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Merged
zherczeg merged 1 commit into from
Oct 29, 2026
Merged

Reject single character optimizations which affected by control verbs #1050

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113 changes: 68 additions & 45 deletions src/pcre2_jit_compile.c
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Original file line number Diff line number Diff line change
Expand Up @@ -219,6 +219,8 @@ typedef struct stub_list {

enum frame_types { no_frame = -1, no_stack = -2 };

enum verb_offset_types { verb_offset_then = 0x1, verb_offset_any = 0x2 };

enum control_types { type_mark = 0, type_then_trap = 1 };

enum early_fail_types { type_skip = 0, type_fail = 1, type_fail_range = 2 };
Expand Down Expand Up @@ -403,7 +405,7 @@ typedef struct compiler_common {
/* Bitset for tracking capture bracket status. */
sljit_u8 *cbracket_bitset;
/* Tells whether the starting offset is a target of then. */
sljit_u8 *then_offsets;
sljit_u8 *verb_offsets;
/* Current position where a THEN must jump. */
then_trap_backtrack *then_trap;
/* Starting offset of private data for capturing brackets. */
Expand Down Expand Up @@ -1302,31 +1304,40 @@ check_opcode_types(compiler_common *common, PCRE2_SPTR cc, PCRE2_SPTR ccend)
cc += 1 + LINK_SIZE;
break;

case OP_THEN:
common->has_then = TRUE;
common->control_head_ptr = 1;
PCRE2_FALLTHROUGH /* Fall through */

case OP_PRUNE:
common->verb_offsets = (sljit_u8*)1;
cc += 1;
break;

case OP_THEN_ARG:
common->has_then = TRUE;
common->control_head_ptr = 1;
PCRE2_FALLTHROUGH /* Fall through */

case OP_COMMIT_ARG:
case OP_PRUNE_ARG:
common->verb_offsets = (sljit_u8*)1;
PCRE2_FALLTHROUGH /* Fall through */

case OP_COMMIT_ARG:
case OP_MARK:
set_mark = TRUE;
cc += 1 + 2 + cc[1];
break;

case OP_THEN:
common->has_then = TRUE;
common->control_head_ptr = 1;
cc += 1;
break;

case OP_SKIP:
common->verb_offsets = (sljit_u8*)1;
if (cc < assert_back_end)
common->has_skip_in_assert_back = TRUE;
cc += 1;
break;

case OP_SKIP_ARG:
common->verb_offsets = (sljit_u8*)1;
common->control_head_ptr = 1;
common->has_skip_arg = TRUE;
if (cc < assert_back_end)
Expand Down Expand Up @@ -1434,7 +1445,7 @@ detect_early_fail(compiler_common *common, PCRE2_SPTR cc, int *private_data_star
count = start;
cc += 1 + LINK_SIZE + ((*cc == OP_CBRA) ? IMM2_SIZE : 0);

if (!common->has_then || common->then_offsets[cc - common->start] == 0)
if (common->verb_offsets == NULL || common->verb_offsets[cc - common->start] == 0)
{
while (TRUE)
{
Expand Down Expand Up @@ -3492,31 +3503,25 @@ copy_recurse_data(compiler_common *common, PCRE2_SPTR cc, PCRE2_SPTR ccend, int
delayed_mem_copy_finish(&status);
}

static SLJIT_INLINE void set_then_offsets(compiler_common *common)
static SLJIT_INLINE void set_verb_offsets(compiler_common *common)
{
PCRE2_SPTR cc = common->start;
PCRE2_SPTR end;
PCRE2_SPTR next_top_alternative = cc + GET(cc, 1);
BOOL has_alternatives = TRUE;
sljit_s32 start = 1 + LINK_SIZE;
sljit_s32 last_alternative, end_offset;
sljit_s32 start = 1 + LINK_SIZE, top_start = 1 + LINK_SIZE;
sljit_s32 end_offset;

SLJIT_ASSERT(*cc == OP_BRA);
end = cc;
do
{
last_alternative = (sljit_s32)((end - cc) + 1 + LINK_SIZE);
end += GET(end, 1);
}
while (*end == OP_ALT);
SLJIT_ASSERT(*next_top_alternative == OP_ALT || *next_top_alternative == OP_KET);
cc += 1 + LINK_SIZE;

while (cc < end)
while (*cc != OP_END)
{
if (*cc >= OP_ASSERT && *cc <= OP_SCOND)
{
end_offset = (sljit_s32)((bracketend(cc) - common->start) - (1 + LINK_SIZE));
common->then_offsets[end_offset] = (sljit_u8)has_alternatives;
SLJIT_ASSERT(common->private_data_ptrs[end - common->start] == 0);
common->verb_offsets[end_offset] = (sljit_u8)has_alternatives;
SLJIT_ASSERT(common->private_data_ptrs[end_offset] == 0);
common->private_data_ptrs[end_offset] = start;

has_alternatives = cc[GET(cc, 1)] == OP_ALT;
Expand Down Expand Up @@ -3554,16 +3559,22 @@ static SLJIT_INLINE void set_then_offsets(compiler_common *common)

if (*cc >= OP_KET && *cc <= OP_KETRPOS)
{
has_alternatives = (BOOL)common->then_offsets[cc - common->start];
has_alternatives = (BOOL)common->verb_offsets[cc - common->start];
start = common->private_data_ptrs[cc - common->start];
common->then_offsets[cc - common->start] = 0;
common->verb_offsets[cc - common->start] = 0;
common->private_data_ptrs[cc - common->start] = 0;
cc += 1 + LINK_SIZE;
continue;
}

if (*cc == OP_ALT)
{
if (cc == next_top_alternative) {
next_top_alternative += GET(next_top_alternative, 1);
SLJIT_ASSERT(*next_top_alternative == OP_ALT || *next_top_alternative == OP_KET);
top_start = (sljit_s32)(cc + 1 + LINK_SIZE - common->start);
}

cc += 1 + LINK_SIZE;

if (has_alternatives)
Expand All @@ -3578,9 +3589,21 @@ static SLJIT_INLINE void set_then_offsets(compiler_common *common)
continue;
}

if (*cc >= OP_THEN && *cc <= OP_THEN_ARG && start != 0)
common->then_offsets[start] = (start == last_alternative) + 1;
switch (*cc)
{
case OP_THEN:
case OP_THEN_ARG:
if (start != 0)
common->verb_offsets[start] |= (start == top_start && *next_top_alternative == OP_KET) ? verb_offset_any : verb_offset_then;
break;

case OP_PRUNE:
case OP_PRUNE_ARG:
case OP_SKIP:
case OP_SKIP_ARG:
common->verb_offsets[top_start] |= verb_offset_any;
break;
}
cc = next_opcode(common, cc);
}
}
Expand Down Expand Up @@ -12479,7 +12502,7 @@ compile_matchingpath(compiler_common *common, PCRE2_SPTR cc, PCRE2_SPTR ccend,

SLJIT_ASSERT(*ccend == OP_END || (*ccend >= OP_ALT && *ccend <= OP_KETRPOS));

if (common->has_then && common->then_offsets[cc - common->start] == 1)
if (common->has_then && (common->verb_offsets[cc - common->start] & verb_offset_then) != 0)
{
SLJIT_ASSERT(*ccend != OP_END && common->control_head_ptr != 0);
has_then_trap = TRUE;
Expand Down Expand Up @@ -14671,18 +14694,18 @@ jit_compile(pcre2_code *code, sljit_u32 mode)
common->cbra_ptr = OVECTOR_START + (re->top_bracket + 1) * 2 * sizeof(sljit_sw);
private_data_size = common->cbra_ptr + (re->top_bracket + 1) * sizeof(sljit_sw);

if (common->has_then)
if (common->verb_offsets != NULL)
{
total_length = ccend - common->start;
common->then_offsets = (sljit_u8 *)SLJIT_MALLOC(total_length, allocator_data);
if (!common->then_offsets)
common->verb_offsets = (sljit_u8 *)SLJIT_MALLOC(total_length, allocator_data);
if (!common->verb_offsets)
{
SLJIT_FREE(common->private_data_ptrs, allocator_data);
return PCRE2_ERROR_NOMEMORY;
}

memset(common->then_offsets, 0, total_length);
set_then_offsets(common);
memset(common->verb_offsets, 0, total_length);
set_verb_offsets(common);
}

if ((re->overall_options & PCRE2_ANCHORED) == 0 &&
Expand All @@ -14697,17 +14720,17 @@ jit_compile(pcre2_code *code, sljit_u32 mode)
if (private_data_size > 65536)
{
SLJIT_FREE(common->private_data_ptrs, allocator_data);
if (common->has_then)
SLJIT_FREE(common->then_offsets, allocator_data);
if (common->verb_offsets != NULL)
SLJIT_FREE(common->verb_offsets, allocator_data);
return PCRE2_ERROR_JIT_UNSUPPORTED;
}

compiler = sljit_create_compiler(allocator_data);
if (!compiler)
{
SLJIT_FREE(common->private_data_ptrs, allocator_data);
if (common->has_then)
SLJIT_FREE(common->then_offsets, allocator_data);
if (common->verb_offsets != NULL)
SLJIT_FREE(common->verb_offsets, allocator_data);
return PCRE2_ERROR_NOMEMORY;
}

Expand Down Expand Up @@ -14809,8 +14832,8 @@ jit_compile(pcre2_code *code, sljit_u32 mode)
{
sljit_free_compiler(compiler);
SLJIT_FREE(common->private_data_ptrs, allocator_data);
if (common->has_then)
SLJIT_FREE(common->then_offsets, allocator_data);
if (common->verb_offsets != NULL)
SLJIT_FREE(common->verb_offsets, allocator_data);
PRIV(jit_free_rodata)(common->read_only_data_head, allocator_data);
return PCRE2_ERROR_NOMEMORY;
}
Expand Down Expand Up @@ -14894,8 +14917,8 @@ jit_compile(pcre2_code *code, sljit_u32 mode)
{
sljit_free_compiler(compiler);
SLJIT_FREE(common->private_data_ptrs, allocator_data);
if (common->has_then)
SLJIT_FREE(common->then_offsets, allocator_data);
if (common->verb_offsets != NULL)
SLJIT_FREE(common->verb_offsets, allocator_data);
PRIV(jit_free_rodata)(common->read_only_data_head, allocator_data);
return PCRE2_ERROR_NOMEMORY;
}
Expand Down Expand Up @@ -15013,8 +15036,8 @@ jit_compile(pcre2_code *code, sljit_u32 mode)

sljit_free_compiler(compiler);
SLJIT_FREE(common->private_data_ptrs, allocator_data);
if (common->has_then)
SLJIT_FREE(common->then_offsets, allocator_data);
if (common->verb_offsets != NULL)
SLJIT_FREE(common->verb_offsets, allocator_data);
PRIV(jit_free_rodata)(common->read_only_data_head, allocator_data);
return PCRE2_ERROR_NOMEMORY;
}
Expand Down Expand Up @@ -15182,8 +15205,8 @@ jit_compile(pcre2_code *code, sljit_u32 mode)
#endif /* SUPPORT_UNICODE */

SLJIT_FREE(common->private_data_ptrs, allocator_data);
if (common->has_then)
SLJIT_FREE(common->then_offsets, allocator_data);
if (common->verb_offsets != NULL)
SLJIT_FREE(common->verb_offsets, allocator_data);

executable_func = sljit_generate_code(compiler, 0, NULL);
executable_size = sljit_get_generated_code_size(compiler);
Expand Down
24 changes: 23 additions & 1 deletion testdata/testinput2
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Original file line number Diff line number Diff line change
Expand Up @@ -5527,13 +5527,35 @@ a)"xI
aa
aaaa

/a+?b|a+?(*THEN)/endanchored
/a+?b|a+?(*THEN:arg)/endanchored
aaxaa
aaxaab

/a+?(?:b(*THEN)c|c(*THEN)b)/endanchored
aaabcaaacbaaabc

/a+?(*SKIP)/endanchored
aa
aaaa

/a+?b|a+?(*SKIP:arg)/endanchored
aaxaa
aaxaab

/a+?(?:b(*SKIP)c|c(*SKIP)b)/endanchored
aaabcaaacbaaabc

/a+?(*PRUNE)/endanchored
aa
aaaa

/a+?b|a+?(*PRUNE:arg)/endanchored
aaxaa
aaxaab

/a+?(?:b(*PRUNE)c|c(*PRUNE)b)/endanchored
aaabcaaacbaaabc

# Check auto-anchoring when there is a group that is never obeyed at
# the start of a branch.

Expand Down
34 changes: 33 additions & 1 deletion testdata/testoutput2
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Original file line number Diff line number Diff line change
Expand Up @@ -17168,7 +17168,7 @@ No match
aaaa
0: a

/a+?b|a+?(*THEN)/endanchored
/a+?b|a+?(*THEN:arg)/endanchored
aaxaa
0: a
aaxaab
Expand All @@ -17178,6 +17178,38 @@ No match
aaabcaaacbaaabc
0: aaabc

/a+?(*SKIP)/endanchored
aa
0: a
aaaa
0: a

/a+?b|a+?(*SKIP:arg)/endanchored
aaxaa
0: aa
aaxaab
0: aab

/a+?(?:b(*SKIP)c|c(*SKIP)b)/endanchored
aaabcaaacbaaabc
0: aaabc

/a+?(*PRUNE)/endanchored
aa
0: a
aaaa
0: a

/a+?b|a+?(*PRUNE:arg)/endanchored
aaxaa
0: a
aaxaab
0: aab

/a+?(?:b(*PRUNE)c|c(*PRUNE)b)/endanchored
aaabcaaacbaaabc
0: aaabc

# Check auto-anchoring when there is a group that is never obeyed at
# the start of a branch.

Expand Down
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