Add more styling to "disassemble"

This adds more styling to the disassemble command.  In particular,
addresses and function names in the disassembly are now styled.

This required fixing a small latent bug in set_output_style.  This
function always passed NULL to emit_style_escape; but when writing to
a file other than gdb_stdout, it should emit the style escape
directly.  (FWIW this is another argument for better integrating the
pager with ui_file and getting rid of this entire layer.)

gdb/ChangeLog
2019-08-06  Tom Tromey  <tom@tromey.com>

	* utils.c (set_output_style): Sometimes pass stream to
	emit_style_escape.
	* ui-out.h (class ui_out) <can_emit_style_escape>: Declare.
	* record-btrace.c (btrace_insn_history): Update.
	* mi/mi-out.h (class mi_ui_out) <can_emit_style_escape>: New
	method.
	* disasm.h (gdb_pretty_print_disassembler): Add uiout parameter.
	Update initializers.
	<m_uiout>: New field.
	<m_di>: Move lower.
	* disasm.c (gdb_pretty_print_disassembler::pretty_print_insn):
	Remove "uiout" parameter.
	(dump_insns): Update.
	* cli-out.h (class cli_ui_out) <can_emit_style_escape>: Declare.
	* cli-out.c (cli_ui_out::can_emit_style_escape): New method.

gdb/testsuite/ChangeLog
2019-08-06  Tom Tromey  <tom@tromey.com>

	* gdb.base/style.exp: Add disassemble test.
	* gdb.base/style.c (some_called_function): New function.
	(main): Use it.

1 files changed, 13 insertions, 7 deletions

diff --git a/gdb/disasm.h b/gdb/disasm.h
index a9cfb21..5c1b30b 100644
--- a/gdb/disasm.h
+++ b/gdb/disasm.h
@@ -112,26 +112,32 @@ extern int gdb_print_insn (struct gdbarch *gdbarch, CORE_ADDR memaddr,
 class gdb_pretty_print_disassembler
 {
 public:
-  explicit gdb_pretty_print_disassembler (struct gdbarch *gdbarch)
-    : m_di (gdbarch, &m_insn_stb)
+  explicit gdb_pretty_print_disassembler (struct gdbarch *gdbarch,
+					  struct ui_out *uiout)
+    : m_uiout (uiout),
+      m_insn_stb (uiout->can_emit_style_escape ()),
+      m_di (gdbarch, &m_insn_stb)
   {}
 
-  /* Prints the instruction INSN into UIOUT and returns the length of
-     the printed instruction in bytes.  */
-  int pretty_print_insn (struct ui_out *uiout, const struct disasm_insn *insn,
+  /* Prints the instruction INSN into the saved ui_out and returns the
+     length of the printed instruction in bytes.  */
+  int pretty_print_insn (const struct disasm_insn *insn,
 			 gdb_disassembly_flags flags);
 
 private:
   /* Returns the architecture used for disassembling.  */
   struct gdbarch *arch () { return m_di.arch (); }
 
-  /* The disassembler used for instruction printing.  */
-  gdb_disassembler m_di;
+  /* The ui_out that is used by pretty_print_insn.  */
+  struct ui_out *m_uiout;
 
   /* The buffer used to build the instruction string.  The
      disassembler is initialized with this stream.  */
   string_file m_insn_stb;
 
+  /* The disassembler used for instruction printing.  */
+  gdb_disassembler m_di;
+
   /* The buffer used to build the raw opcodes string.  */
   string_file m_opcode_stb;
 };