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Diffstat (limited to 'lib/gwp_asan/stack_trace_compressor.h')
-rw-r--r-- | lib/gwp_asan/stack_trace_compressor.h | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/lib/gwp_asan/stack_trace_compressor.h b/lib/gwp_asan/stack_trace_compressor.h new file mode 100644 index 000000000000..dcbd9a3c1f0a --- /dev/null +++ b/lib/gwp_asan/stack_trace_compressor.h @@ -0,0 +1,38 @@ +//===-- stack_trace_compressor.h --------------------------------*- 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 +// +//===----------------------------------------------------------------------===// + +#ifndef GWP_ASAN_STACK_TRACE_COMPRESSOR_ +#define GWP_ASAN_STACK_TRACE_COMPRESSOR_ + +#include <stddef.h> +#include <stdint.h> + +// These functions implement stack frame compression and decompression. We store +// the zig-zag encoded pointer difference between frame[i] and frame[i - 1] as +// a variable-length integer. This can reduce the memory overhead of stack +// traces by 50%. + +namespace gwp_asan { +namespace compression { + +// For the stack trace in `Unpacked` with length `UnpackedSize`, pack it into +// the buffer `Packed` maximum length `PackedMaxSize`. The return value is the +// number of bytes that were written to the output buffer. +size_t pack(const uintptr_t *Unpacked, size_t UnpackedSize, uint8_t *Packed, + size_t PackedMaxSize); + +// From the packed stack trace in `Packed` of length `PackedSize`, write the +// unpacked stack trace of maximum length `UnpackedMaxSize` into `Unpacked`. +// Returns the number of full entries unpacked, or zero on error. +size_t unpack(const uint8_t *Packed, size_t PackedSize, uintptr_t *Unpacked, + size_t UnpackedMaxSize); + +} // namespace compression +} // namespace gwp_asan + +#endif // GWP_ASAN_STACK_TRACE_COMPRESSOR_ |