Merge pull request #318 from savi-lang/add/windows

Add support for (cross-compiling to) Windows.

Makefile

@@ -137,7 +137,7 @@ $(eval $(call MAKE_VAR_CACHE_FOR,LLVM_STATIC_RELEASE_URL))
 
 # Specify where to download our pre-built runtime bitcode from.
 # This needs to get bumped explicitly here when we do a new runtime build.
-RUNTIME_BITCODE_RELEASE_URL?=https://github.com/savi-lang/runtime-bitcode/releases/download/20220206
+RUNTIME_BITCODE_RELEASE_URL?=https://github.com/savi-lang/runtime-bitcode/releases/download/v0.20220505.0
 $(eval $(call MAKE_VAR_CACHE_FOR,RUNTIME_BITCODE_RELEASE_URL))
 
 # This is the path where we look for the LLVM pre-built static libraries to be,

main.cr

@@ -21,6 +21,7 @@ module Savi
       option "--llvm-ir", desc: "Write generated LLVM IR to a file", type: Bool, default: false
       option "--llvm-keep-fns", desc: "Don't allow LLVM to remove functions from the output", type: Bool, default: false
       option "--print-perf", desc: "Print compiler performance info", type: Bool, default: false
+      option "-X", "--cross-compile=TRIPLE", desc: "Cross compile to the given target triple"
       option "-C", "--cd=DIR", desc: "Change the working directory"
       option "-p NAME", "--pass=NAME", desc: "Name of the compiler pass to target"
       run do |opts, args|
@@ -33,6 +34,7 @@ module Savi
         options.llvm_keep_fns = true if opts.llvm_keep_fns
         options.auto_fix = true if opts.fix
         options.target_pass = Savi::Compiler.pass_symbol(opts.pass) if opts.pass
+        options.cross_compile = opts.cross_compile.not_nil! if opts.cross_compile
         Dir.cd(opts.cd.not_nil!) if opts.cd
         Cli.compile options, opts.backtrace
       end
@@ -111,6 +113,7 @@ module Savi
         option "--llvm-ir", desc: "Write generated LLVM IR to a file", type: Bool, default: false
         option "--llvm-keep-fns", desc: "Don't allow LLVM to remove functions from the output", type: Bool, default: false
         option "--print-perf", desc: "Print compiler performance info", type: Bool, default: false
+        option "-X", "--cross-compile=TRIPLE", desc: "Cross compile to the given target triple"
         option "-C", "--cd=DIR", desc: "Change the working directory"
         run do |opts, args|
           options = Savi::Compiler::Options.new(
@@ -122,6 +125,7 @@ module Savi
           options.llvm_keep_fns = true if opts.llvm_keep_fns
           options.auto_fix = true if opts.fix
           options.manifest_name = args.name.not_nil! if args.name
+          options.cross_compile = opts.cross_compile.not_nil! if opts.cross_compile
           Dir.cd(opts.cd.not_nil!) if opts.cd
           Cli.compile options, opts.backtrace
         end

src/savi/compiler.cr

@@ -11,6 +11,7 @@ class Savi::Compiler
     property llvm_ir = false
     property llvm_keep_fns = false
     property auto_fix = false
+    property cross_compile : String? = nil
     property manifest_name : String?
     property target_pass : Symbol?
 

src/savi/compiler/binary.cr

@@ -24,6 +24,7 @@ class Savi::Compiler::Binary
   def run(ctx)
     target = Target.new(ctx.code_gen.target_machine.triple)
     bin_path = Binary.path_for(ctx)
+    bin_path += ".exe" if target.windows?
 
     # Compile a temporary binary object file, that we will remove after we
     # use it in the linker invocation to create the final binary.
@@ -36,6 +37,8 @@ class Savi::Compiler::Binary
       link_for_linux_or_bsd(ctx, target, obj_path, bin_path)
     elsif target.macos?
       link_for_macosx(ctx, target, obj_path, bin_path)
+    elsif target.windows?
+      link_for_windows(ctx, target, obj_path, bin_path)
     else
       raise NotImplementedError.new(target.inspect)
     end
@@ -75,7 +78,9 @@ class Savi::Compiler::Binary
 
     # Set up the main library paths.
     # TODO: Support overriding (supplementing?) this via the `SDK_ROOT` env var.
-    each_sysroot_lib_path(target) { |lib_path| link_args << "-L#{lib_path}" }
+    each_sysroot_lib_path(ctx, target) { |lib_path|
+      link_args << "-L#{lib_path}"
+    }
 
     # Link the main system libraries.
     link_args << "-lSystem"
@@ -94,6 +99,29 @@ class Savi::Compiler::Binary
     invoke_linker("mach_o", link_args)
   end
 
+  # Link a EXE executable for a Windows target.
+  def link_for_windows(ctx, target, obj_path, bin_path)
+    link_args = %w{lld-link -nologo -defaultlib:libcmt -defaultlib:oldnames}
+
+    # Set up the main library paths.
+    each_sysroot_lib_path(ctx, target) { |lib_path|
+      link_args << "-libpath:#{lib_path}"
+    }
+
+    # Specify the base set of libraries to link to.
+    link_args << "-defaultlib:libcmt"   # always needed
+    link_args << "-defaultlib:oldnames" # always needed
+    link_args << "-defaultlib:dbghelp"  # used by runtime platform/ponyassert.c
+    link_args << "-defaultlib:ws2_32"   # used by runtime lang/socket.c
+
+    # Finally, specify the input object file and the output filename.
+    link_args << obj_path
+    link_args << "-out:#{bin_path}"
+
+    # Invoke the linker, using the COFF flavor.
+    invoke_linker("coff", link_args)
+  end
+
   # Link an ELF executable for a Linux or FreeBSD target.
   def link_for_linux_or_bsd(ctx, target, obj_path, bin_path)
     link_args = %w{ld.lld}
@@ -118,7 +146,7 @@ class Savi::Compiler::Binary
 
     # Get the list of lib search paths within the sysroot.
     lib_paths = [] of String
-    each_sysroot_lib_path(target) { |path| lib_paths << path }
+    each_sysroot_lib_path(ctx, target) { |path| lib_paths << path }
     lib_paths.each { |lib_path| link_args << "-L#{lib_path}" }
 
     # Also find the mandatory ceremony objects that all programs need to link.
@@ -173,11 +201,11 @@ class Savi::Compiler::Binary
   end
 
   # Yield each sysroot-based path in which to search for linkable libs/objs.
-  def each_sysroot_lib_path(target)
+  def each_sysroot_lib_path(ctx, target)
     sysroot = "/" # TODO: Allow user to supply custom sysroot for cross-compile.
 
     yielded_any = false
-    each_sysroot_lib_glob(target) { |lib_glob|
+    each_sysroot_lib_glob(ctx, target) { |lib_glob|
       Dir.glob(lib_glob) { |lib_path|
         next unless Dir.exists?(lib_path)
 
@@ -190,13 +218,29 @@ class Savi::Compiler::Binary
   end
 
   # Yield each sysroot-based glob used to find paths that exist.
-  def each_sysroot_lib_glob(target)
+  def each_sysroot_lib_glob(ctx, target)
     # For MacOS, we have just one valid sysroot path, so we can finish early.
     if target.macos?
       yield "/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/lib"
       return
     end
 
+    # For Windows we only allow cross compiling and require this env var.
+    if target.windows?
+      unless ctx.options.cross_compile
+        raise NotImplementedError.new("Windows is only supported by cross-compiling.")
+      end
+
+      sdk_root = ENV["SDK_ROOT"]?
+      unless sdk_root
+        raise NotImplementedError.new("The env var `SDK_ROOT` is required to cross-compile to Windows.")
+      end
+
+      yield "#{sdk_root}/**/x86_64"
+      yield "#{sdk_root}/**/x64"
+      return
+    end
+
     if target.linux?
       if target.musl?
         if target.x86_64?

src/savi/compiler/binary_object.cr

@@ -55,6 +55,10 @@ class Savi::Compiler::BinaryObject
       elsif target.arm64?
         return "arm64-apple-macosx"
       end
+    elsif target.windows?
+      if target.x86_64? && target.msvc?
+        return "x86_64-unknown-windows-msvc"
+      end
     end
 
     raise NotImplementedError.new(target.inspect)

src/savi/compiler/code_gen.cr

@@ -92,11 +92,16 @@ class Savi::Compiler::CodeGen
   getter bitwidth
   getter isize
 
-  def initialize(runtime : PonyRT.class | VeronaRT.class = PonyRT)
+  def initialize(
+    runtime : PonyRT.class | VeronaRT.class,
+    options : Compiler::Options
+  )
     LLVM.init_x86
     LLVM.init_aarch64
     LLVM.init_arm
-    @target_triple = LLVM.configured_default_target_triple.as(String)
+    @target_triple = (
+      options.cross_compile || LLVM.configured_default_target_triple
+    ).as(String)
     @target = LLVM::Target.from_triple(@target_triple)
     @target_machine = @target.create_target_machine(@target_triple).as(LLVM::TargetMachine)
     @llvm = LLVM::Context.new
@@ -1021,9 +1026,9 @@ class Savi::Compiler::CodeGen
       when "is_macos"
         gen_bool(target.macos?)
       when "is_posix"
-        gen_bool(true) # TODO: false on windows
+        gen_bool(!target.windows?)
       when "is_windows"
-        gen_bool(false) # TODO: true on windows
+        gen_bool(target.windows?)
       when "is_ilp32"
         gen_bool(abi_size_of(@isize) == 4)
       when "is_lp64"

src/savi/compiler/context.cr

@@ -4,8 +4,8 @@ class Savi::Compiler::Context
   getter program = Program.new
 
   getter classify = Classify::Pass.new
-  getter code_gen = CodeGen.new(CodeGen::PonyRT)
-  getter code_gen_verona = CodeGen.new(CodeGen::VeronaRT)
+  getter code_gen : CodeGen
+  getter code_gen_verona : CodeGen
   getter completeness = Completeness::Pass.new
   getter run = Run.new
   getter flow = Flow::Pass.new
@@ -54,6 +54,8 @@ class Savi::Compiler::Context
   getter errors = [] of Error
 
   def initialize(@compiler, @options = Compiler::Options.new, @prev_ctx = nil)
+    @code_gen = CodeGen.new(CodeGen::PonyRT, @options)
+    @code_gen_verona = CodeGen.new(CodeGen::VeronaRT, @options)
   end
 
   def root_package