[libc++] Add missing %{flags} substitution to clang-tidy

[ldionne]

Flags that should be used both for compiling and for linking are provided through the %{flags} substitution. Our clang-tidy tests should be using them, not only %{compile_flags}.

[llvmbot]

@llvm/pr-subscribers-libcxx

Author: Louis Dionne (ldionne)

Changes

Flags that should be used both for compiling and for linking are provided through the %{flags} substitution. Our clang-tidy tests should be using them, not only %{compile_flags}.

---

Full diff: https://github.com/llvm/llvm-project/pull/171689.diff

1 Files Affected:

• (modified) libcxx/test/libcxx/clang_tidy.gen.py (+1-1)

diff --git a/libcxx/test/libcxx/clang_tidy.gen.py b/libcxx/test/libcxx/clang_tidy.gen.py
index 16c90c3ef7130..b46cc72c08dfd 100644
--- a/libcxx/test/libcxx/clang_tidy.gen.py
+++ b/libcxx/test/libcxx/clang_tidy.gen.py
@@ -27,7 +27,7 @@
 {lit_header_undeprecations.get(header, '')}
 
 // TODO: run clang-tidy with modules enabled once they are supported
-// RUN: %{{clang-tidy}} %s --warnings-as-errors=* -header-filter=.* --config-file=%{{libcxx-dir}}/.clang-tidy --load=%{{test-tools-dir}}/clang_tidy_checks/libcxx-tidy.plugin -- -Wweak-vtables %{{compile_flags}} -fno-modules
+// RUN: %{{clang-tidy}} %s --warnings-as-errors=* -header-filter=.* --config-file=%{{libcxx-dir}}/.clang-tidy --load=%{{test-tools-dir}}/clang_tidy_checks/libcxx-tidy.plugin -- -Wweak-vtables %{{flags}} %{{compile_flags}} -fno-modules
 
 #include <{header}>
 """)

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--- clang_tidy.gen.py	2025-12-11 17:32:36.000000 +0000
+++ clang_tidy.gen.py	2025-12-11 17:34:07.500648 +0000
@@ -32,6 +32,7 @@
 // RUN:                    --config-file=%{{libcxx-dir}}/.clang-tidy                        \\
 // RUN:                    --load=%{{test-tools-dir}}/clang_tidy_checks/libcxx-tidy.plugin  \\
 // RUN:                    -- -Wweak-vtables %{{flags}} %{{compile_flags}} -fno-modules
 
 #include <{header}>
-""")
+"""
+    )

[philnik777]

FWIW IMO %{flags} is a bad name here. I expected %{compile_flags} to contain all flags that should be used when compiling, %{link_flags} to contain all flags that should be used when linking, and %{flags} to contain all flags that should be used when compiling and linking in one command.

[ldionne]

FWIW IMO %{flags} is a bad name here. I expected %{compile_flags} to contain all flags that should be used when compiling, %{link_flags} to contain all flags that should be used when linking, and %{flags} to contain all flags that should be used when compiling and linking in one command.

Perhaps %{common_flags} would be a better name?

[philnik777]

Yeah, I think so.