native: fix small issues noted in vlang#19498

vlib/v/gen/native/amd64.v

@@ -942,6 +942,13 @@ fn (mut c Amd64) call(addr int) i64 {
 	return c_addr
 }
 
+fn (mut c Amd64) patch_relative_jmp(pos int, addr i64) {
+	// Update jmp or cjmp address.
+	// The value is the relative address, difference between current position and the location
+	// after `jxx 00 00 00 00`
+	c.g.write32_at(pos, int(addr - pos - 4))
+}
+
 fn (mut c Amd64) extern_call(addr int) {
 	match c.g.pref.os {
 		.linux {

vlib/v/gen/native/arm64.v

@@ -530,3 +530,7 @@ pub fn (mut c Arm64) add(r Register, val int) {
 fn (mut c Arm64) mov_deref(reg Register, regptr Register, typ ast.Type) {
 	panic('Arm64.mov_deref() not implemented')
 }
+
+fn (mut c Arm64) patch_relative_jmp(pos int, addr i64) {
+	panic('Arm64.patch_relative_jmp() not implemented')
+}

vlib/v/gen/native/comptime.v

@@ -10,30 +10,12 @@ fn (mut g Gen) comptime_at(node ast.AtExpr) string {
 }
 
 fn (mut g Gen) comptime_conditional(node ast.IfExpr) ?ast.IfBranch {
-	if node.branches.len == 0 {
-		return none
-	}
-
-	for i, branch in node.branches {
-		// handle $else branch, which does not have a condition
-		if (node.has_else && i + 1 == node.branches.len) || g.comptime_is_truthy(branch.cond) {
-			return branch
-		}
-	}
-
-	return none
+	return node.branches.filter((node.has_else && it == node.branches.last())
+		|| g.comptime_is_truthy(it.cond))[0] or { return none }
 }
 
 fn (mut g Gen) should_emit_hash_stmt(node ast.HashStmt) bool {
-	if node.ct_conds.len == 0 {
-		return true
-	}
-
-	mut emit := true
-	for cond in node.ct_conds {
-		emit = emit && g.comptime_is_truthy(cond)
-	}
-	return emit
+	return node.ct_conds.all(g.comptime_is_truthy(it))
 }
 
 fn (mut g Gen) comptime_is_truthy(cond ast.Expr) bool {

vlib/v/gen/native/gen.v

@@ -127,6 +127,7 @@ mut:
 	mov(r Register, val int)
 	mov64(r Register, val i64)
 	movabs(reg Register, val i64)
+	patch_relative_jmp(pos int, addr i64)
 	prefix_expr(node ast.PrefixExpr)
 	push(r Register)
 	ret()
@@ -428,17 +429,17 @@ pub fn (mut g Gen) has_external_deps() bool {
 	return g.extern_symbols.len != 0
 }
 
-pub fn (mut g Gen) ast_fetch_external_deps() bool {
+pub fn (mut g Gen) ast_fetch_external_deps() {
 	for file in g.files {
 		g.current_file = file
 		walker.inspect(file, unsafe { &mut g }, node_fetch_external_deps)
 	}
 
-	return g.has_external_deps()
+	g.requires_linking = g.has_external_deps()
 }
 
 pub fn (mut g Gen) generate_header() {
-	g.requires_linking = g.ast_fetch_external_deps()
+	g.ast_fetch_external_deps()
 
 	match g.pref.os {
 		.macos {
@@ -482,13 +483,7 @@ pub fn (mut g Gen) create_executable() {
 	os.write_file_array(obj_name, g.buf) or { panic(err) }
 
 	if g.requires_linking {
-		match g.pref.os {
-			// TEMPORARY
-			.linux { // TEMPORARY
-				g.link(obj_name)
-			} // TEMPORARY
-			else {} // TEMPORARY
-		} // TEMPORARY
+		g.link(obj_name)
 	}
 
 	os.chmod(g.out_name, 0o775) or { panic(err) } // make it executable
@@ -524,6 +519,12 @@ pub fn (mut g Gen) link(obj_name string) {
 		.linux {
 			g.link_elf_file(obj_name)
 		}
+		.windows {
+			// windows linking is alredy done before codegen
+		}
+		.macos {
+			// TODO: implement linking for macos!
+		}
 		else {
 			g.n_error('native linking is not implemented for ${g.pref.os}')
 		}
@@ -564,9 +565,7 @@ pub fn (g &Gen) pos() i64 {
 }
 
 fn (mut g Gen) write(bytes []u8) {
-	for _, b in bytes {
-		g.buf << b
-	}
+	g.buf << bytes
 }
 
 fn (mut g Gen) write8(n int) {
@@ -1034,10 +1033,8 @@ fn (mut g Gen) patch_labels() {
 			g.n_error('label addr = 0')
 			return
 		}
-		// Update jmp or cjmp address.
-		// The value is the relative address, difference between current position and the location
-		// after `jxx 00 00 00 00`
-		g.write32_at(label.pos, int(addr - label.pos - 4))
+
+		g.code_gen.patch_relative_jmp(label.pos, addr)
 	}
 }
 

vlib/v/gen/native/stmt.v

@@ -75,12 +75,11 @@ fn (mut g Gen) stmt(node ast.Stmt) {
 
 			match node.kind {
 				'include', 'preinclude', 'define', 'insert' {
-					g.warning('#${node.kind} is not supported with the native backend',
+					g.v_error('#${node.kind} is not supported with the native backend',
 						node.pos)
-					// TODO: replace with error once issues with builtin are resolved
 				}
 				'flag' {
-					// flags are already handled when dispatching extern dependencies
+					// do nothing; flags are already handled when dispatching extern dependencies
 				}
 				else {
 					g.gen_native_hash_stmt(node)