[lit] Don't set DYLD_LIBRARY_PATH when DYLD_INSERT_LIBRARIES is set.

Setting DYLD_INSERT_LIBRARIES to the Asan runtime and DYLD_LIBRARY_PATH
to the LLVM shared library dir causes the test suite to crash with a
segfault. We see this on the LLDB sanitized bot [1] on GreenDragon. I've
spent some time investigating, but I'm not sure what's going on (yet).

Originally I thought this was because we were building compiler-rt and
were loading an incompatible, just-built Asan library. However, the
issue persists even without compiler-rt. It doesn't look like the Asan
runtime is opening any other libraries that might be found in LLVM's
shared library dir and talking to the team confirms that. Another
possible explanation is that we're loading lldb form a place we don't
expect, but that doesn't make sense either, because DYLD_LIBRARY_PATH is
always set without the crash. I tried different Python versions and
interpreters but the issue persist.

As a (temporary?) workaround I propose not setting DYLD_LIBRARY_PATH
when DYLD_INSERT_LIBRARIES is set so we can turn the Asan bot on again
and get useful results.

[1] http://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake-sanitized/

Differential revision: https://reviews.llvm.org/D66845

llvm-svn: 370135

1 files changed, 15 insertions, 13 deletions

diff --git a/lldb/lit/Suite/lit.cfg b/lldb/lit/Suite/lit.cfg
index 24dc8682f39..a0d4dc4ff31 100644
--- a/lldb/lit/Suite/lit.cfg
+++ b/lldb/lit/Suite/lit.cfg
@@ -31,7 +31,6 @@ if 'Address' in config.llvm_use_sanitizer:
                            'libclang_rt.asan_osx_dynamic.dylib')
     config.environment['DYLD_INSERT_LIBRARIES'] = runtime
 
-# Shared library build of LLVM may require LD_LIBRARY_PATH or equivalent.
 def find_shlibpath_var():
   if platform.system() in ['Linux', 'FreeBSD', 'NetBSD', 'SunOS']:
     yield 'LD_LIBRARY_PATH'
@@ -40,18 +39,21 @@ def find_shlibpath_var():
   elif platform.system() == 'Windows':
     yield 'PATH'
 
-for shlibpath_var in find_shlibpath_var():
-  # In stand-alone build llvm_shlib_dir specifies LLDB's lib directory
-  # while llvm_libs_dir specifies LLVM's lib directory.
-  shlibpath = os.path.pathsep.join(
-    (config.llvm_shlib_dir,
-     config.llvm_libs_dir,
-     config.environment.get(shlibpath_var, '')))
-  config.environment[shlibpath_var] = shlibpath
-  break
-else:
-  lit_config.warning("unable to inject shared library path on '{}'"
-                     .format(platform.system()))
+if not config.environment['DYLD_INSERT_LIBRARIES']:
+  # Shared library build of LLVM may require LD_LIBRARY_PATH or equivalent.
+  # This clashes with DYLD_INSERT_LIBRARIES which is needed on Darwin.
+  for shlibpath_var in find_shlibpath_var():
+    # In stand-alone build llvm_shlib_dir specifies LLDB's lib directory while
+    # llvm_libs_dir specifies LLVM's lib directory.
+    shlibpath = os.path.pathsep.join(
+      (config.llvm_shlib_dir,
+      config.llvm_libs_dir,
+      config.environment.get(shlibpath_var, '')))
+    config.environment[shlibpath_var] = shlibpath
+    break
+  else:
+    lit_config.warning("unable to inject shared library path on '{}'"
+                      .format(platform.system()))
 
 # Build dotest command.
 dotest_cmd = [config.dotest_path, '-q']