Revert "Revert "regent: Allow r.volume on regions.""

This reverts commit e237d08.

language/src/regent/ast_util.t

@@ -57,7 +57,8 @@ function ast_util.mk_expr_bounds_access(value)
   local expr_type = std.as_read(value.expr_type)
   local index_type
   if std.is_region(expr_type) then
-    index_type = expr_type:ispace().index_type
+    return ast_util.mk_expr_bounds_access(
+      ast_util.mk_expr_field_access(value, "ispace", expr_type:ispace()))
   elseif std.is_ispace(expr_type) then
     index_type = expr_type.index_type
   else

language/src/regent/codegen.t

@@ -2047,17 +2047,11 @@ function codegen.expr_field_access(cx, node)
         `([expr_type] { impl = [value.value].impl.index_space }),
         expr_type),
       expr_type)
-  elseif (std.is_ispace(value_type) or std.is_region(value_type)) and
-         field_name == "bounds" then
+  elseif std.is_ispace(value_type) and field_name == "bounds" then
     local value = codegen.expr(cx, node.value):read(cx)
     local expr_type = std.as_read(node.expr_type)
     assert(expr_type.is_rect_type)
-    local bounds
-    if std.is_ispace(value_type) then
-      bounds = cx:ispace(value_type).bounds
-    else
-      bounds = cx:ispace(value_type:ispace()).bounds
-    end
+    local bounds = cx:ispace(value_type).bounds
 
     local actions = quote
       [value.actions]

language/src/regent/parallelize_tasks.t

@@ -2301,10 +2301,12 @@ local function rewrite_metadata_access(task_cx)
   return function(node, continuation)
     if node:is(ast.typed.expr.FieldAccess) and
        node.field_name == "bounds" and
-       std.is_region(std.as_read(node.value.expr_type)) then
-      assert(node.value:is(ast.typed.expr.ID))
+       node.value:is(ast.typed.expr.FieldAccess) and 
+       node.value.field_name == "ispace" and
+       std.is_region(std.as_read(node.value.value.expr_type)) then
+      assert(node.value.value:is(ast.typed.expr.ID))
       local metadata_params =
-        task_cx:find_metadata_parameters(node.value.value)
+        task_cx:find_metadata_parameters(node.value.value.value)
       if metadata_params then
         return ast_util.mk_expr_id(metadata_params.bounds)
       else

language/src/regent/type_check.t

@@ -547,13 +547,18 @@ function type_check.expr_field_access(cx, node)
   elseif std.is_ispace(std.as_read(unpack_type)) and node.field_name == "volume" then
     -- Volume can be retrieved on any ispace.
     field_type = int64
-  elseif std.is_region(std.as_read(unpack_type)) and node.field_name == "bounds" then
-    local index_type = std.as_read(unpack_type):ispace().index_type
-    if index_type:is_opaque() then
-      report.error(node, "no field '" .. node.field_name .. "' in type " ..
-                  tostring(std.as_read(unpack_type)))
-    end
-    field_type = std.rect_type(index_type)
+  elseif std.is_region(std.as_read(unpack_type)) and (node.field_name == "bounds" or node.field_name == "volume") then
+    -- Index space fields can also be retrieved through a region.
+    return type_check.expr(
+      cx,
+      node {
+        value = ast.specialized.expr.FieldAccess {
+          value = node.value,
+          field_name = "ispace",
+          span = node.value.span,
+          annotations = node.value.annotations,
+        }
+      })
   elseif std.is_partition(std.as_read(unpack_type)) and node.field_name == "colors" then
     field_type = std.as_read(unpack_type):colors()
   elseif std.type_is_opaque_to_field_accesses(std.as_read(unpack_type)) then

language/tests/regent/compile_fail/invalid_bounds2.rg

@@ -13,7 +13,7 @@
 -- limitations under the License.
 
 -- fails-with:
--- invalid_bounds2.rg:27: no field 'bounds' in type region(int32)
+-- invalid_bounds2.rg:27: no field 'bounds' in type ispace(ptr)
 --   var bounds = r.bounds
 --                 ^
 

language/tests/regent/run_pass/region_volume.rg

@@ -0,0 +1,33 @@
+-- Copyright 2018 Stanford University
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+--     http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+
+import "regent"
+
+local c = regentlib.c
+
+task main()
+  var is = ispace(int2d, {4, 8})
+  var r = region(is, int)
+  var p = partition(equal, r, ispace(int2d, {2, 2}))
+  var r00 = p[{0, 0}]
+  var r11 = p[{1, 1}]
+  var r_volume = r.volume
+  var r00_volume = r00.volume
+  var r11_volume = r11.volume
+
+  regentlib.assert(r_volume == 32, "test failed")
+  regentlib.assert(r00_volume == 8, "test failed")
+  regentlib.assert(r11_volume == 8, "test failed")
+end
+regentlib.start(main)