Remove null_block_symbol

This removes null_block_symbol. It seemed simpler to me to change initializations and returns to use value initialization rather than null_block_symbol. This also fixes up a few spots where initialization was done piecemeal. gdb/ChangeLog 2019-03-24 Tom Tromey <tom@tromey.com> * ada-lang.c (standard_lookup): Simplify initialization. (ada_lookup_symbol_nonlocal): Simplify return. * solib-spu.c (spu_lookup_lib_symbol): Simplify return. * solib-darwin.c (darwin_lookup_lib_symbol): Simplify return. * solib-svr4.c (elf_lookup_lib_symbol): Simplify return. * rust-lang.c (rust_lookup_symbol_nonlocal): Simplify initialization. * solib.c (solib_global_lookup): Simplify. * symtab.c (null_block_symbol): Remove. (symbol_cache_lookup): Simplify returns. (lookup_language_this): Simplify returns. (lookup_symbol_aux): Simplify return. (lookup_local_symbol): Simplify returns. (lookup_global_symbol_from_objfile): Simplify return. (lookup_symbol_in_objfile_symtabs) (lookup_symbol_in_objfile_from_linkage_name): Simplify return. (lookup_symbol_via_quick_fns, lookup_symbol_in_static_block) (lookup_static_symbol, lookup_global_symbol): Simplify return. * cp-namespace.c (cp_lookup_bare_symbol) (cp_search_static_and_baseclasses, cp_lookup_symbol_via_imports) (cp_lookup_symbol_via_all_imports, cp_lookup_nested_symbol_1) (cp_lookup_nested_symbol): Don't use null_block_symbol. (cp_lookup_symbol_via_imports): Simplify initialization. (find_symbol_in_baseclass): Likewise. * symtab.h (null_block_symbol): Remove. * d-namespace.c (d_lookup_symbol): Don't use null_block_symbol. (d_lookup_nested_symbol, d_lookup_symbol_imports) (d_lookup_symbol_module): Likewise. (find_symbol_in_baseclass): Simplify initialization.
2025-01-27 02:14:04 +08:00 · 2019-03-22 16:53:12 -06:00 · 2019-03-22 16:53:12 -06:00 · 6640a367bf
commit 6640a367bf
parent a930ebcdf9
11 changed files with 71 additions and 55 deletions
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@ -1,3 +1,35 @@
+2019-03-24  Tom Tromey  <tom@tromey.com>
+
+	* ada-lang.c (standard_lookup): Simplify initialization.
+	(ada_lookup_symbol_nonlocal): Simplify return.
+	* solib-spu.c (spu_lookup_lib_symbol): Simplify return.
+	* solib-darwin.c (darwin_lookup_lib_symbol): Simplify return.
+	* solib-svr4.c (elf_lookup_lib_symbol): Simplify return.
+	* rust-lang.c (rust_lookup_symbol_nonlocal): Simplify
+	initialization.
+	* solib.c (solib_global_lookup): Simplify.
+	* symtab.c (null_block_symbol): Remove.
+	(symbol_cache_lookup): Simplify returns.
+	(lookup_language_this): Simplify returns.
+	(lookup_symbol_aux): Simplify return.
+	(lookup_local_symbol): Simplify returns.
+	(lookup_global_symbol_from_objfile): Simplify return.
+	(lookup_symbol_in_objfile_symtabs)
+	(lookup_symbol_in_objfile_from_linkage_name): Simplify return.
+	(lookup_symbol_via_quick_fns, lookup_symbol_in_static_block)
+	(lookup_static_symbol, lookup_global_symbol): Simplify return.
+	* cp-namespace.c (cp_lookup_bare_symbol)
+	(cp_search_static_and_baseclasses, cp_lookup_symbol_via_imports)
+	(cp_lookup_symbol_via_all_imports, cp_lookup_nested_symbol_1)
+	(cp_lookup_nested_symbol): Don't use null_block_symbol.
+	(cp_lookup_symbol_via_imports): Simplify initialization.
+	(find_symbol_in_baseclass): Likewise.
+	* symtab.h (null_block_symbol): Remove.
+	* d-namespace.c (d_lookup_symbol): Don't use null_block_symbol.
+	(d_lookup_nested_symbol, d_lookup_symbol_imports)
+	(d_lookup_symbol_module): Likewise.
+	(find_symbol_in_baseclass): Simplify initialization.
+
 2019-03-24  Tom Tromey  <tom@tromey.com>

 	* expression.h: Don't include symtab.h.
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@ -4758,7 +4758,7 @@ standard_lookup (const char *name, const struct block *block,
                 domain_enum domain)
 {
  /* Initialize it just to avoid a GCC false warning.  */
-  struct block_symbol sym = {NULL, NULL};
+  struct block_symbol sym = {};

  if (lookup_cached_symbol (name, domain, &sym.symbol, NULL))
    return sym.symbol;
@ -5918,7 +5918,7 @@ ada_lookup_symbol_nonlocal (const struct language_defn *langdef,
 	return sym;
    }

-  return (struct block_symbol) {NULL, NULL};
+  return {};
 }


--- a/gdb/cp-namespace.c
+++ b/gdb/cp-namespace.c
@ -217,7 +217,7 @@ cp_lookup_bare_symbol (const struct language_defn *langdef,
 	lang_this = lookup_language_this (langdef, block);

      if (lang_this.symbol == NULL)
-	return null_block_symbol;
+	return {};


      type = check_typedef (TYPE_TARGET_TYPE (SYMBOL_TYPE (lang_this.symbol)));
@ -225,7 +225,7 @@ cp_lookup_bare_symbol (const struct language_defn *langdef,
 	 This can happen for lambda functions compiled with clang++,
 	 which outputs no name for the container class.  */
      if (TYPE_NAME (type) == NULL)
-	return null_block_symbol;
+	return {};

      /* Look for symbol NAME in this class.  */
      sym = cp_lookup_nested_symbol (type, name, block, domain);
@ -252,7 +252,7 @@ cp_search_static_and_baseclasses (const char *name,
 {
  /* Check for malformed input.  */
  if (prefix_len + 2 > strlen (name) || name[prefix_len + 1] != ':')
-    return null_block_symbol;
+    return {};

  /* The class, namespace or function name is everything up to and
     including PREFIX_LEN.  */
@ -272,7 +272,7 @@ cp_search_static_and_baseclasses (const char *name,
  if (scope_sym.symbol == NULL)
    scope_sym = lookup_global_symbol (scope.c_str (), block, VAR_DOMAIN);
  if (scope_sym.symbol == NULL)
-    return null_block_symbol;
+    return {};

  struct type *scope_type = SYMBOL_TYPE (scope_sym.symbol);

@ -379,13 +379,10 @@ cp_lookup_symbol_via_imports (const char *scope,
 			      const int search_parents)
 {
  struct using_direct *current;
-  struct block_symbol sym;
+  struct block_symbol sym = {};
  int len;
  int directive_match;

-  sym.symbol = NULL;
-  sym.block = NULL;
-
  /* First, try to find the symbol in the given namespace if requested.  */
  if (search_scope_first)
    sym = cp_lookup_symbol_in_namespace (scope, name,
@ -476,7 +473,7 @@ cp_lookup_symbol_via_imports (const char *scope,
 	}
    }

-  return null_block_symbol;
+  return {};
 }

 /* Helper function that searches an array of symbols for one named NAME.  */
@ -621,7 +618,7 @@ cp_lookup_symbol_via_all_imports (const char *scope, const char *name,
      block = BLOCK_SUPERBLOCK (block);
    }

-  return null_block_symbol;
+  return {};
 }

 /* Searches for NAME in the current namespace, and by applying
@ -808,10 +805,7 @@ find_symbol_in_baseclass (struct type *parent_type, const char *name,
 			  int is_in_anonymous)
 {
  int i;
-  struct block_symbol sym;
-
-  sym.symbol = NULL;
-  sym.block = NULL;
+  struct block_symbol sym = {};

  for (i = 0; i < TYPE_N_BASECLASSES (parent_type); ++i)
    {
@ -902,7 +896,7 @@ cp_lookup_nested_symbol_1 (struct type *container_type,
 	return sym;
    }

-  return null_block_symbol;
+  return {};
 }

 /* Look up a symbol named NESTED_NAME that is nested inside the C++
@ -979,7 +973,7 @@ cp_lookup_nested_symbol (struct type *parent_type,
 			      "cp_lookup_nested_symbol (...) = NULL"
 			      " (func/method)\n");
 	}
-      return null_block_symbol;
+      return {};

    default:
      internal_error (__FILE__, __LINE__,
--- a/gdb/d-namespace.c
+++ b/gdb/d-namespace.c
@ -127,7 +127,7 @@ d_lookup_symbol (const struct language_defn *langdef,

 	  lang_this = lookup_language_this (language_def (language_d), block);
 	  if (lang_this.symbol == NULL)
-	    return null_block_symbol;
+	    return {};

 	  type = check_typedef (TYPE_TARGET_TYPE (SYMBOL_TYPE (lang_this.symbol)));
 	  classname = TYPE_NAME (type);
@ -147,7 +147,7 @@ d_lookup_symbol (const struct language_defn *langdef,
 	 more that can be done.  */
      class_sym = lookup_global_symbol (classname.c_str (), block, domain);
      if (class_sym.symbol == NULL)
-	return null_block_symbol;
+	return {};

      /* Look for a symbol named NESTED in this class.  */
      sym = d_lookup_nested_symbol (SYMBOL_TYPE (class_sym.symbol),
@ -246,12 +246,9 @@ static struct block_symbol
 find_symbol_in_baseclass (struct type *parent_type, const char *name,
 			  const struct block *block)
 {
-  struct block_symbol sym;
+  struct block_symbol sym = {};
  int i;

-  sym.symbol = NULL;
-  sym.block = NULL;
-
  for (i = 0; i < TYPE_N_BASECLASSES (parent_type); ++i)
    {
      struct type *base_type = TYPE_BASECLASS (parent_type, i);
@ -349,7 +346,7 @@ d_lookup_nested_symbol (struct type *parent_type,

    case TYPE_CODE_FUNC:
    case TYPE_CODE_METHOD:
-      return null_block_symbol;
+      return {};

    default:
      gdb_assert_not_reached ("called with non-aggregate type.");
@ -464,7 +461,7 @@ d_lookup_symbol_imports (const char *scope, const char *name,
 	}
    }

-  return null_block_symbol;
+  return {};
 }

 /* Searches for NAME in the current module, and by applying relevant
@ -496,7 +493,7 @@ d_lookup_symbol_module (const char *scope, const char *name,
      block = BLOCK_SUPERBLOCK (block);
    }

-  return null_block_symbol;
+  return {};
 }

 /* The D-specific version of name lookup for static and global names
--- a/gdb/rust-lang.c
+++ b/gdb/rust-lang.c
@ -2020,7 +2020,7 @@ rust_lookup_symbol_nonlocal (const struct language_defn *langdef,
 			     const struct block *block,
 			     const domain_enum domain)
 {
-  struct block_symbol result = {NULL, NULL};
+  struct block_symbol result = {};

  if (symbol_lookup_debug)
    {
--- a/gdb/solib-darwin.c
+++ b/gdb/solib-darwin.c
@ -653,7 +653,7 @@ darwin_lookup_lib_symbol (struct objfile *objfile,
 			  const char *name,
 			  const domain_enum domain)
 {
-  return (struct block_symbol) {NULL, NULL};
+  return {};
 }

 static gdb_bfd_ref_ptr
--- a/gdb/solib-spu.c
+++ b/gdb/solib-spu.c
@ -397,7 +397,7 @@ spu_lookup_lib_symbol (struct objfile *objfile,

  if (svr4_so_ops.lookup_lib_global_symbol != NULL)
    return svr4_so_ops.lookup_lib_global_symbol (objfile, name, domain);
-  return (struct block_symbol) {NULL, NULL};
+  return {};
 }

 /* Enable shared library breakpoint.  */
--- a/gdb/solib-svr4.c
+++ b/gdb/solib-svr4.c
@ -3204,7 +3204,7 @@ elf_lookup_lib_symbol (struct objfile *objfile,
    }

  if (abfd == NULL || scan_dyntag (DT_SYMBOLIC, abfd, NULL, NULL) != 1)
-    return (struct block_symbol) {NULL, NULL};
+    return {};

  return lookup_global_symbol_from_objfile (objfile, name, domain);
 }
--- a/gdb/solib.c
+++ b/gdb/solib.c
@ -1457,7 +1457,7 @@ solib_global_lookup (struct objfile *objfile,

  if (ops->lookup_lib_global_symbol != NULL)
    return ops->lookup_lib_global_symbol (objfile, name, domain);
-  return (struct block_symbol) {NULL, NULL};
+  return {};
 }

 /* Lookup the value for a specific symbol from dynamic symbol table.  Look
--- a/gdb/symtab.c
+++ b/gdb/symtab.c
@ -95,9 +95,6 @@ static struct block_symbol
  lookup_symbol_in_objfile (struct objfile *objfile, int block_index,
 			    const char *name, const domain_enum domain);

-/* See symtab.h.  */
-const struct block_symbol null_block_symbol = { NULL, NULL };
-
 /* Program space key for finding name and language of "main".  */

 static const struct program_space_data *main_progspace_key;
@ -1339,7 +1336,7 @@ symbol_cache_lookup (struct symbol_cache *cache,
    {
      *bsc_ptr = NULL;
      *slot_ptr = NULL;
-      return (struct block_symbol) {NULL, NULL};
+      return {};
    }

  hash = hash_symbol_entry (objfile_context, name, domain);
@ -1373,7 +1370,7 @@ symbol_cache_lookup (struct symbol_cache *cache,
 			  name, domain_name (domain));
    }
  ++bsc->misses;
-  return (struct block_symbol) {NULL, NULL};
+  return {};
 }

 /* Clear out SLOT.  */
@ -1938,7 +1935,7 @@ lookup_language_this (const struct language_defn *lang,
 		      const struct block *block)
 {
  if (lang->la_name_of_this == NULL || block == NULL)
-    return (struct block_symbol) {NULL, NULL};
+    return {};

  if (symbol_lookup_debug > 1)
    {
@ -1975,7 +1972,7 @@ lookup_language_this (const struct language_defn *lang,

  if (symbol_lookup_debug > 1)
    fprintf_unfiltered (gdb_stdlog, " = NULL\n");
-  return (struct block_symbol) {NULL, NULL};
+  return {};
 }

 /* Given TYPE, a structure/union,
@ -2102,7 +2099,7 @@ lookup_symbol_aux (const char *name, symbol_name_match_type match_type,
 		  fprintf_unfiltered (gdb_stdlog,
 				      "lookup_symbol_aux (...) = NULL\n");
 		}
-	      return (struct block_symbol) {NULL, NULL};
+	      return {};
 	    }
 	}
    }
@ -2152,7 +2149,7 @@ lookup_local_symbol (const char *name,
  /* Check if either no block is specified or it's a global block.  */

  if (static_block == NULL)
-    return (struct block_symbol) {NULL, NULL};
+    return {};

  while (block != static_block)
    {
@ -2177,7 +2174,7 @@ lookup_local_symbol (const char *name,

  /* We've reached the end of the function without finding a result.  */

-  return (struct block_symbol) {NULL, NULL};
+  return {};
 }

 /* See symtab.h.  */
@ -2262,7 +2259,7 @@ lookup_global_symbol_from_objfile (struct objfile *main_objfile,
 	return result;
    }

-  return (struct block_symbol) {NULL, NULL};
+  return {};
 }

 /* Check to see if the symbol is defined in one of the OBJFILE's
@ -2312,7 +2309,7 @@ lookup_symbol_in_objfile_symtabs (struct objfile *objfile, int block_index,

  if (symbol_lookup_debug > 1)
    fprintf_unfiltered (gdb_stdlog, " = NULL\n");
-  return (struct block_symbol) {NULL, NULL};
+  return {};
 }

 /* Wrapper around lookup_symbol_in_objfile_symtabs for search_symbols.
@ -2355,7 +2352,7 @@ lookup_symbol_in_objfile_from_linkage_name (struct objfile *objfile,
 	return result;
    }

-  return (struct block_symbol) {NULL, NULL};
+  return {};
 }

 /* A helper function that throws an exception when a symbol was found
@ -2388,7 +2385,7 @@ lookup_symbol_via_quick_fns (struct objfile *objfile, int block_index,
  struct block_symbol result;

  if (!objfile->sf)
-    return (struct block_symbol) {NULL, NULL};
+    return {};

  if (symbol_lookup_debug > 1)
    {
@ -2408,7 +2405,7 @@ lookup_symbol_via_quick_fns (struct objfile *objfile, int block_index,
 	  fprintf_unfiltered (gdb_stdlog,
 			      "lookup_symbol_via_quick_fns (...) = NULL\n");
 	}
-      return (struct block_symbol) {NULL, NULL};
+      return {};
    }

  bv = COMPUNIT_BLOCKVECTOR (cust);
@ -2512,7 +2509,7 @@ lookup_symbol_in_static_block (const char *name,
  struct symbol *sym;

  if (static_block == NULL)
-    return (struct block_symbol) {NULL, NULL};
+    return {};

  if (symbol_lookup_debug)
    {
@ -2605,7 +2602,7 @@ lookup_static_symbol (const char *name, const domain_enum domain)
  if (result.symbol != NULL)
    {
      if (SYMBOL_LOOKUP_FAILED_P (result))
-	return (struct block_symbol) {NULL, NULL};
+	return {};
      return result;
    }

@ -2623,7 +2620,7 @@ lookup_static_symbol (const char *name, const domain_enum domain)

  /* Still pass NULL for OBJFILE_CONTEXT here.  */
  symbol_cache_mark_not_found (bsc, slot, NULL, name, domain);
-  return (struct block_symbol) {NULL, NULL};
+  return {};
 }

 /* Private data to be used with lookup_symbol_global_iterator_cb.  */
@ -2687,7 +2684,7 @@ lookup_global_symbol (const char *name,
  if (result.symbol != NULL)
    {
      if (SYMBOL_LOOKUP_FAILED_P (result))
-	return (struct block_symbol) {NULL, NULL};
+	return {};
      return result;
    }

--- a/gdb/symtab.h
+++ b/gdb/symtab.h
@ -1159,10 +1159,6 @@ struct block_symbol

 extern const struct symbol_impl *symbol_impls;

-/* For convenience.  All fields are NULL.  This means "there is no
-   symbol".  */
-extern const struct block_symbol null_block_symbol;
-
 /* Note: There is no accessor macro for symbol.owner because it is
   "private".  */