Win64: Fix a pointer truncation bug in nspr.

nspr/pr/src/threads/combined/pruthr.c

 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "primpl.h"
 #include <signal.h>
 #include <string.h>
 
 #if defined(WIN95)                                                                         
@@ skipping 55 matching lines @@
     PRThreadStack *stack;
 
     PR_ASSERT(priority == PR_PRIORITY_NORMAL);
 
     _pr_terminationCVLock = PR_NewLock();
     _pr_activeLock = PR_NewLock();
 
 #ifndef HAVE_CUSTOM_USER_THREADS
     stack = PR_NEWZAP(PRThreadStack);
 #ifdef HAVE_STACK_GROWING_UP
-    stack->stackTop = (char*) ((((long)&type) >> _pr_pageShift)
+    stack->stackTop = (char*) ((((intptr_t)&type) >> _pr_pageShift)

[wtc, 2014/12/01 18:34:02]

In the NSPR upstream, I changed intptr_t to PRWord, which is a (poorly named)
NSPR type commonly used for this purpose. In Chromium it is fine to just use
intptr_t.

PRWord and intptr_t are both defined as __int64 in WIN64. Here is Visual C++
2010's definition of intptr_t:

#ifndef _INTPTR_T_DEFINED
 #define _INTPTR_T_DEFINED
 #ifdef _WIN64
typedef __int64 intptr_t;
 #else /* _WIN64 */
typedef _W64 int intptr_t;
 #endif /* _WIN64 */
#endif /* _INTPTR_T_DEFINED */

                   << _pr_pageShift);
 #else
 #if defined(SOLARIS) || defined (UNIXWARE) && defined (USR_SVR4_THREADS)
     stack->stackTop = (char*) &thread;
 #else
-    stack->stackTop = (char*) ((((long)&type + _pr_pageSize - 1)
+    stack->stackTop = (char*) ((((intptr_t)&type + _pr_pageSize - 1)
                 >> _pr_pageShift) << _pr_pageShift);
 #endif
 #endif
 #else
     /* If stack is NULL, we're using custom user threads like NT fibers. */
     stack = PR_NEWZAP(PRThreadStack);
     if (stack) {
         stack->stackSize = 0;
         _PR_InitializeNativeStack(stack);
     }
@@ skipping 74 matching lines @@
 */
 static void _PR_InitializeNativeStack(PRThreadStack *ts)
 {
     if( ts && (ts->stackTop == 0) ) {
         ts->allocSize = ts->stackSize;
 
         /*
         ** Setup stackTop and stackBottom values.
         */
 #ifdef HAVE_STACK_GROWING_UP
-    ts->allocBase = (char*) ((((long)&ts) >> _pr_pageShift)
+    ts->allocBase = (char*) ((((intptr_t)&ts) >> _pr_pageShift)
                   << _pr_pageShift);
         ts->stackBottom = ts->allocBase + ts->stackSize;
         ts->stackTop = ts->allocBase;
 #else
-        ts->allocBase = (char*) ((((long)&ts + _pr_pageSize - 1)
+        ts->allocBase = (char*) ((((intptr_t)&ts + _pr_pageSize - 1)
                 >> _pr_pageShift) << _pr_pageShift);
         ts->stackTop    = ts->allocBase;
         ts->stackBottom = ts->allocBase - ts->stackSize;
 #endif
     }
 }
 
 void _PR_NotifyJoinWaiters(PRThread *thread)
 {
     /*
@@ skipping 1687 matching lines @@
     _PR_RUNQ_LOCK(cpu);
     _PR_ADD_RUNQ(thread, cpu, pri);
     _PR_RUNQ_UNLOCK(cpu);
     if (!_PR_IS_NATIVE_THREAD(me) && (cpu == me->cpu)) {
         if (pri > me->priority) {
             _PR_SET_RESCHED_FLAG();
         }
     }
 #endif
 }