[PATCH v2] Factor out the common code in lookup_{static,global}_symbol

["Christian Biesinger via gdb-patches" <gdb-patches at sourceware dot org>]

The two functions are extremely similar; this factors out their code into
a shared _internal function.

gdb/ChangeLog:

2019-08-02  Christian Biesinger  <cbiesinger@google.com>

	* symtab.c (lookup_static_symbol): Call the new function (and move
	it down to be next to lookup_global_symbol).
	(struct global_sym_lookup_data): Add block_enum member.
	(lookup_symbol_global_iterator_cb): Pass block_index instead of
	GLOBAL_BLOCK to lookup_symbol_in_objfile.
	(lookup_global_symbol_internal): New function.
	(lookup_global_symbol): Call new function.
---
 gdb/symtab.c | 82 ++++++++++++++++++++++++----------------------------
 1 file changed, 37 insertions(+), 45 deletions(-)

diff --git a/gdb/symtab.c b/gdb/symtab.c
index 87a0c8e4da..1a5a6bf20e 100644
--- a/gdb/symtab.c
+++ b/gdb/symtab.c
@@ -2566,44 +2566,6 @@ lookup_symbol_in_objfile (struct objfile *objfile, enum block_enum block_index,
   return result;
 }
 
-/* See symtab.h.  */
-
-struct block_symbol
-lookup_static_symbol (const char *name, const domain_enum domain)
-{
-  struct symbol_cache *cache = get_symbol_cache (current_program_space);
-  struct block_symbol result;
-  struct block_symbol_cache *bsc;
-  struct symbol_cache_slot *slot;
-
-  /* Lookup in STATIC_BLOCK is not current-objfile-dependent, so just pass
-     NULL for OBJFILE_CONTEXT.  */
-  result = symbol_cache_lookup (cache, NULL, STATIC_BLOCK, name, domain,
-				&bsc, &slot);
-  if (result.symbol != NULL)
-    {
-      if (SYMBOL_LOOKUP_FAILED_P (result))
-	return {};
-      return result;
-    }
-
-  for (objfile *objfile : current_program_space->objfiles ())
-    {
-      result = lookup_symbol_in_objfile (objfile, STATIC_BLOCK, name, domain);
-      if (result.symbol != NULL)
-	{
-	  /* Still pass NULL for OBJFILE_CONTEXT here.  */
-	  symbol_cache_mark_found (bsc, slot, NULL, result.symbol,
-				   result.block);
-	  return result;
-	}
-    }
-
-  /* Still pass NULL for OBJFILE_CONTEXT here.  */
-  symbol_cache_mark_not_found (bsc, slot, NULL, name, domain);
-  return {};
-}
-
 /* Private data to be used with lookup_symbol_global_iterator_cb.  */
 
 struct global_sym_lookup_data
@@ -2614,6 +2576,9 @@ struct global_sym_lookup_data
   /* The domain to use for our search.  */
   domain_enum domain;
 
+  /* The block index in which to search */
+  enum block_enum block_index;
+
   /* The field where the callback should store the symbol if found.
      It should be initialized to {NULL, NULL} before the search is started.  */
   struct block_symbol result;
@@ -2634,7 +2599,7 @@ lookup_symbol_global_iterator_cb (struct objfile *objfile,
   gdb_assert (data->result.symbol == NULL
 	      && data->result.block == NULL);
 
-  data->result = lookup_symbol_in_objfile (objfile, GLOBAL_BLOCK,
+  data->result = lookup_symbol_in_objfile (objfile, data->block_index,
 					   data->name, data->domain);
 
   /* If we found a match, tell the iterator to stop.  Otherwise,
@@ -2642,12 +2607,15 @@ lookup_symbol_global_iterator_cb (struct objfile *objfile,
   return (data->result.symbol != NULL);
 }
 
-/* See symtab.h.  */
+/* This function contains the common code of lookup_{global,static}_symbol.
+   BLOCK is only used if BLOCK_INDEX is GLOBAL_SCOPE, in which case it is
+   used to retrieve the objfile to start the lookup in.  */
 
-struct block_symbol
-lookup_global_symbol (const char *name,
-		      const struct block *block,
-		      const domain_enum domain)
+static struct block_symbol
+lookup_global_symbol_internal (const char *name,
+			       enum block_enum block_index,
+			       const struct block *block,
+			       const domain_enum domain)
 {
   struct symbol_cache *cache = get_symbol_cache (current_program_space);
   struct block_symbol result;
@@ -2656,11 +2624,14 @@ lookup_global_symbol (const char *name,
   struct block_symbol_cache *bsc;
   struct symbol_cache_slot *slot;
 
+  gdb_assert (block_index == GLOBAL_BLOCK || block_index == STATIC_BLOCK);
+  gdb_assert (block == nullptr || block_index == GLOBAL_BLOCK);
+
   objfile = lookup_objfile_from_block (block);
 
   /* First see if we can find the symbol in the cache.
      This works because we use the current objfile to qualify the lookup.  */
-  result = symbol_cache_lookup (cache, objfile, GLOBAL_BLOCK, name, domain,
+  result = symbol_cache_lookup (cache, objfile, block_index, name, domain,
 				&bsc, &slot);
   if (result.symbol != NULL)
     {
@@ -2678,6 +2649,7 @@ lookup_global_symbol (const char *name,
     {
       memset (&lookup_data, 0, sizeof (lookup_data));
       lookup_data.name = name;
+      lookup_data.block_index = block_index;
       lookup_data.domain = domain;
       gdbarch_iterate_over_objfiles_in_search_order
 	(objfile != NULL ? get_objfile_arch (objfile) : target_gdbarch (),
@@ -2693,6 +2665,26 @@ lookup_global_symbol (const char *name,
   return result;
 }
 
+/* See symtab.h.  */
+
+struct block_symbol
+lookup_static_symbol (const char *name, const domain_enum domain)
+{
+  /* TODO: Should static symbol lookup start with a block as well, so we can
+     prefer a static symbol in the current CU?  */
+  return lookup_global_symbol_internal (name, STATIC_BLOCK, nullptr, domain);
+}
+
+/* See symtab.h.  */
+
+struct block_symbol
+lookup_global_symbol (const char *name,
+		      const struct block *block,
+		      const domain_enum domain)
+{
+  return lookup_global_symbol_internal (name, GLOBAL_BLOCK, block, domain);
+}
+
 int
 symbol_matches_domain (enum language symbol_language,
 		       domain_enum symbol_domain,
-- 
2.22.0.770.g0f2c4a37fd-goog