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Sema: allow optional pointers in packed structs

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Closes #12572
This commit is contained in:
Veikka Tuominen
2022-08-22 10:17:58 +03:00
parent 74c7782c60
commit b0bcd4add2
3 changed files with 19 additions and 4 deletions
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2
src/Sema.zig
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@@ -20565,8 +20565,8 @@ fn validatePackedType(ty: Type) bool {
.AnyFrame,
.Fn,
.Array,
.Optional,
=> return false,
.Optional => return ty.isPtrLikeOptional(),
.Void,
.Bool,
.Float,

9
src/codegen/llvm.zig
View File

@@ -3417,7 +3417,10 @@ pub const DeclGen = struct {
});
const ty_bit_size = @intCast(u16, field.ty.bitSize(target));
const small_int_ty = dg.context.intType(ty_bit_size);
const small_int_val = non_int_val.constBitCast(small_int_ty);
const small_int_val = if (field.ty.isPtrAtRuntime())
non_int_val.constPtrToInt(small_int_ty)
else
non_int_val.constBitCast(small_int_ty);
const shift_rhs = int_llvm_ty.constInt(running_bits, .False);
// If the field is as large as the entire packed struct, this
// zext would go from, e.g. i16 to i16. This is legal with
@@ -5343,7 +5346,7 @@ pub const FuncGen = struct {
const same_size_int = self.context.intType(elem_bits);
const truncated_int = self.builder.buildTrunc(shifted_value, same_size_int, "");
return self.builder.buildBitCast(truncated_int, elem_llvm_ty, "");
} else if (field_ty.zigTypeTag() == .Pointer) {
} else if (field_ty.isPtrAtRuntime()) {
const elem_bits = @intCast(c_uint, field_ty.bitSize(target));
const same_size_int = self.context.intType(elem_bits);
const truncated_int = self.builder.buildTrunc(shifted_value, same_size_int, "");
@@ -8408,7 +8411,7 @@ pub const FuncGen = struct {
const non_int_val = try self.resolveInst(elem);
const ty_bit_size = @intCast(u16, field.ty.bitSize(target));
const small_int_ty = self.dg.context.intType(ty_bit_size);
const small_int_val = if (field.ty.zigTypeTag() == .Pointer)
const small_int_val = if (field.ty.isPtrAtRuntime())
self.builder.buildPtrToInt(non_int_val, small_int_ty, "")
else
self.builder.buildBitCast(non_int_val, small_int_ty, "");

12
test/behavior/packed-struct.zig
View File

@@ -434,3 +434,15 @@ test "@ptrToInt on a packed struct field" {
};
try expect(@ptrToInt(&S.p0.z) - @ptrToInt(&S.p0.x) == 2);
}
test "optional pointer in packed struct" {
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest;
const T = packed struct { ptr: ?*const u8 };
var n: u8 = 0;
const x = T{ .ptr = &n };
try expect(x.ptr.? == &n);
}