[PATCH 2/2] Handle range types in ax-gdb.c

[Tom Tromey <tromey@adacore.com>]

A range type can usually be treated the same as its underlying integer
type, at least for the purposes of agent expressions.  This patch
arranges for range types to be handled this way in ax-gdb.c, letting a
somewhat larger subset of Ada expressions be compiled.
---
 gdb/ax-gdb.c                          | 60 +++++++++++++++++----------
 gdb/testsuite/gdb.ada/ax-ada.exp      |  1 +
 gdb/testsuite/gdb.ada/ax-ada/prog.adb |  3 ++
 3 files changed, 42 insertions(+), 22 deletions(-)

diff --git a/gdb/ax-gdb.c b/gdb/ax-gdb.c
index fc214e7dfe1..dc2c25410fe 100644
--- a/gdb/ax-gdb.c
+++ b/gdb/ax-gdb.c
@@ -353,6 +353,16 @@ gen_extend (struct agent_expr *ax, struct type *type)
   ((type->is_unsigned () ? ax_zero_ext : ax_ext) (ax, bits));
 }
 
+/* A helper that returns the target type if TYPE is a range type, or
+   otherwise just returns TYPE.  */
+
+static struct type *
+strip_range_type (struct type *type)
+{
+  if (type->code () == TYPE_CODE_RANGE)
+    return type->target_type ();
+  return type;
+}
 
 /* Assume that the top of the stack contains a value of type "pointer
    to TYPE"; generate code to fetch its value.  Note that TYPE is the
@@ -366,8 +376,7 @@ gen_fetch (struct agent_expr *ax, struct type *type)
       ax_trace_quick (ax, type->length ());
     }
 
-  if (type->code () == TYPE_CODE_RANGE)
-    type = type->target_type ();
+  type = strip_range_type (type);
 
   switch (type->code ())
     {
@@ -832,9 +841,12 @@ static void
 gen_usual_arithmetic (struct agent_expr *ax, struct axs_value *value1,
 		      struct axs_value *value2)
 {
+  struct type *type1 = strip_range_type (value1->type);
+  struct type *type2 = strip_range_type (value2->type);
+
   /* Do the usual binary conversions.  */
-  if (value1->type->code () == TYPE_CODE_INT
-      && value2->type->code () == TYPE_CODE_INT)
+  if (type1->code () == TYPE_CODE_INT
+      && type2->code () == TYPE_CODE_INT)
     {
       /* The ANSI integral promotions seem to work this way: Order the
 	 integer types by size, and then by signedness: an n-bit
@@ -842,18 +854,18 @@ gen_usual_arithmetic (struct agent_expr *ax, struct axs_value *value1,
 	 type.  Promote to the "wider" of the two types, and always
 	 promote at least to int.  */
       struct type *target = max_type (builtin_type (ax->gdbarch)->builtin_int,
-				      max_type (value1->type, value2->type));
+				      max_type (type1, type2));
 
       /* Deal with value2, on the top of the stack.  */
-      gen_conversion (ax, value2->type, target);
+      gen_conversion (ax, type2, target);
 
       /* Deal with value1, not on the top of the stack.  Don't
 	 generate the `swap' instructions if we're not actually going
 	 to do anything.  */
-      if (is_nontrivial_conversion (value1->type, target))
+      if (is_nontrivial_conversion (type1, target))
 	{
 	  ax_simple (ax, aop_swap);
-	  gen_conversion (ax, value1->type, target);
+	  gen_conversion (ax, type1, target);
 	  ax_simple (ax, aop_swap);
 	}
 
@@ -892,6 +904,7 @@ gen_cast (struct agent_expr *ax, struct axs_value *value, struct type *type)
   require_rvalue (ax, value);
   /* Dereference typedefs.  */
   type = check_typedef (type);
+  type = strip_range_type (type);
 
   switch (type->code ())
     {
@@ -960,7 +973,7 @@ gen_ptradd (struct agent_expr *ax, struct axs_value *value,
 	    struct axs_value *value1, struct axs_value *value2)
 {
   gdb_assert (value1->type->is_pointer_or_reference ());
-  gdb_assert (value2->type->code () == TYPE_CODE_INT);
+  gdb_assert (strip_range_type (value2->type)->code () == TYPE_CODE_INT);
 
   gen_scale (ax, aop_mul, value1->type);
   ax_simple (ax, aop_add);
@@ -976,7 +989,7 @@ gen_ptrsub (struct agent_expr *ax, struct axs_value *value,
 	    struct axs_value *value1, struct axs_value *value2)
 {
   gdb_assert (value1->type->is_pointer_or_reference ());
-  gdb_assert (value2->type->code () == TYPE_CODE_INT);
+  gdb_assert (strip_range_type (value2->type)->code () == TYPE_CODE_INT);
 
   gen_scale (ax, aop_mul, value1->type);
   ax_simple (ax, aop_sub);
@@ -1048,14 +1061,15 @@ gen_binop (struct agent_expr *ax, struct axs_value *value,
 	   int may_carry, const char *name)
 {
   /* We only handle INT op INT.  */
-  if ((value1->type->code () != TYPE_CODE_INT)
-      || (value2->type->code () != TYPE_CODE_INT))
+  struct type *type1 = strip_range_type (value1->type);
+  if ((type1->code () != TYPE_CODE_INT)
+      || (strip_range_type (value2->type)->code () != TYPE_CODE_INT))
     error (_("Invalid combination of types in %s."), name);
 
-  ax_simple (ax, value1->type->is_unsigned () ? op_unsigned : op);
+  ax_simple (ax, type1->is_unsigned () ? op_unsigned : op);
   if (may_carry)
-    gen_extend (ax, value1->type);	/* catch overflow */
-  value->type = value1->type;
+    gen_extend (ax, type1);	/* catch overflow */
+  value->type = type1;
   value->kind = axs_rvalue;
 }
 
@@ -1064,8 +1078,9 @@ static void
 gen_logical_not (struct agent_expr *ax, struct axs_value *value,
 		 struct type *result_type)
 {
-  if (value->type->code () != TYPE_CODE_INT
-      && value->type->code () != TYPE_CODE_PTR)
+  struct type *type = strip_range_type (value->type);
+  if (type->code () != TYPE_CODE_INT
+      && type->code () != TYPE_CODE_PTR)
     error (_("Invalid type of operand to `!'."));
 
   ax_simple (ax, aop_log_not);
@@ -1076,11 +1091,12 @@ gen_logical_not (struct agent_expr *ax, struct axs_value *value,
 static void
 gen_complement (struct agent_expr *ax, struct axs_value *value)
 {
-  if (value->type->code () != TYPE_CODE_INT)
+  struct type *type = strip_range_type (value->type);
+  if (type->code () != TYPE_CODE_INT)
     error (_("Invalid type of operand to `~'."));
 
   ax_simple (ax, aop_bit_not);
-  gen_extend (ax, value->type);
+  gen_extend (ax, type);
 }
 \f
 
@@ -2078,7 +2094,7 @@ gen_expr_binop_rest (struct expression *exp,
   switch (op)
     {
     case BINOP_ADD:
-      if (value1->type->code () == TYPE_CODE_INT
+      if (strip_range_type (value1->type)->code () == TYPE_CODE_INT
 	  && value2->type->is_pointer_or_reference ())
 	{
 	  /* Swap the values and proceed normally.  */
@@ -2086,7 +2102,7 @@ gen_expr_binop_rest (struct expression *exp,
 	  gen_ptradd (ax, value, value2, value1);
 	}
       else if (value1->type->is_pointer_or_reference ()
-	       && value2->type->code () == TYPE_CODE_INT)
+	       && strip_range_type (value2->type)->code () == TYPE_CODE_INT)
 	gen_ptradd (ax, value, value1, value2);
       else
 	gen_binop (ax, value, value1, value2,
@@ -2094,7 +2110,7 @@ gen_expr_binop_rest (struct expression *exp,
       break;
     case BINOP_SUB:
       if (value1->type->is_pointer_or_reference ()
-	  && value2->type->code () == TYPE_CODE_INT)
+	  && strip_range_type (value2->type)->code () == TYPE_CODE_INT)
 	gen_ptrsub (ax,value, value1, value2);
       else if (value1->type->is_pointer_or_reference ()
 	       && value2->type->is_pointer_or_reference ())
diff --git a/gdb/testsuite/gdb.ada/ax-ada.exp b/gdb/testsuite/gdb.ada/ax-ada.exp
index b08f7c4362c..d0464b7a5b8 100644
--- a/gdb/testsuite/gdb.ada/ax-ada.exp
+++ b/gdb/testsuite/gdb.ada/ax-ada.exp
@@ -29,3 +29,4 @@ set bp_location [gdb_get_line_number "START" ${testdir}/prog.adb]
 runto "prog.adb:$bp_location"
 
 gdb_test "maint agent-eval variable = 23" ".*end"
+gdb_test "maint agent-eval range_variable = 23" ".*end"
diff --git a/gdb/testsuite/gdb.ada/ax-ada/prog.adb b/gdb/testsuite/gdb.ada/ax-ada/prog.adb
index 3852711e88c..85148d0c9c5 100644
--- a/gdb/testsuite/gdb.ada/ax-ada/prog.adb
+++ b/gdb/testsuite/gdb.ada/ax-ada/prog.adb
@@ -14,7 +14,10 @@
 --  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 procedure Prog is
+   type Range_Type is range -15 .. 73;
+
    Variable : Integer := 23;
+   Range_Variable : Range_Type := 23;
 begin
    null; -- START
 end Prog;
-- 
2.38.1