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

[Tom Tromey <tromey at redhat dot com>]

>>>>> "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;
+}
+
 
 
+/* 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