all: fix fn_or_for_in mut value (part 1) (#8671)

vlib/v/ast/ast.v

@@ -434,6 +434,7 @@ pub:
 	is_mut          bool
 	is_autofree_tmp bool
 	is_arg          bool // fn args should not be autofreed
+	is_auto_deref   bool
 pub mut:
 	typ            table.Type
 	orig_type      table.Type   // original sumtype type; 0 if it's not a sumtype
@@ -1531,3 +1532,14 @@ pub struct Table {
 	// pub mut:
 	// main_fn_decl_node FnDecl
 }
+
+pub fn (expr Expr) is_mut_ident() bool {
+	if expr is Ident {
+		if expr.obj is Var {
+			if expr.obj.is_auto_deref {
+				return true
+			}
+		}
+	}
+	return false
+}

vlib/v/checker/checker.v

@@ -68,8 +68,6 @@ mut:
 	inside_sql                       bool // to handle sql table fields pseudo variables
 	cur_orm_ts                       table.TypeSymbol
 	error_details                    []string
-	for_in_mut_val_name              string
-	fn_mut_arg_names                 []string
 	vmod_file_content                string       // needed for @VMOD_FILE, contents of the file, *NOT its path**
 	vweb_gen_types                   []table.Type // vweb route checks
 	prevent_sum_type_unwrapping_once bool   // needed for assign new values to sum type, stopping unwrapping then
@@ -2745,7 +2743,7 @@ pub fn (mut c Checker) assign_stmt(mut assign_stmt ast.AssignStmt) {
 				right.position())
 		}
 		left_is_ptr := left_type.is_ptr() || left_sym.is_pointer()
-		if left_is_ptr && c.for_in_mut_val_name != left.str() && left.str() !in c.fn_mut_arg_names {
+		if left_is_ptr && !left.is_mut_ident() {
 			if !c.inside_unsafe && assign_stmt.op !in [.assign, .decl_assign] {
 				// ptr op=
 				c.warn('pointer arithmetic is only allowed in `unsafe` blocks', assign_stmt.pos)
@@ -3338,13 +3336,7 @@ fn (mut c Checker) for_in_stmt(mut node ast.ForInStmt) {
 		}
 	}
 	c.check_loop_label(node.label, node.pos)
-	if node.val_is_mut {
-		c.for_in_mut_val_name = node.val_var
-	}
 	c.stmts(node.stmts)
-	if node.val_is_mut {
-		c.for_in_mut_val_name = ''
-	}
 	c.loop_label = prev_loop_label
 	c.in_for_count--
 }
@@ -5845,16 +5837,8 @@ fn (mut c Checker) fn_decl(mut node ast.FnDecl) {
 			}
 		}
 	}
-	for param in node.params {
-		if param.is_mut {
-			c.fn_mut_arg_names << param.name
-		}
-	}
 	c.fn_scope = node.scope
 	c.stmts(node.stmts)
-	if c.fn_mut_arg_names.len > 0 {
-		c.fn_mut_arg_names.clear()
-	}
 	node.has_return = c.returns || has_top_return(node.stmts)
 	if node.language == .v && !node.no_body && node.return_type != table.void_type
 		&& !node.has_return && node.name !in ['panic', 'exit'] {

vlib/v/gen/c/cgen.v

@@ -122,8 +122,6 @@ mut:
 	strs_to_free0         []string // strings.Builder
 	// strs_to_free          []string // strings.Builder
 	inside_call           bool
-	for_in_mut_val_name   string
-	fn_mut_arg_names      []string
 	has_main              bool
 	inside_const          bool
 	comp_for_method       string      // $for method in T.methods {}
@@ -1418,13 +1416,7 @@ fn (mut g Gen) for_in(it ast.ForInStmt) {
 			}
 			g.writeln('DenseArray_value(&$atmp${arw_or_pt}key_values, $idx));')
 		}
-		if it.val_is_mut {
-			g.for_in_mut_val_name = it.val_var
-		}
 		g.stmts(it.stmts)
-		if it.val_is_mut {
-			g.for_in_mut_val_name = ''
-		}
 		if it.key_type == table.string_type && !g.is_builtin_mod {
 			// g.writeln('string_free(&$key);')
 		}
@@ -1471,13 +1463,7 @@ fn (mut g Gen) for_in(it ast.ForInStmt) {
 		s := g.table.type_to_str(it.cond_type)
 		g.error('for in: unhandled symbol `$it.cond` of type `$s`', it.pos)
 	}
-	if it.val_is_mut {
-		g.for_in_mut_val_name = it.val_var
-	}
 	g.stmts(it.stmts)
-	if it.val_is_mut {
-		g.for_in_mut_val_name = ''
-	}
 	if it.label.len > 0 {
 		g.writeln('\t${it.label}__continue: {}')
 	}
@@ -2046,9 +2032,7 @@ fn (mut g Gen) gen_assign_stmt(assign_stmt ast.AssignStmt) {
 				g.array_set_pos = 0
 			} else {
 				g.out.go_back_to(pos)
-				is_var_mut := !is_decl && left is ast.Ident
+				is_var_mut := !is_decl && left.is_mut_ident()
-					&& (g.for_in_mut_val_name == (left as ast.Ident).name
-					|| (left as ast.Ident).name in g.fn_mut_arg_names)
 				addr := if is_var_mut { '' } else { '&' }
 				g.writeln('')
 				g.write('memcpy($addr')
@@ -2119,9 +2103,7 @@ fn (mut g Gen) gen_assign_stmt(assign_stmt ast.AssignStmt) {
 					g.prevent_sum_type_unwrapping_once = true
 				}
 				if !is_fixed_array_copy || is_decl {
-					if !is_decl && var_type != table.string_type_idx && left is ast.Ident
+					if !is_decl && left.is_mut_ident() {
-						&& (g.for_in_mut_val_name == (left as ast.Ident).name
-						|| (left as ast.Ident).name in g.fn_mut_arg_names) {
 						g.write('*')
 					}
 					g.expr(left)

vlib/v/gen/c/fn.v

@@ -170,11 +170,6 @@ fn (mut g Gen) gen_fn_decl(node ast.FnDecl, skip bool) {
 		g.definitions.write(fn_header)
 		g.write(fn_header)
 	}
-	for param in node.params {
-		if param.is_mut {
-			g.fn_mut_arg_names << param.name
-		}
-	}
 	arg_start_pos := g.out.len
 	fargs, fargtypes := g.fn_args(node.params, node.is_variadic)
 	arg_str := g.out.after(arg_start_pos)
@@ -223,9 +218,6 @@ fn (mut g Gen) gen_fn_decl(node ast.FnDecl, skip bool) {
 	g.defer_stmts = []
 	g.stmts(node.stmts)
 	// clear g.fn_mut_arg_names
-	if g.fn_mut_arg_names.len > 0 {
-		g.fn_mut_arg_names.clear()
-	}
 
 	if !node.has_return {
 		g.write_defer_stmts_when_needed()

vlib/v/gen/c/str.v

@@ -343,8 +343,7 @@ fn (mut g Gen) gen_expr_to_string(expr ast.Expr, etype table.Type) {
 	} else if sym_has_str_method
 		|| sym.kind in [.array, .array_fixed, .map, .struct_, .multi_return, .sum_type, .interface_] {
 		is_ptr := typ.is_ptr()
-		is_var_mut := expr is ast.Ident && ((expr as ast.Ident).name == g.for_in_mut_val_name
+		is_var_mut := expr.is_mut_ident()
-			|| (expr as ast.Ident).name in g.fn_mut_arg_names)
 		str_fn_name := g.gen_str_for_type(typ)
 		if is_ptr && !is_var_mut {
 			g.write('_STR("&%.*s\\000", 2, ')

vlib/v/parser/fn.v

@@ -317,6 +317,7 @@ fn (mut p Parser) fn_decl() ast.FnDecl {
 				name: param.name
 				typ: param.typ
 				is_mut: param.is_mut
+				is_auto_deref: param.is_mut
 				pos: param.pos
 				is_used: true
 				is_arg: true

vlib/v/parser/for.v

@@ -157,6 +157,7 @@ fn (mut p Parser) for_stmt() ast.Stmt {
 				name: val_var_name
 				pos: val_var_pos
 				is_mut: val_is_mut
+				is_auto_deref: val_is_mut
 				is_tmp: true
 			})
 		}