[RFC PATCH v4 25/28] cli: hush_2021: Add upstream commits up to 6th February 2022.

Francis Laniel
2022-06-16T22:37:18Z

This commit adds the following hush busybox upstream commits:
21afddefd258 ("hush: fix "error: invalid preprocessing directive ##"")
e53c7dbafc78 ("hush: fix set -n to act immediately, not just after run_list()
")
574b9c446da1 ("hush: fix var_LINENO3.tests failure")
49bcf9f40cff ("hush: speed up ${x//\*/|} too")
53b2fdcdba4c ("*: add NOINLINEs where code noticeably shrinks")
7c3e96d4b3d4 ("shell: use more compact SHELL_ASH / HUSH config defines. no code changes")
62f1eed1e191 ("hush: in a comment, document what -i might be doing")
aaf3d5ba74c5 ("shell: tweak --help")
db5546ca1018 ("libbb: code shrink: introduce and use [_]exit_SUCCESS()")
931c55f9e2b4 ("libbb: invert the meaning of SETUP_ENV_NO_CHDIR -> SETUP_ENV_CHDIR")
12566e7f9b5e ("ash,hush: fix handling of SIGINT while waiting for interactive input")
987be932ed3c ("*: slap on a few ALIGN_PTR where appropriate")

Signed-off-by: Francis Laniel <francis.laniel@amarulasolutions.com>
---
common/cli_hush_upstream.c | 157 +++++++++++++++++++++++++++----------
1 file changed, 117 insertions(+), 40 deletions(-)

diff --git a/common/cli_hush_upstream.c b/common/cli_hush_upstream.c
index 9127183ed7..3158642418 100644
--- a/common/cli_hush_upstream.c
+++ b/common/cli_hush_upstream.c
@@ -339,7 +339,7 @@
* therefore we don't show them either.
*/
//usage:#define hush_trivial_usage
-//usage: "[-enxl] [-c 'SCRIPT' [ARG0 ARGS] | FILE [ARGS] | -s [ARGS]]"
+//usage: "[-enxl] [-c 'SCRIPT' [ARG0 ARGS] | FILE ARGS | -s ARGS]"
//usage:#define hush_full_usage "\n\n"
//usage: "Unix shell interpreter"

@@ -374,7 +374,7 @@
# define F_DUPFD_CLOEXEC F_DUPFD
#endif

-#if ENABLE_FEATURE_SH_EMBEDDED_SCRIPTS && !(ENABLE_ASH || ENABLE_SH_IS_ASH || ENABLE_BASH_IS_ASH)
+#if ENABLE_FEATURE_SH_EMBEDDED_SCRIPTS && !ENABLE_SHELL_ASH
# include "embedded_scripts.h"
#else
# define NUM_SCRIPTS 0
@@ -574,7 +574,7 @@ enum {
#define NULL_O_STRING { NULL }

#ifndef debug_printf_parse
-static const char *const assignment_flag[] = {
+static const char *const assignment_flag[] ALIGN_PTR = {
"MAYBE_ASSIGNMENT",
"DEFINITELY_ASSIGNMENT",
"NOT_ASSIGNMENT",
@@ -958,6 +958,7 @@ struct globals {
#if ENABLE_HUSH_INTERACTIVE
smallint promptmode; /* 0: PS1, 1: PS2 */
#endif
+ /* set by signal handler if SIGINT is received _and_ its trap is not set */
smallint flag_SIGINT;
#ifndef __U_BOOT__
#if ENABLE_HUSH_LOOPS
@@ -2027,6 +2028,9 @@ enum {
static void record_pending_signo(int sig)
{
sigaddset(&G.pending_set, sig);
+#if ENABLE_FEATURE_EDITING
+ bb_got_signal = sig; /* for read_line_input: "we got a signal" */
+#endif
#if ENABLE_HUSH_FAST
if (sig == SIGCHLD) {
G.count_SIGCHLD++;
@@ -2792,30 +2796,53 @@ static void get_user_input(struct in_str *i)
for (;;) {
reinit_unicode_for_hush();
G.flag_SIGINT = 0;
- /* buglet: SIGINT will not make new prompt to appear _at once_,
- * only after <Enter>. (^C works immediately) */
- r = read_line_input(G.line_input_state, prompt_str,
+
+ bb_got_signal = 0;
+ if (!sigisemptyset(&G.pending_set)) {
+ /* Whoops, already got a signal, do not call read_line_input */
+ bb_got_signal = r = -1;
+ } else {
+ /* For shell, LI_INTERRUPTIBLE is set:
+ * read_line_input will abort on either
+ * getting EINTR in poll(), or if it sees bb_got_signal != 0
+ * (IOW: if signal arrives before poll() is reached).
+ * Interactive testcases:
+ * (while kill -INT $$; do sleep 1; done) &
+ * #^^^ prints ^C, prints prompt, repeats
+ * trap 'echo I' int; (while kill -INT $$; do sleep 1; done) &
+ * #^^^ prints ^C, prints "I", prints prompt, repeats
+ * trap 'echo T' term; (while kill $$; do sleep 1; done) &
+ * #^^^ prints "T", prints prompt, repeats
+ * #(bash 5.0.17 exits after first "T", looks like a bug)
+ */
+ r = read_line_input(G.line_input_state, prompt_str,
G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1
- );
- /* read_line_input intercepts ^C, "convert" it to SIGINT */
- if (r == 0) {
- raise(SIGINT);
+ );
+ /* read_line_input intercepts ^C, "convert" it to SIGINT */
+ if (r == 0)
+ raise(SIGINT);
+ }
+ /* bash prints ^C (before running a trap, if any)
+ * both on keyboard ^C and on real SIGINT (non-kbd generated).
+ */
+ if (sigismember(&G.pending_set, SIGINT)) {
+ write(STDOUT_FILENO, "^C\n", 3);
+ G.last_exitcode = 128 | SIGINT;
}
check_and_run_traps();
- if (r != 0 && !G.flag_SIGINT)
+ if (r == 0) /* keyboard ^C? */
+ continue; /* go back, read another input line */
+ if (r > 0) /* normal input? (no ^C, no ^D, no signals) */
break;
- /* ^C or SIGINT: repeat */
- /* bash prints ^C even on real SIGINT (non-kbd generated) */
- write(STDOUT_FILENO, "^C\n", 3);
- G.last_exitcode = 128 | SIGINT;
- }
- if (r < 0) {
- /* EOF/error detected */
- /* ^D on interactive input goes to next line before exiting: */
- write(STDOUT_FILENO, "\n", 1);
- i->p = NULL;
- i->peek_buf[0] = r = EOF;
- return r;
+ if (!bb_got_signal) {
+ /* r < 0: ^D/EOF/error detected (but not signal) */
+ /* ^D on interactive input goes to next line before exiting: */
+ write(STDOUT_FILENO, "\n", 1);
+ i->p = NULL;
+ i->peek_buf[0] = r = EOF;
+ return r;
+ }
+ /* it was a signal: go back, read another input line */
}
i->p = G.user_input_buf;
return (unsigned char)*i->p++;
@@ -2995,6 +3022,12 @@ static int i_getch(struct in_str *i)
if (ch != '\0') {
i->p++;
i->last_char = ch;
+#if ENABLE_HUSH_LINENO_VAR
+ if (ch == '\n') {
+ G.parse_lineno++;
+ debug_printf_parse("G.parse_lineno++ = %u\n", G.parse_lineno);
+ }
+#endif
return ch;
}
return EOF;
@@ -3642,7 +3675,7 @@ static int glob_brace(char *pattern, o_string *o, int n)
* NEXT points past the terminator of the first element, and REST
* points past the final }. We will accumulate result names from
* recursive runs for each brace alternative in the buffer using
- * GLOB_APPEND. */
+ * GLOB_APPEND. */

p = begin + 1;
while (1) {
@@ -3958,7 +3991,7 @@ static void free_pipe_list(struct pipe *pi)
#ifndef debug_print_tree
static void debug_print_tree(struct pipe *pi, int lvl)
{
- static const char *const PIPE[] = {
+ static const char *const PIPE[] ALIGN_PTR = {
[PIPE_SEQ] = "SEQ",
[PIPE_AND] = "AND",
[PIPE_OR ] = "OR" ,
@@ -3993,7 +4026,7 @@ static void debug_print_tree(struct pipe *pi, int lvl)
[RES_XXXX ] = "XXXX" ,
[RES_SNTX ] = "SNTX" ,
};
- static const char *const CMDTYPE[] = {
+ static const char *const CMDTYPE[] ALIGN_PTR = {
"{}",
"()",
"[noglob]",
@@ -5358,7 +5391,7 @@ static int parse_dollar_squote(o_string *as_string, o_string *dest, struct in_st
# undef as_string
}
#else
-# #define parse_dollar_squote(as_string, dest, input) 0
+# define parse_dollar_squote(as_string, dest, input) 0
#endif /* BASH_DOLLAR_SQUOTE */
#endif /* !__U_BOOT__ */

@@ -6730,7 +6763,7 @@ static char *encode_then_expand_vararg(const char *str, int handle_squotes, int

/* Expanding ARG in ${var+ARG}, ${var-ARG}
*/
-static int encode_then_append_var_plusminus(o_string *output, int n,
+static NOINLINE int encode_then_append_var_plusminus(o_string *output, int n,
char *str, int dquoted)
{
struct in_str input;
@@ -6895,16 +6928,21 @@ static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
/* ${var/[/]pattern[/repl]} helpers */
static char *strstr_pattern(char *val, const char *pattern, int *size)
{
- int sz = strcspn(pattern, "*?[\\");
- if (pattern[sz] == '\0') {
+ int first_escaped = (pattern[0] == '\\' && pattern[1]);
+ /* "first_escaped" trick allows to treat e.g. "\*no_glob_chars"
+ * as literal too (as it is semi-common, and easy to accomodate
+ * by just using str + 1).
+ */
+ int sz = strcspn(pattern + first_escaped * 2, "*?[\\");
+ if ((pattern + first_escaped * 2)[sz] == '\0') {
/* Optimization for trivial patterns.
* Testcase for very slow replace (performs about 22k replaces):
* x=::::::::::::::::::::::
* x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;x=$x$x;echo ${#x}
* echo "${x//:/|}"
*/
- *size = sz;
- return strstr(val, pattern);
+ *size = sz + first_escaped;
+ return strstr(val, pattern + first_escaped);
}

while (1) {
@@ -8025,7 +8063,11 @@ static int parse_and_run_string(const char *s)
#endif /* __U_BOOT__ */
{
struct in_str input;
+#ifndef __U_BOOT__
+ IF_HUSH_LINENO_VAR(unsigned sv = G.parse_lineno;)
+#else /* __U_BOOT__ */
//IF_HUSH_LINENO_VAR(unsigned sv = G.parse_lineno;)
+#endif /* __U_BOOT__ */

setup_string_in_str(&input, s);
#ifndef __U_BOOT__
@@ -8033,7 +8075,11 @@ static int parse_and_run_string(const char *s)
#else /* __U_BOOT__ */
return parse_and_run_stream(&input, '\0');
#endif /* __U_BOOT__ */
- //IF_HUSH_LINENO_VAR(G.parse_lineno = sv;)
+#ifndef __U_BOOT__
+ IF_HUSH_LINENO_VAR(unsigned sv = G.parse_lineno;)
+#else /* __U_BOOT__ */
+ //IF_HUSH_LINENO_VAR(unsigned sv = G.parse_lineno;)
+#endif /* __U_BOOT__ */
}

#ifdef __U_BOOT__
@@ -8141,7 +8187,7 @@ static int generate_stream_from_string(const char *s, pid_t *pid_p)
if (is_prefixed_with(s, "trap")
&& skip_whitespace(s + 4)[0] == '\0'
) {
- static const char *const argv[] = { NULL, NULL };
+ static const char *const argv[] ALIGN_PTR = { NULL, NULL };
builtin_trap((char**)argv);
fflush_all(); /* important */
_exit(0);
@@ -9106,7 +9152,7 @@ static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
* expand_assignments(): think about ... | var=`sleep 1` | ...
*/
free_strings(new_env);
- _exit(EXIT_SUCCESS);
+ _exit_SUCCESS();
}

sv_shadowed = G.shadowed_vars_pp;
@@ -9287,7 +9333,7 @@ static void pseudo_exec(nommu_save_t *nommu_save,

/* Case when we are here: ... | >file */
debug_printf_exec("pseudo_exec'ed null command\n");
- _exit(EXIT_SUCCESS);
+ _exit_SUCCESS();
}

#if ENABLE_HUSH_JOB
@@ -10420,7 +10466,7 @@ static int run_list(struct pipe *pi)
static const char encoded_dollar_at[] ALIGN1 = {
SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
}; /* encoded representation of "$@" */
- static const char *const encoded_dollar_at_argv[] = {
+ static const char *const encoded_dollar_at_argv[] ALIGN_PTR = {
encoded_dollar_at, NULL
}; /* argv list with one element: "$@" */
char **vals;
@@ -10547,7 +10593,12 @@ static int run_list(struct pipe *pi)
G.flag_break_continue = 0;
#endif
#endif /* !__U_BOOT__ */
+#ifndef __U_BOOT__
+ rcode = r = G.o_opt[OPT_O_NOEXEC] ? 0 : run_pipe(pi);
+ /* NB: rcode is a smalluint, r is int */
+#else /* __U_BOOT__ */
rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
+#endif /* __U_BOOT__ */
if (r != -1) {
/* We ran a builtin, function, or group.
* rcode is already known
@@ -10804,7 +10855,10 @@ static int set_mode(int state, char mode, const char *o_opt)
int idx;
switch (mode) {
case 'n':
- G.o_opt[OPT_O_NOEXEC] = state;
+ /* set -n has no effect in interactive shell */
+ /* Try: while set -n; do echo $-; done */
+ if (!G_interactive_fd)
+ G.o_opt[OPT_O_NOEXEC] = state;
break;
case 'x':
IF_HUSH_MODE_X(G_x_mode = state;)
@@ -10877,7 +10931,7 @@ int hush_main(int argc, char **argv)

cached_getpid = getpid(); /* for tcsetpgrp() during init */
G.root_pid = cached_getpid; /* for $PID (NOMMU can override via -$HEXPID:HEXPPID:...) */
- G.root_ppid = getppid(); /* for $PPID (NOMMU can override) */
+ G.root_ppid = getppid(); /* for $PPID (NOMMU can override) */

/* Deal with HUSH_VERSION */
debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
@@ -11008,6 +11062,29 @@ int hush_main(int argc, char **argv)
/* Well, we cannot just declare interactiveness,
* we have to have some stuff (ctty, etc) */
/* G_interactive_fd++; */
+//There are a few cases where bash -i -c 'SCRIPT'
+//has visible effect (differs from bash -c 'SCRIPT'):
+//it ignores TERM:
+// bash -i -c 'kill $$; echo ALIVE'
+// ALIVE
+//it resets SIG_IGNed HUP to SIG_DFL:
+// trap '' hup; bash -i -c 'kill -hup $$; echo ALIVE'
+// Hangup [the message is not printed by bash, it's the shell which started it]
+//is talkative about jobs and exiting:
+// bash -i -c 'sleep 1 & exit'
+// [1] 16170
+// exit
+//includes $ENV file (only if run as "sh"):
+// echo last >/tmp/ENV; ENV=/tmp/ENV sh -i -c 'echo HERE'
+// last: cannot open /var/log/wtmp: No such file or directory
+// HERE
+//(under "bash", it's the opposite: it runs $BASH_ENV file only *without* -i).
+//
+//ash -i -c 'sleep 3; sleep 3', on ^C, drops into a prompt instead of exiting
+//(this may be a bug, bash does not do this).
+//(ash -i -c 'sleep 3' won't show this, the last command gets auto-"exec"ed)
+//
+//None of the above feel like useful features people would rely on.
break;
case 's':
G.opt_s = 1;
@@ -12387,7 +12464,7 @@ static int FAST_FUNC builtin_fg_bg(char **argv)
/* TODO: bash prints a string representation
* of job being foregrounded (like "sleep 1 | cat") */
if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
- /* Put the job into the foreground. */
+ /* Put the job into the foreground. */
tcsetpgrp(G_interactive_fd, pi->pgrp);
}

--
2.25.1