Eliminate make_cleanup_ui_file_delete / make ui_file a class hierarchy

This patch starts from the desire to eliminate
make_cleanup_ui_file_delete, but then goes beyond.  It makes ui_file &
friends a real C++ class hierarchy, and switches temporary
ui_file-like objects to stack-based allocation.

- mem_fileopen -> string_file

mem_fileopen is replaced with a new string_file class that is treated
as a value class created on the stack.  This alone eliminates most
make_cleanup_ui_file_delete calls, and, simplifies code a whole lot
(diffstat shows around 1k loc dropped.)

string_file's internal buffer is a std::string, thus the "string" in
the name.  This simplifies the implementation much, compared to
mem_fileopen, which managed growing its internal buffer manually.

- ui_file_as_string, ui_file_strdup, ui_file_obsavestring all gone

The new string_file class has a string() method that provides direct
writable access to the internal std::string buffer.  This replaced
ui_file_as_string, which forced a copy of the same data the stream had
inside.  With direct access via a writable reference, we can instead
move the string out of the string_stream, avoiding deep string
copying.

Related, ui_file_xstrdup calls are replaced with xstrdup'ping the
stream's string, and ui_file_obsavestring is replaced by
obstack_copy0.

With all those out of the way, getting rid of the weird ui_file_put
mechanism was possible.

- New ui_file::printf, ui_file::puts, etc. methods

These simplify / clarify client code.  I considered splitting
client-code changes, like these, e.g.:

  -  stb = mem_fileopen ();
  -  fprintf_unfiltered (stb, "%s%s%s",
  -		      _("The valid values are:\n"),
  -		      regdesc,
  -		      _("The default is \"std\"."));
  +  string_file stb;
  +  stb.printf ("%s%s%s",
  +	      _("The valid values are:\n"),
  +	      regdesc,
  +	      _("The default is \"std\"."));

In two steps, with the first step leaving fprintf_unfiltered (etc.)
calls in place, and only afterwards do a pass to change all those to
call stb.printf etc..  I didn't do that split, because (when I tried),
it turned out to be pointless make-work: the first pass would have to
touch the fprintf_unfiltered line anyway, to replace "stb" with
"&stb".

- gdb_fopen replaced with stack-based objects

This avoids the need for cleanups or unique_ptr's.  I.e., this:

      struct ui_file *file = gdb_fopen (filename, "w");
      if (filename == NULL)
 	perror_with_name (filename);
      cleanups = make_cleanup_ui_file_delete (file);
      // use file.
      do_cleanups (cleanups);

is replaced with this:

      stdio_file file;
      if (!file.open (filename, "w"))
 	perror_with_name (filename);
      // use file.

- odd contorsions in null_file_write / null_file_fputs around when to
  call to_fputs / to_write eliminated.

- Global null_stream object

A few places that were allocating a ui_file in order to print to
"nowhere" are adjusted to instead refer to a new 'null_stream' global
stream.

- TUI's tui_sfileopen eliminated.  TUI's ui_file much simplified

The TUI's ui_file was serving a dual purpose.  It supported being used
as string buffer, and supported being backed by a stdio FILE.  The
string buffer part is gone, replaced by using of string_file.  The
'FILE *' support is now much simplified, by making the TUI's ui_file
inherit from stdio_file.

gdb/ChangeLog:
2017-02-02  Pedro Alves  <palves@redhat.com>

	* ada-lang.c (type_as_string): Use string_file.
	* ada-valprint.c (ada_print_floating): Use string_file.
	* ada-varobj.c (ada_varobj_scalar_image)
	(ada_varobj_get_value_image): Use string_file.
	* aix-thread.c (aix_thread_extra_thread_info): Use string_file.
	* arm-tdep.c (_initialize_arm_tdep): Use string_printf.
	* breakpoint.c (update_inserted_breakpoint_locations)
	(insert_breakpoint_locations, reattach_breakpoints)
	(print_breakpoint_location, print_one_detail_ranged_breakpoint)
	(print_it_watchpoint): Use string_file.
	(save_breakpoints): Use stdio_file.
	* c-exp.y (oper): Use string_file.
	* cli/cli-logging.c (set_logging_redirect): Use ui_file_up and
	tee_file.
	(pop_output_files): Use delete.
	(handle_redirections): Use stdio_file and tee_file.
	* cli/cli-setshow.c (do_show_command): Use string_file.
	* compile/compile-c-support.c (c_compute_program): Use
	string_file.
	* compile/compile-c-symbols.c (generate_vla_size): Take a
	'string_file &' instead of a 'ui_file *'.
	(generate_c_for_for_one_variable): Take a 'string_file &' instead
	of a 'ui_file *'.  Use string_file.
	(generate_c_for_variable_locations): Take a 'string_file &'
	instead of a 'ui_file *'.
	* compile/compile-internal.h (generate_c_for_for_one_variable):
	Take a 'string_file &' instead of a 'ui_file *'.
	* compile/compile-loc2c.c (push, pushf, unary, binary)
	(print_label, pushf_register_address, pushf_register)
	(do_compile_dwarf_expr_to_c): Take a 'string_file &' instead of a
	'ui_file *'.  Adjust.
	* compile/compile.c (compile_to_object): Use string_file.
	* compile/compile.h (compile_dwarf_expr_to_c)
	(compile_dwarf_bounds_to_c): Take a 'string_file &' instead of a
	'ui_file *'.
	* cp-support.c (inspect_type): Use string_file and obstack_copy0.
	(replace_typedefs_qualified_name): Use string_file and
	obstack_copy0.
	* disasm.c (gdb_pretty_print_insn): Use string_file.
	(gdb_disassembly): Adjust reference the null_stream global.
	(do_ui_file_delete): Delete.
	(gdb_insn_length): Use null_stream.
	* dummy-frame.c (maintenance_print_dummy_frames): Use stdio_file.
	* dwarf2loc.c (dwarf2_compile_property_to_c)
	(locexpr_generate_c_location, loclist_generate_c_location): Take a
	'string_file &' instead of a 'ui_file *'.
	* dwarf2loc.h (dwarf2_compile_property_to_c): Likewise.
	* dwarf2read.c (do_ui_file_peek_last): Delete.
	(dwarf2_compute_name): Use string_file.
	* event-top.c (gdb_setup_readline): Use stdio_file.
	* gdbarch.sh (verify_gdbarch): Use string_file.
	* gdbtypes.c (safe_parse_type): Use null_stream.
	* guile/scm-breakpoint.c (gdbscm_breakpoint_commands): Use
	string_file.
	* guile/scm-disasm.c (gdbscm_print_insn_from_port): Take a
	'string_file *' instead of a 'ui_file *'.
	(gdbscm_arch_disassemble): Use string_file.
	* guile/scm-frame.c (frscm_print_frame_smob): Use string_file.
	* guile/scm-ports.c (class ioscm_file_port): Now a class that
	inherits from ui_file.
	(ioscm_file_port_delete, ioscm_file_port_rewind)
	(ioscm_file_port_put): Delete.
	(ioscm_file_port_write): Rename to ...
	(ioscm_file_port::write): ... this.  Remove file_port_magic
	checks.
	(ioscm_file_port_new): Delete.
	(ioscm_with_output_to_port_worker): Use ioscm_file_port and
	ui_file_up.
	* guile/scm-type.c (tyscm_type_name): Use string_file.
	* guile/scm-value.c (vlscm_print_value_smob, gdbscm_value_print):
	Use string_file.
	* infcmd.c (print_return_value_1): Use string_file.
	* infrun.c (print_target_wait_results): Use string_file.
	* language.c (add_language): Use string_file.
	* location.c (explicit_to_string_internal): Use string_file.
	* main.c (captured_main_1): Use null_file.
	* maint.c (maintenance_print_architecture): Use stdio_file.
	* mi/mi-cmd-stack.c (list_arg_or_local): Use string_file.
	* mi/mi-common.h (struct mi_interp) <out, err, log, targ,
	event_channel>: Change type to mi_console_file pointer.
	* mi/mi-console.c (mi_console_file_fputs, mi_console_file_flush)
	(mi_console_file_delete): Delete.
	(struct mi_console_file): Delete.
	(mi_console_file_magic): Delete.
	(mi_console_file_new): Delete.
	(mi_console_file::mi_console_file): New.
	(mi_console_file_delete): Delete.
	(mi_console_file_fputs): Delete.
	(mi_console_file::write): New.
	(mi_console_raw_packet): Delete.
	(mi_console_file::flush): New.
	(mi_console_file_flush): Delete.
	(mi_console_set_raw): Rename to ...
	(mi_console_file::set_raw): ... this.
	* mi/mi-console.h (class mi_console_file): New class.
	(mi_console_file_new, mi_console_set_raw): Delete.
	* mi/mi-interp.c (mi_interpreter_init): Use mi_console_file.
	(mi_set_logging): Use delete and tee_file.  Adjust.
	* mi/mi-main.c (output_register): Use string_file.
	(mi_cmd_data_evaluate_expression): Use string_file.
	(mi_cmd_data_read_memory): Use string_file.
	(mi_cmd_execute, print_variable_or_computed): Use string_file.
	* mi/mi-out.c (mi_ui_out::main_stream): New.
	(mi_ui_out::rewind): Use main_stream and
	string_file.
	(mi_ui_out::put): Use main_stream and string_file.
	(mi_ui_out::mi_ui_out): Remove 'stream' parameter.
	Allocate a 'string_file' instead.
	(mi_out_new): Don't allocate a mem_fileopen stream here.
	* mi/mi-out.h (mi_ui_out::mi_ui_out): Remove 'stream' parameter.
	(mi_ui_out::main_stream): Declare method.
	* printcmd.c (eval_command): Use string_file.
	* psymtab.c (maintenance_print_psymbols): Use stdio_file.
	* python/py-arch.c (archpy_disassemble): Use string_file.
	* python/py-breakpoint.c (bppy_get_commands): Use string_file.
	* python/py-frame.c (frapy_str): Use string_file.
	* python/py-framefilter.c (py_print_type, py_print_single_arg):
	Use string_file.
	* python/py-type.c (typy_str): Use string_file.
	* python/py-unwind.c (unwind_infopy_str): Use string_file.
	* python/py-value.c (valpy_str): Use string_file.
	* record-btrace.c (btrace_insn_history): Use string_file.
	* regcache.c (regcache_print): Use stdio_file.
	* reggroups.c (maintenance_print_reggroups): Use stdio_file.
	* remote.c (escape_buffer): Use string_file.
	* rust-lang.c (rust_get_disr_info): Use string_file.
	* serial.c (serial_open_ops_1): Use stdio_file.
	(do_serial_close): Use delete.
	* stack.c (print_frame_arg): Use string_file.
	(print_frame_args): Remove local mem_fileopen stream, not used.
	(print_frame): Use string_file.
	* symmisc.c (maintenance_print_symbols): Use stdio_file.
	* symtab.h (struct symbol_computed_ops) <generate_c_location>:
	Take a 'string_file *' instead of a 'ui_file *'.
	* top.c (new_ui): Use stdio_file and stderr_file.
	(free_ui): Use delete.
	(execute_command_to_string): Use string_file.
	(quit_confirm): Use string_file.
	* tracepoint.c (collection_list::append_exp): Use string_file.
	* tui/tui-disasm.c (tui_disassemble): Use string_file.
	* tui/tui-file.c: Don't include "ui-file.h".
	(enum streamtype, struct tui_stream): Delete.
	(tui_file_new, tui_file_delete, tui_fileopen, tui_sfileopen)
	(tui_file_isatty, tui_file_rewind, tui_file_put): Delete.
	(tui_file::tui_file): New method.
	(tui_file_fputs): Delete.
	(tui_file_get_strbuf): Delete.
	(tui_file::puts): New method.
	(tui_file_adjust_strbuf): Delete.
	(tui_file_flush): Delete.
	(tui_file::flush): New method.
	* tui/tui-file.h: Tweak intro comment.
	Include ui-file.h.
	(tui_fileopen, tui_sfileopen, tui_file_get_strbuf)
	(tui_file_adjust_strbuf): Delete declarations.
	(class tui_file): New class.
	* tui/tui-io.c (tui_initialize_io): Use tui_file.
	* tui/tui-regs.c (tui_restore_gdbout): Use delete.
	(tui_register_format): Use string_stream.
	* tui/tui-stack.c (tui_make_status_line): Use string_file.
	(tui_get_function_from_frame): Use string_file.
	* typeprint.c (type_to_string): Use string_file.
	* ui-file.c (struct ui_file, ui_file_magic, ui_file_new): Delete.
	(null_stream): New global.
	(ui_file_delete): Delete.
	(ui_file::ui_file): New.
	(null_file_isatty): Delete.
	(ui_file::~ui_file): New.
	(null_file_rewind): Delete.
	(ui_file::printf): New.
	(null_file_put): Delete.
	(null_file_flush): Delete.
	(ui_file::putstr): New.
	(null_file_write): Delete.
	(ui_file::putstrn): New.
	(null_file_read): Delete.
	(ui_file::putc): New.
	(null_file_fputs): Delete.
	(null_file_write_async_safe): Delete.
	(ui_file::vprintf): New.
	(null_file_delete): Delete.
	(null_file::write): New.
	(null_file_fseek): Delete.
	(null_file::puts): New.
	(ui_file_data): Delete.
	(null_file::write_async_safe): New.
	(gdb_flush, ui_file_isatty): Adjust.
	(ui_file_put, ui_file_rewind): Delete.
	(ui_file_write): Adjust.
	(ui_file_write_for_put): Delete.
	(ui_file_write_async_safe, ui_file_read): Adjust.
	(ui_file_fseek): Delete.
	(fputs_unfiltered): Adjust.
	(set_ui_file_flush, set_ui_file_isatty, set_ui_file_rewind)
	(set_ui_file_put, set_ui_file_write, set_ui_file_write_async_safe)
	(set_ui_file_read, set_ui_file_fputs, set_ui_file_fseek)
	(set_ui_file_data): Delete.
	(string_file::~string_file, string_file::write)
	(struct accumulated_ui_file, do_ui_file_xstrdup, ui_file_xstrdup)
	(do_ui_file_as_string, ui_file_as_string): Delete.
	(do_ui_file_obsavestring, ui_file_obsavestring): Delete.
	(struct mem_file): Delete.
	(mem_file_new): Delete.
	(stdio_file::stdio_file): New.
	(mem_file_delete): Delete.
	(stdio_file::stdio_file): New.
	(mem_fileopen): Delete.
	(stdio_file::~stdio_file): New.
	(mem_file_rewind): Delete.
	(stdio_file::set_stream): New.
	(mem_file_put): Delete.
	(stdio_file::open): New.
	(mem_file_write): Delete.
	(stdio_file_magic, struct stdio_file): Delete.
	(stdio_file_new, stdio_file_delete, stdio_file_flush): Delete.
	(stdio_file::flush): New.
	(stdio_file_read): Rename to ...
	(stdio_file::read): ... this.  Adjust.
	(stdio_file_write): Rename to ...
	(stdio_file::write): ... this.  Adjust.
	(stdio_file_write_async_safe): Rename to ...
	(stdio_file::write_async_safe) ... this.  Adjust.
	(stdio_file_fputs): Rename to ...
	(stdio_file::puts) ... this.  Adjust.
	(stdio_file_isatty): Delete.
	(stdio_file_fseek): Delete.
	(stdio_file::isatty): New.
	(stderr_file_write): Rename to ...
	(stderr_file::write) ... this.  Adjust.
	(stderr_file_fputs): Rename to ...
	(stderr_file::puts) ... this.  Adjust.
	(stderr_fileopen, stdio_fileopen, gdb_fopen): Delete.
	(stderr_file::stderr_file): New.
	(tee_file_magic): Delete.
	(struct tee_file): Delete.
	(tee_file::tee_file): New.
	(tee_file_new): Delete.
	(tee_file::~tee_file): New.
	(tee_file_delete): Delete.
	(tee_file_flush): Rename to ...
	(tee_file::flush): ... this.  Adjust.
	(tee_file_write): Rename to ...
	(tee_file::write): ... this.  Adjust.
	(tee_file::write_async_safe): New.
	(tee_file_fputs): Rename to ...
	(tee_file::puts): ... this.  Adjust.
	(tee_file_isatty): Rename to ...
	(tee_file::isatty): ... this.  Adjust.
	* ui-file.h (struct obstack, struct ui_file): Don't
	forward-declare.
	(ui_file_new, ui_file_flush_ftype, set_ui_file_flush)
	(ui_file_write_ftype)
	(set_ui_file_write, ui_file_fputs_ftype, set_ui_file_fputs)
	(ui_file_write_async_safe_ftype, set_ui_file_write_async_safe)
	(ui_file_read_ftype, set_ui_file_read, ui_file_isatty_ftype)
	(set_ui_file_isatty, ui_file_rewind_ftype, set_ui_file_rewind)
	(ui_file_put_method_ftype, ui_file_put_ftype, set_ui_file_put)
	(ui_file_delete_ftype, set_ui_file_data, ui_file_fseek_ftype)
	(set_ui_file_fseek): Delete.
	(ui_file_data, ui_file_delete, ui_file_rewind)
	(struct ui_file): New.
	(ui_file_up): New.
	(class null_file): New.
	(null_stream): Declare.
	(ui_file_write_for_put, ui_file_put): Delete.
	(ui_file_xstrdup, ui_file_as_string, ui_file_obsavestring):
	Delete.
	(ui_file_fseek, mem_fileopen, stdio_fileopen, stderr_fileopen)
	(gdb_fopen, tee_file_new): Delete.
	(struct string_file): New.
	(struct stdio_file): New.
	(stdio_file_up): New.
	(struct stderr_file): New.
	(class tee_file): New.
	* ui-out.c (ui_out::field_stream): Take a 'string_file &' instead
	of a 'ui_file *'.  Adjust.
	* ui-out.h (class ui_out) <field_stream>: Likewise.
	* utils.c (do_ui_file_delete, make_cleanup_ui_file_delete)
	(null_stream): Delete.
	(error_stream): Take a 'string_file &' instead of a 'ui_file *'.
	Adjust.
	* utils.h (struct ui_file): Delete forward declaration..
	(make_cleanup_ui_file_delete, null_stream): Delete declarations.
	(error_stream): Take a 'string_file &' instead of a
	'ui_file *'.
	* varobj.c (varobj_value_get_print_value): Use string_file.
	* xtensa-tdep.c (xtensa_verify_config): Use string_file.
	* gdbarch.c: Regenerate.

6 files changed, 95 insertions, 110 deletions

diff --git a/gdb/compile/compile-c-support.c b/gdb/compile/compile-c-support.c
index 877bfb7..7ad0a87 100644
--- a/gdb/compile/compile-c-support.c
+++ b/gdb/compile/compile-c-support.c
@@ -333,15 +333,12 @@ c_compute_program (struct compile_instance *inst,
 		   const struct block *expr_block,
 		   CORE_ADDR expr_pc)
 {
-  struct ui_file *buf, *var_stream = NULL;
-  std::string code;
-  struct cleanup *cleanup;
   struct compile_c_instance *context = (struct compile_c_instance *) inst;
 
-  buf = mem_fileopen ();
-  cleanup = make_cleanup_ui_file_delete (buf);
+  string_file buf;
+  string_file var_stream;
 
-  write_macro_definitions (expr_block, expr_pc, buf);
+  write_macro_definitions (expr_block, expr_pc, &buf);
 
   /* Do not generate local variable information for "raw"
      compilations.  In this case we aren't emitting our own function
@@ -355,21 +352,17 @@ c_compute_program (struct compile_instance *inst,
 	 before generating the function header, so we can define the
 	 register struct before the function body.  This requires a
 	 temporary stream.  */
-      var_stream = mem_fileopen ();
-      make_cleanup_ui_file_delete (var_stream);
       registers_used = generate_c_for_variable_locations (context,
 							  var_stream, gdbarch,
 							  expr_block, expr_pc);
       make_cleanup (xfree, registers_used);
 
-      fputs_unfiltered ("typedef unsigned int"
-			" __attribute__ ((__mode__(__pointer__)))"
-			" __gdb_uintptr;\n",
-			buf);
-      fputs_unfiltered ("typedef int"
-			" __attribute__ ((__mode__(__pointer__)))"
-			" __gdb_intptr;\n",
-			buf);
+      buf.puts ("typedef unsigned int"
+		" __attribute__ ((__mode__(__pointer__)))"
+		" __gdb_uintptr;\n");
+      buf.puts ("typedef int"
+		" __attribute__ ((__mode__(__pointer__)))"
+		" __gdb_intptr;\n");
 
       /* Iterate all log2 sizes in bytes supported by c_get_mode_for_size.  */
       for (i = 0; i < 4; ++i)
@@ -377,24 +370,23 @@ c_compute_program (struct compile_instance *inst,
 	  const char *mode = c_get_mode_for_size (1 << i);
 
 	  gdb_assert (mode != NULL);
-	  fprintf_unfiltered (buf,
-			      "typedef int"
-			      " __attribute__ ((__mode__(__%s__)))"
-			      " __gdb_int_%s;\n",
-			      mode, mode);
+	  buf.printf ("typedef int"
+		      " __attribute__ ((__mode__(__%s__)))"
+		      " __gdb_int_%s;\n",
+		      mode, mode);
 	}
 
-      generate_register_struct (buf, gdbarch, registers_used);
+      generate_register_struct (&buf, gdbarch, registers_used);
     }
 
-  add_code_header (inst->scope, buf);
+  add_code_header (inst->scope, &buf);
 
   if (inst->scope == COMPILE_I_SIMPLE_SCOPE
       || inst->scope == COMPILE_I_PRINT_ADDRESS_SCOPE
       || inst->scope == COMPILE_I_PRINT_VALUE_SCOPE)
     {
-      ui_file_put (var_stream, ui_file_write_for_put, buf);
-      fputs_unfiltered ("#pragma GCC user_expression\n", buf);
+      buf.write (var_stream.c_str (), var_stream.size ());
+      buf.puts ("#pragma GCC user_expression\n");
     }
 
   /* The user expression has to be in its own scope, so that "extern"
@@ -402,15 +394,15 @@ c_compute_program (struct compile_instance *inst,
      declaration is in the same scope as the declaration provided by
      gdb.  */
   if (inst->scope != COMPILE_I_RAW_SCOPE)
-    fputs_unfiltered ("{\n", buf);
+    buf.puts ("{\n");
 
-  fputs_unfiltered ("#line 1 \"gdb command line\"\n", buf);
+  buf.puts ("#line 1 \"gdb command line\"\n");
 
   switch (inst->scope)
     {
     case COMPILE_I_PRINT_ADDRESS_SCOPE:
     case COMPILE_I_PRINT_VALUE_SCOPE:
-      fprintf_unfiltered (buf,
+      buf.printf (
 "__auto_type " COMPILE_I_EXPR_VAL " = %s;\n"
 "typeof (%s) *" COMPILE_I_EXPR_PTR_TYPE ";\n"
 "memcpy (" COMPILE_I_PRINT_OUT_ARG ", %s" COMPILE_I_EXPR_VAL ",\n"
@@ -420,22 +412,20 @@ c_compute_program (struct compile_instance *inst,
 			   ? "&" : ""));
       break;
     default:
-      fputs_unfiltered (input, buf);
+      buf.puts (input);
       break;
     }
 
-  fputs_unfiltered ("\n", buf);
+  buf.puts ("\n");
 
   /* For larger user expressions the automatic semicolons may be
      confusing.  */
   if (strchr (input, '\n') == NULL)
-    fputs_unfiltered (";\n", buf);
+    buf.puts (";\n");
 
   if (inst->scope != COMPILE_I_RAW_SCOPE)
-    fputs_unfiltered ("}\n", buf);
+    buf.puts ("}\n");
 
-  add_code_footer (inst->scope, buf);
-  code = ui_file_as_string (buf);
-  do_cleanups (cleanup);
-  return code;
+  add_code_footer (inst->scope, &buf);
+  return std::move (buf.string ());
 }
diff --git a/gdb/compile/compile-c-symbols.c b/gdb/compile/compile-c-symbols.c
index 6010006..9282cfc 100644
--- a/gdb/compile/compile-c-symbols.c
+++ b/gdb/compile/compile-c-symbols.c
@@ -584,7 +584,7 @@ symbol_seen (htab_t hashtab, struct symbol *sym)
 
 static void
 generate_vla_size (struct compile_c_instance *compiler,
-		   struct ui_file *stream,
+		   string_file &stream,
 		   struct gdbarch *gdbarch,
 		   unsigned char *registers_used,
 		   CORE_ADDR pc,
@@ -640,7 +640,7 @@ generate_vla_size (struct compile_c_instance *compiler,
 
 static void
 generate_c_for_for_one_variable (struct compile_c_instance *compiler,
-				 struct ui_file *stream,
+				 string_file &stream,
 				 struct gdbarch *gdbarch,
 				 unsigned char *registers_used,
 				 CORE_ADDR pc,
@@ -651,14 +651,14 @@ generate_c_for_for_one_variable (struct compile_c_instance *compiler,
     {
       if (is_dynamic_type (SYMBOL_TYPE (sym)))
 	{
-	  struct ui_file *size_file = mem_fileopen ();
-	  struct cleanup *cleanup = make_cleanup_ui_file_delete (size_file);
+	  /* We need to emit to a temporary buffer in case an error
+	     occurs in the middle.  */
+	  string_file local_file;
 
-	  generate_vla_size (compiler, size_file, gdbarch, registers_used, pc,
+	  generate_vla_size (compiler, local_file, gdbarch, registers_used, pc,
 			     SYMBOL_TYPE (sym), sym);
-	  ui_file_put (size_file, ui_file_write_for_put, stream);
 
-	  do_cleanups (cleanup);
+	  stream.write (local_file.c_str (), local_file.size ());
 	}
 
       if (SYMBOL_COMPUTED_OPS (sym) != NULL)
@@ -667,14 +667,13 @@ generate_c_for_for_one_variable (struct compile_c_instance *compiler,
 	  struct cleanup *cleanup = make_cleanup (xfree, generated_name);
 	  /* We need to emit to a temporary buffer in case an error
 	     occurs in the middle.  */
-	  struct ui_file *local_file = mem_fileopen ();
+	  string_file local_file;
 
-	  make_cleanup_ui_file_delete (local_file);
 	  SYMBOL_COMPUTED_OPS (sym)->generate_c_location (sym, local_file,
 							  gdbarch,
 							  registers_used,
 							  pc, generated_name);
-	  ui_file_put (local_file, ui_file_write_for_put, stream);
+	  stream.write (local_file.c_str (), local_file.size ());
 
 	  do_cleanups (cleanup);
 	}
@@ -719,7 +718,7 @@ generate_c_for_for_one_variable (struct compile_c_instance *compiler,
 
 unsigned char *
 generate_c_for_variable_locations (struct compile_c_instance *compiler,
-				   struct ui_file *stream,
+				   string_file &stream,
 				   struct gdbarch *gdbarch,
 				   const struct block *block,
 				   CORE_ADDR pc)
diff --git a/gdb/compile/compile-internal.h b/gdb/compile/compile-internal.h
index 4bf5bf9..0c53f8c 100644
--- a/gdb/compile/compile-internal.h
+++ b/gdb/compile/compile-internal.h
@@ -135,7 +135,7 @@ extern struct compile_instance *new_compile_instance (struct gcc_c_context *fe);
 
 extern unsigned char *generate_c_for_variable_locations
      (struct compile_c_instance *compiler,
-      struct ui_file *stream,
+      string_file &stream,
       struct gdbarch *gdbarch,
       const struct block *block,
       CORE_ADDR pc);
diff --git a/gdb/compile/compile-loc2c.c b/gdb/compile/compile-loc2c.c
index 81684d1..f1296e8 100644
--- a/gdb/compile/compile-loc2c.c
+++ b/gdb/compile/compile-loc2c.c
@@ -435,9 +435,9 @@ compute_stack_depth (enum bfd_endian byte_order, unsigned int addr_size,
 /* Emit code to push a constant.  */
 
 static void
-push (int indent, struct ui_file *stream, ULONGEST l)
+push (int indent, string_file &stream, ULONGEST l)
 {
-  fprintfi_filtered (indent, stream,
+  fprintfi_filtered (indent, &stream,
 		     "__gdb_stack[++__gdb_tos] = (" GCC_UINTPTR ") %s;\n",
 		     hex_string (l));
 }
@@ -445,57 +445,57 @@ push (int indent, struct ui_file *stream, ULONGEST l)
 /* Emit code to push an arbitrary expression.  This works like
    printf.  */
 
-static void pushf (int indent, struct ui_file *stream, const char *format, ...)
+static void pushf (int indent, string_file &stream, const char *format, ...)
   ATTRIBUTE_PRINTF (3, 4);
 
 static void
-pushf (int indent, struct ui_file *stream, const char *format, ...)
+pushf (int indent, string_file &stream, const char *format, ...)
 {
   va_list args;
 
-  fprintfi_filtered (indent, stream, "__gdb_stack[__gdb_tos + 1] = ");
+  fprintfi_filtered (indent, &stream, "__gdb_stack[__gdb_tos + 1] = ");
   va_start (args, format);
-  vfprintf_filtered (stream, format, args);
+  stream.vprintf (format, args);
   va_end (args);
-  fprintf_filtered (stream, ";\n");
+  stream.puts (";\n");
 
-  fprintfi_filtered (indent, stream, "++__gdb_tos;\n");
+  fprintfi_filtered (indent, &stream, "++__gdb_tos;\n");
 }
 
 /* Emit code for a unary expression -- one which operates in-place on
    the top-of-stack.  This works like printf.  */
 
-static void unary (int indent, struct ui_file *stream, const char *format, ...)
+static void unary (int indent, string_file &stream, const char *format, ...)
   ATTRIBUTE_PRINTF (3, 4);
 
 static void
-unary (int indent, struct ui_file *stream, const char *format, ...)
+unary (int indent, string_file &stream, const char *format, ...)
 {
   va_list args;
 
-  fprintfi_filtered (indent, stream, "__gdb_stack[__gdb_tos] = ");
+  fprintfi_filtered (indent, &stream, "__gdb_stack[__gdb_tos] = ");
   va_start (args, format);
-  vfprintf_filtered (stream, format, args);
+  stream.vprintf (format, args);
   va_end (args);
-  fprintf_filtered (stream, ";\n");
+  stream.puts (";\n");
 }
 
 /* Emit code for a unary expression -- one which uses the top two
    stack items, popping the topmost one.  This works like printf.  */
-static void binary (int indent, struct ui_file *stream, const char *format, ...)
+static void binary (int indent, string_file &stream, const char *format, ...)
   ATTRIBUTE_PRINTF (3, 4);
 
 static void
-binary (int indent, struct ui_file *stream, const char *format, ...)
+binary (int indent, string_file &stream, const char *format, ...)
 {
   va_list args;
 
-  fprintfi_filtered (indent, stream, "__gdb_stack[__gdb_tos - 1] = ");
+  fprintfi_filtered (indent, &stream, "__gdb_stack[__gdb_tos - 1] = ");
   va_start (args, format);
-  vfprintf_filtered (stream, format, args);
+  stream.vprintf (format, args);
   va_end (args);
-  fprintf_filtered (stream, ";\n");
-  fprintfi_filtered (indent, stream, "--__gdb_tos;\n");
+  stream.puts (";\n");
+  fprintfi_filtered (indent, &stream, "--__gdb_tos;\n");
 }
 
 /* Print the name of a label given its "SCOPE", an arbitrary integer
@@ -503,10 +503,9 @@ binary (int indent, struct ui_file *stream, const char *format, ...)
    corresponding to the label's point of definition.  */
 
 static void
-print_label (struct ui_file *stream, unsigned int scope, int target)
+print_label (string_file &stream, unsigned int scope, int target)
 {
-  fprintf_filtered (stream, "__label_%u_%s",
-		    scope, pulongest (target));
+  stream.printf ("__label_%u_%s", scope, pulongest (target));
 }
 
 /* Emit code that pushes a register's address on the stack.
@@ -514,7 +513,7 @@ print_label (struct ui_file *stream, unsigned int scope, int target)
    register was needed by this expression.  */
 
 static void
-pushf_register_address (int indent, struct ui_file *stream,
+pushf_register_address (int indent, string_file &stream,
 			unsigned char *registers_used,
 			struct gdbarch *gdbarch, int regnum)
 {
@@ -535,7 +534,7 @@ pushf_register_address (int indent, struct ui_file *stream,
    register's value before it is pushed.  */
 
 static void
-pushf_register (int indent, struct ui_file *stream,
+pushf_register (int indent, string_file &stream,
 		unsigned char *registers_used,
 		struct gdbarch *gdbarch, int regnum, uint64_t offset)
 {
@@ -584,7 +583,7 @@ pushf_register (int indent, struct ui_file *stream,
    things.  */
 
 static void
-do_compile_dwarf_expr_to_c (int indent, struct ui_file *stream,
+do_compile_dwarf_expr_to_c (int indent, string_file &stream,
 			    const char *type_name,
 			    const char *result_name,
 			    struct symbol *sym, CORE_ADDR pc,
@@ -609,9 +608,9 @@ do_compile_dwarf_expr_to_c (int indent, struct ui_file *stream,
 
   ++scope;
 
-  fprintfi_filtered (indent, stream, "__attribute__ ((unused)) %s %s;\n",
+  fprintfi_filtered (indent, &stream, "__attribute__ ((unused)) %s %s;\n",
 		     type_name, result_name);
-  fprintfi_filtered (indent, stream, "{\n");
+  fprintfi_filtered (indent, &stream, "{\n");
   indent += 2;
 
   stack_depth = compute_stack_depth (byte_order, addr_size,
@@ -648,20 +647,20 @@ do_compile_dwarf_expr_to_c (int indent, struct ui_file *stream,
 		 "compiled code."),
 	       SYMBOL_PRINT_NAME (sym));
 
-      fprintfi_filtered (indent, stream, "%s = %s;\n",
+      fprintfi_filtered (indent, &stream, "%s = %s;\n",
 			 result_name,
 			 core_addr_to_string (value_address (val)));
-      fprintfi_filtered (indent - 2, stream, "}\n");
+      fprintfi_filtered (indent - 2, &stream, "}\n");
       do_cleanups (cleanup);
       return;
     }
 
-  fprintfi_filtered (indent, stream, GCC_UINTPTR " __gdb_stack[%d];\n",
+  fprintfi_filtered (indent, &stream, GCC_UINTPTR " __gdb_stack[%d];\n",
 		     stack_depth);
 
   if (need_tempvar)
-    fprintfi_filtered (indent, stream, GCC_UINTPTR " __gdb_tmp;\n");
-  fprintfi_filtered (indent, stream, "int __gdb_tos = -1;\n");
+    fprintfi_filtered (indent, &stream, GCC_UINTPTR " __gdb_tmp;\n");
+  fprintfi_filtered (indent, &stream, "int __gdb_tos = -1;\n");
 
   if (initial != NULL)
     pushf (indent, stream, "%s", core_addr_to_string (*initial));
@@ -672,13 +671,13 @@ do_compile_dwarf_expr_to_c (int indent, struct ui_file *stream,
       uint64_t uoffset, reg;
       int64_t offset;
 
-      print_spaces (indent - 2, stream);
+      print_spaces (indent - 2, &stream);
       if (info[op_ptr - base].label)
 	{
 	  print_label (stream, scope, op_ptr - base);
-	  fprintf_filtered (stream, ":;");
+	  stream.puts (":;");
 	}
-      fprintf_filtered (stream, "/* %s */\n", get_DW_OP_name (op));
+      stream.printf ("/* %s */\n", get_DW_OP_name (op));
 
       /* This is handy for debugging the generated code:
       fprintf_filtered (stream, "if (__gdb_tos != %d) abort ();\n",
@@ -919,7 +918,7 @@ do_compile_dwarf_expr_to_c (int indent, struct ui_file *stream,
 	  break;
 
 	case DW_OP_drop:
-	  fprintfi_filtered (indent, stream, "--__gdb_tos;\n");
+	  fprintfi_filtered (indent, &stream, "--__gdb_tos;\n");
 	  break;
 
 	case DW_OP_pick:
@@ -929,13 +928,13 @@ do_compile_dwarf_expr_to_c (int indent, struct ui_file *stream,
 	  break;
 
 	case DW_OP_swap:
-	  fprintfi_filtered (indent, stream,
+	  fprintfi_filtered (indent, &stream,
 			     "__gdb_tmp = __gdb_stack[__gdb_tos - 1];\n");
-	  fprintfi_filtered (indent, stream,
+	  fprintfi_filtered (indent, &stream,
 			     "__gdb_stack[__gdb_tos - 1] = "
 			     "__gdb_stack[__gdb_tos];\n");
-	  fprintfi_filtered (indent, stream, ("__gdb_stack[__gdb_tos] = "
-					      "__gdb_tmp;\n"));
+	  fprintfi_filtered (indent, &stream, ("__gdb_stack[__gdb_tos] = "
+					       "__gdb_tmp;\n"));
 	  break;
 
 	case DW_OP_over:
@@ -943,15 +942,15 @@ do_compile_dwarf_expr_to_c (int indent, struct ui_file *stream,
 	  break;
 
 	case DW_OP_rot:
-	  fprintfi_filtered (indent, stream, ("__gdb_tmp = "
-					      "__gdb_stack[__gdb_tos];\n"));
-	  fprintfi_filtered (indent, stream,
+	  fprintfi_filtered (indent, &stream, ("__gdb_tmp = "
+					       "__gdb_stack[__gdb_tos];\n"));
+	  fprintfi_filtered (indent, &stream,
 			     "__gdb_stack[__gdb_tos] = "
 			     "__gdb_stack[__gdb_tos - 1];\n");
-	  fprintfi_filtered (indent, stream,
+	  fprintfi_filtered (indent, &stream,
 			     "__gdb_stack[__gdb_tos - 1] = "
 			     "__gdb_stack[__gdb_tos -2];\n");
-	  fprintfi_filtered (indent, stream, "__gdb_stack[__gdb_tos - 2] = "
+	  fprintfi_filtered (indent, &stream, "__gdb_stack[__gdb_tos - 2] = "
 			     "__gdb_tmp;\n");
 	  break;
 
@@ -973,7 +972,7 @@ do_compile_dwarf_expr_to_c (int indent, struct ui_file *stream,
 
 	    /* Cast to a pointer of the desired type, then
 	       dereference.  */
-	    fprintfi_filtered (indent, stream,
+	    fprintfi_filtered (indent, &stream,
 			       "__gdb_stack[__gdb_tos] = "
 			       "*((__gdb_int_%s *) "
 			       "__gdb_stack[__gdb_tos]);\n",
@@ -1099,19 +1098,19 @@ do_compile_dwarf_expr_to_c (int indent, struct ui_file *stream,
 	case DW_OP_skip:
 	  offset = extract_signed_integer (op_ptr, 2, byte_order);
 	  op_ptr += 2;
-	  fprintfi_filtered (indent, stream, "goto ");
+	  fprintfi_filtered (indent, &stream, "goto ");
 	  print_label (stream, scope, op_ptr + offset - base);
-	  fprintf_filtered (stream, ";\n");
+	  stream.puts (";\n");
 	  break;
 
 	case DW_OP_bra:
 	  offset = extract_signed_integer (op_ptr, 2, byte_order);
 	  op_ptr += 2;
-	  fprintfi_filtered (indent, stream,
+	  fprintfi_filtered (indent, &stream,
 			     "if ((( " GCC_INTPTR
 			     ") __gdb_stack[__gdb_tos--]) != 0) goto ");
 	  print_label (stream, scope, op_ptr + offset - base);
-	  fprintf_filtered (stream, ";\n");
+	  stream.puts (";\n");
 	  break;
 
 	case DW_OP_nop:
@@ -1122,9 +1121,9 @@ do_compile_dwarf_expr_to_c (int indent, struct ui_file *stream,
 	}
     }
 
-  fprintfi_filtered (indent, stream, "%s = __gdb_stack[__gdb_tos];\n",
+  fprintfi_filtered (indent, &stream, "%s = __gdb_stack[__gdb_tos];\n",
 		     result_name);
-  fprintfi_filtered (indent - 2, stream, "}\n");
+  fprintfi_filtered (indent - 2, &stream, "}\n");
 
   do_cleanups (cleanup);
 }
@@ -1132,7 +1131,7 @@ do_compile_dwarf_expr_to_c (int indent, struct ui_file *stream,
 /* See compile.h.  */
 
 void
-compile_dwarf_expr_to_c (struct ui_file *stream, const char *result_name,
+compile_dwarf_expr_to_c (string_file &stream, const char *result_name,
 			 struct symbol *sym, CORE_ADDR pc,
 			 struct gdbarch *arch, unsigned char *registers_used,
 			 unsigned int addr_size,
@@ -1147,7 +1146,7 @@ compile_dwarf_expr_to_c (struct ui_file *stream, const char *result_name,
 /* See compile.h.  */
 
 void
-compile_dwarf_bounds_to_c (struct ui_file *stream,
+compile_dwarf_bounds_to_c (string_file &stream,
 			   const char *result_name,
 			   const struct dynamic_prop *prop,
 			   struct symbol *sym, CORE_ADDR pc,
diff --git a/gdb/compile/compile.c b/gdb/compile/compile.c
index 0ae2125..b525f61 100644
--- a/gdb/compile/compile.c
+++ b/gdb/compile/compile.c
@@ -494,22 +494,19 @@ compile_to_object (struct command_line *cmd, const char *cmd_string,
   /* From the provided expression, build a scope to pass to the
      compiler.  */
 
-  std::string input_buf;
+  string_file input_buf;
   const char *input;
 
   if (cmd != NULL)
     {
-      struct ui_file *stream = mem_fileopen ();
       struct command_line *iter;
 
-      make_cleanup_ui_file_delete (stream);
       for (iter = cmd->body_list[0]; iter; iter = iter->next)
 	{
-	  fputs_unfiltered (iter->line, stream);
-	  fputs_unfiltered ("\n", stream);
+	  input_buf.puts (iter->line);
+	  input_buf.puts ("\n");
 	}
 
-      input_buf = ui_file_as_string (stream);
       input = input_buf.c_str ();
     }
   else if (cmd_string != NULL)
diff --git a/gdb/compile/compile.h b/gdb/compile/compile.h
index a46ee6d..7438599 100644
--- a/gdb/compile/compile.h
+++ b/gdb/compile/compile.h
@@ -55,7 +55,7 @@ extern void eval_compile_command (struct command_line *cmd,
    PER_CU is the per-CU object used for looking up various other
    things.  */
 
-extern void compile_dwarf_expr_to_c (struct ui_file *stream,
+extern void compile_dwarf_expr_to_c (string_file &stream,
 				     const char *result_name,
 				     struct symbol *sym,
 				     CORE_ADDR pc,
@@ -90,7 +90,7 @@ extern void compile_dwarf_expr_to_c (struct ui_file *stream,
    PER_CU is the per-CU object used for looking up various other
    things.  */
 
-extern void compile_dwarf_bounds_to_c (struct ui_file *stream,
+extern void compile_dwarf_bounds_to_c (string_file &stream,
 				       const char *result_name,
 				       const struct dynamic_prop *prop,
 				       struct symbol *sym, CORE_ADDR pc,