[PATCH 2/2] mi-out: Implement mi redirection using a stack.

[Adrian Sendroiu <adrian dot sendroiu at freescale dot com>]

gdb/
2014-07-23  Adrian Sendroiu  <adrian.sendroiu@freescale.com>

	* mi/mi-out.c (ui_filep): New typedef.
	(DEF_VEC_P (ui_filep)): New type.
	(struct ui_out_data): <buffer> Remove field.
	<original_buffer> Remove field.
	<streams>: New field.
	(mi_field_string): Get the output stream from the top of the
	stack of streams.
	(mi_field_fmt): Likewise.
	(mi_flush): Likewise.
	(field_separator): Likewise.
	(mi_open): Likewise.
	(mi_close): Likewise.
	(mi_out_buffered): Likewise.
	(mi_out_rewind): Likewise.
	(mi_out_put): Likewise.
	(mi_out_new): Initialize the stack of streams. Push a newly
	created stream on the stack.
	(mi_redirect): Reimplement using push and pop operations.
---
 gdb/mi/mi-out.c |   75 ++++++++++++++++++++++++++++++++-----------------------
 1 file changed, 44 insertions(+), 31 deletions(-)

diff --git a/gdb/mi/mi-out.c b/gdb/mi/mi-out.c
index 6ec41e6..4452080 100644
--- a/gdb/mi/mi-out.c
+++ b/gdb/mi/mi-out.c
@@ -22,14 +22,17 @@
 #include "defs.h"
 #include "ui-out.h"
 #include "mi-out.h"
+#include "vec.h"
+
+typedef struct ui_file *ui_filep;
+DEF_VEC_P (ui_filep);
 
 struct ui_out_data
   {
     int suppress_field_separator;
     int suppress_output;
     int mi_version;
-    struct ui_file *buffer;
-    struct ui_file *original_buffer;
+    VEC (ui_filep) *streams;
   };
 typedef struct ui_out_data mi_out_data;
 
@@ -215,17 +218,20 @@ mi_field_string (struct ui_out *uiout, int fldno, int width,
 		 enum ui_align align, const char *fldname, const char *string)
 {
   mi_out_data *data = ui_out_data (uiout);
+  struct ui_file *stream;
 
   if (data->suppress_output)
     return;
 
+  stream = VEC_last (ui_filep, data->streams);
+
   field_separator (uiout);
   if (fldname)
-    fprintf_unfiltered (data->buffer, "%s=", fldname);
-  fprintf_unfiltered (data->buffer, "\"");
+    fprintf_unfiltered (stream, "%s=", fldname);
+  fprintf_unfiltered (stream, "\"");
   if (string)
-    fputstr_unfiltered (string, '"', data->buffer);
-  fprintf_unfiltered (data->buffer, "\"");
+    fputstr_unfiltered (string, '"', stream);
+  fprintf_unfiltered (stream, "\"");
 }
 
 /* This is the only field function that does not align.  */
@@ -236,17 +242,20 @@ mi_field_fmt (struct ui_out *uiout, int fldno, int width,
 	      const char *format, va_list args)
 {
   mi_out_data *data = ui_out_data (uiout);
+  struct ui_file *stream;
 
   if (data->suppress_output)
     return;
 
+  stream = VEC_last (ui_filep, data->streams);
+
   field_separator (uiout);
   if (fldname)
-    fprintf_unfiltered (data->buffer, "%s=\"", fldname);
+    fprintf_unfiltered (stream, "%s=\"", fldname);
   else
-    fputs_unfiltered ("\"", data->buffer);
-  vfprintf_unfiltered (data->buffer, format, args);
-  fputs_unfiltered ("\"", data->buffer);
+    fputs_unfiltered ("\"", stream);
+  vfprintf_unfiltered (stream, format, args);
+  fputs_unfiltered ("\"", stream);
 }
 
 void
@@ -275,8 +284,9 @@ void
 mi_flush (struct ui_out *uiout)
 {
   mi_out_data *data = ui_out_data (uiout);
+  struct ui_file *stream = VEC_last (ui_filep, data->streams);
 
-  gdb_flush (data->buffer);
+  gdb_flush (stream);
 }
 
 int
@@ -285,15 +295,9 @@ mi_redirect (struct ui_out *uiout, struct ui_file *outstream)
   mi_out_data *data = ui_out_data (uiout);
 
   if (outstream != NULL)
-    {
-      data->original_buffer = data->buffer;
-      data->buffer = outstream;
-    }
-  else if (data->original_buffer != NULL)
-    {
-      data->buffer = data->original_buffer;
-      data->original_buffer = NULL;
-    }
+    VEC_safe_push (ui_filep, data->streams, outstream);
+  else
+    VEC_pop (ui_filep, data->streams);
 
   return 0;
 }
@@ -306,29 +310,31 @@ static void
 field_separator (struct ui_out *uiout)
 {
   mi_out_data *data = ui_out_data (uiout);
+  struct ui_file *stream = VEC_last (ui_filep, data->streams);
 
   if (data->suppress_field_separator)
     data->suppress_field_separator = 0;
   else
-    fputc_unfiltered (',', data->buffer);
+    fputc_unfiltered (',', stream);
 }
 
 static void
 mi_open (struct ui_out *uiout, const char *name, enum ui_out_type type)
 {
   mi_out_data *data = ui_out_data (uiout);
+  struct ui_file *stream = VEC_last (ui_filep, data->streams);
 
   field_separator (uiout);
   data->suppress_field_separator = 1;
   if (name)
-    fprintf_unfiltered (data->buffer, "%s=", name);
+    fprintf_unfiltered (stream, "%s=", name);
   switch (type)
     {
     case ui_out_type_tuple:
-      fputc_unfiltered ('{', data->buffer);
+      fputc_unfiltered ('{', stream);
       break;
     case ui_out_type_list:
-      fputc_unfiltered ('[', data->buffer);
+      fputc_unfiltered ('[', stream);
       break;
     default:
       internal_error (__FILE__, __LINE__, _("bad switch"));
@@ -339,14 +345,15 @@ static void
 mi_close (struct ui_out *uiout, enum ui_out_type type)
 {
   mi_out_data *data = ui_out_data (uiout);
+  struct ui_file *stream = VEC_last (ui_filep, data->streams);
 
   switch (type)
     {
     case ui_out_type_tuple:
-      fputc_unfiltered ('}', data->buffer);
+      fputc_unfiltered ('}', stream);
       break;
     case ui_out_type_list:
-      fputc_unfiltered (']', data->buffer);
+      fputc_unfiltered (']', stream);
       break;
     default:
       internal_error (__FILE__, __LINE__, _("bad switch"));
@@ -360,8 +367,9 @@ void
 mi_out_buffered (struct ui_out *uiout, char *string)
 {
   mi_out_data *data = ui_out_data (uiout);
+  struct ui_file *stream = VEC_last (ui_filep, data->streams);
 
-  fprintf_unfiltered (data->buffer, "%s", string);
+  fprintf_unfiltered (stream, "%s", string);
 }
 
 /* Clear the buffer.  */
@@ -370,8 +378,9 @@ void
 mi_out_rewind (struct ui_out *uiout)
 {
   mi_out_data *data = ui_out_data (uiout);
+  struct ui_file *stream = VEC_last (ui_filep, data->streams);
 
-  ui_file_rewind (data->buffer);
+  ui_file_rewind (stream);
 }
 
 /* Dump the buffer onto the specified stream.  */
@@ -386,9 +395,10 @@ void
 mi_out_put (struct ui_out *uiout, struct ui_file *stream)
 {
   mi_out_data *data = ui_out_data (uiout);
+  struct ui_file *current_stream = VEC_last (ui_filep, data->streams);
 
-  ui_file_put (data->buffer, do_write, stream);
-  ui_file_rewind (data->buffer);
+  ui_file_put (current_stream, do_write, stream);
+  ui_file_rewind (current_stream);
 }
 
 /* Return the current MI version.  */
@@ -407,6 +417,7 @@ struct ui_out *
 mi_out_new (int mi_version)
 {
   int flags = 0;
+  struct ui_file *new_stream;
 
   mi_out_data *data = XNEW (mi_out_data);
   data->suppress_field_separator = 0;
@@ -414,6 +425,8 @@ mi_out_new (int mi_version)
   data->mi_version = mi_version;
   /* FIXME: This code should be using a ``string_file'' and not the
      TUI buffer hack. */
-  data->buffer = mem_fileopen ();
+  data->streams = NULL;
+  new_stream = mem_fileopen();
+  VEC_safe_push (ui_filep, data->streams, new_stream);
   return ui_out_new (&mi_ui_out_impl, data, flags);
 }
-- 
1.7.9.5