[llvm-config] Report --bindir based on LLVM_TOOLS_INSTALL_DIR

[loladiro]

Summary

LLVM_TOOLS_INSTALL_DIR was introduced in r272200 in order to override the directory
name into which to install LLVM's executable. However, llvm-config --bindir still reported
$PREFIX/bin independent of what LLVM_TOOLS_INSTALL_DIR was set to.

This fixes the out-of-tree clang standalone build for me.

[tstellar]

tools/llvm-config/llvm-config.cpp

331

LLVM_TOOLS_INSTALL_DIR can be a path relative to CMAKE_INSTALL_PREFIX or it can be an absolute path. So this won't work if it's an absolute path.

[beanz]

I'm confused. In what situation is llvm-config installed into a directory that isn't the LLVM_TOOLS_INSTALL_DIR? It seems to me that if llvm-config is installed in LLVM_TOOLS_INSTALL_DIR this should work.

[loladiro]

Not sure what you're asking. llvm-config is certainly generally installed there, but --bindir is wrong without this patch, so people using that will be confused (at least that was the case when I wrote this patch - it's been a while).

[tstellar]

In D22499#769091, @beanz wrote:

I'm confused. In what situation is llvm-config installed into a directory that isn't the LLVM_TOOLS_INSTALL_DIR? It seems to me that if llvm-config is installed in LLVM_TOOLS_INSTALL_DIR this should work.

If LLVM_TOOLS_INSTALL_DIIR = /usr/libexec/llvm, then --bindir will be wrong, also if LLVM_TOOLS_INSTALL_DIR is not CMAKE_INSTALL_PREFIX/bin, then --includedir and --libdir will be wrong.

[beanz]

Ah! I see now. Probably the only thing that needs to be changed is handling LLVM_TOOLS_INSTALL_DIR being absolute. Otherwise the patch seems good to me.

[loladiro]

Handle absolute path case

I think this should work. Take a look.

[beanz]

That looks like that should work to me. Seems good. @tstellar, does this resolve your issue?

[tstellar]

Yes, this is fine with me. Thanks.

tools/llvm-config/BuildVariables.inc.in

 #define LLVM_DYLIB_COMPONENTS "@LLVM_DYLIB_COMPONENTS@"
 #define LLVM_DYLIB_VERSION "@LLVM_DYLIB_VERSION@"
 #define LLVM_HAS_GLOBAL_ISEL "@LLVM_HAS_GLOBAL_ISEL@"
+#define LLVM_TOOLS_INSTALL_DIR "@LLVM_TOOLS_INSTALL_DIR@"

tools/llvm-config/llvm-config.cpp

   } else {
     ActivePrefix = CurrentExecPrefix;
     ActiveIncludeDir = ActivePrefix + "/include";
-    ActiveBinDir = ActivePrefix + "/bin";
+    ActiveBinDir = ActivePrefix + "/" + LLVM_TOOLS_INSTALL_DIR;
     ActiveLibDir = ActivePrefix + "/lib" + LLVM_LIBDIR_SUFFIX;
     ActiveIncludeOption = "-I" + ActiveIncludeDir;
   }