Source positions for constructors and lots of async machinery

runtime/vm/token.h

Index: runtime/vm/token.h
diff --git a/runtime/vm/token.h b/runtime/vm/token.h
index a1018f83c5692a73b168c65104ec6012dd106455..0cd852a7120e91bf545ac54a18f6607b14008e3f 100644
--- a/runtime/vm/token.h
+++ b/runtime/vm/token.h
@@ -6,6 +6,7 @@
 #define VM_TOKEN_H_
 
 #include "platform/assert.h"
+#include "vm/allocation.h"
 
 namespace dart {
 
@@ -216,6 +217,8 @@ class Token {
   static const Kind kLastKeyword = kWITH;
   static const int kNumKeywords = kLastKeyword - kFirstKeyword + 1;
 
+  static const intptr_t kNoSourcePos = -1;
+
   static bool IsAssignmentOperator(Kind tok) {
     return kASSIGN <= tok && tok <= kASSIGN_COND;
   }
@@ -329,6 +332,48 @@ class Token {
 };
 
 
+// These token positions are used to classify instructions that can't be
+// directly tied to an actual source position.
+#define CLASSIFYING_TOKEN_POSITIONS(V)                                         \
+    V(Private, -2)                                                             \
+    V(Box, -3)                                                                 \
+    V(ParallelMove, -4)                                                        \
+    V(TempMove, -5)                                                            \
+    V(Constant, -6)                                                            \
+    V(PushArgument, -7)                                                        \
+    V(ControlFlow, -8)                                                         \
+    V(Context, -9)                                                             \
+    V(MethodExtractor, -10)
+
+// COMPILE_ASSERT that all CLASSIFYING_TOKEN_POSITIONS are less than
+// Token::kNoSourcePos.
+#define SANITY_CHECK_VALUES(name, value)                                       \
+  COMPILE_ASSERT(value < Token::kNoSourcePos);
+  CLASSIFYING_TOKEN_POSITIONS(SANITY_CHECK_VALUES);
+#undef SANITY_CHECK_VALUES
+
+class ClassifyingTokenPositions : public AllStatic {
+ public:
+#define DEFINE_VALUES(name, value)                                             \
+  static const intptr_t k##name = value;
+  CLASSIFYING_TOKEN_POSITIONS(DEFINE_VALUES);
+#undef DEFINE_VALUES
+
+  static const char* ToCString(intptr_t token_pos) {
+    ASSERT(token_pos < 0);
+    switch (token_pos) {
+      case Token::kNoSourcePos: return "NoSource";
+#define DEFINE_CASE(name, value)                                               \
+      case value: return #name;
+      CLASSIFYING_TOKEN_POSITIONS(DEFINE_CASE);
+#undef DEFINE_CASE
+      default:
+        UNIMPLEMENTED();
+        return NULL;
+    }
+  }
+};
+
 }  // namespace dart
 
 #endif  // VM_TOKEN_H_