From a6c467f6d134f1fb906806f4cf3b6ca401b6a616 Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Sat, 5 May 2007 15:10:52 +0000 Subject: [PATCH] hush: preparatory patch for removing extra empty pipes generation in parse stage. No real code change here. --- shell/hush.c | 170 +++++++++++++++++++++++++++------------------------ 1 file changed, 90 insertions(+), 80 deletions(-) diff --git a/shell/hush.c b/shell/hush.c index 78531e864..eb6f37f15 100644 --- a/shell/hush.c +++ b/shell/hush.c @@ -125,10 +125,10 @@ static const char *indenter(int i) #define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0 #endif -#define SPECIAL_VAR_SYMBOL 03 -#define FLAG_EXIT_FROM_LOOP 1 +#define SPECIAL_VAR_SYMBOL 3 +#define FLAG_EXIT_FROM_LOOP 1 #define FLAG_PARSE_SEMICOLON (1 << 1) /* symbol ';' is special for parser */ -#define FLAG_REPARSING (1 << 2) /* >=2nd pass */ +#define FLAG_REPARSING (1 << 2) /* >= 2nd pass */ typedef enum { REDIRECT_INPUT = 1, @@ -199,10 +199,10 @@ struct p_context { struct pipe *list_head; struct pipe *pipe; struct redir_struct *pending_redirect; - reserved_style w; - int old_flag; /* for figuring out valid reserved words */ + reserved_style res_w; + int old_flag; /* for figuring out valid reserved words */ struct p_context *stack; - int type; /* define type of parser : ";$" common or special symbol */ + int parse_type; /* define type of parser : ";$" common or special symbol */ /* How about quoting status? */ }; @@ -410,8 +410,8 @@ static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *i static int parse_string(o_string *dest, struct p_context *ctx, const char *src); static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, const char *end_trigger); /* setup: */ -static int parse_stream_outer(struct in_str *inp, int flag); -static int parse_string_outer(const char *s, int flag); +static int parse_stream_outer(struct in_str *inp, int parse_flag); +static int parse_string_outer(const char *s, int parse_flag); static int parse_file_outer(FILE *f); /* job management: */ static int checkjobs(struct pipe* fg_pipe); @@ -1854,23 +1854,24 @@ static void debug_print_tree(struct pipe *pi, int lvl) }; int pin, prn; - char **argv; pin = 0; while (pi) { fprintf(stderr, "%*spipe %d r_mode=%s followup=%d %s\n", lvl*2, "", pin, RES[pi->r_mode], pi->followup, PIPE[pi->followup]); prn = 0; while (prn < pi->num_progs) { + struct child_prog *child = &pi->progs[prn]; + char **argv = child->argv; + fprintf(stderr, "%*s prog %d", lvl*2, "", prn); - if (pi->progs[prn].group) { + if (child->group) { fprintf(stderr, " group %s: (argv=%p)\n", - (pi->subshell ? "()" : "{}"), - pi->progs[prn].argv); - debug_print_tree(pi->progs[prn].group, lvl+1); + (child->subshell ? "()" : "{}"), + argv); + debug_print_tree(child->group, lvl+1); prn++; continue; } - argv = pi->progs[prn].argv; if (argv) while (*argv) { fprintf(stderr, " '%s'", *argv); argv++; @@ -1901,7 +1902,7 @@ static int run_list_real(struct pipe *pi) int flag_rep = 0; int save_num_progs; int flag_skip = 1; - int rcode = 0; /* probaly for gcc only */ + int rcode = 0; /* probably for gcc only */ int flag_restore = 0; int if_code = 0, next_if_code = 0; /* need double-buffer to handle elif */ reserved_style rmode, skip_more_in_this_rmode = RES_XXXX; @@ -1968,17 +1969,15 @@ static int run_list_real(struct pipe *pi) } #endif - for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) { - if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL - || pi->r_mode == RES_FOR - ) { + for (; pi; pi = flag_restore ? rpipe : pi->next) { + rmode = pi->r_mode; + if (rmode == RES_WHILE || rmode == RES_UNTIL || rmode == RES_FOR) { flag_restore = 0; if (!rpipe) { flag_rep = 0; rpipe = pi; } } - rmode = pi->r_mode; debug_printf_exec(": rmode=%d if_code=%d next_if_code=%d skip_more=%d\n", rmode, if_code, next_if_code, skip_more_in_this_rmode); if (rmode == skip_more_in_this_rmode && flag_skip) { @@ -2535,7 +2534,7 @@ static void initialize_context(struct p_context *ctx) ctx->child = NULL; ctx->list_head = new_pipe(); ctx->pipe = ctx->list_head; - ctx->w = RES_NONE; + ctx->res_w = RES_NONE; ctx->stack = NULL; ctx->old_flag = 0; done_command(ctx); /* creates the memory for working child */ @@ -2574,29 +2573,29 @@ static int reserved_word(o_string *dest, struct p_context *ctx) enum { NRES = sizeof(reserved_list)/sizeof(reserved_list[0]) }; const struct reserved_combo *r; - for (r = reserved_list; r < reserved_list+NRES; r++) { + for (r = reserved_list; r < reserved_list + NRES; r++) { if (strcmp(dest->data, r->literal) == 0) { debug_printf("found reserved word %s, code %d\n", r->literal, r->code); if (r->flag & FLAG_START) { struct p_context *new = xmalloc(sizeof(struct p_context)); debug_printf("push stack\n"); - if (ctx->w == RES_IN || ctx->w == RES_FOR) { + if (ctx->res_w == RES_IN || ctx->res_w == RES_FOR) { syntax(); free(new); - ctx->w = RES_SNTX; + ctx->res_w = RES_SNTX; b_reset(dest); return 1; } *new = *ctx; /* physical copy */ initialize_context(ctx); ctx->stack = new; - } else if (ctx->w == RES_NONE || !(ctx->old_flag & (1 << r->code))) { + } else if (ctx->res_w == RES_NONE || !(ctx->old_flag & (1 << r->code))) { syntax(); - ctx->w = RES_SNTX; + ctx->res_w = RES_SNTX; b_reset(dest); return 1; } - ctx->w = r->code; + ctx->res_w = r->code; ctx->old_flag = r->flag; if (ctx->old_flag & FLAG_END) { struct p_context *old; @@ -2623,7 +2622,7 @@ static int done_word(o_string *dest, struct p_context *ctx) glob_t *glob_target; int gr, flags = 0; - debug_printf_parse("done_word: '%s' %p\n", dest->data, child); + debug_printf_parse("done_word entered: '%s' %p\n", dest->data, child); if (dest->length == 0 && !dest->nonnull) { debug_printf_parse("done_word return 0: true null, ignored\n"); return 0; @@ -2636,15 +2635,16 @@ static int done_word(o_string *dest, struct p_context *ctx) debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n"); return 1; } - if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) { - debug_printf_parse(": checking %s for reserved-ness\n", dest->data); + if (!child->argv && (ctx->parse_type & FLAG_PARSE_SEMICOLON)) { + debug_printf_parse(": checking '%s' for reserved-ness\n", dest->data); if (reserved_word(dest, ctx)) { - debug_printf_parse("done_word return %d\n", (ctx->w == RES_SNTX)); - return (ctx->w == RES_SNTX); + debug_printf_parse("done_word return %d\n", (ctx->res_w == RES_SNTX)); + return (ctx->res_w == RES_SNTX); } } glob_target = &child->glob_result; - if (child->argv) flags |= GLOB_APPEND; + if (child->argv) + flags |= GLOB_APPEND; } gr = xglob(dest, flags, glob_target); if (gr != 0) { @@ -2663,7 +2663,7 @@ static int done_word(o_string *dest, struct p_context *ctx) } else { child->argv = glob_target->gl_pathv; } - if (ctx->w == RES_FOR) { + if (ctx->res_w == RES_FOR) { done_word(dest, ctx); done_pipe(ctx, PIPE_SEQ); } @@ -2676,56 +2676,63 @@ static int done_word(o_string *dest, struct p_context *ctx) static int done_command(struct p_context *ctx) { /* The child is really already in the pipe structure, so - * advance the pipe counter and make a new, null child. - * Only real trickiness here is that the uncommitted - * child structure, to which ctx->child points, is not - * counted in pi->num_progs. */ + * advance the pipe counter and make a new, null child. */ struct pipe *pi = ctx->pipe; - struct child_prog *prog = ctx->child; + struct child_prog *child = ctx->child; - if (prog && prog->group == NULL - && prog->argv == NULL - && prog->redirects == NULL - ) { - debug_printf("done_command: skipping null command\n"); - return 0; - } - if (prog) { + if (child) { + if (child->group == NULL + && child->argv == NULL + && child->redirects == NULL + ) { + debug_printf_parse("done_command: skipping null command\n"); + return 0; + } pi->num_progs++; - debug_printf("done_command: num_progs incremented to %d\n", pi->num_progs); + debug_printf_parse("done_command: ++num_progs=%d\n", pi->num_progs); } else { - debug_printf("done_command: initializing\n"); + debug_printf_parse("done_command: initializing, num_progs=%d\n", pi->num_progs); } - pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1)); - - prog = pi->progs + pi->num_progs; - memset(prog, 0, sizeof(*prog)); - /*prog->redirects = NULL;*/ - /*prog->argv = NULL; */ - /*prog->is_stopped = 0;*/ - /*prog->group = NULL;*/ - /*prog->glob_result.gl_pathv = NULL;*/ - prog->family = pi; - /*prog->sp = 0;*/ - ctx->child = prog; - prog->type = ctx->type; + /* Only real trickiness here is that the uncommitted + * child structure is not counted in pi->num_progs. */ + pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1)); + child = &pi->progs[pi->num_progs]; + + memset(child, 0, sizeof(*child)); + /*child->redirects = NULL;*/ + /*child->argv = NULL;*/ + /*child->is_stopped = 0;*/ + /*child->group = NULL;*/ + /*child->glob_result.gl_pathv = NULL;*/ + child->family = pi; + /*child->sp = 0;*/ + child->type = ctx->parse_type; + + ctx->child = child; /* but ctx->pipe and ctx->list_head remain unchanged */ + return 0; } static int done_pipe(struct p_context *ctx, pipe_style type) { struct pipe *new_p; + + debug_printf_parse("done_pipe entered, followup %d\n", type); done_command(ctx); /* implicit closure of previous command */ - debug_printf_parse("done_pipe, type %d\n", type); ctx->pipe->followup = type; - ctx->pipe->r_mode = ctx->w; + ctx->pipe->r_mode = ctx->res_w; new_p = new_pipe(); ctx->pipe->next = new_p; ctx->pipe = new_p; ctx->child = NULL; +// TODO: even just on command line basically generates +// tree of three NOPs (!). +// Can we detect that previous done_command have seen "skipping null command" +// condition and NOT create new pipe here? done_command(ctx); /* set up new pipe to accept commands */ + debug_printf_parse("done_pipe return 0\n"); return 0; } @@ -3055,7 +3062,7 @@ static int parse_stream(o_string *dest, struct p_context *ctx, } if (m == MAP_IFS_IF_UNQUOTED) { if (done_word(dest, ctx)) { - debug_printf_parse("parse_stream return 1\n"); + debug_printf_parse("parse_stream return 1: done_word!=0\n"); return 1; } /* If we aren't performing a substitution, treat @@ -3066,9 +3073,9 @@ static int parse_stream(o_string *dest, struct p_context *ctx, } } if ((end_trigger && strchr(end_trigger, ch)) - && !dest->quote && ctx->w == RES_NONE + && !dest->quote && ctx->res_w == RES_NONE ) { - debug_printf_parse("parse_stream return 0\n"); + debug_printf_parse("parse_stream return 0: end_trigger char found\n"); return 0; } if (m == MAP_IFS_IF_UNQUOTED) @@ -3089,7 +3096,7 @@ static int parse_stream(o_string *dest, struct p_context *ctx, case '\\': if (next == EOF) { syntax(); - debug_printf_parse("parse_stream return 1\n"); + debug_printf_parse("parse_stream return 1: \\\n"); return 1; } b_addqchr(dest, '\\', dest->quote); @@ -3111,7 +3118,7 @@ static int parse_stream(o_string *dest, struct p_context *ctx, } if (ch == EOF) { syntax(); - debug_printf_parse("parse_stream return 1\n"); + debug_printf_parse("parse_stream return 1: unterminated '\n"); return 1; } break; @@ -3204,7 +3211,7 @@ static int parse_stream(o_string *dest, struct p_context *ctx, * that is, we were really supposed to get end_trigger, and never got * one before the EOF. Can't use the standard "syntax error" return code, * so that parse_stream_outer can distinguish the EOF and exit smoothly. */ - debug_printf_parse("parse_stream return -%d\n", end_trigger != NULL); + debug_printf_parse("parse_stream return %d\n", -(end_trigger != NULL)); if (end_trigger) return -1; return 0; @@ -3220,7 +3227,8 @@ static void update_ifs_map(void) { /* char *ifs and char map[256] are both globals. */ ifs = getenv("IFS"); - if (ifs == NULL) ifs = " \t\n"; + if (ifs == NULL) + ifs = " \t\n"; /* Precompute a list of 'flow through' behavior so it can be treated * quickly up front. Computation is necessary because of IFS. * Special case handling of IFS == " \t\n" is not implemented. @@ -3235,24 +3243,26 @@ static void update_ifs_map(void) /* most recursion does not come through here, the exception is * from builtin_source() */ -static int parse_stream_outer(struct in_str *inp, int flag) +static int parse_stream_outer(struct in_str *inp, int parse_flag) { // FIXME: '{ true | exit 3; echo $? }' is parsed as a whole, // as a result $? is replaced by 0, not 3! -// Need to stop & execute stuff at ';', not parse till EOL! struct p_context ctx; o_string temp = NULL_O_STRING; int rcode; do { - ctx.type = flag; + ctx.parse_type = parse_flag; initialize_context(&ctx); update_ifs_map(); - if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) + if (!(parse_flag & FLAG_PARSE_SEMICOLON) || (parse_flag & FLAG_REPARSING)) mapset(";$&|", MAP_ORDINARY); #if ENABLE_HUSH_INTERACTIVE inp->promptmode = 1; #endif + /* We will stop & execute after each ';' or '\n'. + * Example: "sleep 9999; echo TEST" + ctrl-C: + * TEST should be printed */ rcode = parse_stream(&temp, &ctx, inp, ";\n"); if (rcode != 1 && ctx.old_flag != 0) { syntax(); @@ -3274,15 +3284,15 @@ static int parse_stream_outer(struct in_str *inp, int flag) free_pipe_list(ctx.list_head, 0); } b_free(&temp); - } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP)); /* loop on syntax errors, return on EOF */ + } while (rcode != -1 && !(parse_flag & FLAG_EXIT_FROM_LOOP)); /* loop on syntax errors, return on EOF */ return 0; } -static int parse_string_outer(const char *s, int flag) +static int parse_string_outer(const char *s, int parse_flag) { struct in_str input; setup_string_in_str(&input, s); - return parse_stream_outer(&input, flag); + return parse_stream_outer(&input, parse_flag); } static int parse_file_outer(FILE *f) @@ -3303,7 +3313,7 @@ static void setup_job_control(void) pid_t shell_pgrp; saved_task_pgrp = shell_pgrp = getpgrp(); - debug_printf("saved_task_pgrp=%d\n", saved_task_pgrp); + debug_printf_jobs("saved_task_pgrp=%d\n", saved_task_pgrp); fcntl(interactive_fd, F_SETFD, FD_CLOEXEC); /* If we were ran as 'hush &', @@ -3319,7 +3329,7 @@ static void setup_job_control(void) set_misc_sighandler(SIG_IGN); //huh? signal(SIGCHLD, SIG_IGN); - /* We _must_ restore tty pgrp fatal signals */ + /* We _must_ restore tty pgrp on fatal signals */ set_fatal_sighandler(sigexit); /* Put ourselves in our own process group. */ -- 2.25.1