero if there is an error (e.g. missing .debug_types section),
+ otherwise non-zero. */
+
+static int
+create_debug_types_hash_table (struct objfile *objfile)
+{
+ gdb_byte *info_ptr = dwarf2_per_objfile->types.buffer;
+ htab_t types_htab;
+
+ if (info_ptr == NULL)
+ {
+ dwarf2_per_objfile->signatured_types = NULL;
+ return 0;
+ }
+
+ types_htab = htab_create_alloc_ex (41,
+ hash_type_signature,
+ eq_type_signature,
+ NULL,
+ &objfile->objfile_obstack,
+ hashtab_obstack_allocate,
+ dummy_obstack_deallocate);
+
+ if (dwarf2_die_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, "Signatured types:\n");
+ }
+
+ while (info_ptr < dwarf2_per_objfile->types.buffer + dwarf2_per_objfile->types.size)
+ {
+ unsigned int offset;
+ unsigned int offset_size;
+ unsigned int type_offset;
+ unsigned int length, initial_length_size;
+ unsigned short version;
+ ULONGEST signature;
+ struct signatured_type *type_sig;
+ void **slot;
+ gdb_byte *ptr = info_ptr;
+
+ offset = ptr - dwarf2_per_objfile->types.buffer;
+
+ /* We need to read the type's signature in order to build the hash
+ table, but we don't need to read anything else just yet. */
+
+ /* Sanity check to ensure entire cu is present. */
+ length = read_initial_length (objfile->obfd, ptr, &initial_length_size);
+ if (ptr + length + initial_length_size
+ > dwarf2_per_objfile->types.buffer + dwarf2_per_objfile->types.size)
+ {
+ complaint (&symfile_complaints,
+ _("debug type entry runs off end of `.debug_types' section, ignored"));
+ break;
+ }
+
+ offset_size = initial_length_size == 4 ? 4 : 8;
+ ptr += initial_length_size;
+ version = bfd_get_16 (objfile->obfd, ptr);
+ ptr += 2;
+ ptr += offset_size; /* abbrev offset */
+ ptr += 1; /* address size */
+ signature = bfd_get_64 (objfile->obfd, ptr);
+ ptr += 8;
+ type_offset = read_offset_1 (objfile->obfd, ptr, offset_size);
+
+ type_sig = obstack_alloc (&objfile->objfile_obstack, sizeof (*type_sig));
+ memset (type_sig, 0, sizeof (*type_sig));
+ type_sig->signature = signature;
+ type_sig->offset = offset;
+ type_sig->type_offset = type_offset;
+
+ slot = htab_find_slot (types_htab, type_sig, INSERT);
+ gdb_assert (slot != NULL);
+ *slot = type_sig;
+
+ if (dwarf2_die_debug)
+ {
+ fprintf_unfiltered (gdb_stdlog, " offset 0x%x, signature 0x%s\n",
+ offset, phex (signature, sizeof (signature)));
+ }
+
+ info_ptr = info_ptr + initial_length_size + length;
+ }
+
+ dwarf2_per_objfile->signatured_types = types_htab;
+
+ return 1;
+}
+
+/* Lookup a signature based type.
+ Returns NULL if SIG is not present in the table. */
+
+static struct signatured_type *
+lookup_signatured_type (struct objfile *objfile, ULONGEST sig)
+{
+ struct signatured_type find_entry, *entry;
+
+ if (dwarf2_per_objfile->signatured_types == NULL)
+ {
+ complaint (&symfile_complaints,
+ _("missing `.debug_types' section for DW_FORM_sig8 die"));
+ return 0;
+ }
+
+ find_entry.signature = sig;
+ entry = htab_find (dwarf2_per_objfile->signatured_types, &find_entry);
+ return entry;
+}
+
+/* Subroutine of process_type_comp_unit and dwarf2_build_psymtabs_hard
+ to combine the common parts.
Process a compilation unit for a psymtab.
- BUFFER is a pointer to the beginning of the dwarf section buffer.
+ BUFFER is a pointer to the beginning of the dwarf section buffer,
+ either .debug_info or debug_types.
INFO_PTR is a pointer to the start of the CU.
Returns a pointer to the next CU. */
@@ -1653,11 +1858,19 @@ process_psymtab_comp_unit (struct objfil
make_cleanup (dwarf2_free_abbrev_table, &cu);
/* Read the compilation unit die. */
+ if (this_cu->from_debug_types)
+ info_ptr += 8 /*signature*/ + cu.header.offset_size;
abbrev = peek_die_abbrev (info_ptr, &bytes_read, &cu);
info_ptr = read_partial_die (&comp_unit_die, abbrev, bytes_read, abfd,
buffer, info_ptr, &cu);
- if (comp_unit_die.tag == DW_TAG_partial_unit)
+ if (this_cu->from_debug_types)
+ {
+ /* ??? How come this is for .debug_types only? */
+ this_cu->offset = cu.header.offset;
+ this_cu->length = cu.header.length + cu.header.initial_length_size;
+ }
+ else if (comp_unit_die.tag == DW_TAG_partial_unit)
{
info_ptr = (beg_of_comp_unit + cu.header.length
+ cu.header.initial_length_size);
@@ -1708,7 +1921,8 @@ process_psymtab_comp_unit (struct objfil
this_cu->psymtab = pst;
/* Possibly set the default values of LOWPC and HIGHPC from
- `DW_AT_ranges'. */
+ `DW_AT_ranges'.
+ ??? Is this valid for .debug_types? */
if (cu.has_ranges_offset)
{
if (dwarf2_ranges_read (cu.ranges_offset, &comp_unit_die.lowpc,
@@ -1764,12 +1978,18 @@ process_psymtab_comp_unit (struct objfil
/* If there is already a psymtab or symtab for a file of this
name, remove it. (If there is a symtab, more drastic things
also happen.) This happens in VxWorks. */
- free_named_symtabs (pst->filename);
+ if (! this_cu->from_debug_types)
+ free_named_symtabs (pst->filename);
info_ptr = (beg_of_comp_unit + cu.header.length
+ cu.header.initial_length_size);
- if (comp_unit_die.has_stmt_list)
+ if (this_cu->from_debug_types)
+ {
+ /* ??? It's not clear we want to do anything with stmt lists here.
+ Waiting to see what gcc ultimately does. */
+ }
+ else if (comp_unit_die.has_stmt_list)
{
/* Get the list of files included in the current compilation unit,
and build a psymtab for each of them. */
@@ -1781,6 +2001,40 @@ process_psymtab_comp_unit (struct objfil
return info_ptr;
}
+/* Traversal function for htab_traverse_noresize.
+ Process one .debug_types comp-unit. */
+
+static int
+process_type_comp_unit (void **slot, void *info)
+{
+ struct signatured_type *entry = (struct signatured_type *) *slot;
+ struct objfile *objfile = (struct objfile *) info;
+ struct dwarf2_per_cu_data *this_cu;
+
+ this_cu = &entry->per_cu;
+ this_cu->from_debug_types = 1;
+
+ process_psymtab_comp_unit (objfile, this_cu,
+ dwarf2_per_objfile->types.buffer,
+ dwarf2_per_objfile->types.buffer + entry->offset,
+ dwarf2_per_objfile->types.size);
+
+ return 1;
+}
+
+/* Subroutine of dwarf2_build_psymtabs_hard to simplify it.
+ Build partial symbol tables for the .debug_types comp-units. */
+
+static void
+build_type_psymtabs (struct objfile *objfile)
+{
+ if (! create_debug_types_hash_table (objfile))
+ return;
+
+ htab_traverse_noresize (dwarf2_per_objfile->signatured_types,
+ process_type_comp_unit, objfile);
+}
+
/* Build the partial symbol table by doing a quick pass through the
.debug_info and .debug_abbrev sections. */
@@ -1799,6 +2053,8 @@ dwarf2_build_psymtabs_hard (struct objfi
read_in_chain. Make sure to free them when we're done. */
back_to = make_cleanup (free_cached_comp_units, NULL);
+ build_type_psymtabs (objfile);
+
create_all_comp_units (objfile);
objfile->psymtabs_addrmap =
@@ -1852,6 +2108,8 @@ load_partial_comp_unit (struct dwarf2_pe
unsigned int bytes_read;
struct cleanup *back_to;
+ gdb_assert (! this_cu->from_debug_types);
+
info_ptr = dwarf2_per_objfile->info.buffer + this_cu->offset;
beg_of_comp_unit = info_ptr;
@@ -2592,6 +2850,7 @@ skip_one_die (gdb_byte *buffer, gdb_byte
break;
case DW_FORM_data8:
case DW_FORM_ref8:
+ case DW_FORM_sig8:
info_ptr += 8;
break;
case DW_FORM_string:
@@ -2727,12 +2986,6 @@ queue_comp_unit (struct dwarf2_per_cu_da
dwarf2_queue_tail->next = item;
dwarf2_queue_tail = item;
-
- /* Either PER_CU is the CU we want to process, or we're following a reference
- pointing into PER_CU. Either way, we need its DIEs now. */
- 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;
}
/* Process the queue. */
@@ -2827,6 +3080,11 @@ psymtab_to_symtab_1 (struct partial_symt
queue_comp_unit (per_cu, pst->objfile);
+ if (per_cu->from_debug_types)
+ read_signatured_type_at_offset (pst->objfile, per_cu->offset);
+ else
+ load_full_comp_unit (per_cu, pst->objfile);
+
process_queue (pst->objfile);
/* Age the cache, releasing compilation units that have not
@@ -2849,6 +3107,8 @@ load_full_comp_unit (struct dwarf2_per_c
struct attribute *attr;
CORE_ADDR baseaddr;
+ gdb_assert (! per_cu->from_debug_types);
+
/* Set local variables from the partial symbol table info. */
offset = per_cu->offset;
@@ -2888,6 +3148,10 @@ load_full_comp_unit (struct dwarf2_per_c
else
set_cu_language (language_minimal, cu);
+ /* Link this CU into read_in_chain. */
+ per_cu->cu->read_in_chain = dwarf2_per_objfile->read_in_chain;
+ dwarf2_per_objfile->read_in_chain = per_cu;
+
do_cleanups (back_to);
/* We've successfully allocated this compilation unit. Let our caller
@@ -2979,6 +3243,9 @@ process_die (struct die_info *die, struc
case DW_TAG_compile_unit:
read_file_scope (die, cu);
break;
+ case DW_TAG_type_unit:
+ read_type_unit_scope (die, cu);
+ break;
case DW_TAG_subprogram:
read_func_scope (die, cu);
break;
@@ -3222,6 +3489,91 @@ read_file_scope (struct die_info *die, s
do_cleanups (back_to);
}
+/* For TUs we want to skip the first top level sibling if it's not the
+ actual type being defined by this TU. In this case the first top
+ level sibling is there to provide context only. */
+
+static void
+read_type_unit_scope (struct die_info *die, struct dwarf2_cu *cu)
+{
+ struct objfile *objfile = cu->objfile;
+ struct cleanup *back_to = make_cleanup (null_cleanup, 0);
+ CORE_ADDR lowpc;
+ struct attribute *attr;
+ char *name = NULL;
+ char *comp_dir = NULL;
+ struct die_info *child_die;
+ bfd *abfd = objfile->obfd;
+ struct line_header *line_header = 0;
+
+ /* start_symtab needs a low pc, but we don't really have one.
+ Do what read_file_scope would do in the absence of such info. */
+ lowpc = ANOFFSET (objfile->section_offsets, SECT_OFF_TEXT (objfile));
+
+ /* Find the filename. Do not use dwarf2_name here, since the filename
+ is not a source language identifier. */
+ attr = dwarf2_attr (die, DW_AT_name, cu);
+ if (attr)
+ {
+ name = DW_STRING (attr);
+ }
+
+ attr = dwarf2_attr (die, DW_AT_comp_dir, cu);
+ if (attr)
+ {
+ comp_dir = DW_STRING (attr);
+ }
+ else if (name != NULL && IS_ABSOLUTE_PATH (name))
+ {
+ comp_dir = ldirname (name);
+ if (comp_dir != NULL)
+ make_cleanup (xfree, comp_dir);
+ }
+
+ if (name == NULL)
+ name = "<unknown>";
+
+ attr = dwarf2_attr (die, DW_AT_language, cu);
+ if (attr)
+ {
+ set_cu_language (DW_UNSND (attr), cu);
+ }
+
+ /* This isn't technically needed today. It is done for symmetry
+ with read_file_scope. */
+ attr = dwarf2_attr (die, DW_AT_producer, cu);
+ if (attr)
+ cu->producer = DW_STRING (attr);
+
+ /* We assume that we're processing GCC output. */
+ processing_gcc_compilation = 2;
+
+ processing_has_namespace_info = 0;
+
+ start_symtab (name, comp_dir, lowpc);
+ record_debugformat ("DWARF 2");
+ record_producer (cu->producer);
+
+ /* Process the dies in the type unit. */
+ if (die->child == NULL)
+ {
+ dump_die_for_error (die);
+ error (_("Dwarf Error: Missing children for type unit [in module %s]"),
+ bfd_get_filename (abfd));
+ }
+
+ child_die = die->child;
+
+ while (child_die && child_die->tag)
+ {
+ process_die (child_die, cu);
+
+ child_die = sibling_die (child_die);
+ }
+
+ do_cleanups (back_to);
+}
+
static void
add_to_cu_func_list (const char *name, CORE_ADDR lowpc, CORE_ADDR highpc,
struct dwarf2_cu *cu)
@@ -4414,6 +4766,22 @@ read_structure_type (struct die_info *di
if (type)
return type;
+ /* If the definition of this type lives in .debug_types, read that type.
+ Don't follow DW_AT_specification though, that will take us back up
+ the chain and we want to go down. */
+ attr = dwarf2_attr_no_follow (die, DW_AT_signature, cu);
+ if (attr)
+ {
+ struct dwarf2_cu *type_cu = cu;
+ struct die_info *type_die = follow_die_ref_or_sig (die, attr, &type_cu);
+ /* We could just recurse on read_structure_type, but we need to call
+ get_die_type to ensure only one type for this DIE is created.
+ This is important, for example, because for c++ classes we need
+ TYPE_NAME set which is only done by new_symbol. Blech. */
+ type = read_type_die (type_die, type_cu);
+ return set_die_type (die, type, cu);
+ }
+
type = alloc_type (objfile);
INIT_CPLUS_SPECIFIC (type);
@@ -4628,6 +4996,18 @@ read_enumeration_type (struct die_info *
struct attribute *attr;
const char *name;
+ /* If the definition of this type lives in .debug_types, read that type.
+ Don't follow DW_AT_specification though, that will take us back up
+ the chain and we want to go down. */
+ attr = dwarf2_attr_no_follow (die, DW_AT_signature, cu);
+ if (attr)
+ {
+ struct dwarf2_cu *type_cu = cu;
+ struct die_info *type_die = follow_die_ref_or_sig (die, attr, &type_cu);
+ type = read_type_die (type_die, type_cu);
+ return set_die_type (die, type, cu);
+ }
+
type = alloc_type (objfile);
TYPE_CODE (type) = TYPE_CODE_ENUM;
@@ -5549,7 +5929,10 @@ init_cu_die_reader (struct die_reader_sp
{
reader->abfd = cu->objfile->obfd;
reader->cu = cu;
- reader->buffer = dwarf2_per_objfile->info.buffer;
+ if (cu->per_cu->from_debug_types)
+ reader->buffer = dwarf2_per_objfile->types.buffer;
+ else
+ reader->buffer = dwarf2_per_objfile->info.buffer;
}
/* Read a whole compilation unit into a linked list of dies. */
@@ -5559,6 +5942,7 @@ read_comp_unit (gdb_byte *info_ptr, stru
{
struct die_reader_specs reader_specs;
+ gdb_assert (cu->die_hash == NULL);
cu->die_hash
= htab_create_alloc_ex (cu->header.length / 12,
die_hash,
@@ -5587,7 +5971,14 @@ read_die_and_children (const struct die_
if (dwarf2_die_debug)
{
- fprintf_unfiltered (gdb_stdlog, "Read die from .debug_info:\n");
+ fprintf_unfiltered (gdb_stdlog,
+ "\nRead die from %s of %s:\n",
+ reader->buffer == dwarf2_per_objfile->info.buffer
+ ? ".debug_info"
+ : reader->buffer == dwarf2_per_objfile->types.buffer
+ ? ".debug_types"
+ : "unknown section",
+ reader->abfd->filename);
dump_die (result, dwarf2_die_debug);
}
@@ -6157,6 +6548,7 @@ read_partial_die (struct partial_die_inf
switch (part_die->tag)
{
case DW_TAG_compile_unit:
+ case DW_TAG_type_unit:
/* Compilation units have a DW_AT_name that is a filename, not
a source language identifier. */
case DW_TAG_enumeration_type:
@@ -6319,7 +6711,10 @@ find_partial_die_in_comp_unit (unsigned
return lookup_die;
}
-/* Find a partial DIE at OFFSET, which may or may not be in CU. */
+/* Find a partial DIE at OFFSET, which may or may not be in CU,
+ except in the case of .debug_types DIEs which do not reference
+ outside their CU (they do however referencing other types via
+ DW_FORM_sig8). */
static struct partial_die_info *
find_partial_die (unsigned int offset, struct dwarf2_cu *cu)
@@ -6327,6 +6722,14 @@ find_partial_die (unsigned int offset, s
struct dwarf2_per_cu_data *per_cu = NULL;
struct partial_die_info *pd = NULL;
+ if (cu->per_cu->from_debug_types)
+ {
+ pd = find_partial_die_in_comp_unit (offset, cu);
+ if (pd != NULL)
+ return pd;
+ goto NotFound;
+ }
+
if (offset_in_cu_p (&cu->header, offset))
{
pd = find_partial_die_in_comp_unit (offset, cu);
@@ -6380,6 +6783,8 @@ find_partial_die (unsigned int offset, s
pd = find_partial_die_in_comp_unit (offset, per_cu->cu);
}
+ NotFound:
+
if (pd == NULL)
internal_error (__FILE__, __LINE__,
_("could not find partial DIE 0x%x in cache [from module %s]\n"),
@@ -6533,6 +6938,14 @@ read_attribute_value (struct attribute *
DW_ADDR (attr) = cu->header.offset + read_8_bytes (abfd, info_ptr);
info_ptr += 8;
break;
+ case DW_FORM_sig8:
+ /* Convert the signature to something we can record in DW_UNSND
+ for later lookup.
+ NOTE: This is NULL if the type wasn't found. */
+ DW_SIGNATURED_TYPE (attr) =
+ lookup_signatured_type (cu->objfile, read_8_bytes (abfd, info_ptr));
+ info_ptr += 8;
+ break;
case DW_FORM_ref_udata:
DW_ADDR (attr) = (cu->header.offset
+ read_unsigned_leb128 (abfd, info_ptr, &bytes_read));
@@ -6995,6 +7408,27 @@ dwarf2_attr (struct die_info *die, unsig
return NULL;
}
+/* Return the named attribute or NULL if not there,
+ but do not follow DW_AT_specification, etc.
+ This is for use in contexts where we're reading .debug_types dies.
+ Following DW_AT_specification, DW_AT_abstract_origin will take us
+ back up the chain, and we want to go down. */
+
+static struct attribute *
+dwarf2_attr_no_follow (struct die_info *die, unsigned int name,
+ struct dwarf2_cu *cu)
+{
+ unsigned int i;
+
+ for (i = 0; i < die->num_attrs; ++i)
+ {
+ if (die->attrs[i].name == name)
+ return &die->attrs[i];
+ }
+
+ return NULL;
+}
+
/* Return non-zero iff the attribute NAME is defined for the given DIE,
and holds a non-zero value. This function should only be used for
DW_FORM_flag attributes. */
@@ -8125,8 +8559,8 @@ die_type (struct die_info *die, struct d
/* A missing DW_AT_type represents a void type. */
return builtin_type (gdbarch)->builtin_void;
}
- else
- type_die = follow_die_ref (die, type_attr, &cu);
+
+ type_die = follow_die_ref_or_sig (die, type_attr, &cu);
type = tag_type_to_type (type_die, cu);
if (!type)
@@ -8151,7 +8585,7 @@ die_containing_type (struct die_info *di
type_attr = dwarf2_attr (die, DW_AT_containing_type, cu);
if (type_attr)
{
- type_die = follow_die_ref (die, type_attr, &cu);
+ type_die = follow_die_ref_or_sig (die, type_attr, &cu);
type = tag_type_to_type (type_die, cu);
}
if (!type)
@@ -8589,6 +9023,8 @@ dwarf_tag_name (unsigned tag)
return "DW_TAG_condition";
case DW_TAG_shared_type:
return "DW_TAG_shared_type";
+ case DW_TAG_type_unit:
+ return "DW_TAG_type_unit";
case DW_TAG_MIPS_loop:
return "DW_TAG_MIPS_loop";
case DW_TAG_HP_array_descriptor:
@@ -8804,6 +9240,9 @@ dwarf_attr_name (unsigned attr)
return "DW_AT_pure";
case DW_AT_recursive:
return "DW_AT_recursive";
+ /* DWARF 4 values. */
+ case DW_AT_signature:
+ return "DW_AT_signature";
/* SGI/MIPS extensions. */
#ifdef MIPS /* collides with DW_AT_HP_block_index */
case DW_AT_MIPS_fde:
@@ -8875,6 +9314,8 @@ dwarf_attr_name (unsigned attr)
return "DW_AT_body_end";
case DW_AT_GNU_vector:
return "DW_AT_GNU_vector";
+ case DW_AT_GNU_odr_signature:
+ return "DW_AT_GNU_odr_signature";
/* VMS extensions. */
case DW_AT_VMS_rtnbeg_pd_address:
return "DW_AT_VMS_rtnbeg_pd_address";
@@ -8942,6 +9383,14 @@ dwarf_form_name (unsigned form)
return "DW_FORM_ref_udata";
case DW_FORM_indirect:
return "DW_FORM_indirect";
+ case DW_FORM_sec_offset:
+ return "DW_FORM_sec_offset";
+ case DW_FORM_exprloc:
+ return "DW_FORM_exprloc";
+ case DW_FORM_flag_present:
+ return "DW_FORM_flag_present";
+ case DW_FORM_sig8:
+ return "DW_FORM_sig8";
case GDB_FORM_cached_string:
return "GDB_FORM_cached_string";
default:
@@ -9487,6 +9936,13 @@ dump_die_shallow (struct ui_file *f, int
case DW_FORM_sdata:
fprintf_unfiltered (f, "constant: %ld", DW_UNSND (&die->attrs[i]));
break;
+ case DW_FORM_sig8:
+ if (DW_SIGNATURED_TYPE (&die->attrs[i]) != NULL)
+ fprintf_unfiltered (f, "signatured type, offset: 0x%x",
+ DW_SIGNATURED_TYPE (&die->attrs[i])->offset);
+ else
+ fprintf_unfiltered (f, "signatured type, offset: unknown");
+ break;
case DW_FORM_string:
case DW_FORM_strp:
case GDB_FORM_cached_string:
@@ -9624,9 +10080,11 @@ dwarf2_get_attr_constant_value (struct a
}
/* THIS_CU has a reference to PER_CU. If necessary, load the new compilation
- unit and add it to our queue. */
+ unit and add it to our queue.
+ The result is non-zero if PER_CU was queued, otherwise the result is zero
+ meaning either PER_CU is already queued or it is already loaded. */
-static void
+static int
maybe_queue_comp_unit (struct dwarf2_cu *this_cu,
struct dwarf2_per_cu_data *per_cu)
{
@@ -9636,18 +10094,48 @@ maybe_queue_comp_unit (struct dwarf2_cu
/* If it's already on the queue, we have nothing to do. */
if (per_cu->queued)
- return;
+ return 0;
/* If the compilation unit is already loaded, just mark it as
used. */
if (per_cu->cu != NULL)
{
per_cu->cu->last_used = 0;
- return;
+ return 0;
}
/* Add it to the queue. */
queue_comp_unit (per_cu, this_cu->objfile);
+
+ return 1;
+}
+
+/* Follow reference or signature attribute ATTR of SRC_DIE.
+ On entry *REF_CU is the CU of SRC_DIE.
+ On exit *REF_CU is the CU of the result. */
+
+static struct die_info *
+follow_die_ref_or_sig (struct die_info *src_die, struct attribute *attr,
+ struct dwarf2_cu **ref_cu)
+{
+ struct die_info *die;
+
+ if (is_ref_attr (attr))
+ {
+ die = follow_die_ref (src_die, attr, ref_cu);
+ }
+ else if (attr->form == DW_FORM_sig8)
+ {
+ die = follow_die_sig (src_die, attr, ref_cu);
+ }
+ else
+ {
+ dump_die_for_error (src_die);
+ error (_("Dwarf Error: Expected reference attribute [in module %s]"),
+ (*ref_cu)->objfile->name);
+ }
+
+ return die;
}
/* Follow reference attribute ATTR of SRC_DIE.
@@ -9663,15 +10151,27 @@ follow_die_ref (struct die_info *src_die
struct die_info temp_die;
struct dwarf2_cu *target_cu, *cu = *ref_cu;
+ gdb_assert (cu->per_cu != NULL);
+
offset = dwarf2_get_ref_die_offset (attr);
- if (! offset_in_cu_p (&cu->header, offset))
+ if (cu->per_cu->from_debug_types)
+ {
+ /* .debug_types CUs cannot reference anything outside their CU.
+ If they need to, they have to reference a signatured type via
+ DW_FORM_sig8. */
+ if (! offset_in_cu_p (&cu->header, offset))
+ goto NotFound;
+ target_cu = cu;
+ }
+ else if (! offset_in_cu_p (&cu->header, offset))
{
struct dwarf2_per_cu_data *per_cu;
per_cu = dwarf2_find_containing_comp_unit (offset, cu->objfile);
/* If necessary, add it to the queue and load its DIEs. */
- maybe_queue_comp_unit (cu, per_cu);
+ if (maybe_queue_comp_unit (cu, per_cu))
+ load_full_comp_unit (per_cu, cu->objfile);
target_cu = per_cu->cu;
}
@@ -9684,9 +10184,164 @@ follow_die_ref (struct die_info *src_die
if (die)
return die;
- error (_("Dwarf Error: Cannot find DIE at 0x%lx referenced from DIE "
- "at 0x%lx [in module %s]"),
- (long) offset, (long) src_die->offset, cu->objfile->name);
+ NotFound:
+
+ error (_("Dwarf Error: Cannot find DIE at 0x%x referenced from DIE "
+ "at 0x%x [in module %s]"),
+ offset, src_die->offset, cu->objfile->name);
+}
+
+/* Follow the signature attribute ATTR in SRC_DIE.
+ On entry *REF_CU is the CU of SRC_DIE.
+ On exit *REF_CU is the CU of the result. */
+
+static struct die_info *
+follow_die_sig (struct die_info *src_die, struct attribute *attr,
+ struct dwarf2_cu **ref_cu)
+{
+ struct objfile *objfile = (*ref_cu)->objfile;
+ struct die_info temp_die;
+ struct signatured_type *sig_type = DW_SIGNATURED_TYPE (attr);
+ struct dwarf2_cu *sig_cu;
+ struct die_info *die;
+
+ /* sig_type will be NULL if the signatured type is missing from
+ the debug info. */
+ if (sig_type == NULL)
+ error (_("Dwarf Error: Cannot find signatured DIE referenced from DIE "
+ "at 0x%x [in module %s]"),
+ src_die->offset, objfile->name);
+
+ /* If necessary, add it to the queue and load its DIEs. */
+
+ if (maybe_queue_comp_unit (*ref_cu, &sig_type->per_cu))
+ read_signatured_type (objfile, sig_type);
+
+ gdb_assert (sig_type->per_cu.cu != NULL);
+
+ sig_cu = sig_type->per_cu.cu;
+ temp_die.offset = sig_cu->header.offset + sig_type->type_offset;
+ die = htab_find_with_hash (sig_cu->die_hash, &temp_die, temp_die.offset);
+ if (die)
+ {
+ *ref_cu = sig_cu;
+ return die;
+ }
+
+ error (_("Dwarf Error: Cannot find signatured DIE at 0x%x referenced from DIE "
+ "at 0x%x [in module %s]"),
+ sig_type->type_offset, src_die->offset, objfile->name);
+}
+
+/* Given an offset of a signatured type, return its signatured_type. */
+
+static struct signatured_type *
+lookup_signatured_type_at_offset (struct objfile *objfile, unsigned int offset)
+{
+ gdb_byte *info_ptr = dwarf2_per_objfile->types.buffer + offset;
+ unsigned int length, initial_length_size;
+ unsigned int sig_offset;
+ struct signatured_type find_entry, *type_sig;
+
+ length = read_initial_length (objfile->obfd, info_ptr, &initial_length_size);
+ sig_offset = (initial_length_size
+ + 2 /*version*/
+ + (initial_length_size == 4 ? 4 : 8) /*debug_abbrev_offset*/
+ + 1 /*address_size*/);
+ find_entry.signature = bfd_get_64 (objfile->obfd, info_ptr + sig_offset);
+ type_sig = htab_find (dwarf2_per_objfile->signatured_types, &find_entry);
+
+ /* This is only used to lookup previously recorded types.
+ If we didn't find it, it's our bug. */
+ gdb_assert (type_sig != NULL);
+ gdb_assert (offset == type_sig->offset);
+
+ return type_sig;
+}
+
+/* Read in signatured type at OFFSET and build its CU and die(s). */
+
+static void
+read_signatured_type_at_offset (struct objfile *objfile,
+ unsigned int offset)
+{
+ struct signatured_type *type_sig;
+
+ /* We have the section offset, but we need the signature to do the
+ hash table lookup. */
+ type_sig = lookup_signatured_type_at_offset (objfile, offset);
+
+ gdb_assert (type_sig->per_cu.cu == NULL);
+
+ read_signatured_type (objfile, type_sig);
+
+ gdb_assert (type_sig->per_cu.cu != NULL);
+}
+
+/* Read in a signatured type and build its CU and DIEs. */
+
+static void
+read_signatured_type (struct objfile *objfile,
+ struct signatured_type *type_sig)
+{
+ gdb_byte *types_ptr = dwarf2_per_objfile->types.buffer + type_sig->offset;
+ struct die_reader_specs reader_specs;
+ struct dwarf2_cu *cu;
+ ULONGEST signature;
+ struct cleanup *back_to, *free_cu_cleanup;
+ struct attribute *attr;
+
+ gdb_assert (type_sig->per_cu.cu == NULL);
+
+ cu = xmalloc (sizeof (struct dwarf2_cu));
+ memset (cu, 0, sizeof (struct dwarf2_cu));
+ obstack_init (&cu->comp_unit_obstack);
+ cu->objfile = objfile;
+ type_sig->per_cu.cu = cu;
+ cu->per_cu = &type_sig->per_cu;
+
+ /* If an error occurs while loading, release our storage. */
+ free_cu_cleanup = make_cleanup (free_one_comp_unit, cu);
+
+ types_ptr = read_type_comp_unit_head (&cu->header, &signature,
+ types_ptr, objfile->obfd);
+ gdb_assert (signature == type_sig->signature);
+
+ cu->die_hash
+ = htab_create_alloc_ex (cu->header.length / 12,
+ die_hash,
+ die_eq,
+ NULL,
+ &cu->comp_unit_obstack,
+ hashtab_obstack_allocate,
+ dummy_obstack_deallocate);
+
+ dwarf2_read_abbrevs (cu->objfile->obfd, cu);
+ back_to = make_cleanup (dwarf2_free_abbrev_table, cu);
+
+ init_cu_die_reader (&reader_specs, cu);
+
+ cu->dies = read_die_and_children (&reader_specs, types_ptr, &types_ptr,
+ NULL /*parent*/);
+
+ /* We try not to read any attributes in this function, because not
+ all objfiles needed for references have been loaded yet, and symbol
+ table processing isn't initialized. But we have to set the CU language,
+ or we won't be able to build types correctly. */
+ attr = dwarf2_attr (cu->dies, DW_AT_language, cu);
+ if (attr)
+ set_cu_language (DW_UNSND (attr), cu);
+ else
+ set_cu_language (language_minimal, cu);
+
+ do_cleanups (back_to);
+
+ /* We've successfully allocated this compilation unit. Let our caller
+ clean it up when finished with it. */
+ discard_cleanups (free_cu_cleanup);
+
+ type_sig->per_cu.cu->read_in_chain = dwarf2_per_objfile->read_in_chain;
+ dwarf2_per_objfile->read_in_chain = &type_sig->per_cu;
}
/* Decode simple location descriptions.
@@ -10622,8 +11277,8 @@ dwarf2_per_cu_addr_size (struct dwarf2_p
}
}
-/* Locate the compilation unit from CU's objfile which contains the
- DIE at OFFSET. Raises an error on failure. */
+/* Locate the .debug_info compilation unit from CU's objfile which contains
+ the DIE at OFFSET. Raises an error on failure. */
static struct dwarf2_per_cu_data *
dwarf2_find_containing_comp_unit (unsigned int offset,