[V8] Add flag to avoid breakpoint relocation

Add a flag that prevents v8 from relocating breakpoints across
line boundaries.

Change-Id: I7caafdf91ff161c3566078685daef56526bc5926
Reviewed-by: Simon Hausmann <simon.hausmann@nokia.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

5 files changed, 72 insertions, 0 deletions

diff --git a/src/3rdparty/v8/src/debug-debugger.js b/src/3rdparty/v8/src/debug-debugger.js
index 7787312..6c94c15 100644
--- a/src/3rdparty/v8/src/debug-debugger.js
+++ b/src/3rdparty/v8/src/debug-debugger.js
@@ -448,6 +448,11 @@ ScriptBreakPoint.prototype.set = function (script) {
     actual_position = position;
   }
   var actual_location = script.locationFromPosition(actual_position, true);
+  // Check for any relocation and compare it with the breakpoint_relocation flag
+  if (actual_location.line != line && !%AllowBreakPointRelocation()) {
+    %ClearBreakPoint(break_point);
+    return;
+  }
   break_point.actual_location = { line: actual_location.line,
                                   column: actual_location.column,
                                   script_id: script.id };
diff --git a/src/3rdparty/v8/src/flag-definitions.h b/src/3rdparty/v8/src/flag-definitions.h
index dcc6c2c..135833b 100644
--- a/src/3rdparty/v8/src/flag-definitions.h
+++ b/src/3rdparty/v8/src/flag-definitions.h
@@ -387,6 +387,7 @@ DEFINE_implication(trace_array_abuse, trace_external_array_abuse)
 DEFINE_bool(debugger_auto_break, true,
             "automatically set the debug break flag when debugger commands are "
             "in the queue")
+DEFINE_bool(breakpoint_relocation, true, "relocate breakpoints to the next executable line")
 DEFINE_bool(enable_liveedit, true, "enable liveedit experimental feature")
 DEFINE_bool(break_on_abort, true, "always cause a debug break before aborting")
 
diff --git a/src/3rdparty/v8/src/runtime.cc b/src/3rdparty/v8/src/runtime.cc
index c465a5b..191e717 100644
--- a/src/3rdparty/v8/src/runtime.cc
+++ b/src/3rdparty/v8/src/runtime.cc
@@ -11637,6 +11637,12 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_GetBreakLocations) {
 }
 
 
+// Return the value of breakpoint_relocation flag
+RUNTIME_FUNCTION(MaybeObject*, Runtime_AllowBreakPointRelocation) {
+  return Smi::FromInt(FLAG_breakpoint_relocation);
+}
+
+
 // Set a break point in a function.
 // args[0]: function
 // args[1]: number: break source position (within the function source)
diff --git a/src/3rdparty/v8/src/runtime.h b/src/3rdparty/v8/src/runtime.h
index 036264e..74cc2d8 100644
--- a/src/3rdparty/v8/src/runtime.h
+++ b/src/3rdparty/v8/src/runtime.h
@@ -447,6 +447,7 @@ namespace internal {
   F(GetThreadDetails, 2, 1) \
   F(SetDisableBreak, 1, 1) \
   F(GetBreakLocations, 1, 1) \
+  F(AllowBreakPointRelocation, 0, 1) \
   F(SetFunctionBreakPoint, 3, 1) \
   F(SetScriptBreakPoint, 3, 1) \
   F(ClearBreakPoint, 1, 1) \
diff --git a/src/3rdparty/v8/test/cctest/test-debug.cc b/src/3rdparty/v8/test/cctest/test-debug.cc
index 8d37440..51eb203 100644
--- a/src/3rdparty/v8/test/cctest/test-debug.cc
+++ b/src/3rdparty/v8/test/cctest/test-debug.cc
@@ -2304,6 +2304,65 @@ TEST(ScriptBreakPointTopLevelCrash) {
   CheckDebuggerUnloaded();
 }
 
+// Test that breakpoint_relocation flag is honored
+TEST(ScriptBreakPointNoRelocation) {
+    i::FLAG_breakpoint_relocation = false;
+
+    v8::HandleScope scope;
+    DebugLocalContext env;
+    env.ExposeDebug();
+
+    // Create a function for checking the function when hitting a break point.
+    frame_function_name = CompileFunction(&env,
+                                          frame_function_name_source,
+                                          "frame_function_name");
+
+    v8::Debug::SetDebugEventListener(DebugEventBreakPointHitCount,
+                                     v8::Undefined());
+
+    v8::Local<v8::String> script1 = v8::String::New(
+      "a = 0                      // line 0\n"
+      "                           // line 1\n"
+      "                           // line 2\n"
+      "                           // line 3\n"
+      "function f() {             // line 4\n"
+      "  return 0;                // line 5\n"
+      "}                          // line 6");
+
+    // Set the script break point on the empty line
+    SetScriptBreakPointByNameFromJS("test.html", 2, -1);
+
+    // Compile the script and call the function.
+    v8::ScriptOrigin origin(v8::String::New("test.html"), v8::Integer::New(0));
+    v8::Script::Compile(script1, &origin)->Run();
+    v8::Local<v8::Function> f =
+        v8::Local<v8::Function>::Cast(env->Global()->Get(v8::String::New("f")));
+    f->Call(env->Global(), 0, NULL);
+
+    // Check that a break point was not hit
+    CHECK_EQ(0, break_point_hit_count);
+
+    v8::Local<v8::String> script2 = v8::String::New(
+      "a = 0                      // line 0\n"
+      "function g() {             // line 1\n"
+      "  return 0;                // line 2\n"
+      "}                          // line 3\n"
+      "function f() {             // line 4\n"
+      "  return 0;                // line 5\n"
+      "}                          // line 6");
+
+    // Compile the script and call the new function
+    v8::Script::Compile(script2, &origin)->Run();
+    v8::Local<v8::Function> g =
+        v8::Local<v8::Function>::Cast(env->Global()->Get(v8::String::New("g")));
+    g->Call(env->Global(), 0, NULL);
+
+    // Check that a break point was not hit
+    CHECK_EQ(1, break_point_hit_count);
+
+    v8::Debug::SetDebugEventListener(NULL);
+    CheckDebuggerUnloaded();
+}
 
 // Test that it is possible to remove the last break point for a function
 // inside the break handling of that break point.