{"action":"closed","issue":{"url":"https://api.github.com/repos/libuv/libuv/issues/454","labels_url":"https://api.github.com/repos/libuv/libuv/issues/454/labels{/name}","comments_url":"https://api.github.com/repos/libuv/libuv/issues/454/comments","events_url":"https://api.github.com/repos/libuv/libuv/issues/454/events","html_url":"https://github.com/libuv/libuv/issues/454","id":97238139,"number":454,"title":"Variable length array folded to constant array as an extension on OS X","user":{"login":"jen20","id":548524,"avatar_url":"https://avatars.githubusercontent.com/u/548524?v=3","gravatar_id":"","url":"https://api.github.com/users/jen20","html_url":"https://github.com/jen20","followers_url":"https://api.github.com/users/jen20/followers","following_url":"https://api.github.com/users/jen20/following{/other_user}","gists_url":"https://api.github.com/users/jen20/gists{/gist_id}","starred_url":"https://api.github.com/users/jen20/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jen20/subscriptions","organizations_url":"https://api.github.com/users/jen20/orgs","repos_url":"https://api.github.com/users/jen20/repos","events_url":"https://api.github.com/users/jen20/events{/privacy}","received_events_url":"https://api.github.com/users/jen20/received_events","type":"User","site_admin":false},"labels":[],"state":"closed","locked":false,"assignee":null,"milestone":null,"comments":1,"created_at":"2015-07-25T16:43:43Z","updated_at":"2015-07-27T09:49:23Z","closed_at":"2015-07-27T09:49:23Z","body":"Building with Clang on OS X 10.10.4, gives the following warning about folding variable array lengths:\r\n\r\n```\r\n~/libuv/libuv-1.6.1/src/unix/stream.c:1079:19: warning: variable length array\r\n      folded to constant array as an extension [-Wgnu-folding-constant]\r\n  char cmsg_space[CMSG_SPACE(UV__CMSG_FD_SIZE)];\r\n                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~\r\n/usr/include/sys/socket.h:522:24: note: expanded from macro 'CMSG_SPACE'\r\n#define CMSG_SPACE(l)           (__DARWIN_ALIGN32(sizeof(struct cmsghdr)) + __DARWIN_ALIGN32(l))\r\n                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\r\n~/libuv/libuv-1.6.1/src/unix/stream.c:1079:19: note: cast that performs the\r\n      conversions of a reinterpret_cast is not allowed in a constant expression\r\n/usr/include/sys/socket.h:522:25: note: expanded from macro 'CMSG_SPACE'\r\n#define CMSG_SPACE(l)           (__DARWIN_ALIGN32(sizeof(struct cmsghdr)) + __DARWIN_ALIGN32(l))\r\n                                 ^\r\n/usr/include/i386/_param.h:43:42: note: expanded from macro '__DARWIN_ALIGN32'\r\n#define       __DARWIN_ALIGN32(p)       ((__darwin_size_t)((char *)(__darwin_size_t)(p) + __DARWIN_ALIGNBYTES32...\r\n                                         ^\r\n1 warning generated.\r\n```\r\n\r\nThe version of Clang/LLVM in use is:\r\n\r\n```\r\n$ gcc --version\r\nApple LLVM version 6.1.0 (clang-602.0.53) (based on LLVM 3.6.0svn)\r\nTarget: x86_64-apple-darwin14.4.0\r\nThread model: posix\r\n```\r\n\r\nIs there any harm in muting this with appropriate compiler flags?"}}