mirrors/zig
1
0
Fork 0
mirror of https://codeberg.org/ziglang/zig.git synced 2025-12-06 13:54:21 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

Merge pull request #23263 from mlugg/comptime-field-ptr

Browse source 
Sema: fix pointers to comptime fields of comptime-known aggregate pointers
This commit is contained in:
Matthew Lugg 2025-05-03 20:10:42 +01:00 • committed by GitHub
commit f4e9846bca
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
4 changed files with 79 additions and 33 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

27
src/Sema.zig
View file

@ -27997,12 +27997,17 @@ fn structFieldPtrByIndex(
const zcu = pt.zcu;
const ip = &zcu.intern_pool;
const struct_type = zcu.typeToStruct(struct_ty).?;
const field_is_comptime = struct_type.fieldIsComptime(ip, field_index);
// Comptime fields are handled later
if (!field_is_comptime) {
if (try sema.resolveDefinedValue(block, src, struct_ptr)) |struct_ptr_val| {
const val = try struct_ptr_val.ptrField(field_index, pt);
return Air.internedToRef(val.toIntern());
}
}
const struct_type = zcu.typeToStruct(struct_ty).?;
const field_ty = struct_type.field_types.get(ip)[field_index];
const struct_ptr_ty = sema.typeOf(struct_ptr);
const struct_ptr_ty_info = struct_ptr_ty.ptrInfo(zcu);
@ -28022,6 +28027,7 @@ fn structFieldPtrByIndex(
try Type.fromInterned(struct_ptr_ty_info.child).abiAlignmentSema(pt);
if (struct_type.layout == .@"packed") {
assert(!field_is_comptime);
switch (struct_ty.packedStructFieldPtrInfo(struct_ptr_ty, field_index, pt)) {
.bit_ptr => |packed_offset| {
ptr_ty_data.flags.alignment = parent_align;
@ -28032,6 +28038,7 @@ fn structFieldPtrByIndex(
},
}
} else if (struct_type.layout == .@"extern") {
assert(!field_is_comptime);
// For extern structs, field alignment might be bigger than type's
// natural alignment. Eg, in `extern struct { x: u32, y: u16 }` the
// second field is aligned as u32.
@ -28055,7 +28062,7 @@ fn structFieldPtrByIndex(
const ptr_field_ty = try pt.ptrTypeSema(ptr_ty_data);
if (struct_type.fieldIsComptime(ip, field_index)) {
if (field_is_comptime) {
try struct_ty.resolveStructFieldInits(pt);
const val = try pt.intern(.{ .ptr = .{
.ty = ptr_field_ty.toIntern(),
@ -28602,7 +28609,8 @@ fn tupleFieldPtr(
const pt = sema.pt;
const zcu = pt.zcu;
const tuple_ptr_ty = sema.typeOf(tuple_ptr);
const tuple_ty = tuple_ptr_ty.childType(zcu);
const tuple_ptr_info = tuple_ptr_ty.ptrInfo(zcu);
const tuple_ty: Type = .fromInterned(tuple_ptr_info.child);
try tuple_ty.resolveFields(pt);
const field_count = tuple_ty.structFieldCount(zcu);
@ -28620,9 +28628,16 @@ fn tupleFieldPtr(
const ptr_field_ty = try pt.ptrTypeSema(.{
.child = field_ty.toIntern(),
.flags = .{
.is_const = !tuple_ptr_ty.ptrIsMutable(zcu),
.is_volatile = tuple_ptr_ty.isVolatilePtr(zcu),
.address_space = tuple_ptr_ty.ptrAddressSpace(zcu),
.is_const = tuple_ptr_info.flags.is_const,
.is_volatile = tuple_ptr_info.flags.is_volatile,
.address_space = tuple_ptr_info.flags.address_space,
.alignment = a: {
if (tuple_ptr_info.flags.alignment == .none) break :a .none;
// The tuple pointer isn't naturally aligned, so the field pointer might be underaligned.
const tuple_align = tuple_ptr_info.flags.alignment;
const field_align = try field_ty.abiAlignmentSema(pt);
break :a tuple_align.min(field_align);
},
},
});

40
src/codegen/c.zig
View file

@ -611,7 +611,7 @@ pub const Function = struct {
const a = try Assignment.start(f, writer, ctype);
try f.writeCValue(writer, dst, .Other);
try a.assign(f, writer);
try f.writeCValue(writer, src, .Initializer);
try f.writeCValue(writer, src, .Other);
try a.end(f, writer);
}
@ -2826,7 +2826,7 @@ pub fn genLazyFn(o: *Object, lazy_ctype_pool: *const CType.Pool, lazy_fn: LazyFn
});
try o.dg.renderTypeAndName(w, name_ty, .{ .identifier = "name" }, Const, .none, .complete);
try w.writeAll(" = ");
try o.dg.renderValue(w, Value.fromInterned(name_val), .Initializer);
try o.dg.renderValue(w, Value.fromInterned(name_val), .StaticInitializer);
try w.writeAll(";\n return (");
try o.dg.renderType(w, name_slice_ty);
try w.print("){{{}, {}}};\n", .{
@ -4045,7 +4045,7 @@ fn airStore(f: *Function, inst: Air.Inst.Index, safety: bool) !CValue {
const new_local = try f.allocLocal(inst, src_ty);
try f.writeCValue(writer, new_local, .Other);
try writer.writeAll(" = ");
try f.writeCValue(writer, src_val, .Initializer);
try f.writeCValue(writer, src_val, .Other);
try writer.writeAll(";\n");
break :blk new_local;
@ -4516,7 +4516,7 @@ fn airSlice(f: *Function, inst: Air.Inst.Index) !CValue {
const a = try Assignment.start(f, writer, .usize);
try f.writeCValueMember(writer, local, .{ .identifier = "len" });
try a.assign(f, writer);
try f.writeCValue(writer, len, .Initializer);
try f.writeCValue(writer, len, .Other);
try a.end(f, writer);
}
return local;
@ -4934,7 +4934,7 @@ fn airSwitchDispatch(f: *Function, inst: Air.Inst.Index) !void {
const cond_local = f.loop_switch_conds.get(br.block_inst).?;
try f.writeCValue(writer, .{ .local = cond_local }, .Other);
try writer.writeAll(" = ");
try f.writeCValue(writer, cond, .Initializer);
try f.writeCValue(writer, cond, .Other);
try writer.writeAll(";\n");
try writer.print("goto zig_switch_{d}_loop;", .{@intFromEnum(br.block_inst)});
}
@ -4979,14 +4979,8 @@ fn bitcast(f: *Function, dest_ty: Type, operand: CValue, operand_ty: Type) !CVal
const operand_lval = if (operand == .constant) blk: {
const operand_local = try f.allocLocal(null, operand_ty);
try f.writeCValue(writer, operand_local, .Other);
if (operand_ty.isAbiInt(zcu)) {
try writer.writeAll(" = ");
} else {
try writer.writeAll(" = (");
try f.renderType(writer, operand_ty);
try writer.writeByte(')');
}
try f.writeCValue(writer, operand, .Initializer);
try f.writeCValue(writer, operand, .Other);
try writer.writeAll(";\n");
break :blk operand_local;
} else operand;
@ -5698,7 +5692,7 @@ fn airOptionalPayloadPtrSet(f: *Function, inst: Air.Inst.Index) !CValue {
const a = try Assignment.start(f, writer, opt_ctype);
try f.writeCValueDeref(writer, operand);
try a.assign(f, writer);
try f.object.dg.renderValue(writer, Value.false, .Initializer);
try f.object.dg.renderValue(writer, Value.false, .Other);
try a.end(f, writer);
return .none;
},
@ -5718,7 +5712,7 @@ fn airOptionalPayloadPtrSet(f: *Function, inst: Air.Inst.Index) !CValue {
const a = try Assignment.start(f, writer, opt_ctype);
try f.writeCValueDerefMember(writer, operand, .{ .identifier = "is_null" });
try a.assign(f, writer);
try f.object.dg.renderValue(writer, Value.false, .Initializer);
try f.object.dg.renderValue(writer, Value.false, .Other);
try a.end(f, writer);
}
if (f.liveness.isUnused(inst)) return .none;
@ -5844,7 +5838,7 @@ fn airFieldParentPtr(f: *Function, inst: Air.Inst.Index) !CValue {
try writer.writeByte(')');
switch (fieldLocation(container_ptr_ty, field_ptr_ty, extra.field_index, pt)) {
.begin => try f.writeCValue(writer, field_ptr_val, .Initializer),
.begin => try f.writeCValue(writer, field_ptr_val, .Other),
.field => |field| {
const u8_ptr_ty = try pt.adjustPtrTypeChild(field_ptr_ty, .u8);
@ -5898,7 +5892,7 @@ fn fieldPtr(
try writer.writeByte(')');
switch (fieldLocation(container_ptr_ty, field_ptr_ty, field_index, pt)) {
.begin => try f.writeCValue(writer, container_ptr_val, .Initializer),
.begin => try f.writeCValue(writer, container_ptr_val, .Other),
.field => |field| {
try writer.writeByte('&');
try f.writeCValueDerefMember(writer, container_ptr_val, field);
@ -6021,7 +6015,7 @@ fn airStructFieldVal(f: *Function, inst: Air.Inst.Index) !CValue {
const operand_local = try f.allocLocal(inst, struct_ty);
try f.writeCValue(writer, operand_local, .Other);
try writer.writeAll(" = ");
try f.writeCValue(writer, struct_byval, .Initializer);
try f.writeCValue(writer, struct_byval, .Other);
try writer.writeAll(";\n");
break :blk operand_local;
} else struct_byval;
@ -6119,7 +6113,7 @@ fn airUnwrapErrUnionPay(f: *Function, inst: Air.Inst.Index, is_ptr: bool) !CValu
try writer.writeAll(" = (");
try f.renderType(writer, inst_ty);
try writer.writeByte(')');
try f.writeCValue(writer, operand, .Initializer);
try f.writeCValue(writer, operand, .Other);
try writer.writeAll(";\n");
return local;
}
@ -6164,7 +6158,7 @@ fn airWrapOptional(f: *Function, inst: Air.Inst.Index) !CValue {
const a = try Assignment.start(f, writer, operand_ctype);
try f.writeCValueMember(writer, local, .{ .identifier = "payload" });
try a.assign(f, writer);
try f.writeCValue(writer, operand, .Initializer);
try f.writeCValue(writer, operand, .Other);
try a.end(f, writer);
}
return local;
@ -6365,7 +6359,7 @@ fn airArrayToSlice(f: *Function, inst: Air.Inst.Index) !CValue {
try f.writeCValueMember(writer, local, .{ .identifier = "ptr" });
try a.assign(f, writer);
if (operand == .undef) {
try f.writeCValue(writer, .{ .undef = inst_ty.slicePtrFieldType(zcu) }, .Initializer);
try f.writeCValue(writer, .{ .undef = inst_ty.slicePtrFieldType(zcu) }, .Other);
} else {
const ptr_ctype = try f.ctypeFromType(ptr_ty, .complete);
const ptr_child_ctype = ptr_ctype.info(ctype_pool).pointer.elem_ctype;
@ -6382,7 +6376,7 @@ fn airArrayToSlice(f: *Function, inst: Air.Inst.Index) !CValue {
try writer.writeByte('&');
try f.writeCValueDeref(writer, operand);
try writer.print("[{}]", .{try f.fmtIntLiteral(try pt.intValue(.usize, 0))});
} else try f.writeCValue(writer, operand, .Initializer);
} else try f.writeCValue(writer, operand, .Other);
}
try a.end(f, writer);
}
@ -6912,7 +6906,7 @@ fn airMemset(f: *Function, inst: Air.Inst.Index, safety: bool) !CValue {
try writer.writeAll("for (");
try f.writeCValue(writer, index, .Other);
try writer.writeAll(" = ");
try f.object.dg.renderValue(writer, try pt.intValue(.usize, 0), .Initializer);
try f.object.dg.renderValue(writer, try pt.intValue(.usize, 0), .Other);
try writer.writeAll("; ");
try f.writeCValue(writer, index, .Other);
try writer.writeAll(" != ");
@ -7282,7 +7276,7 @@ fn airReduce(f: *Function, inst: Air.Inst.Index) !CValue {
.float => try pt.floatValue(scalar_ty, std.math.nan(f128)),
else => unreachable,
},
}, .Initializer);
}, .Other);
try writer.writeAll(";\n");
const v = try Vectorize.start(f, inst, writer, operand_ty);

18
test/behavior/tuple.zig
View file

@ -602,3 +602,21 @@ test "empty union in tuple" {
try std.testing.expectEqualStrings("0", info.@"struct".fields[0].name);
try std.testing.expect(@typeInfo(info.@"struct".fields[0].type) == .@"union");
}
test "field pointer of underaligned tuple" {
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest;
const S = struct {
fn doTheTest() !void {
const T = struct { u8, u32 };
var val: T align(2) = .{ 1, 2 };
comptime assert(@TypeOf(&val[0]) == *u8); // `u8` field pointer isn't overaligned
comptime assert(@TypeOf(&val[1]) == *align(2) u32); // `u32` field pointer is correctly underaligned
try expect(val[0] == 1);
try expect(val[1] == 2);
}
};
try S.doTheTest();
try comptime S.doTheTest();
}

19
test/cases/compile_errors/runtime_store_to_comptime_field.zig Normal file
View file

@ -0,0 +1,19 @@
const init: u32 = 1;
fn rt() u32 {
return 3;
}
var tuple_val = .{init};
export fn tuple_field() void {
tuple_val[0] = rt();
}
var struct_val = .{ .x = init };
export fn struct_field() void {
struct_val.x = rt();
}
// error
//
// :8:14: error: cannot store runtime value in compile time variable
// :13:15: error: cannot store runtime value in compile time variable