diff options
Diffstat (limited to 'shell/hush.c')
| -rw-r--r-- | shell/hush.c | 74 |
1 files changed, 55 insertions, 19 deletions
diff --git a/shell/hush.c b/shell/hush.c index a055ec1..a56b2e6 100644 --- a/shell/hush.c +++ b/shell/hush.c @@ -330,7 +330,7 @@ struct redir_struct { /* note: for heredocs, rd_filename contains heredoc delimiter, * and subsequently heredoc itself; and rd_dup is a bitmask: * 1: do we need to trim leading tabs? - * 2: is heredoc quoted (<<'dleim' syntax) ? + * 2: is heredoc quoted (<<'delim' syntax) ? */ }; typedef enum redir_type { @@ -357,25 +357,42 @@ struct command { int assignment_cnt; /* how many argv[i] are assignments? */ smallint is_stopped; /* is the command currently running? */ smallint grp_type; /* GRP_xxx */ +#define GRP_NORMAL 0 +#define GRP_SUBSHELL 1 +#if ENABLE_HUSH_FUNCTIONS +# define GRP_FUNCTION 2 +#endif struct pipe *group; /* if non-NULL, this "command" is { list }, * ( list ), or a compound statement */ #if !BB_MMU char *group_as_string; #endif +#if ENABLE_HUSH_FUNCTIONS + struct function *child_func; +/* This field is used to prevent a bug here: + * while...do f1() {a;}; f1; f1 {b;}; f1; done + * When we execute "f1() {a;}" cmd, we create new function and clear + * cmd->group, cmd->group_as_string, cmd->argv[0]. + * when we execute "f1 {b;}", we notice that f1 exists, + * and that it's "parent cmd" struct is still "alive", + * we put those fields back into cmd->xxx + * (struct function has ->parent_cmd ptr to facilitate that). + * When we loop back, we can execute "f1() {a;}" again and set f1 correctly. + * Without this trick, loop would execute a;b;b;b;... + * instead of correct sequence a;b;a;b;... + * When command is freed, it severs the link + * (sets ->child_func->parent_cmd to NULL). + */ +#endif char **argv; /* command name and arguments */ - struct redir_struct *redirects; /* I/O redirections */ -}; /* argv vector may contain variable references (^Cvar^C, ^C0^C etc) * and on execution these are substituted with their values. * Substitution can make _several_ words out of one argv[n]! * Example: argv[0]=='.^C*^C.' here: echo .$*. * References of the form ^C`cmd arg^C are `cmd arg` substitutions. */ -#define GRP_NORMAL 0 -#define GRP_SUBSHELL 1 -#if ENABLE_HUSH_FUNCTIONS -# define GRP_FUNCTION 2 -#endif + struct redir_struct *redirects; /* I/O redirections */ +}; struct pipe { struct pipe *next; @@ -456,6 +473,7 @@ enum { struct function { struct function *next; char *name; + struct command *parent_cmd; struct pipe *body; #if !BB_MMU char *body_as_string; @@ -743,7 +761,6 @@ static void syntax_error_unexpected_ch(unsigned lineno, char ch) msg[0] = ch; msg[1] = '\0'; die_if_script(lineno, "syntax error: unexpected %s", msg); - xfunc_die(); } #if HUSH_DEBUG < 2 @@ -2573,6 +2590,14 @@ static void free_pipe(struct pipe *pi, int indent) debug_printf_clean("%s end group\n", indenter(indent)); command->group = NULL; } + /* else is crucial here. + * If group != NULL, child_func is meaningless */ +#if ENABLE_HUSH_FUNCTIONS + else if (command->child_func) { + debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func); + command->child_func->parent_cmd = NULL; + } +#endif #if !BB_MMU free(command->group_as_string); command->group_as_string = NULL; @@ -3173,9 +3198,24 @@ static int run_pipe(struct pipe *pi) while ((funcp = *funcpp) != NULL) { if (strcmp(funcp->name, command->argv[0]) == 0) { - debug_printf_exec("replacing function '%s'\n", funcp->name); - free(funcp->name); - free_pipe_list(funcp->body, /* indent: */ 0); + struct command *cmd = funcp->parent_cmd; + + debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd); + if (!cmd) { + debug_printf_exec("freeing & replacing function '%s'\n", funcp->name); + free(funcp->name); + free_pipe_list(funcp->body, /* indent: */ 0); +#if !BB_MMU + free(funcp->body_as_string); +#endif + } else { + debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name); + cmd->argv[0] = funcp->name; + cmd->group = funcp->body; +#if !BB_MMU + cmd->group_as_string = funcp->body_as_string; +#endif + } goto skip; } funcpp = &funcp->next; @@ -3192,13 +3232,9 @@ static int run_pipe(struct pipe *pi) #endif command->group = NULL; command->argv[0] = NULL; - free_strings(command->argv); - command->argv = NULL; - /* note: if we are in a loop, future "executions" - * of func def will see it as null command since - * command->group == NULL and command->argv == NULL */ -//this isn't exactly right: while...do f1() {a;}; f1; f1 {b;}; done -//second loop will execute b! + debug_printf_exec("cmd %p has child func at %p\n", command, funcp); + funcp->parent_cmd = command; + command->child_func = funcp; return EXIT_SUCCESS; } |