[ignition, debugger] correctly set position for return with elided bytecode.

test/unittests/interpreter/source-position-table-unittest.cc

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/interpreter/source-position-table.h"
 #include "test/unittests/test-utils.h"
 
 namespace v8 {
 namespace internal {
 namespace interpreter {
 
 class SourcePositionTableTest : public TestWithIsolateAndZone {
  public:
   SourcePositionTableTest() {}
   ~SourcePositionTableTest() override {}
 };
 
 // Some random offsets, mostly at 'suspicious' bit boundaries.
-static int offsets[] = {0,   1,   2,    3,    4,     30,      31,  32,
-                        33,  62,  63,   64,   65,    126,     127, 128,
-                        129, 250, 1000, 9999, 12000, 31415926};
+static int offsets[] = {0,   1,   2,    3,    4,     30,       31,      32,
+                        33,  62,  63,   64,   65,    126,      127,     128,
+                        129, 250, 1000, 9999, 12000, 31415926, 31415926};
 
 TEST_F(SourcePositionTableTest, EncodeStatement) {
   SourcePositionTableBuilder builder(isolate(), zone());
   for (int i = 0; i < arraysize(offsets); i++) {
     builder.AddStatementPosition(offsets[i], offsets[i]);
   }
 
   // To test correctness, we rely on the assertions in ToSourcePositionTable().
   // (Also below.)
   CHECK(!builder.ToSourcePositionTable().is_null());
 }
 
+TEST_F(SourcePositionTableTest, EncodeStatementOverwrite) {
+  SourcePositionTableBuilder builder(isolate(), zone());
+  for (int i = 0; i < arraysize(offsets); i++) {
+    builder.AddStatementPosition(
+        offsets[i], offsets[i],
+        SourcePositionTableBuilder::OVERWRITE_DUPLICATE);
+  }
+
+  // To test correctness, we rely on the assertions in ToSourcePositionTable().
+  // (Also below.)
+  CHECK(!builder.ToSourcePositionTable().is_null());
+}
+

[vogelheim, 2016/03/14 10:41:15]

Maybe a good test case would be to just add each offset 4 times, and alternate
OVERWRITE_DUPLICATE based on (i % 2), or so.

[Yang, 2016/03/14 11:32:34]

Done.

 TEST_F(SourcePositionTableTest, EncodeExpression) {
   SourcePositionTableBuilder builder(isolate(), zone());
   for (int i = 0; i < arraysize(offsets); i++) {
     builder.AddExpressionPosition(offsets[i], offsets[i]);
   }
   CHECK(!builder.ToSourcePositionTable().is_null());
 }
 
 TEST_F(SourcePositionTableTest, EncodeAscending) {
   SourcePositionTableBuilder builder(isolate(), zone());
@@ skipping 17 matching lines @@
       builder.AddExpressionPosition(accumulator, accumulator);
     }
   }
 
   CHECK(!builder.ToSourcePositionTable().is_null());
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8