Have ptype handle types declared pragma Unchecked_Variants.

When a type is marked with pragma Unchecked_Variants, ptype did not print
variants having a single component, since the compiler produces incorrect
debugging output for such cases.  With this patch, we special-case these
components so that they print.

Changelog:

    * gdb/ada-typeprint.c (print_selected_record_field_types): New function,
    incorporating and generalizing print_record_field_types.
    (print_record_field_types): Change return value and update comment.
    Re-implement using print_selected_record_field_types.
    (print_choices): Print "=>" here.
    Handle case of unencoded variant branch.
    (print_variant_clauses): Reformat comment.
    Special-case unencoded variant branch.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 7a385fb155da1df557dc27f47f0b45f1e498cce2..61bdd5f8dbb2074043aeaf224dd2fb38741e98af 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,4 +1,15 @@
-2010-10-03  Paul Hilfinger  <hilfingr@syracuse.mckusick.com>
+2010-10-03  Paul Hilfinger  <hilfinger@adacore.com>
+
+        * gdb/ada-typeprint.c (print_selected_record_field_types): New function,
+        incorporating and generalizing print_record_field_types.
+        (print_record_field_types): Change return value and update comment.
+        Re-implement using print_selected_record_field_types.
+        (print_choices): Print "=>" here.
+        Handle case of unencoded variant branch.
+        (print_variant_clauses): Reformat comment.
+        Special-case unencoded variant branch.
+
+2010-10-03  Paul Hilfinger  <hilfinger@adacore.com>
 
         * ada-lang.c (wild_match): Reimplement.
         Change API to eliminate unused length argument, reverse arguments and

diff --git a/gdb/ada-typeprint.c b/gdb/ada-typeprint.c
index a02c8d4fece592530ad36f3533be13915649e138..6139edd3c99b2496c2ba7320b0a7666aabdbe07b 100644 (file)
--- a/gdb/ada-typeprint.c
+++ b/gdb/ada-typeprint.c
@@ -38,13 +38,17 @@
 #include "gdb_string.h"
 #include <errno.h>
 
+static int print_selected_record_field_types (struct type *, struct type *,
+                                             int, int,
+                                             struct ui_file *, int, int);
+   
 static int print_record_field_types (struct type *, struct type *,
                                     struct ui_file *, int, int);
 
 static void print_array_type (struct type *, struct ui_file *, int, int);
 
-static void print_choices (struct type *, int, struct ui_file *,
-                          struct type *);
+static int print_choices (struct type *, int, struct ui_file *,
+                         struct type *);
 
 static void print_range (struct type *, struct ui_file *);
 
@@ -397,9 +401,14 @@ print_array_type (struct type *type, struct ui_file *stream, int show,
 }
 
 /* Print the choices encoded by field FIELD_NUM of variant-part TYPE on
-   STREAM, assuming that VAL_TYPE (if non-NULL) is the type of the values.  */
+   STREAM, assuming that VAL_TYPE (if non-NULL) is the type of the
+   values. Returns non-zero if the field is an encoding of
+   discriminant values, as in a standard variant record, and 0 if the
+   field is not so encoded (as happens with single-component variants
+   in types annotated with pragma Unchecked_Variant.)
+ */
 
-static void
+static int
 print_choices (struct type *type, int field_num, struct ui_file *stream,
               struct type *val_type)
 {
@@ -423,7 +432,11 @@ print_choices (struct type *type, int field_num, struct ui_file *stream,
       switch (name[p])
        {
        default:
-         return;
+         goto Huh;
+       case '_':
+       case '\0':
+         fprintf_filtered (stream, " =>");
+         return 1;
        case 'S':
        case 'R':
        case 'O':
@@ -464,18 +477,17 @@ print_choices (struct type *type, int field_num, struct ui_file *stream,
     }
 
 Huh:
-  fprintf_filtered (stream, "??");
-
+  fprintf_filtered (stream, "?? =>");
+  return 0;
 }
 
-/* Assuming that field FIELD_NUM of TYPE is a VARIANTS field whose
-   discriminant is contained in OUTER_TYPE, print its variants on STREAM.
-   LEVEL is the recursion
-   (indentation) level, in case any of the fields themselves have
-   nested structure, and SHOW is the number of levels of internal structure
-   to show (see ada_print_type).  For this purpose, fields nested in a
-   variant part are taken to be at the same level as the fields
-   immediately outside the variant part.  */
+/* Assuming that field FIELD_NUM of TYPE represents variants whose
+   discriminant is contained in OUTER_TYPE, print its components on STREAM.
+   LEVEL is the recursion (indentation) level, in case any of the fields
+   themselves have nested structure, and SHOW is the number of levels of 
+   internal structure to show (see ada_print_type).  For this purpose,
+   fields nested in a variant part are taken to be at the same level as
+   the fields immediately outside the variant part.  */
 
 static void
 print_variant_clauses (struct type *type, int field_num,
@@ -503,11 +515,16 @@ print_variant_clauses (struct type *type, int field_num,
   for (i = 0; i < TYPE_NFIELDS (var_type); i += 1)
     {
       fprintf_filtered (stream, "\n%*swhen ", level + 4, "");
-      print_choices (var_type, i, stream, discr_type);
-      fprintf_filtered (stream, " =>");
-      if (print_record_field_types (TYPE_FIELD_TYPE (var_type, i),
-                                   outer_type, stream, show, level + 4) <= 0)
-       fprintf_filtered (stream, " null;");
+      if (print_choices (var_type, i, stream, discr_type))
+       {
+         if (print_record_field_types (TYPE_FIELD_TYPE (var_type, i),
+                                       outer_type, stream, show, level + 4) 
+             <= 0)
+           fprintf_filtered (stream, " null;");
+       }
+      else
+       print_selected_record_field_types (var_type, outer_type, i, i,
+                                          stream, show, level + 4);
     }
 }
 
@@ -531,28 +548,28 @@ print_variant_part (struct type *type, int field_num, struct type *outer_type,
   fprintf_filtered (stream, "\n%*send case;", level + 4, "");
 }
 
-/* Print a description on STREAM of the fields in record type TYPE, whose
-   discriminants are in OUTER_TYPE.  LEVEL is the recursion (indentation)
-   level, in case any of the fields themselves have nested structure,
-   and SHOW is the number of levels of internal structure to show
-   (see ada_print_type).  Does not print parent type information of TYPE.
-   Returns 0 if no fields printed, -1 for an incomplete type, else > 0.
-   Prints each field beginning on a new line, but does not put a new line at
-   end.  */
+/* Print a description on STREAM of the fields FLD0 through FLD1 in
+   record or union type TYPE, whose discriminants are in OUTER_TYPE.
+   LEVEL is the recursion (indentation) level, in case any of the
+   fields themselves have nested structure, and SHOW is the number of
+   levels of internal structure to show (see ada_print_type).  Does
+   not print parent type information of TYPE. Returns 0 if no fields
+   printed, -1 for an incomplete type, else > 0.  Prints each field
+   beginning on a new line, but does not put a new line at end.  */
 
 static int
-print_record_field_types (struct type *type, struct type *outer_type,
-                         struct ui_file *stream, int show, int level)
+print_selected_record_field_types (struct type *type, struct type *outer_type,
+                                  int fld0, int fld1,
+                                  struct ui_file *stream, int show, int level)
 {
-  int len, i, flds;
+  int i, flds;
 
   flds = 0;
-  len = TYPE_NFIELDS (type);
 
-  if (len == 0 && TYPE_STUB (type))
+  if (fld0 > fld1 && TYPE_STUB (type))
     return -1;
 
-  for (i = 0; i < len; i += 1)
+  for (i = fld0; i <= fld1; i += 1)
     {
       QUIT;
 
@@ -580,6 +597,19 @@ print_record_field_types (struct type *type, struct type *outer_type,
   return flds;
 }
 
+/* Print a description on STREAM of all fields of record or union type
+   TYPE, as for print_selected_record_field_types, above.  */
+
+static int
+print_record_field_types (struct type *type, struct type *outer_type,
+                         struct ui_file *stream, int show, int level)
+{
+  return print_selected_record_field_types (type, outer_type,
+                                           0, TYPE_NFIELDS (type) - 1,
+                                           stream, show, level);
+}
+   
+
 /* Print record type TYPE on STREAM.  LEVEL is the recursion (indentation)
    level, in case the element type itself has nested structure, and SHOW is
    the number of levels of internal structure to show (see ada_print_type).  */