From 374571301dc8e9bc9fdd1d70f86015de198673bd Mon Sep 17 00:00:00 2001 From: Tom Stellard Date: Mon, 10 Jun 2019 22:12:56 +0000 Subject: CMake: Make most target symbols hidden by default Summary: For builds with LLVM_BUILD_LLVM_DYLIB=ON and BUILD_SHARED_LIBS=OFF this change makes all symbols in the target specific libraries hidden by default. A new macro called LLVM_EXTERNAL_VISIBILITY has been added to mark symbols in these libraries public, which is mainly needed for the definitions of the LLVMInitialize* functions. This patch reduces the number of public symbols in libLLVM.so by about 25%. This should improve load times for the dynamic library and also make abi checker tools, like abidiff require less memory when analyzing libLLVM.so One side-effect of this change is that for builds with LLVM_BUILD_LLVM_DYLIB=ON and LLVM_LINK_LLVM_DYLIB=ON some unittests that access symbols that are no longer public will need to be statically linked. Before and after public symbol counts (using gcc 8.2.1, ld.bfd 2.31.1): nm before/libLLVM-9svn.so | grep ' [A-Zuvw] ' | wc -l 36221 nm after/libLLVM-9svn.so | grep ' [A-Zuvw] ' | wc -l 26278 Reviewers: chandlerc, beanz, mgorny, rnk, hans Reviewed By: rnk, hans Subscribers: Jim, hiraditya, michaelplatings, chapuni, jholewinski, arsenm, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, javed.absar, sbc100, jgravelle-google, aheejin, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, zzheng, edward-jones, mgrang, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, kristina, jsji, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D54439 llvm-svn: 362990 --- llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCTargetDesc.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCTargetDesc.cpp') diff --git a/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCTargetDesc.cpp b/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCTargetDesc.cpp index 21545c39164..82e8e91afdd 100644 --- a/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCTargetDesc.cpp +++ b/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyMCTargetDesc.cpp @@ -95,7 +95,7 @@ static MCTargetStreamer *createNullTargetStreamer(MCStreamer &S) { } // Force static initialization. -extern "C" void LLVMInitializeWebAssemblyTargetMC() { +extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeWebAssemblyTargetMC() { for (Target *T : {&getTheWebAssemblyTarget32(), &getTheWebAssemblyTarget64()}) { // Register the MC asm info. -- cgit v1.2.3