checker: check variable mutability

pull/4341/head
Alexander Medvednikov 2020-04-11 04:09:41 +02:00
parent 9422cd1009
commit 053de0b8e3
6 changed files with 109 additions and 46 deletions

View File

@ -105,6 +105,7 @@ pub:
pos token.Position
comment Comment
default_expr string // token literal //Expr
attr string
mut:
typ table.Type
}
@ -302,6 +303,7 @@ pub:
tok_kind token.Kind
mod string
pos token.Position
is_mut bool
mut:
name string
kind IdentKind

View File

@ -32,7 +32,7 @@ pub fn (node &FnDecl) str(t &table.Table) string {
receiver = '($node.receiver.name $m$name) '
*/
}
name := node.name.after('.')
mut name := node.name.after('.')
if node.is_c {
name = 'C.$name'
}

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@ -74,7 +74,7 @@ pub fn (c mut Checker) check_files(ast_files []ast.File) {
}
}
eprintln('function `main` is undeclared in the main module')
//eprintln(ast_files[0].mod.name)
// eprintln(ast_files[0].mod.name)
exit(1)
}
@ -228,10 +228,22 @@ fn (c mut Checker) assign_expr(assign_expr mut ast.AssignExpr) {
if ast.expr_is_blank_ident(assign_expr.left) {
return
}
match assign_expr.left {
ast.Ident {
scope := c.file.scope.innermost(assign_expr.pos.pos)
if v := scope.find_var(it.name) {
if !v.is_mut {
c.error('`$it.name` is immutable, declare it with `mut`', assign_expr.pos)
}
}
}
else {}
}
if !c.table.check(right_type, left_type) {
left_type_sym := c.table.get_type_symbol(left_type)
right_type_sym := c.table.get_type_symbol(right_type)
c.error('cannot assign `$right_type_sym.name` to variable `${assign_expr.left.str()}` of type `$left_type_sym.name` ', expr_pos(assign_expr.val))
c.error('cannot assign `$right_type_sym.name` to variable `${assign_expr.left.str()}` of type `$left_type_sym.name` ',
expr_pos(assign_expr.val))
}
c.check_expr_opt_call(assign_expr.val, right_type, true)
}
@ -539,10 +551,8 @@ pub fn (c mut Checker) return_stmt(return_stmt mut ast.Return) {
c.error('too many arguments to return, current function does not return anything',
return_stmt.pos)
return
}
else if return_stmt.exprs.len == 0 && c.fn_return_type != table.void_type {
c.error('too few arguments to return',
return_stmt.pos)
} else if return_stmt.exprs.len == 0 && c.fn_return_type != table.void_type {
c.error('too few arguments to return', return_stmt.pos)
return
}
if return_stmt.exprs.len == 0 {
@ -588,11 +598,11 @@ pub fn (c mut Checker) enum_decl(decl ast.EnumDecl) {
ast.IntegerLiteral {}
ast.PrefixExpr {}
else {
pos := expr_pos(field.expr)
mut pos := expr_pos(field.expr)
if pos.pos == 0 {
pos = field.pos
}
c.error("default value for enum has to be an integer", pos)
c.error('default value for enum has to be an integer', pos)
}
}
}
@ -612,12 +622,14 @@ pub fn (c mut Checker) assign_stmt(assign_stmt mut ast.AssignStmt) {
right_type := c.expr(assign_stmt.right[0])
right_type_sym := c.table.get_type_symbol(right_type)
if right_type_sym.kind != .multi_return {
c.error('expression on the right does not return multiple values, while at least $assign_stmt.left.len are expected', assign_stmt.pos)
c.error('expression on the right does not return multiple values, while at least $assign_stmt.left.len are expected',
assign_stmt.pos)
return
}
mr_info := right_type_sym.mr_info()
if mr_info.types.len < assign_stmt.left.len {
c.error('right expression returns only $mr_info.types.len values, but left one expects $assign_stmt.left.len', assign_stmt.pos)
c.error('right expression returns only $mr_info.types.len values, but left one expects $assign_stmt.left.len',
assign_stmt.pos)
}
mut scope := c.file.scope.innermost(assign_stmt.pos.pos)
for i, _ in assign_stmt.left {
@ -730,23 +742,26 @@ pub fn (c mut Checker) array_init(array_init mut ast.ArrayInit) table.Type {
fixed_size = it.val.int()
}
ast.Ident {
//if obj := c.file.global_scope.find_const(it.name) {
//if obj := scope.find(it.name) {
//scope := c.file.scope.innermost(array_init.pos.pos)
//eprintln('scope: ${scope.str()}')
//scope.find(it.name) or {
// c.error('undefined: `$it.name`', array_init.pos)
//}
mut full_const_name := if it.mod == 'main' { it.name } else {it.mod + '.' + it.name }
if obj := c.file.global_scope.find_const( full_const_name ) {
// if obj := c.file.global_scope.find_const(it.name) {
// if obj := scope.find(it.name) {
// scope := c.file.scope.innermost(array_init.pos.pos)
// eprintln('scope: ${scope.str()}')
// scope.find(it.name) or {
// c.error('undefined: `$it.name`', array_init.pos)
// }
mut full_const_name := if it.mod == 'main' { it.name } else { it.mod + '.' +
it.name }
if obj := c.file.global_scope.find_const(full_const_name) {
cf := ast.ConstField(obj)
if cint := is_const_integer(cf) {
fixed_size = cint.val.int()
}
} else {
c.error('non existant integer const $full_const_name while initializing the size of a static array', array_init.pos)
c.error('non existant integer const $full_const_name while initializing the size of a static array',
array_init.pos)
}
} else {
}
else {
c.error('expecting `int` for fixed size', array_init.pos)
}
}
@ -1085,20 +1100,36 @@ pub fn (c mut Checker) expr(node ast.Expr) table.Type {
fn expr_pos(node ast.Expr) token.Position {
// all uncommented have to be implemented
match mut node {
ast.ArrayInit { return it.pos }
ast.AsCast { return it.pos }
ast.AssignExpr { return it.pos }
ast.Assoc { return it.pos }
// ast.BoolLiteral { }
// ast.CastExpr { }
ast.CallExpr { return it.pos }
// ast.CharLiteral { }
ast.EnumVal { return it.pos }
// ast.FloatLiteral { }
ast.ArrayInit {
return it.pos
}
ast.AsCast {
return it.pos
}
// ast.Ident { }
ast.IfExpr { return it.pos }
ast.AssignExpr {
return it.pos
}
// ast.CastExpr { }
ast.Assoc {
return it.pos
}
// ast.BoolLiteral { }
ast.CallExpr {
return it.pos
}
// ast.CharLiteral { }
ast.EnumVal {
return it.pos
}
// ast.FloatLiteral { }
ast.IfExpr {
return it.pos
}
// ast.IfGuardExpr { }
ast.IndexExpr { return it.pos }
ast.IndexExpr {
return it.pos
}
ast.InfixExpr {
left_pos := expr_pos(it.left)
right_pos := expr_pos(it.right)
@ -1111,21 +1142,41 @@ fn expr_pos(node ast.Expr) token.Position {
len: right_pos.pos - left_pos.pos + right_pos.len
}
}
ast.IntegerLiteral { return it.pos }
ast.MapInit { return it.pos }
ast.MatchExpr { return it.pos }
ast.PostfixExpr { return it.pos }
ast.PrefixExpr { return it.pos }
ast.IntegerLiteral {
return it.pos
}
ast.MapInit {
return it.pos
}
ast.MatchExpr {
return it.pos
}
ast.PostfixExpr {
return it.pos
}
// ast.None { }
ast.PrefixExpr {
return it.pos
}
// ast.ParExpr { }
ast.SelectorExpr { return it.pos }
ast.SelectorExpr {
return it.pos
}
// ast.SizeOf { }
ast.StringLiteral { return it.pos }
ast.StringInterLiteral { return it.pos }
ast.StructInit { return it.pos }
ast.StringLiteral {
return it.pos
}
ast.StringInterLiteral {
return it.pos
}
// ast.Type { }
ast.StructInit {
return it.pos
}
// ast.TypeOf { }
else { return token.Position{} }
else {
return token.Position{}
}
}
}

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@ -574,8 +574,15 @@ fn (f mut Fmt) expr(node ast.Expr) {
if branch.stmts.len == 0 {
f.writeln(' {}')
} else {
// TODO single line branches
// if branch.stmts.len < 2 {
// f.write(' { ')
// } else {
f.writeln(' {')
// f.single_line_if = true
// }
f.stmts(branch.stmts)
// f.single_line_if = false
f.writeln('}')
}
}

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@ -1307,7 +1307,7 @@ fn (p mut Parser) array_init() ast.ArrayInit {
mut array_type := table.void_type
mut elem_type := table.void_type
mut exprs := []ast.Expr
is_fixed := false
mut is_fixed := false
if p.tok.kind == .rsbr {
// []typ => `[]` and `typ` must be on the same line
line_nr := p.tok.line_nr
@ -1685,6 +1685,7 @@ fn (p mut Parser) parse_assign_lhs() []ast.Ident {
p.check(.key_static)
}
mut ident := p.parse_ident(false)
ident.is_mut = is_mut
ident.info = ast.IdentVar{
is_mut: is_mut
is_static: is_static
@ -1741,10 +1742,12 @@ fn (p mut Parser) assign_stmt() ast.Stmt {
p.scope.register(ident.name, ast.Var{
name: ident.name
expr: exprs[i]
is_mut: ident.is_mut || p.inside_for
})
} else {
p.scope.register(ident.name, ast.Var{
name: ident.name
is_mut: ident.is_mut || p.inside_for
})
}
}

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@ -728,7 +728,7 @@ pub fn (s mut Scanner) scan() token.Token {
start := s.pos + 1
s.ignore_line()
s.line_comment = s.text[start + 1..s.pos]
comment := s.line_comment.trim_space()
mut comment := s.line_comment.trim_space()
s.pos--
// fix line_nr, \n was read, and the comment is marked
// on the next line