Build with bazel on linux-arm64 (#16)

.bazelrc

@@ -9,5 +9,10 @@ build --action_env=BAZEL_DO_NOT_DETECT_CPP_TOOLCHAIN=1
 # https://github.com/bazelbuild/bazel/issues/7260.
 build --incompatible_enable_cc_toolchain_resolution
 
+# Add aliases for compiler version build settings.
+build --flag_alias=aarch64_linux_gnu_gcc_version=//:aarch64_linux_gnu_gcc_version
+build --flag_alias=clang_version=//:clang_version
+build --flag_alias=gcc_version=//:gcc_version
+
 # Any personal configuration should go in .user.bazelrc.
 try-import %workspace%/.user.bazelrc

BUILD.bazel

@@ -1,9 +1,11 @@
+load("//bazel:common_settings.bzl", "string_flag")
+
 #
 # OS-CPU CONFIG SETTINGS
 #
 
 config_setting(
-    name = "linux-arm64",
+    name = "linux_arm64",
     constraint_values = [
         "@platforms//os:linux",
         "@platforms//cpu:arm64",
@@ -11,7 +13,7 @@ config_setting(
 )
 
 config_setting(
-    name = "linux-x86_64",
+    name = "linux_x86_64",
     constraint_values = [
         "@platforms//os:linux",
         "@platforms//cpu:x86_64",
@@ -19,7 +21,7 @@ config_setting(
 )
 
 config_setting(
-    name = "macos-arm64",
+    name = "macos_arm64",
     constraint_values = [
         "@platforms//os:macos",
         "@platforms//cpu:arm64",
@@ -27,7 +29,7 @@ config_setting(
 )
 
 config_setting(
-    name = "macos-x86_64",
+    name = "macos_x86_64",
     constraint_values = [
         "@platforms//os:macos",
         "@platforms//cpu:x86_64",
@@ -35,7 +37,7 @@ config_setting(
 )
 
 config_setting(
-    name = "openbsd-x86_64",
+    name = "openbsd_x86_64",
     constraint_values = [
         "@platforms//os:openbsd",
         "@platforms//cpu:x86_64",
@@ -43,7 +45,7 @@ config_setting(
 )
 
 config_setting(
-    name = "windows-x86_64",
+    name = "windows_x86_64",
     constraint_values = [
         "@platforms//os:windows",
         "@platforms//cpu:x86_64",
@@ -51,27 +53,90 @@ config_setting(
 )
 
 #
-# COMPILER CONSTRAINT SETTINGS
+# COMPILERS
 #
 
 constraint_setting(name = "compiler")
 
+# Cross compiler from x86_64 to arm64.
+constraint_value(
+    name = "aarch64_linux_gnu_gcc",
+    constraint_setting = ":compiler",
+    visibility = ["//visibility:public"],
+)
+
+# Compiler for x86_64.
 constraint_value(
     name = "clang",
     constraint_setting = ":compiler",
     visibility = ["//visibility:public"],
 )
 
+# Compiler for x86_64.
 constraint_value(
     name = "gcc",
     constraint_setting = ":compiler",
     visibility = ["//visibility:public"],
 )
 
+# Version flag for aarch64-linux-gnu-gcc.
+string_flag(
+    name = "aarch64_linux_gnu_gcc_version",
+    build_setting_default = "12.2.0",
+    visibility = ["//visibility:public"],
+)
+
+# Version flag for clang.
+string_flag(
+    name = "clang_version",
+    build_setting_default = "14.0.6",
+    visibility = ["//visibility:public"],
+)
+
+# Version flag for gcc.
+string_flag(
+    name = "gcc_version",
+    build_setting_default = "12.2.0",
+    visibility = ["//visibility:public"],
+)
+
 #
 # PLATFORMS
 #
 
+# A platform takes one of two formats: `<compiler>-<os>-<cpu>` or `<os>-<cpu>`
+# if the compiler is unspecified.
+
+# Linux arm64 platform with unspecified compiler.
+platform(
+    name = "linux-arm64",
+    constraint_values = [
+        "@platforms//os:linux",
+        "@platforms//cpu:arm64",
+    ],
+)
+
+# Linux x86_64 platform with unspecified compiler.
+platform(
+    name = "linux-x86_64",
+    constraint_values = [
+        "@platforms//os:linux",
+        "@platforms//cpu:x86_64",
+    ],
+)
+
+# Linux x86_64 platform with aarch64-linux-gnu-gcc.
+platform(
+    name = "aarch64_linux_gnu_gcc-linux-x86_64",
+    constraint_values = [
+        ":aarch64_linux_gnu_gcc",
+        "@platforms//os:linux",
+        "@platforms//cpu:x86_64",
+    ],
+    visibility = ["//visibility:public"],
+)
+
+# Linux x86_64 platform with clang.
 platform(
     name = "clang-linux-x86_64",
     constraint_values = [
@@ -82,6 +147,7 @@ platform(
     visibility = ["//visibility:public"],
 )
 
+# Linux x86_64 platform with gcc.
 platform(
     name = "gcc-linux-x86_64",
     constraint_values = [

README.md

@@ -31,31 +31,63 @@ defined in its own package:
 
 ## Build
 
-We use [`bazel`][bazel] to build Urbit's runtime. We support the following
-platforms:
+We use [`bazel`][bazel] to build Urbit's runtime, which is packaged as a single
+binary, `urbit`. We support the following `(host, target)` pairs, where the host
+platform is where [`bazel`][bazel] runs and the target platform is where `urbit`
+will run:
 
-- `darwin-arm64` (macOS running Apple Silicon)
-- `darwin-x86_64` (macOS running Intel silicon)
-- `linux-arm64`
-- `linux-x86_64`
-- `openbsd-x86_64`
-- `mingw-x86_64`
+--------------------------------------------------------------------------------
+ Host Platform                        | Target Platform | Required Toolchain
+--------------------------------------------------------------------------------
+ `aarch64_linux_gnu_gcc-linux-x86_64` | `linux-arm64`   | `aarch64-linux_gnu_gcc`
+ `gcc-linux-x86_64`                   | `linux-x86_64`  | `gcc`
+ `clang-linux-x86_64`                 | `linux-x86_64`  | `clang`
 
-To build the `urbit` binary, the primary artifact of this repository, ensure
-that you're on a supported platform and that you have an up-to-date version of
-[`bazel`][bazel], and then run:
+Once you've identified your `(host, target)` pair, determine the version of the
+pair's required toolchain and ensure you have an up-to-date version of
+[`bazel`][bazel]. Then, run:
 
 ```console
-$ bazel build :urbit
+$ bazel build --<toolchain>_version="<toolchain_version>" \
+              --host_platform=//:<host_platform>          \
+              --platforms=//:<target_platform> :urbit
 ```
 
-The build will take a while since `bazel` has to download and build from source
-all of `urbit`'s third-party dependencies.
+For example, to build a `linux-x86_64` `urbit` binary on a `linux-x86_64`
+machine using version `14.0.6` of the `clang` toolchain, run:
+
+```console
+$ bazel build --clang_version="14.0.6"            \
+              --host_platform=//:gcc-linux-x86_64 \
+              --platforms=//:linux-x86_64
+```
+
+And to build a `linux-arm64` `urbit` binary on a `linux-x86_64` machine using
+version `12.2.0` of the `aarch64-linux-gnu-gcc` toolchain (which you'll have to
+install), run:
+
+```console
+$ bazel build --aarch64_linux_gnu_gcc_version="12.2.0"              \
+              --host_platform=//:aarch64_linux_gnu_gcc-linux-x86_64 \
+              --platforms=//:linux-arm64
+```
+
+Specifying `--<toolchain>_version`, `--host_platform`, and `--platforms` for
+each build is tedious and can be avoided by writing to `.user.bazelrc`:
+
+```console
+$ echo 'build --aarch64_linux_gnu_gcc_version="12.2.0"' >> .user.bazelrc
+$ echo 'build --clang_version="14.0.6"'                 >> .user.bazelrc
+$ echo 'build --gcc_version="12.2.0"'                   >> .user.bazelrc
+$ echo 'build --host_platform=//:<host_platform>'       >> .user.bazelrc
+$ echo 'build --platforms=//:<target_platform>'         >> .user.bazelrc
+$ bazel build :urbit
+```
 
 To run the just-built `urbit` binary, run:
 
 ```console
-$ bazel-bin/pkg/vere/urbit ...
+$ bazel-bin/pkg/vere/urbit <snip>
 ```
 
 Or, to save yourself a few keystrokes, create a symlink to the `urbit` binary in
@@ -63,9 +95,13 @@ the root of the repository:
 
 ```console
 $ ln -s bazel-bin/pkg/vere/urbit urbit
-$ ./urbit ...
+$ ./urbit <snip>
 ```
 
+The remaining commands in this section assume that `.user.bazlerc` specifies
+`--host_platform` and `--platforms`. If not, `--host_platform` and `--platforms`
+must be provided at the command line as in the build commands above.
+
 To run all runtime tests, run:
 
 ```console

WORKSPACE.bazel

@@ -73,13 +73,20 @@ versioned_http_archive(
 
 # Use the toolchains we've configured.
 register_toolchains(
+    "//bazel/toolchain:aarch64_linux_gnu_gcc-linux-x86_64-toolchain",
     "//bazel/toolchain:clang-linux-x86_64-toolchain",
     "//bazel/toolchain:gcc-linux-x86_64-toolchain",
 )
 
 load("@rules_foreign_cc//foreign_cc:repositories.bzl", "rules_foreign_cc_dependencies")
 
-rules_foreign_cc_dependencies()
+# See
+# https://bazelbuild.github.io/rules_foreign_cc/0.9.0/flatten.html#rules_foreign_cc_dependencies.
+rules_foreign_cc_dependencies(
+    register_built_tools = False,
+    register_default_tools = False,
+    register_preinstalled_tools = True,
+)
 
 #
 # THIRD PARTY DEPENDENCIES
@@ -141,6 +148,8 @@ versioned_http_archive(
 versioned_http_archive(
     name = "h2o",
     build_file = "//bazel/third_party/h2o:h2o.BUILD",
+    patch_args = ["-p1"],
+    patches = ["//bazel/third_party/h2o:{version}.patch"],
     sha256 = "f8cbc1b530d85ff098f6efc2c3fdbc5e29baffb30614caac59d5c710f7bda201",
     strip_prefix = "h2o-{version}",
     url = "https://github.com/h2o/h2o/archive/refs/tags/v{version}.tar.gz",
@@ -244,6 +253,15 @@ versioned_http_archive(
     version = "5c06db33fc1e2130f67c045327b0ec949032df1d",
 )
 
+versioned_http_archive(
+    name = "sse2neon",
+    build_file = "//bazel/third_party/sse2neon:sse2neon.BUILD",
+    sha256 = "4001e2dfb14fcf3831211581ed83bcc83cf6a3a69f638dcbaa899044a351bb2a",
+    strip_prefix = "sse2neon-{version}",
+    url = "https://github.com/DLTcollab/sse2neon/archive/refs/tags/v{version}.tar.gz",
+    version = "1.5.1",
+)
+
 versioned_http_archive(
     name = "uv",
     build_file = "//bazel/third_party/uv:uv.BUILD",

bazel/common_settings.bzl

@@ -0,0 +1,12 @@
+# For more, see https://bazel.build/extending/config and
+# https://github.com/bazelbuild/bazel-skylib/blob/main/rules/common_settings.bzl.
+load("@bazel_skylib//rules:common_settings.bzl", "BuildSettingInfo")
+
+def _impl(ctx):
+    return BuildSettingInfo(value = ctx.build_setting_value)
+
+string_flag = rule(
+    implementation = _impl,
+    build_setting = config.string(flag = True),
+    doc = "A string-typed build setting that can be set on the command line",
+)

bazel/third_party/curl/curl.BUILD

@@ -47,12 +47,15 @@ configure_make(
         "--without-librtmp",
         "--without-nghttp2",
         "--without-ngtcp2",
-        "--without-ssl",
         "--without-zlib",
         "--without-zstd",
-    ],
+    ] + select({
+        # Native compilation on linux-arm64 isn't supported.
+        "@//:linux_arm64": ["--host=aarch64-linux-gnu"],
+        "//conditions:default": [],
+    }),
     env = {
-        "URBIT_RUNTIME_OPENSSL": "$(GENDIR)/external/openssl/openssl",
+        "URBIT_RUNTIME_OPENSSL": "$$PWD/$(GENDIR)/external/openssl/openssl",
     },
     lib_source = ":all",
     out_static_libs = ["libcurl.a"],

bazel/third_party/gmp/gmp.BUILD

@@ -9,7 +9,13 @@ filegroup(
 configure_make(
     name = "gmp",
     args = ["--jobs=`nproc`"],
-    configure_options = ["--disable-shared"],
+    configure_options = [
+        "--disable-shared",
+    ] + select({
+        # Native compilation on linux-arm64 isn't supported.
+        "@//:linux_arm64": ["--host=aarch64-linux-gnu"],
+        "//conditions:default": [],
+    }),
     lib_source = ":all",
     out_static_libs = ["libgmp.a"],
     visibility = ["//visibility:public"],

bazel/third_party/h2o/2.2.6.patch

@@ -0,0 +1,47 @@
+diff --git a/deps/klib/ksw.c b/deps/klib/ksw.c
+index 742fec90b..9a11a21bd 100644
+--- a/deps/klib/ksw.c
++++ b/deps/klib/ksw.c
+@@ -25,7 +25,11 @@
+
+ #include <stdlib.h>
+ #include <stdint.h>
++#if defined(URBIT_RUNTIME_ARCH_ARM64)
++#include "sse2neon.h"
++#else
+ #include <emmintrin.h>
++#endif
+ #include "ksw.h"
+
+ #ifdef __GNUC__
+diff --git a/deps/klib/test/kbit_test.c b/deps/klib/test/kbit_test.c
+index 3ae3bd309..7db05a186 100644
+--- a/deps/klib/test/kbit_test.c
++++ b/deps/klib/test/kbit_test.c
+@@ -1,7 +1,11 @@
+ #include <stdlib.h>
+ #include <stdio.h>
+ #include <time.h>
++#if defined(URBIT_RUNTIME_ARCH_ARM64)
++#include "sse2neon.h"
++#else
+ #include <emmintrin.h>
++#endif
+ #include "kbit.h"
+
+ // from bowtie-0.9.8.1
+diff --git a/deps/picohttpparser/picohttpparser.c b/deps/picohttpparser/picohttpparser.c
+index a707070d1..714850f64 100644
+--- a/deps/picohttpparser/picohttpparser.c
++++ b/deps/picohttpparser/picohttpparser.c
+@@ -28,7 +28,9 @@
+ #include <stddef.h>
+ #include <string.h>
+ #ifdef __SSE4_2__
+-#ifdef _MSC_VER
++#if defined(URBIT_RUNTIME_ARCH_ARM64)
++#include "sse2neon.h"
++#elif defined(_MSC_VER)
+ #include <nmmintrin.h>
+ #else
+ #include <x86intrin.h>

bazel/third_party/h2o/h2o.BUILD

@@ -42,8 +42,18 @@ cc_library(
     hdrs = glob(["deps/klib/*.h"]),
     includes = ["deps/klib"],
     linkstatic = True,
+    local_defines = select({
+        "@platforms//cpu:arm64": ["URBIT_RUNTIME_ARCH_ARM64"],
+        "//conditions:default": [],
+    }),
     visibility = ["//visibility:private"],
-    deps = ["@curl"],
+    deps = [
+        "@curl",
+        "@zlib",
+    ] + select({
+        "@platforms//cpu:arm64": ["@sse2neon"],
+        "//conditions:default": [],
+    }),
 )
 
 # See `deps/libgkc` in the `h2o` repo.
@@ -132,9 +142,7 @@ cc_library(
 # See `deps/yoml` in the `h2o` repo.
 cc_library(
     name = "yoml",
-    hdrs = glob(
-        ["deps/yoml/*.h"],
-    ),
+    hdrs = glob(["deps/yoml/*.h"]),
     includes = ["deps/yoml"],
     linkstatic = True,
     visibility = ["//visibility:private"],
@@ -305,9 +313,8 @@ cc_library(
     hdrs = ["include/h2o.h"] + glob(
         [
             "include/h2o/*.h",
+            "include/h2o/socket/*.h",
         ],
-    ) + glob(
-        ["include/h2o/socket/*.h"],
     ),
     copts = [
         "-std=c99",

bazel/third_party/openssl/openssl.BUILD

@@ -11,12 +11,22 @@ configure_make(
     args = ["--jobs=`nproc`"],
     configure_command = select({
         "@platforms//os:windows": "Configure",
+        "@//:linux_arm64": "Configure",
         "//conditions:default": "config",
     }),
     configure_options = [
         "no-shared",
     ] + select({
         "@platforms//os:windows": ["mingw64"],
+        "@//:linux_arm64": [
+            "linux-aarch64",
+            # Native compilation on linux-arm64 isn't supported. The prefix is
+            # empty because the configure script detects an absolute path to the
+            # aarch64-linux-gnu-gcc instead of just the binary name. This is
+            # presumably because of the Bazel toolchain configuration but is not
+            # an issue.
+            "--cross-compile-prefix=",
+        ],
         "//conditions:default": [],
     }),
     configure_prefix = select({

bazel/third_party/secp256k1/secp256k1.BUILD

@@ -15,7 +15,11 @@ configure_make(
         "--enable-module-recovery",
         "--enable-module-schnorrsig",
         "--enable-static",
-    ],
+    ] + select({
+        # Native compilation on linux-arm64 isn't supported.
+        "@//:linux_arm64": ["--host=aarch64-linux-gnu"],
+        "//conditions:default": [],
+    }),
     lib_source = ":all",
     out_static_libs = ["libsecp256k1.a"],
     visibility = ["//visibility:public"],

bazel/third_party/sigsegv/sigsegv.BUILD

@@ -16,6 +16,10 @@ configure_make(
         # slowdowns.
         "@platforms//os:linux": ["--disable-stackvma"],
         "//conditions:default": [],
+    }) + select({
+        # Native compilation on linux-arm64 isn't supported.
+        "@//:linux_arm64": ["--host=aarch64-linux-gnu"],
+        "//conditions:default": [],
     }),
     lib_source = ":all",
     out_static_libs = ["libsigsegv.a"],

bazel/third_party/softfloat/softfloat.BUILD

@@ -7,6 +7,280 @@ load("@rules_foreign_cc//foreign_cc:defs.bzl", "make")
 # repo, was useful in deriving this build file:
 #   http://www.jhauser.us/arithmetic/SoftFloat-3/doc/SoftFloat-source.html
 
+cc_library(
+    name = "softfloat_linux_arm64",
+    srcs = [
+        # See `OBJS_PRIMITIVES` in `build/Linux-ARM-VFPv2-GCC/Makefile` in the
+        # `softfloat` repo.
+        "source/s_compare96M.c",
+        "source/s_compare128M.c",
+        "source/s_shortShiftLeft64To96M.c",
+        "source/s_shortShiftLeftM.c",
+        "source/s_shiftLeftM.c",
+        "source/s_shortShiftRightM.c",
+        "source/s_shortShiftRightJam64.c",
+        "source/s_shortShiftRightJamM.c",
+        "source/s_shiftRightJam32.c",
+        "source/s_shiftRightJam64.c",
+        "source/s_shiftRightJamM.c",
+        "source/s_shiftRightM.c",
+        "source/s_countLeadingZeros8.c",
+        "source/s_countLeadingZeros16.c",
+        "source/s_countLeadingZeros32.c",
+        "source/s_countLeadingZeros64.c",
+        "source/s_addM.c",
+        "source/s_addCarryM.c",
+        "source/s_addComplCarryM.c",
+        "source/s_negXM.c",
+        "source/s_sub1XM.c",
+        "source/s_subM.c",
+        "source/s_mul64To128M.c",
+        "source/s_mul128MTo256M.c",
+        "source/s_approxRecip_1Ks.c",
+        "source/s_approxRecip32_1.c",
+        "source/s_approxRecipSqrt_1Ks.c",
+        "source/s_approxRecipSqrt32_1.c",
+        "source/s_remStepMBy32.c",
+        # See `OBJS_SPECIALIZE` in `build/Linux-ARM-VFPv2-GCC/Makefile` in the
+        # `softfloat` repo.
+        "source/ARM-VFPv2/softfloat_raiseFlags.c",
+        "source/ARM-VFPv2/s_f16UIToCommonNaN.c",
+        "source/ARM-VFPv2/s_commonNaNToF16UI.c",
+        "source/ARM-VFPv2/s_propagateNaNF16UI.c",
+        "source/ARM-VFPv2/s_f32UIToCommonNaN.c",
+        "source/ARM-VFPv2/s_commonNaNToF32UI.c",
+        "source/ARM-VFPv2/s_propagateNaNF32UI.c",
+        "source/ARM-VFPv2/s_f64UIToCommonNaN.c",
+        "source/ARM-VFPv2/s_commonNaNToF64UI.c",
+        "source/ARM-VFPv2/s_propagateNaNF64UI.c",
+        "source/ARM-VFPv2/extF80M_isSignalingNaN.c",
+        "source/ARM-VFPv2/s_extF80MToCommonNaN.c",
+        "source/ARM-VFPv2/s_commonNaNToExtF80M.c",
+        "source/ARM-VFPv2/s_propagateNaNExtF80M.c",
+        "source/ARM-VFPv2/f128M_isSignalingNaN.c",
+        "source/ARM-VFPv2/s_f128MToCommonNaN.c",
+        "source/ARM-VFPv2/s_commonNaNToF128M.c",
+        "source/ARM-VFPv2/s_propagateNaNF128M.c",
+        # See `OBJS_OTHERS` in `build/Linux-ARM-VFPv2-GCC/Makefile` in the
+        # `softfloat` repo.
+        "source/s_roundToUI32.c",
+        "source/s_roundMToUI64.c",
+        "source/s_roundToI32.c",
+        "source/s_roundMToI64.c",
+        "source/s_normSubnormalF16Sig.c",
+        "source/s_roundPackToF16.c",
+        "source/s_normRoundPackToF16.c",
+        "source/s_addMagsF16.c",
+        "source/s_subMagsF16.c",
+        "source/s_mulAddF16.c",
+        "source/s_normSubnormalF32Sig.c",
+        "source/s_roundPackToF32.c",
+        "source/s_normRoundPackToF32.c",
+        "source/s_addMagsF32.c",
+        "source/s_subMagsF32.c",
+        "source/s_mulAddF32.c",
+        "source/s_normSubnormalF64Sig.c",
+        "source/s_roundPackToF64.c",
+        "source/s_normRoundPackToF64.c",
+        "source/s_addMagsF64.c",
+        "source/s_subMagsF64.c",
+        "source/s_mulAddF64.c",
+        "source/s_tryPropagateNaNExtF80M.c",
+        "source/s_invalidExtF80M.c",
+        "source/s_normExtF80SigM.c",
+        "source/s_roundPackMToExtF80M.c",
+        "source/s_normRoundPackMToExtF80M.c",
+        "source/s_addExtF80M.c",
+        "source/s_compareNonnormExtF80M.c",
+        "source/s_isNaNF128M.c",
+        "source/s_tryPropagateNaNF128M.c",
+        "source/s_invalidF128M.c",
+        "source/s_shiftNormSigF128M.c",
+        "source/s_roundPackMToF128M.c",
+        "source/s_normRoundPackMToF128M.c",
+        "source/s_addF128M.c",
+        "source/s_mulAddF128M.c",
+        "source/softfloat_state.c",
+        "source/ui32_to_f16.c",
+        "source/ui32_to_f32.c",
+        "source/ui32_to_f64.c",
+        "source/ui32_to_extF80M.c",
+        "source/ui32_to_f128M.c",
+        "source/ui64_to_f16.c",
+        "source/ui64_to_f32.c",
+        "source/ui64_to_f64.c",
+        "source/ui64_to_extF80M.c",
+        "source/ui64_to_f128M.c",
+        "source/i32_to_f16.c",
+        "source/i32_to_f32.c",
+        "source/i32_to_f64.c",
+        "source/i32_to_extF80M.c",
+        "source/i32_to_f128M.c",
+        "source/i64_to_f16.c",
+        "source/i64_to_f32.c",
+        "source/i64_to_f64.c",
+        "source/i64_to_extF80M.c",
+        "source/i64_to_f128M.c",
+        "source/f16_to_ui32.c",
+        "source/f16_to_ui64.c",
+        "source/f16_to_i32.c",
+        "source/f16_to_i64.c",
+        "source/f16_to_ui32_r_minMag.c",
+        "source/f16_to_ui64_r_minMag.c",
+        "source/f16_to_i32_r_minMag.c",
+        "source/f16_to_i64_r_minMag.c",
+        "source/f16_to_f32.c",
+        "source/f16_to_f64.c",
+        "source/f16_to_extF80M.c",
+        "source/f16_to_f128M.c",
+        "source/f16_roundToInt.c",
+        "source/f16_add.c",
+        "source/f16_sub.c",
+        "source/f16_mul.c",
+        "source/f16_mulAdd.c",
+        "source/f16_div.c",
+        "source/f16_rem.c",
+        "source/f16_sqrt.c",
+        "source/f16_eq.c",
+        "source/f16_le.c",
+        "source/f16_lt.c",
+        "source/f16_eq_signaling.c",
+        "source/f16_le_quiet.c",
+        "source/f16_lt_quiet.c",
+        "source/f16_isSignalingNaN.c",
+        "source/f32_to_ui32.c",
+        "source/f32_to_ui64.c",
+        "source/f32_to_i32.c",
+        "source/f32_to_i64.c",
+        "source/f32_to_ui32_r_minMag.c",
+        "source/f32_to_ui64_r_minMag.c",
+        "source/f32_to_i32_r_minMag.c",
+        "source/f32_to_i64_r_minMag.c",
+        "source/f32_to_f16.c",
+        "source/f32_to_f64.c",
+        "source/f32_to_extF80M.c",
+        "source/f32_to_f128M.c",
+        "source/f32_roundToInt.c",
+        "source/f32_add.c",
+        "source/f32_sub.c",
+        "source/f32_mul.c",
+        "source/f32_mulAdd.c",
+        "source/f32_div.c",
+        "source/f32_rem.c",
+        "source/f32_sqrt.c",
+        "source/f32_eq.c",
+        "source/f32_le.c",
+        "source/f32_lt.c",
+        "source/f32_eq_signaling.c",
+        "source/f32_le_quiet.c",
+        "source/f32_lt_quiet.c",
+        "source/f32_isSignalingNaN.c",
+        "source/f64_to_ui32.c",
+        "source/f64_to_ui64.c",
+        "source/f64_to_i32.c",
+        "source/f64_to_i64.c",
+        "source/f64_to_ui32_r_minMag.c",
+        "source/f64_to_ui64_r_minMag.c",
+        "source/f64_to_i32_r_minMag.c",
+        "source/f64_to_i64_r_minMag.c",
+        "source/f64_to_f16.c",
+        "source/f64_to_f32.c",
+        "source/f64_to_extF80M.c",
+        "source/f64_to_f128M.c",
+        "source/f64_roundToInt.c",
+        "source/f64_add.c",
+        "source/f64_sub.c",
+        "source/f64_mul.c",
+        "source/f64_mulAdd.c",
+        "source/f64_div.c",
+        "source/f64_rem.c",
+        "source/f64_sqrt.c",
+        "source/f64_eq.c",
+        "source/f64_le.c",
+        "source/f64_lt.c",
+        "source/f64_eq_signaling.c",
+        "source/f64_le_quiet.c",
+        "source/f64_lt_quiet.c",
+        "source/f64_isSignalingNaN.c",
+        "source/extF80M_to_ui32.c",
+        "source/extF80M_to_ui64.c",
+        "source/extF80M_to_i32.c",
+        "source/extF80M_to_i64.c",
+        "source/extF80M_to_ui32_r_minMag.c",
+        "source/extF80M_to_ui64_r_minMag.c",
+        "source/extF80M_to_i32_r_minMag.c",
+        "source/extF80M_to_i64_r_minMag.c",
+        "source/extF80M_to_f16.c",
+        "source/extF80M_to_f32.c",
+        "source/extF80M_to_f64.c",
+        "source/extF80M_to_f128M.c",
+        "source/extF80M_roundToInt.c",
+        "source/extF80M_add.c",
+        "source/extF80M_sub.c",
+        "source/extF80M_mul.c",
+        "source/extF80M_div.c",
+        "source/extF80M_rem.c",
+        "source/extF80M_sqrt.c",
+        "source/extF80M_eq.c",
+        "source/extF80M_le.c",
+        "source/extF80M_lt.c",
+        "source/extF80M_eq_signaling.c",
+        "source/extF80M_le_quiet.c",
+        "source/extF80M_lt_quiet.c",
+        "source/f128M_to_ui32.c",
+        "source/f128M_to_ui64.c",
+        "source/f128M_to_i32.c",
+        "source/f128M_to_i64.c",
+        "source/f128M_to_ui32_r_minMag.c",
+        "source/f128M_to_ui64_r_minMag.c",
+        "source/f128M_to_i32_r_minMag.c",
+        "source/f128M_to_i64_r_minMag.c",
+        "source/f128M_to_f16.c",
+        "source/f128M_to_f32.c",
+        "source/f128M_to_f64.c",
+        "source/f128M_to_extF80M.c",
+        "source/f128M_roundToInt.c",
+        "source/f128M_add.c",
+        "source/f128M_sub.c",
+        "source/f128M_mul.c",
+        "source/f128M_mulAdd.c",
+        "source/f128M_div.c",
+        "source/f128M_rem.c",
+        "source/f128M_sqrt.c",
+        "source/f128M_eq.c",
+        "source/f128M_le.c",
+        "source/f128M_lt.c",
+        "source/f128M_eq_signaling.c",
+        "source/f128M_le_quiet.c",
+        "source/f128M_lt_quiet.c",
+        # See `$(OBJS_ALL)` target in `build/Linux-ARM-VFPv2-GCC/Makefile` in the
+        # `softfloat` repo.
+        "build/Linux-ARM-VFPv2-GCC/platform.h",
+        "source/include/primitiveTypes.h",
+        "source/include/primitives.h",
+        # See `$(OBJS_SPECIALIZE) $(OBJS_OTHERS)` target in
+        # `build/Linux-ARM-VFPv2-GCC/Makefile` in the `softfloat` repo.
+        "source/include/softfloat_types.h",
+        "source/include/internals.h",
+        "source/ARM-VFPv2/specialize.h",
+        # `platform.h` includes `opts-GCC.h`.
+        "source/include/opts-GCC.h",
+    ],
+    hdrs = ["source/include/softfloat.h"],
+    copts = [
+        "-Iexternal/softfloat/build/Linux-ARM-VFPv2-GCC",
+        "-Iexternal/softfloat/source/ARM-VFPv2",
+        "-Werror-implicit-function-declaration",
+        "-O2",
+    ],
+    includes = ["source/include"],
+    local_defines = [
+        "SOFTFLOAT_ROUND_ODD",
+        "INLINE_LEVEL=5",
+    ],
+    visibility = ["//visibility:private"],
+)
+
 cc_library(
     name = "softfloat_linux_x86_64",
     srcs = [
@@ -358,6 +632,7 @@ cc_library(
     name = "softfloat",
     visibility = ["//visibility:public"],
     deps = select({
-        "@//:linux-x86_64": [":softfloat_linux_x86_64"],
+        "@//:linux_arm64": [":softfloat_linux_arm64"],
+        "@//:linux_x86_64": [":softfloat_linux_x86_64"],
     }),
 )

bazel/third_party/sse2neon/sse2neon.BUILD

@@ -0,0 +1,6 @@
+cc_library(
+    name = "sse2neon",
+    hdrs = ["sse2neon.h"],
+    linkstatic = True,
+    visibility = ["//visibility:public"],
+)

bazel/third_party/uv/uv.BUILD

@@ -13,7 +13,11 @@ configure_make(
     configure_in_place = True,
     configure_options = [
         "--disable-shared",
-    ],
+    ] + select({
+        # Native compilation on linux-arm64 isn't supported.
+        "@//:linux_arm64": ["--host=aarch64-linux-gnu"],
+        "//conditions:default": [],
+    }),
     lib_source = ":all",
     out_static_libs = ["libuv.a"],
     targets = ["install"],

bazel/toolchain/BUILD.bazel

@@ -1,3 +1,30 @@
+# ADDING A NEW TOOLCHAIN
+#
+# The general process for adding a new toolchain is as follows:
+#
+# (1) Define a `cc_toolchaing_config()` rule target with a `name` attribute of
+#     the form `<compiler>-<os>-<cpu>-config` and a `toolchain_identifier` of
+#     the form `toolchain-<compiler>-<os>-<cpu>`. The `cc_toolchain_config()`
+#     definition in `//bazel/toolchain:cfg.bzl` lists the mandatory attributes
+#     for the `cc_toolchain_config()` rule. If any of the toolchain's include
+#     paths require a compiler version number, simply replace the version number
+#     with `{compiler_version}`, which is replaced with the value of the label
+#     indicated by the `compiler_version` attribute when the rule is resolved.
+# (2) Define a `cc_toolchain()` rule target with a `name` attribute of the form
+#     `<compiler>-<os>-<cpu>` and a `toolchain_config` attribute that references
+#     the `cc_toolchain_config()` target from (1).
+# (3) Define a `toolchain()` rule target with a `name` attribute of the form
+#     `<compiler>-<os>-<cpu>-toolchain` and specify the platform the toolchain
+#     runs on via the `exec_compatible_with` attribute and the platform the
+#     toolchain targets (i.e. compiles for) via the `target_compatible_with`
+#     attribute. Use the `cc_toolchain()` target from (2) as the value of the
+#     `toolchain` attribute and `:toolchain_type` for the `toolchain_type`
+#     attribute.
+# (4) Register the new toolchain in `//:WORKSPACE.bazel` by adding the
+#     toolchain's label (i.e.
+#     `//bazel/toolchain:<compiler>-<os>-<cpu>-toolchain`) to the
+#     `register_toolchains()` function.
+#
 # For more information on configuring toolchains, see
 # https://bazel.build/tutorials/ccp-toolchain-config
 # and https://bazel.build/extending/toolchains.
@@ -11,6 +38,56 @@ alias(
     actual = "@bazel_tools//tools/cpp:toolchain_type",
 )
 
+#
+# aarch64_linux_gnu_gcc-linux-x86_64
+#
+
+# Toolchain identifier.
+_aarch64_linux_gnu_gcc = "toolchain-aarch64_linux_gnu_gcc-linux-x86_64"
+
+cc_toolchain_config(
+    name = "aarch64_linux_gnu_gcc-linux-x86_64-config",
+    ar = "/usr/bin/aarch64-linux-gnu-ar",
+    cc = "/usr/bin/aarch64-linux-gnu-gcc",
+    compiler = "aarch64-linux-gnu-gcc",
+    compiler_version = "//:aarch64_linux_gnu_gcc_version",
+    ld = "/usr/bin/aarch64-linux-gnu-ld",
+    sys_includes = [
+        "/usr/aarch64-linux-gnu/include",
+        "/usr/lib/gcc/aarch64-linux-gnu/{compiler_version}/include",
+        "/usr/lib/gcc/aarch64-linux-gnu/{compiler_version}/include-fixed",
+    ],
+    target_cpu = "arm64",
+    toolchain_identifier = _aarch64_linux_gnu_gcc,
+)
+
+cc_toolchain(
+    name = "aarch64_linux_gnu_gcc-linux-x86_64",
+    all_files = ":empty",
+    compiler_files = ":empty",
+    dwp_files = ":empty",
+    linker_files = ":empty",
+    objcopy_files = ":empty",
+    strip_files = ":empty",
+    supports_param_files = 0,
+    toolchain_config = ":aarch64_linux_gnu_gcc-linux-x86_64-config",
+    toolchain_identifier = _aarch64_linux_gnu_gcc,
+)
+
+toolchain(
+    name = "aarch64_linux_gnu_gcc-linux-x86_64-toolchain",
+    exec_compatible_with = [
+        "@platforms//os:linux",
+        "@platforms//cpu:x86_64",
+    ],
+    target_compatible_with = [
+        "@platforms//os:linux",
+        "@platforms//cpu:arm64",
+    ],
+    toolchain = ":aarch64_linux_gnu_gcc-linux-x86_64",
+    toolchain_type = ":toolchain_type",
+)
+
 #
 # clang-linux-x86_64
 #
@@ -23,9 +100,10 @@ cc_toolchain_config(
     ar = "/usr/bin/ar",
     cc = "/usr/bin/clang",
     compiler = "clang",
+    compiler_version = "//:clang_version",
     ld = "/usr/bin/ld",
     sys_includes = [
-        "/usr/lib/clang/14.0.6",
+        "/usr/lib/clang/{compiler_version}",
         "/usr/include",
     ],
     target_cpu = "x86_64",
@@ -48,7 +126,6 @@ cc_toolchain(
 toolchain(
     name = "clang-linux-x86_64-toolchain",
     exec_compatible_with = [
-        "//:clang",
         "@platforms//os:linux",
         "@platforms//cpu:x86_64",
     ],
@@ -72,11 +149,11 @@ cc_toolchain_config(
     ar = "/usr/bin/ar",
     cc = "/usr/bin/gcc",
     compiler = "gcc",
+    compiler_version = "//:gcc_version",
     ld = "/usr/bin/ld",
     sys_includes = [
-        # TODO: remove hard-coded version number.
-        "/usr/lib/gcc/x86_64-pc-linux-gnu/12.2.0/include",
-        "/usr/lib/gcc/x86_64-pc-linux-gnu/12.2.0/include-fixed",
+        "/usr/lib/gcc/x86_64-pc-linux-gnu/{compiler_version}/include",
+        "/usr/lib/gcc/x86_64-pc-linux-gnu/{compiler_version}/include-fixed",
         "/usr/include",
     ],
     target_cpu = "x86_64",

bazel/toolchain/cfg.bzl

@@ -1,3 +1,4 @@
+load("@bazel_skylib//rules:common_settings.bzl", "BuildSettingInfo")
 load("@bazel_tools//tools/cpp:cc_toolchain_config_lib.bzl", "tool_path")
 
 def _cc_toolchain_config_impl(ctx):
@@ -7,7 +8,12 @@ def _cc_toolchain_config_impl(ctx):
         ctx = ctx,
         # See https://bazel.build/docs/cc-toolchain-config-reference#features.
         features = [],
-        cxx_builtin_include_directories = ctx.attr.sys_includes,
+        # Replace `{compiler_version}` in all include paths with the value of
+        # the `compiler_version` label.
+        cxx_builtin_include_directories = [
+            path.format(compiler_version = ctx.attr.compiler_version[BuildSettingInfo].value)
+            for path in ctx.attr.sys_includes
+        ],
         toolchain_identifier = ctx.attr.toolchain_identifier,
         target_system_name = ctx.attr.target_system_name,
         target_cpu = ctx.attr.target_cpu,
@@ -58,6 +64,7 @@ cc_toolchain_config = rule(
         "ar": attr.string(mandatory = True),
         "cc": attr.string(mandatory = True),
         "compiler": attr.string(mandatory = True),
+        "compiler_version": attr.label(mandatory = True),
         "ld": attr.string(mandatory = True),
         "target_cpu": attr.string(mandatory = True),
         "toolchain_identifier": attr.string(mandatory = True),

pkg/c3/portable.h

@@ -180,14 +180,6 @@
 #   endif
 
 
-  /** External, OS-independent library dependencies.
-  **/
-    /* The GMP (GNU arbitrary-precision arithmetic) library.
-    ** (Tested with version 4.0.1.)
-    */
-#     include <gmp.h>
-
-
   /** Private C "extensions."
   ***
   *** Except for these and main(), any function, macro, or structure

pkg/noun/imprison.h

@@ -5,6 +5,7 @@
 
 #include "allocate.h"
 #include "c3.h"
+#include "gmp.h"
 #include "types.h"
 
   /**  Structures.

pkg/noun/retrieve.h

@@ -4,6 +4,7 @@
 #define U3_RETRIEVE_H
 
 #include "c3.h"
+#include "gmp.h"
 #include "types.h"
 
     /** u3r_*: read without ever crashing.