From 17f02e79f407ff2311255981c191a1bf8b3a7ae0 Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Mon, 14 Jul 2008 04:32:29 +0000 Subject: [PATCH] hush: add case statement support. It is incomplete and disabled for now. costs ~300 bytes when enabled. --- shell/hush.c | 192 +++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 147 insertions(+), 45 deletions(-) diff --git a/shell/hush.c b/shell/hush.c index aab53c336..47e53f8c1 100644 --- a/shell/hush.c +++ b/shell/hush.c @@ -73,6 +73,9 @@ #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */ +// TEMP +#define ENABLE_HUSH_CASE 0 + #if !BB_MMU && ENABLE_HUSH_TICK //#undef ENABLE_HUSH_TICK @@ -262,22 +265,29 @@ typedef enum { typedef enum { RES_NONE = 0, #if ENABLE_HUSH_IF - RES_IF = 1, - RES_THEN = 2, - RES_ELIF = 3, - RES_ELSE = 4, - RES_FI = 5, + RES_IF , + RES_THEN , + RES_ELIF , + RES_ELSE , + RES_FI , #endif #if ENABLE_HUSH_LOOPS - RES_FOR = 6, - RES_WHILE = 7, - RES_UNTIL = 8, - RES_DO = 9, - RES_DONE = 10, - RES_IN = 11, -#endif - RES_XXXX = 12, - RES_SNTX = 13 + RES_FOR , + RES_WHILE , + RES_UNTIL , + RES_DO , + RES_DONE , + RES_IN , +#endif +#if ENABLE_HUSH_CASE + RES_CASE , + /* two pseudo-keywords support contrived "case" syntax: */ + RES_MATCH , /* "word)" */ + RES_CASEI , /* "this command is inside CASE" */ + RES_ESAC , +#endif + RES_XXXX , + RES_SNTX } reserved_style; /* This holds pointers to the various results of parsing */ @@ -289,6 +299,9 @@ struct p_context { #if HAS_KEYWORDS smallint ctx_res_w; smallint ctx_inverted; /* "! cmd | cmd" */ +#if ENABLE_HUSH_CASE + smallint ctx_dsemicolon; /* ";;" seen */ +#endif int old_flag; /* bitmask of FLAG_xxx, for figuring out valid reserved words */ struct p_context *stack; #endif @@ -350,7 +363,7 @@ struct variable { typedef struct { char *data; - int length; + int length; /* position where data is appended */ int maxlen; /* Misnomer! it's not "quoting", it's "protection against globbing"! * (by prepending \ to *, ?, [ and to \ too) */ @@ -1954,6 +1967,12 @@ static void debug_print_tree(struct pipe *pi, int lvl) [RES_DO ] = "DO" , [RES_DONE ] = "DONE" , [RES_IN ] = "IN" , +#endif +#if ENABLE_HUSH_CASE + [RES_CASE ] = "CASE" , + [RES_MATCH] = "MATCH", + [RES_CASEI] = "CASEI", + [RES_ESAC ] = "ESAC" , #endif [RES_XXXX ] = "XXXX" , [RES_SNTX ] = "SNTX" , @@ -2002,6 +2021,9 @@ static int run_list(struct pipe *pi) char **for_lcur = NULL; char **for_list = NULL; int flag_rep = 0; +#endif +#if ENABLE_HUSH_CASE + char *case_word = NULL; #endif int flag_skip = 1; int rcode = 0; /* probably for gcc only */ @@ -2019,17 +2041,20 @@ static int run_list(struct pipe *pi) #if ENABLE_HUSH_LOOPS /* check syntax for "for" */ for (rpipe = pi; rpipe; rpipe = rpipe->next) { - if ((rpipe->res_word == RES_IN || rpipe->res_word == RES_FOR) - && (rpipe->next == NULL) - ) { - syntax("malformed for"); /* no IN or no commands after IN */ + if (rpipe->res_word != RES_FOR && rpipe->res_word != RES_IN) + continue; + /* current word is FOR or IN (BOLD in comments below) */ + if (rpipe->next == NULL) { + syntax("malformed for"); debug_printf_exec("run_list lvl %d return 1\n", run_list_level); return 1; } - if (/* Extra statement after IN: "for a in a b; echo Hi; do ...; done" ? */ - (rpipe->res_word == RES_IN && rpipe->next->res_word == RES_IN && rpipe->next->progs[0].argv != NULL) - /* FOR not followed by IN or DO ("for var; do..." case)? */ - || (rpipe->res_word == RES_FOR && (rpipe->next->res_word != RES_IN && rpipe->next->res_word != RES_DO)) + /* "FOR v; do ..." and "for v IN a b; do..." are ok */ + if (rpipe->next->res_word == RES_DO) + continue; + /* next word is not "do". It must be "in" then ("FOR v in ...") */ + if (rpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */ + || rpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */ ) { syntax("malformed for"); debug_printf_exec("run_list lvl %d return 1\n", run_list_level); @@ -2136,8 +2161,8 @@ static int run_list(struct pipe *pi) /* create list of variable values */ debug_print_strings("for_list made from", vals); for_list = expand_strvec_to_strvec(vals); - debug_print_strings("for_list", for_list); for_lcur = for_list; + debug_print_strings("for_list", for_list); for_varname = pi->progs->argv[0]; pi->progs->argv[0] = NULL; flag_rep = 1; @@ -2169,6 +2194,26 @@ static int run_list(struct pipe *pi) } } #endif +#if ENABLE_HUSH_CASE + if (rword == RES_CASE) { + case_word = pi->progs->argv[0]; + continue; + } + if (rword == RES_MATCH) { + if (case_word) { + next_if_code = strcmp(case_word, pi->progs->argv[0]); + if (next_if_code == 0) + case_word = NULL; + continue; + } + break; + } + if (rword == RES_CASEI) { + if (next_if_code != 0) + continue; + } +#endif + if (pi->num_progs == 0) continue; debug_printf_exec(": run_pipe with %d members\n", pi->num_progs); @@ -2193,8 +2238,7 @@ static int run_list(struct pipe *pi) rcode = checkjobs_and_fg_shell(pi); } else #endif - { - /* this one just waits for completion */ + { /* this one just waits for completion */ rcode = checkjobs(pi); } debug_printf_exec(": checkjobs returned %d\n", rcode); @@ -2217,12 +2261,13 @@ static int run_list(struct pipe *pi) skip_more_for_this_rword = rword; } checkjobs(NULL); - } + } /* for (pi) */ #if ENABLE_HUSH_JOB if (ctrl_z_flag) { /* ctrl-Z forked somewhere in the past, we are the child, * and now we completed running the list. Exit. */ +//TODO: _exit? exit(rcode); } ret: @@ -2820,6 +2865,10 @@ static int reserved_word(const o_string *word, struct p_context *ctx) FLAG_DO = (1 << RES_DO ), FLAG_DONE = (1 << RES_DONE ), FLAG_IN = (1 << RES_IN ), +#endif +#if ENABLE_HUSH_CASE + FLAG_MATCH = (1 << RES_MATCH), + FLAG_ESAC = (1 << RES_ESAC ), #endif FLAG_START = (1 << RES_XXXX ), }; @@ -2843,16 +2892,30 @@ static int reserved_word(const o_string *word, struct p_context *ctx) { "until", RES_UNTIL, FLAG_DO | FLAG_START }, { "in", RES_IN, FLAG_DO }, { "do", RES_DO, FLAG_DONE }, - { "done", RES_DONE, FLAG_END } + { "done", RES_DONE, FLAG_END }, +#endif +#if ENABLE_HUSH_CASE + { "case", RES_CASE, FLAG_MATCH | FLAG_START }, + { "esac", RES_ESAC, FLAG_END }, #endif }; - +#if ENABLE_HUSH_CASE + static const struct reserved_combo reserved_match = { + "" /* "match" */, RES_MATCH, FLAG_MATCH | FLAG_ESAC + }; +#endif const struct reserved_combo *r; for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) { if (strcmp(word->data, r->literal) != 0) continue; debug_printf("found reserved word %s, res %d\n", r->literal, r->res); +#if ENABLE_HUSH_CASE + if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE) + /* "case word IN ..." - IN part starts first match part */ + r = &reserved_match; + else +#endif if (r->flag == 0) { /* '!' */ if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */ syntax(NULL); @@ -2864,13 +2927,6 @@ static int reserved_word(const o_string *word, struct p_context *ctx) if (r->flag & FLAG_START) { struct p_context *new; debug_printf("push stack\n"); -#if ENABLE_HUSH_LOOPS - if (ctx->ctx_res_w == RES_IN || ctx->ctx_res_w == RES_FOR) { - syntax("malformed for"); /* example: 'for if' */ - ctx->ctx_res_w = RES_SNTX; - return 1; - } -#endif new = xmalloc(sizeof(*new)); *new = *ctx; /* physical copy */ initialize_context(ctx); @@ -2924,12 +2980,20 @@ static int done_word(o_string *word, struct p_context *ctx) word->o_assignment = NOT_ASSIGNMENT; debug_printf("word stored in rd_filename: '%s'\n", word->data); } else { - if (child->group) { /* TODO: example how to trigger? */ - syntax(NULL); - debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n"); - return 1; - } +// if (child->group) { /* TODO: example how to trigger? */ +// syntax(NULL); +// debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n"); +// return 1; +// } #if HAS_KEYWORDS +#if ENABLE_HUSH_CASE + if (ctx->ctx_dsemicolon) { + /* already done when ctx_dsemicolon was set to 1 */ + /* ctx->ctx_res_w = RES_MATCH; */ + ctx->ctx_dsemicolon = 0; + } else +#endif + if (!child->argv /* if it's the first word... */ #if ENABLE_HUSH_LOOPS && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */ @@ -2983,6 +3047,12 @@ static int done_word(o_string *word, struct p_context *ctx) //TODO: check that child->argv[0] is a valid variable name! done_pipe(ctx, PIPE_SEQ); } +#endif +#if ENABLE_HUSH_CASE + /* Force CASE to have just one word */ + if (ctx->ctx_res_w == RES_CASE) { + done_pipe(ctx, PIPE_SEQ); + } #endif debug_printf_parse("done_word return 0\n"); return 0; @@ -3055,6 +3125,10 @@ static void done_pipe(struct p_context *ctx, pipe_style type) if (ctx->ctx_res_w == RES_FOR || ctx->ctx_res_w == RES_IN) ctx->ctx_res_w = RES_NONE; +#endif +#if ENABLE_HUSH_CASE + if (ctx->ctx_res_w == RES_MATCH) + ctx->ctx_res_w = RES_CASEI; #endif /* Create the memory for child, roughly: * ctx->pipe->progs = new struct child_prog; @@ -3458,10 +3532,9 @@ static int handle_dollar(o_string *dest, struct in_str *input) } /* Scan input, call done_word() whenever full IFS delimited word was seen. - * call done_pipe if '\n' was seen (and end_trigger != NULL) - * Return if (non-quoted) char in end_trigger was seen; or on parse error. */ -/* Return code is 0 if end_trigger char is met, - * -1 on EOF (but if end_trigger == NULL then return 0) + * Call done_pipe if '\n' was seen (and end_trigger != NULL). + * Return code is 0 if end_trigger char is met, + * -1 on EOF (but if end_trigger == NULL then return 0), * 1 for syntax error */ static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input, const char *end_trigger) @@ -3664,8 +3737,26 @@ static int parse_stream(o_string *dest, struct p_context *ctx, setup_redirect(ctx, redir_fd, redir_style, input); break; case ';': +#if ENABLE_HUSH_CASE + case_semi: +#endif done_word(dest, ctx); done_pipe(ctx, PIPE_SEQ); +#if ENABLE_HUSH_CASE + /* Eat multiple semicolons, detect + * whether it means something special */ + while (1) { + ch = i_peek(input); + if (ch != ';') + break; + i_getch(input); + if (ctx->ctx_res_w == RES_CASEI) { + ctx->ctx_dsemicolon = 1; + ctx->ctx_res_w = RES_MATCH; + break; + } + } +#endif break; case '&': done_word(dest, ctx); @@ -3689,6 +3780,13 @@ static int parse_stream(o_string *dest, struct p_context *ctx, } break; case '(': +#if ENABLE_HUSH_CASE + if (dest->length == 0 // && argv[0] == NULL + && ctx->ctx_res_w == RES_MATCH + ) { + continue; + } +#endif case '{': if (parse_group(dest, ctx, input, ch) != 0) { debug_printf_parse("parse_stream return 1: parse_group returned non-0\n"); @@ -3696,6 +3794,10 @@ static int parse_stream(o_string *dest, struct p_context *ctx, } break; case ')': +#if ENABLE_HUSH_CASE + if (ctx->ctx_res_w == RES_MATCH) + goto case_semi; +#endif case '}': /* proper use of this character is caught by end_trigger */ syntax("unexpected } or )"); -- 2.25.1