Add support for FreeBSD's LD_32_LIBRARY_PATH

[dim]

Summary

Because the dynamic linker for 32-bit executables on 64-bit FreeBSD uses
the environment variable LD_32_LIBRARY_PATH instead of
LD_LIBRARY_PATH to find needed dynamic libraries, running the 32-bit
parts of the dynamic ASan tests will fail with errors similar to:

ld-elf32.so.1: Shared object "libclang_rt.asan-i386.so" not found, required by "Asan-i386-inline-Dynamic-Test"

This adds support for setting up LD_32_LIBRARY_PATH for the unit and
regression tests. It will likely also require a minor change to the
TestingConfig class in llvm/utils/lit/lit.

[arichardson]

LGTM. This reduces the check-asan-dynamic test failures from 209 to 50 if I also apply the -pthread patch.

compiler-rt/trunk/test/asan/Unit/lit.site.cfg.py.in

 @LIT_SITE_CFG_IN_HEADER@
 
 import os
+import platform
 
 # Load common config for all compiler-rt unit tests.
 lit_config.load_config(config, "@COMPILER_RT_BINARY_DIR@/unittests/lit.common.unit.configured")
 
 def push_ld_library_path(config, new_path):
   new_ld_library_path = os.path.pathsep.join(
     (new_path, config.environment.get('LD_LIBRARY_PATH', '')))
   config.environment['LD_LIBRARY_PATH'] = new_ld_library_path
 
+  if platform.system() == 'FreeBSD':
+    new_ld_32_library_path = os.path.pathsep.join(
+      (new_path, config.environment.get('LD_32_LIBRARY_PATH', '')))
+    config.environment['LD_32_LIBRARY_PATH'] = new_ld_32_library_path
+
 # Setup config name.
 config.name = 'AddressSanitizer-Unit'
 
 # Setup test source and exec root. For unit tests, we define
 # it as build directory with ASan unit tests.
 # FIXME: De-hardcode this path.
 if @ASAN_TEST_DYNAMIC@:
   test_dir = "dynamic"

compiler-rt/trunk/test/asan/lit.cfg.py

elif platform.system() == 'Darwin':
     dynamic_library_lookup_var = 'DYLD_LIBRARY_PATH'
   else:
     dynamic_library_lookup_var = 'LD_LIBRARY_PATH'
 
   new_ld_library_path = os.path.pathsep.join(
     (new_path, config.environment.get(dynamic_library_lookup_var, '')))
   config.environment[dynamic_library_lookup_var] = new_ld_library_path
 
+  if platform.system() == 'FreeBSD':
+    dynamic_library_lookup_var = 'LD_32_LIBRARY_PATH'
+    new_ld_32_library_path = os.path.pathsep.join(
+      (new_path, config.environment.get(dynamic_library_lookup_var, '')))
+    config.environment[dynamic_library_lookup_var] = new_ld_32_library_path
+
 # Setup config name.
 config.name = 'AddressSanitizer' + config.name_suffix
 
 # Platform-specific default ASAN_OPTIONS for lit tests.
 default_asan_opts = list(config.default_sanitizer_opts)
 
 # On Darwin, leak checking is not enabled by default. Enable for x86_64
 # tests to prevent regressions

 def build_invocation(compile_flags):
   return " " + " ".join([config.clang] + compile_flags) + " "
 
 config.substitutions.append( ("%clang ", build_invocation(target_cflags)) )
 config.substitutions.append( ("%clangxx ", build_invocation(target_cxxflags)) )
 config.substitutions.append( ("%clang_asan ", build_invocation(clang_asan_cflags)) )
 config.substitutions.append( ("%clangxx_asan ", build_invocation(clang_asan_cxxflags)) )
 if config.asan_dynamic:
-  if config.host_os in ['Linux', 'NetBSD', 'SunOS']:
+  if config.host_os in ['Linux', 'FreeBSD', 'NetBSD', 'SunOS']:
     shared_libasan_path = os.path.join(config.compiler_rt_libdir, "libclang_rt.asan{}.so".format(config.target_suffix))
   elif config.host_os == 'Darwin':
     shared_libasan_path = os.path.join(config.compiler_rt_libdir, 'libclang_rt.asan_{}_dynamic.dylib'.format(config.apple_platform))
   else:
     lit_config.warning('%shared_libasan substitution not set but dynamic ASan is available.')
     shared_libasan_path = None
 
   if shared_libasan_path is not None:

compiler-rt/trunk/test/xray/Unit/lit.site.cfg.py.in

 @LIT_SITE_CFG_IN_HEADER@
 
 import os
+import platform
 
 # Load common config for all compiler-rt unit tests.
 lit_config.load_config(config, "@COMPILER_RT_BINARY_DIR@/unittests/lit.common.unit.configured")
 
 # Setup config name.
 config.name = 'XRay-Unit'
 
 config.test_exec_root = "@COMPILER_RT_BINARY_DIR@/lib/xray/tests"
 config.test_source_root = config.test_exec_root
 
 # Do not patch the XRay unit tests pre-main, and also make the error logging
 # verbose to get a more accurate error logging mechanism.
 config.environment['XRAY_OPTIONS'] = 'patch_premain=false'
 
 # Add the LLVM Library directory to the LD_LIBRARY_PATH to allow tests to look
 # up the shared libraries.
 if 'LD_LIBRARY_PATH' in os.environ:
   libdirs = os.path.pathsep.join((config.llvm_lib_dir, os.environ['LD_LIBRARY_PATH']))
   config.environment['LD_LIBRARY_PATH'] = libdirs
 else:
   config.environment['LD_LIBRARY_PATH'] = config.llvm_lib_dir
+
+if platform.system() == 'FreeBSD':
+  if 'LD_32_LIBRARY_PATH' in os.environ:
+    libdirs = os.path.pathsep.join((config.llvm_lib_dir, os.environ['LD_32_LIBRARY_PATH']))
+    config.environment['LD_32_LIBRARY_PATH'] = libdirs
+  else:
+    config.environment['LD_32_LIBRARY_PATH'] = config.llvm_lib_dir