[wasm] Store the function_index in the js-to-wasm wrapper instead of the export index

test/mjsunit/wasm/test-import-export-wrapper.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 --allow-natives-syntax
 
 load("test/mjsunit/wasm/wasm-constants.js");
 load("test/mjsunit/wasm/wasm-module-builder.js");
 
 var expect_elison = 0;
@@ skipping 48 matching lines @@
     var the_export = first_module
         .instantiate({import_module_1: {import_name_1: f}})
         .exports.first_export;
     assertEquals(the_export(2), 3);
     assertEquals(the_export(-1), 0);
     assertEquals(the_export(0), 1);
     assertEquals(the_export(5.5), 6);
     assertEquals(%CheckWasmWrapperElision(the_export, expect_elison), true);
 })();
 
+// Function calls stack: first_export -> first_func -> first_import ->
+// second_export -> second_import
+// In this case, first_import and second_export have same signature,
+// So that wrappers will be removed. If the wrappers do are not removed, then

[Mircea Trofin, 2016/11/03 14:38:29]

remove "do" (If the wrappers...)

[ahaas, 2016/11/07 08:10:51]

I fixed it in https://codereview.chromium.org/2481133002

+// the test crashes because of the int64 parameter, which is not allowed in the

[Mircea Trofin, 2016/11/03 14:38:29]

while at it - the test fails, right? (OK, maybe it crashes as a form of failure,
but that's what we want in that case, right?)

[ahaas, 2016/11/07 08:10:51]

I do not understand your question. This test would fail without the changes to
wasm-module.cc, but with the changes it does not fail. Without changes the test
would fail with a runtime error.

+// wrappers.
+(function TestWasmWrapperElisionInt64() {
+ var imported = function (a) {
+     return a;
+ };
+
+ var second_module = new WasmModuleBuilder();
+ var sig_index1 = second_module.addType(kSig_i_i);
+ var sig_index_ll = second_module.addType(kSig_l_l);
+ second_module
+     .addImportWithModule("import_module_2", "import_name_2", sig_index1);
+ second_module
+     .addFunction("second_export", sig_index_ll)
+     .addBody([
+         kExprGetLocal, 0,
+         kExprI32ConvertI64,
+         kExprCallFunction, 0,
+         kExprI64SConvertI32,
+         kExprReturn
+     ])
+     .exportFunc();
+
+ var first_module = new WasmModuleBuilder();
+ var sig_index = first_module.addType(kSig_i_v);
+ var sig_index_ll = first_module.addType(kSig_l_l);
+ first_module
+     .addImportWithModule("import_module_1", "import_name_1", sig_index_ll);
+ first_module
+     .addFunction("first_export", sig_index)
+     .addBody([
+         kExprI64Const, 2,
+         kExprCallFunction, 2,
+         kExprI32ConvertI64,
+         kExprReturn
+     ])
+     .exportFunc();
+ first_module
+     .addFunction("first_func", sig_index_ll)
+     .addBody([
+         kExprI64Const, 1,
+         kExprGetLocal, 0,
+         kExprI64Add,
+         kExprCallFunction, 0,
+         kExprReturn
+     ]);
+
+ var f = second_module
+     .instantiate({import_module_2: {import_name_2: imported}})
+     .exports.second_export;
+ var the_export = first_module
+     .instantiate({import_module_1: {import_name_1: f}})
+     .exports.first_export;
+   assertEquals(the_export(), 3);
+})();
+
 // function calls stack: first_export -> first_func -> first_import ->
 // second_export -> second_import
 // In this case, second_export has less params than first_import,
 // So that wrappers will not be removed
 (function TestWasmWrapperNoElisionLessParams() {
     var imported = function (a) {
         return a;
     };
 
     var second_module = new WasmModuleBuilder();
@@ skipping 153 matching lines @@
         .exports.second_export;
     var the_export = first_module
         .instantiate({import_module_1: {import_name_1: f}})
         .exports.first_export;
     assertEquals(the_export(2.8, 9.1), 11);
     assertEquals(the_export(-1.7, -2.5), -3);
     assertEquals(the_export(0.0, 0.0), 0);
     assertEquals(the_export(2, -2), 0);
     assertEquals(%CheckWasmWrapperElision(the_export, expect_no_elison), true);
 })();