//===- MemAlloc.h - Memory allocation functions -----------------*- C++ -*-===//

//

// 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

//

//===----------------------------------------------------------------------===//

/// \file

///

/// This file defines counterparts of C library allocation functions defined in

/// the namespace 'std'. The new allocation functions crash on allocation

/// failure instead of returning null pointer.

///

//===----------------------------------------------------------------------===//

#ifndef LLVM_SUPPORT_MEMALLOC_H

#define LLVM_SUPPORT_MEMALLOC_H

#include "llvm/Support/Compiler.h"

#include "llvm/Support/ErrorHandling.h"

#include <cstdlib>

namespace llvm {

LLVM_ATTRIBUTE_RETURNS_NONNULL inline void *safe_malloc(size_t Sz) {

  void *Result = std::malloc(Sz);

  if (Result == nullptr) {

    // It is implementation-defined whether allocation occurs if the space

    // requested is zero (ISO/IEC 9899:2018 7.22.3). Retry, requesting

    // non-zero, if the space requested was zero.

    if (Sz == 0)

      return safe_malloc(1);

    report_bad_alloc_error("Allocation failed");

  }

  return Result;

}

LLVM_ATTRIBUTE_RETURNS_NONNULL inline void *safe_calloc(size_t Count,

                                                        size_t Sz) {

  void *Result = std::calloc(Count, Sz);

  if (Result == nullptr) {

    // It is implementation-defined whether allocation occurs if the space

    // requested is zero (ISO/IEC 9899:2018 7.22.3). Retry, requesting

    // non-zero, if the space requested was zero.

    if (Count == 0 || Sz == 0)

      return safe_malloc(1);

    report_bad_alloc_error("Allocation failed");

  }

  return Result;

}

LLVM_ATTRIBUTE_RETURNS_NONNULL inline void *safe_realloc(void *Ptr, size_t Sz) {

  void *Result = std::realloc(Ptr, Sz);

  if (Result == nullptr) {

    // It is implementation-defined whether allocation occurs if the space

    // requested is zero (ISO/IEC 9899:2018 7.22.3). Retry, requesting

    // non-zero, if the space requested was zero.

    if (Sz == 0)

      return safe_malloc(1);

    report_bad_alloc_error("Allocation failed");

  }

  return Result;

}

/// Allocate a buffer of memory with the given size and alignment.

///

/// When the compiler supports aligned operator new, this will use it to to

/// handle even over-aligned allocations.

///

/// However, this doesn't make any attempt to leverage the fancier techniques

/// like posix_memalign due to portability. It is mostly intended to allow

/// compatibility with platforms that, after aligned allocation was added, use

/// reduced default alignment.

LLVM_ATTRIBUTE_RETURNS_NONNULL LLVM_ATTRIBUTE_RETURNS_NOALIAS void *

allocate_buffer(size_t Size, size_t Alignment);

/// Deallocate a buffer of memory with the given size and alignment.

///

/// If supported, this will used the sized delete operator. Also if supported,

/// this will pass the alignment to the delete operator.

///

/// The pointer must have been allocated with the corresponding new operator,

/// most likely using the above helper.

void deallocate_buffer(void *Ptr, size_t Size, size_t Alignment);

} // namespace llvm

#endif