Implement proper module linking.

src/scopes.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 11 matching lines @@
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include "v8.h"
 
 #include "scopes.h"
 
+#include "accessors.h"
 #include "bootstrapper.h"
 #include "compiler.h"
 #include "messages.h"
 #include "scopeinfo.h"
 
 #include "allocation-inl.h"
 
 namespace v8 {
 namespace internal {
 
@@ skipping 177 matching lines @@
       Scope* with_scope = new(zone) Scope(current_scope,
                                           WITH_SCOPE,
                                           Handle<ScopeInfo>::null(),
                                           zone);
       current_scope = with_scope;
       // All the inner scopes are inside a with.
       contains_with = true;
       for (Scope* s = innermost_scope; s != NULL; s = s->outer_scope()) {
         s->scope_inside_with_ = true;
       }
+    } else if (context->IsModuleContext()) {
+      ScopeInfo* scope_info = ScopeInfo::cast(context->module()->scope_info());
+      current_scope = new(zone) Scope(current_scope,
+                                      MODULE_SCOPE,
+                                      Handle<ScopeInfo>(scope_info),
+                                      zone);
     } else if (context->IsFunctionContext()) {
       ScopeInfo* scope_info = context->closure()->shared()->scope_info();
       current_scope = new(zone) Scope(current_scope,
                                       FUNCTION_SCOPE,
                                       Handle<ScopeInfo>(scope_info),
                                       zone);
     } else if (context->IsBlockContext()) {
       ScopeInfo* scope_info = ScopeInfo::cast(context->extension());
       current_scope = new(zone) Scope(current_scope,
                                       BLOCK_SCOPE,
@@ skipping 388 matching lines @@
         outer_scope_->calls_non_strict_eval();
   }
   PropagateScopeInfo(outer_scope_calls_non_strict_eval);
 
   // 2) Resolve variables.
   if (!ResolveVariablesRecursively(info, factory)) return false;
 
   // 3) Allocate variables.
   AllocateVariablesRecursively();
 
+  // 4) Allocate and link module instance objects.
+  if (FLAG_harmony_modules) {
+    if (is_global_scope() || is_module_scope()) {

[Michael Starzinger, 2012/07/06 10:53:22]

Can we merge that into one condition?

[rossberg, 2012/07/06 15:39:28]

Done.

+      AllocateModules(info);
+      LinkModules(info);
+    }
+  }
+
   return true;
 }
 
 
 bool Scope::HasTrivialContext() const {
   // A function scope has a trivial context if it always is the global
   // context. We iteratively scan out the context chain to see if
   // there is anything that makes this scope non-trivial; otherwise we
   // return true.
   for (const Scope* scope = this; scope != NULL; scope = scope->outer_scope_) {
@@ skipping 457 matching lines @@
 bool Scope::MustAllocate(Variable* var) {
   // Give var a read/write use if there is a chance it might be accessed
   // via an eval() call.  This is only possible if the variable has a
   // visible name.
   if ((var->is_this() || var->name()->length() > 0) &&
       (var->has_forced_context_allocation() ||
        scope_calls_eval_ ||
        inner_scope_calls_eval_ ||
        scope_contains_with_ ||
        is_catch_scope() ||
-       is_block_scope())) {
+       is_block_scope() ||
+       is_module_scope())) {
     var->set_is_used(true);
   }
   // Global variables do not need to be allocated.
   return !var->is_global() && var->is_used();
 }
 
 
 bool Scope::MustAllocateInContext(Variable* var) {
   // If var is accessed from an inner scope, or if there is a possibility
   // that it might be accessed from the current or an inner scope (through
@@ skipping 167 matching lines @@
       (function_ != NULL && function_->proxy()->var()->IsStackLocal() ? 1 : 0);
 }
 
 
 int Scope::ContextLocalCount() const {
   if (num_heap_slots() == 0) return 0;
   return num_heap_slots() - Context::MIN_CONTEXT_SLOTS -
       (function_ != NULL && function_->proxy()->var()->IsContextSlot() ? 1 : 0);
 }
 
+
+void Scope::AllocateModules(CompilationInfo* info) {
+  ASSERT(is_global_scope() || is_module_scope());
+
+  if (is_module_scope()) {
+    ASSERT(interface_->IsFrozen());
+    ASSERT(scope_info_.is_null());
+
+    // TODO(rossberg): This has to be the initial compilation of this code.
+    // We currently do not allow recompiling any module definitions.
+    Handle<ScopeInfo> scope_info = GetScopeInfo();
+    Factory* factory = info->isolate()->factory();
+    Handle<Context> context = factory->NewModuleContext(scope_info);
+    Handle<JSModule> instance = factory->NewJSModule(context, scope_info);
+    context->set_module(*instance);
+
+    bool ok;
+    interface_->MakeSingleton(instance, &ok);
+    ASSERT(ok);
+  }
+
+  // Allocate nested modules.
+  for (int i = 0; i < inner_scopes_.length(); i++) {
+    Scope* inner_scope = inner_scopes_.at(i);
+    if (inner_scope->is_module_scope()) {
+      inner_scope->AllocateModules(info);
+    }
+  }
+}
+
+
+void Scope::LinkModules(CompilationInfo* info) {
+  ASSERT(is_global_scope() || is_module_scope());
+
+  if (is_module_scope()) {
+    Handle<JSModule> instance = interface_->Instance();
+
+    // Populate the module instance object.
+    const PropertyAttributes ro_attr =
+        static_cast<PropertyAttributes>(READ_ONLY | DONT_DELETE | DONT_ENUM);
+    const PropertyAttributes rw_attr =
+        static_cast<PropertyAttributes>(DONT_DELETE | DONT_ENUM);
+    for (Interface::Iterator it = interface_->iterator();
+         !it.done(); it.Advance()) {
+      if (it.interface()->IsModule()) {
+        Handle<Object> value = it.interface()->Instance();
+        ASSERT(!value.is_null());
+        JSReceiver::SetProperty(
+            instance, it.name(), value, ro_attr, kStrictMode);
+      } else {
+        Variable* var = LocalLookup(it.name());
+        ASSERT(var != NULL && var->IsContextSlot());
+        PropertyAttributes attr = var->is_const_mode() ? ro_attr : rw_attr;
+        Handle<AccessorInfo> info =
+            Accessors::MakeModuleExport(it.name(), var->index(), attr);
+        Handle<Object> result = SetAccessor(instance, info);
+        ASSERT(!(result.is_null() || result->IsUndefined()));
+      }
+    }
+    USE(instance->PreventExtensions());

[Michael Starzinger, 2012/07/06 10:53:22]

This might request a GC, so you should use JSObject::PreventExtensions(instance)
here.

[rossberg, 2012/07/06 15:39:28]

Done.

+  }
+
+  // Link nested modules.
+  for (int i = 0; i < inner_scopes_.length(); i++) {
+    Scope* inner_scope = inner_scopes_.at(i);
+    if (inner_scope->is_module_scope()) {
+      inner_scope->LinkModules(info);
+    }
+  }
+}
+
+
 } }  // namespace v8::internal