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Fix BRE parentheses #123

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Fix BRE parentheses #123

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99 changes: 45 additions & 54 deletions lib/tre-parse.c
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1218,7 +1218,6 @@ tre_parse(tre_parse_ctx_t *ctx)
switch (*ctx->re)
{
case CHAR_LPAREN: /* parenthesized subexpression */

/* Handle "(?...)" extensions. They work in a way similar
to Perls corresponding extensions. */
if (ctx->cflags & REG_EXTENDED
Expand Down Expand Up @@ -1325,58 +1324,51 @@ tre_parse(tre_parse_ctx_t *ctx)
break;
}

if (ctx->cflags & REG_EXTENDED
|| (ctx->re > ctx->re_start
&& *(ctx->re - 1) == CHAR_BACKSLASH))
if (!(ctx->cflags & REG_EXTENDED))
goto parse_literal;

atom_lparen:
depth++;
if (ctx->re + 2 < ctx->re_end
&& *(ctx->re + 1) == CHAR_QUESTIONMARK
&& *(ctx->re + 2) == CHAR_COLON)
{
depth++;
if (ctx->re + 2 < ctx->re_end
&& *(ctx->re + 1) == CHAR_QUESTIONMARK
&& *(ctx->re + 2) == CHAR_COLON)
{
DPRINT(("tre_parse: group begin: '%.*" STRF
"', no submatch\n", REST(ctx->re)));
/* Don't mark for submatching. */
ctx->re += 3;
STACK_PUSHX(stack, int, PARSE_RE);
}
else
{
DPRINT(("tre_parse: group begin: '%.*" STRF
"', submatch %d\n", REST(ctx->re),
ctx->submatch_id));
ctx->re++;
/* First parse a whole RE, then mark the resulting tree
for submatching. */
STACK_PUSHX(stack, int, ctx->submatch_id);
STACK_PUSHX(stack, int, PARSE_MARK_FOR_SUBMATCH);
STACK_PUSHX(stack, int, PARSE_RE);
ctx->submatch_id++;
}
DPRINT(("tre_parse: group begin: '%.*" STRF
"', no submatch\n", REST(ctx->re)));
/* Don't mark for submatching. */
ctx->re += 3;
STACK_PUSHX(stack, int, PARSE_RE);
}
else
goto parse_literal;
{
DPRINT(("tre_parse: group begin: '%.*" STRF
"', submatch %d\n", REST(ctx->re),
ctx->submatch_id));
ctx->re++;
/* First parse a whole RE, then mark the resulting tree
for submatching. */
STACK_PUSHX(stack, int, ctx->submatch_id);
STACK_PUSHX(stack, int, PARSE_MARK_FOR_SUBMATCH);
STACK_PUSHX(stack, int, PARSE_RE);
ctx->submatch_id++;
}
break;

case CHAR_RPAREN: /* end of current subexpression */
if ((ctx->cflags & REG_EXTENDED && depth > 0)
|| (!(ctx->cflags & REG_EXTENDED) && ctx->re > ctx->re_start
&& *(ctx->re - 1) == CHAR_BACKSLASH))
{
DPRINT(("tre_parse: empty: '%.*" STRF "'\n",
REST(ctx->re)));
/* We were expecting an atom, but instead the current
subexpression was closed. POSIX leaves the meaning of
this to be implementation-defined. We interpret this as
an empty expression (which matches an empty string). */
result = tre_ast_new_literal(ctx->mem, EMPTY, -1);
if (result == NULL)
return REG_ESPACE;
if (!(ctx->cflags & REG_EXTENDED))
ctx->re--;
}
else
if (!(ctx->cflags & REG_EXTENDED) || depth == 0)
goto parse_literal;
atom_rparen:
DPRINT(("tre_parse: empty: '%.*" STRF "'\n",
REST(ctx->re)));
/* We were expecting an atom, but instead the current
subexpression was closed. POSIX leaves the meaning of
this to be implementation-defined. We interpret this as
an empty expression (which matches an empty string). */
result = tre_ast_new_literal(ctx->mem, EMPTY, -1);
if (result == NULL)
return REG_ESPACE;
if (!(ctx->cflags & REG_EXTENDED))
ctx->re--;
break;

case CHAR_LBRACKET: /* bracket expression */
Expand All @@ -1389,16 +1381,15 @@ tre_parse(tre_parse_ctx_t *ctx)
break;

case CHAR_BACKSLASH:
/* If this is "\(" or "\)" chew off the backslash and
try again. */
if (!(ctx->cflags & REG_EXTENDED)
&& ctx->re + 1 < ctx->re_end
&& (*(ctx->re + 1) == CHAR_LPAREN
|| *(ctx->re + 1) == CHAR_RPAREN))
/* If this is "\(" or "\)" skip straight there. */
if (!(ctx->cflags & REG_EXTENDED) && ctx->re + 1 < ctx->re_end)
{
ctx->re++;
STACK_PUSHX(stack, int, PARSE_ATOM);
break;
if (*ctx->re == CHAR_LPAREN)
goto atom_lparen;
if (*ctx->re == CHAR_RPAREN)
goto atom_rparen;
ctx->re--;
}

/* If a macro is used, parse the expanded macro recursively. */
Expand Down
7 changes: 6 additions & 1 deletion tests/retest.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1166,7 +1166,12 @@ main(int argc, char **argv)
test_comp("[[.", 0, REG_ECOLLATE);
test_comp("[[=", 0, REG_ECOLLATE);


/* BRE parentheses. */
test_comp("\\\\(a", 0, 0);
test_exec("\\(a", 0, REG_OK, 0, 3, END);
test_comp("\\(a\\\\)\\)", 0, 0);
test_exec("a\\)", 0, REG_OK, 0, 3, 0, 3, END);
test_comp("\\(\\\\)", 0, REG_EPAREN);

/* Miscellaneous tests. */
test_comp("abc\\(\\(de\\)\\(fg\\)\\)hi", 0, 0);
Expand Down
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