native: implement miscellaneous features (#18044)

vlib/v/gen/native/amd64.v

@@ -1314,27 +1314,14 @@ pub fn (mut a Amd64) gen_exit(mut g Gen, node ast.Expr) {
 }
 
 pub fn (mut g Gen) gen_amd64_exit(expr ast.Expr) {
-	// ret value
-	match expr {
-		ast.CallExpr {
-			right := expr.return_type
-			g.n_error('native exit builtin: Unsupported call ${right}')
-		}
-		ast.Ident {
-			g.mov_var_to_reg(.edi, expr as ast.Ident)
-		}
-		ast.IntegerLiteral {
-			g.mov(.edi, expr.val.int())
-		}
-		else {
-			g.n_error('native builtin exit expects a numeric argument')
-		}
-	}
+	g.expr(expr)
+	g.mov_reg(.rdi, .rax)
+
 	if g.pref.os == .windows {
 		g.mov_reg(.rcx, .rdi)
 		g.apicall('ExitProcess')
 	} else {
-		g.mov(.eax, g.nsyscall_exit())
+		g.mov(.rax, g.nsyscall_exit())
 		g.syscall()
 	}
 	g.trap() // should never be reached, just in case
@@ -3396,11 +3383,22 @@ pub fn (mut g Gen) allocate_array(name string, size int, items int) int {
 	return pos
 }
 
+pub fn (mut g Gen) allocate_var_two_step(name string, size int, initial_val int) int {
+	// TODO: replace int by i64 or bigger
+	g.allocate_var(name, size - 8, 0)
+	return g.allocate_var(name, 8, initial_val)
+}
+
 pub fn (mut g Gen) allocate_var(name string, size int, initial_val int) int {
 	if g.pref.arch == .arm64 {
 		// TODO
 		return 0
 	}
+
+	if size > 8 {
+		return g.allocate_var_two_step(name, size, initial_val)
+	}
+
 	padding := (size - g.stack_var_pos % size) % size
 	n := g.stack_var_pos + size + padding
 	is_far_var := n > 0x80 || n < -0x7f
@@ -3412,6 +3410,12 @@ pub fn (mut g Gen) allocate_var(name string, size int, initial_val int) int {
 			g.write8(0xc6)
 			g.write8(0x45 + far_var_offset)
 		}
+		2 {
+			// WORD
+			g.write8(0x66)
+			g.write8(0xc7)
+			g.write8(0x45 + far_var_offset)
+		}
 		4 {
 			// DWORD
 			g.write8(0xc7)
@@ -3442,6 +3446,9 @@ pub fn (mut g Gen) allocate_var(name string, size int, initial_val int) int {
 		1 {
 			g.write8(initial_val)
 		}
+		2 {
+			g.write16(initial_val)
+		}
 		4 {
 			g.write32(initial_val)
 		}

vlib/v/gen/native/gen.v

@@ -839,6 +839,14 @@ pub fn (mut g Gen) gen_print_from_expr(expr ast.Expr, typ ast.Type, name string)
 				g.gen_print(str, fd)
 			}
 		}
+		ast.Nil {
+			str := '0x0'
+			if newline {
+				g.gen_print(str + '\n', fd)
+			} else {
+				g.gen_print(str, fd)
+			}
+		}
 		ast.CharLiteral {
 			str := g.eval_escape_codes(expr.val)
 			if newline {
@@ -1196,7 +1204,7 @@ fn (mut g Gen) stmt(node ast.Stmt) {
 			words := node.val.split(' ')
 			for word in words {
 				if word.len != 2 {
-					g.n_error('opcodes format: xx xx xx xx')
+					g.n_error('opcodes format: xx xx xx xx\nhash statements are not allowed with the native backend, use the C backend for extended C interoperability.')
 				}
 				b := unsafe { C.strtol(&char(word.str), 0, 16) }
 				// b := word.u8()
@@ -1542,6 +1550,9 @@ fn (mut g Gen) expr(node ast.Expr) {
 			g.movabs(.rax, i64(node.val.u64()))
 			// g.gen_print_reg(.rax, 3, fd)
 		}
+		ast.Nil {
+			g.movabs(.rax, 0)
+		}
 		ast.PostfixExpr {
 			g.postfix_expr(node)
 		}

vlib/v/gen/native/tests/pointers.vv

@@ -2,6 +2,7 @@ fn main() {
 	test_eq_ne()
 	test_lt_gt()
 	test_ref_deref()
+	test_nil()
 	println("ok")
 }
 
@@ -66,3 +67,16 @@ fn test_ref_deref() {
 	assert *c == b
 	assert **c == *b
 }
+
+fn test_nil() {
+	unsafe {
+		a := voidptr(nil)
+		b := voidptr(0)
+
+		assert a == b
+		assert a == 0
+		assert b == nil
+
+		println(nil) // currently outputs '0x0' -> should this be 'nil'?
+	}
+}

vlib/v/gen/native/tests/pointers.vv.out

@@ -1 +1,2 @@
+0x0
 ok