| author |  Andrew Kelley <andrew@ziglang.org> 2023-09-20 16:44:10-07:00 |
| committer | Andrew Kelley <andrew@ziglang.org> 2023-09-21 14:48:40-07:00 |
| log | 5ea3de55c4ca89b1f9fd95e40e6dd17cc89efe23 |
| tree | ec6fe5bed28ae7e691cee88f32c93402fc7124cd |
| parent | 2671aa9058b3dcff147ef01dcf3876b0bb231673 |
Sema: fix dependency loop regression on struct field alignment
2 files changed, 57 insertions(+), 18 deletions(-)
src/Sema.zig+49-2
| ... | @@ -34280,9 +34280,54 @@ pub fn resolveTypeLayout(sema: *Sema, ty: Type) CompileError!void { | ... | @@ -34280,9 +34280,54 @@ pub fn resolveTypeLayout(sema: *Sema, ty: Type) CompileError!void { |
| 34280 | } | 34280 | } |
| 34281 | } | 34281 | } |
| 34282 | 34282 | ||
| 34283 | fn resolveStructLayout(sema: *Sema, ty: Type) CompileError!void { | 34283 | /// Resolve a struct's alignment only without triggering resolution of its layout. |
| 34284 | try sema.resolveTypeFields(ty); | 34284 | /// Asserts that the alignment is not yet resolved and the layout is non-packed. |
| 34285 | pub fn resolveStructAlignment( | ||
| 34286 | sema: *Sema, | ||
| 34287 | ty: InternPool.Index, | ||
| 34288 | struct_type: InternPool.Key.StructType, | ||
| 34289 | ) CompileError!Alignment { | ||
| 34290 | const mod = sema.mod; | ||
| 34291 | const ip = &mod.intern_pool; | ||
| 34292 | const target = mod.getTarget(); | ||
| 34293 | |||
| 34294 | assert(struct_type.flagsPtr(ip).alignment == .none); | ||
| 34295 | assert(struct_type.layout != .Packed); | ||
| 34296 | |||
| 34297 | if (struct_type.flagsPtr(ip).field_types_wip) { | ||
| 34298 | // We'll guess "pointer-aligned", if the struct has an | ||
| 34299 | // underaligned pointer field then some allocations | ||
| 34300 | // might require explicit alignment. | ||
| 34301 | //TODO write this bit and emit an error later if incorrect | ||
| 34302 | //struct_type.flagsPtr(ip).assumed_pointer_aligned = true; | ||
| 34303 | const result = Alignment.fromByteUnits(@divExact(target.ptrBitWidth(), 8)); | ||
| 34304 | struct_type.flagsPtr(ip).alignment = result; | ||
| 34305 | return result; | ||
| 34306 | } | ||
| 34307 | |||
| 34308 | try sema.resolveTypeFieldsStruct(ty, struct_type); | ||
| 34309 | |||
| 34310 | var result: Alignment = .@"1"; | ||
| 34285 | 34311 | ||
| 34312 | for (0..struct_type.field_types.len) |i| { | ||
| 34313 | if (struct_type.fieldIsComptime(ip, i)) continue; | ||
| 34314 | const field_ty = struct_type.field_types.get(ip)[i].toType(); | ||
| 34315 | if (try sema.typeRequiresComptime(field_ty)) continue; | ||
| 34316 | if (try sema.typeHasRuntimeBits(field_ty)) { | ||
| 34317 | const field_align = try sema.structFieldAlignment( | ||
| 34318 | struct_type.fieldAlign(ip, i), | ||
| 34319 | field_ty, | ||
| 34320 | struct_type.layout, | ||
| 34321 | ); | ||
| 34322 | result = result.max(field_align); | ||
| 34323 | } | ||
| 34324 | } | ||
| 34325 | |||
| 34326 | struct_type.flagsPtr(ip).alignment = result; | ||
| 34327 | return result; | ||
| 34328 | } | ||
| 34329 | |||
| 34330 | fn resolveStructLayout(sema: *Sema, ty: Type) CompileError!void { | ||
| 34286 | const mod = sema.mod; | 34331 | const mod = sema.mod; |
| 34287 | const ip = &mod.intern_pool; | 34332 | const ip = &mod.intern_pool; |
| 34288 | const struct_type = mod.typeToStruct(ty) orelse return; | 34333 | const struct_type = mod.typeToStruct(ty) orelse return; |
| ... | @@ -34290,6 +34335,8 @@ fn resolveStructLayout(sema: *Sema, ty: Type) CompileError!void { | ... | @@ -34290,6 +34335,8 @@ fn resolveStructLayout(sema: *Sema, ty: Type) CompileError!void { |
| 34290 | if (struct_type.haveLayout(ip)) | 34335 | if (struct_type.haveLayout(ip)) |
| 34291 | return; | 34336 | return; |
| 34292 | 34337 | ||
| 34338 | try sema.resolveTypeFields(ty); | ||
| 34339 | |||
| 34293 | if (struct_type.layout == .Packed) { | 34340 | if (struct_type.layout == .Packed) { |
| 34294 | try semaBackingIntType(mod, struct_type); | 34341 | try semaBackingIntType(mod, struct_type); |
| 34295 | return; | 34342 | return; |
src/type.zig+8-16
| ... | @@ -201,7 +201,7 @@ pub const Type = struct { | ... | @@ -201,7 +201,7 @@ pub const Type = struct { |
| 201 | info.flags.alignment | 201 | info.flags.alignment |
| 202 | else | 202 | else |
| 203 | info.child.toType().abiAlignment(mod); | 203 | info.child.toType().abiAlignment(mod); |
| 204 | try writer.print("align({d}", .{alignment}); | 204 | try writer.print("align({d}", .{alignment.toByteUnits(0)}); |
| 205 | 205 | ||
| 206 | if (info.packed_offset.bit_offset != 0 or info.packed_offset.host_size != 0) { | 206 | if (info.packed_offset.bit_offset != 0 or info.packed_offset.host_size != 0) { |
| 207 | try writer.print(":{d}:{d}", .{ | 207 | try writer.print(":{d}:{d}", .{ |
| ... | @@ -992,30 +992,22 @@ pub const Type = struct { | ... | @@ -992,30 +992,22 @@ pub const Type = struct { |
| 992 | }, | 992 | }, |
| 993 | .eager => {}, | 993 | .eager => {}, |
| 994 | } | 994 | } |
| 995 | assert(struct_type.backingIntType(ip).* != .none); | ||
| 996 | return .{ .scalar = struct_type.backingIntType(ip).toType().abiAlignment(mod) }; | 995 | return .{ .scalar = struct_type.backingIntType(ip).toType().abiAlignment(mod) }; |
| 997 | } | 996 | } |
| 998 | 997 | ||
| 999 | const flags = struct_type.flagsPtr(ip).*; | 998 | const flags = struct_type.flagsPtr(ip).*; |
| 1000 | if (flags.layout_resolved) return .{ .scalar = flags.alignment }; | 999 | if (flags.alignment != .none) return .{ .scalar = flags.alignment }; |
| 1001 | 1000 | ||
| 1002 | switch (strat) { | 1001 | return switch (strat) { |
| 1003 | .eager => unreachable, // struct layout not resolved | 1002 | .eager => unreachable, // struct alignment not resolved |
| 1004 | .sema => |sema| { | 1003 | .sema => |sema| .{ |
| 1005 | if (flags.field_types_wip) { | 1004 | .scalar = try sema.resolveStructAlignment(ty.toIntern(), struct_type), |
| 1006 | // We'll guess "pointer-aligned", if the struct has an | ||
| 1007 | // underaligned pointer field then some allocations | ||
| 1008 | // might require explicit alignment. | ||
| 1009 | return .{ .scalar = Alignment.fromByteUnits(@divExact(target.ptrBitWidth(), 8)) }; | ||
| 1010 | } | ||
| 1011 | try sema.resolveTypeLayout(ty); | ||
| 1012 | return .{ .scalar = struct_type.flagsPtr(ip).alignment }; | ||
| 1013 | }, | 1005 | }, |
| 1014 | .lazy => return .{ .val = (try mod.intern(.{ .int = .{ | 1006 | .lazy => .{ .val = (try mod.intern(.{ .int = .{ |
| 1015 | .ty = .comptime_int_type, | 1007 | .ty = .comptime_int_type, |
| 1016 | .storage = .{ .lazy_align = ty.toIntern() }, | 1008 | .storage = .{ .lazy_align = ty.toIntern() }, |
| 1017 | } })).toValue() }, | 1009 | } })).toValue() }, |
| 1018 | } | 1010 | }; |
| 1019 | }, | 1011 | }, |
| 1020 | .anon_struct_type => |tuple| { | 1012 | .anon_struct_type => |tuple| { |
| 1021 | var big_align: Alignment = .none; | 1013 | var big_align: Alignment = .none; |