[libc][bazel] simplify type_traits with glob

[michaelrj-google]

Previously the type_traits target manually listed all of the type
traits files. This patch replaces that with a glob to make the build
simpler.

[llvmbot]

@llvm/pr-subscribers-libc

Author: Michael Jones (michaelrj-google)

Changes

Previously the type_traits target manually listed all of the type
traits files. This patch replaces that with a glob to make the build
simpler.

---

Full diff: https://github.com/llvm/llvm-project/pull/94079.diff

1 Files Affected:

• (modified) utils/bazel/llvm-project-overlay/libc/BUILD.bazel (+3-59)

diff --git a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
index 1f7a2f8a9f9fd..ff58fe6849c39 100644
--- a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
@@ -397,59 +397,8 @@ libc_support_library(
 
 libc_support_library(
     name = "__support_cpp_type_traits",
-    hdrs = [
+    hdrs = glob(["src/__support/CPP/type_traits/*.h"]) + [
         "src/__support/CPP/type_traits.h",
-        "src/__support/CPP/type_traits/add_lvalue_reference.h",
-        "src/__support/CPP/type_traits/add_pointer.h",
-        "src/__support/CPP/type_traits/add_rvalue_reference.h",
-        "src/__support/CPP/type_traits/always_false.h",
-        "src/__support/CPP/type_traits/bool_constant.h",
-        "src/__support/CPP/type_traits/conditional.h",
-        "src/__support/CPP/type_traits/decay.h",
-        "src/__support/CPP/type_traits/enable_if.h",
-        "src/__support/CPP/type_traits/false_type.h",
-        "src/__support/CPP/type_traits/integral_constant.h",
-        "src/__support/CPP/type_traits/invoke.h",
-        "src/__support/CPP/type_traits/invoke_result.h",
-        "src/__support/CPP/type_traits/is_arithmetic.h",
-        "src/__support/CPP/type_traits/is_array.h",
-        "src/__support/CPP/type_traits/is_base_of.h",
-        "src/__support/CPP/type_traits/is_class.h",
-        "src/__support/CPP/type_traits/is_const.h",
-        "src/__support/CPP/type_traits/is_constant_evaluated.h",
-        "src/__support/CPP/type_traits/is_convertible.h",
-        "src/__support/CPP/type_traits/is_destructible.h",
-        "src/__support/CPP/type_traits/is_enum.h",
-        "src/__support/CPP/type_traits/is_fixed_point.h",
-        "src/__support/CPP/type_traits/is_floating_point.h",
-        "src/__support/CPP/type_traits/is_function.h",
-        "src/__support/CPP/type_traits/is_integral.h",
-        "src/__support/CPP/type_traits/is_lvalue_reference.h",
-        "src/__support/CPP/type_traits/is_member_pointer.h",
-        "src/__support/CPP/type_traits/is_null_pointer.h",
-        "src/__support/CPP/type_traits/is_object.h",
-        "src/__support/CPP/type_traits/is_pointer.h",
-        "src/__support/CPP/type_traits/is_reference.h",
-        "src/__support/CPP/type_traits/is_rvalue_reference.h",
-        "src/__support/CPP/type_traits/is_same.h",
-        "src/__support/CPP/type_traits/is_scalar.h",
-        "src/__support/CPP/type_traits/is_signed.h",
-        "src/__support/CPP/type_traits/is_trivially_constructible.h",
-        "src/__support/CPP/type_traits/is_trivially_copyable.h",
-        "src/__support/CPP/type_traits/is_trivially_destructible.h",
-        "src/__support/CPP/type_traits/is_union.h",
-        "src/__support/CPP/type_traits/is_unsigned.h",
-        "src/__support/CPP/type_traits/is_void.h",
-        "src/__support/CPP/type_traits/make_signed.h",
-        "src/__support/CPP/type_traits/make_unsigned.h",
-        "src/__support/CPP/type_traits/remove_all_extents.h",
-        "src/__support/CPP/type_traits/remove_cv.h",
-        "src/__support/CPP/type_traits/remove_cvref.h",
-        "src/__support/CPP/type_traits/remove_extent.h",
-        "src/__support/CPP/type_traits/remove_reference.h",
-        "src/__support/CPP/type_traits/true_type.h",
-        "src/__support/CPP/type_traits/type_identity.h",
-        "src/__support/CPP/type_traits/void_t.h",
         "src/__support/CPP/utility/declval.h",
         "src/__support/CPP/utility/forward.h",
     ],
@@ -462,13 +411,8 @@ libc_support_library(
 
 libc_support_library(
     name = "__support_cpp_utility",
-    hdrs = [
+    hdrs = glob(["src/__support/CPP/utility/*.h"]) + [
         "src/__support/CPP/utility.h",
-        "src/__support/CPP/utility/declval.h",
-        "src/__support/CPP/utility/forward.h",
-        "src/__support/CPP/utility/in_place.h",
-        "src/__support/CPP/utility/integer_sequence.h",
-        "src/__support/CPP/utility/move.h",
     ],
     deps = [
         ":__support_cpp_type_traits",
@@ -640,8 +584,8 @@ libc_support_library(
     deps = [
         ":__support_integer_to_string",
         ":__support_macros_attributes",
-        ":__support_osutil_io",
         ":__support_osutil_exit",
+        ":__support_osutil_io",
     ],
 )
 

[jhuber6]

I know in CMake globs are problematic because adding a new file to the directory doesn't trigger a rebuild. However I'm assuming Bazel doesn't carry the same limitations and it's probably not an issue for headers.

[rupprecht]

I know in CMake globs are problematic because adding a new file to the directory doesn't trigger a rebuild. However I'm assuming Bazel doesn't carry the same limitations and it's probably not an issue for headers.

Yes, this is fine. Bazel will pick up new *.h glob matches.