llvm/llvm/lib/Support/SmallVector.cpp

//===- llvm/ADT/SmallVector.cpp - 'Normally small' vectors ----------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements the SmallVector class.
//
//===----------------------------------------------------------------------===//

#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Support/MemAlloc.h"
#include <cstdint>
#ifdef LLVM_ENABLE_EXCEPTIONS
#include <stdexcept>
#endif
usingnamespacellvm;

// Check that no bytes are wasted and everything is well-aligned.
namespace {
// These structures may cause binary compat warnings on AIX. Suppress the
// warning since we are only using these types for the static assertions below.
#if defined(_AIX)
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Waix-compat"
#endif
struct Struct16B { … };
struct Struct32B { … };
#if defined(_AIX)
#pragma GCC diagnostic pop
#endif
}
static_assert …;
static_assert …;
static_assert …;
static_assert …;
static_assert …;
static_assert …;

static_assert …;

/// Report that MinSize doesn't fit into this vector's size type. Throws
/// std::length_error or calls report_fatal_error.
[[noreturn]] static void report_size_overflow(size_t MinSize, size_t MaxSize);
static void report_size_overflow(size_t MinSize, size_t MaxSize) { … }

/// Report that this vector is already at maximum capacity. Throws
/// std::length_error or calls report_fatal_error.
[[noreturn]] static void report_at_maximum_capacity(size_t MaxSize);
static void report_at_maximum_capacity(size_t MaxSize) { … }

// Note: Moving this function into the header may cause performance regression.
template <class Size_T>
static size_t getNewCapacity(size_t MinSize, size_t TSize, size_t OldCapacity) { … }

/// If vector was first created with capacity 0, getFirstEl() points to the
/// memory right after, an area unallocated. If a subsequent allocation,
/// that grows the vector, happens to return the same pointer as getFirstEl(),
/// get a new allocation, otherwise isSmall() will falsely return that no
/// allocation was done (true) and the memory will not be freed in the
/// destructor. If a VSize is given (vector size), also copy that many
/// elements to the new allocation - used if realloca fails to increase
/// space, and happens to allocate precisely at BeginX.
/// This is unlikely to be called often, but resolves a memory leak when the
/// situation does occur.
static void *replaceAllocation(void *NewElts, size_t TSize, size_t NewCapacity,
                               size_t VSize = 0) { … }

// Note: Moving this function into the header may cause performance regression.
template <class Size_T>
void *SmallVectorBase<Size_T>::mallocForGrow(void *FirstEl, size_t MinSize,
                                             size_t TSize,
                                             size_t &NewCapacity) { … }

// Note: Moving this function into the header may cause performance regression.
template <class Size_T>
void SmallVectorBase<Size_T>::grow_pod(void *FirstEl, size_t MinSize,
                                       size_t TSize) { … }

template class llvm::SmallVectorBase<uint32_t>;

// Disable the uint64_t instantiation for 32-bit builds.
// Both uint32_t and uint64_t instantiations are needed for 64-bit builds.
// This instantiation will never be used in 32-bit builds, and will cause
// warnings when sizeof(Size_T) > sizeof(size_t).
#if SIZE_MAX > UINT32_MAX
template class llvm::SmallVectorBase<uint64_t>;

// Assertions to ensure this #if stays in sync with SmallVectorSizeType.
static_assert …;
#else
static_assert(sizeof(SmallVectorSizeType<char>) == sizeof(uint32_t),
              "Expected SmallVectorBase<uint32_t> variant to be in use.");
#endif