Ryan Macnak
e443b89f23
Includes support for modifier spans and duplicate named capture groups. Drops the flow graph implementation to ease maintenance. TEST=corelib/regexp Bug: https://github.com/dart-lang/sdk/issues/56573 Bug: https://github.com/dart-lang/sdk/issues/61337 Bug: https://github.com/dart-lang/sdk/issues/62349 Bug: https://github.com/dart-lang/sdk/issues/62708 Change-Id: I05640ba945a4fa5476e7ad463738f4f39d842c14 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/480121 Reviewed-by: Lasse Nielsen <lrn@google.com> Commit-Queue: Ryan Macnak <rmacnak@google.com>
108 lines
3.0 KiB
C++
108 lines
3.0 KiB
C++
// Copyright 2017 the V8 project authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#ifndef V8_CODEGEN_LABEL_H_
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#define V8_CODEGEN_LABEL_H_
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#include "vm/object.h"
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#include "vm/regexp/base.h"
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namespace dart {
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class V8Label {
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public:
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enum Distance {
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kNear, // near jump: 8 bit displacement (signed)
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kFar // far jump: 32 bit displacement (signed)
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};
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V8Label() = default;
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// Disallow copy construction and assignment, but allow move construction and
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// move assignment on selected platforms (see below).
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V8Label(const V8Label&) = delete;
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V8Label& operator=(const V8Label&) = delete;
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// On ARM64, the Assembler keeps track of pointers to V8Labels to resolve
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// branches to distant targets. Copying labels would confuse the Assembler.
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// On other platforms, allow move construction.
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#if !V8_TARGET_ARCH_ARM64
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// In debug builds, the old V8Label has to be cleared in order to avoid a DCHECK
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// failure in it's destructor.
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#ifdef DEBUG
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V8Label(V8Label&& other) V8_NOEXCEPT { *this = std::move(other); }
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V8Label& operator=(V8Label&& other) V8_NOEXCEPT {
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pos_ = other.pos_;
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near_link_pos_ = other.near_link_pos_;
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other.Unuse();
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other.UnuseNear();
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return *this;
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}
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#else
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V8Label(V8Label&&) V8_NOEXCEPT = default;
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V8Label& operator=(V8Label&&) V8_NOEXCEPT = default;
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#endif
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#endif
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#ifdef DEBUG
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V8_INLINE ~V8Label() {
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DCHECK(!is_linked());
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DCHECK(!is_near_linked());
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}
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#endif
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V8_INLINE void Unuse() { pos_ = 0; }
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V8_INLINE void UnuseNear() { near_link_pos_ = 0; }
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V8_INLINE bool is_bound() const { return pos_ < 0; }
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V8_INLINE bool is_unused() const { return pos_ == 0 && near_link_pos_ == 0; }
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V8_INLINE bool is_linked() const { return pos_ > 0; }
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V8_INLINE bool is_near_linked() const { return near_link_pos_ > 0; }
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// Returns the position of bound or linked labels. Cannot be used
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// for unused labels.
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int pos() const {
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if (pos_ < 0) return -pos_ - 1;
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if (pos_ > 0) return pos_ - 1;
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UNREACHABLE();
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}
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int near_link_pos() const { return near_link_pos_ - 1; }
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private:
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// pos_ encodes both the binding state (via its sign)
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// and the binding position (via its value) of a label.
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//
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// pos_ < 0 bound label, pos() returns the jump target position
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// pos_ == 0 unused label
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// pos_ > 0 linked label, pos() returns the last reference position
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int pos_ = 0;
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// Behaves like |pos_| in the "> 0" case, but for near jumps to this label.
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int near_link_pos_ = 0;
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void bind_to(int pos) {
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pos_ = -pos - 1;
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DCHECK(is_bound());
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}
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void link_to(int pos, Distance distance = kFar) {
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if (distance == kNear) {
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near_link_pos_ = pos + 1;
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DCHECK(is_near_linked());
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} else {
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pos_ = pos + 1;
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DCHECK(is_linked());
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}
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}
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friend class Assembler;
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friend class Displacement;
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friend class RegExpBytecodeGenerator;
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friend class RegExpBytecodeWriter;
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};
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} // namespace dart
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#endif // V8_CODEGEN_LABEL_H_
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