[libc++] Cherry-pick the disabling of modules tests onto release/18.x

[ldionne]

LIT was never really meant to generate tests during discovery, and we probably shouldn't be doing this.

This hack is even worse than the initial attempt because it buries the "UNSUPPORTED" at the bottom of the test.

Fixes #85242

[llvmbot]

@llvm/pr-subscribers-libcxx

Author: Louis Dionne (ldionne)

Changes

LIT was never really meant to generate tests during discovery, and we probably shouldn't be doing this.

This hack is even worse than the initial attempt because it buries the "UNSUPPORTED" at the bottom of the test.

Fixes #85242

---

Full diff: https://github.com/llvm/llvm-project/pull/85247.diff

2 Files Affected:

• (modified) libcxx/test/libcxx/module_std.gen.py (+5)
• (modified) libcxx/test/libcxx/module_std_compat.gen.py (+5)

diff --git a/libcxx/test/libcxx/module_std.gen.py b/libcxx/test/libcxx/module_std.gen.py
index a9a05a0cd74e61..3bc6ddbd882031 100644
--- a/libcxx/test/libcxx/module_std.gen.py
+++ b/libcxx/test/libcxx/module_std.gen.py
@@ -16,7 +16,11 @@
 # to be one monolitic test. Since the test doesn't take very long it's
 # not a huge issue.
 
+# WARNING: Disabled at the bottom. Fix this test and remove the UNSUPPORTED line
+# TODO: Re-enable this test once we understand why it keeps timing out.
+
 # RUN: %{python} %s %{libcxx}/utils
+# END.
 
 import sys
 
@@ -35,4 +39,5 @@
 
 
 print("//--- module_std.sh.cpp")
+print('// UNSUPPORTED: clang')
 generator.write_test("std")
diff --git a/libcxx/test/libcxx/module_std_compat.gen.py b/libcxx/test/libcxx/module_std_compat.gen.py
index 270d131779e5bf..c1e74eb379c8ab 100644
--- a/libcxx/test/libcxx/module_std_compat.gen.py
+++ b/libcxx/test/libcxx/module_std_compat.gen.py
@@ -16,7 +16,11 @@
 # to be one monolitic test. Since the test doesn't take very long it's
 # not a huge issue.
 
+# WARNING: Disabled at the bottom. Fix this test and remove the UNSUPPORTED line
+# TODO: Re-enable this test once we understand why it keeps timing out.
+
 # RUN: %{python} %s %{libcxx}/utils
+# END.
 
 import sys
 
@@ -36,6 +40,7 @@
 
 
 print("//--- module_std_compat.sh.cpp")
+print("// UNSUPPORTED: clang")
 generator.write_test(
     "std.compat",
     module_c_headers,

[mordante]

I'd rather fix the clang-tidy integration. I'm quite sure we have ODR violations since we use clang-tidy 18 with clang 17 libraries. These violations break the modules, but other clang-tidy checks may also have issues. Changing https://github.com/llvm/llvm-project/blob/release/18.x/libcxx/test/tools/clang_tidy_checks/CMakeLists.txt#L8 to 18.1 likely fixes the issue.

I forgot about the release branch when I fixed this in main.

[ldionne]

@mordante So should I close this PR?

[mordante]

@mordante So should I close this PR?

I see you already did. Do you want to make a fix for the release branch or do you want me to pick that up?

[ldionne]

Is the fix only to switch to 18.1 in the cmake? I can do that if that's it, I just don't fully understand the situation w/ clang tidy ODR violations since you were the one to make these changes

[mordante]

Is the fix only to switch to 18.1 in the cmake? I can do that if that's it, I just don't fully understand the situation w/ clang tidy ODR violations since you were the one to make these changes

That should be all. I'm also happy to do it, but that will be tomorrow.

[ldionne]

No worries! I just created #85305, hopefully that should do the trick.