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hush: fix heredoc expansion of $var and cmd

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function                                             old     new   delta
expand_pseudo_dquoted                                  -     104    +104
setup_heredoc                                        215     275     +60
done_word                                            669     691     +22
parse_stream                                        1899    1902      +3
setup_redirects                                      196     191      -5
free_pipe                                            189     183      -6
expand_variables                                    2349    2229    -120
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 3/3 up/down: 189/-131)           Total: 58 bytes
This commit is contained in:
Denis Vlasenko 2009-04-07 19:56:55 +00:00
parent 25af86f73d
commit 02d6f1ad72
5 changed files with 120 additions and 60 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

159
shell/hush.c
View File

@ -305,7 +305,9 @@ typedef struct o_string {
* (by prepending \ to *, ?, [, \) */ * (by prepending \ to *, ?, [, \) */
smallint o_escape; smallint o_escape;
smallint o_glob; smallint o_glob;
smallint nonnull; /* At least some part of the string was inside '' or "",
* possibly empty one: word"", wo''rd etc. */
smallint o_quoted;
smallint has_empty_slot; smallint has_empty_slot;
smallint o_assignment; /* 0:maybe, 1:yes, 2:no */ smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
} o_string; } o_string;
@ -339,12 +341,14 @@ typedef struct in_str {
struct redir_struct { struct redir_struct {
struct redir_struct *next; struct redir_struct *next;
char *rd_filename; /* filename */ char *rd_filename; /* filename */
int rd_fd; /* file descriptor being redirected */ int rd_fd; /* fd to redirect */
int rd_dup; /* -1, or file descriptor being duplicated */ /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
int rd_dup;
smallint rd_type; /* (enum redir_type) */ smallint rd_type; /* (enum redir_type) */
/* note: for heredocs, rd_filename contains heredoc delimiter, /* note: for heredocs, rd_filename contains heredoc delimiter,
* and subsequently heredoc itself; and rd_dup is * and subsequently heredoc itself; and rd_dup is a bitmask:
* "do we need to trim leading tabs?" bool flag * 1: do we need to trim leading tabs?
* 2: is heredoc quoted (<<'dleim' syntax) ?
*/ */
}; };
typedef enum redir_type { typedef enum redir_type {
@ -355,6 +359,9 @@ typedef enum redir_type {
REDIRECT_HEREDOC = 4, REDIRECT_HEREDOC = 4,
REDIRECT_IO = 5, REDIRECT_IO = 5,
REDIRECT_HEREDOC2 = 6, /* REDIRECT_HEREDOC after heredoc is loaded */ REDIRECT_HEREDOC2 = 6, /* REDIRECT_HEREDOC after heredoc is loaded */
REDIRFD_CLOSE = -3,
HEREDOC_SKIPTABS = 1,
HEREDOC_QUOTED = 2,
} redir_type; } redir_type;
@ -1328,7 +1335,7 @@ static void setup_string_in_str(struct in_str *i, const char *s)
static void o_reset(o_string *o) static void o_reset(o_string *o)
{ {
o->length = 0; o->length = 0;
o->nonnull = 0; o->o_quoted = 0;
if (o->data) if (o->data)
o->data[0] = '\0'; o->data[0] = '\0';
} }
@ -1677,6 +1684,39 @@ static int expand_on_ifs(o_string *output, int n, const char *str)
return n; return n;
} }
/* Helper to expand $((...)) and heredoc body. These act as if
* they are in double quotes, with the exception that they are not :).
* Just the rules are similar: "expand only $var and `cmd`"
*
* Returns malloced string.
* As an optimization, we return NULL if expansion is not needed.
*/
static char *expand_pseudo_dquoted(const char *str)
{
char *exp_str;
struct in_str input;
o_string dest = NULL_O_STRING;
if (strchr(str, '$') == NULL
#if ENABLE_HUSH_TICK
&& strchr(str, '`') == NULL
#endif
) {
return NULL;
}
/* We need to expand. Example:
* echo $(($a + `echo 1`)) $((1 + $((2)) ))
*/
setup_string_in_str(&input, str);
parse_stream_dquoted(NULL, &dest, &input, EOF);
//bb_error_msg("'%s' -> '%s'", str, dest.data);
exp_str = expand_string_to_string(dest.data);
//bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
o_free_unsafe(&dest);
return exp_str;
}
/* Expand all variable references in given string, adding words to list[] /* Expand all variable references in given string, adding words to list[]
* at n, n+1,... positions. Return updated n (so that list[n] is next one * at n, n+1,... positions. Return updated n (so that list[n] is next one
* to be filled). This routine is extremely tricky: has to deal with * to be filled). This routine is extremely tricky: has to deal with
@ -1809,26 +1849,7 @@ static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
*p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */ *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch); debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
/* Optional: skip expansion if expr is simple ("a + 3", "i++" etc) */ exp_str = expand_pseudo_dquoted(arg);
exp_str = NULL;
if (strchr(arg, '$') != NULL
#if ENABLE_HUSH_TICK
|| strchr(arg, '`') != NULL
#endif
) {
/* We need to expand. Example:
* echo $(($a + `echo 1`)) $((1 + $((2)) ))
*/
struct in_str input;
o_string dest = NULL_O_STRING;
setup_string_in_str(&input, arg);
parse_stream_dquoted(NULL, &dest, &input, EOF);
//bb_error_msg("'%s' -> '%s'", arg, dest.data);
exp_str = expand_string_to_string(dest.data);
//bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
o_free_unsafe(&dest);
}
hooks.lookupvar = get_local_var_value; hooks.lookupvar = get_local_var_value;
hooks.setvar = arith_set_local_var; hooks.setvar = arith_set_local_var;
hooks.endofname = endofname; hooks.endofname = endofname;
@ -2195,16 +2216,26 @@ static void clean_up_after_re_execute(void)
#endif /* !BB_MMU */ #endif /* !BB_MMU */
static void setup_heredoc(int fd, const char *heredoc) static void setup_heredoc(struct redir_struct *redir)
{ {
struct fd_pair pair; struct fd_pair pair;
pid_t pid; pid_t pid;
int len, written; int len, written;
/* the _body_ of heredoc (misleading field name) */
const char *heredoc = redir->rd_filename;
char *expanded;
expanded = NULL;
if (!(redir->rd_dup & HEREDOC_QUOTED)) {
expanded = expand_pseudo_dquoted(heredoc);
if (expanded)
heredoc = expanded;
}
len = strlen(heredoc);
xpiped_pair(pair); xpiped_pair(pair);
xmove_fd(pair.rd, fd); xmove_fd(pair.rd, redir->rd_fd);
len = strlen(heredoc);
/* Try writing without forking. Newer kernels have /* Try writing without forking. Newer kernels have
* dynamically growing pipes. Must use non-blocking write! */ * dynamically growing pipes. Must use non-blocking write! */
ndelay_on(pair.wr); ndelay_on(pair.wr);
@ -2237,7 +2268,7 @@ static void setup_heredoc(int fd, const char *heredoc)
if (pid != 0) if (pid != 0)
_exit(0); _exit(0);
/* grandchild */ /* grandchild */
close(fd); /* read side of the pipe */ close(redir->rd_fd); /* read side of the pipe */
#if BB_MMU #if BB_MMU
full_write(pair.wr, heredoc, len); /* may loop or block */ full_write(pair.wr, heredoc, len); /* may loop or block */
_exit(0); _exit(0);
@ -2252,6 +2283,7 @@ static void setup_heredoc(int fd, const char *heredoc)
enable_restore_tty_pgrp_on_exit(); enable_restore_tty_pgrp_on_exit();
clean_up_after_re_execute(); clean_up_after_re_execute();
close(pair.wr); close(pair.wr);
free(expanded);
wait(NULL); /* wait till child has died */ wait(NULL); /* wait till child has died */
} }
@ -2272,7 +2304,7 @@ static int setup_redirects(struct command *prog, int squirrel[])
* of the heredoc */ * of the heredoc */
debug_printf_parse("set heredoc '%s'\n", debug_printf_parse("set heredoc '%s'\n",
redir->rd_filename); redir->rd_filename);
setup_heredoc(redir->rd_fd, redir->rd_filename); setup_heredoc(redir);
continue; continue;
} }
@ -2302,11 +2334,11 @@ static int setup_redirects(struct command *prog, int squirrel[])
if (squirrel && redir->rd_fd < 3) { if (squirrel && redir->rd_fd < 3) {
squirrel[redir->rd_fd] = dup(redir->rd_fd); squirrel[redir->rd_fd] = dup(redir->rd_fd);
} }
if (openfd == -3) { if (openfd == REDIRFD_CLOSE) {
/* "-" means "close me" and we use -3 for that */ /* "n>-" means "close me" */
close(redir->rd_fd); close(redir->rd_fd);
} else { } else {
dup2(openfd, redir->rd_fd); xdup2(openfd, redir->rd_fd);
if (redir->rd_dup == -1) if (redir->rd_dup == -1)
close(openfd); close(openfd);
} }
@ -2350,14 +2382,16 @@ static void free_pipe(struct pipe *pi, int indent)
debug_printf_clean("%s command %d:\n", indenter(indent), i); debug_printf_clean("%s command %d:\n", indenter(indent), i);
if (command->argv) { if (command->argv) {
for (a = 0, p = command->argv; *p; a++, p++) { for (a = 0, p = command->argv; *p; a++, p++) {
debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p); debug_printf_clean("%s argv[%d] = %s\n",
indenter(indent), a, *p);
} }
free_strings(command->argv); free_strings(command->argv);
command->argv = NULL; command->argv = NULL;
} }
/* not "else if": on syntax error, we may have both! */ /* not "else if": on syntax error, we may have both! */
if (command->group) { if (command->group) {
debug_printf_clean("%s begin group (grp_type:%d)\n", indenter(indent), command->grp_type); debug_printf_clean("%s begin group (grp_type:%d)\n",
indenter(indent), command->grp_type);
free_pipe_list(command->group, indent+3); free_pipe_list(command->group, indent+3);
debug_printf_clean("%s end group\n", indenter(indent)); debug_printf_clean("%s end group\n", indenter(indent));
command->group = NULL; command->group = NULL;
@ -2367,17 +2401,15 @@ static void free_pipe(struct pipe *pi, int indent)
command->group_as_string = NULL; command->group_as_string = NULL;
#endif #endif
for (r = command->redirects; r; r = rnext) { for (r = command->redirects; r; r = rnext) {
debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->rd_type].descrip); debug_printf_clean("%s redirect %d%s", indenter(indent),
if (r->rd_dup == -1) { r->fd, redir_table[r->rd_type].descrip);
/* guard against the case >$FOO, where foo is unset or blank */ /* guard against the case >$FOO, where foo is unset or blank */
if (r->rd_filename) { if (r->rd_filename) {
debug_printf_clean(" %s\n", r->rd_filename); debug_printf_clean(" fname:'%s'\n", r->rd_filename);
free(r->rd_filename); free(r->rd_filename);
r->rd_filename = NULL; r->rd_filename = NULL;
}
} else {
debug_printf_clean("&%d\n", r->rd_dup);
} }
debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
rnext = r->next; rnext = r->next;
free(r); free(r);
} }
@ -3791,7 +3823,7 @@ static int done_word(o_string *word, struct parse_context *ctx)
struct command *command = ctx->command; struct command *command = ctx->command;
debug_printf_parse("done_word entered: '%s' %p\n", word->data, command); debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
if (word->length == 0 && word->nonnull == 0) { if (word->length == 0 && word->o_quoted == 0) {
debug_printf_parse("done_word return 0: true null, ignored\n"); debug_printf_parse("done_word return 0: true null, ignored\n");
return 0; return 0;
} }
@ -3821,6 +3853,11 @@ static int done_word(o_string *word, struct parse_context *ctx)
* the expansion would result in one word." * the expansion would result in one word."
*/ */
ctx->pending_redirect->rd_filename = xstrdup(word->data); ctx->pending_redirect->rd_filename = xstrdup(word->data);
if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC
&& word->o_quoted
) {
ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
}
word->o_assignment = NOT_ASSIGNMENT; word->o_assignment = NOT_ASSIGNMENT;
debug_printf_parse("word stored in rd_filename: '%s'\n", word->data); debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
} else { } else {
@ -3862,7 +3899,7 @@ static int done_word(o_string *word, struct parse_context *ctx)
} }
} }
#endif #endif
if (word->nonnull /* word had "xx" or 'xx' at least as part of it. */ if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
/* optimization: and if it's ("" or '') or ($v... or `cmd`...): */ /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
&& (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL) && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
/* (otherwise it's known to be not empty and is already safe) */ /* (otherwise it's known to be not empty and is already safe) */
@ -3914,7 +3951,7 @@ static int done_word(o_string *word, struct parse_context *ctx)
/* Peek ahead in the input to find out if we have a "&n" construct, /* Peek ahead in the input to find out if we have a "&n" construct,
* as in "2>&1", that represents duplicating a file descriptor. * as in "2>&1", that represents duplicating a file descriptor.
* Return: -3 if >&- "close fd" construct is seen, * Return: REDIRFD_CLOSE (-3) if >&- "close fd" construct is seen,
* -2 (syntax error), -1 if no & was seen, or the number found. * -2 (syntax error), -1 if no & was seen, or the number found.
*/ */
#if BB_MMU #if BB_MMU
@ -3935,7 +3972,7 @@ static int redirect_dup_num(o_string *as_string, struct in_str *input)
if (ch == '-') { if (ch == '-') {
ch = i_getch(input); ch = i_getch(input);
nommu_addchr(as_string, ch); nommu_addchr(as_string, ch);
return -3; /* "-" represents "close me" */ return REDIRFD_CLOSE;
} }
d = 0; d = 0;
ok = 0; ok = 0;
@ -3974,7 +4011,7 @@ static int parse_redirect(struct parse_context *ctx,
return 1; /* syntax error */ return 1; /* syntax error */
} else { } else {
int ch = i_peek(input); int ch = i_peek(input);
dup_num = (ch == '-'); dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
if (dup_num) { /* <<-... */ if (dup_num) { /* <<-... */
ch = i_getch(input); ch = i_getch(input);
nommu_addchr(&ctx->as_string, ch); nommu_addchr(&ctx->as_string, ch);
@ -4011,14 +4048,16 @@ static int parse_redirect(struct parse_context *ctx,
redir->rd_type = style; redir->rd_type = style;
redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd; redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
debug_printf_parse("redirect type %d %s\n", redir->rd_fd, redir_table[style].descrip); debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
redir_table[style].descrip);
redir->rd_dup = dup_num; redir->rd_dup = dup_num;
if (style != REDIRECT_HEREDOC && dup_num != -1) { if (style != REDIRECT_HEREDOC && dup_num != -1) {
/* Erik had a check here that the file descriptor in question /* Erik had a check here that the file descriptor in question
* is legit; I postpone that to "run time" * is legit; I postpone that to "run time"
* A "-" representation of "close me" shows up as a -3 here */ * A "-" representation of "close me" shows up as a -3 here */
debug_printf_parse("duplicating redirect '%d>&%d'\n", redir->rd_fd, redir->rd_dup); debug_printf_parse("duplicating redirect '%d>&%d'\n",
redir->rd_fd, redir->rd_dup);
} else { } else {
/* Set ctx->pending_redirect, so we know what to do at the /* Set ctx->pending_redirect, so we know what to do at the
* end of the next parsed word. */ * end of the next parsed word. */
@ -4127,7 +4166,7 @@ static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_
redir->rd_type = REDIRECT_HEREDOC2; redir->rd_type = REDIRECT_HEREDOC2;
/* redir->dup is (ab)used to indicate <<- */ /* redir->dup is (ab)used to indicate <<- */
p = fetch_till_str(&ctx->as_string, input, p = fetch_till_str(&ctx->as_string, input,
redir->rd_filename, redir->rd_dup); redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
if (!p) if (!p)
return 1; /* unexpected EOF */ return 1; /* unexpected EOF */
free(redir->rd_filename); free(redir->rd_filename);
@ -4264,7 +4303,7 @@ static int parse_group(o_string *dest, struct parse_context *ctx,
#endif #endif
if (command->argv /* word [word](... */ if (command->argv /* word [word](... */
|| dest->length /* word(... */ || dest->length /* word(... */
|| dest->nonnull /* ""(... */ || dest->o_quoted /* ""(... */
) { ) {
syntax(NULL); syntax(NULL);
debug_printf_parse("parse_group return 1: " debug_printf_parse("parse_group return 1: "
@ -4634,7 +4673,7 @@ static int parse_stream_dquoted(o_string *as_string,
if (ch != EOF) if (ch != EOF)
nommu_addchr(as_string, ch); nommu_addchr(as_string, ch);
if (ch == dquote_end) { /* may be only '"' or EOF */ if (ch == dquote_end) { /* may be only '"' or EOF */
dest->nonnull = 1; dest->o_quoted = 1;
if (dest->o_assignment == NOT_ASSIGNMENT) if (dest->o_assignment == NOT_ASSIGNMENT)
dest->o_escape ^= 1; dest->o_escape ^= 1;
debug_printf_parse("parse_stream_dquoted return 0\n"); debug_printf_parse("parse_stream_dquoted return 0\n");
@ -4923,7 +4962,7 @@ static struct pipe *parse_stream(char **pstring,
} }
break; break;
case '\'': case '\'':
dest.nonnull = 1; dest.o_quoted = 1;
while (1) { while (1) {
ch = i_getch(input); ch = i_getch(input);
if (ch == EOF) { if (ch == EOF) {
@ -4940,7 +4979,7 @@ static struct pipe *parse_stream(char **pstring,
} }
break; break;
case '"': case '"':
dest.nonnull = 1; dest.o_quoted = 1;
is_in_dquote ^= 1; /* invert */ is_in_dquote ^= 1; /* invert */
if (dest.o_assignment == NOT_ASSIGNMENT) if (dest.o_assignment == NOT_ASSIGNMENT)
dest.o_escape ^= 1; dest.o_escape ^= 1;
@ -5068,14 +5107,14 @@ static struct pipe *parse_stream(char **pstring,
if (ctx.ctx_res_w == RES_MATCH if (ctx.ctx_res_w == RES_MATCH
&& ctx.command->argv == NULL /* not (word|(... */ && ctx.command->argv == NULL /* not (word|(... */
&& dest.length == 0 /* not word(... */ && dest.length == 0 /* not word(... */
&& dest.nonnull == 0 /* not ""(... */ && dest.o_quoted == 0 /* not ""(... */
) { ) {
continue; continue;
} }
#endif #endif
#if ENABLE_HUSH_FUNCTIONS #if ENABLE_HUSH_FUNCTIONS
if (dest.length != 0 /* not just () but word() */ if (dest.length != 0 /* not just () but word() */
&& dest.nonnull == 0 /* not a"b"c() */ && dest.o_quoted == 0 /* not a"b"c() */
&& ctx.command->argv == NULL /* it's the first word */ && ctx.command->argv == NULL /* it's the first word */
//TODO: "func ( ) {...}" - note spaces - is valid format too in bash //TODO: "func ( ) {...}" - note spaces - is valid format too in bash
&& i_peek(input) == ')' && i_peek(input) == ')'

1
shell/hush_test/hush-misc/heredoc2.right
View File

@ -1,6 +1,7 @@
exit EOF-f exit EOF-f
" "
echo 1 echo 1
echo Hello World
moo moo
EOF-f EOF-f
EOF-f f EOF-f f

1
shell/hush_test/hush-misc/heredoc2.tests
View File

@ -3,6 +3,7 @@ f=1
exit EOF-f exit EOF-f
" "
echo $f echo $f
echo `echo Hello World`
moo moo
EOF-f EOF-f
EOF-f f EOF-f f

8
shell/hush_test/hush-misc/heredoc3.right Normal file
View File

@ -0,0 +1,8 @@
exit EOF-f
"
echo $f
echo `echo Hello World`
moo
EOF-f
EOF-f f
EOF-f

11
shell/hush_test/hush-misc/heredoc3.tests Executable file
View File

@ -0,0 +1,11 @@
f=1
cat <<- EOF-f""
exit EOF-f
"
echo $f
echo `echo Hello World`
moo
EOF-f
EOF-f f
EOF-f
EOF-f