Vendor lzld

.cargo/config.toml

@@ -11,22 +11,19 @@ rustflags = [
   "link-arg=/STACK:4194304",
 ]
 
-[target.x86_64-apple-darwin]
-linker = "../lzld/lzld"
-rustflags = [
-  "-C",
-  "linker-flavor=ld64.lld",
-  "-C",
-  "link-args=-L/Users/divy/gh/lzld -llzld_x86_64"
-]
+# TODO: build lzld for x86_64
+# [target.x86_64-apple-darwin]
+# linker = "tools/lzld/lzld"
+# rustflags = [
+#   "-C",
+#   "linker-flavor=ld64.lld",
+# ]
 
 [target.aarch64-apple-darwin]
-linker = "../lzld/lzld"
+linker = "tools/lzld/lzld"
 rustflags = [
   "-C",
   "linker-flavor=ld64.lld",
-  "-C",
-  "link-args=-L/Users/divy/gh/lzld -llzld_arm64"
 ]
 
 [target.'cfg(all())']

tools/lzld/.gitignore

@@ -0,0 +1,3 @@
+/target
+
+*.o

tools/lzld/Makefile

@@ -0,0 +1,12 @@
+ARCH = $(shell uname -m)
+
+liblzld_${ARCH}.a: lzld.m
+	cc -c lzld.m -o lzld.o
+	ar rcs liblzld_${ARCH}.a lzld.o
+
+clean:
+	rm -f liblzld_${ARCH}.a lzld.o
+
+all: liblzld_${ARCH}.a
+
+.PHONY: clean all

tools/lzld/README.md

@@ -0,0 +1,39 @@
+A `ld -lazy_framework` for macOS. Designed to build Deno.
+
+## Usage
+
+```toml
+[target.aarch64-apple-darwin]
+rustflags = [
+  "-C",
+  "linker=/path/to/lzld/lzld",
+  "-C",
+  "link-args=-L/path/to/lzld -llzld"
+]
+```
+
+### Usage without `lzld` wrapper
+
+1. `rustc -Z link-native-libraries=no -L/path/to/lzld -llzld`:
+Requires nightly but doesn't need a wrapper linker.
+
+2. Manaully source modification: Remove `#[link]` attributes
+from all dependencies and link to `liblzld.a`.
+
+## Design 
+
+It's pretty simple. Drop in `lzld` as the linker.
+It strips out `-framework` arguments and links a 
+static library (`liblzld.a`) that will lazy load 
+the framework via `dlopen` when needed. 
+
+Rest of the arguments are passed as-is to `lld`.
+
+<!--
+Supported frameworks:
+- QuartzCore
+- CoreFoundation
+- TODO
+-->
+
+

tools/lzld/lzld

@@ -0,0 +1,26 @@
+#!/bin/bash
+set -e
+
+# Find the path to the `lld` binary.
+lld=$(which lld)
+if [ ! -x "$lld" ]; then
+  echo "Error: unable to find 'lld' binary" >&2
+  exit 1
+fi
+
+# Filter out `-framework` arguments.
+args=()
+while [ $# -gt 0 ]; do
+  case "$1" in
+    -framework)
+      shift 2
+      ;;
+    *)
+      args+=("$1")
+      shift
+      ;;
+  esac
+done
+
+# Run `lld` with the filtered arguments.
+exec "$lld" "${args[@]}"

tools/lzld/lzld.m

@@ -0,0 +1,25 @@
+#import <dlfcn.h>
+
+// -- QuartzCore.framework
+
+extern void *kCAGravityTopLeft = 0;
+
+// -- Metal.framework
+
+void *(*MTLCopyAllDevices_)(void) = 0;
+
+void loadMetalFramework() {
+    void *handle = dlopen("/System/Library/Frameworks/Metal.framework/Metal", RTLD_LAZY);
+    if (handle) {
+        MTLCopyAllDevices_ = dlsym(handle, "MTLCopyAllDevices");
+    }
+}
+
+extern void *MTLCopyAllDevices(void) {
+    if (MTLCopyAllDevices_ == 0) {
+        loadMetalFramework();
+    }
+
+    return MTLCopyAllDevices_();
+}
+