Debugging in kernel shaping up.

runtime/vm/object.cc

Index: runtime/vm/object.cc
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index 217063ac6a905af39516379e4251c4f2bf158b30..dae9d71f0bb79f886c8bae612a290074735d9eb3 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -8866,15 +8866,38 @@ RawGrowableObjectArray* Script::GenerateLineNumberArray() const {
     }
     intptr_t line_count = line_starts_array.Length();
     ASSERT(line_count > 0);
+    const Array& debug_positions_array = Array::Handle(debug_positions());
+    intptr_t token_count = debug_positions_array.Length();
+    int token_index = 0;
+
+    for (int line_index = 0; line_index < line_count; ++line_index) {
+      value ^= line_starts_array.At(line_index);
+      intptr_t start = value.Value();
+      // Output the rest of the tokens if we have no next line.
+      intptr_t end = kMaxInt32;

[Kevin Millikin (Google), 2017/01/31 10:40:37]

Maybe we actually want TokenPosition::kMaxSourcePos here?  At least, if we
change TokenPosition we'll still have the right constant.

+      if (line_index + 1 < line_count) {
+        value ^= line_starts_array.At(line_index + 1);
+        end = value.Value();
+      }
+      bool first = true;
+      while (token_index < token_count) {
+        value ^= debug_positions_array.At(token_index);
+        intptr_t debug_position = value.Value();
+        if (debug_position >= end) break;
+
+        if (first) {
+          info.Add(line_separator);          // New line.
+          value = Smi::New(line_index + 1);  // Line number.
+          info.Add(value);
+          first = false;
+        }
 
-    for (int i = 0; i < line_count; i++) {
-      info.Add(line_separator);  // New line.
-      value = Smi::New(i + 1);
-      info.Add(value);  // Line number.
-      value ^= line_starts_array.At(i);
-      info.Add(value);  // Token position.
-      value = Smi::New(1);
-      info.Add(value);  // Column.
+        value ^= debug_positions_array.At(token_index);
+        info.Add(value);                               // Token position.
+        value = Smi::New(debug_position - start + 1);  // Column.
+        info.Add(value);
+        ++token_index;
+      }
     }
     return info.raw();
   }
@@ -8995,6 +9018,14 @@ void Script::set_line_starts(const Array& value) const {
 }
 
 
+void Script::set_debug_positions(const Array& value) const {
+  StorePointer(&raw_ptr()->debug_positions_, value.raw());
+}
+
+void Script::set_yield_positions(const Array& value) const {
+  StorePointer(&raw_ptr()->yield_positions_, value.raw());
+}
+
 void Script::set_kind(RawScript::Kind value) const {
   StoreNonPointer(&raw_ptr()->kind_, value);
 }
@@ -9085,6 +9116,8 @@ void Script::GetTokenLocation(TokenPosition token_pos,
       *column = offset - smi.Value() + 1;
     }
     if (token_len != NULL) {
+      // We don't explicitly save this data.
+      // TODO(jensj): Load the source and attempt to find it from there.
       *token_len = 1;
     }
     return;