From 8a6a4615048d51af0e765e893211073faa7951cc Mon Sep 17 00:00:00 2001
From: Denys Vlasenko <vda.linux@googlemail.com>
Date: Thu, 19 Jul 2018 12:14:47 +0200
Subject: hush: propagate (output,n) parameters into expand_one_var()
This is necessary since expand_one_var() for ${var:+ARG} must create more than one
output word, and thus can't simply return a char*.
function old new delta
expand_one_var 1610 1643 +33
expand_vars_to_list 1139 1125 -14
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 33/-14) Total: 19 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
---
shell/hush.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++--------------
1 file changed, 49 insertions(+), 14 deletions(-)
diff --git a/shell/hush.c b/shell/hush.c
index b738d2fd8..ea259f53c 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -5976,7 +5976,8 @@ static int append_str_maybe_ifs_split(o_string *output, int *ended_in_ifs, int n
/* Helper:
* Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
*/
-static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
+static NOINLINE int expand_one_var(o_string *output,
+ int *ended_in_ifs, int n, int first_ch, char *arg, char **pp)
{
const char *val;
char *to_be_freed;
@@ -6038,9 +6039,9 @@ static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, cha
/* Look up the variable in question */
if (isdigit(var[0])) {
/* parse_dollar should have vetted var for us */
- int n = xatoi_positive(var);
- if (n < G.global_argc)
- val = G.global_argv[n];
+ int nn = xatoi_positive(var);
+ if (nn < G.global_argc)
+ val = G.global_argv[nn];
/* else val remains NULL: $N with too big N */
} else {
switch (var[0]) {
@@ -6236,6 +6237,34 @@ static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, cha
* Colon forms (${var:-word}, ${var:=word} etc) do the same,
* but also treat null var as if it is unset.
*/
+/*
+ * Word-splitting and squote behavior of bash:
+ * $ f() { for i; do echo "|$i|"; done; };
+ *
+ * $ x=; f ${x:?'x y' z}
+ * bash: x: x y z
+ * $ x=; f "${x:?'x y' z}"
+ * bash: x: x y z # dash prints: dash: x: 'x y' z
+ *
+ * $ x=; f ${x:='x y' z}
+ * |x|
+ * |y|
+ * |z|
+ * $ x=; f "${x:='x y' z}"
+ * |'x y' z|
+ *
+ * $ x=x; f ${x:+'x y' z}
+ * |x y|
+ * |z|
+ * $ x=x; f "${x:+'x y' z}"
+ * |'x y' z|
+ *
+ * $ x=; f ${x:-'x y' z}
+ * |x y|
+ * |z|
+ * $ x=; f "${x:-'x y' z}"
+ * |'x y' z|
+ */
int use_word = (!val || ((exp_save == ':') && !val[0]));
if (exp_op == '+')
use_word = !use_word;
@@ -6244,7 +6273,10 @@ static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, cha
if (use_word) {
//FIXME: unquoted ${x:+"b c" d} and ${x:+'b c' d} should expand to two words
//currently it expands to three.
- to_be_freed = encode_then_expand_vararg(exp_word, /*handle_squotes:*/ !(arg0 & 0x80), /*unbackslash:*/ 0);
+ to_be_freed = encode_then_expand_vararg(exp_word,
+ /*handle_squotes:*/ !(arg0 & 0x80),
+ /*unbackslash:*/ 0
+ );
if (to_be_freed)
exp_word = to_be_freed;
if (exp_op == '?') {
@@ -6258,6 +6290,11 @@ static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, cha
/*: (exp_save == ':' ? "parameter null or not set" : "parameter not set")*/
);
//TODO: how interactive bash aborts expansion mid-command?
+//It aborts the entire line:
+// $ f() { for i; do echo "|$i|"; done; }; x=; f "${x:?'x y' z}"; echo YO
+// bash: x: x y z
+// $
+// ("echo YO" is not executed, neither the f function call)
} else {
val = exp_word;
}
@@ -6280,10 +6317,12 @@ static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, cha
} /* if (exp_op) */
arg[0] = arg0;
-
*pp = p;
- *to_be_freed_pp = to_be_freed;
- return val;
+
+ n = append_str_maybe_ifs_split(output, ended_in_ifs, n, first_ch, val);
+
+ free(to_be_freed);
+ return n;
}
/* Expand all variable references in given string, adding words to list[]
@@ -6427,13 +6466,9 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
break;
}
#endif
- default: {
- char *to_be_freed;
- val = expand_one_var(&to_be_freed, arg, &p);
- n = append_str_maybe_ifs_split(output, &ended_in_ifs, n, first_ch, val);
- free(to_be_freed);
+ default:
+ n = expand_one_var(output, &ended_in_ifs, n, first_ch, arg, &p);
goto restore;
- } /* default: */
} /* switch (char after <SPECIAL_VAR_SYMBOL>) */
if (val && val[0]) {
--
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