Re: [5/10] add notion of included symtabs

Tom Tromey
2012-05-10T20:04:17Z

>>>>> "Tom" == Tom Tromey <tromey@redhat.com> writes:

Tom> This patch changes symtabs to have a notion of "included" symtabs.

Here is the version I am checking in.

This takes Jan's comment into account, and it also adds
get_block_symtab, which was removed from the previous patch.

Tom

2012-05-10 Tom Tromey <tromey@redhat.com>

* symtab.h (struct symtab) <includes, user>: New fields.
* block.h (struct block_iterator) <d, idx, which>: New fields.
* block.c (initialize_block_iterator, find_iterator_symtab)
(block_iterator_step, block_iter_name_step)
(block_iter_match_step): New functions.
(block_iterator_first, block_iterator_next)
(block_iter_name_first, block_iter_name_next)
(block_iter_match_first, block_iter_match_next): Rewrite.
(get_block_symtab): New function.

Index: block.c
===================================================================
RCS file: /cvs/src/src/gdb/block.c,v
retrieving revision 1.29
diff -u -r1.29 block.c
--- block.c 10 May 2012 19:59:12 -0000 1.29
+++ block.c 10 May 2012 20:02:50 -0000
@@ -393,15 +393,138 @@
gb->symtab = symtab;
}

+/* Return the symtab of the global block. */
+
+static struct symtab *
+get_block_symtab (const struct block *block)
+{
+ struct global_block *gb;
+
+ gdb_assert (BLOCK_SUPERBLOCK (block) == NULL);
+ gb = (struct global_block *) block;
+ gdb_assert (gb->symtab != NULL);
+ return gb->symtab;
+}
+
\f

+/* Initialize a block iterator, either to iterate over a single block,
+ or, for static and global blocks, all the included symtabs as
+ well. */
+
+static void
+initialize_block_iterator (const struct block *block,
+ struct block_iterator *iter)
+{
+ enum block_enum which;
+ struct symtab *symtab;
+
+ iter->idx = -1;
+
+ if (BLOCK_SUPERBLOCK (block) == NULL)
+ {
+ which = GLOBAL_BLOCK;
+ symtab = get_block_symtab (block);
+ }
+ else if (BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) == NULL)
+ {
+ which = STATIC_BLOCK;
+ symtab = get_block_symtab (BLOCK_SUPERBLOCK (block));
+ }
+ else
+ {
+ iter->d.block = block;
+ /* A signal value meaning that we're iterating over a single
+ block. */
+ iter->which = FIRST_LOCAL_BLOCK;
+ return;
+ }
+
+ /* If this is an included symtab, find the canonical includer and
+ use it instead. */
+ while (symtab->user != NULL)
+ symtab = symtab->user;
+
+ /* Putting this check here simplifies the logic of the iterator
+ functions. If there are no included symtabs, we only need to
+ search a single block, so we might as well just do that
+ directly. */
+ if (symtab->includes == NULL)
+ {
+ iter->d.block = block;
+ /* A signal value meaning that we're iterating over a single
+ block. */
+ iter->which = FIRST_LOCAL_BLOCK;
+ }
+ else
+ {
+ iter->d.symtab = symtab;
+ iter->which = which;
+ }
+}
+
+/* A helper function that finds the current symtab over whose static
+ or global block we should iterate. */
+
+static struct symtab *
+find_iterator_symtab (struct block_iterator *iterator)
+{
+ if (iterator->idx == -1)
+ return iterator->d.symtab;
+ return iterator->d.symtab->includes[iterator->idx];
+}
+
+/* Perform a single step for a plain block iterator, iterating across
+ symbol tables as needed. Returns the next symbol, or NULL when
+ iteration is complete. */
+
+static struct symbol *
+block_iterator_step (struct block_iterator *iterator, int first)
+{
+ struct symbol *sym;
+
+ gdb_assert (iterator->which != FIRST_LOCAL_BLOCK);
+
+ while (1)
+ {
+ if (first)
+ {
+ struct symtab *symtab = find_iterator_symtab (iterator);
+ const struct block *block;
+
+ /* Iteration is complete. */
+ if (symtab == NULL)
+ return NULL;
+
+ block = BLOCKVECTOR_BLOCK (BLOCKVECTOR (symtab), iterator->which);
+ sym = dict_iterator_first (BLOCK_DICT (block), &iterator->dict_iter);
+ }
+ else
+ sym = dict_iterator_next (&iterator->dict_iter);
+
+ if (sym != NULL)
+ return sym;
+
+ /* We have finished iterating the appropriate block of one
+ symtab. Now advance to the next symtab and begin iteration
+ there. */
+ ++iterator->idx;
+ first = 1;
+ }
+}
+
/* See block.h. */

struct symbol *
block_iterator_first (const struct block *block,
struct block_iterator *iterator)
{
- return dict_iterator_first (block->dict, &iterator->dict_iter);
+ initialize_block_iterator (block, iterator);
+
+ if (iterator->which == FIRST_LOCAL_BLOCK)
+ return dict_iterator_first (block->dict, &iterator->dict_iter);
+
+ return block_iterator_step (iterator, 1);
}

/* See block.h. */
@@ -409,7 +532,51 @@
struct symbol *
block_iterator_next (struct block_iterator *iterator)
{
- return dict_iterator_next (&iterator->dict_iter);
+ if (iterator->which == FIRST_LOCAL_BLOCK)
+ return dict_iterator_next (&iterator->dict_iter);
+
+ return block_iterator_step (iterator, 0);
+}
+
+/* Perform a single step for a "name" block iterator, iterating across
+ symbol tables as needed. Returns the next symbol, or NULL when
+ iteration is complete. */
+
+static struct symbol *
+block_iter_name_step (struct block_iterator *iterator, const char *name,
+ int first)
+{
+ struct symbol *sym;
+
+ gdb_assert (iterator->which != FIRST_LOCAL_BLOCK);
+
+ while (1)
+ {
+ if (first)
+ {
+ struct symtab *symtab = find_iterator_symtab (iterator);
+ const struct block *block;
+
+ /* Iteration is complete. */
+ if (symtab == NULL)
+ return NULL;
+
+ block = BLOCKVECTOR_BLOCK (BLOCKVECTOR (symtab), iterator->which);
+ sym = dict_iter_name_first (BLOCK_DICT (block), name,
+ &iterator->dict_iter);
+ }
+ else
+ sym = dict_iter_name_next (name, &iterator->dict_iter);
+
+ if (sym != NULL)
+ return sym;
+
+ /* We have finished iterating the appropriate block of one
+ symtab. Now advance to the next symtab and begin iteration
+ there. */
+ ++iterator->idx;
+ first = 1;
+ }
}

/* See block.h. */
@@ -419,7 +586,12 @@
const char *name,
struct block_iterator *iterator)
{
- return dict_iter_name_first (block->dict, name, &iterator->dict_iter);
+ initialize_block_iterator (block, iterator);
+
+ if (iterator->which == FIRST_LOCAL_BLOCK)
+ return dict_iter_name_first (block->dict, name, &iterator->dict_iter);
+
+ return block_iter_name_step (iterator, name, 1);
}

/* See block.h. */
@@ -427,7 +599,53 @@
struct symbol *
block_iter_name_next (const char *name, struct block_iterator *iterator)
{
- return dict_iter_name_next (name, &iterator->dict_iter);
+ if (iterator->which == FIRST_LOCAL_BLOCK)
+ return dict_iter_name_next (name, &iterator->dict_iter);
+
+ return block_iter_name_step (iterator, name, 0);
+}
+
+/* Perform a single step for a "match" block iterator, iterating
+ across symbol tables as needed. Returns the next symbol, or NULL
+ when iteration is complete. */
+
+static struct symbol *
+block_iter_match_step (struct block_iterator *iterator,
+ const char *name,
+ symbol_compare_ftype *compare,
+ int first)
+{
+ struct symbol *sym;
+
+ gdb_assert (iterator->which != FIRST_LOCAL_BLOCK);
+
+ while (1)
+ {
+ if (first)
+ {
+ struct symtab *symtab = find_iterator_symtab (iterator);
+ const struct block *block;
+
+ /* Iteration is complete. */
+ if (symtab == NULL)
+ return NULL;
+
+ block = BLOCKVECTOR_BLOCK (BLOCKVECTOR (symtab), iterator->which);
+ sym = dict_iter_match_first (BLOCK_DICT (block), name,
+ compare, &iterator->dict_iter);
+ }
+ else
+ sym = dict_iter_match_next (name, compare, &iterator->dict_iter);
+
+ if (sym != NULL)
+ return sym;
+
+ /* We have finished iterating the appropriate block of one
+ symtab. Now advance to the next symtab and begin iteration
+ there. */
+ ++iterator->idx;
+ first = 1;
+ }
}

/* See block.h. */
@@ -438,8 +656,13 @@
symbol_compare_ftype *compare,
struct block_iterator *iterator)
{
- return dict_iter_match_first (block->dict, name, compare,
- &iterator->dict_iter);
+ initialize_block_iterator (block, iterator);
+
+ if (iterator->which == FIRST_LOCAL_BLOCK)
+ return dict_iter_match_first (block->dict, name, compare,
+ &iterator->dict_iter);
+
+ return block_iter_match_step (iterator, name, compare, 1);
}

/* See block.h. */
@@ -449,5 +672,8 @@
symbol_compare_ftype *compare,
struct block_iterator *iterator)
{
- return dict_iter_match_next (name, compare, &iterator->dict_iter);
+ if (iterator->which == FIRST_LOCAL_BLOCK)
+ return dict_iter_match_next (name, compare, &iterator->dict_iter);
+
+ return block_iter_match_step (iterator, name, compare, 0);
}
Index: block.h
===================================================================
RCS file: /cvs/src/src/gdb/block.h,v
retrieving revision 1.28
diff -u -r1.28 block.h
--- block.h 10 May 2012 19:59:12 -0000 1.28
+++ block.h 10 May 2012 20:02:50 -0000
@@ -186,6 +186,28 @@

struct block_iterator
{
+ /* If we're iterating over a single block, this holds the block.
+ Otherwise, it holds the canonical symtab. */
+
+ union
+ {
+ struct symtab *symtab;
+ const struct block *block;
+ } d;
+
+ /* If we're iterating over a single block, this is always -1.
+ Otherwise, it holds the index of the current "included" symtab in
+ the canonical symtab (that is, d.symtab->includes[idx]), with -1
+ meaning the canonical symtab itself. */
+
+ int idx;
+
+ /* Which block, either static or global, to iterate over. If this
+ is FIRST_LOCAL_BLOCK, then we are iterating over a single block.
+ This is used to select which field of 'd' is in use. */
+
+ enum block_enum which;
+
/* The underlying dictionary iterator. */

struct dict_iterator dict_iter;
Index: symtab.h
===================================================================
RCS file: /cvs/src/src/gdb/symtab.h,v
retrieving revision 1.205
diff -u -r1.205 symtab.h
--- symtab.h 27 Apr 2012 20:47:56 -0000 1.205
+++ symtab.h 10 May 2012 20:02:51 -0000
@@ -833,6 +833,23 @@
/* struct call_site entries for this compilation unit or NULL. */

htab_t call_site_htab;
+
+ /* If non-NULL, then this points to a NULL-terminated vector of
+ included symbol tables. When searching the static or global
+ block of this symbol table, the corresponding block of all
+ included symbol tables will also be searched. Note that this
+ list must be flattened -- the symbol reader is responsible for
+ ensuring that this vector contains the transitive closure of all
+ included symbol tables. */
+
+ struct symtab **includes;
+
+ /* If this is an included symbol table, this points to one includer
+ of the table. This user is considered the canonical symbol table
+ containing this one. An included symbol table may itself be
+ included by another. */
+
+ struct symtab *user;
};

#define BLOCKVECTOR(symtab) (symtab)->blockvector