Justify signed integer literal overflow error when most significant bit occupies signed bit

vlib/builtin/int_test.v

@@ -17,7 +17,7 @@ fn test_str_methods() {
 	assert int(1).str() == '1'
 	assert int(-1).str() == '-1'
 	assert int(2147483647).str() == '2147483647'
-	assert int(2147483648).str() == '-2147483648'
+	assert int(u32(2147483648)).str() == '-2147483648'
 	assert int(-2147483648).str() == '-2147483648'
 	assert i64(1).str() == '1'
 	assert i64(-1).str() == '-1'

vlib/builtin/string_int_test.v

@@ -330,8 +330,8 @@ fn test_parse() {
 }
 
 fn test_interpolate_binary_literals() {
-	assert ' 1 ${i64(0b1000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000)}' == ' 1 -9223372036854775808'
-	assert ' 2 ${i64(0b1111_1111_1111_1111_1111_1111_1111_1111_1111_1111_1111_1111_1111_1111_1111_1111)}' == ' 2 -1'
+	assert ' 1 ${i64(u64(0b1000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000))}' == ' 1 -9223372036854775808'
+	assert ' 2 ${i64(u64(0b1111_1111_1111_1111_1111_1111_1111_1111_1111_1111_1111_1111_1111_1111_1111_1111))}' == ' 2 -1'
 	assert ' 3 ${i64(0b0111_1111_1111_1111_1111_1111_1111_1111_1111_1111_1111_1111_1111_1111_1111_1111)}' == ' 3 9223372036854775807'
 	assert ' 4 ${u64(0b1000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000_0000)}' == ' 4 9223372036854775808'
 	assert ' 5 ${u64(0b1111_1111_1111_1111_1111_1111_1111_1111_1111_1111_1111_1111_1111_1111_1111_1111)}' == ' 5 18446744073709551615'

vlib/rand/mt19937/mt19937_test.v

@@ -166,7 +166,7 @@ fn test_mt19937_u64_in_range() {
 
 fn test_mt19937_int31() {
 	max_u31 := int(0x7FFFFFFF)
-	sign_mask := int(0x80000000)
+	sign_mask := int(u32(0x80000000))
 	for seed in seeds {
 		mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
 		rng.seed(seed)
@@ -182,7 +182,7 @@ fn test_mt19937_int31() {
 
 fn test_mt19937_int63() {
 	max_u63 := i64(0x7FFFFFFFFFFFFFFF)
-	sign_mask := i64(0x8000000000000000)
+	sign_mask := i64(u64(0x8000000000000000))
 	for seed in seeds {
 		mut rng := &rand.PRNG(&mt19937.MT19937RNG{})
 		rng.seed(seed)

vlib/rand/musl/musl_rng_test.v

@@ -155,7 +155,7 @@ fn test_musl_u64_in_range() {
 
 fn test_musl_int31() {
 	max_u31 := int(0x7FFFFFFF)
-	sign_mask := int(0x80000000)
+	sign_mask := int(u32(0x80000000))
 	for seed in seeds {
 		mut rng := &rand.PRNG(&musl.MuslRNG{})
 		rng.seed(seed)
@@ -171,7 +171,7 @@ fn test_musl_int31() {
 
 fn test_musl_int63() {
 	max_u63 := i64(0x7FFFFFFFFFFFFFFF)
-	sign_mask := i64(0x8000000000000000)
+	sign_mask := i64(u64(0x8000000000000000))
 	for seed in seeds {
 		mut rng := &rand.PRNG(&musl.MuslRNG{})
 		rng.seed(seed)

vlib/rand/pcg32/pcg32_test.v

@@ -158,7 +158,7 @@ fn test_pcg32_u64_in_range() {
 
 fn test_pcg32_int31() {
 	max_u31 := int(0x7FFFFFFF)
-	sign_mask := int(0x80000000)
+	sign_mask := int(u32(0x80000000))
 	for seed in seeds {
 		mut rng := &rand.PRNG(&pcg32.PCG32RNG{})
 		rng.seed(seed)
@@ -174,7 +174,7 @@ fn test_pcg32_int31() {
 
 fn test_pcg32_int63() {
 	max_u63 := i64(0x7FFFFFFFFFFFFFFF)
-	sign_mask := i64(0x8000000000000000)
+	sign_mask := i64(u64(0x8000000000000000))
 	for seed in seeds {
 		mut rng := &rand.PRNG(&pcg32.PCG32RNG{})
 		rng.seed(seed)

vlib/rand/random_numbers_test.v

@@ -121,7 +121,7 @@ fn test_rand_i64_in_range() {
 
 fn test_rand_int31() {
 	max_u31 := int(0x7FFFFFFF)
-	sign_mask := int(0x80000000)
+	sign_mask := int(u32(0x80000000))
 	for _ in 0 .. rnd_count {
 		value := rand.int31()
 		assert value >= 0
@@ -133,7 +133,7 @@ fn test_rand_int31() {
 
 fn test_rand_int63() {
 	max_u63 := i64(0x7FFFFFFFFFFFFFFF)
-	sign_mask := i64(0x8000000000000000)
+	sign_mask := i64(u64(0x8000000000000000))
 	for _ in 0 .. rnd_count {
 		value := rand.int63()
 		assert value >= 0

vlib/rand/splitmix64/splitmix64_test.v

@@ -155,7 +155,7 @@ fn test_splitmix64_u64_in_range() {
 
 fn test_splitmix64_int31() {
 	max_u31 := int(0x7FFFFFFF)
-	sign_mask := int(0x80000000)
+	sign_mask := int(u32(0x80000000))
 	for seed in seeds {
 		mut rng := &rand.PRNG(&splitmix64.SplitMix64RNG{})
 		rng.seed(seed)
@@ -171,7 +171,7 @@ fn test_splitmix64_int31() {
 
 fn test_splitmix64_int63() {
 	max_u63 := i64(0x7FFFFFFFFFFFFFFF)
-	sign_mask := i64(0x8000000000000000)
+	sign_mask := i64(u64(0x8000000000000000))
 	for seed in seeds {
 		mut rng := &rand.PRNG(&splitmix64.SplitMix64RNG{})
 		rng.seed(seed)

vlib/rand/sys/system_rng_test.v

@@ -253,7 +253,7 @@ fn test_sys_rng_i64_in_range() {
 
 fn test_sys_rng_int31() {
 	max_u31 := int(0x7FFFFFFF)
-	sign_mask := int(0x80000000)
+	sign_mask := int(u32(0x80000000))
 	for seed in seeds {
 		seed_data := [seed]
 		mut rng := &rand.PRNG(&sys.SysRNG{})
@@ -270,7 +270,7 @@ fn test_sys_rng_int31() {
 
 fn test_sys_rng_int63() {
 	max_u63 := i64(0x7FFFFFFFFFFFFFFF)
-	sign_mask := i64(0x8000000000000000)
+	sign_mask := i64(u64(0x8000000000000000))
 	for seed in seeds {
 		seed_data := [seed]
 		mut rng := &rand.PRNG(&sys.SysRNG{})

vlib/rand/wyrand/wyrand_test.v

@@ -155,7 +155,7 @@ fn test_wyrand_u64_in_range() {
 
 fn test_wyrand_int31() {
 	max_u31 := int(0x7FFFFFFF)
-	sign_mask := int(0x80000000)
+	sign_mask := int(u32(0x80000000))
 	for seed in seeds {
 		mut rng := &rand.PRNG(&wyrand.WyRandRNG{})
 		rng.seed(seed)
@@ -171,7 +171,7 @@ fn test_wyrand_int31() {
 
 fn test_wyrand_int63() {
 	max_u63 := i64(0x7FFFFFFFFFFFFFFF)
-	sign_mask := i64(0x8000000000000000)
+	sign_mask := i64(u64(0x8000000000000000))
 	for seed in seeds {
 		mut rng := &rand.PRNG(&wyrand.WyRandRNG{})
 		rng.seed(seed)

vlib/rand/xoroshiro128pp/xoros128pp_test.v

@@ -159,7 +159,7 @@ fn test_xoroshiro128pp_u64_in_range() {
 
 fn test_xoroshiro128pp_int31() {
 	max_u31 := int(0x7FFFFFFF)
-	sign_mask := int(0x80000000)
+	sign_mask := int(u32(0x80000000))
 	for seed in seeds {
 		mut rng := &rand.PRNG(&XOROS128PPRNG{})
 		rng.seed(seed)
@@ -175,7 +175,7 @@ fn test_xoroshiro128pp_int31() {
 
 fn test_xoroshiro128pp_int63() {
 	max_u63 := i64(0x7FFFFFFFFFFFFFFF)
-	sign_mask := i64(0x8000000000000000)
+	sign_mask := i64(u64(0x8000000000000000))
 	for seed in seeds {
 		mut rng := &rand.PRNG(&XOROS128PPRNG{})
 		rng.seed(seed)

vlib/strconv/format.md

@@ -155,7 +155,7 @@ hexadecimal
 import strconv
 
 a1 := u8(0xff)
-b1 := i16(0xffff)
+b1 := i16(u16(0xffff))
 c1 := u32(0xffffffff)
 d1 := u64(-1)
 sc3 := '%hhx %hx %x %lx'

vlib/strconv/format_test.v

@@ -32,7 +32,7 @@ fn test_format() {
 	assert tmp_str == temp_s
 
 	a1 := u8(0xff)
-	b1 := i16(0xffff)
+	b1 := i16(u16(0xffff))
 	c1 := u32(0xffff_ffff)
 	d1 := u64(-1)
 	sc2 := '%hhu %hu %u %lu'

vlib/v/checker/checker.v

@@ -3651,6 +3651,7 @@ fn (mut c Checker) cast_expr(mut node ast.CastExpr) ast.Type {
 		tt := c.table.type_to_str(to_type)
 		tsize, _ := c.table.type_size(to_type.idx_type())
 		bit_size := tsize * 8
+		signed := node.expr.val[0] == `-`
 		value_string := match node.expr.val[0] {
 			`-`, `+` {
 				node.expr.val[1..]
@@ -3659,16 +3660,63 @@ fn (mut c Checker) cast_expr(mut node ast.CastExpr) ast.Type {
 				node.expr.val
 			}
 		}
-		_, e := strconv.common_parse_uint2(value_string, 0, bit_size)
+		mut is_overflowed := false
+		v, e := strconv.common_parse_uint2(value_string, 0, bit_size)
 		match e {
 			0 {}
 			-3 {
+				// FIXME: Once integer literal is considered as hard error, remove this warn and migrate to later error
 				c.error('value `${node.expr.val}` overflows `${tt}`', node.pos)
+				is_overflowed = true
 			}
 			else {
 				c.error('cannot cast value `${node.expr.val}` to `${tt}`', node.pos)
 			}
 		}
+
+		// checks if integer literal's most significant bit
+		// alters sign bit when casting to signed integer
+		if !is_overflowed && to_type.is_signed() {
+			signed_one := match to_type.idx() {
+				ast.char_type_idx, ast.i8_type_idx {
+					u64(0xff)
+				}
+				ast.i16_type_idx {
+					u64(0xffff)
+				}
+				ast.int_type_idx, ast.i32_type_idx {
+					u64(0xffffffff)
+				}
+				ast.i64_type_idx {
+					u64(0xffffffffffffffff)
+				}
+				ast.isize_type_idx {
+					$if x64 {
+						u64(0xffffffffffffffff)
+					} $else {
+						u64(0xffffffff)
+					}
+				}
+				else {
+					c.error('ICE: Not a valid signed type', node.pos)
+					0
+				}
+			}
+			max_signed := (u64(1) << (bit_size - 1)) - 1
+
+			is_overflowed = v == signed_one || (signed && v - 2 == max_signed)
+				|| (!signed && v - 1 == max_signed)
+			// FIXME: Once integer literal is considered as hard error, remove this warn and migrate to later error
+			if is_overflowed {
+				c.warn('value `${node.expr.val}` overflows `${tt}`, this will be considered hard error soon',
+					node.pos)
+			}
+		}
+
+		// FIXME: Once integer literal is considered as hard error, uncomment this
+		// if is_overflowed {
+		// 	c.error('value `${node.expr.val}` overflows `${tt}`', node.pos)
+		// }
 	} else if to_type.is_float() && mut node.expr is ast.FloatLiteral {
 		tt := c.table.type_to_str(to_type)
 		strconv.atof64(node.expr.val) or {

vlib/v/checker/tests/overflow_int_signed_err.out

@@ -0,0 +1,138 @@
+vlib/v/checker/tests/overflow_int_signed_err.vv:2:2: warning: value `0xff` overflows `i8`, this will be considered hard error soon
+    1 | const _i8s = [
+    2 |     i8(0xff), // converted to -1
+      |     ~~~~~~~~
+    3 |     i8(128), // converted to -128
+    4 |     i8(-129), // converted to +127
+vlib/v/checker/tests/overflow_int_signed_err.vv:3:2: warning: value `128` overflows `i8`, this will be considered hard error soon
+    1 | const _i8s = [
+    2 |     i8(0xff), // converted to -1
+    3 |     i8(128), // converted to -128
+      |     ~~~~~~~
+    4 |     i8(-129), // converted to +127
+    5 |     i8(-0xff), // converted to +1
+vlib/v/checker/tests/overflow_int_signed_err.vv:4:2: warning: value `-129` overflows `i8`, this will be considered hard error soon
+    2 |     i8(0xff), // converted to -1
+    3 |     i8(128), // converted to -128
+    4 |     i8(-129), // converted to +127
+      |     ~~~~~~~~
+    5 |     i8(-0xff), // converted to +1
+    6 | ]
+vlib/v/checker/tests/overflow_int_signed_err.vv:5:2: warning: value `-0xff` overflows `i8`, this will be considered hard error soon
+    3 |     i8(128), // converted to -128
+    4 |     i8(-129), // converted to +127
+    5 |     i8(-0xff), // converted to +1
+      |     ~~~~~~~~~
+    6 | ]
+    7 |
+vlib/v/checker/tests/overflow_int_signed_err.vv:9:2: warning: value `0xffff` overflows `i16`, this will be considered hard error soon
+    7 | 
+    8 | const _i16s = [
+    9 |     i16(0xffff), // converted to -1
+      |     ~~~~~~~~~~~
+   10 |     i16(32768), // converted to -32768
+   11 |     i16(-32769), // converted to +32767
+vlib/v/checker/tests/overflow_int_signed_err.vv:10:2: warning: value `32768` overflows `i16`, this will be considered hard error soon
+    8 | const _i16s = [
+    9 |     i16(0xffff), // converted to -1
+   10 |     i16(32768), // converted to -32768
+      |     ~~~~~~~~~~
+   11 |     i16(-32769), // converted to +32767
+   12 |     i16(-0xffff), // converted to +1
+vlib/v/checker/tests/overflow_int_signed_err.vv:11:2: warning: value `-32769` overflows `i16`, this will be considered hard error soon
+    9 |     i16(0xffff), // converted to -1
+   10 |     i16(32768), // converted to -32768
+   11 |     i16(-32769), // converted to +32767
+      |     ~~~~~~~~~~~
+   12 |     i16(-0xffff), // converted to +1
+   13 | ]
+vlib/v/checker/tests/overflow_int_signed_err.vv:12:2: warning: value `-0xffff` overflows `i16`, this will be considered hard error soon
+   10 |     i16(32768), // converted to -32768
+   11 |     i16(-32769), // converted to +32767
+   12 |     i16(-0xffff), // converted to +1
+      |     ~~~~~~~~~~~~
+   13 | ]
+   14 |
+vlib/v/checker/tests/overflow_int_signed_err.vv:16:2: warning: value `0xffffffff` overflows `int`, this will be considered hard error soon
+   14 | 
+   15 | const _ints = [
+   16 |     int(0xffffffff), // converted to -1
+      |     ~~~~~~~~~~~~~~~
+   17 |     int(2147483648), // converted to -2147483648 (overflow in 32-bit int)
+   18 |     int(-2147483649), // converted to +2147483647 (overflow)
+vlib/v/checker/tests/overflow_int_signed_err.vv:17:2: warning: value `2147483648` overflows `int`, this will be considered hard error soon
+   15 | const _ints = [
+   16 |     int(0xffffffff), // converted to -1
+   17 |     int(2147483648), // converted to -2147483648 (overflow in 32-bit int)
+      |     ~~~~~~~~~~~~~~~
+   18 |     int(-2147483649), // converted to +2147483647 (overflow)
+   19 |     int(-0xffffffff), // converted to +1
+vlib/v/checker/tests/overflow_int_signed_err.vv:18:2: warning: value `-2147483649` overflows `int`, this will be considered hard error soon
+   16 |     int(0xffffffff), // converted to -1
+   17 |     int(2147483648), // converted to -2147483648 (overflow in 32-bit int)
+   18 |     int(-2147483649), // converted to +2147483647 (overflow)
+      |     ~~~~~~~~~~~~~~~~
+   19 |     int(-0xffffffff), // converted to +1
+   20 | ]
+vlib/v/checker/tests/overflow_int_signed_err.vv:19:2: warning: value `-0xffffffff` overflows `int`, this will be considered hard error soon
+   17 |     int(2147483648), // converted to -2147483648 (overflow in 32-bit int)
+   18 |     int(-2147483649), // converted to +2147483647 (overflow)
+   19 |     int(-0xffffffff), // converted to +1
+      |     ~~~~~~~~~~~~~~~~
+   20 | ]
+   21 |
+vlib/v/checker/tests/overflow_int_signed_err.vv:23:2: warning: value `0xffffffff` overflows `i32`, this will be considered hard error soon
+   21 | 
+   22 | const _i32s = [
+   23 |     i32(0xffffffff), // converted to -1
+      |     ~~~~~~~~~~~~~~~
+   24 |     i32(2147483648), // converted to -2147483648
+   25 |     i32(-2147483649), // converted to +2147483647
+vlib/v/checker/tests/overflow_int_signed_err.vv:24:2: warning: value `2147483648` overflows `i32`, this will be considered hard error soon
+   22 | const _i32s = [
+   23 |     i32(0xffffffff), // converted to -1
+   24 |     i32(2147483648), // converted to -2147483648
+      |     ~~~~~~~~~~~~~~~
+   25 |     i32(-2147483649), // converted to +2147483647
+   26 |     i32(-0xffffffff), // converted to +1
+vlib/v/checker/tests/overflow_int_signed_err.vv:25:2: warning: value `-2147483649` overflows `i32`, this will be considered hard error soon
+   23 |     i32(0xffffffff), // converted to -1
+   24 |     i32(2147483648), // converted to -2147483648
+   25 |     i32(-2147483649), // converted to +2147483647
+      |     ~~~~~~~~~~~~~~~~
+   26 |     i32(-0xffffffff), // converted to +1
+   27 | ]
+vlib/v/checker/tests/overflow_int_signed_err.vv:26:2: warning: value `-0xffffffff` overflows `i32`, this will be considered hard error soon
+   24 |     i32(2147483648), // converted to -2147483648
+   25 |     i32(-2147483649), // converted to +2147483647
+   26 |     i32(-0xffffffff), // converted to +1
+      |     ~~~~~~~~~~~~~~~~
+   27 | ]
+   28 |
+vlib/v/checker/tests/overflow_int_signed_err.vv:30:2: warning: value `0xffffffffffffffff` overflows `i64`, this will be considered hard error soon
+   28 | 
+   29 | const _i64s = [
+   30 |     i64(0xffffffffffffffff), // converted to -1
+      |     ~~~~~~~~~~~~~~~~~~~~~~~
+   31 |     i64(9223372036854775808), // converted to -9223372036854775808
+   32 |     i64(-9223372036854775809), // converted to +9223372036854775807
+vlib/v/checker/tests/overflow_int_signed_err.vv:31:2: warning: value `9223372036854775808` overflows `i64`, this will be considered hard error soon
+   29 | const _i64s = [
+   30 |     i64(0xffffffffffffffff), // converted to -1
+   31 |     i64(9223372036854775808), // converted to -9223372036854775808
+      |     ~~~~~~~~~~~~~~~~~~~~~~~~
+   32 |     i64(-9223372036854775809), // converted to +9223372036854775807
+   33 |     i64(-0xffffffffffffffff), // converted to +1
+vlib/v/checker/tests/overflow_int_signed_err.vv:32:2: warning: value `-9223372036854775809` overflows `i64`, this will be considered hard error soon
+   30 |     i64(0xffffffffffffffff), // converted to -1
+   31 |     i64(9223372036854775808), // converted to -9223372036854775808
+   32 |     i64(-9223372036854775809), // converted to +9223372036854775807
+      |     ~~~~~~~~~~~~~~~~~~~~~~~~~
+   33 |     i64(-0xffffffffffffffff), // converted to +1
+   34 | ]
+vlib/v/checker/tests/overflow_int_signed_err.vv:33:2: warning: value `-0xffffffffffffffff` overflows `i64`, this will be considered hard error soon
+   31 |     i64(9223372036854775808), // converted to -9223372036854775808
+   32 |     i64(-9223372036854775809), // converted to +9223372036854775807
+   33 |     i64(-0xffffffffffffffff), // converted to +1
+      |     ~~~~~~~~~~~~~~~~~~~~~~~~
+   34 | ]