llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_common.cc

101 lines
3.1 KiB
C++

//===-- sanitizer_common.cc -----------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is shared between AddressSanitizer and ThreadSanitizer
// run-time libraries.
//===----------------------------------------------------------------------===//
#include "sanitizer_common.h"
#include "sanitizer_libc.h"
namespace __sanitizer {
void RawWrite(const char *buffer) {
static const char *kRawWriteError = "RawWrite can't output requested buffer!";
uptr length = (uptr)internal_strlen(buffer);
if (length != internal_write(2, buffer, length)) {
internal_write(2, kRawWriteError, internal_strlen(kRawWriteError));
Die();
}
}
uptr ReadFileToBuffer(const char *file_name, char **buff,
uptr *buff_size, uptr max_len) {
const uptr kMinFileLen = kPageSize;
uptr read_len = 0;
*buff = 0;
*buff_size = 0;
// The files we usually open are not seekable, so try different buffer sizes.
for (uptr size = kMinFileLen; size <= max_len; size *= 2) {
fd_t fd = internal_open(file_name, /*write*/ false);
if (fd == kInvalidFd) return 0;
UnmapOrDie(*buff, *buff_size);
*buff = (char*)MmapOrDie(size, __FUNCTION__);
*buff_size = size;
// Read up to one page at a time.
read_len = 0;
bool reached_eof = false;
while (read_len + kPageSize <= size) {
uptr just_read = internal_read(fd, *buff + read_len, kPageSize);
if (just_read == 0) {
reached_eof = true;
break;
}
read_len += just_read;
}
internal_close(fd);
if (reached_eof) // We've read the whole file.
break;
}
return read_len;
}
// We don't want to use std::sort to avoid including <algorithm>, as
// we may end up with two implementation of std::sort - one in instrumented
// code, and the other in runtime.
// qsort() from stdlib won't work as it calls malloc(), which results
// in deadlock in ASan allocator.
// We re-implement in-place sorting w/o recursion as straightforward heapsort.
void SortArray(uptr *array, uptr size) {
if (size < 2)
return;
// Stage 1: insert elements to the heap.
for (uptr i = 1; i < size; i++) {
uptr j, p;
for (j = i; j > 0; j = p) {
p = (j - 1) / 2;
if (array[j] > array[p])
Swap(array[j], array[p]);
else
break;
}
}
// Stage 2: swap largest element with the last one,
// and sink the new top.
for (uptr i = size - 1; i > 0; i--) {
Swap(array[0], array[i]);
uptr j, max_ind;
for (j = 0; j < i; j = max_ind) {
uptr left = 2 * j + 1;
uptr right = 2 * j + 2;
max_ind = j;
if (left < i && array[left] > array[max_ind])
max_ind = left;
if (right < i && array[right] > array[max_ind])
max_ind = right;
if (max_ind != j)
Swap(array[j], array[max_ind]);
else
break;
}
}
}
} // namespace __sanitizer