[dart2wasm] Make imported globals/functions have nicer name

When a function/global is used cross-module then the implementation will
export from defining module and import from using module.

=> Make the imported function/global have the same local name as the
   defining one.

=> This only influences the names in the name section which are stripped
   for deployed modules.

Change-Id: I770233f5e7c5d08050e8189402e7294b88212651
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/458840
Reviewed-by: Ömer Ağacan <[email protected]>
Commit-Queue: Ömer Ağacan <[email protected]>

Author: mkustermann

pkg/dart2wasm/lib/translator.dart

@@ -2807,8 +2807,10 @@ class WasmFunctionImporter extends _WasmImporter<w.BaseFunction> {
   @override
   w.BaseFunction _import(w.ModuleBuilder importingModule,
       w.BaseFunction definition, String moduleName, String importName) {
-    return importingModule.functions
+    final function = importingModule.functions
         .import(moduleName, importName, definition.type, definition.name);
+    function.functionName = definition.functionName;
+    return function;
   }
 }
 
@@ -2818,8 +2820,10 @@ class WasmGlobalImporter extends _WasmImporter<w.Global> {
   @override
   w.Global _import(w.ModuleBuilder importingModule, w.Global definition,
       String moduleName, String importName) {
-    return importingModule.globals
-        .import(moduleName, importName, definition.type);
+    final global =
+        importingModule.globals.import(moduleName, importName, definition.type);
+    global.globalName = definition.globalName;
+    return global;
   }
 }
 

pkg/dart2wasm/test/ir_tests/deferred.constant.wat

@@ -6,12 +6,12 @@
     (field $field0 i32)
     (field $field1 (mut i32))
     (field $fun (ref $#Closure-0-1)))))
-  (type $type246 <...>)
-  (type $type249 <...>)
-  (type $type252 <...>)
-  (table $static1-0 (export "static1-0") 1 (ref null $type252))
-  (table $static2-0 (export "static2-0") 1 (ref null $type246))
-  (table $static3-0 (export "static3-0") 1 (ref null $type249))
+  (type $type245 <...>)
+  (type $type248 <...>)
+  (type $type251 <...>)
+  (table $static1-0 (export "static1-0") 1 (ref null $type251))
+  (table $static2-0 (export "static2-0") 1 (ref null $type245))
+  (table $static3-0 (export "static3-0") 1 (ref null $type248))
   (func $print (param $var0 (ref null $#Top)) (result (ref null $#Top)) <...>)
   (func $"modMainUseH0 <noInline>"
     i64.const 0

pkg/dart2wasm/test/ir_tests/deferred.constant_module1.wat

@@ -22,9 +22,9 @@
   (type $BoxedInt <...>)
   (func $print (import "module0" "func5") (param (ref null $#Top)) (result (ref null $#Top)))
   (func $JSStringImpl._interpolate (import "module0" "func6") (param (ref $Array<Object?>)) (result (ref $JSStringImpl)))
-  (global $module0.global0 (import "module0" "global0") (ref $JSStringImpl))
-  (global $module0.global5 (import "module0" "global5") (ref $_InterfaceType))
-  (global $module0.global7 (import "module0" "global7") (ref $_FunctionType))
+  (global $"C21 \")\"" (import "module0" "global0") (ref $JSStringImpl))
+  (global $"C28 _InterfaceType" (import "module0" "global5") (ref $_InterfaceType))
+  (global $"C455 _FunctionType" (import "module0" "global7") (ref $_FunctionType))
   (global $S.globalH1Bar< (import "S" "globalH1Bar<") (ref extern))
   (global $global7 (ref $#Vtable-1-1) <...>)
   (global $global4 (ref $#DummyStruct) <...>)
@@ -73,7 +73,7 @@
     local.get $var0
     global.get $"C464 \">(\""
     local.get $var1
-    global.get $module0.global0
+    global.get $"C21 \")\""
     array.new_fixed $Array<Object?> 5
     call $JSStringImpl._interpolate
     call $print
@@ -119,13 +119,13 @@
         global.set $"C460 globalH1Foo tear-off"
         local.get $var0
       end $label1
-      global.get $module0.global5
+      global.get $"C28 _InterfaceType"
       struct.new $#InstantiationContext-1-1
       ref.func $"dynamic call entry"
       ref.func $"#dummy function (ref struct) -> (ref null #Top)"
       ref.func $"instantiation constant trampoline"
       struct.new $#Vtable-0-1
-      global.get $module0.global7
+      global.get $"C455 _FunctionType"
       struct.new $#Closure-0-1
       local.tee $var1
       global.set $"C461 InstantiationConstant(globalH1Foo<int>)"

pkg/dart2wasm/test/ir_tests/deferred.constant_module2.wat

@@ -4,7 +4,6 @@
   (type $Array<Object?> <...>)
   (type $JSStringImpl <...>)
   (type $Array<_Type> <...>)
-  (type $BoxedInt <...>)
   (type $_FunctionType <...>)
   (type $#ClosureBase <...>)
   (type $#Vtable-0-1 <...>)
@@ -15,7 +14,7 @@
     (field $fun (ref $#Closure-0-1)))))
   (type $#DummyStruct <...>)
   (func $print (import "module0" "func5") (param (ref null $#Top)) (result (ref null $#Top)))
-  (global $module0.global7 (import "module0" "global7") (ref $_FunctionType))
+  (global $"C455 _FunctionType" (import "module0" "global7") (ref $_FunctionType))
   (global $S.globalH0Foo (import "S" "globalH0Foo") (ref extern))
   (global $global6 (ref $#Vtable-0-1) <...>)
   (global $global3 (ref $#DummyStruct) <...>)
@@ -33,18 +32,10 @@
     call $print
   )
   (func $"globalH0Foo tear-off dynamic call entry" (param $var0 (ref $#ClosureBase)) (param $var1 (ref $Array<_Type>)) (param $var2 (ref $Array<Object?>)) (param $var3 (ref $Array<Object?>)) (result (ref null $#Top))
-    local.get $var2
-    i32.const 0
-    array.get $Array<Object?>
-    ref.cast $BoxedInt
-    drop
     global.get $"C467 \"globalH0Foo\""
     call $print
   )
   (func $"globalH0Foo tear-off trampoline" (param $var0 (ref struct)) (param $var1 (ref null $#Top)) (result (ref null $#Top))
-    local.get $var1
-    ref.cast $BoxedInt
-    drop
     global.get $"C467 \"globalH0Foo\""
     call $print
   )
@@ -60,7 +51,7 @@
       i32.const 0
       global.get $global3
       global.get $global6
-      global.get $module0.global7
+      global.get $"C455 _FunctionType"
       struct.new $#Closure-0-1
       local.tee $var0
       global.set $"C465 globalH0Foo tear-off"

pkg/dart2wasm/test/ir_tests/import_name.dart

@@ -0,0 +1,19 @@
+// Copyright (c) 2025, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// functionFilter=Foo
+// compilerOption=--enable-deferred-loading
+// compilerOption=--no-minify
+
+import 'import_name.h.0.dart' deferred as h0;
+
+void main() async {
+  await h0.loadLibrary();
+  h0.deferredFoo();
+}
+
+@pragma('wasm:never-inline')
+void mainFoo() {
+  print('hello world');
+}

pkg/dart2wasm/test/ir_tests/import_name.h.0.dart

@@ -0,0 +1,10 @@
+// Copyright (c) 2025, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'import_name.dart';
+
+@pragma('wasm:never-inline')
+void deferredFoo() {
+  mainFoo();
+}

pkg/dart2wasm/test/ir_tests/import_name.wat

@@ -0,0 +1,23 @@
+(module $module0
+  (type $#Top (struct
+    (field $field0 i32)))
+  (type $Object (sub $#Top (struct
+    (field $field0 i32)
+    (field $field1 (mut i32)))))
+  (type $JSStringImpl (sub final $Object (struct
+    (field $field0 i32)
+    (field $field1 (mut i32))
+    (field $_ref externref))))
+  (global $"S.hello world" (import "S" "hello world") (ref extern))
+  (global $"C367 \"hello world\"" (ref $JSStringImpl)
+    (i32.const 4)
+    (i32.const 0)
+    (global.get $"S.hello world")
+    (struct.new $JSStringImpl))
+  (func $print (param $var0 (ref $#Top)) <...>)
+  (func $"mainFoo <noInline>" (export "func0") (result (ref null $#Top))
+    global.get $"C367 \"hello world\""
+    call $print
+    ref.null none
+  )
+)

pkg/dart2wasm/test/ir_tests/import_name_module1.wat

@@ -0,0 +1,10 @@
+(module $module1
+  (type $#Top (struct
+    (field $field0 i32)))
+  (func $"mainFoo <noInline>" (import "module0" "func0") (result (ref null $#Top)))
+  (func $"deferredFoo <noInline>" (result (ref null $#Top))
+    call $"mainFoo <noInline>"
+    drop
+    ref.null none
+  )
+)