MLIR: asan: Fix python tests under asan on Linux

[mgehre-amd]

Running MLIR python tests unders asan currently fails with

executed command: 'LD_PRELOAD=$(/usr/bin/clang++-17' '-print-file-name=libclang_rt.asan-x86_64.so)' /scratch/slx-llvm/.venv-3.10/bin/python3.10 /scratch/slx-llvm/mlir/test/python/ir/context_lifecycle.py

| 'LD_PRELOAD=$(/usr/bin/clang++-17': command not found

because lit doesn't quite understand the syntax.
To fix, we resolve the path to libclang_rt.asan-x86_64.so within the lit configuration. This has the additional benefit that we don't have to call clang++ for every test.

[llvmbot]

@llvm/pr-subscribers-mlir

Author: Matthias Gehre (mgehre-amd)

Changes

Running MLIR python tests unders asan currently fails with

because lit doesn't quite understand the syntax.
To fix, we resolve the path to libclang_rt.asan-x86_64.so within the lit configuration. This has the additional benefit that we don't have to call clang++ for every test.

---

Full diff: https://github.com/llvm/llvm-project/pull/123303.diff

1 Files Affected:

• (modified) mlir/test/lit.cfg.py (+28-11)

diff --git a/mlir/test/lit.cfg.py b/mlir/test/lit.cfg.py
index c28623123d9991..3122214be73f18 100644
--- a/mlir/test/lit.cfg.py
+++ b/mlir/test/lit.cfg.py
@@ -82,17 +82,32 @@ def add_runtime(name):
 # available. This is darwin specific since it's currently only needed on darwin.
 # Stolen from llvm/test/lit.cfg.py with a few modifications
 def get_asan_rtlib():
-    if not "asan" in config.available_features or not "Darwin" in config.host_os:
+    if not "asan" in config.available_features:
         return ""
-    # Find the asan rt lib
-    resource_dir = (
-        subprocess.check_output([config.host_cc.strip(), "-print-resource-dir"])
-        .decode("utf-8")
-        .strip()
-    )
-    return os.path.join(
-        resource_dir, "lib", "darwin", "libclang_rt.asan_osx_dynamic.dylib"
-    )
+
+    if "Darwin" in config.host_os:
+        # Find the asan rt lib
+        resource_dir = (
+            subprocess.check_output([config.host_cc.strip(), "-print-resource-dir"])
+            .decode("utf-8")
+            .strip()
+        )
+        return os.path.join(
+            resource_dir, "lib", "darwin", "libclang_rt.asan_osx_dynamic.dylib"
+        )
+    if "Linux" in config.host_os:
+        return (
+            subprocess.check_output(
+                [
+                    config.host_cxx.strip(),
+                    f"-print-file-name=libclang_rt.asan-{config.host_arch}.so",
+                ]
+            )
+            .decode("utf-8")
+            .strip()
+        )
+
+    return ""
 
 
 # On macOS, we can't do the DYLD_INSERT_LIBRARIES trick with a shim python
@@ -247,7 +262,9 @@ def find_real_python_interpreter():
 # TODO: detect Windows situation (or mark these tests as unsupported on these platforms).
 if "asan" in config.available_features:
     if "Linux" in config.host_os:
-        python_executable = f"LD_PRELOAD=$({config.host_cxx} -print-file-name=libclang_rt.asan-{config.host_arch}.so) {config.python_executable}"
+        python_executable = (
+            f"env LD_PRELOAD={find_asan_runtime()} {config.python_executable}"
+        )
     if "Darwin" in config.host_os:
         # Ensure we use a non-shim Python executable, for the `DYLD_INSERT_LIBRARIES`
         # env variable to take effect

[makslevental]

Cool thanks - this is a very useful improvement because I'm always wanting to run under ASAN but never had the patience to figure out this failure.