[LIT][Cygwin] Mark ulimit -n unsupported for Cygwin

[kikairoya]

Cygwin doesn't support ulimit -n because Windows doesn't provide such functionality.

[llvmbot]

@llvm/pr-subscribers-testing-tools

Author: Tomohiro Kashiwada (kikairoya)

Changes

Cygwin doesn't support ulimit -n because Windows doesn't provide such functionality.

---

Full diff: https://github.com/llvm/llvm-project/pull/164604.diff

2 Files Affected:

• (modified) llvm/utils/lit/lit/run.py (+2-2)
• (modified) llvm/utils/lit/tests/shtest-ulimit.py (+1-1)

diff --git a/llvm/utils/lit/lit/run.py b/llvm/utils/lit/lit/run.py
index 62070e824e87f..5830b21be6b0f 100644
--- a/llvm/utils/lit/lit/run.py
+++ b/llvm/utils/lit/lit/run.py
@@ -137,6 +137,6 @@ def _increase_process_limit(self):
                     "Raised process limit from %d to %d" % (soft_limit, desired_limit)
                 )
         except Exception as ex:
-            # Warn, unless this is Windows or z/OS, in which case this is expected.
-            if os.name != "nt" and platform.system() != "OS/390":
+            # Warn, unless this is Windows, z/OS, or Cygwin in which case this is expected.
+            if os.name != "nt" and platform.system() != "OS/390" and platform.sys.platform != "cygwin":
                 self.lit_config.warning("Failed to raise process limit: %s" % ex)
diff --git a/llvm/utils/lit/tests/shtest-ulimit.py b/llvm/utils/lit/tests/shtest-ulimit.py
index 9a8febd3333c4..c3d51067e8936 100644
--- a/llvm/utils/lit/tests/shtest-ulimit.py
+++ b/llvm/utils/lit/tests/shtest-ulimit.py
@@ -3,7 +3,7 @@
 # ulimit does not work on non-POSIX platforms.
 # Solaris for some reason does not respect ulimit -n, so mark it unsupported
 # as well.
-# UNSUPPORTED: system-windows, system-solaris
+# UNSUPPORTED: system-windows, system-cygwin, system-solaris
 
 # RUN: not %{lit} -a -v %{inputs}/shtest-ulimit --order=lexical | FileCheck %s
 

[kikairoya]

cc: @jeremyd2019 @mstorsjo

[github-actions]

✅ With the latest revision this PR passed the Python code formatter.

[mstorsjo]

LGTM

[llvm-ci]

LLVM Buildbot has detected a new failure on builder ppc64le-flang-rhel-clang running on ppc64le-flang-rhel-test while building llvm at step 6 "test-build-unified-tree-check-flang".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/157/builds/41678

Here is the relevant piece of the build log for the reference

Step 6 (test-build-unified-tree-check-flang) failure: 1200 seconds without output running [b'ninja', b'check-flang'], attempting to kill
11.743 [4/29/0] cd /home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/build/runtimes/runtimes-bins && /home/buildbots/llvm-external-buildbots/cmake-3.31.2/bin/cmake --build /home/buildbots/llvm-external-buildbots/workers/ppc64le-flang-rhel-test/ppc64le-flang-rhel-clang-build/build/runtimes/runtimes-bins/ --target libomp-mod --config Release
ninja: no work to do.
12.071 [2/4/28] Building CXX object tools/flang/unittests/Frontend/CMakeFiles/FlangFrontendTests.dir/FrontendActionTest.cpp.o
12.533 [1/3/30] Linking CXX executable tools/flang/unittests/Common/FlangCommonTests
17.538 [1/2/31] Linking CXX executable tools/flang/unittests/Optimizer/FlangOptimizerTests
25.931 [1/1/32] Linking CXX executable tools/flang/unittests/Frontend/FlangFrontendTests
25.932 [0/1/32] Running the Flang regression tests
command timed out: 1200 seconds without output running [b'ninja', b'check-flang'], attempting to kill
process killed by signal 9
program finished with exit code -1
elapsedTime=1226.732348