# HG changeset patch
# User jbe
# Date 1474157961 -7200
# Node ID 77a7ca00ad34870ad9c0f85749ed336a0be9a180
# Parent  ff7eea59be93e496d3651a1ead6b9d56a71d0fca
Simplified error handling with new macro(s)

diff -r ff7eea59be93 -r 77a7ca00ad34 moonbridge_io.c
--- a/moonbridge_io.c	Sun Sep 18 00:59:31 2016 +0200
+++ b/moonbridge_io.c	Sun Sep 18 02:19:21 2016 +0200
@@ -42,9 +42,18 @@
 #define MOONBR_IO_LISTEN_BACKLOG 1024
 
 #define MOONBR_IO_STRERROR_R_MSG "Error detail unavailable due to noncompliant strerror_r() implementation"
-#define moonbr_io_errmsg() \
+#define moonbr_io_prepare_errmsg() \
   char errmsg[MOONBR_IO_MAXSTRERRORLEN] = MOONBR_IO_STRERROR_R_MSG; \
   strerror_r(errno, errmsg, MOONBR_IO_MAXSTRERRORLEN)
+#define moonbr_io_return_prepared_errmsg() \
+  lua_pushnil(L); \
+  lua_pushstring(L, errmsg); \
+  return 2
+#define moonbr_io_return_errmsg() \
+  do { \
+    moonbr_io_prepare_errmsg(); \
+    moonbr_io_return_prepared_errmsg(); \
+  } while (0)
 
 #define MOONBR_IO_HANDLE_MT_REGKEY "moonbridge_io_handle"
 #define MOONBR_IO_HANDLE_PUBLIC_MT_REGKEY "moonbridge_io_handle_public"
@@ -202,12 +211,7 @@
     return 2;
   }
   handle->readerr = 1;
-  if (moonbr_io_handle_set_nonblocking(L, handle, nonblocking)) {
-    moonbr_io_errmsg();
-    lua_pushnil(L);
-    lua_pushstring(L, errmsg);
-    return 2;
-  }
+  if (moonbr_io_handle_set_nonblocking(L, handle, nonblocking)) moonbr_io_return_errmsg();
   if (!drain) luaL_buffinit(L, &luabuf);
   while (1) {
     remaining = -1;
@@ -311,12 +315,7 @@
       handle->readerr = 0;
       return 2;
     }
-    if (bytesread < 0) {
-      moonbr_io_errmsg();
-      lua_pushnil(L);
-      lua_pushstring(L, errmsg);
-      return 2;
-    }
+    if (bytesread < 0) moonbr_io_return_errmsg();
     handle->readbufin = bytesread;
   }
 }
@@ -508,12 +507,7 @@
     return 2;
   }
   handle->writeerr = 1;
-  if (moonbr_io_handle_set_nonblocking(L, handle, nonblocking)) {
-    moonbr_io_errmsg();
-    lua_pushnil(L);
-    lua_pushstring(L, errmsg);
-    return 2;
-  }
+  if (moonbr_io_handle_set_nonblocking(L, handle, nonblocking)) moonbr_io_return_errmsg();
   top = lua_gettop(L);
   lua_getuservalue(L, 1);
   lua_getfield(L, -1, "writequeue");
@@ -548,12 +542,7 @@
         handle->writeqoff += MOONBR_IO_WRITEBUFLEN - handle->writebufin;
         handle->writebufin = MOONBR_IO_WRITEBUFLEN;
         while (handle->writebufout < MOONBR_IO_WRITEBUFLEN) {
-          if (moonbr_io_handle_set_nopush(L, handle, 1)) {
-            moonbr_io_errmsg();
-            lua_pushnil(L);
-            lua_pushstring(L, errmsg);
-            return 2;
-          }
+          if (moonbr_io_handle_set_nopush(L, handle, 1)) moonbr_io_return_errmsg();
 #ifdef MOONBR_IO_USE_TLS
           moonbr_io_write_tls(
             handle->writebuf + handle->writebufout,
@@ -568,24 +557,14 @@
           if (written < 0) {
             if (nonblocking && (errno == EAGAIN || errno == EWOULDBLOCK)) {
               goto moonbr_io_write_impl_block;
-            } else if (errno != EINTR) {
-              moonbr_io_errmsg();
-              lua_pushnil(L);
-              lua_pushstring(L, errmsg);
-              return 2;
-            }
+            } else if (errno != EINTR) moonbr_io_return_errmsg();
           } else {
             handle->writebufout += written;
             handle->writeleft -= written;
             if (handle->flushedleft) {
               if (written >= handle->flushedleft) {
                 handle->flushedleft = 0;
-                if (moonbr_io_handle_set_nopush(L, handle, 0)) {
-                  moonbr_io_errmsg();
-                  lua_pushnil(L);
-                  lua_pushstring(L, errmsg);
-                  return 2;
-                }
+                if (moonbr_io_handle_set_nopush(L, handle, 0)) moonbr_io_return_errmsg();
               } else {
                 handle->flushedleft -= written;
               }
@@ -602,12 +581,7 @@
     lua_rawseti(L, -2, handle->writeqout++);
   }
   while (handle->flushedleft) {
-    if (moonbr_io_handle_set_nopush(L, handle, 1)) {
-      moonbr_io_errmsg();
-      lua_pushnil(L);
-      lua_pushstring(L, errmsg);
-      return 2;
-    }
+    if (moonbr_io_handle_set_nopush(L, handle, 1)) moonbr_io_return_errmsg();
 #ifdef MOONBR_IO_USE_TLS
     moonbr_io_write_tls(
       handle->writebuf + handle->writebufout,
@@ -622,24 +596,14 @@
     if (written < 0) {
       if (nonblocking && (errno == EAGAIN || errno == EWOULDBLOCK)) {
         goto moonbr_io_write_impl_block;
-      } else if (errno != EINTR) {
-        moonbr_io_errmsg();
-        lua_pushnil(L);
-        lua_pushstring(L, errmsg);
-        return 2;
-      }
+      } else if (errno != EINTR) moonbr_io_return_errmsg();
     } else {
       handle->writebufout += written;
       handle->writeleft -= written;
       if (handle->flushedleft) {
         if (written >= handle->flushedleft) {
           handle->flushedleft = 0;
-          if (moonbr_io_handle_set_nopush(L, handle, 0)) {
-            moonbr_io_errmsg();
-            lua_pushnil(L);
-            lua_pushstring(L, errmsg);
-            return 2;
-          }
+          if (moonbr_io_handle_set_nopush(L, handle, 0)) moonbr_io_return_errmsg();
         } else {
           handle->flushedleft -= written;
         }
@@ -755,22 +719,14 @@
   }
   handle->finished = 1;
   if (handle->addrfam == AF_INET6 || handle->addrfam == AF_INET) {
-    if (shutdown(handle->fd, SHUT_WR)) {
-      moonbr_io_errmsg();
-      lua_pushnil(L);
-      lua_pushstring(L, errmsg);
-      return 2;
-    }
+    if (shutdown(handle->fd, SHUT_WR)) moonbr_io_return_errmsg();
   } else {
 #ifdef MOONBR_IO_USE_TLS
     if (handle->tls) tls_close(handle->tls);
 #endif
     if (close(handle->fd)) {
-      moonbr_io_errmsg();
       handle->fd = -1;
-      lua_pushnil(L);
-      lua_pushstring(L, errmsg);
-      return 2;
+      moonbr_io_return_errmsg();
     }
     handle->fd = -1;  /* fake EOF on read */
   }
@@ -802,12 +758,10 @@
       handle->closed = 1;
     }
     if (moonbr_io_handle_set_linger(L, handle, -1)) {
-      moonbr_io_errmsg();
+      moonbr_io_prepare_errmsg();
       close(handle->fd);
       handle->fd = -1;
-      lua_pushnil(L);
-      lua_pushstring(L, errmsg);
-      return 2;
+      moonbr_io_return_prepared_errmsg();
     }
   } else {
     handle->closed = 1;
@@ -817,11 +771,8 @@
     if (handle->tls) tls_close(handle->tls);
 #endif
     if (close(handle->fd)) {
-      moonbr_io_errmsg();
       handle->fd = -1;
-      lua_pushnil(L);
-      lua_pushstring(L, errmsg);
-      return 2;
+      moonbr_io_return_errmsg();
     }
     handle->fd = -1;
   }
@@ -881,7 +832,7 @@
   addrlen = sizeof(addr);
   if (getsockname(*fd, &addr, &addrlen)) {
     if (errno != ENOTSOCK) {
-      moonbr_io_errmsg();
+      moonbr_io_prepare_errmsg();
       luaL_error(L, "Unexpected error when examining socket: %s", errmsg);
     }
     handle->issock = 0;
@@ -911,7 +862,7 @@
 #endif
   handle->fd = *fd;  /* required for set_linger call */
   if (moonbr_io_handle_set_linger(L, handle, 0)) {
-    moonbr_io_errmsg();
+    moonbr_io_prepare_errmsg();
     handle->fd = -1;
     luaL_error(L, "Unexpected error while setting SO_LINGER with setsockopt: %s", errmsg);
   }
@@ -927,7 +878,7 @@
     const char *addrstr;
     addrlen = sizeof(addr_in6);
     if (getsockname(*fd, (struct sockaddr *)&addr_in6, &addrlen)) {
-      moonbr_io_errmsg();
+      moonbr_io_prepare_errmsg();
       luaL_error(L, "Could not determine local IP address/port: %s", errmsg);
     }
     if (addrlen > sizeof(addr_in6)) {
@@ -935,7 +886,7 @@
     }
     addrstr = inet_ntop(AF_INET6, addr_in6.sin6_addr.s6_addr, addrstrbuf, sizeof(addrstrbuf));
     if (!addrstr) {
-      moonbr_io_errmsg();
+      moonbr_io_prepare_errmsg();
       luaL_error(L, "Could not format local IP address: %s", errmsg);
     } else {
       lua_pushstring(L, addrstr);
@@ -944,7 +895,7 @@
     lua_pushinteger(L, ntohs(addr_in6.sin6_port));
     lua_setfield(L, -2, "local_tcpport");
     if (getpeername(*fd, (struct sockaddr *)&addr_in6, &addrlen)) {
-      moonbr_io_errmsg();
+      moonbr_io_prepare_errmsg();
       luaL_error(L, "Could not determine remote IP address/port: %s", errmsg);
     }
     if (addrlen > sizeof(addr_in6)) {
@@ -952,7 +903,7 @@
     }
     addrstr = inet_ntop(AF_INET6, addr_in6.sin6_addr.s6_addr, addrstrbuf, sizeof(addrstrbuf));
     if (!addrstr) {
-      moonbr_io_errmsg();
+      moonbr_io_prepare_errmsg();
       luaL_error(L, "Could not format remote IP address: %s", errmsg);
     } else {
       lua_pushstring(L, addrstr);
@@ -966,7 +917,7 @@
     const char *addrstr;
     addrlen = sizeof(addr_in);
     if (getsockname(*fd, (struct sockaddr *)&addr_in, &addrlen)) {
-      moonbr_io_errmsg();
+      moonbr_io_prepare_errmsg();
       luaL_error(L, "Could not determine local IP address/port: %s", errmsg);
     }
     if (addrlen > sizeof(addr_in)) {
@@ -974,7 +925,7 @@
     }
     addrstr = inet_ntop(AF_INET, &addr_in.sin_addr.s_addr, addrstrbuf, sizeof(addrstrbuf));
     if (!addrstr) {
-      moonbr_io_errmsg();
+      moonbr_io_prepare_errmsg();
       luaL_error(L, "Could not format local IP address: %s", errmsg);
     } else {
       lua_pushstring(L, addrstr);
@@ -983,7 +934,7 @@
     lua_pushinteger(L, ntohs(addr_in.sin_port));
     lua_setfield(L, -2, "local_tcpport");
     if (getpeername(*fd, (struct sockaddr *)&addr_in, &addrlen)) {
-      moonbr_io_errmsg();
+      moonbr_io_prepare_errmsg();
       luaL_error(L, "Could not determine remote IP address/port: %s", errmsg);
     }
     if (addrlen > sizeof(addr_in)) {
@@ -991,7 +942,7 @@
     }
     addrstr = inet_ntop(AF_INET, &addr_in.sin_addr.s_addr, addrstrbuf, sizeof(addrstrbuf));
     if (!addrstr) {
-      moonbr_io_errmsg();
+      moonbr_io_prepare_errmsg();
       luaL_error(L, "Could not format remote IP address: %s", errmsg);
     } else {
       lua_pushstring(L, addrstr);
@@ -1054,25 +1005,13 @@
     SOCK_STREAM | SOCK_CLOEXEC | (nonblocking ? SOCK_NONBLOCK : 0),
     0
   );
-  if (sock < 0) {
-    moonbr_io_errmsg();
-    lua_pushnil(L);
-    lua_pushstring(L, errmsg);
-    return 2;
-  }
+  if (sock < 0) moonbr_io_return_errmsg();
   if (connect(sock, (struct sockaddr *)&sockaddr, sizeof(sockaddr))) {
     if (!nonblocking && errno == EINTR) {
-      moonbr_io_errmsg();
+      moonbr_io_prepare_errmsg();
       close(sock);
-      lua_pushnil(L);
-      lua_pushstring(L, errmsg);
-      return 2;
-    } else if (!(nonblocking && (errno == EINPROGRESS || errno == EINTR))) {
-      moonbr_io_errmsg();
-      lua_pushnil(L);
-      lua_pushstring(L, errmsg);
-      return 2;
-    }
+      moonbr_io_return_prepared_errmsg();
+    } else if (!(nonblocking && (errno == EINPROGRESS || errno == EINTR))) moonbr_io_return_errmsg();
   }
   moonbr_io_pushhandle(L, sock);
   return 1;
@@ -1102,7 +1041,7 @@
   if (errcode) {
     freeaddrinfo(res);
     if (errcode == EAI_SYSTEM) {
-      moonbr_io_errmsg();
+      moonbr_io_prepare_errmsg();
       lua_pushnil(L);
       lua_pushfstring(L, "%s: %s", gai_strerror(errcode), errmsg);
     } else {
@@ -1125,26 +1064,17 @@
     addrinfo->ai_protocol
   );
   if (sock < 0) {
-    moonbr_io_errmsg();
+    moonbr_io_prepare_errmsg();
     freeaddrinfo(res);
-    lua_pushnil(L);
-    lua_pushstring(L, errmsg);
-    return 2;
+    moonbr_io_return_prepared_errmsg();
   }
   if (connect(sock, addrinfo->ai_addr, addrinfo->ai_addrlen)) {
     freeaddrinfo(res);
     if (!nonblocking && errno == EINTR) {
-      moonbr_io_errmsg();
+      moonbr_io_prepare_errmsg();
       close(sock);
-      lua_pushnil(L);
-      lua_pushstring(L, errmsg);
-      return 2;
-    } else if (!(nonblocking && (errno == EINPROGRESS || errno == EINTR))) {
-      moonbr_io_errmsg();
-      lua_pushnil(L);
-      lua_pushstring(L, errmsg);
-      return 2;
-    }
+      moonbr_io_return_prepared_errmsg();
+    } else if (!(nonblocking && (errno == EINPROGRESS || errno == EINTR))) moonbr_io_return_errmsg();
   } else {
     freeaddrinfo(res);
   }
@@ -1183,25 +1113,16 @@
     SOCK_STREAM | SOCK_CLOEXEC,
     0
   );
-  if (sock < 0) {
-    moonbr_io_errmsg();
-    lua_pushnil(L);
-    lua_pushstring(L, errmsg);
-    return 2;
-  }
+  if (sock < 0) moonbr_io_return_errmsg();
   if (bind(sock, (struct sockaddr *)&sockaddr, sizeof(sockaddr))) {
-    moonbr_io_errmsg();
+    moonbr_io_prepare_errmsg();
     close(sock);
-    lua_pushnil(L);
-    lua_pushstring(L, errmsg);
-    return 2;
+    moonbr_io_return_prepared_errmsg();
   }
   if (listen(sock, MOONBR_IO_LISTEN_BACKLOG)) {
-    moonbr_io_errmsg();
+    moonbr_io_prepare_errmsg();
     close(sock);
-    lua_pushnil(L);
-    lua_pushstring(L, errmsg);
-    return 2;
+    moonbr_io_return_prepared_errmsg();
   }
   listener->fd = sock;
   listener->addrfam = AF_LOCAL;
@@ -1229,7 +1150,7 @@
   if (errcode) {
     freeaddrinfo(res);
     if (errcode == EAI_SYSTEM) {
-      moonbr_io_errmsg();
+      moonbr_io_prepare_errmsg();
       lua_pushnil(L);
       lua_pushfstring(L, "%s: %s", gai_strerror(errcode), errmsg);
     } else {
@@ -1253,16 +1174,14 @@
     addrinfo->ai_protocol
   );
   if (sock < 0) {
-    moonbr_io_errmsg();
+    moonbr_io_prepare_errmsg();
     freeaddrinfo(res);
-    lua_pushnil(L);
-    lua_pushstring(L, errmsg);
-    return 2;
+    moonbr_io_return_prepared_errmsg();
   }
   {
     static const int reuseval = 1;
     if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &reuseval, sizeof(reuseval))) {
-      moonbr_io_errmsg();
+      moonbr_io_prepare_errmsg();
       freeaddrinfo(res);
       close(sock);
       lua_pushnil(L);
@@ -1271,20 +1190,16 @@
     }
   }
   if (bind(sock, addrinfo->ai_addr, addrinfo->ai_addrlen)) {
-    moonbr_io_errmsg();
+    moonbr_io_prepare_errmsg();
     freeaddrinfo(res);
     close(sock);
-    lua_pushnil(L);
-    lua_pushstring(L, errmsg);
-    return 2;
+    moonbr_io_return_prepared_errmsg();
   }
   freeaddrinfo(res);
   if (listen(sock, MOONBR_IO_LISTEN_BACKLOG)) {
-    moonbr_io_errmsg();
+    moonbr_io_prepare_errmsg();
     close(sock);
-    lua_pushnil(L);
-    lua_pushstring(L, errmsg);
-    return 2;
+    moonbr_io_return_prepared_errmsg();
   }
   listener->fd = sock;
   listener->nonblocking = -1;
@@ -1300,7 +1215,7 @@
     int flags;
     flags = fcntl(listener->fd, F_GETFL, 0);
     if (flags == -1) {
-      moonbr_io_errmsg();
+      moonbr_io_prepare_errmsg();
       close(listener->fd);
       listener->fd = -1;
       luaL_error(L, "Unexpected error in fcntl call: %s", errmsg);
@@ -1308,7 +1223,7 @@
     if (nonblocking) flags |= O_NONBLOCK;
     else flags &= ~O_NONBLOCK;
     if (fcntl(listener->fd, F_SETFL, flags) == -1) {
-      moonbr_io_errmsg();
+      moonbr_io_prepare_errmsg();
       close(listener->fd);
       listener->fd = -1;
       luaL_error(L, "Unexpected error in fcntl call: %s", errmsg);
@@ -1320,7 +1235,7 @@
     fd = accept(listener->fd, NULL, NULL);
     if (fd != -1) {
       if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1) {
-        moonbr_io_errmsg();
+        moonbr_io_prepare_errmsg();
         close(listener->fd);
         listener->fd = -1;
         close(fd);
@@ -1335,12 +1250,7 @@
         lua_pushboolean(L, 0);
         lua_pushliteral(L, "No incoming connection pending");
         return 2;
-      } else if (errno != EINTR) {
-        moonbr_io_errmsg();
-        lua_pushnil(L);
-        lua_pushstring(L, errmsg);
-        return 2;
-      }
+      } else if (errno != EINTR) moonbr_io_return_errmsg();
     } else {
       moonbr_io_pushhandle(L, fd);
       return 1;
@@ -1366,16 +1276,14 @@
   addrlen = sizeof(addr);
   if (getsockname(listener->fd, (struct sockaddr *)&addr, &addrlen)) addrlen = 0;
   if (close(listener->fd)) {
-    moonbr_io_errmsg();
+    moonbr_io_prepare_errmsg();
     listener->fd = -1;
     if (addrlen && addrlen <= sizeof(addr)) {
       if (stat(addr.sun_path, &sb) == 0) {
         if (S_ISSOCK(sb.st_mode)) unlink(addr.sun_path);
       }
     }
-    lua_pushnil(L);
-    lua_pushstring(L, errmsg);
-    return 2;
+    moonbr_io_return_prepared_errmsg();
   }
   listener->fd = -1;
   if (addrlen && addrlen <= sizeof(addr)) {
@@ -1412,13 +1320,13 @@
   lua_setuservalue(L, -2);
   luaL_setmetatable(L, MOONBR_IO_CHILD_MT_REGKEY);
   if (socketpair(PF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, sockin)) {
-    moonbr_io_errmsg();
+    moonbr_io_prepare_errmsg();
     lua_pushnil(L);
     lua_pushfstring(L, "Could not create socket pair: %s", errmsg);
     return 2;
   }
   if (socketpair(PF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, sockout)) {
-    moonbr_io_errmsg();
+    moonbr_io_prepare_errmsg();
     close(sockin[0]);
     close(sockin[1]);
     lua_pushnil(L);
@@ -1426,7 +1334,7 @@
     return 2;
   }
   if (socketpair(PF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, sockerr)) {
-    moonbr_io_errmsg();
+    moonbr_io_prepare_errmsg();
     close(sockin[0]);
     close(sockin[1]);
     close(sockout[0]);
@@ -1437,7 +1345,7 @@
   }
   child->pid = vfork();
   if (child->pid == -1) {
-    moonbr_io_errmsg();
+    moonbr_io_prepare_errmsg();
     close(sockin[0]);
     close(sockin[1]);
     close(sockout[0]);
@@ -1476,7 +1384,7 @@
     close(sockerr[0]);
     while (waitpid(child->pid, &status, 0) == -1) {
       if (errno != EINTR) {
-        moonbr_io_errmsg();
+        moonbr_io_prepare_errmsg();
         luaL_error(L, "Error in waitpid call after unsuccessful exec: %s", errmsg);
       }
     }
@@ -1516,7 +1424,7 @@
     int status;
     while (waitpid(child->pid, &status, 0) == -1) {
       if (errno != EINTR) {
-        moonbr_io_errmsg();
+        moonbr_io_prepare_errmsg();
         luaL_error(L, "Error in waitpid call after error creating socket handles: %s", errmsg);
       }
     }
@@ -1556,12 +1464,12 @@
   if (child->pid) {
     int status;
     if (kill(child->pid, SIGKILL)) {
-      moonbr_io_errmsg();
+      moonbr_io_prepare_errmsg();
       luaL_error(L, "Error in kill call during garbage collection: %s", errmsg);
     }
     while (waitpid(child->pid, &status, 0) == -1) {
       if (errno != EINTR) {
-        moonbr_io_errmsg();
+        moonbr_io_prepare_errmsg();
         luaL_error(L, "Error in waitpid call during garbage collection: %s", errmsg);
       }
     }
@@ -1576,7 +1484,7 @@
   sig = luaL_optinteger(L, 2, SIGTERM);
   if (!child->pid) luaL_error(L, "Attempt to kill an already collected child process");
   if (kill(child->pid, sig)) {
-    moonbr_io_errmsg();
+    moonbr_io_prepare_errmsg();
     luaL_error(L, "Error in kill call: %s", errmsg);
   }
   lua_settop(L, 1);
@@ -1591,7 +1499,7 @@
   if (!child->pid) luaL_error(L, "Attempt to wait for an already collected child process");
   while ((waitedpid = waitpid(child->pid, &status, nonblocking ? WNOHANG : 0)) == -1) {
     if (errno != EINTR) {
-      moonbr_io_errmsg();
+      moonbr_io_prepare_errmsg();
       luaL_error(L, "Error in waitpid call: %s", errmsg);
     }
   }
@@ -1770,7 +1678,7 @@
       lua_pushliteral(L, "Signal received while polling file descriptors");
       return 2;
     } else {
-      moonbr_io_errmsg();
+      moonbr_io_prepare_errmsg();
       return luaL_error(L, "Unexpected error during \"select\" system call: %s", errmsg);
     }
   } else if (status == 0) {