ash: remove REDIR_SAVEFD2

function                                             old     new   delta
evalcommand                                         1364    1369      +5
redirect                                            1055    1014     -41
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 5/-41)             Total: -36 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/shell/ash.c b/shell/ash.c
index 52fcc7944214c774dcf4dfe85ac6ae9af4db1d9a..1e720aec405be34504aeb64040fd1db7fdc9ecc3 100644 (file)
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -2030,7 +2030,7 @@ struct redirtab;
 struct globals_var {
        struct shparam shellparam;      /* $@ current positional parameters */
        struct redirtab *redirlist;
-       int preverrout_fd;   /* save fd2 before print debug if xflag is set. */
+       int preverrout_fd;   /* stderr fd: usually 2, unless redirect moved it */
        struct var *vartab[VTABSIZE];
        struct var varinit[ARRAY_SIZE(varinit_data)];
 };
@@ -5426,16 +5426,13 @@ is_hidden_fd(struct redirtab *rp, int fd)
  */
 /* flags passed to redirect */
 #define REDIR_PUSH    01        /* save previous values of file descriptors */
-#define REDIR_SAVEFD2 03        /* set preverrout */
 static void
 redirect(union node *redir, int flags)
 {
        struct redirtab *sv;
        int sv_pos;
-       int i;
        int fd;
        int newfd;
-       int copied_fd2 = -1;
 
        if (!redir)
                return;
@@ -5479,37 +5476,38 @@ redirect(union node *redir, int flags)
                         * to the same fd as right side fd in N>&M */
                        int minfd = right_fd < 10 ? 10 : right_fd + 1;
 #if defined(F_DUPFD_CLOEXEC)
-                       i = fcntl(fd, F_DUPFD_CLOEXEC, minfd);
+                       int copy = fcntl(fd, F_DUPFD_CLOEXEC, minfd);
 #else
-                       i = fcntl(fd, F_DUPFD, minfd);
+                       int copy = fcntl(fd, F_DUPFD, minfd);
 #endif
-                       if (i == -1) {
-                               i = errno;
-                               if (i != EBADF) {
+                       if (copy == -1) {
+                               int e = errno;
+                               if (e != EBADF) {
                                        /* Strange error (e.g. "too many files" EMFILE?) */
                                        if (newfd >= 0)
                                                close(newfd);
-                                       errno = i;
+                                       errno = e;
                                        ash_msg_and_raise_perror("%d", fd);
                                        /* NOTREACHED */
                                }
                                /* EBADF: it is not open - good, remember to close it */
  remember_to_close:
-                               i = CLOSED;
+                               copy = CLOSED;
                        } else { /* fd is open, save its copy */
 #if !defined(F_DUPFD_CLOEXEC)
-                               fcntl(i, F_SETFD, FD_CLOEXEC);
+                               fcntl(copy, F_SETFD, FD_CLOEXEC);
 #endif
                                /* "exec fd>&-" should not close fds
                                 * which point to script file(s).
                                 * Force them to be restored afterwards */
                                if (is_hidden_fd(sv, fd))
-                                       i |= COPYFD_RESTORE;
+                                       copy |= COPYFD_RESTORE;
                        }
-                       if (fd == 2)
-                               copied_fd2 = i;
+                       /* if we move stderr, let "set -x" code know */
+                       if (fd == preverrout_fd)
+                               preverrout_fd = copy;
                        sv->two_fd[sv_pos].orig = fd;
-                       sv->two_fd[sv_pos].copy = i;
+                       sv->two_fd[sv_pos].copy = copy;
                        sv_pos++;
                }
                if (newfd < 0) {
@@ -5537,10 +5535,16 @@ redirect(union node *redir, int flags)
                }
 #endif
        } while ((redir = redir->nfile.next) != NULL);
-
        INT_ON;
-       if ((flags & REDIR_SAVEFD2) && copied_fd2 >= 0)
-               preverrout_fd = copied_fd2;
+
+//dash:#define REDIR_SAVEFD2 03        /* set preverrout */
+#define REDIR_SAVEFD2 0
+       // dash has a bug: since REDIR_SAVEFD2=3 and REDIR_PUSH=1, this test
+       // triggers for pure REDIR_PUSH too. Thus, this is done almost always,
+       // not only for calls with flags containing REDIR_SAVEFD2.
+       // We do this unconditionally (see code above).
+       //if ((flags & REDIR_SAVEFD2) && copied_fd2 >= 0)
+       //      preverrout_fd = copied_fd2;
 }
 
 static int
@@ -9655,9 +9659,7 @@ evalcommand(union node *cmd, int flags)
        int spclbltin;
        int status;
        char **nargv;
-       struct builtincmd *bcmd;
        smallint cmd_is_exec;
-       smallint pseudovarflag = 0;
 
        /* First expand the arguments. */
        TRACE(("evalcommand(0x%lx, %d) called\n", (long)cmd, flags));
@@ -9674,21 +9676,24 @@ evalcommand(union node *cmd, int flags)
 
        argc = 0;
        if (cmd->ncmd.args) {
+               struct builtincmd *bcmd;
+               smallint pseudovarflag;
+
                bcmd = find_builtin(cmd->ncmd.args->narg.text);
                pseudovarflag = bcmd && IS_BUILTIN_ASSIGN(bcmd);
-       }
 
-       for (argp = cmd->ncmd.args; argp; argp = argp->narg.next) {
-               struct strlist **spp;
+               for (argp = cmd->ncmd.args; argp; argp = argp->narg.next) {
+                       struct strlist **spp;
 
-               spp = arglist.lastp;
-               if (pseudovarflag && isassignment(argp->narg.text))
-                       expandarg(argp, &arglist, EXP_VARTILDE);
-               else
-                       expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
+                       spp = arglist.lastp;
+                       if (pseudovarflag && isassignment(argp->narg.text))
+                               expandarg(argp, &arglist, EXP_VARTILDE);
+                       else
+                               expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
 
-               for (sp = *spp; sp; sp = sp->next)
-                       argc++;
+                       for (sp = *spp; sp; sp = sp->next)
+                               argc++;
+               }
        }
 
        /* Reserve one extra spot at the front for shellexec. */
@@ -9704,9 +9709,9 @@ evalcommand(union node *cmd, int flags)
        if (iflag && funcnest == 0 && argc > 0)
                lastarg = nargv[-1];
 
-       preverrout_fd = 2;
        expredir(cmd->ncmd.redirect);
        redir_stop = pushredir(cmd->ncmd.redirect);
+       preverrout_fd = 2;
        status = redirectsafe(cmd->ncmd.redirect, REDIR_PUSH | REDIR_SAVEFD2);
 
        path = vpath.var_text;