Remove TYPE_TAG_NAME

TYPE_TAG_NAME has been an occasional source of confusion and bugs.  It
seems to me that it is only useful for C and C++ -- but even there,
not so much, because at least with DWARF there doesn't seem to be any
way to wind up with a type where the name and the tag name are both
non-NULL and different.

So, this patch removes TYPE_TAG_NAME entirely.  This should save a
little memory, but more importantly, it simplifies this part of gdb.

A few minor test suite adjustments were needed.  In some situations
the new code does not yield identical output to the old code.

gdb/ChangeLog
2018-06-01  Tom Tromey  <tom@tromey.com>

	* valops.c (enum_constant_from_type, value_namespace_elt)
	(value_maybe_namespace_elt): Update.
	* valarith.c (find_size_for_pointer_math): Update.
	* target-descriptions.c (make_gdb_type): Update.
	* symmisc.c (print_symbol): Update.
	* stabsread.c (define_symbol, read_type)
	(complain_about_struct_wipeout, add_undefined_type)
	(cleanup_undefined_types_1): Update.
	* rust-lang.c (rust_tuple_type_p, rust_slice_type_p)
	(rust_range_type_p, val_print_struct, rust_print_struct_def)
	(rust_internal_print_type, rust_composite_type)
	(rust_evaluate_funcall, rust_evaluate_subexp)
	(rust_inclusive_range_type_p): Update.
	* python/py-type.c (typy_get_tag): Update.
	* p-typeprint.c (pascal_type_print_base): Update.
	* mdebugread.c (parse_symbol, parse_type): Update.
	* m2-typeprint.c (m2_long_set, m2_record_fields, m2_enum):
	Update.
	* guile/scm-type.c (gdbscm_type_tag): Update.
	* go-lang.c (sixg_string_p): Update.
	* gnu-v3-abi.c (build_gdb_vtable_type, build_std_type_info_type):
	Update.
	* gdbtypes.h (struct main_type) <tag_name>: Remove.
	(TYPE_TAG_NAME): Remove.
	* gdbtypes.c (type_name_no_tag): Simplify.
	(check_typedef, check_types_equal, recursive_dump_type)
	(copy_type_recursive, arch_composite_type): Update.
	* f-typeprint.c (f_type_print_base): Update.  Print "Type" prefix
	in summary mode when needed.
	* eval.c (evaluate_funcall): Update.
	* dwarf2read.c (fixup_go_packaging, read_structure_type)
	(process_structure_scope, read_enumeration_type)
	(read_namespace_type, read_module_type, determine_prefix): Update.
	* cp-support.c (inspect_type): Update.
	* coffread.c (process_coff_symbol, decode_base_type): Update.
	* c-varobj.c (c_is_path_expr_parent): Update.
	* c-typeprint.c (c_type_print_base_struct_union): Update.
	(c_type_print_base_1): Update.  Print struct/class/union/enum in
	summary when using C language.
	* ax-gdb.c (gen_struct_ref, gen_namespace_elt)
	(gen_maybe_namespace_elt): Update.
	* ada-lang.c (ada_type_name): Simplify.
	(empty_record, ada_template_to_fixed_record_type_1)
	(template_to_static_fixed_type)
	(to_record_with_fixed_variant_part, ada_check_typedef): Update.

gdb/testsuite/ChangeLog
2018-06-01  Tom Tromey  <tom@tromey.com>

	* gdb.xml/tdesc-regs.exp (load_description): Update expected
	results.
	* gdb.dwarf2/method-ptr.exp: Set language to C++.
	* gdb.dwarf2/member-ptr-forwardref.exp: Set language to C++.
	* gdb.cp/typeid.exp (do_typeid_tests): Update type_re.
	* gdb.base/maint.exp (maint_pass_if): Update.

1 files changed, 28 insertions, 29 deletions

diff --git a/gdb/rust-lang.c b/gdb/rust-lang.c
index ed03945..167f353 100644
--- a/gdb/rust-lang.c
+++ b/gdb/rust-lang.c
@@ -95,8 +95,8 @@ rust_tuple_type_p (struct type *type)
      nothing else in the debuginfo to distinguish a tuple from a
      struct.  */
   return (TYPE_CODE (type) == TYPE_CODE_STRUCT
-	  && TYPE_TAG_NAME (type) != NULL
-	  && TYPE_TAG_NAME (type)[0] == '(');
+	  && TYPE_NAME (type) != NULL
+	  && TYPE_NAME (type)[0] == '(');
 }
 
 /* Return true if all non-static fields of a structlike type are in a
@@ -143,9 +143,9 @@ static bool
 rust_slice_type_p (struct type *type)
 {
   return (TYPE_CODE (type) == TYPE_CODE_STRUCT
-	  && TYPE_TAG_NAME (type) != NULL
-	  && (strncmp (TYPE_TAG_NAME (type), "&[", 2) == 0
-	      || strcmp (TYPE_TAG_NAME (type), "&str") == 0));
+	  && TYPE_NAME (type) != NULL
+	  && (strncmp (TYPE_NAME (type), "&[", 2) == 0
+	      || strcmp (TYPE_NAME (type), "&str") == 0));
 }
 
 /* Return true if TYPE is a range type, otherwise false.  */
@@ -157,8 +157,8 @@ rust_range_type_p (struct type *type)
 
   if (TYPE_CODE (type) != TYPE_CODE_STRUCT
       || TYPE_NFIELDS (type) > 2
-      || TYPE_TAG_NAME (type) == NULL
-      || strstr (TYPE_TAG_NAME (type), "::Range") == NULL)
+      || TYPE_NAME (type) == NULL
+      || strstr (TYPE_NAME (type), "::Range") == NULL)
     return false;
 
   if (TYPE_NFIELDS (type) == 0)
@@ -187,8 +187,8 @@ rust_range_type_p (struct type *type)
 static bool
 rust_inclusive_range_type_p (struct type *type)
 {
-  return (strstr (TYPE_TAG_NAME (type), "::RangeInclusive") != NULL
-	  || strstr (TYPE_TAG_NAME (type), "::RangeToInclusive") != NULL);
+  return (strstr (TYPE_NAME (type), "::RangeInclusive") != NULL
+	  || strstr (TYPE_NAME (type), "::RangeToInclusive") != NULL);
 }
 
 /* Return true if TYPE seems to be the type "u8", otherwise false.  */
@@ -353,13 +353,13 @@ val_print_struct (struct type *type, int embedded_offset,
 
   if (!is_tuple)
     {
-      if (TYPE_TAG_NAME (type) != NULL)
-        fprintf_filtered (stream, "%s", TYPE_TAG_NAME (type));
+      if (TYPE_NAME (type) != NULL)
+        fprintf_filtered (stream, "%s", TYPE_NAME (type));
 
       if (TYPE_NFIELDS (type) == 0)
         return;
 
-      if (TYPE_TAG_NAME (type) != NULL)
+      if (TYPE_NAME (type) != NULL)
         fputs_filtered (" ", stream);
     }
 
@@ -628,7 +628,7 @@ rust_print_struct_def (struct type *type, const char *varstring,
   /* Print a tuple type simply.  */
   if (rust_tuple_type_p (type))
     {
-      fputs_filtered (TYPE_TAG_NAME (type), stream);
+      fputs_filtered (TYPE_NAME (type), stream);
       return;
     }
 
@@ -638,7 +638,7 @@ rust_print_struct_def (struct type *type, const char *varstring,
 
   /* Compute properties of TYPE here because, in the enum case, the
      rest of the code ends up looking only at the variant part.  */
-  const char *tagname = TYPE_TAG_NAME (type);
+  const char *tagname = TYPE_NAME (type);
   bool is_tuple_struct = rust_tuple_struct_type_p (type);
   bool is_tuple = rust_tuple_type_p (type);
   bool is_enum = rust_enum_p (type);
@@ -819,11 +819,11 @@ rust_internal_print_type (struct type *type, const char *varstring,
 	int i, len = 0;
 
 	fputs_filtered ("enum ", stream);
-	if (TYPE_TAG_NAME (type) != NULL)
+	if (TYPE_NAME (type) != NULL)
 	  {
-	    fputs_filtered (TYPE_TAG_NAME (type), stream);
+	    fputs_filtered (TYPE_NAME (type), stream);
 	    fputs_filtered (" ", stream);
-	    len = strlen (TYPE_TAG_NAME (type));
+	    len = strlen (TYPE_NAME (type));
 	  }
 	fputs_filtered ("{\n", stream);
 
@@ -834,7 +834,7 @@ rust_internal_print_type (struct type *type, const char *varstring,
 	    QUIT;
 
 	    if (len > 0
-		&& strncmp (name, TYPE_TAG_NAME (type), len) == 0
+		&& strncmp (name, TYPE_NAME (type), len) == 0
 		&& name[len] == ':'
 		&& name[len + 1] == ':')
 	      name += len + 2;
@@ -882,7 +882,6 @@ rust_composite_type (struct type *original,
 
   TYPE_CODE (result) = TYPE_CODE_STRUCT;
   TYPE_NAME (result) = name;
-  TYPE_TAG_NAME (result) = name;
 
   TYPE_NFIELDS (result) = nfields;
   TYPE_FIELDS (result)
@@ -1060,10 +1059,10 @@ rust_evaluate_funcall (struct expression *exp, int *pos, enum noside noside)
        && TYPE_CODE (type) != TYPE_CODE_ENUM)
       || rust_tuple_type_p (type))
     error (_("Method calls only supported on struct or enum types"));
-  if (TYPE_TAG_NAME (type) == NULL)
+  if (TYPE_NAME (type) == NULL)
     error (_("Method call on nameless type"));
 
-  std::string name = std::string (TYPE_TAG_NAME (type)) + "::" + method;
+  std::string name = std::string (TYPE_NAME (type)) + "::" + method;
 
   block = get_selected_block (0);
   sym = lookup_symbol (name.c_str (), block, VAR_DOMAIN, NULL);
@@ -1583,13 +1582,13 @@ rust_evaluate_subexp (struct type *expect_type, struct expression *exp,
 		if (outer_type != NULL)
 		  error(_("Cannot access field %d of variant %s::%s, "
 			  "there are only %d fields"),
-			field_number, TYPE_TAG_NAME (outer_type),
-			rust_last_path_segment (TYPE_TAG_NAME (type)),
+			field_number, TYPE_NAME (outer_type),
+			rust_last_path_segment (TYPE_NAME (type)),
 			nfields);
 		else
 		  error(_("Cannot access field %d of %s, "
 			  "there are only %d fields"),
-			field_number, TYPE_TAG_NAME (type), nfields);
+			field_number, TYPE_NAME (type), nfields);
 	      }
 
 	    /* Tuples are tuple structs too.  */
@@ -1597,13 +1596,13 @@ rust_evaluate_subexp (struct type *expect_type, struct expression *exp,
 	      {
 		if (outer_type != NULL)
 		  error(_("Variant %s::%s is not a tuple variant"),
-			TYPE_TAG_NAME (outer_type),
-			rust_last_path_segment (TYPE_TAG_NAME (type)));
+			TYPE_NAME (outer_type),
+			rust_last_path_segment (TYPE_NAME (type)));
 		else
 		  error(_("Attempting to access anonymous field %d "
 			  "of %s, which is not a tuple, tuple struct, or "
 			  "tuple-like variant"),
-		      field_number, TYPE_TAG_NAME (type));
+		      field_number, TYPE_NAME (type));
 	      }
 
 	    result = value_primitive_field (lhs, 0, field_number, type);
@@ -1645,7 +1644,7 @@ tuple structs, and tuple-like enum variants"));
 	    if (rust_tuple_type_p (type) || rust_tuple_struct_type_p (type))
 		error (_("Attempting to access named field foo of tuple "
 			 "variant %s::%s, which has only anonymous fields"),
-		       TYPE_TAG_NAME (outer_type),
+		       TYPE_NAME (outer_type),
 		       rust_last_path_segment (TYPE_NAME (type)));
 
 	    TRY
@@ -1656,7 +1655,7 @@ tuple structs, and tuple-like enum variants"));
 	    CATCH (except, RETURN_MASK_ERROR)
 	      {
 		error (_("Could not find field %s of struct variant %s::%s"),
-		       field_name, TYPE_TAG_NAME (outer_type),
+		       field_name, TYPE_NAME (outer_type),
 		       rust_last_path_segment (TYPE_NAME (type)));
 	      }
 	    END_CATCH