[rfc][15/37] Eliminate builtin_type_ macros: Dereferencing of integer types

[uweigand@de.ibm.com]

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Hello,

GDB allows to dereference an integer type, treating it as if it were
an "int *".  This patch pulls support for this special extension out
of common value_ind code (which doesn't know which architecture to
use for that "int" type) and into the expression evaluators -- which
already handle it for the EVAL_AVOID_SIDE_EFFECTS case.

It might make sense to check for which languages this extension
is actually useful, and remove it from the rest.

Bye,
Ulrich


ChangeLog:

	* valops.c (value_ind): No longer allow dereferencing an
	integer type.
	* eval.c (evaluate_subexp_standard): Handle deferencing an
	integer type here.
	* ada-lang.c (ada_evaluate_subexp): Likewise.
	* jv-lang.c (evaluate_subexp_java): Likewise.


Index: gdb-head/gdb/ada-lang.c
===================================================================
--- gdb-head.orig/gdb/ada-lang.c
+++ gdb-head/gdb/ada-lang.c
@@ -9194,7 +9194,8 @@ ada_evaluate_subexp (struct type *expect
             }
           else if (TYPE_CODE (type) == TYPE_CODE_INT)
             /* GDB allows dereferencing an int.  */
-            return value_zero (builtin_type_int, lval_memory);
+            return value_zero (builtin_type (exp->gdbarch)->builtin_int,
+			       lval_memory);
           else
             error (_("Attempt to take contents of a non-pointer value."));
         }
@@ -9204,6 +9205,10 @@ ada_evaluate_subexp (struct type *expect
       if (ada_is_array_descriptor_type (type))
         /* GDB allows dereferencing GNAT array descriptors.  */
         return ada_coerce_to_simple_array (arg1);
+      else if (TYPE_CODE (type) == TYPE_CODE_INT)
+	/* GDB allows dereferencing an int.  */
+	return value_at_lazy (builtin_type (exp->gdbarch)->builtin_int,
+			      (CORE_ADDR) value_as_address (arg1));
       else
         return ada_value_ind (arg1);
 
Index: gdb-head/gdb/eval.c
===================================================================
--- gdb-head.orig/gdb/eval.c
+++ gdb-head/gdb/eval.c
@@ -2288,10 +2288,19 @@ evaluate_subexp_standard (struct type *e
 			       lval_memory);
 	  else if (TYPE_CODE (type) == TYPE_CODE_INT)
 	    /* GDB allows dereferencing an int.  */
-	    return value_zero (builtin_type_int, lval_memory);
+	    return value_zero (builtin_type (exp->gdbarch)->builtin_int,
+			       lval_memory);
 	  else
 	    error (_("Attempt to take contents of a non-pointer value."));
 	}
+
+      /* Allow * on an integer so we can cast it to whatever we want.
+	 This returns an int, which seems like the most C-like thing to
+	 do.  "long long" variables are rare enough that
+	 BUILTIN_TYPE_LONGEST would seem to be a mistake.  */
+      if (TYPE_CODE (type) == TYPE_CODE_INT)
+	return value_at_lazy (builtin_type (exp->gdbarch)->builtin_int,
+			      (CORE_ADDR) value_as_address (arg1));
       return value_ind (arg1);
 
     case UNOP_ADDR:
Index: gdb-head/gdb/jv-lang.c
===================================================================
--- gdb-head.orig/gdb/jv-lang.c
+++ gdb-head/gdb/jv-lang.c
@@ -855,6 +855,10 @@ evaluate_subexp_java (struct type *expec
 	}
       if (noside == EVAL_SKIP)
 	goto nosideret;
+      if (TYPE_CODE (value_type (arg1)) == TYPE_CODE_INT)
+        /* GDB allows dereferencing an int.  */
+        return value_at_lazy (builtin_type (exp->gdbarch)->builtin_int,
+                              (CORE_ADDR) value_as_address (arg1));
       return value_ind (arg1);
 
     case BINOP_SUBSCRIPT:
Index: gdb-head/gdb/valops.c
===================================================================
--- gdb-head.orig/gdb/valops.c
+++ gdb-head/gdb/valops.c
@@ -1166,14 +1166,7 @@ value_ind (struct value *arg1)
 
   base_type = check_typedef (value_type (arg1));
 
-  /* Allow * on an integer so we can cast it to whatever we want.
-     This returns an int, which seems like the most C-like thing to
-     do.  "long long" variables are rare enough that
-     BUILTIN_TYPE_LONGEST would seem to be a mistake.  */
-  if (TYPE_CODE (base_type) == TYPE_CODE_INT)
-    return value_at_lazy (builtin_type_int,
-			  (CORE_ADDR) value_as_address (arg1));
-  else if (TYPE_CODE (base_type) == TYPE_CODE_PTR)
+  if (TYPE_CODE (base_type) == TYPE_CODE_PTR)
     {
       struct type *enc_type;
       /* We may be pointing to something embedded in a larger object.

-- 
  Dr. Ulrich Weigand
  GNU Toolchain for Linux on System z and Cell BE
  Ulrich.Weigand@de.ibm.com