[debugger] muting break positions should work for the entire statement.

A statement could have several break positions. The entire statement
should be considered muted if break points across all these break
positions evaluate to false.

R=verwaest@chromium.org
BUG=chromium:429167
LOG=N

Review URL: https://codereview.chromium.org/1615903002

Cr-Commit-Position: refs/heads/master@{#33522}

src/debug/debug.cc

@@ -168,6 +168,18 @@ void BreakLocation::FromAddressSameStatement(Handle<DebugInfo> debug_info,
 }
 
 
+// Find all break locations with the given statement position.
+void BreakLocation::AllForStatementPosition(Handle<DebugInfo> debug_info,
+                                            int statement_position,
+                                            List<BreakLocation>* result_out) {
+  for (Iterator it(debug_info, ALL_BREAK_LOCATIONS); !it.Done(); it.Next()) {
+    if (it.statement_position() == statement_position) {
+      result_out->Add(it.GetBreakLocation());
+    }
+  }
+}
+
+
 int BreakLocation::BreakIndexFromAddress(Handle<DebugInfo> debug_info,
                                          Address pc) {
   // Run through all break points to locate the one closest to the address.
@@ -536,11 +548,11 @@ Handle<Object> Debug::CheckBreakPoints(BreakLocation* location,
 
 
 bool Debug::IsMutedAtCurrentLocation(JavaScriptFrame* frame) {
-  // A break location is considered muted if the break location has break
-  // points, but their conditions all evaluate to false.
-  // Aside from not triggering a debug break event at the break location,
-  // we also do not trigger one for debugger statements, nor an exception event
-  // on exception at this location.
+  // A break location is considered muted if break locations on the current
+  // statement have at least one break point, and all of these break points
+  // evaluate to false. Aside from not triggering a debug break event at the
+  // break location, we also do not trigger one for debugger statements, nor
+  // an exception event on exception at this location.
   Object* fun = frame->function();
   if (!fun->IsJSFunction()) return false;
   JSFunction* function = JSFunction::cast(fun);
@@ -550,10 +562,19 @@ bool Debug::IsMutedAtCurrentLocation(JavaScriptFrame* frame) {
   // Enter the debugger.
   DebugScope debug_scope(this);
   if (debug_scope.failed()) return false;
-  BreakLocation location = BreakLocation::FromFrame(debug_info, frame);
-  bool has_break_points;
-  Handle<Object> check_result = CheckBreakPoints(&location, &has_break_points);
-  return has_break_points && check_result->IsUndefined();
+  BreakLocation current_position = BreakLocation::FromFrame(debug_info, frame);
+  List<BreakLocation> break_locations;
+  BreakLocation::AllForStatementPosition(
+      debug_info, current_position.statement_position(), &break_locations);
+  bool has_break_points_at_all = false;
+  for (int i = 0; i < break_locations.length(); i++) {
+    bool has_break_points;
+    Handle<Object> check_result =
+        CheckBreakPoints(&break_locations[i], &has_break_points);
+    has_break_points_at_all |= has_break_points;
+    if (has_break_points && !check_result->IsUndefined()) return false;
+  }
+  return has_break_points_at_all;
 }
 
 

src/debug/debug.h

@@ -76,6 +76,10 @@ class BreakLocation {
   static void FromAddressSameStatement(Handle<DebugInfo> debug_info, Address pc,
                                        List<BreakLocation>* result_out);
 
+  static void AllForStatementPosition(Handle<DebugInfo> debug_info,
+                                      int statement_position,
+                                      List<BreakLocation>* result_out);
+
   static BreakLocation FromPosition(Handle<DebugInfo> debug_info, int position,
                                     BreakPositionAlignment alignment);
 

test/mjsunit/debug-negative-break-points.js

@@ -33,6 +33,14 @@ function g(x) {
   }
 }
 
+function h(x) {
+  var a = undefined;
+  try {
+    var x = a();
+  } catch (e) {
+  }
+}
+
 Debug.setListener(listener);
 
 assertCount(0, 0);
@@ -79,5 +87,13 @@ assertCount(8, 4);
 g(0);
 assertCount(8, 4);
 
+h(0);
+assertCount(8, 5);
+Debug.setBreakPoint(h, 3, 0, "x > 0");
+h(1);
+assertCount(9, 6);
+h(0);
+assertCount(9, 6);
+
 Debug.clearBreakOnException();
 Debug.setListener(null);