PR mi/18833 gdb.execute ("set param value", to_string=True) will crash gdb if using MI

gdb/ChangeLog:

	* cli/cli-logging.c (pop_output_files): Don't restore redirection
	if MI-like.
	* mi/mi-out.c: #include "vec.h".
	(ui_filep): New type.
	(DEV_VEC_P (ui_filep)): New type.
	(struct ui_out_data) <buffer, original_buffer>: Delete.
	(struct ui_out_data) <streams>: New member.
	(mi_ui_out_impl): Add data_destroy field.
	(mi_field_string, mi_field_fmt): Update.
	(mi_flush, mi_redirect, field_separator): Update.
	(mi_open, mi_close): Update.
	(mi_out_buffered, mi_out_rewind, mi_out_put): Update.
	(mi_out_data_ctor, mi_out_data_dtor): New functions.
	(mi_out_new): Call mi_out_data_ctor.

testsuite/gdb/ChangeLog:

	* lib/gdb.exp (skip_python_tests_prompt): Renamed from
	skip_python_tests.  New arg prompt_regexp.
	(skip_python_tests): New function.
	* lib/mi-support.exp (mi_skip_python_tests): New function.
	* gdb.python/py-mi-objfile-gdb.py: New file.
	* gdb.python/py-mi-objfile.c: New file.
	* gdb.python/py-mi-objfile.exp: New file.

1 files changed, 69 insertions, 38 deletions

diff --git a/gdb/mi/mi-out.c b/gdb/mi/mi-out.c
index fa8282f..ef0a2df 100644
--- a/gdb/mi/mi-out.c
+++ b/gdb/mi/mi-out.c
@@ -22,19 +22,23 @@
 #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;
 
 /* These are the MI output functions */
 
+static void mi_out_data_dtor (struct ui_out *ui_out);
 static void mi_table_begin (struct ui_out *uiout, int nbrofcols,
 			    int nr_rows, const char *tblid);
 static void mi_table_body (struct ui_out *uiout);
@@ -85,7 +89,7 @@ static const struct ui_out_impl mi_ui_out_impl =
   mi_wrap_hint,
   mi_flush,
   mi_redirect,
-  0,
+  mi_out_data_dtor,
   1, /* Needs MI hacks.  */
 };
 
@@ -215,17 +219,19 @@ 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 +242,19 @@ 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 +283,9 @@ 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 +294,9 @@ 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 +309,31 @@ 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 +344,15 @@ 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 +366,9 @@ 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 +377,9 @@ 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.  */
@@ -380,9 +388,10 @@ void
 mi_out_put (struct ui_out *uiout, struct ui_file *stream)
 {
   mi_out_data *data = ui_out_data (uiout);
+  struct ui_file *outstream = VEC_last (ui_filep, data->streams);
 
-  ui_file_put (data->buffer, ui_file_write_for_put, stream);
-  ui_file_rewind (data->buffer);
+  ui_file_put (outstream, ui_file_write_for_put, stream);
+  ui_file_rewind (outstream);
 }
 
 /* Return the current MI version.  */
@@ -395,19 +404,41 @@ mi_version (struct ui_out *uiout)
   return data->mi_version;
 }
 
+/* Constructor for an `mi_out_data' object.  */
+
+static void
+mi_out_data_ctor (mi_out_data *self, int mi_version, struct ui_file *stream)
+{
+  gdb_assert (stream != NULL);
+
+  self->streams = NULL;
+  VEC_safe_push (ui_filep, self->streams, stream);
+
+  self->suppress_field_separator = 0;
+  self->suppress_output = 0;
+  self->mi_version = mi_version;
+}
+
+/* The destructor.  */
+
+static void
+mi_out_data_dtor (struct ui_out *ui_out)
+{
+  mi_out_data *data = ui_out_data (ui_out);
+
+  VEC_free (ui_filep, data->streams);
+  xfree (data);
+}
+
 /* Initialize private members at startup.  */
 
 struct ui_out *
 mi_out_new (int mi_version)
 {
   int flags = 0;
-
   mi_out_data *data = XNEW (mi_out_data);
-  data->suppress_field_separator = 0;
-  data->suppress_output = 0;
-  data->mi_version = mi_version;
-  /* FIXME: This code should be using a ``string_file'' and not the
-     TUI buffer hack. */
-  data->buffer = mem_fileopen ();
+  struct ui_file *stream = mem_fileopen ();
+
+  mi_out_data_ctor (data, mi_version, stream);
   return ui_out_new (&mi_ui_out_impl, data, flags);
 }