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Split up end_symtab_from_static_block into two.

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This patch is conceptually quite simple.
If you look at end_symtab_from_static_block you'll see
that the static_block == NULL case is completely different
than the non-NULL case.

There's a lot of complexity to handle the NULL case but it seems
entirely unnecessary.  For example, whether blockvector is NULL
is decided at the start, before this for loop:

  for (subfile = subfiles; subfile; subfile = nextsub)

Secondly, after the for loop, we test symtab for non-NULL here:

  /* Set this for the main source file.  */
  if (symtab)

but symtab will only ever be non-NULL if blockvector was non-NULL.
And if blockvector was non_NULL so will symtab.

The other case to consider is these lines of code executed before
the for loop:

  /* Read the line table if it has to be read separately.
     This is only used by xcoffread.c.  */
  if (objfile->sf->sym_read_linetable != NULL)
    objfile->sf->sym_read_linetable (objfile);

  /* Handle the case where the debug info specifies a different path
     for the main source file.  It can cause us to lose track of its
     line number information.  */
  watch_main_source_file_lossage ();

From my reading of the code, neither of these is useful
in the static_block == NULL case.

Thus we can make the code more readable by splitting these two cases up,
which is what this patch does.

gdb/ChangeLog:

	* buildsym.c (main_subfile): New static global.
	(free_subfiles_list): New function.
	(start_symtab): Set main_subfile.
	(restart_symtab): Replace init of subfiles, current_subfile with
	call to free_subfiles_list.
	(watch_main_source_file_lossage): Use main_subfile.
	(reset_symtab_globals): Replace init of current_subfile with call
	to free_subfiles_list.
	(end_symtab_without_blockvector, end_symtab_with_blockvector): New
	functions, split out from ...
	(end_symtab_from_static_block): ... here.  Rewrite to call them.
This commit is contained in:
Doug Evans 2014-11-18 08:28:04 -08:00
parent f194fefb5e
commit 7bab9b58fd
2 changed files with 252 additions and 216 deletions
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14
gdb/ChangeLog
View file

@ -1,3 +1,17 @@
2014-11-18 Doug Evans <xdje42@gmail.com>
* buildsym.c (main_subfile): New static global.
(free_subfiles_list): New function.
(start_symtab): Set main_subfile.
(restart_symtab): Replace init of subfiles, current_subfile with
call to free_subfiles_list.
(watch_main_source_file_lossage): Use main_subfile.
(reset_symtab_globals): Replace init of current_subfile with call
to free_subfiles_list.
(end_symtab_without_blockvector, end_symtab_with_blockvector): New
functions, split out from ...
(end_symtab_from_static_block): ... here. Rewrite to call them.
2014-11-18 Doug Evans <xdje42@gmail.com>
The result of symtab expansion is always a primary symtab.

454
gdb/buildsym.c
View file

@ -56,6 +56,12 @@
static struct subfile *subfiles;
/* The "main" subfile.
In C this is the ".c" file (and similarly for other languages).
This becomes the "primary" symtab of the compilation unit. */
static struct subfile *main_subfile;
/* List of free `struct pending' structures for reuse. */
static struct pending *free_pendings;
@ -670,6 +676,26 @@ start_subfile (const char *name, const char *dirname)
}
}
/* Delete the subfiles list. */
static void
free_subfiles_list (void)
{
struct subfile *subfile, *nextsub;
for (subfile = subfiles; subfile != NULL; subfile = nextsub)
{
nextsub = subfile->next;
xfree (subfile->name);
xfree (subfile->dirname);
xfree (subfile->line_vector);
xfree (subfile);
}
subfiles = NULL;
current_subfile = NULL;
main_subfile = NULL;
}
/* For stabs readers, the first N_SO symbol is assumed to be the
source file name, and the subfile struct is initialized using that
assumption. If another N_SO symbol is later seen, immediately
@ -862,6 +888,9 @@ start_symtab (const char *name, const char *dirname, CORE_ADDR start_addr)
restart_symtab (start_addr);
set_last_source_file (name);
start_subfile (name, dirname);
/* Save this so that we don't have to go looking for it at the end
of the subfiles list. */
main_subfile = current_subfile;
}
/* Restart compilation for a symtab.
@ -892,10 +921,10 @@ restart_symtab (CORE_ADDR start_addr)
/* We shouldn't have any address map at this point. */
gdb_assert (! pending_addrmap);
/* Initialize the list of sub source files with one entry for this
file (the top-level source file). */
subfiles = NULL;
current_subfile = NULL;
/* 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_subfiles_list ();
}
/* Subroutine of end_symtab to simplify it. Look for a subfile that
@ -910,30 +939,20 @@ restart_symtab (CORE_ADDR start_addr)
static void
watch_main_source_file_lossage (void)
{
struct subfile *mainsub, *subfile;
struct subfile *subfile;
/* Find the main source file.
This loop could be eliminated if start_symtab saved it for us. */
mainsub = NULL;
for (subfile = subfiles; subfile; subfile = subfile->next)
{
/* The main subfile is guaranteed to be the last one. */
if (subfile->next == NULL)
mainsub = subfile;
}
/* We have to watch for mainsub == NULL here. It's a quirk of
end_symtab, it can return NULL so there may not be a main subfile. */
if (main_subfile == NULL)
return;
/* If the main source file doesn't have any line number or symbol
info, look for an alias in another subfile.
info, look for an alias in another subfile. */
We have to watch for mainsub == NULL here. It's a quirk of
end_symtab, it can return NULL so there may not be a main
subfile. */
if (mainsub
&& mainsub->line_vector == NULL
&& mainsub->symtab == NULL)
if (main_subfile->line_vector == NULL
&& main_subfile->symtab == NULL)
{
const char *mainbase = lbasename (mainsub->name);
const char *mainbase = lbasename (main_subfile->name);
int nr_matches = 0;
struct subfile *prevsub;
struct subfile *mainsub_alias = NULL;
@ -956,15 +975,15 @@ watch_main_source_file_lossage (void)
if (nr_matches == 1)
{
gdb_assert (mainsub_alias != NULL && mainsub_alias != mainsub);
gdb_assert (mainsub_alias != NULL && mainsub_alias != main_subfile);
/* Found a match for the main source file.
Copy its line_vector and symtab to the main subfile
and then discard it. */
mainsub->line_vector = mainsub_alias->line_vector;
mainsub->line_vector_length = mainsub_alias->line_vector_length;
mainsub->symtab = mainsub_alias->symtab;
main_subfile->line_vector = mainsub_alias->line_vector;
main_subfile->line_vector_length = mainsub_alias->line_vector_length;
main_subfile->symtab = mainsub_alias->symtab;
if (prev_mainsub_alias == NULL)
subfiles = mainsub_alias->next;
@ -994,7 +1013,7 @@ static void
reset_symtab_globals (void)
{
set_last_source_file (NULL);
current_subfile = NULL;
free_subfiles_list ();
pending_macros = NULL;
if (pending_addrmap)
{
@ -1106,6 +1125,191 @@ end_symtab_get_static_block (CORE_ADDR end_addr, struct objfile *objfile,
}
}
/* 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 (struct objfile *objfile)
{
struct subfile *subfile;
/* Since we are ignoring these subfiles, we also need
to unlink the associated empty symtab that we created.
Otherwise, we can run into trouble because various parts
such as the block-vector are uninitialized whereas
the rest of the code assumes that they are.
We can only unlink the symtab. We can't free it because
it was allocated on the objfile obstack. */
for (subfile = subfiles; subfile != NULL; subfile = subfile->next)
{
if (subfile->symtab)
{
struct symtab *s;
if (objfile->symtabs == subfile->symtab)
objfile->symtabs = objfile->symtabs->next;
else
ALL_OBJFILE_SYMTABS (objfile, s)
if (s->next == subfile->symtab)
{
s->next = s->next->next;
break;
}
subfile->symtab = NULL;
}
}
}
/* 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. */
static struct symtab *
end_symtab_with_blockvector (struct block *static_block,
struct objfile *objfile, int section,
int expandable)
{
struct symtab *symtab;
struct blockvector *blockvector;
struct subfile *subfile;
CORE_ADDR end_addr;
gdb_assert (static_block != NULL);
gdb_assert (subfiles != NULL);
end_addr = BLOCK_END (static_block);
/* Create the GLOBAL_BLOCK and build the blockvector. */
finish_block_internal (NULL, &global_symbols, NULL,
last_source_start_addr, end_addr, objfile,
1, expandable);
blockvector = make_blockvector (objfile);
/* Read the line table if it has to be read separately.
This is only used by xcoffread.c. */
if (objfile->sf->sym_read_linetable != NULL)
objfile->sf->sym_read_linetable (objfile);
/* Handle the case where the debug info specifies a different path
for the main source file. It can cause us to lose track of its
line number information. */
watch_main_source_file_lossage ();
/* Now create the symtab objects proper, one for each subfile. */
for (subfile = subfiles; subfile != NULL; subfile = subfile->next)
{
int linetablesize = 0;
if (subfile->line_vector)
{
linetablesize = sizeof (struct linetable) +
subfile->line_vector->nitems * sizeof (struct linetable_entry);
/* Like the pending blocks, the line table may be
scrambled in reordered executables. Sort it if
OBJF_REORDERED is true. */
if (objfile->flags & OBJF_REORDERED)
qsort (subfile->line_vector->item,
subfile->line_vector->nitems,
sizeof (struct linetable_entry), compare_line_numbers);
}
/* Allocate a symbol table if necessary. */
if (subfile->symtab == NULL)
subfile->symtab = allocate_symtab (subfile->name, objfile);
symtab = subfile->symtab;
/* Fill in its components. */
symtab->blockvector = blockvector;
symtab->macro_table = pending_macros;
if (subfile->line_vector)
{
/* Reallocate the line table on the symbol obstack. */
symtab->linetable = (struct linetable *)
obstack_alloc (&objfile->objfile_obstack, linetablesize);
memcpy (symtab->linetable, subfile->line_vector, linetablesize);
}
else
{
symtab->linetable = NULL;
}
symtab->block_line_section = section;
if (subfile->dirname)
{
/* Reallocate the dirname on the symbol obstack. */
symtab->dirname =
obstack_copy0 (&objfile->objfile_obstack,
subfile->dirname,
strlen (subfile->dirname));
}
else
{
symtab->dirname = NULL;
}
/* Use whatever language we have been using for this
subfile, not the one that was deduced in allocate_symtab
from the filename. We already did our own deducing when
we created the subfile, and we may have altered our
opinion of what language it is from things we found in
the symbols. */
symtab->language = subfile->language;
/* Save the debug format string (if any) in the symtab. */
symtab->debugformat = subfile->debugformat;
/* Similarly for the producer. */
symtab->producer = subfile->producer;
/* All symtabs for the main file and the subfiles share a
blockvector, so we need to clear primary for everything
but the main file. */
set_symtab_primary (symtab, 0);
}
/* The main source file is the primary symtab. */
gdb_assert (main_subfile->symtab != NULL);
symtab = main_subfile->symtab;
set_symtab_primary (symtab, 1);
{
struct block *b = BLOCKVECTOR_BLOCK (symtab->blockvector, GLOBAL_BLOCK);
set_block_symtab (b, symtab);
}
/* Default any symbols without a specified symtab to the primary symtab. */
{
int block_i;
for (block_i = 0; block_i < BLOCKVECTOR_NBLOCKS (blockvector); block_i++)
{
struct block *block = BLOCKVECTOR_BLOCK (blockvector, block_i);
struct symbol *sym;
struct dict_iterator iter;
/* Inlined functions may have symbols not in the global or
static symbol lists. */
if (BLOCK_FUNCTION (block) != NULL)
if (SYMBOL_SYMTAB (BLOCK_FUNCTION (block)) == NULL)
SYMBOL_SYMTAB (BLOCK_FUNCTION (block)) = symtab;
/* Note that we only want to fix up symbols from the local
blocks, not blocks coming from included symtabs. That is why
we use ALL_DICT_SYMBOLS here and not ALL_BLOCK_SYMBOLS. */
ALL_DICT_SYMBOLS (BLOCK_DICT (block), iter, sym)
if (SYMBOL_SYMTAB (sym) == NULL)
SYMBOL_SYMTAB (sym) = symtab;
}
}
return symtab;
}
/* Implementation of the second part of end_symtab. Pass STATIC_BLOCK
as value returned by end_symtab_get_static_block.
@ -1120,204 +1324,22 @@ end_symtab_from_static_block (struct block *static_block,
struct objfile *objfile, int section,
int expandable)
{
struct symtab *symtab = NULL;
struct blockvector *blockvector;
struct subfile *subfile;
struct subfile *nextsub;
struct symtab *s;
if (static_block == NULL)
{
/* Ignore symtabs that have no functions with real debugging info. */
blockvector = NULL;
end_symtab_without_blockvector (objfile);
s = NULL;
}
else
{
CORE_ADDR end_addr = BLOCK_END (static_block);
/* Define after STATIC_BLOCK also GLOBAL_BLOCK, and build the
blockvector. */
finish_block_internal (NULL, &global_symbols, NULL,
last_source_start_addr, end_addr, objfile,
1, expandable);
blockvector = make_blockvector (objfile);
}
/* Read the line table if it has to be read separately.
This is only used by xcoffread.c. */
if (objfile->sf->sym_read_linetable != NULL)
objfile->sf->sym_read_linetable (objfile);
/* Handle the case where the debug info specifies a different path
for the main source file. It can cause us to lose track of its
line number information. */
watch_main_source_file_lossage ();
/* Now create the symtab objects proper, one for each subfile. */
/* (The main file is the last one on the chain.) */
for (subfile = subfiles; subfile; subfile = nextsub)
{
int linetablesize = 0;
symtab = NULL;
/* If we have blocks of symbols, make a symtab. Otherwise, just
ignore this file and any line number info in it. */
if (blockvector)
{
if (subfile->line_vector)
{
linetablesize = sizeof (struct linetable) +
subfile->line_vector->nitems * sizeof (struct linetable_entry);
/* Like the pending blocks, the line table may be
scrambled in reordered executables. Sort it if
OBJF_REORDERED is true. */
if (objfile->flags & OBJF_REORDERED)
qsort (subfile->line_vector->item,
subfile->line_vector->nitems,
sizeof (struct linetable_entry), compare_line_numbers);
}
/* Now, allocate a symbol table. */
if (subfile->symtab == NULL)
symtab = allocate_symtab (subfile->name, objfile);
else
symtab = subfile->symtab;
/* Fill in its components. */
symtab->blockvector = blockvector;
symtab->macro_table = pending_macros;
if (subfile->line_vector)
{
/* Reallocate the line table on the symbol obstack. */
symtab->linetable = (struct linetable *)
obstack_alloc (&objfile->objfile_obstack, linetablesize);
memcpy (symtab->linetable, subfile->line_vector, linetablesize);
}
else
{
symtab->linetable = NULL;
}
symtab->block_line_section = section;
if (subfile->dirname)
{
/* Reallocate the dirname on the symbol obstack. */
symtab->dirname =
obstack_copy0 (&objfile->objfile_obstack,
subfile->dirname,
strlen (subfile->dirname));
}
else
{
symtab->dirname = NULL;
}
/* Use whatever language we have been using for this
subfile, not the one that was deduced in allocate_symtab
from the filename. We already did our own deducing when
we created the subfile, and we may have altered our
opinion of what language it is from things we found in
the symbols. */
symtab->language = subfile->language;
/* Save the debug format string (if any) in the symtab. */
symtab->debugformat = subfile->debugformat;
/* Similarly for the producer. */
symtab->producer = subfile->producer;
/* All symtabs for the main file and the subfiles share a
blockvector, so we need to clear primary for everything
but the main file. */
set_symtab_primary (symtab, 0);
}
else
{
if (subfile->symtab)
{
/* Since we are ignoring that subfile, we also need
to unlink the associated empty symtab that we created.
Otherwise, we can run into trouble because various parts
such as the block-vector are uninitialized whereas
the rest of the code assumes that they are.
We can only unlink the symtab because it was allocated
on the objfile obstack. */
struct symtab *s;
if (objfile->symtabs == subfile->symtab)
objfile->symtabs = objfile->symtabs->next;
else
ALL_OBJFILE_SYMTABS (objfile, s)
if (s->next == subfile->symtab)
{
s->next = s->next->next;
break;
}
subfile->symtab = NULL;
}
}
if (subfile->name != NULL)
{
xfree ((void *) subfile->name);
}
if (subfile->dirname != NULL)
{
xfree ((void *) subfile->dirname);
}
if (subfile->line_vector != NULL)
{
xfree ((void *) subfile->line_vector);
}
nextsub = subfile->next;
xfree ((void *) subfile);
}
/* Set this for the main source file. */
if (symtab)
{
set_symtab_primary (symtab, 1);
if (symtab->blockvector)
{
struct block *b = BLOCKVECTOR_BLOCK (symtab->blockvector,
GLOBAL_BLOCK);
set_block_symtab (b, symtab);
}
}
/* Default any symbols without a specified symtab to the primary
symtab. */
if (blockvector)
{
int block_i;
for (block_i = 0; block_i < BLOCKVECTOR_NBLOCKS (blockvector); block_i++)
{
struct block *block = BLOCKVECTOR_BLOCK (blockvector, block_i);
struct symbol *sym;
struct dict_iterator iter;
/* Inlined functions may have symbols not in the global or
static symbol lists. */
if (BLOCK_FUNCTION (block) != NULL)
if (SYMBOL_SYMTAB (BLOCK_FUNCTION (block)) == NULL)
SYMBOL_SYMTAB (BLOCK_FUNCTION (block)) = symtab;
/* Note that we only want to fix up symbols from the local
blocks, not blocks coming from included symtabs. That is why
we use ALL_DICT_SYMBOLS here and not ALL_BLOCK_SYMBOLS. */
ALL_DICT_SYMBOLS (BLOCK_DICT (block), iter, sym)
if (SYMBOL_SYMTAB (sym) == NULL)
SYMBOL_SYMTAB (sym) = symtab;
}
s = end_symtab_with_blockvector (static_block, objfile, section,
expandable);
}
reset_symtab_globals ();
return symtab;
return s;
}
/* Finish the symbol definitions for one main source file, close off