[compiler-rt] [llvm] [lit] [compiler-rt] Add llvm-lit global command cache to speed up test config (PR #195888)
Andrew Haberlandt via llvm-commits
llvm-commits at lists.llvm.org
Tue May 5 12:04:00 PDT 2026
https://github.com/ndrewh updated https://github.com/llvm/llvm-project/pull/195888
>From 335aafcc84be71c646fd0c38abb1b10cad00544f Mon Sep 17 00:00:00 2001
From: Andrew Haberlandt <ahaberlandt at apple.com>
Date: Tue, 5 May 2026 10:32:23 -0700
Subject: [PATCH 1/3] [lit] [compiler-rt] Add llvm-lit global command cache to
speed up test config
Compiler-rt lit test discovery takes quite a while on Darwin (i.e.
the time from when you launch llvm-lit to when the first test runs
can be minutes for check-compiler-rt). This appears to be mostly due
to subprocess calls during test configuration.
This adds a memoized command-runner to llvm-lit, so that lit.cfg.py
scripts can re-use the result of feature-detection commands when
running multiple test suites at once.
rdar://175893448
---
compiler-rt/test/lit.common.cfg.py | 39 +++++++-----------------------
llvm/utils/lit/lit/util.py | 25 ++++++++++++++++++-
2 files changed, 33 insertions(+), 31 deletions(-)
diff --git a/compiler-rt/test/lit.common.cfg.py b/compiler-rt/test/lit.common.cfg.py
index fef8f7ab297cc..b6eb8c08578fb 100644
--- a/compiler-rt/test/lit.common.cfg.py
+++ b/compiler-rt/test/lit.common.cfg.py
@@ -20,20 +20,8 @@ def get_path_from_clang(args, allow_failure):
f"--target={config.target_triple}",
*args,
]
- path = None
- try:
- result = subprocess.run(
- clang_cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, check=True
- )
- path = result.stdout.decode().strip()
- except subprocess.CalledProcessError as e:
- msg = f"Failed to run {clang_cmd}\nrc:{e.returncode}\nstdout:{e.stdout}\ne.stderr{e.stderr}"
- if allow_failure:
- lit_config.warning(msg)
- else:
- lit_config.fatal(msg)
- return path, clang_cmd
-
+ path = lit.util.runCommandCached(clang_cmd, allow_failure, text=True)
+ return path.strip(), clang_cmd
def find_compiler_libdir():
"""
@@ -592,10 +580,10 @@ def get_ios_commands_dir():
# There is no simulator-specific sw_vers/sysctl, so we use the host OS version
os_detection_prefix = []
- darwin_os_version = subprocess.check_output(
- os_detection_prefix + ["sw_vers", "-productVersion"], universal_newlines=True
+ darwin_os_version = lit.util.runCommandCached(
+ os_detection_prefix + ["sw_vers", "-productVersion"], universal_newlines=True, text=True
)
- darwin_os_version = tuple(int(x) for x in darwin_os_version.split("."))
+ darwin_os_version = tuple(int(x) for x in darwin_os_version.strip().split("."))
if len(darwin_os_version) == 2:
darwin_os_version = (darwin_os_version[0], darwin_os_version[1], 0)
@@ -609,8 +597,8 @@ def get_ios_commands_dir():
# Detect x86_64h
try:
- output = subprocess.check_output(
- os_detection_prefix + ["sysctl", "hw.cpusubtype"]
+ output = lit.util.runCommandCached(
+ os_detection_prefix + ["sysctl", "hw.cpusubtype"], text=True
)
output_re = re.match("^hw.cpusubtype: ([0-9]+)$", output)
if output_re:
@@ -955,18 +943,9 @@ def is_windows_lto_supported():
if lit.util.which("log"):
# Querying the log can only done by a privileged user so
# so check if we can query the log.
- exit_code = -1
- with open("/dev/null", "r") as f:
- # Run a `log show` command the should finish fairly quickly and produce very little output.
- exit_code = subprocess.call(
- ["log", "show", "--last", "1m", "--predicate", "1 == 0"],
- stdout=f,
- stderr=f,
- )
- if exit_code == 0:
+ res = lit.util.runCommandCached(["log", "show", "--last", "1m", "--predicate", "1 == 0"], allow_failure=True)
+ if res is not None:
config.available_features.add("darwin_log_cmd")
- else:
- lit_config.warning("log command found but cannot queried")
else:
lit_config.warning("log command not found. Some tests will be skipped.")
elif config.android:
diff --git a/llvm/utils/lit/lit/util.py b/llvm/utils/lit/lit/util.py
index a800f1f6e1419..8fd296f460a02 100644
--- a/llvm/utils/lit/lit/util.py
+++ b/llvm/utils/lit/lit/util.py
@@ -12,7 +12,7 @@
import subprocess
import sys
import threading
-
+import functools
def pythonize_bool(value):
if value is None:
@@ -441,3 +441,26 @@ def killProcessAndChildren(pid):
psutilProc.kill()
except psutil.NoSuchProcess:
pass
+
+ at functools.cache
+def _runCommandCachedInner(cmd, allow_failure, **kwargs):
+ try:
+ result = subprocess.run(
+ cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, check=True, **kwargs
+ )
+ return result.stdout
+ except subprocess.CalledProcessError as e:
+ msg = f"Failed to run {cmd}\nrc:{e.returncode}\nstdout:{e.stdout}\ne.stderr{e.stderr}"
+ if allow_failure:
+ lit_config.warning(msg)
+ else:
+ lit_config.fatal(msg)
+ return None
+
+def runCommandCached(cmd, allow_failure=False, **kwargs):
+ if type(cmd) is list:
+ cmd = tuple(cmd)
+ elif type(cmd) is str:
+ cmd = tuple([cmd])
+
+ return _runCommandCachedInner(cmd, allow_failure, **kwargs)
>From 4989f240098009812b585febf27a947afb7f2d7b Mon Sep 17 00:00:00 2001
From: Andrew Haberlandt <ahaberlandt at apple.com>
Date: Tue, 5 May 2026 10:45:34 -0700
Subject: [PATCH 2/3] format
---
compiler-rt/test/lit.common.cfg.py | 8 ++++++--
llvm/utils/lit/lit/util.py | 2 ++
2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/compiler-rt/test/lit.common.cfg.py b/compiler-rt/test/lit.common.cfg.py
index b6eb8c08578fb..37534fcd8dba8 100644
--- a/compiler-rt/test/lit.common.cfg.py
+++ b/compiler-rt/test/lit.common.cfg.py
@@ -581,7 +581,9 @@ def get_ios_commands_dir():
os_detection_prefix = []
darwin_os_version = lit.util.runCommandCached(
- os_detection_prefix + ["sw_vers", "-productVersion"], universal_newlines=True, text=True
+ os_detection_prefix + ["sw_vers", "-productVersion"],
+ universal_newlines=True,
+ text=True,
)
darwin_os_version = tuple(int(x) for x in darwin_os_version.strip().split("."))
@@ -943,7 +945,9 @@ def is_windows_lto_supported():
if lit.util.which("log"):
# Querying the log can only done by a privileged user so
# so check if we can query the log.
- res = lit.util.runCommandCached(["log", "show", "--last", "1m", "--predicate", "1 == 0"], allow_failure=True)
+ res = lit.util.runCommandCached(
+ ["log", "show", "--last", "1m", "--predicate", "1 == 0"], allow_failure=True
+ )
if res is not None:
config.available_features.add("darwin_log_cmd")
else:
diff --git a/llvm/utils/lit/lit/util.py b/llvm/utils/lit/lit/util.py
index 8fd296f460a02..35de0d1176e05 100644
--- a/llvm/utils/lit/lit/util.py
+++ b/llvm/utils/lit/lit/util.py
@@ -442,6 +442,7 @@ def killProcessAndChildren(pid):
except psutil.NoSuchProcess:
pass
+
@functools.cache
def _runCommandCachedInner(cmd, allow_failure, **kwargs):
try:
@@ -457,6 +458,7 @@ def _runCommandCachedInner(cmd, allow_failure, **kwargs):
lit_config.fatal(msg)
return None
+
def runCommandCached(cmd, allow_failure=False, **kwargs):
if type(cmd) is list:
cmd = tuple(cmd)
>From 756dfb44dbdedf02f474cc92304ad6deb7cea9b4 Mon Sep 17 00:00:00 2001
From: Andrew Haberlandt <ahaberlandt at apple.com>
Date: Tue, 5 May 2026 12:02:14 -0700
Subject: [PATCH 3/3] Feedback + add helper on LitCOnfig
---
compiler-rt/test/lit.common.cfg.py | 16 +++--
llvm/utils/lit/lit/LitConfig.py | 16 +++++
llvm/utils/lit/lit/util.py | 24 ++++----
llvm/utils/lit/tests/unit/Util.py | 94 ++++++++++++++++++++++++++++++
4 files changed, 128 insertions(+), 22 deletions(-)
create mode 100644 llvm/utils/lit/tests/unit/Util.py
diff --git a/compiler-rt/test/lit.common.cfg.py b/compiler-rt/test/lit.common.cfg.py
index 37534fcd8dba8..12446b4708d20 100644
--- a/compiler-rt/test/lit.common.cfg.py
+++ b/compiler-rt/test/lit.common.cfg.py
@@ -20,7 +20,7 @@ def get_path_from_clang(args, allow_failure):
f"--target={config.target_triple}",
*args,
]
- path = lit.util.runCommandCached(clang_cmd, allow_failure, text=True)
+ path = lit_config.run_command_cached(clang_cmd, allow_failure, text=True)
return path.strip(), clang_cmd
def find_compiler_libdir():
@@ -580,7 +580,7 @@ def get_ios_commands_dir():
# There is no simulator-specific sw_vers/sysctl, so we use the host OS version
os_detection_prefix = []
- darwin_os_version = lit.util.runCommandCached(
+ darwin_os_version = lit_config.run_command_cached(
os_detection_prefix + ["sw_vers", "-productVersion"],
universal_newlines=True,
text=True,
@@ -598,17 +598,15 @@ def get_ios_commands_dir():
config.darwin_os_version = darwin_os_version
# Detect x86_64h
- try:
- output = lit.util.runCommandCached(
- os_detection_prefix + ["sysctl", "hw.cpusubtype"], text=True
- )
+ output = lit_config.run_command_cached(
+ os_detection_prefix + ["sysctl", "hw.cpusubtype"], text=True, allow_failure=True
+ )
+ if output:
output_re = re.match("^hw.cpusubtype: ([0-9]+)$", output)
if output_re:
cpu_subtype = int(output_re.group(1))
if cpu_subtype == 8: # x86_64h
config.available_features.add("x86_64h")
- except:
- pass
# 32-bit iOS simulator is deprecated and removed in latest Xcode.
if config.apple_platform == "iossim":
@@ -945,7 +943,7 @@ def is_windows_lto_supported():
if lit.util.which("log"):
# Querying the log can only done by a privileged user so
# so check if we can query the log.
- res = lit.util.runCommandCached(
+ res = lit_config.run_command_cached(
["log", "show", "--last", "1m", "--predicate", "1 == 0"], allow_failure=True
)
if res is not None:
diff --git a/llvm/utils/lit/lit/LitConfig.py b/llvm/utils/lit/lit/LitConfig.py
index 3b0dfaa981d4a..4be2a0f6d8121 100644
--- a/llvm/utils/lit/lit/LitConfig.py
+++ b/llvm/utils/lit/lit/LitConfig.py
@@ -263,6 +263,22 @@ def fatal(self, message):
self._write_message("fatal", message)
sys.exit(2)
+ def run_command_cached(self, cmd, allow_failure=False, **kwargs):
+ """
+ Run a command with subprocess.run, with a cache global to this llvm-lit invocation
+ If allow_failure is True, lit_config.fatal will be invoked if the command fails.
+ All additional kwargs are passed to subprocess.run
+ """
+ if type(cmd) is list:
+ cmd = tuple(cmd)
+ return lit.util.runCommandCached(self, cmd, allow_failure, **kwargs)
+ elif type(cmd) is str:
+ return lit.util.runCommandCached(self, cmd, allow_failure, **kwargs)
+ else:
+ raise ValueError(
+ f"runCommandCached expected list or str, got {type(cmd)}: {cmd}"
+ )
+
@enum.unique
class DiagnosticLevel(enum.IntEnum):
diff --git a/llvm/utils/lit/lit/util.py b/llvm/utils/lit/lit/util.py
index 35de0d1176e05..13eea2045242e 100644
--- a/llvm/utils/lit/lit/util.py
+++ b/llvm/utils/lit/lit/util.py
@@ -444,25 +444,23 @@ def killProcessAndChildren(pid):
@functools.cache
-def _runCommandCachedInner(cmd, allow_failure, **kwargs):
+def runCommandCached(lit_config, cmd, allow_failure, **kwargs):
+ """
+ Run a command with subprocess.run, with a cache global to this llvm-lit invocation
+ If allow_failure is True, lit_config.fatal will be invoked if the command fails.
+ All additional kwargs are passed to subprocess.run
+ """
try:
result = subprocess.run(
cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, check=True, **kwargs
)
return result.stdout
+ except FileNotFoundError as e:
+ msg = f"Failed to run {cmd}: {e}"
except subprocess.CalledProcessError as e:
msg = f"Failed to run {cmd}\nrc:{e.returncode}\nstdout:{e.stdout}\ne.stderr{e.stderr}"
- if allow_failure:
- lit_config.warning(msg)
- else:
- lit_config.fatal(msg)
- return None
+ if not allow_failure:
+ lit_config.fatal(msg)
-def runCommandCached(cmd, allow_failure=False, **kwargs):
- if type(cmd) is list:
- cmd = tuple(cmd)
- elif type(cmd) is str:
- cmd = tuple([cmd])
-
- return _runCommandCachedInner(cmd, allow_failure, **kwargs)
+ return None
diff --git a/llvm/utils/lit/tests/unit/Util.py b/llvm/utils/lit/tests/unit/Util.py
new file mode 100644
index 0000000000000..a84092c9cdc7a
--- /dev/null
+++ b/llvm/utils/lit/tests/unit/Util.py
@@ -0,0 +1,94 @@
+# RUN: %{python} %s
+# UNSUPPORTED: system-windows
+
+import unittest
+import platform
+import time
+
+from lit.util import runCommandCached
+from lit.LitConfig import LitConfig
+
+
+class TestCommandCache(unittest.TestCase):
+ @staticmethod
+ def _lit_config():
+ return LitConfig(
+ progname="lit",
+ path=[],
+ diagnostic_level="note",
+ useValgrind=False,
+ valgrindLeakCheck=False,
+ valgrindArgs=[],
+ noExecute=False,
+ debug=False,
+ isWindows=(platform.system() == "Windows"),
+ order="smart",
+ params={},
+ )
+
+ def test_basic(self):
+ lit_config = self._lit_config()
+
+ self.assertEqual(lit_config.run_command_cached(["echo", "-n", "hi"]), b"hi")
+ self.assertNotEqual(lit_config.run_command_cached("ls"), None)
+
+ # Test that arguments (e.g. text=True) get forwarded to subprocess.run
+ self.assertEqual(
+ lit_config.run_command_cached(["echo", "-n", "hi"], text=True), "hi"
+ )
+
+ # shell=True is not implied
+ self.assertEqual(
+ lit_config.run_command_cached("ls -al", allow_failure=True), None
+ )
+ self.assertNotEqual(
+ lit_config.run_command_cached("ls -al", allow_failure=True, shell=True),
+ None,
+ )
+
+ self.assertEqual(
+ lit_config.run_command_cached("exit 0", shell=True, allow_failure=True), b""
+ )
+
+ def test_fatal(self):
+ lit_config = self._lit_config()
+
+ # Test fatal errors
+ fatal_counter = 0
+
+ def wrap_fatal(msg):
+ nonlocal fatal_counter
+ fatal_counter += 1
+
+ lit_config.fatal = wrap_fatal
+ lit_config.run_command_cached(["asdfghjkl"])
+ self.assertEqual(fatal_counter, 1)
+
+ self.assertEqual(
+ lit_config.run_command_cached(["asdfghjkl"], allow_failure=True), None
+ )
+ self.assertEqual(
+ lit_config.run_command_cached("exit 1", shell=True, allow_failure=True),
+ None,
+ )
+ self.assertEqual(fatal_counter, 1)
+
+ def test_cache(self):
+ lit_config = self._lit_config()
+
+ t1 = time.time()
+ self.assertNotEqual(lit_config.run_command_cached("sleep 1", shell=True), None)
+ t2 = time.time()
+ self.assertGreater(t2 - t1, 0.5)
+
+ # Second time should be cached
+ t1 = time.time()
+ self.assertNotEqual(lit_config.run_command_cached("sleep 1", shell=True), None)
+ t2 = time.time()
+
+ # The second run should be instant
+ self.assertLess(t2 - t1, 0.5)
+
+
+if __name__ == "__main__":
+ unittest.main()
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