[kernel] Offsets on loops

pkg/kernel/lib/ast.dart

Index: pkg/kernel/lib/ast.dart
diff --git a/pkg/kernel/lib/ast.dart b/pkg/kernel/lib/ast.dart
index be31d44683f422878de898e67f0bb133699aba84..7afda0c84ed66e7fdd65b766b0a9c59dc66eac6c 100644
--- a/pkg/kernel/lib/ast.dart
+++ b/pkg/kernel/lib/ast.dart
@@ -3432,6 +3432,12 @@ class ForStatement extends Statement {
 }
 
 class ForInStatement extends Statement {
+  /// Offset in the source file it comes from.
+  ///
+  /// Valid values are from 0 and up, or -1 ([TreeNode.noOffset]) if the file
+  /// offset is not available (this is the default if none is specifically set).
+  int bodyOffset = TreeNode.noOffset;

[ahe, 2017/08/08 11:38:50]

Why is the bodyOffset different from body.fileOffset?

[jensj, 2017/08/08 11:54:53]

As I recall I had to add that because we don't have offsets on everything. So
body.fileOffset might not go into the dill file, but we need the position to
reproduce the debugging behavior of the non-kernel pipeline.

[ahe, 2017/08/08 11:58:03]

Can't we make sure that we have positions on all those other things? It seems
like a bug if we have statements that lack a position, or am I missing
something?

+
   VariableDeclaration variable; // Has no initializer.
   Expression iterable;
   Statement body;