[wasm] Get rid of extra wrappers when import another wasm export

test/mjsunit/wasm/test-import-export-wrapper.js

Index: test/mjsunit/wasm/test-import-export-wrapper.js
diff --git a/test/mjsunit/wasm/test-import-export-wrapper.js b/test/mjsunit/wasm/test-import-export-wrapper.js
new file mode 100644
index 0000000000000000000000000000000000000000..698a46802f920ccea291e90858a0efaf8304c142
--- /dev/null
+++ b/test/mjsunit/wasm/test-import-export-wrapper.js
@@ -0,0 +1,154 @@
+// 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");
+
+(function TestImportExportNoWrapper() {
+    var second_module = new WasmModuleBuilder();
+    var sig_index = second_module.addType(kSig_v_i);
+    second_module.addImportWithModule("js", "thePrint", sig_index);

[Mircea Trofin, 2016/08/03 22:52:16]

can you change the names, instead of "thePrint" and "blah", "nothing", etc, to
something more suggestive (e.g. export_1, export_2, etc)

also, mind adding in comments what the functions do? makes it easy to read.

+    second_module.addFunction("second_export", sig_index)
+                .addBody([
+                    kExprGetLocal, 0,
+                    kExprCallImport, kArity1, 0
+                ])
+                .exportFunc();
+
+    var first_module = new WasmModuleBuilder();
+    var sig_index = first_module.addType(kSig_v_i);
+    first_module.addImportWithModule("blah", "nothing", sig_index);
+    first_module.addFunction("export_fct", sig_index)
+                .addBody([
+                    kExprGetLocal, 0,
+                    kExprCallFunction, kArity1, 1
+                ])
+                .exportFunc();
+    first_module.addFunction("increment", sig_index)
+                .addBody([
+                    kExprI32Const, 1,
+                    kExprGetLocal, 0,
+                    kExprI32Add,
+                    kExprCallImport, kArity1, 0
+                ]);
+
+    var f = second_module.instantiate({js:{thePrint:print}}).exports.second_export;

[Mircea Trofin, 2016/08/03 22:52:16]

80 char limit - git cl format, unfortunately, doesn't help for js files.

+    var the_export = first_module.instantiate({blah:{nothing:f}}).exports.export_fct;
+
+    the_export(2);

[Mircea Trofin, 2016/08/03 22:52:16]

want to check the result?

+    %CheckImportExportFunction(the_export, 0);

[Mircea Trofin, 2016/08/03 22:52:16]

maybe add somewhere a var expect_no_elision = 1 and var expect_elision = 0

+
+})();
+
+(function TestImportExportWrapperLessParams() {
+    var second_module = new WasmModuleBuilder();
+    var sig_index_1 = second_module.addType(kSig_v_i);
+    second_module.addImportWithModule("js", "thePrint", sig_index_1);
+    second_module.addFunction("second_export", sig_index_1)
+        .addBody([
+            kExprGetLocal, 0,
+            kExprCallImport, kArity1, 0
+        ])
+        .exportFunc();
+
+    var first_module = new WasmModuleBuilder();
+    var sig_index_2 = first_module.addType(kSig_v_ii);
+    first_module.addImportWithModule("blah", "nothing", sig_index_2);
+    first_module.addFunction("export_fct", sig_index_2)
+        .addBody([
+            kExprGetLocal, 0,
+            kExprGetLocal, 1,
+            kExprCallFunction, kArity2, 1
+        ])
+        .exportFunc();
+    first_module.addFunction("increment", sig_index_2)
+        .addBody([
+            kExprGetLocal, 0,
+            kExprGetLocal, 1,
+            kExprCallImport, kArity2, 0
+        ]);
+
+    var f = second_module.instantiate({js:{thePrint:print}}).exports.second_export;
+    var the_export = first_module.instantiate({blah:{nothing:f}}).exports.export_fct;
+
+    the_export(4, 3);

[Mircea Trofin, 2016/08/03 22:52:16]

check result? (same for the remainder)

should the call fail here?

+    %CheckImportExportFunction(the_export, 1);
+
+})();
+
+(function TestImportExportWrapperMoreParams() {
+    var second_module = new WasmModuleBuilder();
+    var sig_index_3 = second_module.addType(kSig_v_iii);
+    second_module.addImportWithModule("js", "thePrint", sig_index_3);
+    second_module.addFunction("second_export", sig_index_3)
+        .addBody([
+            kExprGetLocal, 0,
+            kExprGetLocal, 1,
+            kExprGetLocal, 2,
+            kExprCallImport, kArity3, 0
+        ])
+        .exportFunc();
+
+    var first_module = new WasmModuleBuilder();
+    var sig_index_2 = first_module.addType(kSig_v_ii);
+    first_module.addImportWithModule("blah", "nothing", sig_index_2);
+    first_module.addFunction("export_fct", sig_index_2)
+        .addBody([
+            kExprGetLocal, 0,
+            kExprGetLocal, 1,
+            kExprCallFunction, kArity2, 1
+        ])
+        .exportFunc();
+    first_module.addFunction("increment", sig_index_2)
+        .addBody([
+            kExprGetLocal, 0,
+            kExprGetLocal, 1,
+            kExprCallImport, kArity2, 0
+        ]);
+
+    var f = second_module.instantiate({js:{thePrint:print}}).exports.second_export;
+    var the_export = first_module.instantiate({blah:{nothing:f}}).exports.export_fct;
+
+    the_export(5, 4);
+    %CheckImportExportFunction(the_export, 1);
+
+})();
+
+(function TestImportExportWrapperTypeMismatch() {
+    var second_module = new WasmModuleBuilder();
+    var sig_index_2 = second_module.addType(kSig_v_dd);
+    second_module.addImportWithModule("js", "thePrint", sig_index_2);
+    second_module.addFunction("second_export", sig_index_2)
+        .addBody([
+            kExprGetLocal, 0,
+            kExprGetLocal, 1,
+            kExprCallImport, kArity2, 0
+        ])
+        .exportFunc();
+
+    var first_module = new WasmModuleBuilder();
+    var sig_index_2 = first_module.addType(kSig_v_ii);
+    first_module.addImportWithModule("blah", "nothing", sig_index_2);
+    first_module.addFunction("export_fct", sig_index_2)
+        .addBody([
+            kExprGetLocal, 0,
+            kExprGetLocal, 1,
+            kExprCallFunction, kArity2, 1
+        ])
+        .exportFunc();
+    first_module.addFunction("increment", sig_index_2)
+        .addBody([
+            kExprGetLocal, 0,
+            kExprGetLocal, 1,
+            kExprCallImport, kArity2, 0
+        ]);
+
+    var f = second_module.instantiate({js:{thePrint:print}}).exports.second_export;
+    var the_export = first_module.instantiate({blah:{nothing:f}}).exports.export_fct;
+
+    the_export(6, 8);
+    %CheckImportExportFunction(the_export, 1);
+})();