v8/test/mjsunit/debug-step.js
yangguo d9fe836dd4 [debugger] fix break locations for assignments and return.
We used to emit debug break location on block entry. This cannot be
ported to the interpreted as we do not emit bytecode for block entry.
This made no sense to begin with though, but accidentally added
break locations for var declarations.

With this change, the debugger no longer breaks at var declarations
without initialization. This is in accordance with the fact that the
interpreter does not emit bytecode for uninitialized var declarations.

Also fix the bytecode to match full-codegen's behavior wrt return
positions:
- there is a break location before the return statement, with the source
  position of the return statement.
- right before the actual return, there is another break location. The
  source position points to the end of the function.

R=rmcilroy@chromium.org, vogelheim@chromium.org
TBR=rossberg@chromium.org
BUG=v8:4690
LOG=N

Review URL: https://codereview.chromium.org/1744123003

Cr-Commit-Position: refs/heads/master@{#34388}
2016-03-01 12:47:55 +00:00

73 lines
2.8 KiB
JavaScript

// Copyright 2008 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// Flags: --expose-debug-as debug
// Get the Debug object exposed from the debug context global object.
Debug = debug.Debug
// Simple debug event handler which first time hit will perform 1000 steps and
// second time hit will evaluate and store the value of "i". If requires that
// the global property "state" is initially zero.
var bp1, bp2;
function listener(event, exec_state, event_data, data) {
if (event == Debug.DebugEvent.Break) {
if (step_count > 0) {
exec_state.prepareStep(Debug.StepAction.StepIn);
step_count--;
} else {
result = exec_state.frame().evaluate("i").value();
// Clear the break point on line 2 if set.
if (bp2) {
Debug.clearBreakPoint(bp2);
}
}
}
};
// Add the debug event listener.
Debug.setListener(listener);
// Test debug event for break point.
function f() {
var i; // Line 1.
for (i = 0; i < 1000; i++) { // Line 2.
x = 1; // Line 3.
}
};
// Set a breakpoint on the for statement (line 1).
bp1 = Debug.setBreakPoint(f, 1);
// Check that performing 1000 steps will make i 333.
var step_count = 1000;
result = -1;
f();
assertEquals(333, result);
Debug.setListener(null);