Replace RE2 import with a dependency

third_party/re2/re2/compile.cc

Index: third_party/re2/re2/compile.cc
diff --git a/third_party/re2/re2/compile.cc b/third_party/re2/re2/compile.cc
deleted file mode 100644
index 50375242e5e26f8acbfb109efd244e3bdc930999..0000000000000000000000000000000000000000
--- a/third_party/re2/re2/compile.cc
+++ /dev/null
@@ -1,1151 +0,0 @@
-// Copyright 2007 The RE2 Authors.  All Rights Reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Compile regular expression to Prog.
-//
-// Prog and Inst are defined in prog.h.
-// This file's external interface is just Regexp::CompileToProg.
-// The Compiler class defined in this file is private.
-
-#include "re2/prog.h"
-#include "re2/re2.h"
-#include "re2/regexp.h"
-#include "re2/walker-inl.h"
-
-namespace re2 {
-
-// List of pointers to Inst* that need to be filled in (patched).
-// Because the Inst* haven't been filled in yet,
-// we can use the Inst* word to hold the list's "next" pointer.
-// It's kind of sleazy, but it works well in practice.
-// See http://swtch.com/~rsc/regexp/regexp1.html for inspiration.
-//
-// Because the out and out1 fields in Inst are no longer pointers,
-// we can't use pointers directly here either.  Instead, p refers
-// to inst_[p>>1].out (p&1 == 0) or inst_[p>>1].out1 (p&1 == 1).
-// p == 0 represents the NULL list.  This is okay because instruction #0
-// is always the fail instruction, which never appears on a list.
-
-struct PatchList {
-  uint32 p;
-
-  // Returns patch list containing just p.
-  static PatchList Mk(uint32 p);
-
-  // Patches all the entries on l to have value v.
-  // Caller must not ever use patch list again.
-  static void Patch(Prog::Inst *inst0, PatchList l, uint32 v);
-
-  // Deref returns the next pointer pointed at by p.
-  static PatchList Deref(Prog::Inst *inst0, PatchList l);
-
-  // Appends two patch lists and returns result.
-  static PatchList Append(Prog::Inst *inst0, PatchList l1, PatchList l2);
-};
-
-static PatchList nullPatchList = { 0 };
-
-// Returns patch list containing just p.
-PatchList PatchList::Mk(uint32 p) {
-  PatchList l;
-  l.p = p;
-  return l;
-}
-
-// Returns the next pointer pointed at by l.
-PatchList PatchList::Deref(Prog::Inst* inst0, PatchList l) {
-  Prog::Inst* ip = &inst0[l.p>>1];
-  if (l.p&1)
-    l.p = ip->out1();
-  else
-    l.p = ip->out();
-  return l;
-}
-
-// Patches all the entries on l to have value v.
-void PatchList::Patch(Prog::Inst *inst0, PatchList l, uint32 val) {
-  while (l.p != 0) {
-    Prog::Inst* ip = &inst0[l.p>>1];
-    if (l.p&1) {
-      l.p = ip->out1();
-      ip->out1_ = val;
-    } else {
-      l.p = ip->out();
-      ip->set_out(val);
-    }
-  }
-}
-
-// Appends two patch lists and returns result.
-PatchList PatchList::Append(Prog::Inst* inst0, PatchList l1, PatchList l2) {
-  if (l1.p == 0)
-    return l2;
-  if (l2.p == 0)
-    return l1;
-
-  PatchList l = l1;
-  for (;;) {
-    PatchList next = PatchList::Deref(inst0, l);
-    if (next.p == 0)
-      break;
-    l = next;
-  }
-
-  Prog::Inst* ip = &inst0[l.p>>1];
-  if (l.p&1)
-    ip->out1_ = l2.p;
-  else
-    ip->set_out(l2.p);
-
-  return l1;
-}
-
-// Compiled program fragment.
-struct Frag {
-  uint32 begin;
-  PatchList end;
-
-  Frag() : begin(0) { end.p = 0; }  // needed so Frag can go in vector
-  Frag(uint32 begin, PatchList end) : begin(begin), end(end) {}
-};
-
-// Input encodings.
-enum Encoding {
-  kEncodingUTF8 = 1,  // UTF-8 (0-10FFFF)
-  kEncodingLatin1,    // Latin1 (0-FF)
-};
-
-class Compiler : public Regexp::Walker<Frag> {
- public:
-  explicit Compiler();
-  ~Compiler();
-
-  // Compiles Regexp to a new Prog.
-  // Caller is responsible for deleting Prog when finished with it.
-  // If reversed is true, compiles for walking over the input
-  // string backward (reverses all concatenations).
-  static Prog *Compile(Regexp* re, bool reversed, int64 max_mem);
-
-  // Compiles alternation of all the re to a new Prog.
-  // Each re has a match with an id equal to its index in the vector.
-  static Prog* CompileSet(const RE2::Options& options, RE2::Anchor anchor,
-                          Regexp* re);
-
-  // Interface for Regexp::Walker, which helps traverse the Regexp.
-  // The walk is purely post-recursive: given the machines for the
-  // children, PostVisit combines them to create the machine for
-  // the current node.  The child_args are Frags.
-  // The Compiler traverses the Regexp parse tree, visiting
-  // each node in depth-first order.  It invokes PreVisit before
-  // visiting the node's children and PostVisit after visiting
-  // the children.
-  Frag PreVisit(Regexp* re, Frag parent_arg, bool* stop);
-  Frag PostVisit(Regexp* re, Frag parent_arg, Frag pre_arg, Frag* child_args,
-                 int nchild_args);
-  Frag ShortVisit(Regexp* re, Frag parent_arg);
-  Frag Copy(Frag arg);
-
-  // Given fragment a, returns a+ or a+?; a* or a*?; a? or a??
-  Frag Plus(Frag a, bool nongreedy);
-  Frag Star(Frag a, bool nongreedy);
-  Frag Quest(Frag a, bool nongreedy);
-
-  // Given fragment a, returns (a) capturing as \n.
-  Frag Capture(Frag a, int n);
-
-  // Given fragments a and b, returns ab; a|b
-  Frag Cat(Frag a, Frag b);
-  Frag Alt(Frag a, Frag b);
-
-  // Returns a fragment that can't match anything.
-  Frag NoMatch();
-
-  // Returns a fragment that matches the empty string.
-  Frag Match(int32 id);
-
-  // Returns a no-op fragment.
-  Frag Nop();
-
-  // Returns a fragment matching the byte range lo-hi.
-  Frag ByteRange(int lo, int hi, bool foldcase);
-
-  // Returns a fragment matching an empty-width special op.
-  Frag EmptyWidth(EmptyOp op);
-
-  // Adds n instructions to the program.
-  // Returns the index of the first one.
-  // Returns -1 if no more instructions are available.
-  int AllocInst(int n);
-
-  // Deletes unused instructions.
-  void Trim();
-
-  // Rune range compiler.
-
-  // Begins a new alternation.
-  void BeginRange();
-
-  // Adds a fragment matching the rune range lo-hi.
-  void AddRuneRange(Rune lo, Rune hi, bool foldcase);
-  void AddRuneRangeLatin1(Rune lo, Rune hi, bool foldcase);
-  void AddRuneRangeUTF8(Rune lo, Rune hi, bool foldcase);
-  void Add_80_10ffff();
-
-  // New suffix that matches the byte range lo-hi, then goes to next.
-  int RuneByteSuffix(uint8 lo, uint8 hi, bool foldcase, int next);
-  int UncachedRuneByteSuffix(uint8 lo, uint8 hi, bool foldcase, int next);
-
-  // Adds a suffix to alternation.
-  void AddSuffix(int id);
-
-  // Returns the alternation of all the added suffixes.
-  Frag EndRange();
-
-  // Single rune.
-  Frag Literal(Rune r, bool foldcase);
-
-  void Setup(Regexp::ParseFlags, int64, RE2::Anchor);
-  Prog* Finish();
-
-  // Returns .* where dot = any byte
-  Frag DotStar();
-
- private:
-  Prog* prog_;         // Program being built.
-  bool failed_;        // Did we give up compiling?
-  Encoding encoding_;  // Input encoding
-  bool reversed_;      // Should program run backward over text?
-
-  int max_inst_;       // Maximum number of instructions.
-
-  Prog::Inst* inst_;   // Pointer to first instruction.
-  int inst_len_;       // Number of instructions used.
-  int inst_cap_;       // Number of instructions allocated.
-
-  int64 max_mem_;      // Total memory budget.
-
-  map<uint64, int> rune_cache_;
-  Frag rune_range_;
-
-  RE2::Anchor anchor_;  // anchor mode for RE2::Set
-
-  DISALLOW_COPY_AND_ASSIGN(Compiler);
-};
-
-Compiler::Compiler() {
-  prog_ = new Prog();
-  failed_ = false;
-  encoding_ = kEncodingUTF8;
-  reversed_ = false;
-  inst_ = NULL;
-  inst_len_ = 0;
-  inst_cap_ = 0;
-  max_inst_ = 1;  // make AllocInst for fail instruction okay
-  max_mem_ = 0;
-  int fail = AllocInst(1);
-  inst_[fail].InitFail();
-  max_inst_ = 0;  // Caller must change
-}
-
-Compiler::~Compiler() {
-  delete prog_;
-  delete[] inst_;
-}
-
-int Compiler::AllocInst(int n) {
-  if (failed_ || inst_len_ + n > max_inst_) {
-    failed_ = true;
-    return -1;
-  }
-
-  if (inst_len_ + n > inst_cap_) {
-    if (inst_cap_ == 0)
-      inst_cap_ = 8;
-    while (inst_len_ + n > inst_cap_)
-      inst_cap_ *= 2;
-    Prog::Inst* ip = new Prog::Inst[inst_cap_];
-    memmove(ip, inst_, inst_len_ * sizeof ip[0]);
-    memset(ip + inst_len_, 0, (inst_cap_ - inst_len_) * sizeof ip[0]);
-    delete[] inst_;
-    inst_ = ip;
-  }
-  int id = inst_len_;
-  inst_len_ += n;
-  return id;
-}
-
-void Compiler::Trim() {
-  if (inst_len_ < inst_cap_) {
-    Prog::Inst* ip = new Prog::Inst[inst_len_];
-    memmove(ip, inst_, inst_len_ * sizeof ip[0]);
-    delete[] inst_;
-    inst_ = ip;
-    inst_cap_ = inst_len_;
-  }
-}
-
-// These routines are somewhat hard to visualize in text --
-// see http://swtch.com/~rsc/regexp/regexp1.html for
-// pictures explaining what is going on here.
-
-// Returns an unmatchable fragment.
-Frag Compiler::NoMatch() {
-  return Frag(0, nullPatchList);
-}
-
-// Is a an unmatchable fragment?
-static bool IsNoMatch(Frag a) {
-  return a.begin == 0;
-}
-
-// Given fragments a and b, returns fragment for ab.
-Frag Compiler::Cat(Frag a, Frag b) {
-  if (IsNoMatch(a) || IsNoMatch(b))
-    return NoMatch();
-
-  // Elide no-op.
-  Prog::Inst* begin = &inst_[a.begin];
-  if (begin->opcode() == kInstNop &&
-      a.end.p == (a.begin << 1) &&
-      begin->out() == 0) {
-    PatchList::Patch(inst_, a.end, b.begin);  // in case refs to a somewhere
-    return b;
-  }
-
-  // To run backward over string, reverse all concatenations.
-  if (reversed_) {
-    PatchList::Patch(inst_, b.end, a.begin);
-    return Frag(b.begin, a.end);
-  }
-
-  PatchList::Patch(inst_, a.end, b.begin);
-  return Frag(a.begin, b.end);
-}
-
-// Given fragments for a and b, returns fragment for a|b.
-Frag Compiler::Alt(Frag a, Frag b) {
-  // Special case for convenience in loops.
-  if (IsNoMatch(a))
-    return b;
-  if (IsNoMatch(b))
-    return a;
-
-  int id = AllocInst(1);
-  if (id < 0)
-    return NoMatch();
-
-  inst_[id].InitAlt(a.begin, b.begin);
-  return Frag(id, PatchList::Append(inst_, a.end, b.end));
-}
-
-// When capturing submatches in like-Perl mode, a kOpAlt Inst
-// treats out_ as the first choice, out1_ as the second.
-//
-// For *, +, and ?, if out_ causes another repetition,
-// then the operator is greedy.  If out1_ is the repetition
-// (and out_ moves forward), then the operator is non-greedy.
-
-// Given a fragment a, returns a fragment for a* or a*? (if nongreedy)
-Frag Compiler::Star(Frag a, bool nongreedy) {
-  int id = AllocInst(1);
-  if (id < 0)
-    return NoMatch();
-  inst_[id].InitAlt(0, 0);
-  PatchList::Patch(inst_, a.end, id);
-  if (nongreedy) {
-    inst_[id].out1_ = a.begin;
-    return Frag(id, PatchList::Mk(id << 1));
-  } else {
-    inst_[id].set_out(a.begin);
-    return Frag(id, PatchList::Mk((id << 1) | 1));
-  }
-}
-
-// Given a fragment for a, returns a fragment for a+ or a+? (if nongreedy)
-Frag Compiler::Plus(Frag a, bool nongreedy) {
-  // a+ is just a* with a different entry point.
-  Frag f = Star(a, nongreedy);
-  return Frag(a.begin, f.end);
-}
-
-// Given a fragment for a, returns a fragment for a? or a?? (if nongreedy)
-Frag Compiler::Quest(Frag a, bool nongreedy) {
-  if (IsNoMatch(a))
-    return Nop();
-  int id = AllocInst(1);
-  if (id < 0)
-    return NoMatch();
-  PatchList pl;
-  if (nongreedy) {
-    inst_[id].InitAlt(0, a.begin);
-    pl = PatchList::Mk(id << 1);
-  } else {
-    inst_[id].InitAlt(a.begin, 0);
-    pl = PatchList::Mk((id << 1) | 1);
-  }
-  return Frag(id, PatchList::Append(inst_, pl, a.end));
-}
-
-// Returns a fragment for the byte range lo-hi.
-Frag Compiler::ByteRange(int lo, int hi, bool foldcase) {
-  int id = AllocInst(1);
-  if (id < 0)
-    return NoMatch();
-  inst_[id].InitByteRange(lo, hi, foldcase, 0);
-  prog_->byte_inst_count_++;
-  prog_->MarkByteRange(lo, hi);
-  if (foldcase && lo <= 'z' && hi >= 'a') {
-    if (lo < 'a')
-      lo = 'a';
-    if (hi > 'z')
-      hi = 'z';
-    if (lo <= hi)
-      prog_->MarkByteRange(lo + 'A' - 'a', hi + 'A' - 'a');
-  }
-  return Frag(id, PatchList::Mk(id << 1));
-}
-
-// Returns a no-op fragment.  Sometimes unavoidable.
-Frag Compiler::Nop() {
-  int id = AllocInst(1);
-  if (id < 0)
-    return NoMatch();
-  inst_[id].InitNop(0);
-  return Frag(id, PatchList::Mk(id << 1));
-}
-
-// Returns a fragment that signals a match.
-Frag Compiler::Match(int32 match_id) {
-  int id = AllocInst(1);
-  if (id < 0)
-    return NoMatch();
-  inst_[id].InitMatch(match_id);
-  return Frag(id, nullPatchList);
-}
-
-// Returns a fragment matching a particular empty-width op (like ^ or $)
-Frag Compiler::EmptyWidth(EmptyOp empty) {
-  int id = AllocInst(1);
-  if (id < 0)
-    return NoMatch();
-  inst_[id].InitEmptyWidth(empty, 0);
-  if (empty & (kEmptyBeginLine|kEmptyEndLine))
-    prog_->MarkByteRange('\n', '\n');
-  if (empty & (kEmptyWordBoundary|kEmptyNonWordBoundary)) {
-    int j;
-    for (int i = 0; i < 256; i = j) {
-      for (j = i + 1; j < 256 &&
-                      Prog::IsWordChar(static_cast<uint8>(i)) ==
-                          Prog::IsWordChar(static_cast<uint8>(j));
-           j++)
-        ;
-      prog_->MarkByteRange(i, j-1);
-    }
-  }
-  return Frag(id, PatchList::Mk(id << 1));
-}
-
-// Given a fragment a, returns a fragment with capturing parens around a.
-Frag Compiler::Capture(Frag a, int n) {
-  if (IsNoMatch(a))
-    return NoMatch();
-  int id = AllocInst(2);
-  if (id < 0)
-    return NoMatch();
-  inst_[id].InitCapture(2*n, a.begin);
-  inst_[id+1].InitCapture(2*n+1, 0);
-  PatchList::Patch(inst_, a.end, id+1);
-
-  return Frag(id, PatchList::Mk((id+1) << 1));
-}
-
-// A Rune is a name for a Unicode code point.
-// Returns maximum rune encoded by UTF-8 sequence of length len.
-static int MaxRune(int len) {
-  int b;  // number of Rune bits in len-byte UTF-8 sequence (len < UTFmax)
-  if (len == 1)
-    b = 7;
-  else
-    b = 8-(len+1) + 6*(len-1);
-  return (1<<b) - 1;   // maximum Rune for b bits.
-}
-
-// The rune range compiler caches common suffix fragments,
-// which are very common in UTF-8 (e.g., [80-bf]).
-// The fragment suffixes are identified by their start
-// instructions.  NULL denotes the eventual end match.
-// The Frag accumulates in rune_range_.  Caching common
-// suffixes reduces the UTF-8 "." from 32 to 24 instructions,
-// and it reduces the corresponding one-pass NFA from 16 nodes to 8.
-
-void Compiler::BeginRange() {
-  rune_cache_.clear();
-  rune_range_.begin = 0;
-  rune_range_.end = nullPatchList;
-}
-
-int Compiler::UncachedRuneByteSuffix(uint8 lo, uint8 hi, bool foldcase,
-                                     int next) {
-  Frag f = ByteRange(lo, hi, foldcase);
-  if (next != 0) {
-    PatchList::Patch(inst_, f.end, next);
-  } else {
-    rune_range_.end = PatchList::Append(inst_, rune_range_.end, f.end);
-  }
-  return f.begin;
-}
-
-int Compiler::RuneByteSuffix(uint8 lo, uint8 hi, bool foldcase, int next) {
-  // In Latin1 mode, there's no point in caching.
-  // In forward UTF-8 mode, only need to cache continuation bytes.
-  if (encoding_ == kEncodingLatin1 ||
-      (encoding_ == kEncodingUTF8 &&
-       !reversed_ &&
-       !(0x80 <= lo && hi <= 0xbf))) {
-    return UncachedRuneByteSuffix(lo, hi, foldcase, next);
-  }
-
-  uint64 key = (uint64)next << 17 |
-               (uint64)lo   <<  9 |
-               (uint64)hi   <<  1 |
-               (uint64)foldcase;
-  map<uint64, int>::iterator it = rune_cache_.find(key);
-  if (it != rune_cache_.end())
-    return it->second;
-  int id = UncachedRuneByteSuffix(lo, hi, foldcase, next);
-  rune_cache_[key] = id;
-  return id;
-}
-
-void Compiler::AddSuffix(int id) {
-  if (rune_range_.begin == 0) {
-    rune_range_.begin = id;
-    return;
-  }
-
-  int alt = AllocInst(1);
-  if (alt < 0) {
-    rune_range_.begin = 0;
-    return;
-  }
-  inst_[alt].InitAlt(rune_range_.begin, id);
-  rune_range_.begin = alt;
-}
-
-Frag Compiler::EndRange() {
-  return rune_range_;
-}
-
-// Converts rune range lo-hi into a fragment that recognizes
-// the bytes that would make up those runes in the current
-// encoding (Latin 1 or UTF-8).
-// This lets the machine work byte-by-byte even when
-// using multibyte encodings.
-
-void Compiler::AddRuneRange(Rune lo, Rune hi, bool foldcase) {
-  switch (encoding_) {
-    default:
-    case kEncodingUTF8:
-      AddRuneRangeUTF8(lo, hi, foldcase);
-      break;
-    case kEncodingLatin1:
-      AddRuneRangeLatin1(lo, hi, foldcase);
-      break;
-  }
-}
-
-void Compiler::AddRuneRangeLatin1(Rune lo, Rune hi, bool foldcase) {
-  // Latin1 is easy: runes *are* bytes.
-  if (lo > hi || lo > 0xFF)
-    return;
-  if (hi > 0xFF)
-    hi = 0xFF;
-  AddSuffix(RuneByteSuffix(static_cast<uint8>(lo), static_cast<uint8>(hi),
-                           foldcase, 0));
-}
-
-// Table describing how to make a UTF-8 matching machine
-// for the rune range 80-10FFFF (Runeself-Runemax).
-// This range happens frequently enough (for example /./ and /[^a-z]/)
-// and the rune_cache_ map is slow enough that this is worth
-// special handling.  Makes compilation of a small expression
-// with a dot in it about 10% faster.
-// The * in the comments below mark whole sequences.
-static struct ByteRangeProg {
-  int next;
-  int lo;
-  int hi;
-} prog_80_10ffff[] = {
-  // Two-byte
-  { -1, 0x80, 0xBF, },  // 0:  80-BF
-  {  0, 0xC2, 0xDF, },  // 1:  C2-DF 80-BF*
-
-  // Three-byte
-  {  0, 0xA0, 0xBF, },  // 2:  A0-BF 80-BF
-  {  2, 0xE0, 0xE0, },  // 3:  E0 A0-BF 80-BF*
-  {  0, 0x80, 0xBF, },  // 4:  80-BF 80-BF
-  {  4, 0xE1, 0xEF, },  // 5:  E1-EF 80-BF 80-BF*
-
-  // Four-byte
-  {  4, 0x90, 0xBF, },  // 6:  90-BF 80-BF 80-BF
-  {  6, 0xF0, 0xF0, },  // 7:  F0 90-BF 80-BF 80-BF*
-  {  4, 0x80, 0xBF, },  // 8:  80-BF 80-BF 80-BF
-  {  8, 0xF1, 0xF3, },  // 9: F1-F3 80-BF 80-BF 80-BF*
-  {  4, 0x80, 0x8F, },  // 10: 80-8F 80-BF 80-BF
-  { 10, 0xF4, 0xF4, },  // 11: F4 80-8F 80-BF 80-BF*
-};
-
-void Compiler::Add_80_10ffff() {
-  int inst[arraysize(prog_80_10ffff)] = { 0 }; // does not need to be initialized; silences gcc warning
-  for (int i = 0; i < arraysize(prog_80_10ffff); i++) {
-    const ByteRangeProg& p = prog_80_10ffff[i];
-    int next = 0;
-    if (p.next >= 0)
-      next = inst[p.next];
-    inst[i] = UncachedRuneByteSuffix(static_cast<uint8>(p.lo),
-                                     static_cast<uint8>(p.hi), false, next);
-    if ((p.lo & 0xC0) != 0x80)
-      AddSuffix(inst[i]);
-  }
-}
-
-void Compiler::AddRuneRangeUTF8(Rune lo, Rune hi, bool foldcase) {
-  if (lo > hi)
-    return;
-
-  // Pick off 80-10FFFF as a common special case
-  // that can bypass the slow rune_cache_.
-  if (lo == 0x80 && hi == 0x10ffff && !reversed_) {
-    Add_80_10ffff();
-    return;
-  }
-
-  // Split range into same-length sized ranges.
-  for (int i = 1; i < UTFmax; i++) {
-    Rune max = MaxRune(i);
-    if (lo <= max && max < hi) {
-      AddRuneRangeUTF8(lo, max, foldcase);
-      AddRuneRangeUTF8(max+1, hi, foldcase);
-      return;
-    }
-  }
-
-  // ASCII range is always a special case.
-  if (hi < Runeself) {
-    AddSuffix(RuneByteSuffix(static_cast<uint8>(lo), static_cast<uint8>(hi),
-                             foldcase, 0));
-    return;
-  }
-
-  // Split range into sections that agree on leading bytes.
-  for (int i = 1; i < UTFmax; i++) {
-    uint m = (1<<(6*i)) - 1;  // last i bytes of a UTF-8 sequence
-    if ((lo & ~m) != (hi & ~m)) {
-      if ((lo & m) != 0) {
-        AddRuneRangeUTF8(lo, lo|m, foldcase);
-        AddRuneRangeUTF8((lo|m)+1, hi, foldcase);
-        return;
-      }
-      if ((hi & m) != m) {
-        AddRuneRangeUTF8(lo, (hi&~m)-1, foldcase);
-        AddRuneRangeUTF8(hi&~m, hi, foldcase);
-        return;
-      }
-    }
-  }
-
-  // Finally.  Generate byte matching equivalent for lo-hi.
-  uint8 ulo[UTFmax], uhi[UTFmax];
-  int n = runetochar(reinterpret_cast<char*>(ulo), &lo);
-  int m = runetochar(reinterpret_cast<char*>(uhi), &hi);
-  (void)m;  // USED(m)
-  DCHECK_EQ(n, m);
-
-  int id = 0;
-  if (reversed_) {
-    for (int i = 0; i < n; i++)
-      id = RuneByteSuffix(ulo[i], uhi[i], false, id);
-  } else {
-    for (int i = n-1; i >= 0; i--)
-      id = RuneByteSuffix(ulo[i], uhi[i], false, id);
-  }
-  AddSuffix(id);
-}
-
-// Should not be called.
-Frag Compiler::Copy(Frag arg) {
-  // We're using WalkExponential; there should be no copying.
-  LOG(DFATAL) << "Compiler::Copy called!";
-  failed_ = true;
-  return NoMatch();
-}
-
-// Visits a node quickly; called once WalkExponential has
-// decided to cut this walk short.
-Frag Compiler::ShortVisit(Regexp* re, Frag) {
-  failed_ = true;
-  return NoMatch();
-}
-
-// Called before traversing a node's children during the walk.
-Frag Compiler::PreVisit(Regexp* re, Frag, bool* stop) {
-  // Cut off walk if we've already failed.
-  if (failed_)
-    *stop = true;
-
-  return Frag();  // not used by caller
-}
-
-Frag Compiler::Literal(Rune r, bool foldcase) {
-  switch (encoding_) {
-    default:
-      return Frag();
-
-    case kEncodingLatin1:
-      return ByteRange(r, r, foldcase);
-
-    case kEncodingUTF8: {
-      if (r < Runeself)  // Make common case fast.
-        return ByteRange(r, r, foldcase);
-      uint8 buf[UTFmax];
-      int n = runetochar(reinterpret_cast<char*>(buf), &r);
-      Frag f = ByteRange((uint8)buf[0], buf[0], false);
-      for (int i = 1; i < n; i++)
-        f = Cat(f, ByteRange((uint8)buf[i], buf[i], false));
-      return f;
-    }
-  }
-}
-
-// Called after traversing the node's children during the walk.
-// Given their frags, build and return the frag for this re.
-Frag Compiler::PostVisit(Regexp* re, Frag, Frag, Frag* child_frags,
-                         int nchild_frags) {
-  // If a child failed, don't bother going forward, especially
-  // since the child_frags might contain Frags with NULLs in them.
-  if (failed_)
-    return NoMatch();
-
-  // Given the child fragments, return the fragment for this node.
-  switch (re->op()) {
-    case kRegexpRepeat:
-      // Should not see; code at bottom of function will print error
-      break;
-
-    case kRegexpNoMatch:
-      return NoMatch();
-
-    case kRegexpEmptyMatch:
-      return Nop();
-
-    case kRegexpHaveMatch: {
-      Frag f = Match(re->match_id());
-      // Remember unanchored match to end of string.
-      if (anchor_ != RE2::ANCHOR_BOTH)
-        f = Cat(DotStar(), Cat(EmptyWidth(kEmptyEndText), f));
-      return f;
-    }
-
-    case kRegexpConcat: {
-      Frag f = child_frags[0];
-      for (int i = 1; i < nchild_frags; i++)
-        f = Cat(f, child_frags[i]);
-      return f;
-    }
-
-    case kRegexpAlternate: {
-      Frag f = child_frags[0];
-      for (int i = 1; i < nchild_frags; i++)
-        f = Alt(f, child_frags[i]);
-      return f;
-    }
-
-    case kRegexpStar:
-      return Star(child_frags[0], (re->parse_flags()&Regexp::NonGreedy) != 0);
-
-    case kRegexpPlus:
-      return Plus(child_frags[0], (re->parse_flags()&Regexp::NonGreedy) != 0);
-
-    case kRegexpQuest:
-      return Quest(child_frags[0], (re->parse_flags()&Regexp::NonGreedy) != 0);
-
-    case kRegexpLiteral:
-      return Literal(re->rune(), (re->parse_flags()&Regexp::FoldCase) != 0);
-
-    case kRegexpLiteralString: {
-      // Concatenation of literals.
-      if (re->nrunes() == 0)
-        return Nop();
-      Frag f;
-      for (int i = 0; i < re->nrunes(); i++) {
-        Frag f1 = Literal(re->runes()[i],
-                          (re->parse_flags()&Regexp::FoldCase) != 0);
-        if (i == 0)
-          f = f1;
-        else
-          f = Cat(f, f1);
-      }
-      return f;
-    }
-
-    case kRegexpAnyChar:
-      BeginRange();
-      AddRuneRange(0, Runemax, false);
-      return EndRange();
-
-    case kRegexpAnyByte:
-      return ByteRange(0x00, 0xFF, false);
-
-    case kRegexpCharClass: {
-      CharClass* cc = re->cc();
-      if (cc->empty()) {
-        // This can't happen.
-        LOG(DFATAL) << "No ranges in char class";
-        failed_ = true;
-        return NoMatch();
-      }
-
-      // ASCII case-folding optimization: if the char class
-      // behaves the same on A-Z as it does on a-z,
-      // discard any ranges wholly contained in A-Z
-      // and mark the other ranges as foldascii.
-      // This reduces the size of a program for
-      // (?i)abc from 3 insts per letter to 1 per letter.
-      bool foldascii = cc->FoldsASCII();
-
-      // Character class is just a big OR of the different
-      // character ranges in the class.
-      BeginRange();
-      for (CharClass::iterator i = cc->begin(); i != cc->end(); ++i) {
-        // ASCII case-folding optimization (see above).
-        if (foldascii && 'A' <= i->lo && i->hi <= 'Z')
-          continue;
-
-        // If this range contains all of A-Za-z or none of it,
-        // the fold flag is unnecessary; don't bother.
-        bool fold = foldascii;
-        if ((i->lo <= 'A' && 'z' <= i->hi) || i->hi < 'A' || 'z' < i->lo ||
-            ('Z' < i->lo && i->hi < 'a'))
-          fold = false;
-
-        AddRuneRange(i->lo, i->hi, fold);
-      }
-      return EndRange();
-    }
-
-    case kRegexpCapture:
-      // If this is a non-capturing parenthesis -- (?:foo) --
-      // just use the inner expression.
-      if (re->cap() < 0)
-        return child_frags[0];
-      return Capture(child_frags[0], re->cap());
-
-    case kRegexpBeginLine:
-      return EmptyWidth(reversed_ ? kEmptyEndLine : kEmptyBeginLine);
-
-    case kRegexpEndLine:
-      return EmptyWidth(reversed_ ? kEmptyBeginLine : kEmptyEndLine);
-
-    case kRegexpBeginText:
-      return EmptyWidth(reversed_ ? kEmptyEndText : kEmptyBeginText);
-
-    case kRegexpEndText:
-      return EmptyWidth(reversed_ ? kEmptyBeginText : kEmptyEndText);
-
-    case kRegexpWordBoundary:
-      return EmptyWidth(kEmptyWordBoundary);
-
-    case kRegexpNoWordBoundary:
-      return EmptyWidth(kEmptyNonWordBoundary);
-  }
-  LOG(DFATAL) << "Missing case in Compiler: " << re->op();
-  failed_ = true;
-  return NoMatch();
-}
-
-// Is this regexp required to start at the beginning of the text?
-// Only approximate; can return false for complicated regexps like (\Aa|\Ab),
-// but handles (\A(a|b)).  Could use the Walker to write a more exact one.
-static bool IsAnchorStart(Regexp** pre, int depth) {
-  Regexp* re = *pre;
-  Regexp* sub;
-  // The depth limit makes sure that we don't overflow
-  // the stack on a deeply nested regexp.  As the comment
-  // above says, IsAnchorStart is conservative, so returning
-  // a false negative is okay.  The exact limit is somewhat arbitrary.
-  if (re == NULL || depth >= 4)
-    return false;
-  switch (re->op()) {
-    default:
-      break;
-    case kRegexpConcat:
-      if (re->nsub() > 0) {
-        sub = re->sub()[0]->Incref();
-        if (IsAnchorStart(&sub, depth+1)) {
-          Regexp** subcopy = new Regexp*[re->nsub()];
-          subcopy[0] = sub;  // already have reference
-          for (int i = 1; i < re->nsub(); i++)
-            subcopy[i] = re->sub()[i]->Incref();
-          *pre = Regexp::Concat(subcopy, re->nsub(), re->parse_flags());
-          delete[] subcopy;
-          re->Decref();
-          return true;
-        }
-        sub->Decref();
-      }
-      break;
-    case kRegexpCapture:
-      sub = re->sub()[0]->Incref();
-      if (IsAnchorStart(&sub, depth+1)) {
-        *pre = Regexp::Capture(sub, re->parse_flags(), re->cap());
-        re->Decref();
-        return true;
-      }
-      sub->Decref();
-      break;
-    case kRegexpBeginText:
-      *pre = Regexp::LiteralString(NULL, 0, re->parse_flags());
-      re->Decref();
-      return true;
-  }
-  return false;
-}
-
-// Is this regexp required to start at the end of the text?
-// Only approximate; can return false for complicated regexps like (a\z|b\z),
-// but handles ((a|b)\z).  Could use the Walker to write a more exact one.
-static bool IsAnchorEnd(Regexp** pre, int depth) {
-  Regexp* re = *pre;
-  Regexp* sub;
-  // The depth limit makes sure that we don't overflow
-  // the stack on a deeply nested regexp.  As the comment
-  // above says, IsAnchorEnd is conservative, so returning
-  // a false negative is okay.  The exact limit is somewhat arbitrary.
-  if (re == NULL || depth >= 4)
-    return false;
-  switch (re->op()) {
-    default:
-      break;
-    case kRegexpConcat:
-      if (re->nsub() > 0) {
-        sub = re->sub()[re->nsub() - 1]->Incref();
-        if (IsAnchorEnd(&sub, depth+1)) {
-          Regexp** subcopy = new Regexp*[re->nsub()];
-          subcopy[re->nsub() - 1] = sub;  // already have reference
-          for (int i = 0; i < re->nsub() - 1; i++)
-            subcopy[i] = re->sub()[i]->Incref();
-          *pre = Regexp::Concat(subcopy, re->nsub(), re->parse_flags());
-          delete[] subcopy;
-          re->Decref();
-          return true;
-        }
-        sub->Decref();
-      }
-      break;
-    case kRegexpCapture:
-      sub = re->sub()[0]->Incref();
-      if (IsAnchorEnd(&sub, depth+1)) {
-        *pre = Regexp::Capture(sub, re->parse_flags(), re->cap());
-        re->Decref();
-        return true;
-      }
-      sub->Decref();
-      break;
-    case kRegexpEndText:
-      *pre = Regexp::LiteralString(NULL, 0, re->parse_flags());
-      re->Decref();
-      return true;
-  }
-  return false;
-}
-
-void Compiler::Setup(Regexp::ParseFlags flags, int64 max_mem,
-                     RE2::Anchor anchor) {
-  prog_->set_flags(flags);
-
-  if (flags & Regexp::Latin1)
-    encoding_ = kEncodingLatin1;
-  max_mem_ = max_mem;
-  if (max_mem <= 0) {
-    max_inst_ = 100000;  // more than enough
-  } else if (max_mem <= static_cast<int64>(sizeof(Prog))) {
-    // No room for anything.
-    max_inst_ = 0;
-  } else {
-    int64 m = (max_mem - sizeof(Prog)) / sizeof(Prog::Inst);
-    // Limit instruction count so that inst->id() fits nicely in an int.
-    // SparseArray also assumes that the indices (inst->id()) are ints.
-    // The call to WalkExponential uses 2*max_inst_ below,
-    // and other places in the code use 2 or 3 * prog->size().
-    // Limiting to 2^24 should avoid overflow in those places.
-    // (The point of allowing more than 32 bits of memory is to
-    // have plenty of room for the DFA states, not to use it up
-    // on the program.)
-    if (m >= 1<<24)
-      m = 1<<24;
-
-    // Inst imposes its own limit (currently bigger than 2^24 but be safe).
-    if (m > Prog::Inst::kMaxInst)
-      m = Prog::Inst::kMaxInst;
-
-    max_inst_ = static_cast<int>(m);
-  }
-
-  anchor_ = anchor;
-}
-
-// Compiles re, returning program.
-// Caller is responsible for deleting prog_.
-// If reversed is true, compiles a program that expects
-// to run over the input string backward (reverses all concatenations).
-// The reversed flag is also recorded in the returned program.
-Prog* Compiler::Compile(Regexp* re, bool reversed, int64 max_mem) {
-  Compiler c;
-
-  c.Setup(re->parse_flags(), max_mem, RE2::ANCHOR_BOTH /* unused */);
-  c.reversed_ = reversed;
-
-  // Simplify to remove things like counted repetitions
-  // and character classes like \d.
-  Regexp* sre = re->Simplify();
-  if (sre == NULL)
-    return NULL;
-
-  // Record whether prog is anchored, removing the anchors.
-  // (They get in the way of other optimizations.)
-  bool is_anchor_start = IsAnchorStart(&sre, 0);
-  bool is_anchor_end = IsAnchorEnd(&sre, 0);
-
-  // Generate fragment for entire regexp.
-  Frag f = c.WalkExponential(sre, Frag(), 2*c.max_inst_);
-  sre->Decref();
-  if (c.failed_)
-    return NULL;
-
-  // Success!  Finish by putting Match node at end, and record start.
-  // Turn off c.reversed_ (if it is set) to force the remaining concatenations
-  // to behave normally.
-  c.reversed_ = false;
-  Frag all = c.Cat(f, c.Match(0));
-  c.prog_->set_start(all.begin);
-
-  if (reversed) {
-    c.prog_->set_anchor_start(is_anchor_end);
-    c.prog_->set_anchor_end(is_anchor_start);
-  } else {
-    c.prog_->set_anchor_start(is_anchor_start);
-    c.prog_->set_anchor_end(is_anchor_end);
-  }
-
-  // Also create unanchored version, which starts with a .*? loop.
-  if (c.prog_->anchor_start()) {
-    c.prog_->set_start_unanchored(c.prog_->start());
-  } else {
-    Frag unanchored = c.Cat(c.DotStar(), all);
-    c.prog_->set_start_unanchored(unanchored.begin);
-  }
-
-  c.prog_->set_reversed(reversed);
-
-  // Hand ownership of prog_ to caller.
-  return c.Finish();
-}
-
-Prog* Compiler::Finish() {
-  if (failed_)
-    return NULL;
-
-  if (prog_->start() == 0 && prog_->start_unanchored() == 0) {
-    // No possible matches; keep Fail instruction only.
-    inst_len_ = 1;
-  }
-
-  // Trim instruction to minimum array and transfer to Prog.
-  Trim();
-  prog_->inst_ = inst_;
-  prog_->size_ = inst_len_;
-  inst_ = NULL;
-
-  // Compute byte map.
-  prog_->ComputeByteMap();
-
-  prog_->Optimize();
-
-  // Record remaining memory for DFA.
-  if (max_mem_ <= 0) {
-    prog_->set_dfa_mem(1<<20);
-  } else {
-    int64 m = max_mem_ - sizeof(Prog) - inst_len_*sizeof(Prog::Inst);
-    if (m < 0)
-      m = 0;
-    prog_->set_dfa_mem(m);
-  }
-
-  Prog* p = prog_;
-  prog_ = NULL;
-  return p;
-}
-
-// Converts Regexp to Prog.
-Prog* Regexp::CompileToProg(int64 max_mem) {
-  return Compiler::Compile(this, false, max_mem);
-}
-
-Prog* Regexp::CompileToReverseProg(int64 max_mem) {
-  return Compiler::Compile(this, true, max_mem);
-}
-
-Frag Compiler::DotStar() {
-  return Star(ByteRange(0x00, 0xff, false), true);
-}
-
-// Compiles RE set to Prog.
-Prog* Compiler::CompileSet(const RE2::Options& options, RE2::Anchor anchor,
-                           Regexp* re) {
-  Compiler c;
-
-  Regexp::ParseFlags pf = static_cast<Regexp::ParseFlags>(options.ParseFlags());
-  c.Setup(pf, options.max_mem(), anchor);
-
-  // Compile alternation of fragments.
-  Frag all = c.WalkExponential(re, Frag(), 2*c.max_inst_);
-  re->Decref();
-  if (c.failed_)
-    return NULL;
-
-  if (anchor == RE2::UNANCHORED) {
-    // The trailing .* was added while handling kRegexpHaveMatch.
-    // We just have to add the leading one.
-    all = c.Cat(c.DotStar(), all);
-  }
-
-  c.prog_->set_start(all.begin);
-  c.prog_->set_start_unanchored(all.begin);
-  c.prog_->set_anchor_start(true);
-  c.prog_->set_anchor_end(true);
-
-  Prog* prog = c.Finish();
-  if (prog == NULL)
-    return NULL;
-
-  // Make sure DFA has enough memory to operate,
-  // since we're not going to fall back to the NFA.
-  bool failed;
-  StringPiece sp = "hello, world";
-  prog->SearchDFA(sp, sp, Prog::kAnchored, Prog::kManyMatch,
-                  NULL, &failed, NULL);
-  if (failed) {
-    delete prog;
-    return NULL;
-  }
-
-  return prog;
-}
-
-Prog* Prog::CompileSet(const RE2::Options& options, RE2::Anchor anchor,
-                       Regexp* re) {
-  return Compiler::CompileSet(options, anchor, re);
-}
-
-}  // namespace re2