[clang-tools-extra] [test] Fix clang library dir in LD_LIBRARY_PATH For stand-alone build

[mgorny]

Summary

Prepend the clang library directory (determined using SHLIBDIR, alike
in clang) to the LD_LIBRARY_PATH to ensure that just-built clang
libraries will be used instead of a previous installed version.

When a stand-alone build is performed, LLVM_LIBS_DIR contains the path
to installed LLVM library directory. The same directory frequently
contains a previously installed version of clang. SHLIBDIR, on the other
hand, is always the build-tree directory, and therefore contains
the freshly built clang libraries.

In a non-stand-alone build, both paths will be the same and therefore
including them both will not cause any issues.

[mgorny]

Ping.

[mgorny]

Another ping. @beanz, any chance you could take a look at this?

[beanz]

Looks reasonable to me.

test/Unit/lit.cfg

 if platform.system() == 'Linux':
     shlibpath_var = 'LD_LIBRARY_PATH'
 elif platform.system() == 'Darwin':
     shlibpath_var = 'DYLD_LIBRARY_PATH'
 elif platform.system() == 'Windows':
     shlibpath_var = 'PATH'
 
 # Point the dynamic loader at dynamic libraries in 'lib'.
+shlibdir = getattr(config, 'shlibdir', None)
+if not shlibdir:
+    lit_config.fatal('No shlibdir set!')
 llvm_libs_dir = getattr(config, 'llvm_libs_dir', None)
 if not llvm_libs_dir:
     lit_config.fatal('No LLVM libs dir set!')
-shlibpath = os.path.pathsep.join((llvm_libs_dir,
+shlibpath = os.path.pathsep.join((shlibdir, llvm_libs_dir,
                                  config.environment.get(shlibpath_var,'')))
 
 # Win32 seeks DLLs along %PATH%.
-if sys.platform in ['win32', 'cygwin'] and os.path.isdir(config.shlibdir):
-    shlibpath = os.path.pathsep.join((config.shlibdir, shlibpath))
+if sys.platform in ['win32', 'cygwin'] and os.path.isdir(shlibdir):
+    shlibpath = os.path.pathsep.join((shlibdir, shlibpath))
 
 config.environment[shlibpath_var] = shlibpath

test/lit.cfg

if not clang_tools_dir:
         lit_config.fatal('No Clang tools dir set!')
     llvm_tools_dir = getattr(config, 'llvm_tools_dir', None)
     if not llvm_tools_dir:
         lit_config.fatal('No LLVM tools dir set!')
     path = os.path.pathsep.join((
             clang_tools_dir, llvm_tools_dir, config.environment['PATH']))
     config.environment['PATH'] = path
 
+    clang_libs_dir = getattr(config, 'clang_libs_dir', None)
+    if not clang_libs_dir:
+        lit_config.fatal('No Clang libs dir set!')
     llvm_libs_dir = getattr(config, 'llvm_libs_dir', None)
     if not llvm_libs_dir:
         lit_config.fatal('No LLVM libs dir set!')
-    path = os.path.pathsep.join((llvm_libs_dir,
+    path = os.path.pathsep.join((clang_libs_dir, llvm_libs_dir,
                                  config.environment.get('LD_LIBRARY_PATH','')))
     config.environment['LD_LIBRARY_PATH'] = path
 
 ###
 
 # Check that the object root is known.
 if config.test_exec_root is None:
     # Otherwise, we haven't loaded the site specific configuration (the user is

test/lit.site.cfg.in

 @LIT_SITE_CFG_IN_HEADER@
 
 import sys
 
 config.llvm_tools_dir = "@LLVM_TOOLS_DIR@"
 config.llvm_libs_dir = "@LLVM_LIBS_DIR@"
 config.lit_tools_dir = "@LLVM_LIT_TOOLS_DIR@"
 config.clang_tools_binary_dir = "@CLANG_TOOLS_BINARY_DIR@"
 config.clang_tools_dir = "@CLANG_TOOLS_DIR@"
+config.clang_libs_dir = "@SHLIBDIR@"
 config.python_executable = "@PYTHON_EXECUTABLE@"
 config.target_triple = "@TARGET_TRIPLE@"
 
 # Support substitution of the tools and libs dirs with user parameters. This is
 # used when we can't determine the tool dir at configuration time.
 try:
     config.clang_tools_dir = config.clang_tools_dir % lit_config.params
     config.llvm_tools_dir = config.llvm_tools_dir % lit_config.params
     config.llvm_libs_dir = config.llvm_libs_dir % lit_config.params
 except KeyError:
     e = sys.exc_info()[1]
     key, = e.args
     lit_config.fatal("unable to find %r parameter, use '--param=%s=VALUE'" % (key,key))
 
 # Let the main config do the real work.
 lit_config.load_config(config, "@CLANG_TOOLS_SOURCE_DIR@/test/lit.cfg")