[PATCH] D137337: Replace LLVM_LIBDIR_SUFFIX by CMAKE_INSTALL_LIBDIR

[Saleem Abdulrasool via Phabricator via llvm-commits]

compnerd added inline comments.


================
Comment at: bolt/lib/RuntimeLibs/RuntimeLibrary.cpp:32
   SmallString<128> LibPath = llvm::sys::path::parent_path(Dir);
-  llvm::sys::path::append(LibPath, "lib" LLVM_LIBDIR_SUFFIX);
+  llvm::sys::path::append(LibPath, CMAKE_INSTALL_LIBDIR);
   if (!llvm::sys::fs::exists(LibPath)) {
----------------
Ericson2314 wrote:
> compnerd wrote:
> > serge-sans-paille wrote:
> > > Ericson2314 wrote:
> > > > mgorny wrote:
> > > > > Well, one thing I immediately notice is that technically `CMAKE_INSTALL_LIBDIR` can be an absolute path, while in many locations you are assuming it will always be relative. Not saying that's a blocker but I think you should add checks for that into `CMakeLists.txt`.
> > > > Yes I was working on this, and I intend to use `CMAKE_INSTALL_LIBDIR` with an absolute path.
> > > > 
> > > > OK if this isn't supported initially but we should ovoid regressing where possible.
> > > Turns out LLVM_LIBDIR_SUFFIX is used in several situations: (a) for the library install dir or (b) for the location where build artifact as stored in CMAKE_BINARY_DIR. (a) could accept a path but not (b), unless we derive it from (a) but I can see a lot of complication there for the testing step. Would that be ok to choke on CMAKE_INSTALL_LIBDIR being a path and not a directory component?
> > > 
> > I think that is absolutely reasonable.  There is the `CMAKE_INSTALL_FULL_LIBDIR` which should be the relatively absolute path (it is relative to `DESTDIR`).  The `CMAKE_INSTALL_LIBDIR` should be the relative component which is added to `CMAKE_INSTALL_PREFIX`.
> Please do not do this. In NixOS we uses absolute paths for these which are *not* within `CMAKE_INSTALL_PREFIX` and I would very much like that to continue to work, and have put a lot of effort into it.
> 
> (I am sorry I have been a bit AWAL on LLVM things in general but hopefully will have more time as we head into the new year.)
Why can NixOS not use `CMAKE_INSTALL_FULL_LIBDIR`?  That is computed to `${CMAKE_INSTALL_PREFIX}${CMAKE_INSTALL_LIBDIR}` only if it is not already defined to an absolute path.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D137337/new/

https://reviews.llvm.org/D137337