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hush: optimize parse_stream()

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Since we check for '\' anyway when we determine whether we can look ahead,
we can just check for *and handle* it there.

function                                             old     new   delta
parse_stream                                        2751    2740     -11

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2018-04-11 01:33:54 +02:00
parent 89e9d5534d
commit 0403bedccc
1 changed files with 31 additions and 28 deletions
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59
shell/hush.c
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@ -5076,6 +5076,14 @@ static struct pipe *parse_stream(char **pstring,
}
nommu_addchr(&ctx.as_string, ch);
/* Handle "'" and "\" first, as they won't play nice with
* i_peek_and_eat_bkslash_nl() anyway:
* echo z\\
* and
* echo '\
* '
* would break.
*/
if (ch == '\'') {
ctx.word.has_quoted_part = 1;
next = i_getch(input);
@ -5101,19 +5109,34 @@ static struct pipe *parse_stream(char **pstring,
}
continue; /* get next char */
}
if (ch == '\\') {
/*nommu_addchr(&ctx.as_string, '\\'); - already done */
o_addchr(&ctx.word, '\\');
ch = i_getch(input);
if (ch == EOF) {
/* Testcase: eval 'echo Ok\' */
next = '\0';
if (ch != '\n' && ch != '\\') {
/* Not on '\': do not break the case of "echo z\\":
* on 2nd '\', i_peek_and_eat_bkslash_nl()
* would stop and try to read next line,
* not letting the command to execute.
#if 0 /* bash-4.3.43 was removing backslash, but 4.4.19 retains it, most other shells too */
/* Remove trailing '\' from ctx.as_string */
ctx.as_string.data[--ctx.as_string.length] = '\0';
#endif
continue; /* get next char */
}
/* Example: echo Hello \2>file
* we need to know that word 2 is quoted
*/
next = i_peek_and_eat_bkslash_nl(input);
ctx.word.has_quoted_part = 1;
nommu_addchr(&ctx.as_string, ch);
o_addchr(&ctx.word, ch);
continue; /* get next char */
}
next = '\0';
if (ch != '\n')
next = i_peek_and_eat_bkslash_nl(input);
is_special = "{}<>;&|()#" /* special outside of "str" */
"\\$\"" IF_HUSH_TICK("`") /* always special */
"$\"" IF_HUSH_TICK("`") /* always special */
SPECIAL_VAR_SYMBOL_STR;
/* Are { and } special here? */
if (ctx.command->argv /* word [word]{... - non-special */
@ -5401,26 +5424,6 @@ static struct pipe *parse_stream(char **pstring,
/* non-comment #: "echo a#b" etc */
o_addchr(&ctx.word, ch);
continue; /* get next char */
case '\\':
/*nommu_addchr(&ctx.as_string, '\\'); - already done */
o_addchr(&ctx.word, '\\');
ch = i_getch(input);
if (ch == EOF) {
/* Testcase: eval 'echo Ok\' */
#if 0 /* bash-4.3.43 was removing backslash, but 4.4.19 retains it, most other shells too */
/* Remove trailing '\' from ctx.as_string */
ctx.as_string.data[--ctx.as_string.length] = '\0';
#endif
continue; /* get next char */
}
/* Example: echo Hello \2>file
* we need to know that word 2 is quoted
*/
ctx.word.has_quoted_part = 1;
nommu_addchr(&ctx.as_string, ch);
o_addchr(&ctx.word, ch);
continue; /* get next char */
case '$':
if (!parse_dollar(&ctx.as_string, &ctx.word, input, /*quote_mask:*/ 0)) {
debug_printf_parse("parse_stream parse error: "