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, 11 insertions, 8 deletions

diff --git a/gdb/cp-valprint.c b/gdb/cp-valprint.c
index 530d8c5..e73b0e2 100644
--- a/gdb/cp-valprint.c
+++ b/gdb/cp-valprint.c
@@ -37,6 +37,7 @@
 #include "typeprint.h"
 #include "gdbsupport/byte-vector.h"
 #include "gdbarch.h"
+#include "cli/cli-style.h"
 
 static struct obstack dont_print_vb_obstack;
 static struct obstack dont_print_statmem_obstack;
@@ -170,7 +171,7 @@ cp_print_value_fields (struct type *type, struct type *real_type,
 
   /* If there are no data fields, skip this part */
   if (len == n_baseclasses || !len)
-    fprintf_filtered (stream, "<No data fields>");
+    fprintf_styled (stream, metadata_style.style (), "<No data fields>");
   else
     {
       size_t statmem_obstack_initial_size = 0;
@@ -268,7 +269,8 @@ cp_print_value_fields (struct type *type, struct type *real_type,
 	         byte order problems.  */
 	      if (TYPE_FIELD_IGNORE (type, i))
 		{
-		  fputs_filtered ("<optimized out or zero length>", stream);
+		  fputs_styled ("<optimized out or zero length>",
+				metadata_style.style (), stream);
 		}
 	      else if (value_bits_synthetic_pointer (val,
 						     TYPE_FIELD_BITPOS (type,
@@ -276,7 +278,8 @@ cp_print_value_fields (struct type *type, struct type *real_type,
 						     TYPE_FIELD_BITSIZE (type,
 									 i)))
 		{
-		  fputs_filtered (_("<synthetic pointer>"), stream);
+		  fputs_styled (_("<synthetic pointer>"),
+				metadata_style.style (), stream);
 		}
 	      else
 		{
@@ -292,8 +295,8 @@ cp_print_value_fields (struct type *type, struct type *real_type,
 	    {
 	      if (TYPE_FIELD_IGNORE (type, i))
 		{
-		  fputs_filtered ("<optimized out or zero length>",
-				  stream);
+		  fputs_styled ("<optimized out or zero length>",
+				metadata_style.style (), stream);
 		}
 	      else if (field_is_static (&TYPE_FIELD (type, i)))
 		{
@@ -307,9 +310,9 @@ cp_print_value_fields (struct type *type, struct type *real_type,
 		    }
 		  catch (const gdb_exception_error &ex)
 		    {
-		      fprintf_filtered (stream,
-					_("<error reading variable: %s>"),
-					ex.what ());
+		      fprintf_styled (stream, metadata_style.style (),
+				      _("<error reading variable: %s>"),
+				      ex.what ());
 		    }
 		}
 	      else if (i == vptr_fieldno && type == vptr_basetype)