Install doesn't respect libdir / CMAKE_INSTALL_LIBDIR

[rossburton]

If I build llvm with a prefix of /foo and a libdir of bar, it still installs into /foo/lib.

[DavidSpickett]

Can you give an example cmake command? Not sure if this bug is to do with CMAKE_INSTALL_PREFIX or some other cmake prefix option.

[rossburton]

The CMake invocation is common across everything we build with CMake so somewhat verbose but the relevant bits are:

cmake
-DCMAKE_INSTALL_PREFIX:PATH=/foo
-DCMAKE_INSTALL_BINDIR:PATH=bin
-DCMAKE_INSTALL_SBINDIR:PATH=sbin
-DCMAKE_INSTALL_LIBEXECDIR:PATH=libexec
-DCMAKE_INSTALL_SYSCONFDIR:PATH=/etc
-DCMAKE_INSTALL_LOCALSTATEDIR:PATH=/var
-DCMAKE_INSTALL_LIBDIR:PATH=libbar
-DCMAKE_INSTALL_INCLUDEDIR:PATH=include
-DCMAKE_INSTALL_DATAROOTDIR:PATH=share
-DLIB_SUFFIX=bar

LLVM installs the libraries into /foo/lib, whereas other packages using the same arguments (such as json-c) install the libraries into /foo/libbar.

[DavidSpickett]

There are a lot of instances of:

      install(TARGETS ${name}
        COMPONENT ${name}
        ${export_to_flangtargets}
        LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
        ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX}
        RUNTIME DESTINATION "${CMAKE_INSTALL_BINDIR}")

Throughout llvm-project.

So if the dir name you wanted is lib<something> you could work around this problem by setting LLVM_LIBDIR_SUFFIX.

Patching llvm will get the llvm libs in the right place, though some cmake files are still placed in lib/.

$ git diff
diff --git a/llvm/cmake/modules/AddLLVM.cmake b/llvm/cmake/modules/AddLLVM.cmake
index 83772ed8d2b1..44d30bd8768a 100644
--- a/llvm/cmake/modules/AddLLVM.cmake
+++ b/llvm/cmake/modules/AddLLVM.cmake
@@ -974,8 +974,8 @@ macro(add_llvm_library name)
       endif()
       install(TARGETS ${name}
               ${export_to_llvmexports}
-              LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
-              ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX} COMPONENT ${name}
+              LIBRARY DESTINATION "${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}" COMPONENT ${name}
+              ARCHIVE DESTINATION "${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}" COMPONENT ${name}
               RUNTIME DESTINATION "${CMAKE_INSTALL_BINDIR}" COMPONENT ${name})
 
       if (NOT LLVM_ENABLE_IDE)

Will check how big of an impact it would be to change this.