tree 5721fa8400838bab2b233d009bf6ef00a93782d2
parent 49269d597a13548b3fea01dd3fc328a71aec206f
author Rui Ueyama <ruiu@google.com> 1560169001 +0000
committer Rui Ueyama <ruiu@google.com> 1560169001 +0000

[LLD][COFF] Fix missing MergeChunk::Instances cleanup in COFF::link()

Patch by Erik McClure with a modification to rebase to HEAD.

When calling `COFF::link()` with `CanExitEarly` set to `false`, the
function needs to clean up several global variable caches to ensure that
the next invocation of the function starts from a clean slate. The
`MergeChunk::Instances` cache is missing from this cleanup code, and as
a result will create nondeterministic memory access errors and sometimes
infinite loops due to invalid memory being referenced on the next call
to `COFF::link()`.

This fix simply clears `MergeChunk::Instances` before exiting the function.

An additional review of the COFF library was made to try and find any
other missing global caches, but I was unable to find any other than
`MergeChunk`. Someone more familiar with the global variables might want
to do their own check.

This fix was made to support inNative
<https://github.com/innative-sdk/innative>'s `.wast` script compiler,
which must build multiple incremental builds. It relies on statically
linking LLD because the entire compiler must be a single statically
embeddable library, thus preventing it from being able to call LLD as a
new process.

Differential Revision: https://reviews.llvm.org/D63042

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@362930 91177308-0d34-0410-b5e6-96231b3b80d8