[wasm] Base address for data segments can also be the value of a global variable.

test/mjsunit/wasm/data-segments.js

+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --expose-wasm
+
+load("test/mjsunit/wasm/wasm-constants.js");
+load("test/mjsunit/wasm/wasm-module-builder.js");
+
+var debug = false;
+
+function SimpleDataSegmentTest(offset) {
+  print("SimpleDataSegmentTest(" + offset + ")...");
+  var builder = new WasmModuleBuilder();
+  builder.addMemory(1, 1, false);
+  builder.addFunction("load", kSig_i_i)
+    .addBody([kExprGetLocal, 0, kExprI32LoadMem, 0, 0])
+    .exportAs("load");
+  builder.addDataSegment(offset, [9, 9, 9, 9]);
+
+  var buffer = builder.toBuffer(debug);
+  var instance = Wasm.instantiateModule(buffer);
+  for (var i = offset - 20; i < offset + 20; i += 4) {
+    if (i < 0) continue;
+    var expected = (i == offset) ? 151587081 : 0;
+    assertEquals(expected, instance.exports.load(i));
+  }
+}
+
+SimpleDataSegmentTest(0);
+SimpleDataSegmentTest(4);
+SimpleDataSegmentTest(12);
+SimpleDataSegmentTest(1064);
+
+function GlobalInitTest(offset) {
+  print("GlobalInitTest(" + offset + ")...");
+  var builder = new WasmModuleBuilder();
+  builder.addMemory(1, 1, false);
+  var g = builder.addGlobal(kAstI32, false);
+  g.init = offset;
+  builder.addFunction("load", kSig_i_i)
+    .addBody([kExprGetLocal, 0, kExprI32LoadMem, 0, 0])
+    .exportAs("load");
+  builder.addDataSegment(g.index, [7, 7, 7, 7], true);
+
+  var buffer = builder.toBuffer(debug);
+  var instance = Wasm.instantiateModule(buffer);
+  for (var i = offset - 20; i < offset + 20; i += 4) {
+    if (i < 0) continue;
+    var expected = i == offset ? 117901063 : 0;
+    assertEquals(expected, instance.exports.load(i));
+  }
+}
+
+GlobalInitTest(0);
+GlobalInitTest(12);
+GlobalInitTest(3040);
+
+function GlobalImportedInitTest(pad) {
+  print("GlobaleImportedInitTest(" + pad + ")...");
+  var builder = new WasmModuleBuilder();
+  builder.addMemory(1, 1, false);
+
+  while (pad-- > 0) builder.addGlobal(kAstI32);  // pad
+
+  var g = builder.addImportedGlobal("offset", undefined, kAstI32);
+
+  while (pad-- > 0) builder.addGlobal(kAstI32);  // pad
+
+  builder.addFunction("load", kSig_i_i)
+    .addBody([kExprGetLocal, 0, kExprI32LoadMem, 0, 0])
+    .exportAs("load");
+  builder.addDataSegment(g.index, [5, 5, 5, 5], true);
+
+  var buffer = builder.toBuffer(debug);
+  var module = new WebAssembly.Module(buffer);
+
+  for (var offset of [0, 12, 192, 1024]) {
+    var instance = new WebAssembly.Instance(module, {offset: offset});
+    for (var i = offset - 20; i < offset + 20; i += 4) {
+      if (i < 0) continue;
+      var expected = i == offset ? 84215045 : 0;
+      assertEquals(expected, instance.exports.load(i));
+    }
+  }
+}
+
+GlobalImportedInitTest(0);
+GlobalImportedInitTest(1);
+GlobalImportedInitTest(4);