Yao Qi <yao@codesourcery.com> writes:
> Doug Evans <xdje42@gmail.com> writes:
>
> Some comments on indentation.
>
>> /* Restart compilation for a symtab.
>> + CUST is the result of end_expandable_symtab.
>> + NAME,START_ADDR are the source file we are resuming with.
>
> Space after comma is missing.
>
>>
>> /* Subroutine of end_symtab_from_static_block to simplify it.
>> Handle the "no blockvector" case.
>> - When this happens there is nothing to record, so just free up
>> - any memory we allocated while reading debug info. */
>> + When this happens there is nothing to record, so there's nothing to do:
>> + memory will be freed up later.
>> + This function is kept to have a place to document the issues. */
>>
>> static void
>> end_symtab_without_blockvector (void)
>> {
>> - /* Free up all the subfiles.
>> - We won't be adding a compunit to the objfile's list of compunits,
>> + /* Note: We won't be adding a compunit to the objfile's list of compunits,
>> so there's nothing to unchain. However, since each symtab
>> is added to the objfile's obstack we can't free that space.
>> We could do better, but this is believed to be a sufficiently rare
>> event. */
>> - free_buildsym_compunit ();
>> }
>
> end_symtab_without_blockvector is empty, so remove it?
Hi.
Here's what I committed.
2014-12-16 Doug Evans <xdje42@gmail.com>
* buildsym.c: Add comments describing how the buildsym machinery
is used by the various file formats.
(really_free_pendings): Enhance function comment.
See pending_macros to NULL. Simplify resetting pending_addrmap.
Call free_buildsym_compunit.
(free_buildsym_compunit): Set current_subfile to NULL.
(prepare_for_building): New function.
(start_symtab): Call it. Remove call to set_last_source_file.
(restart_symtab): New arg "cust". All callers updated.
Simplify, call prepare_for_building. Re-initialize buildsym_compunit.
(reset_symtab_globals): Enhance function comment.
Set local_symbols, file_symbols, global_symbols to NULL.
Set pending_macros to NULL. Simplify resetting pending_addrmap.
Call free_buildysym_compunit.
(end_symtab_without_blockvector): Delete. All callers updated.
(end_symtab_with_blockvector): Remove redundant call to
free_buildsym_compunit.
(augment_type_symtab): Remove arg "cust". All callers updated.
(buildsym_init): Remove resetting of free_pendings, file_symbols,
global_symbols, pending_blocks, pending_macros. Instead make
handling consistent with pending_addrmap: Assert value was reset
at end of previous symtab building. Initialize context_stack here.
@@ -21,7 +21,53 @@
file-reading routines.
Routines to support specific debugging information formats (stabs,
- DWARF, etc) belong somewhere else. */
+ DWARF, etc) belong somewhere else.
+
+ The basic way this module is used is as follows:
+
+ buildsym_init ();
+ cleanups = make_cleanup (really_free_pendings, NULL);
+ cust = start_symtab (...);
+ ... read debug info ...
+ cust = end_symtab (...);
+ do_cleanups (cleanups);
+
+ The compunit symtab pointer ("cust") is returned from both start_symtab
+ and end_symtab to simplify the debug info readers.
+
+ There are minor variations on this, e.g., dwarf2read.c splits end_symtab
+ into two calls: end_symtab_get_static_block, end_symtab_from_static_block,
+ but all debug info readers follow this basic flow.
+
+ Reading DWARF Type Units is another variation:
+
+ buildsym_init ();
+ cleanups = make_cleanup (really_free_pendings, NULL);
+ cust = start_symtab (...);
+ ... read debug info ...
+ cust = end_expandable_symtab (...);
+ do_cleanups (cleanups);
+
+ And then reading subsequent Type Units within the containing "Comp Unit"
+ will use a second flow:
+
+ buildsym_init ();
+ cleanups = make_cleanup (really_free_pendings, NULL);
+ cust = restart_symtab (...);
+ ... read debug info ...
+ cust = augment_type_symtab (...);
+ do_cleanups (cleanups);
+
+ dbxread.c and xcoffread.c use another variation:
+
+ buildsym_init ();
+ cleanups = make_cleanup (really_free_pendings, NULL);
+ cust = start_symtab (...);
+ ... read debug info ...
+ cust = end_symtab (...);
+ ... start_symtab + read + end_symtab repeated ...
+ do_cleanups (cleanups);
+*/
#include "defs.h"
#include "bfd.h"
@@ -146,6 +192,8 @@ static struct subfile_stack *subfile_stack;
currently reading. */
static struct macro_table *pending_macros;
+static void free_buildsym_compunit (void);
+
static int compare_line_numbers (const void *ln1p, const void *ln2p);
static void record_pending_block (struct objfile *objfile,
@@ -220,8 +268,12 @@ find_symbol_in_list (struct pending *list, char *name, int length)
return (NULL);
}
-/* At end of reading syms, or in case of quit, really free as many
- `struct pending's as we can easily find. */
+/* At end of reading syms, or in case of quit, ensure everything associated
+ with building symtabs is freed. This is intended to be registered as a
+ cleanup before doing psymtab->symtab expansion.
+
+ N.B. This is *not* intended to be used when building psymtabs. Some debug
+ info readers call this anyway, which is harmless if confusing. */
void
really_free_pendings (void *dummy)
@@ -253,12 +305,13 @@ really_free_pendings (void *dummy)
if (pending_macros)
free_macro_table (pending_macros);
+ pending_macros = NULL;
if (pending_addrmap)
- {
- obstack_free (&pending_addrmap_obstack, NULL);
- pending_addrmap = NULL;
- }
+ obstack_free (&pending_addrmap_obstack, NULL);
+ pending_addrmap = NULL;
+
+ free_buildsym_compunit ();
}
/* This function is called to discard any pending blocks. */
@@ -744,6 +797,7 @@ free_buildsym_compunit (void)
xfree (buildsym_compunit->comp_dir);
xfree (buildsym_compunit);
buildsym_compunit = NULL;
+ current_subfile = NULL;
}
/* For stabs readers, the first N_SO symbol is assumed to be the
@@ -943,6 +997,32 @@ get_macro_table (void)
return pending_macros;
}
+/* Init state to prepare for building a symtab.
+ Note: This can't be done in buildsym_init because dbxread.c and xcoffread.c
+ can call start_symtab+end_symtab multiple times after one call to
+ buildsym_init. */
+
+static void
+prepare_for_building (const char *name, CORE_ADDR start_addr)
+{
+ set_last_source_file (name);
+ last_source_start_addr = start_addr;
+
+ local_symbols = NULL;
+ within_function = 0;
+ have_line_numbers = 0;
+
+ context_stack_depth = 0;
+
+ /* These should have been reset either by successful completion of building
+ a symtab, or by the really_free_pendings cleanup. */
+ gdb_assert (file_symbols == NULL);
+ gdb_assert (global_symbols == NULL);
+ gdb_assert (pending_macros == NULL);
+ gdb_assert (pending_addrmap == NULL);
+ gdb_assert (current_subfile == NULL);
+}
+
/* Start a new symtab for a new source file in OBJFILE. Called, for example,
when a stabs symbol of type N_SO is seen, or when a DWARF
TAG_compile_unit DIE is seen. It indicates the start of data for
@@ -956,11 +1036,11 @@ struct compunit_symtab *
start_symtab (struct objfile *objfile, const char *name, const char *comp_dir,
CORE_ADDR start_addr)
{
- restart_symtab (start_addr);
+ prepare_for_building (name, start_addr);
buildsym_compunit = start_buildsym_compunit (objfile, comp_dir);
- /* Allocate the primary symtab now. The caller needs it to allocate
+ /* Allocate the compunit symtab now. The caller needs it to allocate
non-primary symtabs. It is also needed by get_macro_table. */
buildsym_compunit->compunit_symtab = allocate_compunit_symtab (objfile,
name);
@@ -976,43 +1056,27 @@ start_symtab (struct objfile *objfile, const char *name, const char *comp_dir,
of the subfiles list. */
buildsym_compunit->main_subfile = current_subfile;
- set_last_source_file (name);
-
return buildsym_compunit->compunit_symtab;
}
/* Restart compilation for a symtab.
+ CUST is the result of end_expandable_symtab.
+ NAME, START_ADDR are the source file we are resuming with.
+
This is used when a symtab is built from multiple sources.
- The symtab is first built with start_symtab and then for each additional
- piece call restart_symtab. */
+ The symtab is first built with start_symtab/end_expandable_symtab
+ and then for each additional piece call restart_symtab/augment_*_symtab.
+ Note: At the moment there is only augment_type_symtab. */
void
-restart_symtab (CORE_ADDR start_addr)
+restart_symtab (struct compunit_symtab *cust,
+ const char *name, CORE_ADDR start_addr)
{
- set_last_source_file (NULL);
- last_source_start_addr = start_addr;
- file_symbols = NULL;
- global_symbols = NULL;
- within_function = 0;
- have_line_numbers = 0;
+ prepare_for_building (name, start_addr);
- /* Context stack is initially empty. Allocate first one with room
- for 10 levels; reuse it forever afterward. */
- if (context_stack == NULL)
- {
- context_stack_size = INITIAL_CONTEXT_STACK_SIZE;
- context_stack = (struct context_stack *)
- xmalloc (context_stack_size * sizeof (struct context_stack));
- }
- context_stack_depth = 0;
-
- /* We shouldn't have any address map at this point. */
- gdb_assert (! pending_addrmap);
-
- /* Reset the sub source files list. The list should already be empty,
- but free it anyway in case some code didn't finish cleaning up after
- an error. */
- free_buildsym_compunit ();
+ buildsym_compunit = start_buildsym_compunit (COMPUNIT_OBJFILE (cust),
+ COMPUNIT_DIRNAME (cust));
+ buildsym_compunit->compunit_symtab = cust;
}
/* Subroutine of end_symtab to simplify it. Look for a subfile that
@@ -1101,19 +1165,30 @@ block_compar (const void *ap, const void *bp)
- (BLOCK_START (b) < BLOCK_START (a)));
}
-/* Reset globals used to build symtabs. */
+/* Reset state after a successful building of a symtab.
+ This exists because dbxread.c and xcoffread.c can call
+ start_symtab+end_symtab multiple times after one call to buildsym_init,
+ and before the really_free_pendings cleanup is called.
+ We keep the free_pendings list around for dbx/xcoff sake. */
static void
reset_symtab_globals (void)
{
set_last_source_file (NULL);
- free_buildsym_compunit ();
+
+ local_symbols = NULL;
+ file_symbols = NULL;
+ global_symbols = NULL;
+
+ /* We don't free pending_macros here because if the symtab was successfully
+ built then ownership was transferred to the symtab. */
pending_macros = NULL;
+
if (pending_addrmap)
- {
- obstack_free (&pending_addrmap_obstack, NULL);
- pending_addrmap = NULL;
- }
+ obstack_free (&pending_addrmap_obstack, NULL);
+ pending_addrmap = NULL;
+
+ free_buildsym_compunit ();
}
/* Implementation of the first part of end_symtab. It allows modifying
@@ -1221,23 +1296,6 @@ end_symtab_get_static_block (CORE_ADDR end_addr, int expandable, int required)
}
/* Subroutine of end_symtab_from_static_block to simplify it.
- Handle the "no blockvector" case.
- When this happens there is nothing to record, so just free up
- any memory we allocated while reading debug info. */
-
-static void
-end_symtab_without_blockvector (void)
-{
- /* Free up all the subfiles.
- We won't be adding a compunit to the objfile's list of compunits,
- so there's nothing to unchain. However, since each symtab
- is added to the objfile's obstack we can't free that space.
- We could do better, but this is believed to be a sufficiently rare
- event. */
- free_buildsym_compunit ();
-}
-
-/* Subroutine of end_symtab_from_static_block to simplify it.
Handle the "have blockvector" case.
See end_symtab_from_static_block for a description of the arguments. */
@@ -1349,7 +1407,7 @@ end_symtab_with_blockvector (struct block *static_block,
gdb_assert (main_symtab == COMPUNIT_FILETABS (cu));
}
- /* Fill out the primary symtab. */
+ /* Fill out the compunit symtab. */
if (buildsym_compunit->comp_dir != NULL)
{
@@ -1406,7 +1464,6 @@ end_symtab_with_blockvector (struct block *static_block,
}
add_compunit_symtab_to_objfile (cu);
- free_buildsym_compunit ();
return cu;
}
@@ -1428,7 +1485,15 @@ end_symtab_from_static_block (struct block *static_block,
if (static_block == NULL)
{
- end_symtab_without_blockvector ();
+ /* Handle the "no blockvector" case.
+ When this happens there is nothing to record, so there's nothing
+ to do: memory will be freed up later.
+
+ Note: We won't be adding a compunit to the objfile's list of
+ compunits, so there's nothing to unchain. However, since each symtab
+ is added to the objfile's obstack we can't free that space.
+ We could do better, but this is believed to be a sufficiently rare
+ event. */
cu = NULL;
}
else
@@ -1506,8 +1571,9 @@ set_missing_symtab (struct pending *pending_list,
This is the case for DWARF4 Type Units. */
void
-augment_type_symtab (struct compunit_symtab *cust)
+augment_type_symtab (void)
{
+ struct compunit_symtab *cust = buildsym_compunit->compunit_symtab;
const struct blockvector *blockvector = COMPUNIT_BLOCKVECTOR (cust);
if (context_stack_depth > 0)
@@ -1674,17 +1740,29 @@ get_last_source_file (void)
void
buildsym_init (void)
{
- free_pendings = NULL;
- file_symbols = NULL;
- global_symbols = NULL;
- pending_blocks = NULL;
- pending_macros = NULL;
using_directives = NULL;
subfile_stack = NULL;
- /* We shouldn't have any address map at this point. */
- gdb_assert (! pending_addrmap);
pending_addrmap_interesting = 0;
+
+ /* Context stack is initially empty. Allocate first one with room
+ for a few levels; reuse it forever afterward. */
+ if (context_stack == NULL)
+ {
+ context_stack_size = INITIAL_CONTEXT_STACK_SIZE;
+ context_stack = (struct context_stack *)
+ xmalloc (context_stack_size * sizeof (struct context_stack));
+ }
+
+ /* Ensure the really_free_pendings cleanup was called after
+ the last time. */
+ gdb_assert (free_pendings == NULL);
+ gdb_assert (pending_blocks == NULL);
+ gdb_assert (file_symbols == NULL);
+ gdb_assert (global_symbols == NULL);
+ gdb_assert (pending_macros == NULL);
+ gdb_assert (pending_addrmap == NULL);
+ gdb_assert (buildsym_compunit == NULL);
}
/* Initialize anything that needs initializing when a completely new
@@ -222,7 +222,7 @@ extern struct compunit_symtab *end_symtab (CORE_ADDR end_addr, int section);
extern struct compunit_symtab *end_expandable_symtab (CORE_ADDR end_addr,
int section);
-extern void augment_type_symtab (struct compunit_symtab *cust);
+extern void augment_type_symtab (void);
/* Defined in stabsread.c. */
@@ -243,7 +243,8 @@ extern struct compunit_symtab *start_symtab (struct objfile *objfile,
const char *comp_dir,
CORE_ADDR start_addr);
-extern void restart_symtab (CORE_ADDR start_addr);
+extern void restart_symtab (struct compunit_symtab *cust,
+ const char *name, CORE_ADDR start_addr);
extern int hashname (const char *name);
@@ -8093,7 +8093,7 @@ process_full_type_unit (struct dwarf2_per_cu_data *per_cu,
}
else
{
- augment_type_symtab (sig_type->type_unit_group->compunit_symtab);
+ augment_type_symtab ();
cust = sig_type->type_unit_group->compunit_symtab;
}
@@ -9149,7 +9149,7 @@ setup_type_unit_groups (struct die_info *die, struct dwarf2_cu *cu)
else
{
gdb_assert (tu_group->symtabs == NULL);
- restart_symtab (0);
+ restart_symtab (tu_group->compunit_symtab, "", 0);
}
/* Note: The compunit symtab will get allocated at the end. */
return;
@@ -9190,7 +9190,7 @@ setup_type_unit_groups (struct die_info *die, struct dwarf2_cu *cu)
}
else
{
- restart_symtab (0);
+ restart_symtab (tu_group->compunit_symtab, "", 0);
for (i = 0; i < lh->num_file_names; ++i)
{