[rfa/dwarf] Support for attributes pointing to a different CU
Daniel Jacobowitz
drow@false.org
Mon Oct 4 23:35:00 GMT 2004
On Mon, Oct 04, 2004 at 05:08:36PM -0500, Jim Blandy wrote:
>
> This patch still avoids building the all_comp_units table if it never
> finds a CU whose abbrev table suggests it might contain inter-CU
> references. What I was actually suggesting was building
> all_comp_units for every objfile, unconditionally --- even for
> objfiles with no inter-CU references, and which will thus never use
> the table.
>
> The win would be to remove the case of an absent all_comp_units table
> from the code. I want to keep the number of different cases one needs
> to think about down where doing so doesn't provide a noticeable
> performance hit.
>
> On an 8000-CU objfile (what you estimated glibc compiled with
> duplicate elimination would have), that would be a memory overhead of
> 160k, which doesn't seem bad. It's true that that would be a separate
> pass over the .debug_info section, but the latest patch will do two
> passes anyway.
I don't think it will do two passes... but:
> The quadratic bit in create_all_comp_units to recover the psymtabs
> we'd already created wouldn't be needed any more.
True.
The performance impact is negligibly in favor of lazy allocation on an
inter-CU object, about 1% in favor of it on an old object, and about 1%
against it (!!!) on an old object but reading in full symbols.
Apparently:
- it's a wash, so we may as well use inter-cu-aware mode always
- I ought to get around to cleaning up the releasing of full DIEs;
that's why it's faster, I think, because the last five compilation
units (in the cache) don't get freed. This could be obstacked
easily enough.
Here's a revision which always creates the CU tree. Retested on
i686-pc-linux-gnu; no changes.
--
Daniel Jacobowitz
2004-10-04 Daniel Jacobowitz <dan@debian.org>
* dwarf2read.c (REF_HASH_SIZE): Move earlier.
(die_ref_table): Remove.
(struct dwarf2_cu): Add DIES, DEPENDENCIES, and DIE_REF_TABLE.
(struct dwarf2_per_cu_data): Add PSYMTAB. Add a comment describing
the usage of this type.
(struct dwarf2_per_objfile): Update comment for ALL_COMP_UNITS.
(struct dwarf2_pinfo, PST_PRIVATE, DWARF_INFO_OFFSET): Remove.
(struct dwarf2_queue_item, dwarf2_queue, dwarf2_queue_tail): New.
(dwarf2_create_include_psymtab): Update comment.
(find_partial_die): Remove third argument. Remove unreachable call
to error ().
(dwarf2_find_containing_comp_unit): Update comments. Change one
assertion to an error. Remove an unreachable error.
(dwarf2_find_comp_unit): Update comments.
(type_at_offset): Remove dead code.
(make_cleanup_free_die_list, dwarf2_empty_hash_tables): Remove.
(store_in_ref_table): Add CU argument.
(follow_die_ref): Take DIE, attribute, and CU arguments. Handle
inter-compilation-unit references.
(load_full_comp_unit, process_full_comp_unit): New functions, based
on psymtab_to_symtab_1.
(psymtab_to_symtab_1): Use them.
(dwarf2_add_dependence): New function.
(dwarf2_build_psymtabs_hard): Set the psymtab in per_cu. Always create
a per_cu structure, and save it in READ_PSYMTAB_PRIVATE.
(partial_die_parent_scope, guess_structure_name): Update for changes
to find_partial_die.
(dwarf2_psymtab_to_symtab): Initialize dwarf2_per_objfile here.
(queue_comp_unit, process_queue, dwarf2_release_queue): New.
(read_comp_unit): Don't call dwarf2_empty_hash_tables.
(read_die_and_children): Update call to store_in_ref_table.
(do_free_die_list_cleanup): Remove.
(fixup_partial_die): Update for changes to find_partial_die.
(read_full_die): Handle queueing absolute references.
(read_attribute_value): Use DW_ADDR for all DW_FORM_ref* forms.
(dwarf2_attr, die_specification, die_type)
(die_containing_type, dwarf2_extension): Update calls to
follow_die_ref.
(dump_die): Update DW_FORM_ref* handling.
(dwarf2_get_ref_die_offset): Likewise.
(free_one_comp_unit): Release the dies list.
(dwarf2_mark_helper): New function.
(dwarf2_mark): Use it.
--- src/gdb/dwarf2read.c 2004-10-03 12:14:10.000000000 -0400
+++ src/gdb/dwarf2read.c 2004-10-04 18:58:48.000000000 -0400
@@ -169,9 +169,8 @@ struct dwarf2_per_objfile
char *ranges_buffer;
char *loc_buffer;
- /* A list of all the compilation units. This will be set if and
- only if we have encountered a compilation unit with inter-CU
- references. */
+ /* A list of all the compilation units. This is used to locate
+ the target compilation unit of a particular reference. */
struct dwarf2_per_cu_data **all_comp_units;
/* The number of compilation units in ALL_COMP_UNITS. */
@@ -258,6 +257,11 @@ struct comp_unit_head
int base_known;
};
+/* Fixed size for the DIE hash table. */
+#ifndef REF_HASH_SIZE
+#define REF_HASH_SIZE 1021
+#endif
+
/* Internal state when decoding a particular compilation unit. */
struct dwarf2_cu
{
@@ -325,6 +329,17 @@ struct dwarf2_cu
/* How many compilation units ago was this CU last referenced? */
int last_used;
+ /* A hash table of die offsets for following references. */
+ struct die_info *die_ref_table[REF_HASH_SIZE];
+
+ /* Full DIEs if read in. */
+ struct die_info *dies;
+
+ /* A set of pointers to dwarf2_per_cu_data objects for compilation
+ units referenced by this one. Only set during full symbol processing;
+ partial symbol tables do not have dependencies. */
+ htab_t dependencies;
+
/* Mark used when releasing cached dies. */
unsigned int mark : 1;
@@ -339,6 +354,12 @@ struct dwarf2_cu
unsigned int has_namespace_info : 1;
};
+/* Persistent data held for a compilation unit, even when not
+ processing it. We put a pointer to this structure in the
+ read_symtab_private field of the psymtab. If we encounter
+ inter-compilation-unit references, we also maintain a sorted
+ list of all compilation units. */
+
struct dwarf2_per_cu_data
{
/* The start offset and length of this compilation unit. 2**31-1
@@ -358,8 +379,10 @@ struct dwarf2_per_cu_data
holds a map of DIE offsets to types. It isn't always possible
to reconstruct this information later, so we have to preserve
it. */
-
htab_t type_hash;
+
+ /* The partial symbol table associated with this compilation unit. */
+ struct partial_symtab *psymtab;
};
/* The line number information for a compilation unit (found in the
@@ -551,13 +574,6 @@ struct dwarf_block
#define ATTR_ALLOC_CHUNK 4
#endif
-/* A hash table of die offsets for following references. */
-#ifndef REF_HASH_SIZE
-#define REF_HASH_SIZE 1021
-#endif
-
-static struct die_info *die_ref_table[REF_HASH_SIZE];
-
/* Allocate fields for structs, unions and enums in this size. */
#ifndef DW_FIELD_ALLOC_CHUNK
#define DW_FIELD_ALLOC_CHUNK 4
@@ -575,19 +591,6 @@ static int isreg; /* Object lives in re
decode_locdesc's return value is
the register number. */
-/* We put a pointer to this structure in the read_symtab_private field
- of the psymtab. */
-
-struct dwarf2_pinfo
- {
- /* Offset in .debug_info for this compilation unit. */
-
- unsigned long dwarf_info_offset;
- };
-
-#define PST_PRIVATE(p) ((struct dwarf2_pinfo *)(p)->read_symtab_private)
-#define DWARF_INFO_OFFSET(p) (PST_PRIVATE(p)->dwarf_info_offset)
-
/* FIXME: We might want to set this from BFD via bfd_arch_bits_per_byte,
but this would require a corresponding change in unpack_field_as_long
and friends. */
@@ -641,6 +644,17 @@ struct field_info
int nfnfields;
};
+/* One item on the queue of compilation units to read in full symbols
+ for. */
+struct dwarf2_queue_item
+{
+ struct dwarf2_per_cu_data *per_cu;
+ struct dwarf2_queue_item *next;
+};
+
+/* The current queue. */
+static struct dwarf2_queue_item *dwarf2_queue, *dwarf2_queue_tail;
+
/* Loaded secondary compilation units are kept in memory until they
have not been referenced for the processing of this many
compilation units. Set this to zero to disable caching. Cache
@@ -755,8 +769,7 @@ static char *read_partial_die (struct pa
bfd *, char *, struct dwarf2_cu *);
static struct partial_die_info *find_partial_die (unsigned long,
- struct dwarf2_cu *,
- struct dwarf2_cu **);
+ struct dwarf2_cu *);
static void fixup_partial_die (struct partial_die_info *,
struct dwarf2_cu *);
@@ -844,10 +857,6 @@ static struct type *die_type (struct die
static struct type *die_containing_type (struct die_info *,
struct dwarf2_cu *);
-#if 0
-static struct type *type_at_offset (unsigned int, struct objfile *);
-#endif
-
static struct type *tag_type_to_type (struct die_info *, struct dwarf2_cu *);
static void read_type_die (struct die_info *, struct dwarf2_cu *);
@@ -944,8 +953,6 @@ static struct die_info *read_die_and_sib
static void free_die_list (struct die_info *);
-static struct cleanup *make_cleanup_free_die_list (struct die_info *);
-
static void process_die (struct die_info *, struct dwarf2_cu *);
static char *dwarf2_linkage_name (struct die_info *, struct dwarf2_cu *);
@@ -979,16 +986,17 @@ static void dump_die (struct die_info *)
static void dump_die_list (struct die_info *);
-static void store_in_ref_table (unsigned int, struct die_info *);
-
-static void dwarf2_empty_hash_tables (void);
+static void store_in_ref_table (unsigned int, struct die_info *,
+ struct dwarf2_cu *);
static unsigned int dwarf2_get_ref_die_offset (struct attribute *,
struct dwarf2_cu *);
static int dwarf2_get_attr_constant_value (struct attribute *, int);
-static struct die_info *follow_die_ref (unsigned int);
+static struct die_info *follow_die_ref (struct die_info *,
+ struct attribute *,
+ struct dwarf2_cu *);
static struct type *dwarf2_fundamental_type (struct objfile *, int,
struct dwarf2_cu *);
@@ -1045,13 +1053,18 @@ static void free_one_cached_comp_unit (v
static void set_die_type (struct die_info *, struct type *,
struct dwarf2_cu *);
-#if 0
static void reset_die_and_siblings_types (struct die_info *,
struct dwarf2_cu *);
-#endif
static void create_all_comp_units (struct objfile *);
+static struct dwarf2_cu *load_full_comp_unit (struct dwarf2_per_cu_data *);
+
+static void process_full_comp_unit (struct dwarf2_per_cu_data *);
+
+static void dwarf2_add_dependence (struct dwarf2_cu *,
+ struct dwarf2_per_cu_data *);
+
static void dwarf2_mark (struct dwarf2_cu *);
static void dwarf2_clear_marks (struct dwarf2_per_cu_data *);
@@ -1336,9 +1349,7 @@ dwarf2_create_include_psymtab (char *nam
/* No private part is necessary for include psymtabs. This property
can be used to differentiate between such include psymtabs and
- the regular ones. If it ever happens that a regular psymtab can
- legitimally have a NULL private part, then we'll have to add a
- dedicated field for that in the dwarf2_pinfo structure. */
+ the regular ones. */
subpst->read_symtab_private = NULL;
}
@@ -1391,6 +1402,8 @@ 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);
+ create_all_comp_units (objfile);
+
/* Since the objects we're extracting from .debug_info vary in
length, only the individual functions to extract them (like
read_comp_unit_head and load_partial_die) can really know whether
@@ -1435,8 +1448,7 @@ dwarf2_build_psymtabs_hard (struct objfi
dwarf2_read_abbrevs (abfd, &cu);
make_cleanup (dwarf2_free_abbrev_table, &cu);
- if (cu.has_form_ref_addr && dwarf2_per_objfile->all_comp_units == NULL)
- create_all_comp_units (objfile);
+ this_cu = dwarf2_find_comp_unit (cu.header.offset, objfile);
/* Read the compilation unit die */
abbrev = peek_die_abbrev (info_ptr, &bytes_read, &cu);
@@ -1456,39 +1468,31 @@ dwarf2_build_psymtabs_hard (struct objfi
if (comp_unit_die.dirname)
pst->dirname = xstrdup (comp_unit_die.dirname);
- pst->read_symtab_private = (char *)
- obstack_alloc (&objfile->objfile_obstack, sizeof (struct dwarf2_pinfo));
- DWARF_INFO_OFFSET (pst) = beg_of_comp_unit - dwarf2_per_objfile->info_buffer;
+ pst->read_symtab_private = (char *) this_cu;
+
baseaddr = ANOFFSET (objfile->section_offsets, SECT_OFF_TEXT (objfile));
/* Store the function that reads in the rest of the symbol table */
pst->read_symtab = dwarf2_psymtab_to_symtab;
- if (dwarf2_per_objfile->all_comp_units != NULL)
- {
- struct dwarf2_per_cu_data *per_cu;
-
- per_cu = dwarf2_find_comp_unit (cu.header.offset, objfile);
-
- /* If this compilation unit was already read in, free the
- cached copy in order to read it in again. This is
- necessary because we skipped some symbols when we first
- read in the compilation unit (see load_partial_dies).
- This problem could be avoided, but the benefit is
- unclear. */
- if (per_cu->cu != NULL)
- free_one_cached_comp_unit (per_cu->cu);
-
- cu.per_cu = per_cu;
+ /* If this compilation unit was already read in, free the
+ cached copy in order to read it in again. This is
+ necessary because we skipped some symbols when we first
+ read in the compilation unit (see load_partial_dies).
+ This problem could be avoided, but the benefit is
+ unclear. */
+ if (this_cu->cu != NULL)
+ free_one_cached_comp_unit (this_cu->cu);
+
+ cu.per_cu = this_cu;
+
+ /* Note that this is a pointer to our stack frame, being
+ added to a global data structure. It will be cleaned up
+ in free_stack_comp_unit when we finish with this
+ compilation unit. */
+ this_cu->cu = &cu;
- /* Note that this is a pointer to our stack frame, being
- added to a global data structure. It will be cleaned up
- in free_stack_comp_unit when we finish with this
- compilation unit. */
- per_cu->cu = &cu;
- }
- else
- cu.per_cu = NULL;
+ this_cu->psymtab = pst;
/* Check if comp unit has_children.
If so, read the rest of the partial symbols from this comp unit.
@@ -1778,15 +1782,13 @@ partial_die_parent_scope (struct partial
{
char *grandparent_scope;
struct partial_die_info *parent, *real_pdi;
- struct dwarf2_cu *spec_cu;
/* We need to look at our parent DIE; if we have a DW_AT_specification,
then this means the parent of the specification DIE. */
real_pdi = pdi;
- spec_cu = cu;
while (real_pdi->has_specification)
- real_pdi = find_partial_die (real_pdi->spec_offset, spec_cu, &spec_cu);
+ real_pdi = find_partial_die (real_pdi->spec_offset, cu);
parent = real_pdi->die_parent;
if (parent == NULL)
@@ -1797,7 +1799,7 @@ partial_die_parent_scope (struct partial
fixup_partial_die (parent, cu);
- grandparent_scope = partial_die_parent_scope (parent, spec_cu);
+ grandparent_scope = partial_die_parent_scope (parent, cu);
if (parent->tag == DW_TAG_namespace
|| parent->tag == DW_TAG_structure_type
@@ -2071,16 +2073,14 @@ guess_structure_name (struct partial_die
struct partial_die_info *child_pdi = struct_pdi->die_child;
struct partial_die_info *real_pdi;
- struct dwarf2_cu *spec_cu;
/* If this DIE (this DIE's specification, if any) has a parent, then
we should not do this. We'll prepend the parent's fully qualified
name when we create the partial symbol. */
real_pdi = struct_pdi;
- spec_cu = cu;
while (real_pdi->has_specification)
- real_pdi = find_partial_die (real_pdi->spec_offset, spec_cu, &spec_cu);
+ real_pdi = find_partial_die (real_pdi->spec_offset, cu);
if (real_pdi->die_parent != NULL)
return;
@@ -2321,6 +2321,10 @@ dwarf2_psymtab_to_symtab (struct partial
gdb_flush (gdb_stdout);
}
+ /* Restore our global data. */
+ dwarf2_per_objfile = objfile_data (pst->objfile,
+ dwarf2_objfile_data_key);
+
psymtab_to_symtab_1 (pst);
/* Finish up the debug error message. */
@@ -2330,21 +2334,104 @@ dwarf2_psymtab_to_symtab (struct partial
}
}
+/* Add PER_CU to the queue. */
+
+static void
+queue_comp_unit (struct dwarf2_per_cu_data *per_cu)
+{
+ struct dwarf2_queue_item *item;
+
+ per_cu->queued = 1;
+ item = xmalloc (sizeof (*item));
+ item->per_cu = per_cu;
+ item->next = NULL;
+
+ if (dwarf2_queue == NULL)
+ dwarf2_queue = item;
+ else
+ dwarf2_queue_tail->next = item;
+
+ dwarf2_queue_tail = item;
+}
+
+/* Process the queue. */
+
+static void
+process_queue (struct objfile *objfile)
+{
+ struct dwarf2_queue_item *item, *next_item;
+
+ /* Initially, there is just one item on the queue. Load its DIEs,
+ and the DIEs of any other compilation units it requires,
+ transitively. */
+
+ for (item = dwarf2_queue; item != NULL; item = item->next)
+ {
+ /* Read in this compilation unit. This may add new items to
+ the end of the queue. */
+ load_full_comp_unit (item->per_cu);
+
+ 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)
+ reset_die_and_siblings_types (item->per_cu->cu->dies,
+ item->per_cu->cu);
+ }
+
+ /* Now everything left on the queue needs to be read in. Process
+ 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)
+ process_full_comp_unit (item->per_cu);
+
+ item->per_cu->queued = 0;
+ next_item = item->next;
+ xfree (item);
+ }
+
+ dwarf2_queue_tail = NULL;
+}
+
+/* Free all allocated queue entries. This function only releases anything if
+ an error was thrown; if the queue was processed then it would have been
+ freed as we went along. */
+
+static void
+dwarf2_release_queue (void *dummy)
+{
+ struct dwarf2_queue_item *item, *last;
+
+ item = dwarf2_queue;
+ while (item)
+ {
+ /* Anything still marked queued is likely to be in an
+ inconsistent state, so discard it. */
+ if (item->per_cu->queued)
+ {
+ if (item->per_cu->cu != NULL)
+ free_one_cached_comp_unit (item->per_cu->cu);
+ item->per_cu->queued = 0;
+ }
+
+ last = item;
+ item = item->next;
+ xfree (last);
+ }
+
+ dwarf2_queue = dwarf2_queue_tail = NULL;
+}
+
+/* Read in full symbols for PST, and anything it depends on. */
+
static void
psymtab_to_symtab_1 (struct partial_symtab *pst)
{
- struct objfile *objfile = pst->objfile;
- bfd *abfd = objfile->obfd;
- struct dwarf2_cu cu;
- struct die_info *dies;
- unsigned long offset;
- CORE_ADDR lowpc, highpc;
- struct die_info *child_die;
- char *info_ptr;
- struct symtab *symtab;
+ struct dwarf2_per_cu_data *per_cu;
struct cleanup *back_to;
- struct attribute *attr;
- CORE_ADDR baseaddr;
int i;
for (i = 0; i < pst->number_of_dependencies; i++)
@@ -2364,7 +2451,9 @@ psymtab_to_symtab_1 (struct partial_symt
psymtab_to_symtab_1 (pst->dependencies[i]);
}
- if (pst->read_symtab_private == NULL)
+ per_cu = (struct dwarf2_per_cu_data *) pst->read_symtab_private;
+
+ if (per_cu == NULL)
{
/* It's an include file, no symbols to read for it.
Everything is in the parent symtab. */
@@ -2372,40 +2461,107 @@ psymtab_to_symtab_1 (struct partial_symt
return;
}
- dwarf2_per_objfile = objfile_data (pst->objfile, dwarf2_objfile_data_key);
+ back_to = make_cleanup (dwarf2_release_queue, NULL);
+
+ queue_comp_unit (per_cu);
+
+ process_queue (pst->objfile);
+
+ /* Age the cache, releasing compilation units that have not
+ been used recently. */
+ age_cached_comp_units ();
+
+ do_cleanups (back_to);
+}
+
+/* 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)
+{
+ struct partial_symtab *pst = per_cu->psymtab;
+ bfd *abfd = pst->objfile->obfd;
+ struct dwarf2_cu *cu;
+ unsigned long offset;
+ char *info_ptr;
+ struct cleanup *back_to, *free_cu_cleanup;
+ struct attribute *attr;
+ CORE_ADDR baseaddr;
/* Set local variables from the partial symbol table info. */
- offset = DWARF_INFO_OFFSET (pst);
+ offset = per_cu->offset;
info_ptr = dwarf2_per_objfile->info_buffer + offset;
- baseaddr = ANOFFSET (objfile->section_offsets, SECT_OFF_TEXT (objfile));
-
- /* We're in the global namespace. */
- processing_current_prefix = "";
- memset (&cu, 0, sizeof (struct dwarf2_cu));
- obstack_init (&cu.comp_unit_obstack);
- back_to = make_cleanup (free_stack_comp_unit, &cu);
+ cu = xmalloc (sizeof (struct dwarf2_cu));
+ memset (cu, 0, sizeof (struct dwarf2_cu));
- buildsym_init ();
- make_cleanup (really_free_pendings, NULL);
+ /* If an error occurs while loading, release our storage. */
+ free_cu_cleanup = make_cleanup (free_one_comp_unit, cu);
- cu.objfile = objfile;
+ cu->objfile = pst->objfile;
/* read in the comp_unit header */
- info_ptr = read_comp_unit_head (&cu.header, info_ptr, abfd);
+ info_ptr = read_comp_unit_head (&cu->header, info_ptr, abfd);
/* Read the abbrevs for this compilation unit */
- dwarf2_read_abbrevs (abfd, &cu);
- make_cleanup (dwarf2_free_abbrev_table, &cu);
+ dwarf2_read_abbrevs (abfd, cu);
+ back_to = make_cleanup (dwarf2_free_abbrev_table, cu);
+
+ cu->header.offset = offset;
+
+ cu->per_cu = per_cu;
+ per_cu->cu = cu;
+
+ /* We use this obstack for block values in dwarf_alloc_block. */
+ obstack_init (&cu->comp_unit_obstack);
- cu.header.offset = offset;
+ cu->dies = read_comp_unit (info_ptr, abfd, cu);
- cu.list_in_scope = &file_symbols;
+ /* 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);
- dies = read_comp_unit (info_ptr, abfd, &cu);
+ do_cleanups (back_to);
- make_cleanup_free_die_list (dies);
+ /* We've successfully allocated this compilation unit. Let our caller
+ clean it up when finished with it. */
+ discard_cleanups (free_cu_cleanup);
+
+ return cu;
+}
+
+/* Generate full symbol information for PST and CU, whose DIEs have
+ already been loaded into memory. */
+
+static void
+process_full_comp_unit (struct dwarf2_per_cu_data *per_cu)
+{
+ struct partial_symtab *pst = per_cu->psymtab;
+ struct dwarf2_cu *cu = per_cu->cu;
+ struct objfile *objfile = pst->objfile;
+ bfd *abfd = objfile->obfd;
+ CORE_ADDR lowpc, highpc;
+ struct symtab *symtab;
+ struct cleanup *back_to;
+ struct attribute *attr;
+ CORE_ADDR baseaddr;
+
+ baseaddr = ANOFFSET (objfile->section_offsets, SECT_OFF_TEXT (objfile));
+
+ /* We're in the global namespace. */
+ processing_current_prefix = "";
+
+ buildsym_init ();
+ back_to = make_cleanup (really_free_pendings, NULL);
+
+ cu->list_in_scope = &file_symbols;
/* Find the base address of the compilation unit for range lists and
location lists. It will normally be specified by DW_AT_low_pc.
@@ -2413,32 +2569,32 @@ psymtab_to_symtab_1 (struct partial_symt
DW_AT_entry_pc. It's been removed, but GCC still uses this for
compilation units with discontinuous ranges. */
- cu.header.base_known = 0;
- cu.header.base_address = 0;
+ cu->header.base_known = 0;
+ cu->header.base_address = 0;
- attr = dwarf2_attr (dies, DW_AT_entry_pc, &cu);
+ attr = dwarf2_attr (cu->dies, DW_AT_entry_pc, cu);
if (attr)
{
- cu.header.base_address = DW_ADDR (attr);
- cu.header.base_known = 1;
+ cu->header.base_address = DW_ADDR (attr);
+ cu->header.base_known = 1;
}
else
{
- attr = dwarf2_attr (dies, DW_AT_low_pc, &cu);
+ attr = dwarf2_attr (cu->dies, DW_AT_low_pc, cu);
if (attr)
{
- cu.header.base_address = DW_ADDR (attr);
- cu.header.base_known = 1;
+ cu->header.base_address = DW_ADDR (attr);
+ cu->header.base_known = 1;
}
}
/* Do line number decoding in read_file_scope () */
- process_die (dies, &cu);
+ process_die (cu->dies, cu);
/* Some compilers don't define a DW_AT_high_pc attribute for the
compilation unit. If the DW_AT_high_pc is missing, synthesize
it, by scanning the DIE's below the compilation unit. */
- get_scope_pc_bounds (dies, &lowpc, &highpc, &cu);
+ get_scope_pc_bounds (cu->dies, &lowpc, &highpc, cu);
symtab = end_symtab (highpc + baseaddr, objfile, SECT_OFF_TEXT (objfile));
@@ -2446,9 +2602,9 @@ psymtab_to_symtab_1 (struct partial_symt
If the compilation is from a C file generated by language preprocessors,
do not set the language if it was already deduced by start_subfile. */
if (symtab != NULL
- && !(cu.language == language_c && symtab->language != language_c))
+ && !(cu->language == language_c && symtab->language != language_c))
{
- symtab->language = cu.language;
+ symtab->language = cu->language;
}
pst->symtab = symtab;
pst->readin = 1;
@@ -4658,10 +4814,6 @@ read_subrange_type (struct die_info *die
static struct die_info *
read_comp_unit (char *info_ptr, bfd *abfd, struct dwarf2_cu *cu)
{
- /* Reset die reference table; we are
- building new ones now. */
- dwarf2_empty_hash_tables ();
-
return read_die_and_children (info_ptr, abfd, cu, &info_ptr, NULL);
}
@@ -4682,7 +4834,7 @@ read_die_and_children (char *info_ptr, b
int has_children;
cur_ptr = read_full_die (&die, abfd, info_ptr, cu, &has_children);
- store_in_ref_table (die->offset, die);
+ store_in_ref_table (die->offset, die, cu);
if (has_children)
{
@@ -4761,19 +4913,6 @@ free_die_list (struct die_info *dies)
}
}
-static void
-do_free_die_list_cleanup (void *dies)
-{
- free_die_list (dies);
-}
-
-static struct cleanup *
-make_cleanup_free_die_list (struct die_info *dies)
-{
- return make_cleanup (do_free_die_list_cleanup, dies);
-}
-
-
/* Read the contents of the section at OFFSET and of size SIZE from the
object file specified by OBJFILE into the objfile_obstack and return it. */
@@ -5313,27 +5452,16 @@ 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,
- struct dwarf2_cu **target_cu)
+find_partial_die (unsigned long offset, struct dwarf2_cu *cu)
{
struct dwarf2_per_cu_data *per_cu;
if (offset >= cu->header.offset
&& offset < cu->header.offset + cu->header.length)
- {
- *target_cu = cu;
- return find_partial_die_in_comp_unit (offset, cu);
- }
+ return find_partial_die_in_comp_unit (offset, cu);
per_cu = dwarf2_find_containing_comp_unit (offset, cu->objfile);
- /* If this offset isn't pointing into a known compilation unit,
- the debug information is probably corrupted. */
- if (per_cu == NULL)
- error ("Dwarf Error: could not find partial DIE containing "
- "offset 0x%lx [in module %s]",
- (long) offset, bfd_get_filename (cu->objfile->obfd));
-
if (per_cu->cu == NULL)
{
load_comp_unit (per_cu, cu->objfile);
@@ -5342,7 +5470,6 @@ find_partial_die (unsigned long offset,
}
per_cu->cu->last_used = 0;
- *target_cu = per_cu->cu;
return find_partial_die_in_comp_unit (offset, per_cu->cu);
}
@@ -5359,11 +5486,10 @@ fixup_partial_die (struct partial_die_in
if (part_die->name == NULL && part_die->has_specification)
{
struct partial_die_info *spec_die;
- struct dwarf2_cu *spec_cu;
- spec_die = find_partial_die (part_die->spec_offset, cu, &spec_cu);
+ spec_die = find_partial_die (part_die->spec_offset, cu);
- fixup_partial_die (spec_die, spec_cu);
+ fixup_partial_die (spec_die, cu);
if (spec_die->name)
{
@@ -5437,6 +5563,38 @@ read_full_die (struct die_info **diep, b
{
info_ptr = read_attribute (&die->attrs[i], &abbrev->attrs[i],
abfd, info_ptr, cu);
+
+ /* If this attribute is an absolute reference to a different
+ compilation unit, make sure that compilation unit is loaded
+ also. */
+ if (die->attrs[i].form == DW_FORM_ref_addr
+ && (DW_ADDR (&die->attrs[i]) < cu->header.offset
+ || (DW_ADDR (&die->attrs[i])
+ >= cu->header.offset + cu->header.length)))
+ {
+ struct dwarf2_per_cu_data *per_cu;
+ per_cu = dwarf2_find_containing_comp_unit (DW_ADDR (&die->attrs[i]),
+ cu->objfile);
+
+ /* Mark the dependence relation so that we don't flush PER_CU
+ too early. */
+ dwarf2_add_dependence (cu, per_cu);
+
+ /* If it's already on the queue, we have nothing to do. */
+ if (per_cu->queued)
+ continue;
+
+ /* If the compilation unit is already loaded, just mark it as
+ used. */
+ if (per_cu->cu != NULL)
+ {
+ per_cu->cu->last_used = 0;
+ continue;
+ }
+
+ /* Add it to the queue. */
+ queue_comp_unit (per_cu);
+ }
}
*diep = die;
@@ -5533,23 +5691,24 @@ read_attribute_value (struct attribute *
info_ptr += bytes_read;
break;
case DW_FORM_ref1:
- DW_UNSND (attr) = read_1_byte (abfd, info_ptr);
+ DW_ADDR (attr) = cu->header.offset + read_1_byte (abfd, info_ptr);
info_ptr += 1;
break;
case DW_FORM_ref2:
- DW_UNSND (attr) = read_2_bytes (abfd, info_ptr);
+ DW_ADDR (attr) = cu->header.offset + read_2_bytes (abfd, info_ptr);
info_ptr += 2;
break;
case DW_FORM_ref4:
- DW_UNSND (attr) = read_4_bytes (abfd, info_ptr);
+ DW_ADDR (attr) = cu->header.offset + read_4_bytes (abfd, info_ptr);
info_ptr += 4;
break;
case DW_FORM_ref8:
- DW_UNSND (attr) = read_8_bytes (abfd, info_ptr);
+ DW_ADDR (attr) = cu->header.offset + read_8_bytes (abfd, info_ptr);
info_ptr += 8;
break;
case DW_FORM_ref_udata:
- DW_UNSND (attr) = read_unsigned_leb128 (abfd, info_ptr, &bytes_read);
+ DW_ADDR (attr) = (cu->header.offset
+ + read_unsigned_leb128 (abfd, info_ptr, &bytes_read));
info_ptr += bytes_read;
break;
case DW_FORM_indirect:
@@ -5957,21 +6116,14 @@ dwarf2_attr (struct die_info *die, unsig
for (i = 0; i < die->num_attrs; ++i)
{
if (die->attrs[i].name == name)
- {
- return &die->attrs[i];
- }
+ return &die->attrs[i];
if (die->attrs[i].name == DW_AT_specification
|| die->attrs[i].name == DW_AT_abstract_origin)
spec = &die->attrs[i];
}
- if (spec)
- {
- struct die_info *ref_die =
- follow_die_ref (dwarf2_get_ref_die_offset (spec, cu));
- if (ref_die)
- return dwarf2_attr (ref_die, name, cu);
- }
+ if (spec)
+ return dwarf2_attr (follow_die_ref (die, spec, cu), name, cu);
return NULL;
}
@@ -6013,7 +6165,7 @@ die_specification (struct die_info *die,
if (spec_attr == NULL)
return NULL;
else
- return follow_die_ref (dwarf2_get_ref_die_offset (spec_attr, cu));
+ return follow_die_ref (die, spec_attr, cu);
}
/* Free the line_header structure *LH, and any arrays and strings it
@@ -6944,7 +7096,6 @@ die_type (struct die_info *die, struct d
struct type *type;
struct attribute *type_attr;
struct die_info *type_die;
- unsigned int ref;
type_attr = dwarf2_attr (die, DW_AT_type, cu);
if (!type_attr)
@@ -6953,16 +7104,8 @@ die_type (struct die_info *die, struct d
return dwarf2_fundamental_type (cu->objfile, FT_VOID, cu);
}
else
- {
- ref = dwarf2_get_ref_die_offset (type_attr, cu);
- type_die = follow_die_ref (ref);
- if (!type_die)
- {
- error ("Dwarf Error: Cannot find referent at offset %d [in module %s]",
- ref, cu->objfile->name);
- return NULL;
- }
- }
+ type_die = follow_die_ref (die, type_attr, cu);
+
type = tag_type_to_type (type_die, cu);
if (!type)
{
@@ -6982,19 +7125,11 @@ die_containing_type (struct die_info *di
struct type *type = NULL;
struct attribute *type_attr;
struct die_info *type_die = NULL;
- unsigned int ref;
type_attr = dwarf2_attr (die, DW_AT_containing_type, cu);
if (type_attr)
{
- ref = dwarf2_get_ref_die_offset (type_attr, cu);
- type_die = follow_die_ref (ref);
- if (!type_die)
- {
- error ("Dwarf Error: Cannot find referent at offset %d [in module %s]", ref,
- cu->objfile->name);
- return NULL;
- }
+ type_die = follow_die_ref (die, type_attr, cu);
type = tag_type_to_type (type_die, cu);
}
if (!type)
@@ -7007,24 +7142,6 @@ die_containing_type (struct die_info *di
return type;
}
-#if 0
-static struct type *
-type_at_offset (unsigned int offset, struct dwarf2_cu *cu)
-{
- struct die_info *die;
- struct type *type;
-
- die = follow_die_ref (offset);
- if (!die)
- {
- error ("Dwarf Error: Cannot find type referent at offset %d.", offset);
- return NULL;
- }
- type = tag_type_to_type (die, cu);
- return type;
-}
-#endif
-
static struct type *
tag_type_to_type (struct die_info *die, struct dwarf2_cu *cu)
{
@@ -7378,21 +7495,12 @@ static struct die_info *
dwarf2_extension (struct die_info *die, struct dwarf2_cu *cu)
{
struct attribute *attr;
- struct die_info *extension_die;
- unsigned int ref;
attr = dwarf2_attr (die, DW_AT_extension, cu);
if (attr == NULL)
return NULL;
- ref = dwarf2_get_ref_die_offset (attr, cu);
- extension_die = follow_die_ref (ref);
- if (!extension_die)
- {
- error ("Dwarf Error: Cannot find referent at offset %d.", ref);
- }
-
- return extension_die;
+ return follow_die_ref (die, attr, cu);
}
/* Convert a DIE tag into its string name. */
@@ -8229,13 +8337,16 @@ dump_die (struct die_info *die)
case DW_FORM_block1:
fprintf_unfiltered (gdb_stderr, "block: size %d", DW_BLOCK (&die->attrs[i])->size);
break;
+ case DW_FORM_ref1:
+ case DW_FORM_ref2:
+ case DW_FORM_ref4:
+ fprintf_unfiltered (gdb_stderr, "constant ref: %ld (adjusted)",
+ (long) (DW_ADDR (&die->attrs[i])));
+ break;
case DW_FORM_data1:
case DW_FORM_data2:
case DW_FORM_data4:
case DW_FORM_data8:
- case DW_FORM_ref1:
- case DW_FORM_ref2:
- case DW_FORM_ref4:
case DW_FORM_udata:
case DW_FORM_sdata:
fprintf_unfiltered (gdb_stderr, "constant: %ld", DW_UNSND (&die->attrs[i]));
@@ -8279,22 +8390,16 @@ dump_die_list (struct die_info *die)
}
static void
-store_in_ref_table (unsigned int offset, struct die_info *die)
+store_in_ref_table (unsigned int offset, struct die_info *die,
+ struct dwarf2_cu *cu)
{
int h;
struct die_info *old;
h = (offset % REF_HASH_SIZE);
- old = die_ref_table[h];
+ old = cu->die_ref_table[h];
die->next_ref = old;
- die_ref_table[h] = die;
-}
-
-
-static void
-dwarf2_empty_hash_tables (void)
-{
- memset (die_ref_table, 0, sizeof (die_ref_table));
+ cu->die_ref_table[h] = die;
}
static unsigned int
@@ -8305,14 +8410,12 @@ dwarf2_get_ref_die_offset (struct attrib
switch (attr->form)
{
case DW_FORM_ref_addr:
- result = DW_ADDR (attr);
- break;
case DW_FORM_ref1:
case DW_FORM_ref2:
case DW_FORM_ref4:
case DW_FORM_ref8:
case DW_FORM_ref_udata:
- result = cu->header.offset + DW_UNSND (attr);
+ result = DW_ADDR (attr);
break;
default:
complaint (&symfile_complaints,
@@ -8345,21 +8448,41 @@ dwarf2_get_attr_constant_value (struct a
}
static struct die_info *
-follow_die_ref (unsigned int offset)
+follow_die_ref (struct die_info *src_die, struct attribute *attr,
+ struct dwarf2_cu *cu)
{
struct die_info *die;
+ unsigned int offset;
int h;
+ struct die_info temp_die;
+ struct dwarf2_cu *target_cu;
+
+ offset = dwarf2_get_ref_die_offset (attr, cu);
+
+ if (DW_ADDR (attr) < cu->header.offset
+ || DW_ADDR (attr) >= cu->header.offset + cu->header.length)
+ {
+ struct dwarf2_per_cu_data *per_cu;
+ per_cu = dwarf2_find_containing_comp_unit (DW_ADDR (attr),
+ cu->objfile);
+ target_cu = per_cu->cu;
+ }
+ else
+ target_cu = cu;
h = (offset % REF_HASH_SIZE);
- die = die_ref_table[h];
+ die = target_cu->die_ref_table[h];
while (die)
{
if (die->offset == offset)
- {
- return die;
- }
+ return die;
die = die->next_ref;
}
+
+ error ("Dwarf Error: Cannot find DIE at 0x%lx referenced from DIE "
+ "at 0x%lx [in module %s]",
+ (long) src_die->offset, (long) offset, cu->objfile->name);
+
return NULL;
}
@@ -9089,7 +9212,7 @@ dwarf2_symbol_mark_computed (struct attr
}
/* Locate the compilation unit from CU's objfile which contains the
- DIE at OFFSET. Returns NULL on failure. */
+ DIE at OFFSET. Raises an error on failure. */
static struct dwarf2_per_cu_data *
dwarf2_find_containing_comp_unit (unsigned long offset,
@@ -9098,11 +9221,6 @@ dwarf2_find_containing_comp_unit (unsign
struct dwarf2_per_cu_data *this_cu;
int low, high;
- if (dwarf2_per_objfile->all_comp_units == NULL)
- error ("Dwarf Error: offset 0x%lx points outside this "
- "compilation unit [in module %s]",
- offset, bfd_get_filename (objfile->obfd));
-
low = 0;
high = dwarf2_per_objfile->n_comp_units - 1;
while (high > low)
@@ -9116,7 +9234,11 @@ dwarf2_find_containing_comp_unit (unsign
gdb_assert (low == high);
if (dwarf2_per_objfile->all_comp_units[low]->offset > offset)
{
- gdb_assert (low > 0);
+ if (low == 0)
+ error ("Dwarf Error: could not find partial DIE containing "
+ "offset 0x%lx [in module %s]",
+ (long) offset, bfd_get_filename (objfile->obfd));
+
gdb_assert (dwarf2_per_objfile->all_comp_units[low-1]->offset <= offset);
return dwarf2_per_objfile->all_comp_units[low-1];
}
@@ -9131,6 +9253,9 @@ dwarf2_find_containing_comp_unit (unsign
}
}
+/* Locate the compilation unit from OBJFILE which is located at exactly
+ OFFSET. Raises an error on failure. */
+
static struct dwarf2_per_cu_data *
dwarf2_find_comp_unit (unsigned long offset, struct objfile *objfile)
{
@@ -9155,6 +9280,8 @@ free_one_comp_unit (void *data)
cu->per_cu = NULL;
obstack_free (&cu->comp_unit_obstack, NULL);
+ if (cu->dies)
+ free_die_list (cu->dies);
xfree (cu);
}
@@ -9335,8 +9462,6 @@ set_die_type (struct die_info *die, stru
**slot = ofs;
}
-#if 0
-
/* Find the type for DIE in TYPE_HASH, or return NULL if DIE does not
have a saved type. */
@@ -9372,17 +9497,56 @@ reset_die_and_siblings_types (struct die
}
}
-#endif
+/* Set the mark field in CU and in every other compilation unit in the
+ cache that we must keep because we are keeping CU. */
+
+/* Add a dependence relationship from CU to REF_PER_CU. */
+
+static void
+dwarf2_add_dependence (struct dwarf2_cu *cu,
+ struct dwarf2_per_cu_data *ref_per_cu)
+{
+ void **slot;
+
+ if (cu->dependencies == NULL)
+ cu->dependencies
+ = htab_create_alloc_ex (5, htab_hash_pointer, htab_eq_pointer,
+ NULL, &cu->comp_unit_obstack,
+ hashtab_obstack_allocate,
+ dummy_obstack_deallocate);
+
+ slot = htab_find_slot (cu->dependencies, ref_per_cu, INSERT);
+ if (*slot == NULL)
+ *slot = ref_per_cu;
+}
/* Set the mark field in CU and in every other compilation unit in the
cache that we must keep because we are keeping CU. */
+static int
+dwarf2_mark_helper (void **slot, void *data)
+{
+ struct dwarf2_per_cu_data *per_cu;
+
+ per_cu = (struct dwarf2_per_cu_data *) *slot;
+ if (per_cu->cu->mark)
+ return 1;
+ per_cu->cu->mark = 1;
+
+ if (per_cu->cu->dependencies != NULL)
+ htab_traverse (per_cu->cu->dependencies, dwarf2_mark_helper, NULL);
+
+ return 1;
+}
+
static void
dwarf2_mark (struct dwarf2_cu *cu)
{
if (cu->mark)
return;
cu->mark = 1;
+ if (cu->dependencies != NULL)
+ htab_traverse (cu->dependencies, dwarf2_mark_helper, NULL);
}
static void
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