urbit · matthew-levan · Nov 16, 2022 · Nov 16, 2022 · Nov 16, 2022 · Nov 16, 2022
diff --git a/BUILD.bazel b/BUILD.bazel
@@ -157,6 +157,14 @@ platform(
     ],
 )
 
+platform(
+    name = "macos-arm64",
+    constraint_values = [
+        "@platforms//os:macos",
+        "@platforms//cpu:arm64",
+    ],
+)
+
 platform(
     name = "clang-macos-arm64",
     constraint_values = [
@@ -167,10 +175,19 @@ platform(
 )
 
 platform(
-    name = "macos-arm64",
+    name = "macos-x86_64",
     constraint_values = [
         "@platforms//os:macos",
-        "@platforms//cpu:arm64",
+        "@platforms//cpu:x86_64",
+    ],
+)
+
+platform(
+    name = "clang-macos-x86_64",
+    constraint_values = [
+        ":clang",
+        "@platforms//os:macos",
+        "@platforms//cpu:x86_64",
     ],
 )
 

diff --git a/README.md b/README.md
@@ -26,6 +26,14 @@ defined in its own package:
 - [`pkg/noun`](pkg/noun): The Nock virtual machine and snapshotting system.
 - [`pkg/vere`](pkg/vere): The I/O drivers, event log, and main event loop.
 
+## Pre-requisites
+
+### macOS
+
+```console
+$ brew install bazelisk automake libtool
+```
+
 ## Build
 
 We use [`bazel`][bazel] to build Urbit's runtime, which is packaged as a single
@@ -39,6 +47,8 @@ will run:
  `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`
+ `clang-macos-arm64`                  | `macos-arm64`   | `clang`
+ `clang-macos-x86_64`                 | `macos-x86_64`  | `clang`
 
 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

diff --git a/WORKSPACE.bazel b/WORKSPACE.bazel
@@ -96,6 +96,7 @@ register_toolchains(
     "//bazel/toolchain:aarch64_linux_gnu_gcc-linux-x86_64-toolchain",
     "//bazel/toolchain:clang-linux-x86_64-toolchain",
     "//bazel/toolchain:clang-macos-arm64-toolchain",
+    "//bazel/toolchain:clang-macos-x86_64-toolchain",
     "//bazel/toolchain:gcc-linux-x86_64-toolchain",
 )
 

diff --git a/bazel/third_party/curl/curl.BUILD b/bazel/third_party/curl/curl.BUILD
@@ -8,7 +8,10 @@ filegroup(
 # TODO: check windows build.
 configure_make(
     name = "curl",
-    args = ["--jobs=`nproc`"],
+    args = select({
+        "@platforms//os:macos": ["--jobs=`sysctl -n hw.logicalcpu`"],
+        "//conditions:default": ["--jobs=`nproc`"],
+    }),
     # We disable unneeded features.
     # TODO: double check that all disabled features below are in fact unneeded.
     configure_options = [

diff --git a/bazel/third_party/gmp/gmp.BUILD b/bazel/third_party/gmp/gmp.BUILD
@@ -8,9 +8,15 @@ filegroup(
 # TODO: check windows build.
 configure_make(
     name = "gmp",
-    args = ["--jobs=`nproc`"],
+    args = select({
+        "@platforms//os:macos": ["--jobs=`sysctl -n hw.logicalcpu`"],
+        "//conditions:default": ["--jobs=`nproc`"],
+    }),
     configure_options = [
         "--disable-shared",
+        # NOTE: --with-pic is required to build PIE binaries on macos_x86_64,
+        # but we leave it in for all builds as a precaution.
+        "--with-pic",
     ] + select({
         # Native compilation on linux-arm64 isn't supported.
         "@//:linux_arm64": ["--host=aarch64-linux-gnu"],

diff --git a/bazel/third_party/openssl/openssl.BUILD b/bazel/third_party/openssl/openssl.BUILD
@@ -8,7 +8,10 @@ filegroup(
 # TODO: use configure_make_variant() to select nmake toolchain on windows?
 configure_make(
     name = "openssl",
-    args = ["--jobs=`nproc`"],
+    args = select({
+        "@platforms//os:macos": ["--jobs=`sysctl -n hw.logicalcpu`"],
+        "//conditions:default": ["--jobs=`nproc`"],
+    }),
     configure_command = select({
         "@platforms//os:windows": "Configure",
         "@//:linux_arm64": "Configure",

diff --git a/bazel/third_party/secp256k1/secp256k1.BUILD b/bazel/third_party/secp256k1/secp256k1.BUILD
@@ -7,7 +7,10 @@ filegroup(
 
 configure_make(
     name = "secp256k1",
-    args = ["--jobs=`nproc`"],
+    args = select({
+        "@platforms//os:macos": ["--jobs=`sysctl -n hw.logicalcpu`"],
+        "//conditions:default": ["--jobs=`nproc`"],
+    }),
     autogen = True,
     configure_in_place = True,
     configure_options = [

diff --git a/bazel/third_party/sigsegv/sigsegv.BUILD b/bazel/third_party/sigsegv/sigsegv.BUILD
@@ -7,7 +7,10 @@ filegroup(
 
 configure_make(
     name = "sigsegv",
-    args = ["--jobs=`nproc`"],
+    args = select({
+        "@platforms//os:macos": ["--jobs=`sysctl -n hw.logicalcpu`"],
+        "//conditions:default": ["--jobs=`nproc`"],
+    }),
     configure_options = [
         "--disable-shared",
         "--enable-static",