[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 ↗

(On Diff #64444)

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.

llvm/trunk/tools/llvm-config/BuildVariables.inc.in

 #define LLVM_BUILD_SYSTEM "@LLVM_BUILD_SYSTEM@"
 #define LLVM_HAS_RTTI @LLVM_HAS_RTTI@
 #define LLVM_ENABLE_DYLIB @LLVM_BUILD_LLVM_DYLIB@
 #define LLVM_LINK_DYLIB @LLVM_LINK_LLVM_DYLIB@
 #define LLVM_ENABLE_SHARED @BUILD_SHARED_LIBS@
 #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@"

llvm/trunk/tools/llvm-config/llvm-config.cpp

if (IsInDevelopmentTree) {
     }
 
     // We need to include files from both the source and object trees.
     ActiveIncludeOption =
         ("-I" + ActiveIncludeDir + " " + "-I" + ActiveObjRoot + "/include");
   } else {
     ActivePrefix = CurrentExecPrefix;
     ActiveIncludeDir = ActivePrefix + "/include";
-    ActiveBinDir = ActivePrefix + "/bin";
+    SmallString<PATH_MAX> path(StringRef(LLVM_TOOLS_INSTALL_DIR));
+    sys::fs::make_absolute(ActivePrefix, path);
+    ActiveBinDir = path.str();
     ActiveLibDir = ActivePrefix + "/lib" + LLVM_LIBDIR_SUFFIX;
     ActiveCMakeDir = ActiveLibDir + "/cmake/llvm";
     ActiveIncludeOption = "-I" + ActiveIncludeDir;
   }
 
   /// We only use `shared library` mode in cases where the static library form
   /// of the components provided are not available; note however that this is
   /// skipped if we're run from within the build dir. However, once installed,