Correct handling of temporaries as parameters.

They need to be properly recorded in the scope's temps set, otherwise allocation doesn't know about them and can break. (Not observable right now, but necessary for follow-up changes to parameter destructuring.)

Also, print temporary variables in a useful manner.

R=adamk@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1263563002

Cr-Commit-Position: refs/heads/master@{#29998}

diff --git a/src/parser.h b/src/parser.h
index df1b439..733665c 100644 (file)
--- a/src/parser.h
+++ b/src/parser.h
@@ -1317,8 +1317,9 @@ void ParserTraits::DeclareFormalParameter(
   const AstRawString* name = is_simple
                                  ? pattern->AsVariableProxy()->raw_name()
                                  : parser_->ast_value_factory()->empty_string();
+  VariableMode mode = is_simple ? VAR : TEMPORARY;
   Variable* var =
-      parameters->scope->DeclareParameter(name, VAR, is_rest, &is_duplicate);
+      parameters->scope->DeclareParameter(name, mode, is_rest, &is_duplicate);
   parameters->AddParameter(var, is_simple ? nullptr : pattern);
   if (is_duplicate) {
     classifier->RecordDuplicateFormalParameterError(

diff --git a/src/scopes.cc b/src/scopes.cc
index 52e50ea..0240049 100644 (file)
--- a/src/scopes.cc
+++ b/src/scopes.cc
@@ -465,16 +465,14 @@ Variable* Scope::DeclareParameter(const AstRawString* name, VariableMode mode,
                                   bool is_rest, bool* is_duplicate) {
   DCHECK(!already_resolved());
   DCHECK(is_function_scope());
-
   Variable* var;
-  if (!name->IsEmpty()) {
+  if (mode == TEMPORARY) {
+    var = NewTemporary(name);
+  } else {
     var = variables_.Declare(this, name, mode, Variable::NORMAL,
                              kCreatedInitialized);
     // TODO(wingo): Avoid O(n^2) check.
     *is_duplicate = IsDeclaredParameter(name);
-  } else {
-    var = new (zone())
-        Variable(this, name, TEMPORARY, Variable::NORMAL, kCreatedInitialized);
   }
   if (is_rest) {
     DCHECK_NULL(rest_parameter_);
@@ -620,9 +618,10 @@ void Scope::CollectStackAndContextLocals(
       if (var->IsContextSlot()) {
         DCHECK(has_forced_context_allocation());
         context_locals->Add(var, zone());
-      } else {
-        DCHECK(var->IsStackLocal());
+      } else if (var->IsStackLocal()) {
         stack_locals->Add(var, zone());
+      } else {
+        DCHECK(var->IsParameter());
       }
     }
   }
@@ -863,7 +862,10 @@ static void PrintVar(int indent, Variable* var) {
   if (var->is_used() || !var->IsUnallocated()) {
     Indent(indent, Variable::Mode2String(var->mode()));
     PrintF(" ");
-    PrintName(var->raw_name());
+    if (var->raw_name()->IsEmpty())
+      PrintF(".%p", var);
+    else
+      PrintName(var->raw_name());
     PrintF(";  // ");
     PrintLocation(var);
     bool comma = !var->IsUnallocated();
@@ -909,7 +911,11 @@ void Scope::Print(int n) {
     PrintF(" (");
     for (int i = 0; i < params_.length(); i++) {
       if (i > 0) PrintF(", ");
-      PrintName(params_[i]->raw_name());
+      const AstRawString* name = params_[i]->raw_name();
+      if (name->IsEmpty())
+        PrintF(".%p", params_[i]);
+      else
+        PrintName(name);
     }
     PrintF(")");
   }

diff --git a/src/variables.h b/src/variables.h
index deebc5f..dcd2e6a 100644 (file)
--- a/src/variables.h
+++ b/src/variables.h
@@ -44,7 +44,6 @@ class Variable: public ZoneObject {
     return force_context_allocation_;
   }
   void ForceContextAllocation() {
-    DCHECK(mode_ != TEMPORARY);
     force_context_allocation_ = true;
   }
   bool is_used() { return is_used_; }