Commit 0616d2966a623a005891a2037b49cc2b8ad5b9c4 | zig

author	Veikka Tuominen <git@vexu.eu> 2022-11-16 18:27:17+02:00
committer	Veikka Tuominen <git@vexu.eu> 2022-11-20 20:25:11+02:00
log	0616d2966a623a005891a2037b49cc2b8ad5b9c4
tree	c082e8fc50b9a9035792ec1948c3d5f1ff997a7c
parent	e5a3eb9777ff165d936b0811f3825eabb8bcd6a4

Sema: allow coercing typed undefined to int

Closes #13556

2 files changed, 24 insertions(+), 4 deletions(-)

src
- Sema.zig
test
- behavior
  - cast.zig

src/Sema.zig+16-4

 @@ -24307,7 +24307,10 @@ fn coerceExtra(
         },
         .Int, .ComptimeInt => switch (inst_ty.zigTypeTag()) {
             .Float, .ComptimeFloat => float: {
-                const val = (try sema.resolveDefinedValue(block, inst_src, inst)) orelse {
+                if (is_undef) {
+                    return sema.addConstUndef(dest_ty);
+                }
+                const val = (try sema.resolveMaybeUndefVal(inst)) orelse {
                     if (dest_ty.zigTypeTag() == .ComptimeInt) {
                         if (!opts.report_err) return error.NotCoercible;
                         return sema.failWithNeededComptime(block, inst_src, "value being casted to 'comptime_int' must be comptime-known");
 @@ -24327,7 +24330,10 @@ fn coerceExtra(
                 return try sema.addConstant(dest_ty, result_val);
             },
             .Int, .ComptimeInt => {
-                if (try sema.resolveDefinedValue(block, inst_src, inst)) |val| {
+                if (is_undef) {
+                    return sema.addConstUndef(dest_ty);
+                }
+                if (try sema.resolveMaybeUndefVal(inst)) |val| {
                     // comptime-known integer to other number
                     if (!(try sema.intFitsInType(val, dest_ty, null))) {
                         if (!opts.report_err) return error.NotCoercible;
 @@ -24364,7 +24370,10 @@ fn coerceExtra(
                 return try sema.addConstant(dest_ty, result_val);
             },
             .Float => {
-                if (try sema.resolveDefinedValue(block, inst_src, inst)) |val| {
+                if (is_undef) {
+                    return sema.addConstUndef(dest_ty);
+                }
+                if (try sema.resolveMaybeUndefVal(inst)) |val| {
                     const result_val = try val.floatCast(sema.arena, dest_ty, target);
                     if (!val.eql(result_val, dest_ty, sema.mod)) {
                         return sema.fail(
 @@ -24389,7 +24398,10 @@ fn coerceExtra(
                 }
             },
             .Int, .ComptimeInt => int: {
-                const val = (try sema.resolveDefinedValue(block, inst_src, inst)) orelse {
+                if (is_undef) {
+                    return sema.addConstUndef(dest_ty);
+                }
+                const val = (try sema.resolveMaybeUndefVal(inst)) orelse {
                     if (dest_ty.zigTypeTag() == .ComptimeFloat) {
                         if (!opts.report_err) return error.NotCoercible;
                         return sema.failWithNeededComptime(block, inst_src, "value being casted to 'comptime_float' must be comptime-known");

test/behavior/cast.zig+8

...	@@ -1429,3 +1429,11 @@ test "peer type resolution of function pointer and function body" {	...	@@ -1429,3 +1429,11 @@ test "peer type resolution of function pointer and function body" {
1429	try expect(@TypeOf(a, b) == *const fn () u32);	1429	try expect(@TypeOf(a, b) == *const fn () u32);
1430	try expect(@TypeOf(b, a) == *const fn () u32);	1430	try expect(@TypeOf(b, a) == *const fn () u32);
1431	}	1431	}
		1432
		1433	test "cast typed undefined to int" {
		1434	comptime {
		1435	const a: u16 = undefined;
		1436	const b: u8 = a;
		1437	_ = b;
		1438	}
		1439	}