Get rid of PropagateScopeInfo, update asm_function in set_asm_module instead.

The last user was propagating asm_module_ to inner function scopes as asm_function_. asm_function_ is already set upon scope creation when the outer scope IsAsmModule(). With default parameter it's possible that inner scopes are created before set_asm_module() is called. To keep current behavior we'll eagerly mark inner scopes as asm_function_ upon set_asm_module().

There's only one special case that used to be marked asm_function_ which is now no longer marked as such: asm functions in block scopes that are 'Finalized'. PropagateScopeInfo used to mark them as asm_function_ as well, whereas the new version would not mark them upon construction of the inner scope.

I presume both above cornercases aren't actually intended valid asm.js use-cases anyway. The second we can now easily identify in the verifier and mark as invalid asm, since we'll have an asm module with non-asm-function inner functions. If we want to disallow the first, we can also not mark them as asm_functions_ (by removing the loop I added in set_asm_module), which will reveal this structure to the validator.

BUG=v8:5209

Review-Url: https://codereview.chromium.org/2270743003
Cr-Commit-Position: refs/heads/master@{#39039}

src/ast/scopes.cc

@@ -251,6 +251,16 @@ bool Scope::HasSimpleParameters() {
   return !scope->is_function_scope() || scope->has_simple_parameters();
 }
 
+void DeclarationScope::set_asm_module() {
+  asm_module_ = true;
+  // Mark any existing inner function scopes as asm function scopes.
+  for (Scope* inner = inner_scope_; inner != nullptr; inner = inner->sibling_) {
+    if (inner->is_function_scope()) {
+      inner->AsDeclarationScope()->set_asm_function();
+    }
+  }
+}
+
 bool Scope::IsAsmModule() const {
   return is_function_scope() && AsDeclarationScope()->asm_module();
 }
@@ -329,7 +339,6 @@ Scope* Scope::DeserializeScopeChain(Isolate* isolate, Zone* zone,
 
   if (innermost_scope == nullptr) return script_scope;
   script_scope->AddInnerScope(current_scope);
-  script_scope->PropagateScopeInfo();
   return innermost_scope;
 }
 
@@ -878,7 +887,6 @@ Declaration* Scope::CheckLexDeclarationsConflictingWith(
 }
 
 void DeclarationScope::AllocateVariables(ParseInfo* info, AnalyzeMode mode) {
-  PropagateScopeInfo();
   ResolveVariablesRecursively(info);
   AllocateVariablesRecursively();
   AllocateScopeInfosRecursively(info->isolate(), mode);
@@ -981,9 +989,6 @@ Handle<StringSet> DeclarationScope::CollectNonLocals(
 
 void DeclarationScope::AnalyzePartially(DeclarationScope* migrate_to,
                                         AstNodeFactory* ast_node_factory) {
-  // Gather info from inner scopes.
-  PropagateScopeInfo();
-
   // Try to resolve unresolved variables for this Scope and migrate those which
   // cannot be resolved inside. It doesn't make sense to try to resolve them in
   // the outer Scopes here, because they are incomplete.
@@ -1403,16 +1408,6 @@ VariableProxy* Scope::FetchFreeVariables(DeclarationScope* max_outer_scope,
   return stack;
 }
 
-void Scope::PropagateScopeInfo() {
-  for (Scope* inner = inner_scope_; inner != nullptr; inner = inner->sibling_) {
-    inner->PropagateScopeInfo();
-    if (IsAsmModule() && inner->is_function_scope()) {
-      inner->AsDeclarationScope()->set_asm_function();
-    }
-  }
-}
-
-
 bool Scope::MustAllocate(Variable* var) {
   DCHECK(var->location() != VariableLocation::MODULE);
   // Give var a read/write use if there is a chance it might be accessed

src/ast/scopes.h

@@ -531,9 +531,6 @@ class Scope: public ZoneObject {
                                     ParseInfo* info = nullptr,
                                     VariableProxy* stack = nullptr);
 
-  // Scope analysis.
-  void PropagateScopeInfo();
-
   // Predicates.
   bool MustAllocate(Variable* var);
   bool MustAllocateInContext(Variable* var);
@@ -624,7 +621,7 @@ class DeclarationScope : public Scope {
   }
 
   bool asm_module() const { return asm_module_; }
-  void set_asm_module() { asm_module_ = true; }
+  void set_asm_module();
   bool asm_function() const { return asm_function_; }
   void set_asm_function() { asm_module_ = true; }