authorgravatar for wrongnull@gmail.comBogdan Romanyuk <wrongnull@gmail.com> 2023-11-12 12:03:23+03:00
committergravatar for noreply@github.comGitHub <noreply@github.com> 2023-11-12 11:03:23+02:00
log547481c31c8a538a7badbdce66d81820177ce87f
tree7a5d0fecd2eb0b8eb489ba397b83d056fdb627b0
parent2eeb7358227d13ff4d77ef73c54a0e2ae12c1d58
signaturebadge-question-mark Signed by PGP key 4AEE18F83AFDEB23

Sema: fix comparison with undefined

2 files changed, 34 insertions(+), 10 deletions(-)

src/Sema.zig+24-10
......@@ -8898,10 +8898,16 @@ fn analyzeErrUnionCode(sema: *Sema, block: *Block, src: LazySrcLoc, operand: Air
88988898 const result_ty = operand_ty.errorUnionSet(mod);
88998899
89008900 if (try sema.resolveDefinedValue(block, src, operand)) |val| {
8901 return Air.internedToRef((try mod.intern(.{ .err = .{
8902 .ty = result_ty.toIntern(),
8903 .name = mod.intern_pool.indexToKey(val.toIntern()).error_union.val.err_name,
8904 } })));
8901 switch (mod.intern_pool.indexToKey(val.toIntern()).error_union.val) {
8902 .err_name => |err_name| return Air.internedToRef((try mod.intern(.{ .err = .{
8903 .ty = result_ty.toIntern(),
8904 .name = err_name,
8905 } }))),
8906 .payload => |payload| {
8907 assert(payload.toValue().isUndef(mod));
8908 return mod.undefRef(result_ty);
8909 },
8910 }
89058911 }
89068912
89078913 try sema.requireRuntimeBlock(block, src, null);
......@@ -16413,6 +16419,7 @@ fn zirCmp(
1641316419 const rhs_src: LazySrcLoc = .{ .node_offset_bin_rhs = inst_data.src_node };
1641416420 const lhs = try sema.resolveInst(extra.lhs);
1641516421 const rhs = try sema.resolveInst(extra.rhs);
16422
1641616423 return sema.analyzeCmp(block, src, lhs, rhs, op, lhs_src, rhs_src, false);
1641716424}
1641816425
......@@ -16444,10 +16451,16 @@ fn analyzeCmp(
1644416451 return sema.cmpNumeric(block, src, lhs, rhs, op, lhs_src, rhs_src);
1644516452 }
1644616453 if (is_equality_cmp and lhs_ty.zigTypeTag(mod) == .ErrorUnion and rhs_ty.zigTypeTag(mod) == .ErrorSet) {
16454 if (try sema.resolveValue(lhs)) |lhs_val| {
16455 if (lhs_val.isUndef(mod)) return mod.undefRef(Type.bool);
16456 }
1644716457 const casted_lhs = try sema.analyzeErrUnionCode(block, lhs_src, lhs);
1644816458 return sema.cmpSelf(block, src, casted_lhs, rhs, op, lhs_src, rhs_src);
1644916459 }
1645016460 if (is_equality_cmp and lhs_ty.zigTypeTag(mod) == .ErrorSet and rhs_ty.zigTypeTag(mod) == .ErrorUnion) {
16461 if (try sema.resolveValue(rhs)) |rhs_val| {
16462 if (rhs_val.isUndef(mod)) return mod.undefRef(Type.bool);
16463 }
1645116464 const casted_rhs = try sema.analyzeErrUnionCode(block, rhs_src, rhs);
1645216465 return sema.cmpSelf(block, src, lhs, casted_rhs, op, lhs_src, rhs_src);
1645316466 }
......@@ -16511,11 +16524,9 @@ fn cmpSelf(
1651116524 } else {
1651216525 // For bools, we still check the other operand, because we can lower
1651316526 // bool eq/neq more efficiently.
16514 if (resolved_type.zigTypeTag(mod) == .Bool) {
16515 if (try sema.resolveValue(casted_rhs)) |rhs_val| {
16516 if (rhs_val.isUndef(mod)) return mod.undefRef(Type.bool);
16517 return sema.runtimeBoolCmp(block, src, op, casted_lhs, rhs_val.toBool(), lhs_src);
16518 }
16527 if (try sema.resolveValue(casted_rhs)) |rhs_val| {
16528 if (rhs_val.isUndef(mod)) return mod.undefRef(Type.bool);
16529 if (resolved_type.zigTypeTag(mod) == .Bool) return sema.runtimeBoolCmp(block, src, op, casted_lhs, rhs_val.toBool(), lhs_src);
1651916530 }
1652016531 break :src lhs_src;
1652116532 }
......@@ -38000,7 +38011,10 @@ fn compareVector(
3800038011 const lhs_elem = try lhs.elemValue(sema.mod, i);
3800138012 const rhs_elem = try rhs.elemValue(sema.mod, i);
3800238013 const res_bool = try sema.compareScalar(lhs_elem, op, rhs_elem, ty.scalarType(mod));
38003 scalar.* = try Value.makeBool(res_bool).intern(Type.bool, mod);
38014 scalar.* = if (lhs_elem.isUndef(mod) or rhs_elem.isUndef(mod))
38015 Air.refToInterned(try mod.undefRef(Type.bool)).?
38016 else
38017 try Value.makeBool(res_bool).intern(Type.bool, mod);
3800438018 }
3800538019 return (try mod.intern(.{ .aggregate = .{
3800638020 .ty = (try mod.vectorType(.{ .len = ty.vectorLen(mod), .child = .bool_type })).toIntern(),
test/cases/compile_errors/comparison_with_comptime-known_undefined.zig created+10
......@@ -0,0 +1,10 @@
1pub fn entry() void {
2 var foo: ?*i32 = undefined;
3 if (foo == undefined) {}
4}
5
6// error
7// backend=stage2
8// target=native
9//
10// :3:13: error: use of undefined value here causes undefined behavior