[PATCH] D109839: Add support for targeting macOS arm64 with bazel

[Geoffrey Martin-Noble via Phabricator via llvm-commits]

GMNGeoffrey added inline comments.


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Comment at: utils/bazel/llvm-project-overlay/llvm/BUILD.bazel:21
+# Support for targeting macOS arm64 architecture with `bazel<4.2`. This
+# implementation is lifted from `src/conditions/BUILD` in the bazel source.
+config_setting(
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We already use `@bazel_tools//src/conditions:foo` in config.bzl. Looking at the history of src/conditions/BUILD, there's some bug in Bazel that means that cross-compiling from darwinn x86 to darwinn arm is broken and this is worked around in src/conditions by adding a `--darwin_arm64` flag (https://github.com/bazelbuild/bazel/issues/12655 and https://github.com/bazelbuild/bazel/commit/52457b18bd), but only after Bazel 4.0 (the version we're currently on). Is that cross-compiling something you actually need? If not, I'd prefer we use the src/conditions constraints for now (at least until such a time as we decide to define all our own config settings)


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Comment at: utils/bazel/llvm-project-overlay/llvm/config.bzl:78-79
     "@bazel_tools//src/conditions:windows": native_arch_defines("X86", "x86_64-pc-win32"),
-    "@bazel_tools//src/conditions:darwin": native_arch_defines("X86", "x86_64-unknown-darwin"),
+    "//llvm:macos_arm64": native_arch_defines("AArch64", "arm64-apple-darwin"),
+    "//llvm:macos_x86_64": native_arch_defines("X86", "x86_64-apple-darwin"),
     "@bazel_tools//src/conditions:linux_aarch64": native_arch_defines("AArch64", "aarch64-unknown-linux-gnu"),
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