[LLVMdev] --enable-optimized breaks pass registration for dynamically loadable passes?

[Ben Ransford]

Hello all,

Is it well known that building LLVM with --enable-optimized causes
RegisterPass calls to be removed from dynamically loadable libraries
(i.e., those built with LOADABLE_MODULE=1)?

For example, here's what happens to the Hello pass (ToT on Darwin,
both with and without --enable-optimized):

$ pwd
/Users/ransford/llvm/lib/Transforms/Hello
$ nm -j Release+Asserts/Hello.o | c++filt -p | grep llvm::RegisterPass
$ nm -j Debug+Asserts/Hello.o | c++filt -p | grep llvm::RegisterPass
llvm::RegisterPass<(anonymous namespace)::Hello>::RegisterPass
llvm::RegisterPass<(anonymous namespace)::Hello>::RegisterPass
llvm::RegisterPass<(anonymous namespace)::Hello>::~RegisterPass
llvm::RegisterPass<(anonymous namespace)::Hello>::~RegisterPass
llvm::RegisterPass<(anonymous namespace)::Hello2>::RegisterPass
llvm::RegisterPass<(anonymous namespace)::Hello2>::RegisterPass
llvm::RegisterPass<(anonymous namespace)::Hello2>::~RegisterPass
llvm::RegisterPass<(anonymous namespace)::Hello2>::~RegisterPass

As you might expect, after 'make install' installs the libLLVMHello
library, 'opt -load libLLVMHello.dylib -help' shows hello and hello2
in the pass list for the Debug version but not for the Release
version.  Maybe I'm misunderstanding how dynamically loadable pass
modules are supposed to work, but I can't imagine that this behavior
was intentional.

I realize the Hello pass isn't top priority, but I'm developing my own
passes that live in dynamically loadable modules, and I'd like to help
clarify this in the docs if someone explains it to me.

-ben