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//===--- ContinuousRangeMap.h - Map with int range as key -------*- C++ -*-===//
// The LLVM Compiler Infrastructure
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
// This file defines the ContinuousRangeMap class, which is a highly
// specialized container used by serialization.
#include "clang/Basic/LLVM.h"
#include "llvm/ADT/SmallVector.h"
#include <algorithm>
#include <utility>
namespace clang {
/// \brief A map from continuous integer ranges to some value, with a very
/// specialized interface.
/// CRM maps from integer ranges to values. The ranges are continuous, i.e.
/// where one ends, the next one begins. So if the map contains the stops I0-3,
/// the first range is from I0 to I1, the second from I1 to I2, the third from
/// I2 to I3 and the last from I3 to infinity.
/// Ranges must be inserted in order. Inserting a new stop I4 into the map will
/// shrink the fourth range to I3 to I4 and add the new range I4 to inf.
template <typename Int, typename V, unsigned InitialCapacity>
class ContinuousRangeMap {
typedef std::pair<Int, V> value_type;
typedef value_type &reference;
typedef const value_type &const_reference;
typedef value_type *pointer;
typedef const value_type *const_pointer;
typedef SmallVector<value_type, InitialCapacity> Representation;
Representation Rep;
struct Compare {
bool operator ()(const_reference L, Int R) const {
return L.first < R;
bool operator ()(Int L, const_reference R) const {
return L < R.first;
bool operator ()(Int L, Int R) const {
return L < R;
bool operator ()(const_reference L, const_reference R) const {
return L.first < R.first;
void insert(const value_type &Val) {
if (!Rep.empty() && Rep.back() == Val)
assert((Rep.empty() || Rep.back().first < Val.first) &&
"Must insert keys in order.");
void insertOrReplace(const value_type &Val) {
iterator I = std::lower_bound(Rep.begin(), Rep.end(), Val, Compare());
if (I != Rep.end() && I->first == Val.first) {
I->second = Val.second;
Rep.insert(I, Val);
typedef typename Representation::iterator iterator;
typedef typename Representation::const_iterator const_iterator;
iterator begin() { return Rep.begin(); }
iterator end() { return Rep.end(); }
const_iterator begin() const { return Rep.begin(); }
const_iterator end() const { return Rep.end(); }
iterator find(Int K) {
iterator I = std::upper_bound(Rep.begin(), Rep.end(), K, Compare());
// I points to the first entry with a key > K, which is the range that
// follows the one containing K.
if (I == Rep.begin())
return Rep.end();
return I;
const_iterator find(Int K) const {
return const_cast<ContinuousRangeMap*>(this)->find(K);
reference back() { return Rep.back(); }
const_reference back() const { return Rep.back(); }
/// \brief An object that helps properly build a continuous range map
/// from a set of values.
class Builder {
ContinuousRangeMap &Self;
Builder(const Builder&) = delete;
Builder &operator=(const Builder&) = delete;
explicit Builder(ContinuousRangeMap &Self) : Self(Self) { }
~Builder() {
std::sort(Self.Rep.begin(), Self.Rep.end(), Compare());
std::unique(Self.Rep.begin(), Self.Rep.end(),
[](const_reference A, const_reference B) {
// FIXME: we should not allow any duplicate keys, but there are a lot of
// duplicate 0 -> 0 mappings to remove first.
assert((A == B || A.first != B.first) &&
"ContinuousRangeMap::Builder given non-unique keys");
return A == B;
void insert(const value_type &Val) {
friend class Builder;