ash: move parse-time quote flag detection to run-time
Because the parser does not recursively parse parameter expansion
with respect to quotes, we can't accurately determine quote status at
parse time. This patch works around this by moving the quote detection
to run-time where we do interpret it recursively.
Test case:
foo=\\ echo "<${foo#[\\]}>"
Old result:
<\>
New result:
<>
Do not quote back slashes in parameter expansions outside quotes.
Test case:
a=/b/c/*
b=\\
echo ${a%$b*}
Old result:
/b/c/*
New result:
/b/c/
Based on commits 880d952, 7cfd8be, 0d7d660 and a7c21a6 from
git://git.kernel.org/pub/scm/utils/dash/dash.git by Herbert Xu
function old new delta
argstr 1164 1193 +29
memtodest 147 174 +27
subevalvar 1153 1177 +24
redirect 1279 1282 +3
dolatstr 5 7 +2
static.spclchars 10 9 -1
expandarg 962 960 -2
evalcase 273 271 -2
evalcommand 1204 1197 -7
rmescapes 236 227 -9
preglob 27 8 -19
evalvar 604 582 -22
cmdputs 389 334 -55
readtoken1 3163 3061 -102
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 5/9 up/down: 85/-219) Total: -134 bytes
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/shell/ash.c b/shell/ash.c
index 33a477d..e7e7081 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -598,8 +598,6 @@
#define CTLVAR ((unsigned char)'\202') /* variable defn */
#define CTLENDVAR ((unsigned char)'\203')
#define CTLBACKQ ((unsigned char)'\204')
-#define CTLQUOTE 01 /* ored with CTLBACKQ code if in quotes */
-/* CTLBACKQ | CTLQUOTE == '\205' */
#define CTLARI ((unsigned char)'\206') /* arithmetic expression */
#define CTLENDARI ((unsigned char)'\207')
#define CTLQUOTEMARK ((unsigned char)'\210')
@@ -608,7 +606,6 @@
/* variable substitution byte (follows CTLVAR) */
#define VSTYPE 0x0f /* type of variable substitution */
#define VSNUL 0x10 /* colon--treat the empty string as unset */
-#define VSQUOTE 0x80 /* inside double quotes--suppress splitting */
/* values of VSTYPE field */
#define VSNORMAL 0x1 /* normal variable: $var or ${var} */
@@ -628,8 +625,9 @@
#endif
static const char dolatstr[] ALIGN1 = {
- CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0'
+ CTLQUOTEMARK, CTLVAR, VSNORMAL, '@', '=', CTLQUOTEMARK, '\0'
};
+#define DOLATSTRLEN 6
#define NCMD 0
#define NPIPE 1
@@ -865,9 +863,7 @@
case '\\': c = '\\'; goto backslash;
case CTLESC: c = 'e'; goto backslash;
case CTLVAR: c = 'v'; goto backslash;
- case CTLVAR+CTLQUOTE: c = 'V'; goto backslash;
case CTLBACKQ: c = 'q'; goto backslash;
- case CTLBACKQ+CTLQUOTE: c = 'Q'; goto backslash;
backslash:
putc('\\', tracefile);
putc(c, tracefile);
@@ -1030,7 +1026,6 @@
putc('}', fp);
break;
case CTLBACKQ:
- case CTLBACKQ|CTLQUOTE:
putc('$', fp);
putc('(', fp);
shtree(bqlist->n, -1, NULL, fp);
@@ -4413,11 +4408,7 @@
str = "${#";
else
str = "${";
- if (!(subtype & VSQUOTE) == !(quoted & 1))
- goto dostr;
- quoted ^= 1;
- c = '"';
- break;
+ goto dostr;
case CTLENDVAR:
str = "\"}" + !(quoted & 1);
quoted >>= 1;
@@ -4426,9 +4417,6 @@
case CTLBACKQ:
str = "$(...)";
goto dostr;
- case CTLBACKQ+CTLQUOTE:
- str = "\"$(...)\"";
- goto dostr;
#if ENABLE_SH_MATH_SUPPORT
case CTLARI:
str = "$((";
@@ -5526,7 +5514,7 @@
#define EXP_VARTILDE 0x4 /* expand tildes in an assignment */
#define EXP_REDIR 0x8 /* file glob for a redirection (1 match only) */
#define EXP_CASE 0x10 /* keeps quotes around for CASE pattern */
-#define EXP_RECORD 0x20 /* need to record arguments for ifs breakup */
+#define EXP_QPAT 0x20 /* pattern in quoted parameter expansion */
#define EXP_VARTILDE2 0x40 /* expand tildes after colons only */
#define EXP_WORD 0x80 /* expand word in parameter expansion */
#define EXP_QUOTED 0x100 /* expand word in double quotes */
@@ -5535,12 +5523,11 @@
*/
#define RMESCAPE_ALLOC 0x1 /* Allocate a new string */
#define RMESCAPE_GLOB 0x2 /* Add backslashes for glob */
-#define RMESCAPE_QUOTED 0x4 /* Remove CTLESC unless in quotes */
#define RMESCAPE_GROW 0x8 /* Grow strings instead of stalloc */
#define RMESCAPE_HEAP 0x10 /* Malloc strings instead of stalloc */
/* Add CTLESC when necessary. */
-#define QUOTES_ESC (EXP_FULL | EXP_CASE | EXP_REDIR)
+#define QUOTES_ESC (EXP_FULL | EXP_CASE | EXP_QPAT | EXP_REDIR)
/* Do not skip NUL characters. */
#define QUOTES_KEEPNUL EXP_TILDE
@@ -5641,13 +5628,11 @@
}
}
- inquotes = (flag & RMESCAPE_QUOTED) ^ RMESCAPE_QUOTED;
+ inquotes = 0;
globbing = flag & RMESCAPE_GLOB;
protect_against_glob = globbing;
while (*p) {
if ((unsigned char)*p == CTLQUOTEMARK) {
-// TODO: if no RMESCAPE_QUOTED in flags, inquotes never becomes 0
-// (alternates between RMESCAPE_QUOTED and ~RMESCAPE_QUOTED). Is it ok?
// Note: both inquotes and protect_against_glob only affect whether
// CTLESC,<ch> gets converted to <ch> or to \<ch>
inquotes = ~inquotes;
@@ -5655,17 +5640,16 @@
protect_against_glob = globbing;
continue;
}
- if (*p == '\\') {
+ if ((unsigned char)*p == CTLESC) {
+ p++;
+ if (protect_against_glob) {
+ *q++ = '\\';
+ }
+ } else if (*p == '\\' && !inquotes) {
/* naked back slash */
protect_against_glob = 0;
goto copy;
}
- if ((unsigned char)*p == CTLESC) {
- p++;
- if (protect_against_glob && inquotes && *p != '/') {
- *q++ = '\\';
- }
- }
protect_against_glob = globbing;
copy:
*q++ = *p++;
@@ -5685,13 +5669,9 @@
* Returns an stalloced string.
*/
static char *
-preglob(const char *pattern, int quoted, int flag)
+preglob(const char *pattern, int flag)
{
- flag |= RMESCAPE_GLOB;
- if (quoted) {
- flag |= RMESCAPE_QUOTED;
- }
- return rmescapes((char *)pattern, flag);
+ return rmescapes((char *)pattern, flag | RMESCAPE_GLOB);
}
/*
@@ -5712,7 +5692,9 @@
if (c) {
int n = SIT(c, syntax);
if ((quotes & QUOTES_ESC) &&
- (n == CCTL || n == CBACK))
+ ((n == CCTL) ||
+ (((quotes & EXP_FULL) || syntax != BASESYNTAX) &&
+ n == CBACK)))
USTPUTC(CTLESC, q);
} else if (!(quotes & QUOTES_KEEPNUL))
continue;
@@ -5905,7 +5887,7 @@
* Expand stuff in backwards quotes.
*/
static void
-expbackq(union node *cmd, int quoted, int quotes)
+expbackq(union node *cmd, int flag)
{
struct backcmd in;
int i;
@@ -5913,7 +5895,7 @@
char *p;
char *dest;
int startloc;
- int syntax = quoted ? DQSYNTAX : BASESYNTAX;
+ int syntax = flag & EXP_QUOTED ? DQSYNTAX : BASESYNTAX;
struct stackmark smark;
INT_OFF;
@@ -5929,7 +5911,7 @@
if (i == 0)
goto read;
for (;;) {
- memtodest(p, i, syntax, quotes);
+ memtodest(p, i, syntax, flag & QUOTES_ESC);
read:
if (in.fd < 0)
break;
@@ -5953,7 +5935,7 @@
STUNPUTC(dest);
expdest = dest;
- if (quoted == 0)
+ if (!(flag & EXP_QUOTED))
recordregion(startloc, dest - (char *)stackblock(), 0);
TRACE(("evalbackq: size:%d:'%.*s'\n",
(int)((dest - (char *)stackblock()) - startloc),
@@ -5967,11 +5949,10 @@
* evaluate, place result in (backed up) result, adjust string position.
*/
static void
-expari(int quotes)
+expari(int flag)
{
char *p, *start;
int begoff;
- int flag;
int len;
/* ifsfree(); */
@@ -6009,16 +5990,14 @@
removerecordregions(begoff);
- flag = p[1];
-
expdest = p;
- if (quotes)
- rmescapes(p + 2, 0);
+ if (flag & QUOTES_ESC)
+ rmescapes(p + 1, 0);
- len = cvtnum(ash_arith(p + 2));
+ len = cvtnum(ash_arith(p + 1));
- if (flag != '"')
+ if (!(flag & EXP_QUOTED))
recordregion(begoff, begoff + len, 0);
}
#endif
@@ -6046,14 +6025,12 @@
CTLESC,
CTLVAR,
CTLBACKQ,
- CTLBACKQ | CTLQUOTE,
#if ENABLE_SH_MATH_SUPPORT
CTLENDARI,
#endif
'\0'
};
const char *reject = spclchars;
- int quotes = flags & QUOTES_ESC;
int breakall = (flags & (EXP_WORD | EXP_QUOTED)) == EXP_WORD;
int inquotes;
size_t length;
@@ -6128,19 +6105,14 @@
case CTLENDVAR: /* ??? */
goto breakloop;
case CTLQUOTEMARK:
+ inquotes ^= EXP_QUOTED;
/* "$@" syntax adherence hack */
- if (!inquotes
- && memcmp(p, dolatstr, 4) == 0
- && ( p[4] == (char)CTLQUOTEMARK
- || (p[4] == (char)CTLENDVAR && p[5] == (char)CTLQUOTEMARK)
- )
- ) {
- p = evalvar(p + 1, flags, /* var_str_list: */ NULL) + 1;
+ if (inquotes && !memcmp(p, dolatstr + 1, DOLATSTRLEN - 1)) {
+ p = evalvar(p + 1, flags | inquotes, /* var_str_list: */ NULL) + 1;
goto start;
}
- inquotes = !inquotes;
addquote:
- if (quotes) {
+ if (flags & QUOTES_ESC) {
p--;
length++;
startloc++;
@@ -6149,22 +6121,30 @@
case CTLESC:
startloc++;
length++;
+
+ /*
+ * Quoted parameter expansion pattern: remove quote
+ * unless inside inner quotes or we have a literal
+ * backslash.
+ */
+ if (((flags | inquotes) & (EXP_QPAT | EXP_QUOTED)) ==
+ EXP_QPAT && *p != '\\')
+ break;
+
goto addquote;
case CTLVAR:
TRACE(("argstr: evalvar('%s')\n", p));
- p = evalvar(p, flags, var_str_list);
+ p = evalvar(p, flags | inquotes, var_str_list);
TRACE(("argstr: evalvar:'%s'\n", (char *)stackblock()));
goto start;
case CTLBACKQ:
- c = '\0';
- case CTLBACKQ|CTLQUOTE:
- expbackq(argbackq->n, c, quotes);
+ expbackq(argbackq->n, flags | inquotes);
argbackq = argbackq->next;
goto start;
#if ENABLE_SH_MATH_SUPPORT
case CTLENDARI:
p--;
- expari(quotes);
+ expari(flags | inquotes);
goto start;
#endif
}
@@ -6296,13 +6276,13 @@
#if ENABLE_ASH_BASH_COMPAT
static char *
-parse_sub_pattern(char *arg, int varflags)
+parse_sub_pattern(char *arg, int quoted)
{
char *idx, *repl = NULL;
unsigned char c;
//char *org_arg = arg;
- //bb_error_msg("arg:'%s' varflags:%x", arg, varflags);
+ //bb_error_msg("arg:'%s' quoted:%x", arg, quoted);
idx = arg;
while (1) {
c = *arg;
@@ -6318,7 +6298,7 @@
*idx++ = c;
arg++;
/*
- * Example: v='ab\c'; echo ${v/\\b/_\\_\z_}
+ * Example: v='a\bc'; echo ${v/\\b/_\\_\z_}
* The result is a_\_z_c (not a\_\_z_c)!
*
* Enable debug prints in this function and you'll see:
@@ -6328,7 +6308,7 @@
* IOW: search pattern and replace string treat backslashes
* differently! That is the reason why we check repl below:
*/
- if (c == '\\' && *arg == '\\' && repl && !(varflags & VSQUOTE))
+ if (c == '\\' && *arg == '\\' && repl && !quoted)
arg++; /* skip both '\', not just first one */
}
*idx = c; /* NUL */
@@ -6340,9 +6320,10 @@
static const char *
subevalvar(char *p, char *varname, int strloc, int subtype,
- int startloc, int varflags, int quotes, struct strlist *var_str_list)
+ int startloc, int varflags, int flag, struct strlist *var_str_list)
{
struct nodelist *saveargbackq = argbackq;
+ int quotes = flag & QUOTES_ESC;
char *startp;
char *loc;
char *rmesc, *rmescend;
@@ -6360,7 +6341,8 @@
herefd = -1;
argstr(p, EXP_TILDE | (subtype != VSASSIGN && subtype != VSQUESTION ?
- EXP_CASE : 0), var_str_list);
+ (flag & (EXP_QUOTED | EXP_QPAT) ? EXP_QPAT : EXP_CASE) : 0),
+ var_str_list);
STPUTC('\0', expdest);
herefd = saveherefd;
argbackq = saveargbackq;
@@ -6471,7 +6453,7 @@
}
rmescend--;
str = (char *)stackblock() + strloc;
- preglob(str, varflags & VSQUOTE, 0);
+ preglob(str, 0);
#if ENABLE_ASH_BASH_COMPAT
workloc = expdest - (char *)stackblock();
@@ -6479,7 +6461,7 @@
char *idx, *end;
if (!repl) {
- repl = parse_sub_pattern(str, varflags);
+ repl = parse_sub_pattern(str, flag & EXP_QUOTED);
//bb_error_msg("repl:'%s'", repl);
if (!repl)
repl = nullstr;
@@ -6618,7 +6600,7 @@
int i;
ssize_t len = 0;
int sep;
- int quoted = varflags & VSQUOTE;
+ int quoted = flags & EXP_QUOTED;
int subtype = varflags & VSTYPE;
int discard = subtype == VSPLUS || subtype == VSLENGTH;
int quotes = (discard ? 0 : (flags & QUOTES_ESC)) | QUOTES_KEEPNUL;
@@ -6758,7 +6740,7 @@
{
char varflags;
char subtype;
- char quoted;
+ int quoted;
char easy;
char *var;
int patloc;
@@ -6767,7 +6749,7 @@
varflags = (unsigned char) *p++;
subtype = varflags & VSTYPE;
- quoted = varflags & VSQUOTE;
+ quoted = flags & EXP_QUOTED;
var = p;
easy = (!quoted || (*var == '@' && shellparam.nparam));
startloc = expdest - (char *)stackblock();
@@ -6788,7 +6770,7 @@
if (varlen < 0) {
argstr(
p,
- flags | EXP_TILDE | EXP_WORD | (quoted ? EXP_QUOTED : 0),
+ flags | EXP_TILDE | EXP_WORD,
var_str_list
);
goto end;
@@ -6802,7 +6784,7 @@
if (varlen < 0) {
if (subevalvar(p, var, /* strloc: */ 0,
subtype, startloc, varflags,
- /* quotes: */ 0,
+ /* quotes: */ flags & ~QUOTES_ESC,
var_str_list)
) {
varflags &= ~VSNUL;
@@ -6859,10 +6841,7 @@
STPUTC('\0', expdest);
patloc = expdest - (char *)stackblock();
if (NULL == subevalvar(p, /* varname: */ NULL, patloc, subtype,
- startloc, varflags,
- /* quotes: */ flags & QUOTES_ESC,
- var_str_list)
- ) {
+ startloc, varflags, flags, var_str_list)) {
int amount = expdest - (
(char *)stackblock() + patloc - 1
);
@@ -6881,7 +6860,7 @@
unsigned char c = *p++;
if (c == CTLESC)
p++;
- else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) {
+ else if (c == CTLBACKQ) {
if (varlen >= 0)
argbackq = argbackq->next;
} else if (c == CTLVAR) {
@@ -7217,7 +7196,7 @@
savelastp = exparg.lastp;
INT_OFF;
- p = preglob(str->text, 0, RMESCAPE_ALLOC | RMESCAPE_HEAP);
+ p = preglob(str->text, RMESCAPE_ALLOC | RMESCAPE_HEAP);
{
int i = strlen(str->text);
expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */
@@ -7307,7 +7286,7 @@
expandhere(union node *arg, int fd)
{
herefd = fd;
- expandarg(arg, (struct arglist *)NULL, 0);
+ expandarg(arg, (struct arglist *)NULL, EXP_QUOTED);
full_write(fd, stackblock(), expdest - (char *)stackblock());
}
@@ -7317,7 +7296,7 @@
static int
patmatch(char *pattern, const char *string)
{
- return pmatch(preglob(pattern, 0, 0), string);
+ return pmatch(preglob(pattern, 0), string);
}
/*
@@ -8570,7 +8549,7 @@
arglist.list = NULL;
arglist.lastp = &arglist.list;
for (argp = n->nfor.args; argp; argp = argp->narg.next) {
- expandarg(argp, &arglist, EXP_FULL | EXP_TILDE | EXP_RECORD);
+ expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
/* XXX */
if (evalskip)
goto out;
@@ -11260,11 +11239,9 @@
&& c != '$'
&& (c != '"' || eofmark != NULL)
) {
- USTPUTC(CTLESC, out);
USTPUTC('\\', out);
}
- if (SIT(c, SQSYNTAX) == CCTL)
- USTPUTC(CTLESC, out);
+ USTPUTC(CTLESC, out);
USTPUTC(c, out);
quotef = 1;
}
@@ -11637,8 +11614,6 @@
do_pungetc:
pungetc();
}
- if (dblquote || arinest)
- flags |= VSQUOTE;
((unsigned char *)stackblock())[typeloc] = subtype | flags;
if (subtype != VSNORMAL) {
varnest++;
@@ -11792,10 +11767,7 @@
}
parsebackquote = savepbq;
exception_handler = savehandler;
- if (arinest || dblquote)
- USTPUTC(CTLBACKQ | CTLQUOTE, out);
- else
- USTPUTC(CTLBACKQ, out);
+ USTPUTC(CTLBACKQ, out);
if (oldstyle)
goto parsebackq_oldreturn;
goto parsebackq_newreturn;
@@ -11811,10 +11783,6 @@
syntax = ARISYNTAX;
}
USTPUTC(CTLARI, out);
- if (dblquote)
- USTPUTC('"', out);
- else
- USTPUTC(' ', out);
goto parsearith_return;
}
#endif
@@ -12129,7 +12097,7 @@
n.narg.text = wordtext;
n.narg.backquote = backquotelist;
- expandarg(&n, NULL, 0);
+ expandarg(&n, NULL, EXP_QUOTED);
return stackblock();
}
#endif
diff --git a/shell/ash_test/ash-vars/var-do-not-quote-backslashes-in-parameter-expansions-outside-quotes.right b/shell/ash_test/ash-vars/var-do-not-quote-backslashes-in-parameter-expansions-outside-quotes.right
new file mode 100644
index 0000000..030ebde
--- /dev/null
+++ b/shell/ash_test/ash-vars/var-do-not-quote-backslashes-in-parameter-expansions-outside-quotes.right
@@ -0,0 +1 @@
+/b/c/
diff --git a/shell/ash_test/ash-vars/var-do-not-quote-backslashes-in-parameter-expansions-outside-quotes.tests b/shell/ash_test/ash-vars/var-do-not-quote-backslashes-in-parameter-expansions-outside-quotes.tests
new file mode 100755
index 0000000..fb93714
--- /dev/null
+++ b/shell/ash_test/ash-vars/var-do-not-quote-backslashes-in-parameter-expansions-outside-quotes.tests
@@ -0,0 +1,3 @@
+a=/b/c/*
+b=\\
+echo ${a%$b*}
diff --git a/shell/ash_test/ash-vars/var-runtime-quote-detection.right b/shell/ash_test/ash-vars/var-runtime-quote-detection.right
new file mode 100644
index 0000000..b554d9e
--- /dev/null
+++ b/shell/ash_test/ash-vars/var-runtime-quote-detection.right
@@ -0,0 +1 @@
+<>
diff --git a/shell/ash_test/ash-vars/var-runtime-quote-detection.tests b/shell/ash_test/ash-vars/var-runtime-quote-detection.tests
new file mode 100755
index 0000000..e570631
--- /dev/null
+++ b/shell/ash_test/ash-vars/var-runtime-quote-detection.tests
@@ -0,0 +1 @@
+foo=\\ echo "<${foo#[\\]}>"