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hush: preparatory patch for removing extra empty pipes generation

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in parse stage. No real code change here.
This commit is contained in:
Denis Vlasenko 2007-05-05 15:10:52 +00:00
parent 734e5ebc93
commit a6c467f6d1
1 changed files with 88 additions and 78 deletions
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152
shell/hush.c
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@ -125,7 +125,7 @@ static const char *indenter(int i)
#define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0 #define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
#endif #endif
#define SPECIAL_VAR_SYMBOL 03 #define SPECIAL_VAR_SYMBOL 3
#define FLAG_EXIT_FROM_LOOP 1 #define FLAG_EXIT_FROM_LOOP 1
#define FLAG_PARSE_SEMICOLON (1 << 1) /* symbol ';' is special for parser */ #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 */
@ -199,10 +199,10 @@ struct p_context {
struct pipe *list_head; struct pipe *list_head;
struct pipe *pipe; struct pipe *pipe;
struct redir_struct *pending_redirect; struct redir_struct *pending_redirect;
reserved_style w; reserved_style res_w;
int old_flag; /* for figuring out valid reserved words */ int old_flag; /* for figuring out valid reserved words */
struct p_context *stack; 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? */ /* 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_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); static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, const char *end_trigger);
/* setup: */ /* setup: */
static int parse_stream_outer(struct in_str *inp, int flag); static int parse_stream_outer(struct in_str *inp, int parse_flag);
static int parse_string_outer(const char *s, int flag); static int parse_string_outer(const char *s, int parse_flag);
static int parse_file_outer(FILE *f); static int parse_file_outer(FILE *f);
/* job management: */ /* job management: */
static int checkjobs(struct pipe* fg_pipe); static int checkjobs(struct pipe* fg_pipe);
@ -1854,23 +1854,24 @@ static void debug_print_tree(struct pipe *pi, int lvl)
}; };
int pin, prn; int pin, prn;
char **argv;
pin = 0; pin = 0;
while (pi) { while (pi) {
fprintf(stderr, "%*spipe %d r_mode=%s followup=%d %s\n", lvl*2, "", fprintf(stderr, "%*spipe %d r_mode=%s followup=%d %s\n", lvl*2, "",
pin, RES[pi->r_mode], pi->followup, PIPE[pi->followup]); pin, RES[pi->r_mode], pi->followup, PIPE[pi->followup]);
prn = 0; prn = 0;
while (prn < pi->num_progs) { while (prn < pi->num_progs) {
struct child_prog *child = &pi->progs[prn];
char **argv = child->argv;
fprintf(stderr, "%*s prog %d", lvl*2, "", prn); fprintf(stderr, "%*s prog %d", lvl*2, "", prn);
if (pi->progs[prn].group) { if (child->group) {
fprintf(stderr, " group %s: (argv=%p)\n", fprintf(stderr, " group %s: (argv=%p)\n",
(pi->subshell ? "()" : "{}"), (child->subshell ? "()" : "{}"),
pi->progs[prn].argv); argv);
debug_print_tree(pi->progs[prn].group, lvl+1); debug_print_tree(child->group, lvl+1);
prn++; prn++;
continue; continue;
} }
argv = pi->progs[prn].argv;
if (argv) while (*argv) { if (argv) while (*argv) {
fprintf(stderr, " '%s'", *argv); fprintf(stderr, " '%s'", *argv);
argv++; argv++;
@ -1901,7 +1902,7 @@ static int run_list_real(struct pipe *pi)
int flag_rep = 0; int flag_rep = 0;
int save_num_progs; int save_num_progs;
int flag_skip = 1; int flag_skip = 1;
int rcode = 0; /* probaly for gcc only */ int rcode = 0; /* probably for gcc only */
int flag_restore = 0; int flag_restore = 0;
int if_code = 0, next_if_code = 0; /* need double-buffer to handle elif */ int if_code = 0, next_if_code = 0; /* need double-buffer to handle elif */
reserved_style rmode, skip_more_in_this_rmode = RES_XXXX; reserved_style rmode, skip_more_in_this_rmode = RES_XXXX;
@ -1968,17 +1969,15 @@ static int run_list_real(struct pipe *pi)
} }
#endif #endif
for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) { for (; pi; pi = flag_restore ? rpipe : pi->next) {
if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL rmode = pi->r_mode;
|| pi->r_mode == RES_FOR if (rmode == RES_WHILE || rmode == RES_UNTIL || rmode == RES_FOR) {
) {
flag_restore = 0; flag_restore = 0;
if (!rpipe) { if (!rpipe) {
flag_rep = 0; flag_rep = 0;
rpipe = pi; rpipe = pi;
} }
} }
rmode = pi->r_mode;
debug_printf_exec(": rmode=%d if_code=%d next_if_code=%d skip_more=%d\n", 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); rmode, if_code, next_if_code, skip_more_in_this_rmode);
if (rmode == skip_more_in_this_rmode && flag_skip) { 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->child = NULL;
ctx->list_head = new_pipe(); ctx->list_head = new_pipe();
ctx->pipe = ctx->list_head; ctx->pipe = ctx->list_head;
ctx->w = RES_NONE; ctx->res_w = RES_NONE;
ctx->stack = NULL; ctx->stack = NULL;
ctx->old_flag = 0; ctx->old_flag = 0;
done_command(ctx); /* creates the memory for working child */ done_command(ctx); /* creates the memory for working child */
@ -2580,23 +2579,23 @@ static int reserved_word(o_string *dest, struct p_context *ctx)
if (r->flag & FLAG_START) { if (r->flag & FLAG_START) {
struct p_context *new = xmalloc(sizeof(struct p_context)); struct p_context *new = xmalloc(sizeof(struct p_context));
debug_printf("push stack\n"); 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(); syntax();
free(new); free(new);
ctx->w = RES_SNTX; ctx->res_w = RES_SNTX;
b_reset(dest); b_reset(dest);
return 1; return 1;
} }
*new = *ctx; /* physical copy */ *new = *ctx; /* physical copy */
initialize_context(ctx); initialize_context(ctx);
ctx->stack = new; 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(); syntax();
ctx->w = RES_SNTX; ctx->res_w = RES_SNTX;
b_reset(dest); b_reset(dest);
return 1; return 1;
} }
ctx->w = r->code; ctx->res_w = r->code;
ctx->old_flag = r->flag; ctx->old_flag = r->flag;
if (ctx->old_flag & FLAG_END) { if (ctx->old_flag & FLAG_END) {
struct p_context *old; struct p_context *old;
@ -2623,7 +2622,7 @@ static int done_word(o_string *dest, struct p_context *ctx)
glob_t *glob_target; glob_t *glob_target;
int gr, flags = 0; 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) { if (dest->length == 0 && !dest->nonnull) {
debug_printf_parse("done_word return 0: true null, ignored\n"); debug_printf_parse("done_word return 0: true null, ignored\n");
return 0; 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"); debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n");
return 1; return 1;
} }
if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) { if (!child->argv && (ctx->parse_type & FLAG_PARSE_SEMICOLON)) {
debug_printf_parse(": checking %s for reserved-ness\n", dest->data); debug_printf_parse(": checking '%s' for reserved-ness\n", dest->data);
if (reserved_word(dest, ctx)) { if (reserved_word(dest, ctx)) {
debug_printf_parse("done_word return %d\n", (ctx->w == RES_SNTX)); debug_printf_parse("done_word return %d\n", (ctx->res_w == RES_SNTX));
return (ctx->w == RES_SNTX); return (ctx->res_w == RES_SNTX);
} }
} }
glob_target = &child->glob_result; glob_target = &child->glob_result;
if (child->argv) flags |= GLOB_APPEND; if (child->argv)
flags |= GLOB_APPEND;
} }
gr = xglob(dest, flags, glob_target); gr = xglob(dest, flags, glob_target);
if (gr != 0) { if (gr != 0) {
@ -2663,7 +2663,7 @@ static int done_word(o_string *dest, struct p_context *ctx)
} else { } else {
child->argv = glob_target->gl_pathv; child->argv = glob_target->gl_pathv;
} }
if (ctx->w == RES_FOR) { if (ctx->res_w == RES_FOR) {
done_word(dest, ctx); done_word(dest, ctx);
done_pipe(ctx, PIPE_SEQ); 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) static int done_command(struct p_context *ctx)
{ {
/* The child is really already in the pipe structure, so /* The child is really already in the pipe structure, so
* advance the pipe counter and make a new, null child. * 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. */
struct pipe *pi = ctx->pipe; struct pipe *pi = ctx->pipe;
struct child_prog *prog = ctx->child; struct child_prog *child = ctx->child;
if (prog && prog->group == NULL if (child) {
&& prog->argv == NULL if (child->group == NULL
&& prog->redirects == NULL && child->argv == NULL
&& child->redirects == NULL
) { ) {
debug_printf("done_command: skipping null command\n"); debug_printf_parse("done_command: skipping null command\n");
return 0; return 0;
} }
if (prog) {
pi->num_progs++; 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 { } else {
debug_printf("done_command: initializing\n"); debug_printf_parse("done_command: initializing, num_progs=%d\n", pi->num_progs);
} }
/* 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)); pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
child = &pi->progs[pi->num_progs];
prog = pi->progs + pi->num_progs; memset(child, 0, sizeof(*child));
memset(prog, 0, sizeof(*prog)); /*child->redirects = NULL;*/
/*prog->redirects = NULL;*/ /*child->argv = NULL;*/
/*prog->argv = NULL; */ /*child->is_stopped = 0;*/
/*prog->is_stopped = 0;*/ /*child->group = NULL;*/
/*prog->group = NULL;*/ /*child->glob_result.gl_pathv = NULL;*/
/*prog->glob_result.gl_pathv = NULL;*/ child->family = pi;
prog->family = pi; /*child->sp = 0;*/
/*prog->sp = 0;*/ child->type = ctx->parse_type;
ctx->child = prog;
prog->type = ctx->type;
ctx->child = child;
/* but ctx->pipe and ctx->list_head remain unchanged */ /* but ctx->pipe and ctx->list_head remain unchanged */
return 0; return 0;
} }
static int done_pipe(struct p_context *ctx, pipe_style type) static int done_pipe(struct p_context *ctx, pipe_style type)
{ {
struct pipe *new_p; struct pipe *new_p;
debug_printf_parse("done_pipe entered, followup %d\n", type);
done_command(ctx); /* implicit closure of previous command */ done_command(ctx); /* implicit closure of previous command */
debug_printf_parse("done_pipe, type %d\n", type);
ctx->pipe->followup = type; ctx->pipe->followup = type;
ctx->pipe->r_mode = ctx->w; ctx->pipe->r_mode = ctx->res_w;
new_p = new_pipe(); new_p = new_pipe();
ctx->pipe->next = new_p; ctx->pipe->next = new_p;
ctx->pipe = new_p; ctx->pipe = new_p;
ctx->child = NULL; ctx->child = NULL;
// TODO: even just <enter> 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 */ done_command(ctx); /* set up new pipe to accept commands */
debug_printf_parse("done_pipe return 0\n");
return 0; return 0;
} }
@ -3055,7 +3062,7 @@ static int parse_stream(o_string *dest, struct p_context *ctx,
} }
if (m == MAP_IFS_IF_UNQUOTED) { if (m == MAP_IFS_IF_UNQUOTED) {
if (done_word(dest, ctx)) { 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; return 1;
} }
/* If we aren't performing a substitution, treat /* 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)) 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; return 0;
} }
if (m == MAP_IFS_IF_UNQUOTED) if (m == MAP_IFS_IF_UNQUOTED)
@ -3089,7 +3096,7 @@ static int parse_stream(o_string *dest, struct p_context *ctx,
case '\\': case '\\':
if (next == EOF) { if (next == EOF) {
syntax(); syntax();
debug_printf_parse("parse_stream return 1\n"); debug_printf_parse("parse_stream return 1: \\<eof>\n");
return 1; return 1;
} }
b_addqchr(dest, '\\', dest->quote); b_addqchr(dest, '\\', dest->quote);
@ -3111,7 +3118,7 @@ static int parse_stream(o_string *dest, struct p_context *ctx,
} }
if (ch == EOF) { if (ch == EOF) {
syntax(); syntax();
debug_printf_parse("parse_stream return 1\n"); debug_printf_parse("parse_stream return 1: unterminated '\n");
return 1; return 1;
} }
break; 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 * 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, * 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. */ * 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) if (end_trigger)
return -1; return -1;
return 0; return 0;
@ -3220,7 +3227,8 @@ static void update_ifs_map(void)
{ {
/* char *ifs and char map[256] are both globals. */ /* char *ifs and char map[256] are both globals. */
ifs = getenv("IFS"); 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 /* Precompute a list of 'flow through' behavior so it can be treated
* quickly up front. Computation is necessary because of IFS. * quickly up front. Computation is necessary because of IFS.
* Special case handling of IFS == " \t\n" is not implemented. * 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 /* most recursion does not come through here, the exception is
* from builtin_source() */ * 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, // FIXME: '{ true | exit 3; echo $? }' is parsed as a whole,
// as a result $? is replaced by 0, not 3! // as a result $? is replaced by 0, not 3!
// Need to stop & execute stuff at ';', not parse till EOL!
struct p_context ctx; struct p_context ctx;
o_string temp = NULL_O_STRING; o_string temp = NULL_O_STRING;
int rcode; int rcode;
do { do {
ctx.type = flag; ctx.parse_type = parse_flag;
initialize_context(&ctx); initialize_context(&ctx);
update_ifs_map(); update_ifs_map();
if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) if (!(parse_flag & FLAG_PARSE_SEMICOLON) || (parse_flag & FLAG_REPARSING))
mapset(";$&|", MAP_ORDINARY); mapset(";$&|", MAP_ORDINARY);
#if ENABLE_HUSH_INTERACTIVE #if ENABLE_HUSH_INTERACTIVE
inp->promptmode = 1; inp->promptmode = 1;
#endif #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"); rcode = parse_stream(&temp, &ctx, inp, ";\n");
if (rcode != 1 && ctx.old_flag != 0) { if (rcode != 1 && ctx.old_flag != 0) {
syntax(); syntax();
@ -3274,15 +3284,15 @@ static int parse_stream_outer(struct in_str *inp, int flag)
free_pipe_list(ctx.list_head, 0); free_pipe_list(ctx.list_head, 0);
} }
b_free(&temp); 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; 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; struct in_str input;
setup_string_in_str(&input, s); 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) static int parse_file_outer(FILE *f)
@ -3303,7 +3313,7 @@ static void setup_job_control(void)
pid_t shell_pgrp; pid_t shell_pgrp;
saved_task_pgrp = shell_pgrp = getpgrp(); 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); fcntl(interactive_fd, F_SETFD, FD_CLOEXEC);
/* If we were ran as 'hush &', /* If we were ran as 'hush &',
@ -3319,7 +3329,7 @@ static void setup_job_control(void)
set_misc_sighandler(SIG_IGN); set_misc_sighandler(SIG_IGN);
//huh? signal(SIGCHLD, 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); set_fatal_sighandler(sigexit);
/* Put ourselves in our own process group. */ /* Put ourselves in our own process group. */