[PATCH] D129129: CommandLine: Cleanup options and remove use of ManagedStatic

[Nicolai Hähnle via Phabricator via llvm-commits]

nhaehnle created this revision.
nhaehnle added reviewers: efriedma, lattner.
Herald added subscribers: mattd, gchakrabarti, asavonic, hiraditya.
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Herald added a project: LLVM.

Replace uses of ManagedStatics by function-local static variables.

Also fix a corruption issue when LLVM is used as a shared library in a
plugin setting.

Consider the case where A depends on B depends on LLVM, where B is a
shared compiler library built on LLVM that defines command-line options
because it can also be used in a non-plugin setting.

If A is loaded and unloaded multiple times, causing B to be loaded and
unloaded multiple times while LLVM *isn't* unloaded, then corruption
results without this change: as B is unloaded, its cl::opt globals
disappear but the GlobalParser still holds a (dangling) reference to
them. Furthermore, if A and B are loaded a second time, the cl::opt
globals are constructed again which fails because options of the
same name are still registered.

The straightforward fix is to remove options from the GlobalParser
in the cl::Option destructor (which was previously defaulted but
already non-trivial).


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D129129

Files:
  llvm/include/llvm/Support/CommandLine.h
  llvm/lib/Support/CommandLine.cpp
  llvm/lib/Target/ARM/ARMExpandPseudoInsts.cpp
  llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp

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