gdb/symtab: Eliminate deferred_entry

Currently cooked_index entry creation is either:
- done immediately if the parent_entry is known, or
- deferred if the parent_entry is not yet known, and done later while
  resolving the deferred entries.

Instead, create all cooked_index entries immediately, and keep track of which
entries have a parent_entry that needs resolving later using the new
IS_PARENT_DEFERRED flag.

Tested on x86_64-linux.

Approved-By: Tom Tromey <tom@tromey.com>

1 files changed, 46 insertions, 7 deletions

diff --git a/gdb/dwarf2/cooked-index.h b/gdb/dwarf2/cooked-index.h
index fa0807a..4c3b290 100644
--- a/gdb/dwarf2/cooked-index.h
+++ b/gdb/dwarf2/cooked-index.h
@@ -48,6 +48,7 @@
 struct dwarf2_per_cu_data;
 struct dwarf2_per_bfd;
 struct index_cache_store_context;
+struct cooked_index_entry;
 
 /* Flags that describe an entry in the index.  */
 enum cooked_index_flag_enum : unsigned char
@@ -63,9 +64,30 @@ enum cooked_index_flag_enum : unsigned char
   /* True if this entry is just for the declaration of a type, not the
      definition.  */
   IS_TYPE_DECLARATION = 16,
+  /* True is parent_entry.deferred has a value rather than parent_entry
+     .resolved.  */
+  IS_PARENT_DEFERRED = 32,
 };
 DEF_ENUM_FLAGS_TYPE (enum cooked_index_flag_enum, cooked_index_flag);
 
+/* Type representing either a resolved or deferred cooked_index_entry.  */
+
+union cooked_index_entry_ref
+{
+  cooked_index_entry_ref (CORE_ADDR deferred_)
+  {
+    deferred = deferred_;
+  }
+
+  cooked_index_entry_ref (const cooked_index_entry *resolved_)
+  {
+    resolved = resolved_;
+  }
+
+  const cooked_index_entry *resolved;
+  CORE_ADDR deferred;
+};
+
 /* Return a string representation of FLAGS.  */
 
 std::string to_string (cooked_index_flag flags);
@@ -88,7 +110,7 @@ struct cooked_index_entry : public allocate_on_obstack
 {
   cooked_index_entry (sect_offset die_offset_, enum dwarf_tag tag_,
 		      cooked_index_flag flags_, const char *name_,
-		      const cooked_index_entry *parent_entry_,
+		      cooked_index_entry_ref parent_entry_,
 		      dwarf2_per_cu_data *per_cu_)
     : name (name_),
       tag (tag_),
@@ -223,13 +245,30 @@ struct cooked_index_entry : public allocate_on_obstack
   /* Set parent entry to PARENT.  */
   void set_parent (const cooked_index_entry *parent)
   {
-    m_parent_entry = parent;
+    gdb_assert ((flags & IS_PARENT_DEFERRED) == 0);
+    m_parent_entry.resolved = parent;
+  }
+
+  /* Resolve deferred parent entry to PARENT.  */
+  void resolve_parent (const cooked_index_entry *parent)
+  {
+    gdb_assert ((flags & IS_PARENT_DEFERRED) != 0);
+    flags = flags & ~IS_PARENT_DEFERRED;
+    m_parent_entry.resolved = parent;
   }
 
   /* Return parent entry.  */
   const cooked_index_entry *get_parent () const
   {
-    return m_parent_entry;
+    gdb_assert ((flags & IS_PARENT_DEFERRED) == 0);
+    return m_parent_entry.resolved;
+  }
+
+  /* Return deferred parent entry.  */
+  CORE_ADDR get_deferred_parent () const
+  {
+    gdb_assert ((flags & IS_PARENT_DEFERRED) != 0);
+    return m_parent_entry.deferred;
   }
 
   /* The name as it appears in DWARF.  This always points into one of
@@ -260,7 +299,7 @@ private:
   /* The parent entry.  This is NULL for top-level entries.
      Otherwise, it points to the parent entry, such as a namespace or
      class.  */
-  const cooked_index_entry *m_parent_entry;
+  cooked_index_entry_ref m_parent_entry;
 };
 
 class cooked_index;
@@ -283,7 +322,7 @@ public:
   cooked_index_entry *add (sect_offset die_offset, enum dwarf_tag tag,
 			   cooked_index_flag flags,
 			   const char *name,
-			   const cooked_index_entry *parent_entry,
+			   cooked_index_entry_ref parent_entry,
 			   dwarf2_per_cu_data *per_cu);
 
   /* Install a new fixed addrmap from the given mutable addrmap.  */
@@ -334,7 +373,7 @@ private:
 			      enum dwarf_tag tag,
 			      cooked_index_flag flags,
 			      const char *name,
-			      const cooked_index_entry *parent_entry,
+			      cooked_index_entry_ref parent_entry,
 			      dwarf2_per_cu_data *per_cu)
   {
     return new (&m_storage) cooked_index_entry (die_offset, tag, flags,
@@ -399,7 +438,7 @@ public:
   cooked_index_entry *add (sect_offset die_offset, enum dwarf_tag tag,
 			   cooked_index_flag flags,
 			   const char *name,
-			   const cooked_index_entry *parent_entry,
+			   cooked_index_entry_ref parent_entry,
 			   dwarf2_per_cu_data *per_cu)
   {
     return m_index->add (die_offset, tag, flags, name, parent_entry, per_cu);