[llvm-branch-commits] [libcxx] [libc++] Adds is_implemented function for new ftm generator. (PR #134538)
Mark de Wever via llvm-branch-commits
llvm-branch-commits at lists.llvm.org
Sun Apr 6 06:35:49 PDT 2025
https://github.com/mordante created https://github.com/llvm/llvm-project/pull/134538
At the moment the ftm macro for __cpp_lib_to_chars will have the following values:
standard_ftms: {
"c++17": "201611L",
"c++20": "201611L",
"c++23": "201611L",
"c++26": "201611L",
}
implemented_ftms: {
"c++17": None,
}
This is an issue with the test whether the FTM is implemented it does:
self.implemented_ftms[ftm][std] == self.standard_ftms[ftm][std]
This will fail in C++20 since implemented_ftms[ftm] does not have the key c++20. This adds a new helper function and removes the None entries when a FTM is not implemented.
>From 72954e170f2c91c10d4dd4702db981a7b8c756fc Mon Sep 17 00:00:00 2001
From: Mark de Wever <koraq at xs4all.nl>
Date: Sat, 5 Apr 2025 12:15:09 +0200
Subject: [PATCH] [libc++] Adds is_implemented function for new ftm generator.
At the moment the ftm macro for __cpp_lib_to_chars will have the
following values:
standard_ftms: {
"c++17": "201611L",
"c++20": "201611L",
"c++23": "201611L",
"c++26": "201611L",
}
implemented_ftms: {
"c++17": None,
}
This is an issue with the test whether the FTM is implemented it does:
self.implemented_ftms[ftm][std] == self.standard_ftms[ftm][std]
This will fail in C++20 since implemented_ftms[ftm] does not have the
key c++20. This adds a new helper function and removes the None entries
when a FTM is not implemented.
---
.../feature_test_macro/implemented_ftms.sh.py | 12 +-----
.../feature_test_macro/is_implemented.sh.py | 39 +++++++++++++++++++
.../generate_feature_test_macro_components.py | 19 ++++++++-
3 files changed, 58 insertions(+), 12 deletions(-)
create mode 100644 libcxx/test/libcxx/feature_test_macro/is_implemented.sh.py
diff --git a/libcxx/test/libcxx/feature_test_macro/implemented_ftms.sh.py b/libcxx/test/libcxx/feature_test_macro/implemented_ftms.sh.py
index 92e14757ddd49..4f445d55c883c 100644
--- a/libcxx/test/libcxx/feature_test_macro/implemented_ftms.sh.py
+++ b/libcxx/test/libcxx/feature_test_macro/implemented_ftms.sh.py
@@ -38,11 +38,7 @@ def test_implementation(self):
"c++23": "201907L",
"c++26": "299900L",
},
- "__cpp_lib_format": {
- "c++20": None,
- "c++23": None,
- "c++26": None,
- },
+ "__cpp_lib_format": {},
"__cpp_lib_parallel_algorithm": {
"c++17": "201603L",
"c++20": "201603L",
@@ -55,11 +51,7 @@ def test_implementation(self):
"c++23": "202102L",
"c++26": "202102L",
},
- "__cpp_lib_missing_FTM_in_older_standard": {
- "c++17": None,
- "c++20": None,
- "c++26": None,
- },
+ "__cpp_lib_missing_FTM_in_older_standard": {},
}
self.assertEqual(self.ftm.implemented_ftms, expected)
diff --git a/libcxx/test/libcxx/feature_test_macro/is_implemented.sh.py b/libcxx/test/libcxx/feature_test_macro/is_implemented.sh.py
new file mode 100644
index 0000000000000..0414722b89a76
--- /dev/null
+++ b/libcxx/test/libcxx/feature_test_macro/is_implemented.sh.py
@@ -0,0 +1,39 @@
+# ===----------------------------------------------------------------------===##
+#
+# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+#
+# ===----------------------------------------------------------------------===##
+
+# RUN: %{python} %s %{libcxx-dir}/utils %{libcxx-dir}/test/libcxx/feature_test_macro/test_data.json
+
+import sys
+import unittest
+
+UTILS = sys.argv[1]
+TEST_DATA = sys.argv[2]
+del sys.argv[1:3]
+
+sys.path.append(UTILS)
+from generate_feature_test_macro_components import FeatureTestMacros, Metadata
+
+
+class Test(unittest.TestCase):
+ def setUp(self):
+ self.ftm = FeatureTestMacros(TEST_DATA)
+ self.maxDiff = None # This causes the diff to be printed when the test fails
+
+ def test_implementation(self):
+ # FTM not available in C++14.
+ self.assertEqual(self.ftm.is_implemented("__cpp_lib_any", "c++14"), False)
+ self.assertEqual(self.ftm.is_implemented("__cpp_lib_any", "c++17"), True)
+
+ self.assertEqual(self.ftm.is_implemented("__cpp_lib_format", "c++20"), False)
+
+ # FTM C++20 202106L, libc++ has 202102L
+ self.assertEqual(self.ftm.is_implemented("__cpp_lib_variant", "c++20"), False)
+
+
+if __name__ == "__main__":
+ unittest.main()
diff --git a/libcxx/utils/generate_feature_test_macro_components.py b/libcxx/utils/generate_feature_test_macro_components.py
index 53252d5e2d673..ecf31f5af7fb2 100755
--- a/libcxx/utils/generate_feature_test_macro_components.py
+++ b/libcxx/utils/generate_feature_test_macro_components.py
@@ -2012,7 +2012,8 @@ def get_ftms(
else:
break
- entry[std] = last
+ if last:
+ entry[std] = last
result[feature["name"]] = entry
return result
@@ -2208,6 +2209,20 @@ def implemented_ftms(self) -> Dict[Ftm, Dict[Std, Optional[Value]]]:
return get_ftms(self.__data, self.std_dialects, True)
+ def is_implemented(self, ftm: Ftm, std: Std) -> bool:
+ """Has the FTM `ftm` been implemented in the dialect `std`?"""
+
+ # When a paper for C++20 has not been implemented in libc++, then there will be no
+ # FTM entry in implemented_ftms for C++23 and later.
+ #
+ # Typically standard_ftms is not used with invalid values in the code, but
+ # guard just in case.
+ if not std in self.implemented_ftms[ftm].keys() or not std in self.standard_ftms[ftm].keys():
+ return False
+
+ return self.implemented_ftms[ftm][std] == self.standard_ftms[ftm][std]
+
+
@functools.cached_property
def ftm_metadata(self) -> Dict[Ftm, Metadata]:
"""Returns the metadata of the FTMs defined in the Standard.
@@ -2241,7 +2256,7 @@ def version_header_implementation(self) -> Dict[Std, Dict[Ftm, VersionHeader]]:
continue
last_value = value
- implemented = self.implemented_ftms[ftm][std] == self.standard_ftms[ftm][std]
+ implemented = self.is_implemented(ftm, std)
entry = VersionHeader(
value,
implemented,
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