michael@0: // Two Environments nested in the same runtime scope share the correct tail of their parent chains.
michael@0: 
michael@0: // The compiler must be allowed to elide empty scopes and so forth, so this
michael@0: // test does not check the number of unshared Environments. Instead, each test
michael@0: // case identifies the expected innermost shared scope by the name of a
michael@0: // variable in it.
michael@0: 
michael@0: var g = newGlobal();
michael@0: g.eval("function h() { debugger; }");
michael@0: var dbg = Debugger(g);
michael@0: var hits, name, shared, unshared;
michael@0: dbg.onDebuggerStatement = function (hframe) {
michael@0:     var frame = hframe.older;
michael@0: 
michael@0:     // Find name in frame.environment.
michael@0:     var env, child = null;
michael@0:     for (env = frame.environment; env !== null; env = env.parent) {
michael@0:         if (env.names().indexOf(name) != -1)
michael@0:             break;
michael@0:         child = env;
michael@0:     }
michael@0:     assertEq(env !== null, true, "expected '" + name + "' to be in scope");
michael@0:     assertEq(env, frame.environment.find(name),
michael@0:              "env.find should find the same frame as the written out search");
michael@0: 
michael@0:     if (hits === 0) {
michael@0:         // First hit.
michael@0:         shared = env;
michael@0:         unshared = child;
michael@0:     } else {
michael@0:         // Subsequent hit.
michael@0:         assertEq(env, shared, "the environment containing '" + name + "' should be shared");
michael@0:         assertEq(child === null || unshared === null || unshared !== child, true,
michael@0:                 "environments nested within the one containing '" + name + "' should not be shared");
michael@0:     }
michael@0:     hits++;
michael@0: };
michael@0: 
michael@0: function test(sharedName, expectedHits, code) {
michael@0:     hits = 0;
michael@0:     name = sharedName;
michael@0:     shared = unshared = undefined;
michael@0:     g.eval(code);
michael@0:     assertEq(hits, expectedHits);
michael@0: }
michael@0: 
michael@0: // Basic test cases.
michael@0: //
michael@0: // (The stray "a = b" assignments in these tests are to inhibit the flat closure
michael@0: // optimization, which Environments expose. There's nothing really wrong with
michael@0: // the optimization or with the debugger exposing it, but that's not what we
michael@0: // want to test here.)
michael@0: 
michael@0: test("q", 2, "var q = function (a) { h(); }; q(1); q(2);");
michael@0: test("a", 2, "q = function (a) { (function (b) { h(); a = b; })(2); h(); }; q(1);");
michael@0: test("a", 2, "q = function (a) { h(); return function (b) { h(); a = b; }; }; q(1)(2);");
michael@0: test("n", 3, "q = function (n) { for (var i = 0; i < n; i++) { let (j = i) { h(); } } }; q(3);");
michael@0: 
michael@0: // A function with long dynamic and static chains.
michael@0: var N = 80;
michael@0: 
michael@0: var code = "function f" + N + "(a" + N + ") {\neval('a0 + a1'); h();\n}\n";
michael@0: for (var i = N; --i >= 0;) {
michael@0:     var call = "f" + (i + 1) + "(a" + i + " - 1);\n";
michael@0:     code = ("function f" + i + "(a" + i + ") {\n" +
michael@0:             code +
michael@0:             call +
michael@0:             "if (a" + i + " === 0) " + call +
michael@0:             "}\n");
michael@0: }
michael@0: 
michael@0: g.eval(code);
michael@0: test("a0", 2, "f0(0);");
michael@0: test("a17", 2, "f0(17);");
michael@0: test("a" + (N-2), 2, "f0(" + (N-2) + ");");
michael@0: test("a" + (N-1), 2, "f0(" + (N-1) + ");");
michael@0: 
michael@0: // A function with a short dynamic chain and a long static chain.
michael@0: N = 60;
michael@0: 
michael@0: function DeepStaticShallowDynamic(i, n) {
michael@0:     var code = "function f" + i + "(a" + i + ") {\n";
michael@0:     if (i >= n)
michael@0:         code += "eval('a1 + a2'); h();\n";
michael@0:     else
michael@0:         code += "return " + DeepStaticShallowDynamic(i+1, n) + ";\n";
michael@0:     code += "}";
michael@0:     return code;
michael@0: }
michael@0: g.eval(DeepStaticShallowDynamic(1, N));
michael@0: 
michael@0: function range(start, stop) {
michael@0:     for (var i = start; i < stop; i++)
michael@0:         yield i;
michael@0: }
michael@0: 
michael@0: function DSSDsplit(s) {
michael@0:     return ("var mid = f1" + ["(" + i + ")" for (i in range(0, s))].join("") + ";\n" +
michael@0:             "mid" +          ["(" + i + ")" for (i in range(s, N))].join("") + ";\n" +
michael@0:             "mid" +          ["(" + i + ")" for (i in range(s, N))].join("") + ";\n");
michael@0: }
michael@0: 
michael@0: test("a1", 2, DSSDsplit(1));
michael@0: test("a17", 2, DSSDsplit(17));
michael@0: test("a" + (N-2), 2, DSSDsplit(N-2));
michael@0: test("a" + (N-1), 2, DSSDsplit(N-1));