tree 3b6e1a10291687cf2cb2cad360eb50372749e95d
parent 9f1db094a06b640f9da1285064ae8ee994a1f1ec
author Mitch Phillips <mitchphillips@outlook.com> 1565903349 +0000
committer Mitch Phillips <mitchphillips@outlook.com> 1565903349 +0000

[GWP-ASan] Implement stack frame compression.

Summary:
This patch introduces stack frame compression to GWP-ASan. Each stack frame is
variable-length integer encoded as the difference between frame[i] and
frame[i - 1]. Furthermore, we use zig-zag encoding on the difference to ensure
that negative differences are also encoded into a relatively small number of
bytes.

Examples of what the compression looks like can be seen in
`gwp_asan/tests/compression.cpp`.

This compression can reduce the memory consumption cost of stack traces by
~50%.

Reviewers: vlad.tsyrklevich

Reviewed By: vlad.tsyrklevich

Subscribers: mgorny, #sanitizers, llvm-commits, eugenis, morehouse

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D66189

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@369048 91177308-0d34-0410-b5e6-96231b3b80d8