checker: disallow address of array and map index outside unsafe (#6557)

vlib/cli/command.v

@@ -148,6 +148,7 @@ fn (mut cmd Command) parse_flags() {
 		}
 		mut found := false
 		for i in 0 .. cmd.flags.len {
+			unsafe {
 			mut flag := &cmd.flags[i]
 			if flag.matches(cmd.args, cmd.flags.have_abbrev()) {
 				found = true
@@ -159,6 +160,7 @@ fn (mut cmd Command) parse_flags() {
 				break
 			}
 		  }
+		}
 		if !found {
 			println('Command `$cmd.name` has no flag `${cmd.args[0]}`')
 			exit(1)

vlib/crypto/internal/subtle/aliasing.v

@@ -16,8 +16,8 @@ pub fn any_overlap(x, y []byte) bool {
 	return x.len > 0 && y.len > 0 &&
 		// &x.data[0] <= &y.data[y.len-1] &&
 		// &y.data[0] <= &x.data[x.len-1]
-		&x[0] <= &y[y.len-1] &&
-		&y[0] <= &x[x.len-1]
+		unsafe { &x[0] <= &y[y.len-1] &&
+		&y[0] <= &x[x.len-1] }
 }
 
 // inexact_overlap reports whether x and y share memory at any non-corresponding
@@ -27,7 +27,7 @@ pub fn any_overlap(x, y []byte) bool {
 // inexact_overlap can be used to implement the requirements of the crypto/cipher
 // AEAD, Block, BlockMode and Stream interfaces.
 pub fn inexact_overlap(x, y []byte) bool {
-	if x.len == 0 || y.len == 0 || &x[0] == &y[0] {
+	if x.len == 0 || y.len == 0 || unsafe { &x[0] == &y[0] } {
 		return false
 	}
 	return any_overlap(x, y)

vlib/regex/regex.v

@@ -1346,7 +1346,7 @@ pub fn (re RE) get_query() string {
 
 	mut i := 0
 	for i < re.prog.len && re.prog[i].ist != ist_prog_end && re.prog[i].ist != 0{
-		tk := &re.prog[i]
+		tk := unsafe { &re.prog[i] }
 		ch := tk.ist
 
 		// GROUP start

vlib/strconv/f32_str.v

@@ -160,7 +160,9 @@ pub fn (d Dec32) get_string_32(neg bool, i_n_digit int, i_pad_digit int) string
 		x++
 	}
 	*/
-	return tos(byteptr(&buf[0]), i)
+	return unsafe {
+		tos(byteptr(&buf[0]), i) 
+	}
 }
 
 fn f32_to_decimal_exact_int(i_mant u32, exp u32) (Dec32,bool) {

vlib/strconv/f64_str.v

@@ -190,7 +190,9 @@ fn (d Dec64) get_string_64(neg bool, i_n_digit int, i_pad_digit int) string {
 		x++
 	}
 	*/
-	return tos(byteptr(&buf[0]), i)
+	return unsafe {
+		tos(byteptr(&buf[0]), i)
+	}
 }
 
 fn f64_to_decimal_exact_int(i_mant u64, exp u64) (Dec64, bool) {

vlib/sync/channels.v

@@ -514,10 +514,14 @@ pub fn channel_select(mut channels []&Channel, dir []Direction, mut objrefs []vo
 			}
 			subscr[i].sem = sem
 			subscr[i].prev = &ch.write_subscriber
+			unsafe {
 				subscr[i].nxt = C.atomic_exchange_ptr(&ch.write_subscriber, &subscr[i])
+			}
 			if voidptr(subscr[i].nxt) != voidptr(0) {
+				unsafe {
 					subscr[i].nxt.prev = &subscr[i]
 				}
+			}
 			C.atomic_store_u16(&ch.write_sub_mtx, u16(0))
 		} else {
 			mut null16 := u16(0)
@@ -526,9 +530,11 @@ pub fn channel_select(mut channels []&Channel, dir []Direction, mut objrefs []vo
 			}
 			subscr[i].sem = sem
 			subscr[i].prev = &ch.read_subscriber
+			unsafe {
 				subscr[i].nxt = C.atomic_exchange_ptr(&ch.read_subscriber, &subscr[i])
+			}
 			if voidptr(subscr[i].nxt) != voidptr(0) {
-				subscr[i].nxt.prev = &subscr[i]
+				unsafe { subscr[i].nxt.prev = &subscr[i] }
 			}
 			C.atomic_store_u16(&ch.read_sub_mtx, u16(0))
 		}

vlib/v/builder/generics.v

@@ -5,7 +5,7 @@ import v.table
 // generic struct instantiations to concrete types
 pub fn (b &Builder) generic_struct_insts_to_concrete() {
 	for idx, _ in b.table.types {
-		mut typ := &b.table.types[idx]
+		mut typ := unsafe { &b.table.types[idx] }
 		if typ.kind == .generic_struct_inst {
 			info := typ.info as table.GenericStructInst
 			parent := b.table.types[info.parent_idx]

vlib/v/checker/checker.v

@@ -123,6 +123,7 @@ pub fn (mut c Checker) check_files(ast_files []ast.File) {
 	mut has_main_fn := false
 	mut files_from_main_module := []&ast.File{}
 	for i in 0 .. ast_files.len {
+		unsafe {
 			file := &ast_files[i]
 			c.check(file)
 			if file.mod.name == 'main' {
@@ -133,6 +134,7 @@ pub fn (mut c Checker) check_files(ast_files []ast.File) {
 				}
 			}
 		}
+	}
 	if has_main_mod_file && !has_main_fn && files_from_main_module.len > 0 {
 		if c.pref.is_script && !c.pref.is_test {
 			mut first_main_file := files_from_main_module[0]
@@ -2746,6 +2748,19 @@ pub fn (mut c Checker) expr(node ast.Expr) table.Type {
 				if node.right is ast.StringLiteral || node.right is ast.StringInterLiteral {
 					c.error('cannot take the address of a string', node.pos)
 				}
+				if node.right is ast.IndexExpr as index {
+					typ_sym := c.table.get_type_symbol(index.left_type)
+					if !c.inside_unsafe {
+						if typ_sym.kind == .map {
+							c.error('cannot get address of map values outside unsafe blocks',
+								index.pos)
+						}
+						if typ_sym.kind == .array {
+							c.error('cannot get address of array elements outside unsafe blocks',
+								index.pos)
+						}
+					}
+				}
 				return right_type.to_ptr()
 			}
 			if node.op == .mul {

vlib/v/compiler_errors_test.v

@@ -88,8 +88,10 @@ fn (mut tasks []TaskDescription) run() {
 		if tasks[i].path in m_skip_files {
 			tasks[i].is_skipped = true
 		}
+		unsafe {
 			work.push(&tasks[i])
 		}
+	}
 	work.close()
 	for _ in 0 .. vjobs {
 		go work_processor(mut work, mut results)

vlib/v/gen/cgen.v

@@ -534,7 +534,7 @@ typedef struct {
 	for typ in g.table.types {
 		match typ.kind {
 			.alias {
-				parent := &g.table.types[typ.parent_idx]
+				parent := unsafe {&g.table.types[typ.parent_idx]}
 				styp := util.no_dots(typ.name)
 				is_c_parent := parent.name.len > 2 && parent.name[0] == `C` && parent.name[1] == `.`
 				parent_styp := if is_c_parent { 'struct ' + util.no_dots(parent.name[2..]) } else { util.no_dots(parent.name) }

vlib/v/table/table.v

@@ -211,7 +211,7 @@ pub fn (t &Table) type_find_method(s &TypeSymbol, name string) ?Fn {
 		if ts.parent_idx == 0 {
 			break
 		}
-		ts = &t.types[ts.parent_idx]
+		ts = unsafe { &t.types[ts.parent_idx] }
 	}
 	return none
 }
@@ -270,7 +270,7 @@ pub fn (t &Table) struct_find_field(s &TypeSymbol, name string) ?Field {
 		if ts.parent_idx == 0 {
 			break
 		}
-		ts = &t.types[ts.parent_idx]
+		ts = unsafe { &t.types[ts.parent_idx] }
 	}
 	return none
 }
@@ -294,7 +294,7 @@ pub fn (t &Table) get_type_symbol(typ Type) &TypeSymbol {
 	// println('get_type_symbol $typ')
 	idx := typ.idx()
 	if idx > 0 {
-		return &t.types[idx]
+		return unsafe{ &t.types[idx] }
 	}
 	// this should never happen
 	panic('get_type_symbol: invalid type (typ=$typ idx=$idx). Compiler bug. This should never happen')
@@ -310,7 +310,7 @@ pub fn (t &Table) get_final_type_symbol(typ Type) &TypeSymbol {
 			alias_info := current_type.info as Alias
 			return t.get_final_type_symbol(alias_info.parent_type)
 		}
-		return &t.types[idx]
+		return unsafe { &t.types[idx] }
 	}
 	// this should never happen
 	panic('get_final_type_symbol: invalid type (typ=$typ idx=$idx). Compiler bug. This should never happen')

vlib/v/tests/unsafe_test.v

@@ -1,7 +1,7 @@
 fn test_ptr_assign() {
 	v := [int(5), 6, 77, 1]
-	mut p := &v[0]
 	unsafe {
+		mut p := &v[0]
 		(*p)++
 		p++ // p now points to v[1]
 		(*p) += 2