The Tor Browser: js/xpconnect/src/XPCDebug.cpp@b8a032363ba2

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

     1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

     2 /* vim: set ts=8 sts=4 et sw=4 tw=99: */

     3 /* This Source Code Form is subject to the terms of the Mozilla Public

     4  * License, v. 2.0. If a copy of the MPL was not distributed with this

     5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     7 #include "xpcprivate.h"

     8 #include "jsprf.h"

     9 #include "js/OldDebugAPI.h"

    11 #ifdef XP_WIN

    12 #include <windows.h>

    13 #endif

    15 static void DebugDump(const char* fmt, ...)

    16 {

    17   char buffer[2048];

    18   va_list ap;

    19   va_start(ap, fmt);

    20 #ifdef XPWIN

    21   _vsnprintf(buffer, sizeof(buffer), fmt, ap);

    22 #else

    23   vsnprintf(buffer, sizeof(buffer), fmt, ap);

    24 #endif

    25   buffer[sizeof(buffer)-1] = '\0';

    26   va_end(ap);

    27 #ifdef XP_WIN

    28   if (IsDebuggerPresent()) {

    29     OutputDebugStringA(buffer);

    30   }

    31 #endif

    32   printf("%s", buffer);

    33 }

    35 bool

    36 xpc_DumpJSStack(JSContext* cx, bool showArgs, bool showLocals, bool showThisProps)

    37 {

    38     if (char* buf = xpc_PrintJSStack(cx, showArgs, showLocals, showThisProps)) {

    39         DebugDump("%s\n", buf);

    40         JS_smprintf_free(buf);

    41     }

    42     return true;

    43 }

    45 char*

    46 xpc_PrintJSStack(JSContext* cx, bool showArgs, bool showLocals,

    47                  bool showThisProps)

    48 {

    49     JS::AutoSaveExceptionState state(cx);

    51     char *buf = JS::FormatStackDump(cx, nullptr, showArgs, showLocals, showThisProps);

    52     if (!buf)

    53         DebugDump("%s", "Failed to format JavaScript stack for dump\n");

    55     state.restore();

    56     return buf;

    57 }

    59 /***************************************************************************/

    61 static void

    62 xpcDumpEvalErrorReporter(JSContext *cx, const char *message,

    63                          JSErrorReport *report)

    64 {

    65     DebugDump("Error: %s\n", message);

    66 }

    68 bool

    69 xpc_DumpEvalInJSStackFrame(JSContext* cx, uint32_t frameno, const char* text)

    70 {

    71     if (!cx || !text) {

    72         DebugDump("%s", "invalid params passed to xpc_DumpEvalInJSStackFrame!\n");

    73         return false;

    74     }

    76     DebugDump("js[%d]> %s\n", frameno, text);

    78     uint32_t num = 0;

    80     JSAbstractFramePtr frame = JSNullFramePtr();

    82     JSBrokenFrameIterator iter(cx);

    83     while (!iter.done()) {

    84         if (num == frameno) {

    85             frame = iter.abstractFramePtr();

    86             break;

    87         }

    88         ++iter;

    89         num++;

    90     }

    92     if (!frame) {

    93         DebugDump("%s", "invalid frame number!\n");

    94         return false;

    95     }

    97     JS::AutoSaveExceptionState exceptionState(cx);

    98     JSErrorReporter older = JS_SetErrorReporter(cx, xpcDumpEvalErrorReporter);

   100     JS::RootedValue rval(cx);

   101     JSString* str;

   102     JSAutoByteString bytes;

   103     if (frame.evaluateInStackFrame(cx, text, strlen(text), "eval", 1, &rval) &&

   104         nullptr != (str = ToString(cx, rval)) &&

   105         bytes.encodeLatin1(cx, str)) {

   106         DebugDump("%s\n", bytes.ptr());

   107     } else {

   108         DebugDump("%s", "eval failed!\n");

   109     }

   111     JS_SetErrorReporter(cx, older);

   112     exceptionState.restore();

   113     return true;

   114 }

   116 /***************************************************************************/

   118 JSTrapStatus

   119 xpc_DebuggerKeywordHandler(JSContext *cx, JSScript *script, jsbytecode *pc,

   120                            jsval *rval, void *closure)

   121 {

   122     static const char line[] =

   123     "------------------------------------------------------------------------\n";

   124     DebugDump("%s", line);

   125     DebugDump("%s", "Hit JavaScript \"debugger\" keyword. JS call stack...\n");

   126     xpc_DumpJSStack(cx, true, true, false);

   127     DebugDump("%s", line);

   128     return JSTRAP_CONTINUE;

   129 }

   131 bool xpc_InstallJSDebuggerKeywordHandler(JSRuntime* rt)

   132 {

   133     return JS_SetDebuggerHandler(rt, xpc_DebuggerKeywordHandler, nullptr);

   134 }

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