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 3675bfb32ff3382e8771900b79c80636bf4cdfb1..6c9502daf11f0fa12cacd7221e946d2ea67a444b 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -8845,15 +8845,42 @@ RawGrowableObjectArray* Script::GenerateLineNumberArray() const {
     }
     intptr_t line_count = line_starts_array.Length();
     ASSERT(line_count > 0);
+    const Array& tokens_seen_array = Array::Handle(tokens_seen());
+    intptr_t token_count = tokens_seen_array.Length();
+    int token_idx = 0;

[Kevin Millikin (Google), 2017/01/24 13:44:13]

You can also spell out index.

[jensj, 2017/01/25 12:52:22]

Done.

+    int last_line = -1;
 
     for (int i = 0; i < line_count; i++) {

[Kevin Millikin (Google), 2017/01/24 13:44:13]

Instead of i, it's clearer to use the name 'line_index' to keep the indexes
obviously parallel and distinct.

[jensj, 2017/01/25 12:52:22]

Done.

-      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.
+      intptr_t start = value.Value();
+      // Output the rest of the tokens if we have no next line.
+      intptr_t end = LONG_MAX;

[Kevin Millikin (Google), 2017/01/24 13:44:13]

INTPTR_MAX

[jensj, 2017/01/25 12:52:22]

Done.

+      if (i + 1 < line_count) {
+        value ^= line_starts_array.At(i + 1);
+        end = value.Value();
+      }
+      while (token_idx < token_count) {
+        value ^= tokens_seen_array.At(token_idx);
+        intptr_t seen = value.Value();

[Kevin Millikin (Google), 2017/01/24 13:44:13]

seen ==> debug_position ?

[jensj, 2017/01/25 12:52:22]

Done.

+        if (seen == -1) {

[Kevin Millikin (Google), 2017/01/24 13:44:13]

Can we just eliminate the -1 entries, or do we need them?

[jensj, 2017/01/25 12:52:22]

I'll move the check to the recording of the entries instead.

+          ++token_idx;
+          continue;
+        }
+        if (seen >= end) break;
+
+        if (i != last_line) {

[Kevin Millikin (Google), 2017/01/24 13:44:13]

last_line is just used to detect the first debug position on the line that is
not -1, right?  We don't actually use the value for anything.  I find it clearer
to have something like:

bool first = true;
while (token_index < token_count) {
  ...
  if (first) {
    ...
    first = false;
  }
  ...
}

[jensj, 2017/01/25 12:52:22]

It was done to look like the non-kernel version. I'll rewrite.

+          info.Add(line_separator);  // New line.
+          value = Smi::New(i + 1);   // Line number.
+          info.Add(value);
+          last_line = i;
+        }
+
+        value ^= tokens_seen_array.At(token_idx);
+        info.Add(value);                     // Token position.
+        value = Smi::New(seen - start + 1);  // Column.
+        info.Add(value);
+        ++token_idx;
+      }
     }
     return info.raw();
   }
@@ -8974,6 +9001,16 @@ void Script::set_line_starts(const Array& value) const {
 }
 
 
+void Script::set_tokens_seen(const Array& value) const {
+  StorePointer(&raw_ptr()->tokens_seen_, value.raw());
+}
+
+
+void Script::set_yields_seen(const Array& value) const {
+  StorePointer(&raw_ptr()->yields_seen_, value.raw());
+}
+
+
 void Script::set_kind(RawScript::Kind value) const {
   StoreNonPointer(&raw_ptr()->kind_, value);
 }
@@ -9064,6 +9101,8 @@ 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;