Cross build luajit to aarch64-linux from x86 host

.github/workflows/tests.yml

@@ -26,3 +26,23 @@ jobs:
 
     - name: Run tests
       run: make test
+
+  test_cross:
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+        zig: ["0.14.0", "0.15.0-dev.441+c1649d586"]
+
+    runs-on: ${{matrix.os}}
+
+    steps:
+    - name: Clone Ziglua
+      uses: actions/checkout@v3
+
+    - name: Setup Zig
+      uses: mlugg/setup-zig@v1
+      with:
+        version: ${{ matrix.zig }}
+
+    - name: Run tests
+      run: make test_cross

build/lua.zig

@@ -3,6 +3,8 @@ const std = @import("std");
 const Build = std.Build;
 const Step = std.Build.Step;
 
+const applyPatchToFile = @import("utils.zig").applyPatchToFile;
+
 pub const Language = enum {
     lua51,
     lua52,
@@ -98,8 +100,11 @@ pub fn configure(
 
     // Patch ldo.c for Lua 5.1
     if (lang == .lua51) {
-        const patched = patchFile(b, target, lib, upstream.path("src/ldo.c"), b.path("build/lua-5.1.patch"));
-        lib.addCSourceFile(.{ .file = patched, .flags = &flags });
+        const patched = applyPatchToFile(b, b.graph.host, upstream.path("src/ldo.c"), b.path("build/lua-5.1.patch"), "ldo.c");
+
+        lib.step.dependOn(&patched.run.step);
+
+        lib.addCSourceFile(.{ .file = patched.output, .flags = &flags });
     }
 
     lib.linkLibC();
@@ -117,29 +122,6 @@ pub fn configure(
     return lib;
 }
 
-fn patchFile(
-    b: *Build,
-    target: Build.ResolvedTarget,
-    lib: *Step.Compile,
-    file: Build.LazyPath,
-    patch_file: Build.LazyPath,
-) Build.LazyPath {
-    const patch = b.addExecutable(.{
-        .name = "patch",
-        .root_source_file = b.path("build/patch.zig"),
-        .target = target,
-    });
-
-    const patch_run = b.addRunArtifact(patch);
-    patch_run.addFileArg(file);
-    patch_run.addFileArg(patch_file);
-    const out = patch_run.addOutputFileArg("ldo.c");
-
-    lib.step.dependOn(&patch_run.step);
-
-    return out;
-}
-
 const lua_base_source_files = [_][]const u8{
     "src/lapi.c",
     "src/lcode.c",

build/luajit.patch

@@ -0,0 +1,18 @@
+# Patch for cross build on windows
+#  C:\Users\runneradmin\AppData\Local\zig\o\2f9fc57e5a283abd5bd9f55a5d990f42/buildvm_arch.h:8:12: error: \U used with no following hex digits
+# #line 1 "C:\Users\runneradmin\AppData\Local\zig\p\N-V-__8AACcgQgCuLYTPzCp6pnBmFJHyG77RAtM13hjOfTaG\src\vm_arm64.dasc"
+#            ^~~
+# C:\Users\runneradmin\AppData\Local\zig\p\N-V-__8AACcgQgCuLYTPzCp6pnBmFJHyG77RAtM13hjOfTaG\src/host/buildvm.c:75:10: note: in file included from C:\Users\runneradmin\AppData\Local\zig\p\N-V-__8AACcgQgCuLYTPzCp6pnBmFJHyG77RAtM13hjOfTaG\src/host/buildvm.c:75:
+# #include "buildvm_arch.h"
+--- a/dynasm/dynasm.lua
++++ b/dynasm/dynasm.lua
+@@ -85,7 +85,8 @@ end
+ -- Resync CPP line numbers.
+ local function wsync()
+   if g_synclineno ~= g_lineno and g_opt.cpp then
+-    wline("#line "..g_lineno..' "'..g_fname..'"')
++    local fname = gsub(g_fname, "\\", "/")
++    wline("#line "..g_lineno..' "'..fname..'"')
+     g_synclineno = g_lineno
+   end
+ end

build/luajit.zig

@@ -3,6 +3,8 @@ const std = @import("std");
 const Build = std.Build;
 const Step = std.Build.Step;
 
+const applyPatchToFile = @import("utils.zig").applyPatchToFile;
+
 pub fn configure(b: *Build, target: Build.ResolvedTarget, optimize: std.builtin.OptimizeMode, upstream: *Build.Dependency, shared: bool) *Step.Compile {
     // TODO: extract this to the main build function because it is shared between all specialized build functions
 
@@ -24,7 +26,7 @@ pub fn configure(b: *Build, target: Build.ResolvedTarget, optimize: std.builtin.
     // Compile minilua interpreter used at build time to generate files
     const minilua = b.addExecutable(.{
         .name = "minilua",
-        .target = target, // TODO ensure this is the host
+        .target = b.graph.host, // Use host target for cross build
         .optimize = .ReleaseSafe,
     });
     minilua.linkLibC();
@@ -39,7 +41,28 @@ pub fn configure(b: *Build, target: Build.ResolvedTarget, optimize: std.builtin.
 
     // Generate the buildvm_arch.h file using minilua
     const dynasm_run = b.addRunArtifact(minilua);
-    dynasm_run.addFileArg(upstream.path("dynasm/dynasm.lua"));
+
+    if (b.graph.host.result.os.tag == .windows) {
+        // Patch windows cross build for LuaJIT
+        const sourceDynasmFile = upstream.path("dynasm/dynasm.lua");
+        const destDynasmFile = upstream.path("dynasm/dynasm-patched.lua");
+        const patchDynasm = applyPatchToFile(b, b.graph.host, sourceDynasmFile, b.path("build/luajit.patch"), "dynasm-patched.lua");
+
+        const copyPatchedDynasm = b.addSystemCommand(&[_][]const u8{
+            "cmd",
+        });
+        copyPatchedDynasm.addArgs(&.{ "/q", "/c", "copy" });
+        copyPatchedDynasm.step.dependOn(&patchDynasm.run.step);
+        copyPatchedDynasm.addFileArg(patchDynasm.output);
+        copyPatchedDynasm.addFileArg(destDynasmFile);
+
+        dynasm_run.step.dependOn(&patchDynasm.run.step);
+        dynasm_run.step.dependOn(&copyPatchedDynasm.step);
+
+        dynasm_run.addFileArg(destDynasmFile);
+    } else {
+        dynasm_run.addFileArg(upstream.path("dynasm/dynasm.lua"));
+    }
 
     // TODO: Many more flags to figure out
     if (target.result.cpu.arch.endian() == .little) {
@@ -55,6 +78,10 @@ pub fn configure(b: *Build, target: Build.ResolvedTarget, optimize: std.builtin.
         dynasm_run.addArgs(&.{ "-D", "FPU", "-D", "HFABI" });
     }
 
+    if (target.result.cpu.arch == .aarch64 or target.result.cpu.arch == .aarch64_be) {
+        dynasm_run.addArgs(&.{ "-D", "DUALNUM" });
+    }
+
     if (target.result.os.tag == .windows) dynasm_run.addArgs(&.{ "-D", "WIN" });
 
     dynasm_run.addArg("-o");
@@ -81,7 +108,7 @@ pub fn configure(b: *Build, target: Build.ResolvedTarget, optimize: std.builtin.
     // Compile the buildvm executable used to generate other files
     const buildvm = b.addExecutable(.{
         .name = "buildvm",
-        .target = target, // TODO ensure this is the host
+        .target = b.graph.host, // Use host target for cross build
         .optimize = .ReleaseSafe,
     });
     buildvm.linkLibC();
@@ -96,12 +123,18 @@ pub fn configure(b: *Build, target: Build.ResolvedTarget, optimize: std.builtin.
     buildvm.step.dependOn(&dynasm_run.step);
     buildvm.step.dependOn(&genversion_run.step);
 
+    const buildvm_c_flags: []const []const u8 = switch (target.result.cpu.arch) {
+        .aarch64, .aarch64_be => &.{ "-DLUAJIT_TARGET=LUAJIT_ARCH_arm64", "-DLJ_ARCH_HASFPU=1", "-DLJ_ABI_SOFTFP=0" },
+        else => &.{},
+    };
+
     buildvm.addCSourceFiles(.{
         .root = .{ .dependency = .{
             .dependency = upstream,
             .sub_path = "",
         } },
         .files = &.{ "src/host/buildvm_asm.c", "src/host/buildvm_fold.c", "src/host/buildvm_lib.c", "src/host/buildvm_peobj.c", "src/host/buildvm.c" },
+        .flags = buildvm_c_flags,
     });
 
     buildvm.addIncludePath(upstream.path("src"));
@@ -156,7 +189,7 @@ pub fn configure(b: *Build, target: Build.ResolvedTarget, optimize: std.builtin.
 
     buildvm_ljvm.addArg("-o");
     if (target.result.os.tag == .windows) {
-        const ljvm_ob = buildvm_ljvm.addOutputFileArg("lj_vm. o");
+        const ljvm_ob = buildvm_ljvm.addOutputFileArg("lj_vm.o");
         lib.addObjectFile(ljvm_ob);
     } else {
         const ljvm_asm = buildvm_ljvm.addOutputFileArg("lj_vm.S");

build/utils.zig

@@ -0,0 +1,34 @@
+const std = @import("std");
+
+const Build = std.Build;
+const Step = std.Build.Step;
+
+const PatchFile = struct {
+    run: *Step.Run,
+    output: Build.LazyPath,
+};
+
+pub fn applyPatchToFile(
+    b: *Build,
+    target: Build.ResolvedTarget,
+    file: Build.LazyPath,
+    patch_file: Build.LazyPath,
+    output_file: []const u8,
+) PatchFile {
+    const patch = b.addExecutable(.{
+        .name = "patch",
+        .root_source_file = b.path("build/patch.zig"),
+        .target = target,
+    });
+
+    const patch_run = b.addRunArtifact(patch);
+    patch_run.addFileArg(file);
+    patch_run.addFileArg(patch_file);
+
+    const out = patch_run.addOutputFileArg(output_file);
+
+    return .{
+        .run = patch_run,
+        .output = out,
+    };
+}

makefile

@@ -11,5 +11,13 @@ test:
 	zig build install-example-zig-function
 	zig build -Dlang=luau install-example-luau-bytecode
 
+	zig build -Dlang=luajit
+
+test_cross:
+	zig build -Dlang=lua51 -Dtarget=aarch64-linux
+	zig build -Dlang=lua51 -Dtarget=aarch64-linux-gnu
+	zig build -Dlang=luajit -Dtarget=aarch64-linux
+	zig build -Dlang=luajit -Dtarget=aarch64-linux-gnu
+
 docs:
 	zig build docs