Introduce metadata style

This introduces a new "metadata" style and changes many places in gdb
to use it.  The idea here is to let the user distinguish gdb output
from output that (conceptually at least) comes directly from the
inferior.  The newly-styled category includes text that gdb
traditionally surrounds in "<...>", like "<unavailable>".

I only added a single test for this.  In many cases this output is
difficult to test.  Also, while developing this errors in the
implementation of the new printf formats showed up as regressions.

gdb/ChangeLog
2019-10-01  Tom Tromey  <tom@tromey.com>

	* p-lang.c (pascal_printstr): Use metadata style.
	* value.c (show_convenience): Use metadata style.
	* valprint.c (valprint_check_validity, val_print_optimized_out)
	(val_print_not_saved, val_print_unavailable)
	(val_print_invalid_address, generic_val_print, val_print)
	(value_check_printable, val_print_array_elements): Use metadata
	style.
	* ui-out.h (class ui_out) <field_fmt>: New overload.
	<do_field_fmt>: Add style parameter.
	* ui-out.c (ui_out::field_fmt): New overload.
	* typeprint.c (type_print_unknown_return_type)
	(val_print_not_allocated, val_print_not_associated): Use metadata
	style.
	* tui/tui-out.h (class tui_ui_out) <do_field_fmt>: Add style
	parameter.
	* tui/tui-out.c (tui_ui_out::do_field_fmt): Update.
	* tracepoint.c (tvariables_info_1): Use metadata style.
	* stack.c (print_frame_arg, print_frame_info, print_frame)
	(info_frame_command_core): Use metadata style.
	* skip.c (info_skip_command): Use metadata style.
	* rust-lang.c (rust_print_enum): Use metadata style.
	* python/py-prettyprint.c (print_stack_unless_memory_error): Use
	metadata style.
	* python/py-framefilter.c (py_print_single_arg): Use metadata
	style.
	* printcmd.c (do_one_display, print_variable_and_value): Use
	metadata style.
	* p-valprint.c (pascal_val_print)
	(pascal_object_print_value_fields): Use metadata style.
	* p-typeprint.c (pascal_type_print_base): Use metadata style.
	* mi/mi-out.h (class mi_ui_out) <do_field_fmt>: Add style
	parameter.
	* mi/mi-out.c (mi_ui_out::do_field_fmt): Update.
	* m2-valprint.c (m2_print_long_set): Use metadata style.
	* m2-typeprint.c (m2_print_type): Use metadata style.
	* infcmd.c (print_return_value_1): Use metadata style.
	* gnu-v3-abi.c (print_one_vtable): Use metadata style.
	* f-valprint.c (info_common_command_for_block): Use metadata
	style.
	* f-typeprint.c (f_type_print_base): Use metadata style.
	* expprint.c (print_subexp_standard): Use metadata style.
	* cp-valprint.c (cp_print_value_fields): Use metadata style.
	* cli/cli-style.h (class cli_style_option): Add constructor.
	(metadata_style): Declare.
	* cli/cli-style.c (metadata_style): New global.
	(_initialize_cli_style): Register metadata style.
	* cli-out.h (class cli_ui_out) <do_field_fmt>: Add style
	parameter.
	* cli-out.c (cli_ui_out::do_field_fmt): Update.
	* c-typeprint.c (c_type_print_base_struct_union)
	(c_type_print_base_1): Use metadata style.
	* breakpoint.c (watchpoint_value_print)
	(print_one_breakpoint_location): Use metadata style.
	* break-catch-syscall.c (print_one_catch_syscall): Use metadata
	style.
	* break-catch-sig.c (signal_catchpoint_print_one): Use metadata
	style.
	* ada-valprint.c (val_print_packed_array_elements, printstr)
	(print_field_values, ada_val_print_ref, ada_val_print): Use
	metadata style.
	* ada-typeprint.c (print_array_type, ada_print_type): Use metadata
	style.
	* ada-tasks.c (print_ada_task_info, info_task): Use metadata
	style.
	* ada-lang.c (user_select_syms): Use metadata style.

gdb/testsuite/ChangeLog
2019-10-01  Tom Tromey  <tom@tromey.com>

	* lib/gdb-utils.exp (style): Handle "metadata" argument.
	* gdb.base/style.exp: Add metadata style test.

1 files changed, 9 insertions, 6 deletions

diff --git a/gdb/ada-typeprint.c b/gdb/ada-typeprint.c
index 89a69e9bd44..c2461660ad4 100644
--- a/gdb/ada-typeprint.c
+++ b/gdb/ada-typeprint.c
@@ -393,7 +393,8 @@ print_array_type (struct type *type, struct ui_file *stream, int show,
 
   if (type == NULL)
     {
-      fprintf_filtered (stream, _("<undecipherable array type>"));
+      fprintf_styled (stream, metadata_style.style (),
+		      _("<undecipherable array type>"));
       return;
     }
 
@@ -838,7 +839,7 @@ ada_print_type (struct type *type0, const char *varstring,
       if (is_var_decl)
 	fprintf_filtered (stream, "%.*s: ",
 			  ada_name_prefix_len (varstring), varstring);
-      fprintf_filtered (stream, "<null type?>");
+      fprintf_styled (stream, metadata_style.style (), "<null type?>");
       return;
     }
 
@@ -894,8 +895,9 @@ ada_print_type (struct type *type0, const char *varstring,
 	    const char *name = ada_type_name (type);
 
 	    if (!ada_is_range_type_name (name))
-	      fprintf_filtered (stream, _("<%s-byte integer>"),
-				pulongest (TYPE_LENGTH (type)));
+	      fprintf_styled (stream, metadata_style.style (),
+			      _("<%s-byte integer>"),
+			      pulongest (TYPE_LENGTH (type)));
 	    else
 	      {
 		fprintf_filtered (stream, "range ");
@@ -916,8 +918,9 @@ ada_print_type (struct type *type0, const char *varstring,
 	  }
 	break;
       case TYPE_CODE_FLT:
-	fprintf_filtered (stream, _("<%s-byte float>"),
-			  pulongest (TYPE_LENGTH (type)));
+	fprintf_styled (stream, metadata_style.style (),
+			_("<%s-byte float>"),
+			pulongest (TYPE_LENGTH (type)));
 	break;
       case TYPE_CODE_ENUM:
 	if (show < 0)