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authorDenis Vlasenko <vda.linux@googlemail.com>2009-04-03 00:07:05 +0000
committerDenis Vlasenko <vda.linux@googlemail.com>2009-04-03 00:07:05 +0000
commitf9f74293465e98f2af117a1821a8fbb97cdbc3ed (patch)
tree5a696966b90b08535a6d1f581357aeb65dfdbeb0 /shell
parent027e3fddb580bf3b397f2392b7e6aeab69adac79 (diff)
downloadbusybox-f9f74293465e98f2af117a1821a8fbb97cdbc3ed.tar.gz
hush: explain parsing context structure
plug leak in setup_redirect on error path function old new delta done_command 84 86 +2 done_word 657 658 +1 done_pipe 105 106 +1 initialize_context 39 38 -1 setup_redirect 219 212 -7 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 3/2 up/down: 4/-8) Total: -4 bytes
Diffstat (limited to 'shell')
-rw-r--r--shell/hush.c53
1 files changed, 32 insertions, 21 deletions
diff --git a/shell/hush.c b/shell/hush.c
index eeec13b3d..d401948aa 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -359,9 +359,13 @@ struct pipe {
/* This holds pointers to the various results of parsing */
struct parse_context {
- struct command *command;
+ /* linked list of pipes */
struct pipe *list_head;
+ /* last pipe (being constructed right now) */
struct pipe *pipe;
+ /* last command in pipe (being constructed right now) */
+ struct command *command;
+ /* last redirect in command->redirects list */
struct redir_struct *pending_redirect;
#if HAS_KEYWORDS
smallint ctx_res_w;
@@ -369,7 +373,15 @@ struct parse_context {
#if ENABLE_HUSH_CASE
smallint ctx_dsemicolon; /* ";;" seen */
#endif
- int old_flag; /* bitmask of FLAG_xxx, for figuring out valid reserved words */
+ /* bitmask of FLAG_xxx, for figuring out valid reserved words */
+ int old_flag;
+ /* group we are enclosed in:
+ * example 1: "{ { false; ..."
+ * example 2: "if true; then { false; ..."
+ * example 3: "if true; then if false; ..."
+ * when we find closing "}" / "fi" / whatever, we move list_head
+ * into stack->command->group and delete ourself.
+ */
struct parse_context *stack;
#endif
};
@@ -3288,37 +3300,36 @@ static int redirect_dup_num(struct in_str *input)
* for file descriptor duplication, e.g., "2>&1".
* Return code is 0 normally, 1 if a syntax error is detected in src.
* Resource errors (in xmalloc) cause the process to exit */
-static int setup_redirect(struct parse_context *ctx, int fd, redir_type style,
- struct in_str *input)
+static int setup_redirect(struct parse_context *ctx,
+ int fd,
+ redir_type style,
+ struct in_str *input)
{
struct command *command = ctx->command;
- struct redir_struct *redir = command->redirects;
- struct redir_struct *last_redir = NULL;
+ struct redir_struct *redir;
+ struct redir_struct **redirp;
+ int dup_num;
+
+ /* Check for a '2>&1' type redirect */
+ dup_num = redirect_dup_num(input);
+ if (dup_num == -2)
+ return 1; /* syntax error */
/* Create a new redir_struct and drop it onto the end of the linked list */
- while (redir) {
- last_redir = redir;
- redir = redir->next;
+ redirp = &command->redirects;
+ while ((redir = *redirp) != NULL) {
+ redirp = &(redir->next);
}
- redir = xzalloc(sizeof(struct redir_struct));
+ *redirp = redir = xzalloc(sizeof(*redir));
/* redir->next = NULL; */
/* redir->rd_filename = NULL; */
- if (last_redir) {
- last_redir->next = redir;
- } else {
- command->redirects = redir;
- }
-
redir->rd_type = style;
redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
- /* Check for a '2>&1' type redirect */
- redir->dup = redirect_dup_num(input);
- if (redir->dup == -2)
- return 1; /* syntax error */
- if (redir->dup != -1) {
+ redir->dup = dup_num;
+ if (dup_num != -1) {
/* Erik had a check here that the file descriptor in question
* is legit; I postpone that to "run time"
* A "-" representation of "close me" shows up as a -3 here */