Support exception handling on windows

spec/compiler/codegen/exception_spec.cr

@@ -1285,4 +1285,20 @@ describe "Code gen: exception" do
       end
       )).to_string.should eq("foo")
   end
+
+  it "codegens return from rescue with value" do
+    run(%(
+      require "prelude"
+
+      def foo
+        begin
+          raise "foo"
+        rescue
+          return 5
+        end
+      end
+
+      foo
+      )).to_i.should eq(5)
+  end
 end

spec/std/dir_spec.cr

@@ -43,7 +43,8 @@ describe "Dir" do
       end
     end
 
-    it "tests empty? on a directory path to a file" do
+    # TODO: do we even want this?
+    pending_win32 "tests empty? on a directory path to a file" do
       ex = expect_raises(Errno, /Error determining size of/) do
         Dir.empty?(datapath("dir", "f1.txt", "/"))
       end

src/compiler/crystal/codegen/call.cr

@@ -459,7 +459,7 @@ class Crystal::CodeGenVisitor
 
     if raises && (rescue_block = @rescue_block)
       invoke_out_block = new_block "invoke_out"
-      @last = builder.invoke func, call_args, invoke_out_block, rescue_block
+      @last = invoke func, call_args, invoke_out_block, rescue_block
       position_at_end invoke_out_block
     else
       @last = call func, call_args

src/compiler/crystal/codegen/codegen.cr

@@ -11,7 +11,6 @@ module Crystal
   MALLOC_NAME        = "__crystal_malloc64"
   MALLOC_ATOMIC_NAME = "__crystal_malloc_atomic64"
   REALLOC_NAME       = "__crystal_realloc64"
-  PERSONALITY_NAME   = "__crystal_personality"
   GET_EXCEPTION_NAME = "__crystal_get_exception"
 
   class Program
@@ -97,6 +96,7 @@ module Crystal
     getter llvm_typer : LLVMTyper
     getter alloca_block : LLVM::BasicBlock
     getter entry_block : LLVM::BasicBlock
+    getter personality_name : String
     property last : LLVM::Value
 
     class LLVMVar
@@ -129,6 +129,7 @@ module Crystal
     @argv : LLVM::Value
     @empty_md_list : LLVM::Value
     @rescue_block : LLVM::BasicBlock?
+    @catch_pad : LLVM::Value?
     @malloc_fun : LLVM::Function?
     @malloc_atomic_fun : LLVM::Function?
     @c_malloc_fun : LLVM::Function?
@@ -156,6 +157,15 @@ module Crystal
       ret_type = @llvm_typer.llvm_return_type(@main_ret_type)
       @main = @llvm_mod.functions.add(MAIN_NAME, [llvm_context.int32, llvm_context.void_pointer.pointer], ret_type)
 
+      if @program.has_flag? "windows"
+        @personality_name = "__CxxFrameHandler3"
+
+        personality_function = @llvm_mod.functions.add(@personality_name, [] of LLVM::Type, llvm_context.int32, true)
+        @main.personality_function = personality_function
+      else
+        @personality_name = "__crystal_personality"
+      end
+
       emit_main_def_debug_metadata(@main, "??") unless @debug.none?
 
       @context = Context.new @main, @program
@@ -282,7 +292,7 @@ module Crystal
 
       def visit(node : FunDef)
         case node.name
-        when MALLOC_NAME, MALLOC_ATOMIC_NAME, REALLOC_NAME, RAISE_NAME, PERSONALITY_NAME, GET_EXCEPTION_NAME
+        when MALLOC_NAME, MALLOC_ATOMIC_NAME, REALLOC_NAME, RAISE_NAME, @codegen.personality_name, GET_EXCEPTION_NAME
           @codegen.accept node
         end
         false
@@ -613,6 +623,12 @@ module Crystal
 
       if return_phi = context.return_phi
         return_phi.add @last, node_type
+      elsif catch_pad = @catch_pad
+        ret_block = new_block "catchret_ret"
+        builder.build_catch_ret catch_pad, ret_block
+
+        position_at_end ret_block
+        codegen_return node_type
       else
         codegen_return node_type
       end
@@ -1518,6 +1534,7 @@ module Crystal
       old_fun = context.fun
       old_ensure_exception_handlers = @ensure_exception_handlers
       old_rescue_block = @rescue_block
+      old_catch_pad = @catch_pad
       old_entry_block = @entry_block
       old_alloca_block = @alloca_block
       old_needs_value = @needs_value
@@ -1528,6 +1545,7 @@ module Crystal
 
       @ensure_exception_handlers = nil
       @rescue_block = nil
+      @catch_pad = nil
 
       block_value = yield
 
@@ -1539,6 +1557,7 @@ module Crystal
       @llvm_typer = old_llvm_typer
       @ensure_exception_handlers = old_ensure_exception_handlers
       @rescue_block = old_rescue_block
+      @catch_pad = old_catch_pad
       @entry_block = old_entry_block
       @alloca_block = old_alloca_block
       @needs_value = old_needs_value

src/compiler/crystal/codegen/crystal_llvm_builder.cr

@@ -41,8 +41,14 @@ module Crystal
       value
     end
 
-    def printf(format, args = [] of LLVM::Value)
-      call @printf, [global_string_pointer(format)] + args
+    def printf(format, args = [] of LLVM::Value, catch_pad = nil)
+      if catch_pad
+        funclet = build_operand_bundle_def("funclet", [catch_pad])
+      else
+        funclet = LLVM::OperandBundleDef.null
+      end
+
+      call @printf, [global_string_pointer(format)] + args, bundle: funclet
     end
 
     def position_at_end(block)
@@ -54,6 +60,10 @@ module Crystal
       @builder.insert_block
     end
 
+    def build_operand_bundle_def(name, values : Array(LLVM::Value))
+      @builder.build_operand_bundle_def(name, values)
+    end
+
     def to_unsafe
       @builder.to_unsafe
     end