[clang] [clang-tools-extra] [llvm] [polly] [Unittest][Cygwin] Set $PATH when running unittests (PR #163947)

[Tomohiro Kashiwada via cfe-commits]

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@@ -19,12 +19,12 @@
 
 if platform.system() == "Darwin":
     shlibpath_var = "DYLD_LIBRARY_PATH"
-elif platform.system() == "Windows":
+elif platform.system() == "Windows" or sys.platform == "cygwin":
     shlibpath_var = "PATH"
 else:
     shlibpath_var = "LD_LIBRARY_PATH"
 config.environment[shlibpath_var] = os.path.pathsep.join(
-    ("@SHLIBDIR@", "@LLVM_LIBS_DIR@", config.environment.get(shlibpath_var, ""))
+    (config.shlibdir, config.llvm_libs_dir, config.environment.get(shlibpath_var, ""))
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kikairoya wrote:

`@SHLIBDIR@` is replaced by CMake's configuration function, so it must be in `lit.site.cfg.py.in` but not `lit.cfg.py`.
`lit.cfg.py` must reference variables in generated `lit.site.cfg.py`.

https://github.com/kikairoya/llvm-project/blob/efac315751bb086490a64e68e17fc9cc38afe328/clang-tools-extra/clangd/unittests/lit.site.cfg.py.in#L4-L5

https://github.com/kikairoya/llvm-project/blob/efac315751bb086490a64e68e17fc9cc38afe328/clang-tools-extra/clangd/unittests/CMakeLists.txt#L200-L202

https://github.com/llvm/llvm-project/pull/163947