FIXME: It should work on not only Linux but elf-targeting gnu ld.
For example if LLVM_DYLIB_COMPONENTS is "BitWriter Support", CMake emits the command line like;
-Wl,--whole-archive
lib/libLLVMBitWriter.a
lib/libLLVMSupport.a *1
-Wl,--no-whole-archive
lib/libLLVMCore.a
lib/libLLVMSupport.a *2
-lrt -ldl -ltinfo -lpthread -lm
It works since symbols in LLVMCore is resolved with not *2 but *1.
Unfortunately, --gc-sections is not powerful in this case to prune unused "visibility(default)" entries.
I am still experimenting other way not to rely on --whole-archive.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221591 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch adds a new CMake build setting LLVM_BUILD_LLVM_DYLIB, which defaults to OFF. When set to ON, this will generate a shared library containing most of LLVM. The contents of the shared library can be overriden by specifying LLVM_DYLIB_COMPONENTS. LLVM_DYLIB_COMPONENTS can be set to a semi-colon delimited list of any LLVM components that you llvm-config can resolve.
On Windows, unless you are using Cygwin, you must specify an explicit symbol export file using LLVM_EXPORTED_SYMBOL_FILE. On Cygwin and all unix-like platforms if you do not specify LLVM_EXPORTED_SYMBOL_FILE, an export file containing only the LLVM C API will be auto-generated from the list of LLVM components specified in LLVM_DYLIB_COMPONENTS.
Reviewers: rnk
Reviewed By: rnk
Subscribers: rnk, llvm-commits
Differential Revision: http://reviews.llvm.org/D5890
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220490 91177308-0d34-0410-b5e6-96231b3b80d8
