Cache compile-time constants on the script object, sometimes.

runtime/vm/parser.cc

Index: runtime/vm/parser.cc
diff --git a/runtime/vm/parser.cc b/runtime/vm/parser.cc
index b08d7d846fb2586692b5643dc75eeb374b68afce..80493f29a304f8b34530a57165bf39cecde6d6eb 100644
--- a/runtime/vm/parser.cc
+++ b/runtime/vm/parser.cc
@@ -12134,21 +12134,39 @@ bool Parser::IsInstantiatorRequired() const {
 }
 
 
-void Parser::InsertCachedConstantValue(const String& url,
+void Parser::InsertCachedConstantValue(const Script& script,
                                        TokenPosition token_pos,
                                        const Instance& value) {
   ASSERT(Thread::Current()->IsMutatorThread());
-  Isolate* isolate = Isolate::Current();
-  ConstantPosKey key(url, token_pos);
-  if (isolate->object_store()->compile_time_constants() == Array::null()) {
-    const intptr_t kInitialConstMapSize = 16;
-    isolate->object_store()->set_compile_time_constants(
-        Array::Handle(HashTables::New<ConstantsMap>(kInitialConstMapSize,
-                                                    Heap::kNew)));
+  const intptr_t kInitialConstMapSize = 16;
+  if (script.InVMHeap()) {
+    // For scripts in the vm heap, their constants are in a shared
+    // per-isolate map.
+    Isolate* isolate = Isolate::Current();
+    const String& url = String::Handle(script.url());
+    UrlAndPosKey key(url, token_pos);
+    if (isolate->object_store()->vm_compile_time_constants() == Array::null()) {
+      isolate->object_store()->set_vm_compile_time_constants(
+          Array::Handle(HashTables::New<VMConstantsMap>(
+              kInitialConstMapSize, Heap::kNew)));
+    }
+    VMConstantsMap constants(
+        isolate->object_store()->vm_compile_time_constants());
+    constants.InsertNewOrGetValue(key, value);
+    isolate->object_store()->set_vm_compile_time_constants(constants.Release());
+  } else {
+    // For scripts which are not in the vm heap, their constants are
+    // stored in the script itself.
+    if (script.compile_time_constants() == Array::null()) {
+      const Array& array =
+          Array::Handle(HashTables::New<ConstantsMap>(kInitialConstMapSize,
+                                                      Heap::kNew));
+      script.set_compile_time_constants(array);
+    }
+    ConstantsMap constants(script.compile_time_constants());
+    constants.InsertNewOrGetValue(token_pos, value);
+    script.set_compile_time_constants(constants.Release());
   }
-  ConstantsMap constants(isolate->object_store()->compile_time_constants());
-  constants.InsertNewOrGetValue(key, value);
-  isolate->object_store()->set_compile_time_constants(constants.Release());
 }
 
 
@@ -12159,28 +12177,40 @@ void Parser::CacheConstantValue(TokenPosition token_pos,
     // evaluated only once.
     return;
   }
-  const String& url = String::Handle(Z, script_.url());
-  InsertCachedConstantValue(url, token_pos, value);
-  if (FLAG_compiler_stats) {
-    ConstantsMap constants(isolate()->object_store()->compile_time_constants());
-    thread_->compiler_stats()->num_cached_consts = constants.NumOccupied();
-    constants.Release();
-  }
+  InsertCachedConstantValue(script_, token_pos, value);
 }
 
 
 bool Parser::GetCachedConstant(TokenPosition token_pos, Instance* value) {
-  if (isolate()->object_store()->compile_time_constants() == Array::null()) {
-    return false;
-  }
-  ConstantPosKey key(String::Handle(Z, script_.url()), token_pos);
-  ConstantsMap constants(isolate()->object_store()->compile_time_constants());
   bool is_present = false;
-  *value ^= constants.GetOrNull(key, &is_present);
-  // Mutator compiler thread may add constants while background compiler
-  // is running , and thus change the value of 'compile_time_constants';
-  // do not assert that 'compile_time_constants' has not changed.
-  constants.Release();
+  if (script_.InVMHeap()) {
+    // For scripts in the vm heap, their constants are in a shared
+    // per-isolate map.
+    if (isolate()->object_store()->vm_compile_time_constants() ==
+        Array::null()) {
+      return false;
+    }
+    UrlAndPosKey key(String::Handle(Z, script_.url()), token_pos);
+    VMConstantsMap constants(
+        isolate()->object_store()->vm_compile_time_constants());
+    *value ^= constants.GetOrNull(key, &is_present);
+    // Mutator compiler thread may add constants while background compiler
+    // is running, and thus change the value of 'vm_compile_time_constants';
+    // do not assert that 'vm_compile_time_constants' has not changed.
+    constants.Release();
+  } else {
+    // For scripts which are not in the vm heap, their constants are
+    // stored in the script itself.
+    if (script_.compile_time_constants() == Array::null()) {
+      return false;
+    }
+    ConstantsMap constants(script_.compile_time_constants());
+    *value ^= constants.GetOrNull(token_pos, &is_present);
+    // Mutator compiler thread may add constants while background compiler
+    // is running, and thus change the value of 'compile_time_constants';
+    // do not assert that 'compile_time_constants' has not changed.
+    constants.Release();
+  }
   if (FLAG_compiler_stats && is_present) {
     thread_->compiler_stats()->num_const_cache_hits++;
   }
@@ -14627,7 +14657,7 @@ ParsedFunction* Parser::ParseStaticFieldInitializer(const Field& field) {
 }
 
 
-void Parser::InsertCachedConstantValue(const String& url,
+void Parser::InsertCachedConstantValue(const Script& script,
                                        TokenPosition token_pos,
                                        const Instance& value) {
   UNREACHABLE();