08f68102f8
Declare Variables with a name and position, rather than by passing through a VariableProxy. This allows us to not create dummy proxies for things like function declarations, and allows us to consider those declarations unused. As a side-effect, we also have to check if a variable is unused in the bytecode generator (as it will no longer be allocated), and we end up skip generating code/SFIs for dead variables/functions. Change-Id: I4c2c872473f23e124f9456b4b92f87159658f8e0 Reviewed-on: https://chromium-review.googlesource.com/c/1414916 Commit-Queue: Leszek Swirski <leszeks@chromium.org> Reviewed-by: Yang Guo <yangguo@chromium.org> Reviewed-by: Toon Verwaest <verwaest@chromium.org> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org> Cr-Commit-Position: refs/heads/master@{#59088}
58 lines
1.5 KiB
JavaScript
58 lines
1.5 KiB
JavaScript
// Copyright 2014 the V8 project authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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// Flags: --no-always-opt
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Debug = debug.Debug;
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var step = 0;
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var exception = null;
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function listener(event, exec_state, event_data, data) {
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if (event != Debug.DebugEvent.Break) return;
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try {
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if (step == 0) {
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assertEquals("error", exec_state.frame(0).evaluate("e").value());
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exec_state.frame(0).evaluate("write_0('foo')");
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exec_state.frame(0).evaluate("write_1('modified')");
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} else {
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assertEquals("argument", exec_state.frame(0).evaluate("e").value());
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exec_state.frame(0).evaluate("write_2('bar')");
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}
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step++;
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} catch (e) {
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print(e + e.stack);
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exception = e;
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}
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}
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Debug.setListener(listener);
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function f(e, x) {
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try {
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throw "error";
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} catch(e) {
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// In ES2015 hoisting semantics, 'x' binds to the argument
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// and 'e' binds to the exception.
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function write_0(v) { e = v }
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function write_1(v) { x = v }
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// Make sure write_0 and write_1 are 'used' so that they are visible to the
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// debugger.
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write_0, write_1;
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debugger;
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assertEquals("foo", e); // overwritten by the debugger
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}
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assertEquals("argument", e); // debugger did not overwrite
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function write_2(v) { e = v }
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// Make sure write_2 is 'used' so that it is visible to the debugger.
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write_2;
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debugger;
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assertEquals("bar", e);
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assertEquals("modified", x);
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}
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f("argument")
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assertNull(exception);
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assertEquals(2, step);
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