Support for aarch64 cpu

Co-authored by: Ryan Johnson <[email protected]>

Author: gabrielrussoc

toolchain/BUILD.tpl

@@ -39,20 +39,27 @@ filegroup(
 cc_toolchain_suite(
     name = "toolchain",
     toolchains = {
-        "k8|clang": ":cc-clang-linux",
+        "k8|clang": ":cc-clang-k8-linux",
+        "aarch64|clang": ":cc-clang-aarch64-linux",
         "darwin|clang": ":cc-clang-darwin",
-        "k8": ":cc-clang-linux",
+        "k8": ":cc-clang-k8-linux",
+        "aarch64": ":cc-clang-aarch64-linux",
         "darwin": ":cc-clang-darwin",
     },
 )
 
 load(":cc_toolchain_config.bzl", "cc_toolchain_config")
 
 cc_toolchain_config(
-    name = "local_linux",
+    name = "local_linux_k8",
     cpu = "k8",
 )
 
+cc_toolchain_config(
+    name = "local_linux_aarch64",
+    cpu = "aarch64",
+)
+
 cc_toolchain_config(
     name = "local_darwin",
     cpu = "darwin",
@@ -73,7 +80,7 @@ toolchain(
 )
 
 toolchain(
-    name = "cc-toolchain-linux",
+    name = "cc-toolchain-k8-linux",
     exec_compatible_with = [
         "@platforms//cpu:x86_64",
         "@platforms//os:linux",
@@ -82,14 +89,29 @@ toolchain(
         "@platforms//cpu:x86_64",
         "@platforms//os:linux",
     ],
-    toolchain = ":cc-clang-linux",
+    toolchain = ":cc-clang-k8-linux",
+    toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",
+)
+
+toolchain(
+    name = "cc-toolchain-aarch64-linux",
+    exec_compatible_with = [
+        "@platforms//cpu:aarch64",
+        "@platforms//os:linux",
+    ],
+    target_compatible_with = [
+        "@platforms//cpu:aarch64",
+        "@platforms//os:linux",
+    ],
+    toolchain = ":cc-clang-aarch64-linux",
     toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",
 )
 
 load("@%{parent_repo_name}//toolchain:rules.bzl", "conditional_cc_toolchain")
 
-conditional_cc_toolchain("cc-clang-linux", False, %{absolute_paths})
-conditional_cc_toolchain("cc-clang-darwin", True, %{absolute_paths})
+conditional_cc_toolchain("cc-clang-k8-linux", "local_linux_k8", False, %{absolute_paths})
+conditional_cc_toolchain("cc-clang-aarch64-linux", "local_linux_aarch64", False, %{absolute_paths})
+conditional_cc_toolchain("cc-clang-darwin", "local_darwin", True, %{absolute_paths})
 
 ## LLVM toolchain files
 # Needed when not using absolute paths.

toolchain/cc_toolchain_config.bzl.tpl

@@ -34,46 +34,59 @@ def _impl(ctx):
     if (ctx.attr.cpu == "darwin"):
         toolchain_identifier = "clang-darwin"
     elif (ctx.attr.cpu == "k8"):
-        toolchain_identifier = "clang-linux"
+        toolchain_identifier = "clang-k8-linux"
+    elif (ctx.attr.cpu == "aarch64"):
+        toolchain_identifier = "clang-aarch64-linux"
     else:
         fail("Unreachable")
 
     if (ctx.attr.cpu == "k8"):
         host_system_name = "x86_64"
+    elif (ctx.attr.cpu == "aarch64"):
+        host_system_name = "aarch64"
     elif (ctx.attr.cpu == "darwin"):
         host_system_name = "x86_64-apple-macosx"
     else:
         fail("Unreachable")
 
-    if (ctx.attr.cpu == "darwin"):
-        target_system_name = "x86_64-apple-macosx"
-    elif (ctx.attr.cpu == "k8"):
+    if (ctx.attr.cpu == "k8"):
         target_system_name = "x86_64-unknown-linux-gnu"
+    elif (ctx.attr.cpu == "aarch64"):
+        target_system_name = "aarch64-unknown-linux-gnu"
+    elif (ctx.attr.cpu == "darwin"):
+        target_system_name = "x86_64-apple-macosx"
     else:
         fail("Unreachable")
 
     if (ctx.attr.cpu == "darwin"):
         target_cpu = "darwin"
     elif (ctx.attr.cpu == "k8"):
         target_cpu = "k8"
+    elif (ctx.attr.cpu == "aarch64"):
+        target_cpu = "aarch64"
     else:
         fail("Unreachable")
 
     if (ctx.attr.cpu == "k8"):
         target_libc = "glibc_unknown"
+    elif (ctx.attr.cpu == "aarch64"):
+        target_libc = "glibc_unknown"
     elif (ctx.attr.cpu == "darwin"):
         target_libc = "macosx"
     else:
         fail("Unreachable")
 
     if (ctx.attr.cpu == "darwin" or
+        ctx.attr.cpu == "aarch64" or
         ctx.attr.cpu == "k8"):
         compiler = "clang"
     else:
         fail("Unreachable")
 
     if (ctx.attr.cpu == "k8"):
         abi_version = "clang"
+    elif (ctx.attr.cpu == "aarch64"):
+        abi_version = "clang"
     elif (ctx.attr.cpu == "darwin"):
         abi_version = "darwin_x86_64"
     else:
@@ -83,12 +96,15 @@ def _impl(ctx):
         abi_libc_version = "darwin_x86_64"
     elif (ctx.attr.cpu == "k8"):
         abi_libc_version = "glibc_unknown"
+    elif (ctx.attr.cpu == "aarch64"):
+        abi_libc_version = "glibc_unknown"
     else:
         fail("Unreachable")
 
     cc_target_os = None
 
     if (ctx.attr.cpu == "darwin" or
+        ctx.attr.cpu == "aarch64" or
         ctx.attr.cpu == "k8"):
         builtin_sysroot = "%{sysroot_path}"
     else:
@@ -144,7 +160,7 @@ def _impl(ctx):
 
     action_configs = []
 
-    if ctx.attr.cpu == "k8":
+    if ctx.attr.cpu in ("k8", "aarch64"):
         linker_flags = [
             # Use the lld linker.
             "-fuse-ld=lld",
@@ -228,7 +244,7 @@ def _impl(ctx):
                 flag_groups = [flag_group(flags = ["-Wl,--gc-sections"])],
                 with_features = [with_feature_set(features = ["opt"])],
             ),
-        ] if ctx.attr.cpu == "k8" else []),
+        ] if ctx.attr.cpu in ("k8", "aarch64") else []),
     )
 
     default_compile_flags_feature = feature(
@@ -503,14 +519,20 @@ def _impl(ctx):
         "%{toolchain_path_prefix}lib/clang/%{llvm_version}/include",
         "%{toolchain_path_prefix}lib64/clang/%{llvm_version}/include",
     ]
-    if (ctx.attr.cpu == "k8"):
+    if (ctx.attr.cpu in ["k8", "aarch64"]):
         cxx_builtin_include_directories += [
             "%{sysroot_prefix}/include",
             "%{sysroot_prefix}/usr/include",
             "%{sysroot_prefix}/usr/local/include",
-        ] + [
+        ]
+    if ctx.attr.cpu == "k8":
+        cxx_builtin_include_directories += [
             %{k8_additional_cxx_builtin_include_directories}
         ]
+    elif ctx.attr.cpu == "aarch64":
+        cxx_builtin_include_directories += [
+            %{aarch64_additional_cxx_builtin_include_directories}
+        ]
     elif (ctx.attr.cpu == "darwin"):
         cxx_builtin_include_directories += [
             "%{sysroot_prefix}/usr/include",
@@ -531,12 +553,12 @@ def _impl(ctx):
                 value = "-Wframe-larger-than=100000000 -Wno-vla",
             ),
         ]
-    elif (ctx.attr.cpu == "k8"):
+    elif (ctx.attr.cpu in ("k8", "aarch64")):
         make_variables = []
     else:
         fail("Unreachable")
 
-    if (ctx.attr.cpu == "k8"):
+    if (ctx.attr.cpu in ("k8", "aarch64")):
         tool_paths = [
             tool_path(
                 name = "ld",
@@ -647,6 +669,7 @@ cc_toolchain_config = rule(
             values = [
                 "darwin",
                 "k8",
+                "aarch64",
             ],
         ),
     },

toolchain/internal/configure.bzl

@@ -76,6 +76,7 @@ def llvm_register_toolchains():
         "%{absolute_paths}": "True" if rctx.attr.absolute_paths else "False",
         "%{makevars_ld_flags}": _makevars_ld_flags(rctx),
         "%{k8_additional_cxx_builtin_include_directories}": _include_dirs_str(rctx, "k8"),
+        "%{aarch64_additional_cxx_builtin_include_directories}": _include_dirs_str(rctx, "aarch64"),
         "%{darwin_additional_cxx_builtin_include_directories}": _include_dirs_str(rctx, "darwin"),
     }
 
@@ -120,12 +121,9 @@ def llvm_register_toolchains():
     if not _download_llvm(rctx, shortos):
         _download_llvm_preconfigured(rctx)
 
-def conditional_cc_toolchain(name, darwin, absolute_paths = False):
+def conditional_cc_toolchain(name, toolchain_config, darwin, absolute_paths = False):
     # Toolchain macro for BUILD file to use conditional logic.
 
-    toolchain_config = "local_darwin" if darwin else "local_linux"
-    toolchain_identifier = "clang-darwin" if darwin else "clang-linux"
-
     if absolute_paths:
         _cc_toolchain(
             name = name,
@@ -151,7 +149,7 @@ def conditional_cc_toolchain(name, darwin, absolute_paths = False):
             ar_files = name + "-archiver-files",
             as_files = name + "-assembler-files",
             compiler_files = name + "-compiler-files",
-            dwp_files = ":empty",
+            dwp_files = ":dwp",
             linker_files = name + "-linker-files",
             objcopy_files = ":objcopy",
             strip_files = ":empty",

toolchain/internal/llvm_distributions.bzl

@@ -256,12 +256,26 @@ def download_llvm_preconfigured(rctx):
         auth = _get_auth(rctx, urls),
     )
 
+def _arch(rctx):
+    exec_result = rctx.execute([
+        _python(rctx),
+        "-c",
+        "import platform; print(platform.machine())",
+    ])
+    if exec_result.return_code:
+        fail("Failed to detect machine architecture: \n%s\n%s" % (exec_result.stdout, exec_result.stderr))
+    return exec_result.stdout.strip()
+
 # Download LLVM from the user-provided URLs and return True. If URLs were not provided, return
 # False.
 def download_llvm(rctx, shortos):
-    urls = rctx.attr.urls.get(shortos, default = [])
-    sha256 = rctx.attr.sha256.get(shortos, default = "")
-    prefix = rctx.attr.strip_prefix.get(shortos, default = "")
+    if shortos == "linux":
+        key = "linux-{}".format(_arch(rctx))
+    else:
+        key = shortos
+    urls = rctx.attr.urls.get(key, default = [])
+    sha256 = rctx.attr.sha256.get(key, default = "")
+    prefix = rctx.attr.strip_prefix.get(key, default = "")
 
     if not urls:
         return False

toolchain/rules.bzl

@@ -45,8 +45,8 @@ llvm_toolchain = repository_rule(
         "cxx_builtin_include_directories": attr.string_list_dict(
             mandatory = False,
             doc = ("Additional builtin include directories to be added to the default system " +
-                   "directories, keyed by the CPU type (e.g. k8 or darwin). See documentation " +
-                   "for bazel's create_cc_toolchain_config_info."),
+                   "directories, keyed by the CPU type (e.g. k8, aarch64 or darwin). See " +
+                   "documentation for bazel's create_cc_toolchain_config_info."),
         ),
         "llvm_mirror": attr.string(
             doc = "Mirror base for LLVM binaries if using the pre-configured URLs.",
@@ -63,7 +63,8 @@ llvm_toolchain = repository_rule(
         # Following attributes are needed only when using a non-standard URL scheme.
         "urls": attr.string_list_dict(
             mandatory = False,
-            doc = "URLs for each OS type (linux and darwin) if not using the pre-configured URLs.",
+            doc = ("URLs for each OS type and arch pairs (linux-x86_64, linux-aarch64 and darwin) " +
+                   "if not using the pre-configured URLs."),
         ),
         "sha256": attr.string_dict(
             mandatory = False,

toolchain/toolchains.bzl.tpl

@@ -14,6 +14,7 @@
 
 def llvm_register_toolchains():
     native.register_toolchains(
-        "@%{repo_name}//:cc-toolchain-linux",
+        "@%{repo_name}//:cc-toolchain-k8-linux",
+        "@%{repo_name}//:cc-toolchain-aarch64-linux",
         "@%{repo_name}//:cc-toolchain-darwin",
     )