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ash: remove parsebackquote flag

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Commit 503a0b8 from git://git.kernel.org/pub/scm/utils/dash/dash.git
by Herbert Xu says:

  >The parsebackquote flag is only used in a test where it always has the
  >value zero.  So we can remove it altogether.

The first statement is incorrect:  parsebackquote is non-zero when
backquotes (as opposed to $(...)) are used for command substitution.
It is possible for the test to be executed with parsebackquote != 0 in
that case.

The test is question checks whether quotes have been closed, raising
the error "unterminated quoted string" if they haven't.  There seems
to be no good reason to allow unclosed quotes within backquotes.  Bash,
hush and dash (after commit 503a0b8) all treat the following as an error:

   XX=`"pwd`

whereas BusyBox ash doesn't.  It just ignores the unclosed quote and
executes pwd.

So, parsebackquote should be removed but not for the reason stated.

function                                             old     new   delta
parsebackquote                                         1       -      -1
readtoken1                                          3222    3182     -40
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 0/1 up/down: 0/-41)             Total: -41 bytes

Signed-off-by: Ron Yorston <rmy@frippery.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Ron Yorston 2015-07-01 16:45:40 +01:00 committed by Denys Vlasenko
parent 97f2f7ca7f
commit 0e056f7e9e
3 changed files with 3 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
shell/ash.c
View File

@ -10473,7 +10473,6 @@ struct heredoc {
}; };
static smallint tokpushback; /* last token pushed back */ static smallint tokpushback; /* last token pushed back */
static smallint parsebackquote; /* nonzero if we are inside backquotes */
static smallint quoteflag; /* set if (part of) last token was quoted */ static smallint quoteflag; /* set if (part of) last token was quoted */
static token_id_t lasttoken; /* last token read (integer id Txxx) */ static token_id_t lasttoken; /* last token read (integer id Txxx) */
static struct heredoc *heredoclist; /* list of here documents to read */ static struct heredoc *heredoclist; /* list of here documents to read */
@ -11313,7 +11312,7 @@ readtoken1(int c, int syntax, char *eofmark, int striptabs)
if (syntax == ARISYNTAX) if (syntax == ARISYNTAX)
raise_error_syntax("missing '))'"); raise_error_syntax("missing '))'");
#endif #endif
if (syntax != BASESYNTAX && !parsebackquote && eofmark == NULL) if (syntax != BASESYNTAX && eofmark == NULL)
raise_error_syntax("unterminated quoted string"); raise_error_syntax("unterminated quoted string");
if (varnest != 0) { if (varnest != 0) {
startlinno = g_parsefile->linno; startlinno = g_parsefile->linno;
@ -11609,7 +11608,6 @@ parsesub: {
*/ */
parsebackq: { parsebackq: {
struct nodelist **nlpp; struct nodelist **nlpp;
smallint savepbq;
union node *n; union node *n;
char *volatile str; char *volatile str;
struct jmploc jmploc; struct jmploc jmploc;
@ -11620,10 +11618,8 @@ parsebackq: {
#ifdef __GNUC__ #ifdef __GNUC__
(void) &saveprompt; (void) &saveprompt;
#endif #endif
savepbq = parsebackquote;
if (setjmp(jmploc.loc)) { if (setjmp(jmploc.loc)) {
free(str); free(str);
parsebackquote = 0;
exception_handler = savehandler; exception_handler = savehandler;
longjmp(exception_handler->loc, 1); longjmp(exception_handler->loc, 1);
} }
@ -11707,7 +11703,6 @@ parsebackq: {
nlpp = &(*nlpp)->next; nlpp = &(*nlpp)->next;
*nlpp = stzalloc(sizeof(**nlpp)); *nlpp = stzalloc(sizeof(**nlpp));
/* (*nlpp)->next = NULL; - stzalloc did it */ /* (*nlpp)->next = NULL; - stzalloc did it */
parsebackquote = oldstyle;
if (oldstyle) { if (oldstyle) {
saveprompt = doprompt; saveprompt = doprompt;
@ -11741,7 +11736,6 @@ parsebackq: {
str = NULL; str = NULL;
INT_ON; INT_ON;
} }
parsebackquote = savepbq;
exception_handler = savehandler; exception_handler = savehandler;
USTPUTC(CTLBACKQ, out); USTPUTC(CTLBACKQ, out);
if (oldstyle) if (oldstyle)

1
shell/ash_test/ash-misc/tickquote1.right Normal file
View File

@ -0,0 +1 @@
./tickquote1.tests: line 1: syntax error: unterminated quoted string

1
shell/ash_test/ash-misc/tickquote1.tests Executable file
View File

@ -0,0 +1 @@
echo `"pwd`