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Revert "Merge pull request #15995 from mlugg/fix/union-field-ptr-align"
This reverts commit 40cf3f7, reversing changes made to d981474.
1 parent 1a2468a commit 43c98dc

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5 files changed

+9
-231
lines changed

5 files changed

+9
-231
lines changed

‎lib/std/pdb.zig

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -776,8 +776,8 @@ pub const Pdb = struct {
776776
} else 0;
777777

778778
const found_line_index = start_line_index + line_entry_idx * @sizeOf(LineNumberEntry);
779-
const line_num_entry: *align(1) LineNumberEntry = @ptrCast(&subsect_info[found_line_index]);
780-
const flags: *align(1) LineNumberEntry.Flags = @ptrCast(&line_num_entry.Flags);
779+
const line_num_entry = @as(*align(1) LineNumberEntry, @ptrCast(&subsect_info[found_line_index]));
780+
const flags = @as(*LineNumberEntry.Flags, @ptrCast(&line_num_entry.Flags));
781781

782782
return debug.LineInfo{
783783
.file_name = source_file_name,

‎src/Module.zig

Lines changed: 0 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -992,7 +992,6 @@ pub const Struct = struct {
992992
is_comptime: bool,
993993

994994
/// Returns the field alignment. If the struct is packed, returns 0.
995-
/// Keep implementation in sync with `Sema.structFieldAlignment`.
996995
pub fn alignment(
997996
field: Field,
998997
mod: *Module,

‎src/Sema.zig

Lines changed: 7 additions & 42 deletions
Original file line numberDiff line numberDiff line change
@@ -25879,9 +25879,6 @@ fn structFieldPtrByIndex(
2587925879

2588025880
const target = mod.getTarget();
2588125881

25882-
const parent_align = struct_ptr_ty_info.flags.alignment.toByteUnitsOptional() orelse
25883-
try sema.typeAbiAlignment(struct_ptr_ty_info.child.toType());
25884-
2588525882
if (struct_obj.layout == .Packed) {
2588625883
comptime assert(Type.packed_struct_layout_version == 2);
2588725884

@@ -25903,6 +25900,8 @@ fn structFieldPtrByIndex(
2590325900
ptr_ty_data.packed_offset.bit_offset += struct_ptr_ty_info.packed_offset.bit_offset;
2590425901
}
2590525902

25903+
const parent_align = struct_ptr_ty_info.flags.alignment.toByteUnitsOptional() orelse
25904+
struct_ptr_ty_info.child.toType().abiAlignment(mod);
2590625905
ptr_ty_data.flags.alignment = Alignment.fromByteUnits(parent_align);
2590725906

2590825907
// If the field happens to be byte-aligned, simplify the pointer type.
@@ -25926,13 +25925,8 @@ fn structFieldPtrByIndex(
2592625925
ptr_ty_data.packed_offset = .{ .host_size = 0, .bit_offset = 0 };
2592725926
}
2592825927
}
25929-
} else if (struct_obj.layout == .Extern and field_index == 0) {
25930-
// This is the first field in memory, so can inherit the struct alignment
25931-
ptr_ty_data.flags.alignment = Alignment.fromByteUnits(parent_align);
2593225928
} else {
25933-
// Our alignment is capped at the field alignment
25934-
const field_align = try sema.structFieldAlignment(field, struct_obj.layout);
25935-
ptr_ty_data.flags.alignment = Alignment.fromByteUnits(@min(field_align, parent_align));
25929+
ptr_ty_data.flags.alignment = field.abi_align;
2593625930
}
2593725931

2593825932
const ptr_field_ty = try mod.ptrType(ptr_ty_data);
@@ -26103,24 +26097,17 @@ fn unionFieldPtr(
2610326097
assert(unresolved_union_ty.zigTypeTag(mod) == .Union);
2610426098

2610526099
const union_ptr_ty = sema.typeOf(union_ptr);
26106-
const union_ptr_info = union_ptr_ty.ptrInfo(mod);
2610726100
const union_ty = try sema.resolveTypeFields(unresolved_union_ty);
2610826101
const union_obj = mod.typeToUnion(union_ty).?;
2610926102
const field_index = try sema.unionFieldIndex(block, union_ty, field_name, field_name_src);
2611026103
const field = union_obj.fields.values()[field_index];
2611126104
const ptr_field_ty = try mod.ptrType(.{
2611226105
.child = field.ty.toIntern(),
2611326106
.flags = .{
26114-
.is_const = union_ptr_info.flags.is_const,
26115-
.is_volatile = union_ptr_info.flags.is_volatile,
26116-
.address_space = union_ptr_info.flags.address_space,
26117-
.alignment = if (union_obj.layout == .Auto) blk: {
26118-
const union_align = union_ptr_info.flags.alignment.toByteUnitsOptional() orelse try sema.typeAbiAlignment(union_ty);
26119-
const field_align = try sema.unionFieldAlignment(field);
26120-
break :blk InternPool.Alignment.fromByteUnits(@min(union_align, field_align));
26121-
} else union_ptr_info.flags.alignment,
26122-
},
26123-
.packed_offset = union_ptr_info.packed_offset,
26107+
.is_const = !union_ptr_ty.ptrIsMutable(mod),
26108+
.is_volatile = union_ptr_ty.isVolatilePtr(mod),
26109+
.address_space = union_ptr_ty.ptrAddressSpace(mod),
26110+
},
2612426111
});
2612526112
const enum_field_index = @as(u32, @intCast(union_obj.tag_ty.enumFieldIndex(field_name, mod).?));
2612626113

@@ -35987,28 +35974,6 @@ fn unionFieldAlignment(sema: *Sema, field: Module.Union.Field) !u32 {
3598735974
field.abi_align.toByteUnitsOptional() orelse try sema.typeAbiAlignment(field.ty)));
3598835975
}
3598935976

35990-
/// Keep implementation in sync with `Module.Struct.Field.alignment`.
35991-
fn structFieldAlignment(sema: *Sema, field: Module.Struct.Field, layout: std.builtin.Type.ContainerLayout) !u32 {
35992-
const mod = sema.mod;
35993-
if (field.abi_align.toByteUnitsOptional()) |a| {
35994-
assert(layout != .Packed);
35995-
return @as(u32, @intCast(a));
35996-
}
35997-
switch (layout) {
35998-
.Packed => return 0,
35999-
.Auto => if (mod.getTarget().ofmt != .c) {
36000-
return sema.typeAbiAlignment(field.ty);
36001-
},
36002-
.Extern => {},
36003-
}
36004-
// extern
36005-
const ty_abi_align = try sema.typeAbiAlignment(field.ty);
36006-
if (field.ty.isAbiInt(mod) and field.ty.intInfo(mod).bits >= 128) {
36007-
return @max(ty_abi_align, 16);
36008-
}
36009-
return ty_abi_align;
36010-
}
36011-
3601235977
/// Synchronize logic with `Type.isFnOrHasRuntimeBits`.
3601335978
pub fn fnHasRuntimeBits(sema: *Sema, ty: Type) CompileError!bool {
3601435979
const mod = sema.mod;

‎test/behavior/struct.zig

Lines changed: 0 additions & 77 deletions
Original file line numberDiff line numberDiff line change
@@ -1,7 +1,6 @@
11
const std = @import("std");
22
const builtin = @import("builtin");
33
const native_endian = builtin.target.cpu.arch.endian();
4-
const assert = std.debug.assert;
54
const expect = std.testing.expect;
65
const expectEqual = std.testing.expectEqual;
76
const expectEqualSlices = std.testing.expectEqualSlices;
@@ -1635,79 +1634,3 @@ test "instantiate struct with comptime field" {
16351634
comptime std.debug.assert(things.foo == 1);
16361635
}
16371636
}
1638-
1639-
test "struct field pointer has correct alignment" {
1640-
if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
1641-
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
1642-
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
1643-
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
1644-
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
1645-
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
1646-
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest; // TODO
1647-
1648-
const S = struct {
1649-
fn doTheTest() !void {
1650-
var a: struct { x: u32 } = .{ .x = 123 };
1651-
var b: struct { x: u32 } align(1) = .{ .x = 456 };
1652-
var c: struct { x: u32 } align(64) = .{ .x = 789 };
1653-
1654-
const ap = &a.x;
1655-
const bp = &b.x;
1656-
const cp = &c.x;
1657-
1658-
comptime assert(@TypeOf(ap) == *u32);
1659-
comptime assert(@TypeOf(bp) == *align(1) u32);
1660-
comptime assert(@TypeOf(cp) == *u32); // undefined layout, cannot inherit larger alignment
1661-
1662-
try expectEqual(@as(u32, 123), ap.*);
1663-
try expectEqual(@as(u32, 456), bp.*);
1664-
try expectEqual(@as(u32, 789), cp.*);
1665-
}
1666-
};
1667-
1668-
try S.doTheTest();
1669-
try comptime S.doTheTest();
1670-
}
1671-
1672-
test "extern struct field pointer has correct alignment" {
1673-
if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
1674-
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
1675-
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
1676-
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
1677-
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
1678-
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
1679-
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest; // TODO
1680-
1681-
const S = struct {
1682-
fn doTheTest() !void {
1683-
var a: extern struct { x: u32, y: u32 } = .{ .x = 1, .y = 2 };
1684-
var b: extern struct { x: u32, y: u32 } align(1) = .{ .x = 3, .y = 4 };
1685-
var c: extern struct { x: u32, y: u32 } align(64) = .{ .x = 5, .y = 6 };
1686-
1687-
const axp = &a.x;
1688-
const bxp = &b.x;
1689-
const cxp = &c.x;
1690-
const ayp = &a.y;
1691-
const byp = &b.y;
1692-
const cyp = &c.y;
1693-
1694-
comptime assert(@TypeOf(axp) == *u32);
1695-
comptime assert(@TypeOf(bxp) == *align(1) u32);
1696-
comptime assert(@TypeOf(cxp) == *align(64) u32); // first field, inherits larger alignment
1697-
comptime assert(@TypeOf(ayp) == *u32);
1698-
comptime assert(@TypeOf(byp) == *align(1) u32);
1699-
comptime assert(@TypeOf(cyp) == *u32);
1700-
1701-
try expectEqual(@as(u32, 1), axp.*);
1702-
try expectEqual(@as(u32, 3), bxp.*);
1703-
try expectEqual(@as(u32, 5), cxp.*);
1704-
1705-
try expectEqual(@as(u32, 2), ayp.*);
1706-
try expectEqual(@as(u32, 4), byp.*);
1707-
try expectEqual(@as(u32, 6), cyp.*);
1708-
}
1709-
};
1710-
1711-
try S.doTheTest();
1712-
try comptime S.doTheTest();
1713-
}

‎test/behavior/union.zig

Lines changed: 0 additions & 109 deletions
Original file line numberDiff line numberDiff line change
@@ -1583,112 +1583,3 @@ test "coerce enum literal to union in result loc" {
15831583
try U.doTest(true);
15841584
try comptime U.doTest(true);
15851585
}
1586-
1587-
test "defined-layout union field pointer has correct alignment" {
1588-
if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
1589-
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
1590-
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
1591-
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
1592-
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
1593-
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
1594-
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest; // TODO
1595-
1596-
const S = struct {
1597-
fn doTheTest(comptime U: type) !void {
1598-
var a: U = .{ .x = 123 };
1599-
var b: U align(1) = .{ .x = 456 };
1600-
var c: U align(64) = .{ .x = 789 };
1601-
1602-
const ap = &a.x;
1603-
const bp = &b.x;
1604-
const cp = &c.x;
1605-
1606-
comptime assert(@TypeOf(ap) == *u32);
1607-
comptime assert(@TypeOf(bp) == *align(1) u32);
1608-
comptime assert(@TypeOf(cp) == *align(64) u32);
1609-
1610-
try expectEqual(@as(u32, 123), ap.*);
1611-
try expectEqual(@as(u32, 456), bp.*);
1612-
try expectEqual(@as(u32, 789), cp.*);
1613-
}
1614-
};
1615-
1616-
const U1 = extern union { x: u32 };
1617-
const U2 = packed union { x: u32 };
1618-
1619-
try S.doTheTest(U1);
1620-
try S.doTheTest(U2);
1621-
try comptime S.doTheTest(U1);
1622-
try comptime S.doTheTest(U2);
1623-
}
1624-
1625-
test "undefined-layout union field pointer has correct alignment" {
1626-
if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
1627-
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
1628-
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
1629-
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
1630-
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
1631-
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
1632-
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest; // TODO
1633-
1634-
const S = struct {
1635-
fn doTheTest(comptime U: type) !void {
1636-
var a: U = .{ .x = 123 };
1637-
var b: U align(1) = .{ .x = 456 };
1638-
var c: U align(64) = .{ .x = 789 };
1639-
1640-
const ap = &a.x;
1641-
const bp = &b.x;
1642-
const cp = &c.x;
1643-
1644-
comptime assert(@TypeOf(ap) == *u32);
1645-
comptime assert(@TypeOf(bp) == *align(1) u32);
1646-
comptime assert(@TypeOf(cp) == *u32); // undefined layout so does not inherit larger aligns
1647-
1648-
try expectEqual(@as(u32, 123), ap.*);
1649-
try expectEqual(@as(u32, 456), bp.*);
1650-
try expectEqual(@as(u32, 789), cp.*);
1651-
}
1652-
};
1653-
1654-
const U1 = union { x: u32 };
1655-
const U2 = union(enum) { x: u32 };
1656-
1657-
try S.doTheTest(U1);
1658-
try S.doTheTest(U2);
1659-
try comptime S.doTheTest(U1);
1660-
try comptime S.doTheTest(U2);
1661-
}
1662-
1663-
test "packed union field pointer has correct alignment" {
1664-
if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
1665-
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
1666-
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
1667-
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
1668-
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
1669-
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
1670-
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest; // TODO
1671-
1672-
const U = packed union { x: u20 };
1673-
const S = packed struct(u24) { a: u2, u: U, b: u2 };
1674-
1675-
var a: S = undefined;
1676-
var b: S align(1) = undefined;
1677-
var c: S align(64) = undefined;
1678-
1679-
const ap = &a.u.x;
1680-
const bp = &b.u.x;
1681-
const cp = &c.u.x;
1682-
1683-
comptime assert(@TypeOf(ap) == *align(4:2:3) u20);
1684-
comptime assert(@TypeOf(bp) == *align(1:2:3) u20);
1685-
comptime assert(@TypeOf(cp) == *align(64:2:3) u20);
1686-
1687-
a.u = .{ .x = 123 };
1688-
b.u = .{ .x = 456 };
1689-
c.u = .{ .x = 789 };
1690-
1691-
try expectEqual(@as(u20, 123), ap.*);
1692-
try expectEqual(@as(u20, 456), bp.*);
1693-
try expectEqual(@as(u20, 789), cp.*);
1694-
}

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