mirror of
https://github.com/RPCS3/llvm.git
synced 2025-02-24 04:32:09 +00:00
67e53da671
Summary: returns_twice (most importantly, setjmp) functions are optimization-hostile: if local variable is promoted to register, and is changed between setjmp() and longjmp() calls, this update will be undone. This is the reason why "man setjmp" advises to mark all these locals as "volatile". This can not be enough for ASan, though: when it replaces static alloca with dynamic one, optionally called if UAR mode is enabled, it adds a whole lot of SSA values, and computations of local variable addresses, that can involve virtual registers, and cause unexpected behavior, when these registers are restored from buffer saved in setjmp. To fix this, just disable dynamic alloca and UAR tricks whenever we see a returns_twice call in the function. Reviewers: rnk Subscribers: llvm-commits, kcc Differential Revision: http://reviews.llvm.org/D11495 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@243561 91177308-0d34-0410-b5e6-96231b3b80d8