Parser & internalization fix: ensure no heap allocs during GetString(Handle<String>).

src/ast-value-factory.cc

Index: src/ast-value-factory.cc
diff --git a/src/ast-value-factory.cc b/src/ast-value-factory.cc
index 895ce39f652845fa83674d61ec98b0c9b8f1b5e1..2a98d07105b1fd4d02d5bb5ed01eec18f6e0db75 100644
--- a/src/ast-value-factory.cc
+++ b/src/ast-value-factory.cc
@@ -229,13 +229,28 @@ const AstRawString* AstValueFactory::GetTwoByteString(
 
 
 const AstRawString* AstValueFactory::GetString(Handle<String> literal) {
+  // For the FlatContent to stay valid, we shouldn't do any heap
+  // allocation. Make sure we won't try to internalize the string in GetString.
+  AstRawString* result = NULL;
+  Isolate* saved_isolate = isolate_;
+  isolate_ = NULL;
   DisallowHeapAllocation no_gc;
   String::FlatContent content = literal->GetFlatContent();
   if (content.IsOneByte()) {
-    return GetOneByteString(content.ToOneByteVector());

[rossberg, 2014/11/05 12:39:51]

I'm confused, what's the reason to inline these functions? Unless I'm missing
something, the code is identical.

[marja, 2014/11/05 12:41:41]

constness.

Another option would be to make these API functions return AstRawString* instead
of const AstRawString* but that's also somewhat meh.

(The users are anyway supposed to e.g., internalize the AstRawStrings they get,
so returning const AstRawString* is more correct..)

[rossberg, 2014/11/05 12:46:21]

Why not make the functions non-const but private, and have the public ones be
thin const wrappers?

+    Vector<const uint8_t> literal = content.ToOneByteVector();
+    uint32_t hash = StringHasher::HashSequentialString<uint8_t>(
+        literal.start(), literal.length(), hash_seed_);
+    result = GetString(hash, true, literal);
+  } else {
+    DCHECK(content.IsTwoByte());
+    Vector<const uint16_t> literal = content.ToUC16Vector();
+    uint32_t hash = StringHasher::HashSequentialString<uint16_t>(
+        literal.start(), literal.length(), hash_seed_);
+    result = GetString(hash, false, Vector<const byte>::cast(literal));
   }
-  DCHECK(content.IsTwoByte());
-  return GetTwoByteString(content.ToUC16Vector());
+  isolate_ = saved_isolate;
+  result->string_ = literal;
+  return result;
 }
 
 
@@ -348,8 +363,8 @@ const AstValue* AstValueFactory::NewTheHole() {
 
 #undef GENERATE_VALUE_GETTER
 
-const AstRawString* AstValueFactory::GetString(
-    uint32_t hash, bool is_one_byte, Vector<const byte> literal_bytes) {
+AstRawString* AstValueFactory::GetString(uint32_t hash, bool is_one_byte,
+                                         Vector<const byte> literal_bytes) {
   // literal_bytes here points to whatever the user passed, and this is OK
   // because we use vector_compare (which checks the contents) to compare
   // against the AstRawStrings which are in the string_table_. We should not