tor-browser

The Tor Browser
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Debugger-onEnterFrame-resumption-05.js (3177B)

      1 // Exercise the call to ScriptDebugPrologue in js_InternalInterpret.
      2 
      3 // This may change, but as of this writing, inline caches (ICs) are
      4 // disabled in debug mode, and those are the only users of the out-of-line entry
      5 // points for JIT code (arityCheckEntry, argsCheckEntry, fastEntry); debug
      6 // mode uses only invokeEntry. This means most of the bytecode tails in
      7 // js_InternalInterpret that might call ScriptPrologue or ScriptEpilogue are
      8 // unreachable in debug mode: they're only called from the out-of-line entry
      9 // points.
     10 //
     11 // The exception is REJOIN_THIS_PROTOTYPE, which can be reached reliably if you
     12 // add a JS_GC call to stubs::GetPropNoCache. JIT code calls that stub to
     13 // retrieve the 'prototype' property of a function called as a constructor, if
     14 // TI can't establish the exact identity of that prototype's value at compile
     15 // time. Thus the preoccupation with constructors here.
     16 
     17 load(libdir + "asserts.js");
     18 
     19 var debuggee = newGlobal({newCompartment: true});
     20 var dbg = Debugger(debuggee);
     21 var hits, savedFrame;
     22 
     23 // Allow the constructor to return normally.
     24 dbg.onEnterFrame = function (frame) {
     25    hits++;
     26    if (frame.constructing) {
     27        savedFrame = frame;
     28        assertEq(savedFrame.onStack, true);
     29        return undefined;
     30    }
     31    return undefined;
     32 };
     33 hits = 0;
     34 debuggee.hits = 0;
     35 savedFrame = undefined;
     36 assertEq(typeof debuggee.eval("function f(){ hits++; } f.prototype = {}; new f;"), "object");
     37 assertEq(hits, 2);
     38 assertEq(savedFrame.onStack, false);
     39 assertEq(debuggee.hits, 1);
     40 
     41 // Force an early return from the constructor.
     42 dbg.onEnterFrame = function (frame) {
     43    hits++;
     44    if (frame.constructing) {
     45        savedFrame = frame;
     46        assertEq(savedFrame.onStack, true);
     47        return { return: "pass" };
     48    }
     49    return undefined;
     50 };
     51 hits = 0;
     52 debuggee.hits = 0;
     53 savedFrame = undefined;
     54 assertEq(typeof debuggee.eval("function f(){ hits++; } f.prototype = {}; new f;"), "object");
     55 assertEq(hits, 2);
     56 assertEq(savedFrame.onStack, false);
     57 assertEq(debuggee.hits, 0);
     58 
     59 // Force the constructor to throw an exception.
     60 dbg.onEnterFrame = function (frame) {
     61    hits++;
     62    if (frame.constructing) {
     63        savedFrame = frame;
     64        assertEq(savedFrame.onStack, true);
     65        return { throw: "pass" };
     66    }
     67    return undefined;
     68 };
     69 hits = 0;
     70 debuggee.hits = 0;
     71 savedFrame = undefined;
     72 assertThrowsValue(function () {
     73                      debuggee.eval("function f(){ hits++ } f.prototype = {}; new f;");
     74                  }, "pass");
     75 assertEq(hits, 2);
     76 assertEq(savedFrame.onStack, false);
     77 assertEq(debuggee.hits, 0);
     78 
     79 // Ensure that forcing an early return only returns from one JS call.
     80 debuggee.eval("function g() { var result = new f; g_hits++; return result; }");
     81 dbg.onEnterFrame = function (frame) {
     82    hits++;
     83    if (frame.constructing) {
     84        savedFrame = frame;
     85        assertEq(savedFrame.onStack, true);
     86        return { return: "pass" };
     87    }
     88    return undefined;
     89 };
     90 hits = 0;
     91 debuggee.hits = 0;
     92 debuggee.g_hits = 0;
     93 savedFrame = undefined;
     94 assertEq(typeof debuggee.eval("g();"), "object");
     95 assertEq(hits, 3);
     96 assertEq(savedFrame.onStack, false);
     97 assertEq(debuggee.hits, 0);
     98 assertEq(debuggee.g_hits, 1);