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//===-- Implementation of libc death test executors -----------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#include "src/__support/common.h"
#include "src/__support/macros/config.h"
#include <stddef.h>
#include <stdint.h>
#ifdef LIBC_TARGET_ARCH_IS_AARCH64
#include "src/sys/auxv/getauxval.h"
#endif
namespace LIBC_NAMESPACE_DECL {
int bcmp(const void *lhs, const void *rhs, size_t count);
void bzero(void *ptr, size_t count);
int memcmp(const void *lhs, const void *rhs, size_t count);
void *memcpy(void *__restrict, const void *__restrict, size_t);
void *memmove(void *dst, const void *src, size_t count);
void *memset(void *ptr, int value, size_t count);
int atexit(void (*func)(void));
// TODO: It seems that some old test frameworks does not use
// add_libc_hermetic_test properly. Such that they won't get correct linkage
// against the object containing this function. We create a dummy function that
// always returns 0 to indicate a failure.
[[gnu::weak]] unsigned long getauxval(unsigned long id) { return 0; }
} // namespace LIBC_NAMESPACE_DECL
namespace {
// Integration tests cannot use the SCUDO standalone allocator as SCUDO pulls
// various other parts of the libc. Since SCUDO development does not use
// LLVM libc build rules, it is very hard to keep track or pull all that SCUDO
// requires. Hence, as a work around for this problem, we use a simple allocator
// which just hands out continuous blocks from a statically allocated chunk of
// memory.
static constexpr uint64_t MEMORY_SIZE = 65336;
static uint8_t memory[MEMORY_SIZE];
static uint8_t *ptr = memory;
} // anonymous namespace
extern "C" {
// Hermetic tests rely on the following memory functions. This is because the
// compiler code generation can emit calls to them. We want to map the external
// entrypoint to the internal implementation of the function used for testing.
// This is done manually as not all targets support aliases.
int bcmp(const void *lhs, const void *rhs, size_t count) {
return LIBC_NAMESPACE::bcmp(lhs, rhs, count);
}
void bzero(void *ptr, size_t count) { LIBC_NAMESPACE::bzero(ptr, count); }
int memcmp(const void *lhs, const void *rhs, size_t count) {
return LIBC_NAMESPACE::memcmp(lhs, rhs, count);
}
void *memcpy(void *__restrict dst, const void *__restrict src, size_t count) {
return LIBC_NAMESPACE::memcpy(dst, src, count);
}
void *memmove(void *dst, const void *src, size_t count) {
return LIBC_NAMESPACE::memmove(dst, src, count);
}
void *memset(void *ptr, int value, size_t count) {
return LIBC_NAMESPACE::memset(ptr, value, count);
}
// This is needed if the test was compiled with '-fno-use-cxa-atexit'.
int atexit(void (*func)(void)) { return LIBC_NAMESPACE::atexit(func); }
constexpr uint64_t ALIGNMENT = alignof(uintptr_t);
void *malloc(size_t s) {
// Keep the bump pointer aligned on an eight byte boundary.
s = ((s + ALIGNMENT - 1) / ALIGNMENT) * ALIGNMENT;
void *mem = ptr;
ptr += s;
return static_cast<uint64_t>(ptr - memory) >= MEMORY_SIZE ? nullptr : mem;
}
void free(void *) {}
void *realloc(void *mem, size_t s) {
if (mem == nullptr)
return malloc(s);
uint8_t *newmem = reinterpret_cast<uint8_t *>(malloc(s));
if (newmem == nullptr)
return nullptr;
uint8_t *oldmem = reinterpret_cast<uint8_t *>(mem);
// We use a simple for loop to copy the data over.
// If |s| is less the previous alloc size, the copy works as expected.
// If |s| is greater than the previous alloc size, then garbage is copied
// over to the additional part in the new memory block.
for (size_t i = 0; i < s; ++i)
newmem[i] = oldmem[i];
return newmem;
}
// The unit test framework uses pure virtual functions. Since hermetic tests
// cannot depend C++ runtime libraries, implement dummy functions to support
// the virtual function runtime.
void __cxa_pure_virtual() {
// A pure virtual being called is an error so we just trap.
__builtin_trap();
}
// Hermetic tests are linked with -nostdlib. BFD linker expects
// __dso_handle when -nostdlib is used.
void *__dso_handle = nullptr;
#ifdef LIBC_TARGET_ARCH_IS_AARCH64
// Due to historical reasons, libgcc on aarch64 may expect __getauxval to be
// defined. See also https://gcc.gnu.org/pipermail/gcc-cvs/2020-June/300635.html
unsigned long __getauxval(unsigned long id) {
return LIBC_NAMESPACE::getauxval(id);
}
#endif
} // extern "C"
void *operator new(size_t size, void *ptr) { return ptr; }
void *operator new(size_t size) { return malloc(size); }
void *operator new[](size_t size) { return malloc(size); }
void operator delete(void *) {
// The libc runtime should not use the global delete operator. Hence,
// we just trap here to catch any such accidental usages.
__builtin_trap();
}
void operator delete(void *ptr, size_t size) { __builtin_trap(); }
// Defining members in the std namespace is not preferred. But, we do it here
// so that we can use it to define the operator new which takes std::align_val_t
// argument.
namespace std {
enum class align_val_t : size_t {};
} // namespace std
void operator delete(void *mem, std::align_val_t) noexcept { __builtin_trap(); }
void operator delete(void *mem, unsigned int, std::align_val_t) noexcept {
__builtin_trap();
}
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