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// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/objects/js-regexp.h"
#include "src/regexp/regexp-error.h"
namespace v8 {
namespace internal {
class RegExpNode;
class RegExpTree;
enum class RegExpCompilationTarget : int { kBytecode, kNative };
// TODO(jgruber): Do not expose in regexp.h.
// TODO(jgruber): Consider splitting between ParseData and CompileData.
struct RegExpCompileData {
// The parsed AST as produced by the RegExpParser.
RegExpTree* tree = nullptr;
// The compiled Node graph as produced by RegExpTree::ToNode methods.
RegExpNode* node = nullptr;
// Either the generated code as produced by the compiler or a trampoline
// to the interpreter.
Handle<Object> code;
// True, iff the pattern is a 'simple' atom with zero captures. In other
// words, the pattern consists of a string with no metacharacters and special
// regexp features, and can be implemented as a standard string search.
bool simple = true;
// True, iff the pattern is anchored at the start of the string with '^'.
bool contains_anchor = false;
// Only use if the pattern contains named captures. If so, this contains a
// mapping of capture names to capture indices.
Handle<FixedArray> capture_name_map;
// The error message. Only used if an error occurred during parsing or
// compilation.
RegExpError error = RegExpError::kNone;
// The position at which the error was detected. Only used if an
// error occurred.
int error_pos = 0;
// The number of capture groups, without the global capture \0.
int capture_count = 0;
// The number of registers used by the generated code.
int register_count = 0;
// The compilation target (bytecode or native code).
RegExpCompilationTarget compilation_target;
class RegExp final : public AllStatic {
// Whether the irregexp engine generates interpreter bytecode.
static bool CanGenerateBytecode() {
return FLAG_regexp_interpret_all || FLAG_regexp_tier_up;
// Parses the RegExp pattern and prepares the JSRegExp object with
// generic data and choice of implementation - as well as what
// the implementation wants to store in the data field.
// Returns false if compilation fails.
V8_WARN_UNUSED_RESULT static MaybeHandle<Object> Compile(
Isolate* isolate, Handle<JSRegExp> re, Handle<String> pattern,
JSRegExp::Flags flags, uint32_t backtrack_limit);
// Ensures that a regexp is fully compiled and ready to be executed on a
// subject string. Returns true on success. Return false on failure, and
// then an exception will be pending.
V8_WARN_UNUSED_RESULT static bool EnsureFullyCompiled(Isolate* isolate,
Handle<JSRegExp> re,
Handle<String> subject);
enum CallOrigin : int {
kFromRuntime = 0,
kFromJs = 1,
// See ECMA-262 section
// This function calls the garbage collector if necessary.
V8_EXPORT_PRIVATE V8_WARN_UNUSED_RESULT static MaybeHandle<Object> Exec(
Isolate* isolate, Handle<JSRegExp> regexp, Handle<String> subject,
int index, Handle<RegExpMatchInfo> last_match_info);
ExperimentalOneshotExec(Isolate* isolate, Handle<JSRegExp> regexp,
Handle<String> subject, int index,
Handle<RegExpMatchInfo> last_match_info);
// Integral return values used throughout regexp code layers.
static constexpr int kInternalRegExpFailure = 0;
static constexpr int kInternalRegExpSuccess = 1;
static constexpr int kInternalRegExpException = -1;
static constexpr int kInternalRegExpRetry = -2;
static constexpr int kInternalRegExpFallbackToExperimental = -3;
static constexpr int kInternalRegExpSmallestResult = -3;
enum IrregexpResult : int32_t {
RE_FAILURE = kInternalRegExpFailure,
RE_SUCCESS = kInternalRegExpSuccess,
RE_EXCEPTION = kInternalRegExpException,
RE_RETRY = kInternalRegExpRetry,
RE_FALLBACK_TO_EXPERIMENTAL = kInternalRegExpFallbackToExperimental,
// Set last match info. If match is nullptr, then setting captures is
// omitted.
static Handle<RegExpMatchInfo> SetLastMatchInfo(
Isolate* isolate, Handle<RegExpMatchInfo> last_match_info,
Handle<String> subject, int capture_count, int32_t* match);
V8_EXPORT_PRIVATE static bool CompileForTesting(Isolate* isolate, Zone* zone,
RegExpCompileData* input,
JSRegExp::Flags flags,
Handle<String> pattern,
Handle<String> sample_subject,
bool is_one_byte);
V8_EXPORT_PRIVATE static void DotPrintForTesting(const char* label,
RegExpNode* node);
static const int kRegExpTooLargeToOptimize = 20 * KB;
static MaybeHandle<Object> ThrowRegExpException(Isolate* isolate,
Handle<JSRegExp> re,
Handle<String> pattern,
RegExpError error);
static void ThrowRegExpException(Isolate* isolate, Handle<JSRegExp> re,
RegExpError error_text);
static bool IsUnmodifiedRegExp(Isolate* isolate, Handle<JSRegExp> regexp);
// Uses a special global mode of irregexp-generated code to perform a global
// search and return multiple results at once. As such, this is essentially an
// iterator over multiple results (retrieved batch-wise in advance).
class RegExpGlobalCache final {
RegExpGlobalCache(Handle<JSRegExp> regexp, Handle<String> subject,
Isolate* isolate);
// Fetch the next entry in the cache for global regexp match results.
// This does not set the last match info. Upon failure, nullptr is
// returned. The cause can be checked with Result(). The previous result is
// still in available in memory when a failure happens.
int32_t* FetchNext();
int32_t* LastSuccessfulMatch();
bool HasException() { return num_matches_ < 0; }
int AdvanceZeroLength(int last_index);
int num_matches_;
int max_matches_;
int current_match_index_;
int registers_per_match_;
// Pointer to the last set of captures.
int32_t* register_array_;
int register_array_size_;
Handle<JSRegExp> regexp_;
Handle<String> subject_;
Isolate* isolate_;
// Caches results for specific regexp queries on the isolate. At the time of
// writing, this is used during global calls to RegExp.prototype.exec and
// @@split.
class RegExpResultsCache final : public AllStatic {
// Attempt to retrieve a cached result. On failure, 0 is returned as a Smi.
// On success, the returned result is guaranteed to be a COW-array.
static Object Lookup(Heap* heap, String key_string, Object key_pattern,
FixedArray* last_match_out, ResultsCacheType type);
// Attempt to add value_array to the cache specified by type. On success,
// value_array is turned into a COW-array.
static void Enter(Isolate* isolate, Handle<String> key_string,
Handle<Object> key_pattern, Handle<FixedArray> value_array,
Handle<FixedArray> last_match_cache, ResultsCacheType type);
static void Clear(FixedArray cache);
static constexpr int kRegExpResultsCacheSize = 0x100;
static constexpr int kStringOffset = 0;
static constexpr int kPatternOffset = 1;
static constexpr int kArrayOffset = 2;
static constexpr int kLastMatchOffset = 3;
static constexpr int kArrayEntriesPerCacheEntry = 4;
} // namespace internal
} // namespace v8
#endif // V8_REGEXP_REGEXP_H_