Commit 913d61ebb9

Andrew Kelley <andrew@ziglang.org>
2022-01-25 05:28:12
Revert "MultiArrayList: Fix error when struct is 0 sized"
This reverts commit 1f10cf4edf2b645e63dedc42f5d7475914bf2311. Re-opens #10618 I want to solve this a different way. `align(S)` where S is a 0-byte type should work in this context. This also caused issues such as https://github.com/Vexu/arocc/issues/221
1 parent 2e9ce6f
lib/std/array_hash_map.zig
@@ -2215,35 +2215,6 @@ test "auto store_hash" {
     try testing.expect(meta.fieldInfo(HasExpensiveEqlUn.Data, .hash).field_type != void);
 }
 
-test "0 sized key" {
-    var map = AutoArrayHashMap(u0, i32).init(std.testing.allocator);
-    defer map.deinit();
-
-    try testing.expectEqual(map.get(0), null);
-
-    try map.put(0, 5);
-    try testing.expectEqual(map.get(0), 5);
-
-    try map.put(0, 10);
-    try testing.expectEqual(map.get(0), 10);
-
-    try testing.expectEqual(map.swapRemove(0), true);
-    try testing.expectEqual(map.get(0), null);
-}
-
-test "0 sized key and 0 sized value" {
-    var map = AutoArrayHashMap(u0, u0).init(std.testing.allocator);
-    defer map.deinit();
-
-    try testing.expectEqual(map.get(0), null);
-
-    try map.put(0, 0);
-    try testing.expectEqual(map.get(0), 0);
-
-    try testing.expectEqual(map.swapRemove(0), true);
-    try testing.expectEqual(map.get(0), null);
-}
-
 pub fn getHashPtrAddrFn(comptime K: type, comptime Context: type) (fn (Context, K) u32) {
     return struct {
         fn hash(ctx: Context, key: K) u32 {
lib/std/multi_array_list.zig
@@ -16,9 +16,7 @@ const testing = std.testing;
 /// `.items(.<field_name>)` to obtain a slice of field values.
 pub fn MultiArrayList(comptime S: type) type {
     return struct {
-        const alignS = if (@alignOf(S) == 0) 1 else @alignOf(S);
-
-        bytes: [*]align(alignS) u8 = undefined,
+        bytes: [*]align(@alignOf(S)) u8 = undefined,
         len: usize = 0,
         capacity: usize = 0,
 
@@ -52,8 +50,8 @@ pub fn MultiArrayList(comptime S: type) type {
                     return .{};
                 }
                 const unaligned_ptr = self.ptrs[sizes.fields[0]];
-                const aligned_ptr = @alignCast(alignS, unaligned_ptr);
-                const casted_ptr = @ptrCast([*]align(alignS) u8, aligned_ptr);
+                const aligned_ptr = @alignCast(@alignOf(S), unaligned_ptr);
+                const casted_ptr = @ptrCast([*]align(@alignOf(S)) u8, aligned_ptr);
                 return .{
                     .bytes = casted_ptr,
                     .len = self.len,
@@ -263,7 +261,7 @@ pub fn MultiArrayList(comptime S: type) type {
 
             const other_bytes = gpa.allocAdvanced(
                 u8,
-                alignS,
+                @alignOf(S),
                 capacityInBytes(new_len),
                 .exact,
             ) catch {
@@ -341,7 +339,7 @@ pub fn MultiArrayList(comptime S: type) type {
             assert(new_capacity >= self.len);
             const new_bytes = try gpa.allocAdvanced(
                 u8,
-                alignS,
+                @alignOf(S),
                 capacityInBytes(new_capacity),
                 .exact,
             );
@@ -400,7 +398,7 @@ pub fn MultiArrayList(comptime S: type) type {
             return @reduce(.Add, capacity_vector * sizes_vector);
         }
 
-        fn allocatedBytes(self: Self) []align(alignS) u8 {
+        fn allocatedBytes(self: Self) []align(@alignOf(S)) u8 {
             return self.bytes[0..capacityInBytes(self.capacity)];
         }
 
@@ -623,52 +621,3 @@ test "insert elements" {
     try testing.expectEqualSlices(u8, &[_]u8{ 1, 2 }, list.items(.a));
     try testing.expectEqualSlices(u32, &[_]u32{ 2, 3 }, list.items(.b));
 }
-
-test "0 sized struct field" {
-    const ally = testing.allocator;
-
-    const Foo = struct {
-        a: u0,
-        b: f32,
-    };
-
-    var list = MultiArrayList(Foo){};
-    defer list.deinit(ally);
-
-    try testing.expectEqualSlices(u0, &[_]u0{}, list.items(.a));
-    try testing.expectEqualSlices(f32, &[_]f32{}, list.items(.b));
-
-    try list.append(ally, .{ .a = 0, .b = 42.0 });
-    try testing.expectEqualSlices(u0, &[_]u0{0}, list.items(.a));
-    try testing.expectEqualSlices(f32, &[_]f32{42.0}, list.items(.b));
-
-    try list.insert(ally, 0, .{ .a = 0, .b = -1.0 });
-    try testing.expectEqualSlices(u0, &[_]u0{ 0, 0 }, list.items(.a));
-    try testing.expectEqualSlices(f32, &[_]f32{ -1.0, 42.0 }, list.items(.b));
-
-    list.swapRemove(list.len - 1);
-    try testing.expectEqualSlices(u0, &[_]u0{0}, list.items(.a));
-    try testing.expectEqualSlices(f32, &[_]f32{-1.0}, list.items(.b));
-}
-
-test "0 sized struct" {
-    const ally = testing.allocator;
-
-    const Foo = struct {
-        a: u0,
-    };
-
-    var list = MultiArrayList(Foo){};
-    defer list.deinit(ally);
-
-    try testing.expectEqualSlices(u0, &[_]u0{}, list.items(.a));
-
-    try list.append(ally, .{ .a = 0 });
-    try testing.expectEqualSlices(u0, &[_]u0{0}, list.items(.a));
-
-    try list.insert(ally, 0, .{ .a = 0 });
-    try testing.expectEqualSlices(u0, &[_]u0{ 0, 0 }, list.items(.a));
-
-    list.swapRemove(list.len - 1);
-    try testing.expectEqualSlices(u0, &[_]u0{0}, list.items(.a));
-}