[Findutils-patches] [PATCH 2/2] Avoid mixing declarations and statements.

[James Youngman]

* lib/buildcmd.c (bc_do_exec): Declare variables at the top of the
relevant block, in order to avoid mixing declarations and
statements.
* xargs/xargs.c (main): Likewise.

* NEWS: Mention the fix for bug #22708 in the correct section.
---
 ChangeLog      |   46 ++++++++++++++++++++++++++++++++++++++++++++++
 NEWS           |   17 ++++++++++++-----
 lib/buildcmd.c |   21 ++++++++++++---------
 xargs/xargs.c  |    3 ++-
 4 files changed, 72 insertions(+), 15 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 06e3d71..5b91447 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,49 @@
+2009-04-12  James Youngman  <address@hidden>
+
+       * NEWS: Mention the fix for bug #22708 in the correct section.
+
+       Avoid mixing declarations and statements.
+       * lib/buildcmd.c (bc_do_exec): Declare variables at the top of the
+       relevant block, in order to avoid mixing declarations and
+       statements.
+       * xargs/xargs.c (main): Likewise.
+
+2009-04-12  Leslie Polzer  <address@hidden>
+
+        Merge Leslie Polzer's ARG_MAX enhancements to xargs which were
+        produced as part of the Google Summer of Code 2007.
+        These changes fix Savannah bug #22708.
+        * find/pred.c (launch): The struct buildcmd_control* argument is
+        no longer const.
+        * find/defs.h: Likewise
+        * lib/buildcmd.c (bc_do_insert): The struct buildcmd_control*
+        argument is no longer const.
+        (bc_push_arg): Likewise.
+        (cb_exec_noop): Likewise.
+        (get_stringv_len): New function; measures the length of
+        a NULL-terminated argv sequence.
+        (bc_do_exec): Rename from do_exec, and make global.  Modify the
+        function to react to exec failing with E2BIG by trying again
+        with fewer arguments.
+        * xargs/xargs.1: Mention that xargs automatically adopts to the
+        situation where exec fails with E2BIG.
+        * xargs/xargs.c: (parent): New variable, the PID of the parent
+        process.
+        (main): initialise the variable 'parent'.   Don't fail immediately
+        due to lack of space when the environment is large.  Call
+        xargs_do_exec via bc_do_exec.
+        (xargs_do_exec): The struct buildcmd_control* argument is no
+        longer const.   When exec fails in the child, communicate the
+        errno value back to the parent through a pipe which is
+        close-on-exec; this allows us to accurately determine the cause of
+        the failure and also to distinguish exec failures from all
+        possible exit codes in the child.
+        (wait_for_proc): If the utility cannot be found or cannot be run,
+        we now find out about this by reading an errno value from the
+        pipe, so this means that exit codes 126 and 127 in the child no
+        longer have a special interpretation.
+        * NEWS: mention these changes.
+
 2009-03-07  James Youngman  <address@hidden>
 
        Update the code to better reflect the semantics of digest_mode().
diff --git a/NEWS b/NEWS
index fe9b426..5fe3ebe 100644
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,18 @@ GNU findutils NEWS - User visible changes.     -*- outline -*- 
(allout)
 
 * Major changes in release 4.5.5-git, YYYY-MM-DD
 
+xargs now handles the case where the system's actual exec limits are
+smaller than the value of ARG_MAX at compile time.  Very few platforms
+normally have this property, but it is possible to configure some Unix
+systems this way.
+
+** Bug Fixes
+
+#22708: Exit status 126 and 127 from the utility invoked from xargs
+now makes xargs return 123, meaning that exit status values 126 and
+127 now unambigously mean that the utility could not be run or could
+not be found, respectively.
+
 * Major changes in release 4.5.4, 2009-03-10
 
 ** Performance changes
@@ -37,11 +49,6 @@ declarations to follow statements.
 #24342: -inum predicate shoud use dirent.d_ino instead of stat.st_ino
 (this is a performance bug).
 
-#22708: Exit status 126 and 127 from the utility invoked from xargs
-now makes xargs return 123, meaning that exit status values 126 and
-127 now unambigously mean that the utility could not be run or could
-not be found, respectively.
-
 ** Translations
 
 Updated translations for Bulgarian, German, Irish, Hungarian,
diff --git a/lib/buildcmd.c b/lib/buildcmd.c
index 5fcced1..8cf8ff1 100644
--- a/lib/buildcmd.c
+++ b/lib/buildcmd.c
@@ -184,21 +184,25 @@ void
 bc_do_exec(struct buildcmd_control *ctl,
           struct buildcmd_state *state)
 {
+    int argc_orig;
+    char** argv_orig;
+    char** initial_args;
+    int i, pos, done, argc_current;
+
     bc_push_arg (ctl, state,
             (char *) NULL, 0,
             NULL, 0,
             false); /* Null terminate the arg list.  */
    
     /* save original argv data so we can free the memory later */
-    int argc_orig = state->cmd_argc;
-    char** argv_orig = state->cmd_argv;
+    argc_orig = state->cmd_argc;
+    argv_orig = state->cmd_argv;
 
     if ((ctl->exec_callback)(ctl, state))
         goto fin;
 
     /* got E2BIG, adjust arguments */
-    char** initial_args = xmalloc(ctl->initial_argc * sizeof(char*));
-    int i;
+    initial_args = xmalloc(ctl->initial_argc * sizeof(char*));
     for (i=0; i<ctl->initial_argc; ++i)
         initial_args[i] = argv_orig[i];
 
@@ -206,15 +210,14 @@ bc_do_exec(struct buildcmd_control *ctl,
     state->cmd_argv += ctl->initial_argc;
 
 
-    int pos;
-    int done = 0; /* number of argv elements we have relayed successfully */
-
-    int argc_current = state->cmd_argc;
+    done = 0; /* number of argv elements we have relayed successfully */
+    argc_current = state->cmd_argc;
 
     pos = -1; /* array offset from the right end */
 
     for (;;)
     {
+        int r;
         int divider = argc_current+pos;
         char* swapped_out = state->cmd_argv[divider];
         state->cmd_argv[divider] = NULL;
@@ -230,7 +233,7 @@ bc_do_exec(struct buildcmd_control *ctl,
             state->cmd_argv[i] = initial_args[i];
 
         ++state->cmd_argc; /* include trailing NULL */
-        int r = (ctl->exec_callback)(ctl, state);
+        r = (ctl->exec_callback)(ctl, state);
         state->cmd_argv += ctl->initial_argc;
         state->cmd_argc -= ctl->initial_argc;
         --state->cmd_argc; /* exclude trailing NULL again */
diff --git a/xargs/xargs.c b/xargs/xargs.c
index 0f41a37..46c3cf0 100644
--- a/xargs/xargs.c
+++ b/xargs/xargs.c
@@ -437,9 +437,10 @@ main (int argc, char **argv)
        * environment list shall not exceed {ARG_MAX}-2048 bytes.  It also
        * specifies that it shall be at least LINE_MAX.
        */
+      long val;
       assert(bc_ctl.arg_max <= (ARG_MAX-2048));
 #ifdef _SC_ARG_MAX  
-      long val = sysconf(_SC_ARG_MAX);
+      val = sysconf(_SC_ARG_MAX);
       if (val > 0)
        {
          /* Note that val can in fact be greater than ARG_MAX
-- 
1.5.6.5