v.parser: eliminate PrefixExpr from `&Type(x).name` and `&Type(x)[idx]` too (fix vinix build)

cmd/tools/vast/vast.v

@@ -1224,12 +1224,13 @@ fn (t Tree) at_expr(node ast.AtExpr) &Node {
 fn (t Tree) cast_expr(node ast.CastExpr) &Node {
 	mut obj := new_object()
 	obj.add('ast_type', t.string_node('CastExpr'))
-	obj.add('expr', t.expr(node.expr))
-	obj.add('arg', t.expr(node.arg))
 	obj.add('typ', t.type_node(node.typ))
+	obj.add('ityp', t.number_node(int(node.typ)))
 	obj.add('typname', t.string_node(node.typname))
-	obj.add('expr_type', t.type_node(node.expr_type))
 	obj.add('has_arg', t.bool_node(node.has_arg))
+	obj.add('arg', t.expr(node.arg))
+	obj.add('expr_type', t.type_node(node.expr_type))
+	obj.add('expr', t.expr(node.expr))
 	obj.add('pos', t.position(node.pos))
 	return obj
 }

vlib/v/ast/ast.v

@@ -1101,9 +1101,9 @@ pub:
 pub struct CastExpr {
 pub:
 	arg Expr // `n` in `string(buf, n)`
-	typ Type // `string` TODO rename to `type_to_cast_to`
-	pos token.Position
 pub mut:
+	typ       Type // `string` TODO rename to `type_to_cast_to`
+	pos       token.Position
 	expr      Expr   // `buf` in `string(buf, n)`
 	typname   string // TypeSymbol.name
 	expr_type Type   // `byteptr`

vlib/v/fmt/tests/pointer_casts_keep.vv

@@ -1,4 +1,7 @@
-struct Struct {}
+struct Struct {
+	name string
+	x    int
+}
 
 fn main() {
 	unsafe {
@@ -27,4 +30,21 @@ fn main() {
 		dump(voidptr(ppps))
 		dump(voidptr(pppps))
 	}
+	ss := &Struct{
+		name: 'abc'
+		x: 123
+	}
+	dump(ss)
+	pss := voidptr(ss)
+	if &Struct(pss).name == 'abc' {
+		println('ok')
+	}
+	if &Struct(pss).x == 123 {
+		// &Struct cast and selecting .x
+		println('ok')
+	}
+	if &&Struct(pss) != 0 {
+		// &&Struct
+		println('ok')
+	}
 }

vlib/v/parser/expr.v

@@ -578,15 +578,25 @@ fn (mut p Parser) prefix_expr() ast.Expr {
 	p.next()
 	mut right := p.expr(int(token.Precedence.prefix))
 	p.is_amp = false
-	if mut right is ast.CastExpr && op == .amp {
-		// Handle &Type(x), as well as &&Type(x) etc:
-		mut new_cast_type := right.typ.to_ptr()
-		nct_sym := p.table.get_type_symbol(new_cast_type)
-		return ast.CastExpr{
-			...right
-			typ: new_cast_type
-			typname: nct_sym.name
-			pos: pos.extend(right.pos)
+	if op == .amp {
+		if mut right is ast.CastExpr {
+			// Handle &Type(x), as well as &&Type(x) etc:
+			p.recast_as_pointer(mut right, pos)
+			return right
+		}
+		if mut right is ast.SelectorExpr {
+			// Handle &Type(x).name :
+			if mut right.expr is ast.CastExpr {
+				p.recast_as_pointer(mut right.expr, pos)
+				return right
+			}
+		}
+		if mut right is ast.IndexExpr {
+			// Handle &u64(x)[idx] :
+			if mut right.left is ast.CastExpr {
+				p.recast_as_pointer(mut right.left, pos)
+				return right
+			}
 		}
 	}
 	mut or_stmts := []ast.Stmt{}
@@ -627,3 +637,9 @@ fn (mut p Parser) prefix_expr() ast.Expr {
 		}
 	}
 }
+
+fn (mut p Parser) recast_as_pointer(mut cast_expr ast.CastExpr, pos token.Position) {
+	cast_expr.typ = cast_expr.typ.to_ptr()
+	cast_expr.typname = p.table.get_type_symbol(cast_expr.typ).name
+	cast_expr.pos = pos.extend(cast_expr.pos)
+}

vlib/v/tests/pointers_multilevel_casts_test.v

@@ -1,4 +1,7 @@
-struct Struct {}
+struct Struct {
+	name string
+	x    int
+}
 
 fn test_byte_pointer_casts() {
 	unsafe {
@@ -38,3 +41,36 @@ fn test_struct_pointer_casts() {
 		assert voidptr(pppps).str() == 'c'
 	}
 }
+
+fn test_struct_pointer_casts_with_field_selectors() {
+	ss := &Struct{
+		name: 'abc'
+		x: 123
+	}
+	dump(ss)
+	pss := voidptr(ss)
+	if &Struct(pss).name == 'abc' {
+		assert true
+	}
+	if &Struct(pss).x == 123 {
+		// &Struct cast and selecting .x
+		assert true
+	}
+	if &&Struct(pss) != 0 {
+		// &&Struct
+		assert true
+	}
+}
+
+fn test_pointer_casts_with_indexing() {
+	mut numbers := [5]u64{}
+	numbers[0] = 123
+	numbers[1] = 456
+	unsafe {
+		pnumbers := voidptr(&numbers[0])
+		assert &u64(pnumbers)[0] == 123
+		assert &u64(pnumbers)[1] == 456
+		idx := 1
+		assert &u64(pnumbers)[idx] == 456
+	}
+}