2001-11-06 Pierre Muller <muller@ics.u-strasbg.fr>

	* p-lang.c (is_pascal_string_type): New function to determine if a
	type is a string type.
	* p-lang.h: Add prototype for is_pascal_string_type.
	* p-valprint.c (pascal_val_print) : Use is_pascal_string_type function
	to display strings nicely.

4 files changed, 78 insertions, 18 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index db07d6c..940c06b 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,13 @@
 2001-11-06 Pierre Muller  <muller@ics.u-strasbg.fr>
 
+	* p-lang.c (is_pascal_string_type): New function to determine if a 
+	type is a string type.
+	* p-lang.h: Add prototype for is_pascal_string_type.
+	* p-valprint.c (pascal_val_print) : Use is_pascal_string_type function 
+	to display strings nicely.
+
+2001-11-06 Pierre Muller  <muller@ics.u-strasbg.fr>
+
 	* p-exp.y (yylex): Only change case of expression if symbol is found.
 	Also check for GPC standard name form.
 
diff --git a/gdb/p-lang.c b/gdb/p-lang.c
index 93dd254..b5ad580 100644
--- a/gdb/p-lang.c
+++ b/gdb/p-lang.c
@@ -17,7 +17,7 @@
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
 
-/* This file is derived from p-lang.c */
+/* This file is derived from c-lang.c */
 
 #include "defs.h"
 #include "symtab.h"
@@ -27,8 +27,56 @@
 #include "language.h"
 #include "p-lang.h"
 #include "valprint.h"
-
+#include <ctype.h>
+ 
 extern void _initialize_pascal_language (void);
+
+
+/* Determines if type TYPE is a pascal string type.
+   Returns 1 if the type is a known pascal type
+   This function is used by p-valprint.c code to allow better string display.
+   If it is a pascal string type, then it also sets info needed
+   to get the length and the data of the string
+   length_pos, length_size and string_pos are given in bytes.
+   char_size gives the element size in bytes.
+   FIXME: if the position or the size of these fields
+   are not multiple of TARGET_CHAR_BIT then the results are wrong
+   but this does not happen for Free Pascal nor for GPC.  */
+int
+is_pascal_string_type (struct type *type,int *length_pos,
+                       int * length_size, int *string_pos, int *char_size)
+{
+  if (TYPE_CODE (type) == TYPE_CODE_STRUCT)
+    {
+      /* Old Borland type pascal strings from Free Pascal Compiler.  */
+      /* Two fields: length and st.  */
+      if (TYPE_NFIELDS (type) == 2 
+          && strcmp (TYPE_FIELDS (type)[0].name, "length") == 0 
+          && strcmp (TYPE_FIELDS (type)[1].name, "st") == 0)
+        {
+          *length_pos = TYPE_FIELD_BITPOS (type, 0) / TARGET_CHAR_BIT;
+          *length_size = TYPE_FIELD_TYPE (type, 0)->length;
+          *string_pos = TYPE_FIELD_BITPOS (type, 1) / TARGET_CHAR_BIT;
+          *char_size = 1;
+          return 1;
+        };
+      /* GNU pascal strings.  */
+      /* Three fields: Capacity, length and schema$ or _p_schema.  */
+      if (TYPE_NFIELDS (type) == 3
+          && strcmp (TYPE_FIELDS (type)[0].name, "Capacity") == 0
+          && strcmp (TYPE_FIELDS (type)[1].name, "length") == 0)
+        {
+          *length_pos = TYPE_FIELD_BITPOS (type, 1) / TARGET_CHAR_BIT;
+          *length_size = TYPE_FIELD_TYPE (type, 1)->length;
+          *string_pos = TYPE_FIELD_BITPOS (type, 2) / TARGET_CHAR_BIT;
+          /* FIXME: how can I detect wide chars in GPC ?? */
+          *char_size = 1;
+          return 1;
+        };
+    }
+  return 0;
+}
+
 static void pascal_one_char (int, struct ui_file *, int *);
 
 /* Print the character C on STREAM as part of the contents of a literal
diff --git a/gdb/p-lang.h b/gdb/p-lang.h
index 3dd2830..ca8a0a9 100644
--- a/gdb/p-lang.h
+++ b/gdb/p-lang.h
@@ -38,6 +38,8 @@ extern void pascal_type_print_method_args (char *, char *,
 
 /* These are in p-lang.c: */
 
+extern int is_pascal_string_type (struct type *, int *, int *, int *, int*);
+
 extern void pascal_printchar (int, struct ui_file *);
 
 extern void pascal_printstr (struct ui_file *, char *, unsigned int, int, int);
diff --git a/gdb/p-valprint.c b/gdb/p-valprint.c
index 275427b..78b941a 100644
--- a/gdb/p-valprint.c
+++ b/gdb/p-valprint.c
@@ -63,6 +63,8 @@ pascal_val_print (struct type *type, char *valaddr, int embedded_offset,
   unsigned len;
   struct type *elttype;
   unsigned eltlen;
+  int length_pos, length_size, string_pos;
+  int char_size;
   LONGEST val;
   CORE_ADDR addr;
 
@@ -187,16 +189,17 @@ pascal_val_print (struct type *type, char *valaddr, int embedded_offset,
 	     as GDB does not recognize stabs pascal strings
 	     Pascal strings are mapped to records
 	     with lowercase names PM  */
-	  /* I don't know what GPC does :( PM */
-	  if (TYPE_CODE (elttype) == TYPE_CODE_STRUCT &&
-	      TYPE_NFIELDS (elttype) == 2 &&
-	      strcmp (TYPE_FIELDS (elttype)[0].name, "length") == 0 &&
-	      strcmp (TYPE_FIELDS (elttype)[1].name, "st") == 0 &&
-	      addr != 0)
+          if (is_pascal_string_type (elttype, &length_pos,
+                                     &length_size, &string_pos, &char_size)
+	      && addr != 0)
 	    {
-	      char bytelength;
-	      read_memory (addr, &bytelength, 1);
-	      i = val_print_string (addr + 1, bytelength, 1, stream);
+	      ULONGEST string_length;
+              void *buffer;
+              buffer = xmalloc (length_size);
+              read_memory (addr + length_pos, buffer, length_size);
+	      string_length = extract_unsigned_integer (buffer, length_size);
+              xfree (buffer);
+              i = val_print_string (addr + string_pos, string_length, char_size, stream);
 	    }
 	  else if (pascal_object_is_vtbl_member (type))
 	    {
@@ -205,8 +208,8 @@ pascal_val_print (struct type *type, char *valaddr, int embedded_offset,
 
 	      struct minimal_symbol *msymbol =
 	      lookup_minimal_symbol_by_pc (vt_address);
-	      if ((msymbol != NULL) &&
-		  (vt_address == SYMBOL_VALUE_ADDRESS (msymbol)))
+	      if ((msymbol != NULL)
+		  && (vt_address == SYMBOL_VALUE_ADDRESS (msymbol)))
 		{
 		  fputs_filtered (" <", stream);
 		  fputs_filtered (SYMBOL_SOURCE_NAME (msymbol), stream);
@@ -315,12 +318,11 @@ pascal_val_print (struct type *type, char *valaddr, int embedded_offset,
 	}
       else
 	{
-	  if ((TYPE_NFIELDS (type) == 2) &&
-	      (strcmp (TYPE_FIELDS (type)[0].name, "length") == 0) &&
-	      (strcmp (TYPE_FIELDS (type)[1].name, "st") == 0))
+          if (is_pascal_string_type (type, &length_pos, &length_size,
+                                     &string_pos, &char_size))
 	    {
-	      len = (*(valaddr + embedded_offset)) & 0xff;
-	      LA_PRINT_STRING (stream, valaddr + embedded_offset + 1, len, /* width ?? */ 0, 0);
+	      len = extract_unsigned_integer (valaddr + embedded_offset + length_pos, length_size);
+	      LA_PRINT_STRING (stream, valaddr + embedded_offset + string_pos, len, char_size, 0);
 	    }
 	  else
 	    pascal_object_print_value_fields (type, valaddr + embedded_offset, address, stream, format,