llvm-6502/include/llvm/ADT/UniqueVector.h
David Majnemer c8a1169c93 IR: Add COMDATs to the IR
This new IR facility allows us to represent the object-file semantic of
a COMDAT group.

COMDATs allow us to tie together sections and make the inclusion of one
dependent on another. This is required to implement features like MS
ABI VFTables and optimizing away certain kinds of initialization in C++.

This functionality is only representable in COFF and ELF, Mach-O has no
similar mechanism.

Differential Revision: http://reviews.llvm.org/D4178

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211920 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-27 18:19:56 +00:00

107 lines
3.1 KiB
C++

//===-- llvm/ADT/UniqueVector.h ---------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ADT_UNIQUEVECTOR_H
#define LLVM_ADT_UNIQUEVECTOR_H
#include <cassert>
#include <map>
#include <vector>
namespace llvm {
//===----------------------------------------------------------------------===//
/// UniqueVector - This class produces a sequential ID number (base 1) for each
/// unique entry that is added. T is the type of entries in the vector. This
/// class should have an implementation of operator== and of operator<.
/// Entries can be fetched using operator[] with the entry ID.
template<class T> class UniqueVector {
public:
typedef typename std::vector<T> VectorType;
typedef typename VectorType::iterator iterator;
typedef typename VectorType::const_iterator const_iterator;
private:
// Map - Used to handle the correspondence of entry to ID.
std::map<T, unsigned> Map;
// Vector - ID ordered vector of entries. Entries can be indexed by ID - 1.
//
VectorType Vector;
public:
/// insert - Append entry to the vector if it doesn't already exist. Returns
/// the entry's index + 1 to be used as a unique ID.
unsigned insert(const T &Entry) {
// Check if the entry is already in the map.
unsigned &Val = Map[Entry];
// See if entry exists, if so return prior ID.
if (Val) return Val;
// Compute ID for entry.
Val = static_cast<unsigned>(Vector.size()) + 1;
// Insert in vector.
Vector.push_back(Entry);
return Val;
}
/// idFor - return the ID for an existing entry. Returns 0 if the entry is
/// not found.
unsigned idFor(const T &Entry) const {
// Search for entry in the map.
typename std::map<T, unsigned>::const_iterator MI = Map.find(Entry);
// See if entry exists, if so return ID.
if (MI != Map.end()) return MI->second;
// No luck.
return 0;
}
/// operator[] - Returns a reference to the entry with the specified ID.
///
const T &operator[](unsigned ID) const {
assert(ID-1 < size() && "ID is 0 or out of range!");
return Vector[ID - 1];
}
/// \brief Return an iterator to the start of the vector.
iterator begin() { return Vector.begin(); }
/// \brief Return an iterator to the start of the vector.
const_iterator begin() const { return Vector.begin(); }
/// \brief Return an iterator to the end of the vector.
iterator end() { return Vector.end(); }
/// \brief Return an iterator to the end of the vector.
const_iterator end() const { return Vector.end(); }
/// size - Returns the number of entries in the vector.
///
size_t size() const { return Vector.size(); }
/// empty - Returns true if the vector is empty.
///
bool empty() const { return Vector.empty(); }
/// reset - Clears all the entries.
///
void reset() {
Map.clear();
Vector.resize(0, 0);
}
};
} // End of namespace llvm
#endif // LLVM_ADT_UNIQUEVECTOR_H