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.

6 files changed, 15 insertions, 4 deletions

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index c303d80..9fb10b5 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,12 @@
+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.
+
 2018-05-31  Maciej W. Rozycki  <macro@mips.com>
 
 	* gdb.base/endian.exp: New test.
diff --git a/gdb/testsuite/gdb.base/maint.exp b/gdb/testsuite/gdb.base/maint.exp
index aefaeb0..92086ee 100644
--- a/gdb/testsuite/gdb.base/maint.exp
+++ b/gdb/testsuite/gdb.base/maint.exp
@@ -360,7 +360,7 @@ foreach { test_name command } $test_list {
 
 set msg "maint print type"
 gdb_test_multiple "maint print type argc" $msg {
-    -re "type node $hex\r\nname .int. \\($hex\\)\r\ntagname .<NULL>. \\($hex\\)\r\ncode $hex \\(TYPE_CODE_INT\\)\r\nlength \[24\]\r\nobjfile $hex\r\ntarget_type $hex\r\npointer_type $hex\r\nreference_type $hex\r\ntype_chain $hex\r\ninstance_flags $hex\r\nflags\r\nnfields 0 $hex\r\n$gdb_prompt $" {
+    -re "type node $hex\r\nname .int. \\($hex\\)\r\ncode $hex \\(TYPE_CODE_INT\\)\r\nlength \[24\]\r\nobjfile $hex\r\ntarget_type $hex\r\npointer_type $hex\r\nreference_type $hex\r\ntype_chain $hex\r\ninstance_flags $hex\r\nflags\r\nnfields 0 $hex\r\n$gdb_prompt $" {
         pass $msg
     }
 }
diff --git a/gdb/testsuite/gdb.cp/typeid.exp b/gdb/testsuite/gdb.cp/typeid.exp
index 4378dcb..1731b78 100644
--- a/gdb/testsuite/gdb.cp/typeid.exp
+++ b/gdb/testsuite/gdb.cp/typeid.exp
@@ -27,7 +27,7 @@ proc do_typeid_tests {started} {
     global hex
 
     # We might see the standard type or gdb's internal type.
-    set type_re "(std::type_info|struct gdb_gnu_v3_type_info)"
+    set type_re "(std::type_info|gdb_gnu_v3_type_info)"
 
 
     foreach simple_var {i cp ccp ca b} {
diff --git a/gdb/testsuite/gdb.dwarf2/member-ptr-forwardref.exp b/gdb/testsuite/gdb.dwarf2/member-ptr-forwardref.exp
index 41eff92..31707bb 100644
--- a/gdb/testsuite/gdb.dwarf2/member-ptr-forwardref.exp
+++ b/gdb/testsuite/gdb.dwarf2/member-ptr-forwardref.exp
@@ -38,4 +38,5 @@ gdb_test "show cp-abi" {The currently selected C\+\+ ABI is "gnu-v3".*}
 
 gdb_load ${binfile}
 
+gdb_test_no_output "set language c++"
 gdb_test "ptype c" "type = struct C {\[\r\n \t\]*private:\[\r\n \t\]*int \\(C::\\*fp\\)\\(C \\*( const)?\\);\[\r\n \t\]*}"
diff --git a/gdb/testsuite/gdb.dwarf2/method-ptr.exp b/gdb/testsuite/gdb.dwarf2/method-ptr.exp
index 5a4f053..7fe755c 100644
--- a/gdb/testsuite/gdb.dwarf2/method-ptr.exp
+++ b/gdb/testsuite/gdb.dwarf2/method-ptr.exp
@@ -82,5 +82,6 @@ if { [prepare_for_testing "failed to prepare" ${testfile} \
     return -1
 }
 
+gdb_test_no_output "set language c++"
 gdb_test "ptype the_typedef" \
     "type = int \\(S::\\*\\)\\(S \\* const, float\\)"
diff --git a/gdb/testsuite/gdb.xml/tdesc-regs.exp b/gdb/testsuite/gdb.xml/tdesc-regs.exp
index bb7b9be..94d4007 100644
--- a/gdb/testsuite/gdb.xml/tdesc-regs.exp
+++ b/gdb/testsuite/gdb.xml/tdesc-regs.exp
@@ -179,7 +179,7 @@ gdb_test "ptype \$extrareg" "type = (int|long|long long)"
 gdb_test "ptype \$uintreg" "type = uint32_t"
 gdb_test "ptype \$vecreg" "type = int8_t __attribute__ \\(\\(vector_size\\(4\\)\\)\\)"
 gdb_test "ptype \$unionreg" \
-    "type = union {\r\n *v4int8 v4;\r\n *v2int16 v2;\r\n}"
+    "type = union vecint {\r\n *v4int8 v4;\r\n *v2int16 v2;\r\n}"
 gdb_test "ptype \$unionreg.v4" "type = int8_t __attribute__ \\(\\(vector_size\\(4\\)\\)\\)"
 gdb_test "ptype \$structreg" \
     "type = struct struct1 {\r\n *v4int8 v4;\r\n *v2int16 v2;\r\n}"
@@ -189,7 +189,7 @@ gdb_test "ptype \$bitfields" \
 gdb_test "ptype \$flags" \
     "type = flag flags {\r\n *bool X @0;\r\n *uint32_t Y @2;\r\n}"
 gdb_test "ptype \$mixed_flags" \
-    "type = flag mixed_flags {\r\n *bool A @0;\r\n *uint32_t B @1-3;\r\n *bool C @4;\r\n *uint32_t D @5;\r\n *uint32_t @6-7;\r\n *enum {yes = 1, no = 0, maybe = 2, so} Z @8-9;\r\n}"
+    "type = flag mixed_flags {\r\n *bool A @0;\r\n *uint32_t B @1-3;\r\n *bool C @4;\r\n *uint32_t D @5;\r\n *uint32_t @6-7;\r\n *enum Z_values {yes = 1, no = 0, maybe = 2, so} Z @8-9;\r\n}"
 # Reggroups should have at least general and the extra foo group
 gdb_test "maintenance print reggroups" \
     " Group\[ \t\]+Type\[ \t\]+\r\n.* general\[ \t\]+user\[ \t\]+\r\n.* foo\[ \t\]+user\[ \t\]+"