PATCH: Add type_sprint() function to return type in string form

[Jason Molenda <jason-swarelist@molenda.com>]

[-- Attachment #1: Type: text/plain, Size: 1859 bytes --]

There are a few places in gdb where code prints an error message
with a type included in it.  The only way for these functions to
print a type is with type_print(), which takes a ui_file stream to
print its output to.  This means they either have to send the output
to gdb_stderr, or build up a fake memory ui_file and retrieve the
contents.

This patch adds a type_sprint() which does the latter and returns the
xmalloc()'ed string.

The current code gives bogus data to an MI client.  We had a bug that
gave this output at Apple:

-> 64-var-list-children "var7" 2
<- 64^error,msg="."
-> 65-exec-status
<- (gdb) 
<- &"Type TWindow has no component named TWindow"
<- 65^done,status="stopped"

This happens because this particular error reporter looked like this:

  fprintf_unfiltered (gdb_stderr, "Type ");
  type_print (type, "", gdb_stderr, -1);
  fprintf_unfiltered (gdb_stderr, " has no component named ");
  fputs_filtered (name, gdb_stderr);
  error (".");

Similar code shows up in a few places, so it made sense to create a 
single function to format a type into a string and return the string.

I can drop the ada-lang.c part of the patch if that will complicate
the approval, but given that this code is clearly derived from
gdbtypes.c, I don't think the change is particularly controversial.

This patch adds no new testsuite failures on RHL7.1 (gcc 2.96, stabs).

2003-04-18  Jason Molenda  (jmolenda @ apple.com)

        * typeprint.c (type_sprint): New function to return string form
        of types.  Use as type_print, sans a stream.
        * value.h (type_sprint): Add prototype.
        * ada-lang.c (ada_lookup_struct_elt_type): Use type_sprint() when
        building error message.
        * gdbtypes.c (lookup_struct_elt_type): Ditto.
        * varobj.c (varobj_get_type): Use type_sprint() to get the type
        in a string form.

[-- Attachment #2: pa.txt --]
[-- Type: text/plain, Size: 6433 bytes --]

Index: ChangeLog
===================================================================
RCS file: /cvs/src/src/gdb/ChangeLog,v
retrieving revision 1.4107
diff -u -p -r1.4107 ChangeLog
--- ChangeLog	18 Apr 2003 20:20:21 -0000	1.4107
+++ ChangeLog	18 Apr 2003 22:15:24 -0000
@@ -1,3 +1,14 @@
+2003-04-18  Jason Molenda  (jmolenda@apple.com)
+
+	* typeprint.c (type_sprint): New function to return string form
+	of types.  Use as type_print, sans a stream.
+	* value.h (type_sprint): Add prototype.
+	* ada-lang.c (ada_lookup_struct_elt_type): Use type_sprint() when
+	building error message.
+	* gdbtypes.c (lookup_struct_elt_type): Ditto.
+	* varobj.c (varobj_get_type): Use type_sprint() to get the type
+	in a string form.
+
 2003-04-18  Jim Blandy  <jimb@redhat.com>
 
 	* s390-tdep.c (s390_frame_align): New function.
Index: ada-lang.c
===================================================================
RCS file: /cvs/src/src/gdb/ada-lang.c,v
retrieving revision 1.23
diff -u -p -r1.23 ada-lang.c
--- ada-lang.c	2 Apr 2003 03:02:46 -0000	1.23
+++ ada-lang.c	18 Apr 2003 22:15:24 -0000
@@ -5610,6 +5610,7 @@ ada_lookup_struct_elt_type (struct type 
 			    int *dispp)
 {
   int i;
+  char *type_for_printing;
 
   if (name == NULL)
     goto BadName;
@@ -5628,9 +5629,9 @@ ada_lookup_struct_elt_type (struct type 
     {
       target_terminal_ours ();
       gdb_flush (gdb_stdout);
-      fprintf_unfiltered (gdb_stderr, "Type ");
-      type_print (type, "", gdb_stderr, -1);
-      error (" is not a structure or union type");
+      type_for_printing = type_sprint (type, "", -1);
+      make_cleanup (xfree, type_for_printing);
+      error ("Type %s is not a structure or union type", type_for_printing);
     }
 
   type = to_static_fixed_type (type);
@@ -5690,10 +5691,10 @@ BadName:
     {
       target_terminal_ours ();
       gdb_flush (gdb_stdout);
-      fprintf_unfiltered (gdb_stderr, "Type ");
-      type_print (type, "", gdb_stderr, -1);
-      fprintf_unfiltered (gdb_stderr, " has no component named ");
-      error ("%s", name == NULL ? "<null>" : name);
+      type_for_printing = type_sprint (type, "", -1);
+      make_cleanup (xfree, type_for_printing);
+      error ("Type %s has no component named %s", type_for_printing, 
+             name == NULL ? "<null>" : name);
     }
 
   return NULL;
Index: gdbtypes.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbtypes.c,v
retrieving revision 1.71
diff -u -p -r1.71 gdbtypes.c
--- gdbtypes.c	7 Feb 2003 21:44:00 -0000	1.71
+++ gdbtypes.c	18 Apr 2003 22:15:25 -0000
@@ -1218,6 +1218,7 @@ struct type *
 lookup_struct_elt_type (struct type *type, char *name, int noerr)
 {
   int i;
+  char *type_for_printing;
 
   for (;;)
     {
@@ -1233,9 +1234,9 @@ lookup_struct_elt_type (struct type *typ
     {
       target_terminal_ours ();
       gdb_flush (gdb_stdout);
-      fprintf_unfiltered (gdb_stderr, "Type ");
-      type_print (type, "", gdb_stderr, -1);
-      error (" is not a structure or union type.");
+      type_for_printing = type_sprint (type, "", -1);
+      make_cleanup (xfree, type_for_printing);
+      error ("Type %s is not a structure or union type.", type_for_printing);
     }
 
 #if 0
@@ -1281,11 +1282,10 @@ lookup_struct_elt_type (struct type *typ
 
   target_terminal_ours ();
   gdb_flush (gdb_stdout);
-  fprintf_unfiltered (gdb_stderr, "Type ");
-  type_print (type, "", gdb_stderr, -1);
-  fprintf_unfiltered (gdb_stderr, " has no component named ");
-  fputs_filtered (name, gdb_stderr);
-  error (".");
+  type_for_printing = type_sprint (type, "", -1); 
+  make_cleanup (xfree, type_for_printing);
+  error ("Type %s has no component named %s.", type_for_printing, name);
+
   return (struct type *) -1;	/* For lint */
 }
 
Index: typeprint.c
===================================================================
RCS file: /cvs/src/src/gdb/typeprint.c,v
retrieving revision 1.17
diff -u -p -r1.17 typeprint.c
--- typeprint.c	25 Feb 2003 21:36:21 -0000	1.17
+++ typeprint.c	18 Apr 2003 22:15:25 -0000
@@ -109,6 +109,27 @@ type_print (struct type *type, char *var
   LA_PRINT_TYPE (type, varstring, stream, show, 0);
 }
 
+/* Returns a xmalloc'ed string of the type name instead of printing it
+   to STREAM.  */
+
+char *
+type_sprint (struct type *type, char *varstring, int show)
+{
+  struct ui_file *stb;
+  struct cleanup *wipe;
+  long length;
+  char *type_name;
+  
+  stb = mem_fileopen ();
+  wipe = make_cleanup_ui_file_delete (stb);
+
+  type_print (type, varstring, stb, show);
+  type_name = ui_file_xstrdup (stb, &length);
+  do_cleanups (wipe);
+
+  return type_name;
+}
+
 /* Print type of EXP, or last thing in value history if EXP == NULL.
    show is passed to type_print.  */
 
Index: value.h
===================================================================
RCS file: /cvs/src/src/gdb/value.h,v
retrieving revision 1.45
diff -u -p -r1.45 value.h
--- value.h	12 Apr 2003 17:41:26 -0000	1.45
+++ value.h	18 Apr 2003 22:15:25 -0000
@@ -498,6 +498,8 @@ extern void modify_field (char *addr, LO
 extern void type_print (struct type * type, char *varstring,
 			struct ui_file * stream, int show);
 
+extern char *type_sprint (struct type *type, char *varstring, int show);
+
 extern char *baseclass_addr (struct type *type, int index, char *valaddr,
 			     struct value **valuep, int *errp);
 
Index: varobj.c
===================================================================
RCS file: /cvs/src/src/gdb/varobj.c,v
retrieving revision 1.38
diff -u -p -r1.38 varobj.c
--- varobj.c	4 Dec 2002 00:05:54 -0000	1.38
+++ varobj.c	18 Apr 2003 22:15:25 -0000
@@ -728,27 +728,17 @@ char *
 varobj_get_type (struct varobj *var)
 {
   struct value *val;
-  struct cleanup *old_chain;
-  struct ui_file *stb;
-  char *thetype;
-  long length;
 
   /* For the "fake" variables, do not return a type. (It's type is
      NULL, too.) */
   if (CPLUS_FAKE_CHILD (var))
     return NULL;
 
-  stb = mem_fileopen ();
-  old_chain = make_cleanup_ui_file_delete (stb);
-
   /* To print the type, we simply create a zero ``struct value *'' and
      cast it to our type. We then typeprint this variable. */
   val = value_zero (var->type, not_lval);
-  type_print (VALUE_TYPE (val), "", stb, -1);
 
-  thetype = ui_file_xstrdup (stb, &length);
-  do_cleanups (old_chain);
-  return thetype;
+  return (type_sprint (VALUE_TYPE (val), "",  -1));
 }
 
 enum varobj_languages