code review 137020043: cmd/cc: generate error if #pragma pack off does anything

src/pkg/runtime/netpoll_epoll.c

 // Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 // +build linux
 
 #include "runtime.h"
 #include "defs_GOOS_GOARCH.h"
 
 int32   runtime·epollcreate(int32 size);
@@ skipping 19 matching lines @@
         runtime·throw("netpollinit: failed to create descriptor");
 }
 
 int32
 runtime·netpollopen(uintptr fd, PollDesc *pd)
 {
         EpollEvent ev;
         int32 res;
 
         ev.events = EPOLLIN|EPOLLOUT|EPOLLRDHUP|EPOLLET;
-        ev.data = (uint64)pd;
+        *(uintptr*)ev.data = (uintptr)pd;
         res = runtime·epollctl(epfd, EPOLL_CTL_ADD, (int32)fd, &ev);
         return -res;
 }
 
 int32
 runtime·netpollclose(uintptr fd)
 {
         EpollEvent ev;
         int32 res;
 
@@ skipping 43 matching lines @@
                         mode += 'r';
                 if(ev->events & (EPOLLOUT|EPOLLHUP|EPOLLERR))
                         mode += 'w';
                 if(mode)
                         runtime·netpollready(&gp, (void*)ev->data, mode);
         }
         if(block && gp == nil)
                 goto retry;
         return gp;
 }