Commit 75eaf15740

Vexu <git@vexu.eu>
2020-08-12 15:00:29
stage2: add optional types
1 parent cb06d62
Changed files (1)
src-self-hosted
src-self-hosted/type.zig
@@ -70,6 +70,11 @@ pub const Type = extern union {
             .single_mut_pointer => return .Pointer,
             .single_const_pointer_to_comptime_int => return .Pointer,
             .const_slice_u8 => return .Pointer,
+
+            .optional,
+            .optional_single_const_pointer,
+            .optional_single_mut_pointer,
+            => return .Optional,
         }
     }
 
@@ -179,9 +184,13 @@ pub const Type = extern union {
                 }
                 return true;
             },
+            .Optional => {
+                if (a.tag() != b.tag())
+                    return false;
+                return a.elemType().eql(b.elemType());
+            },
             .Float,
             .Struct,
-            .Optional,
             .ErrorUnion,
             .ErrorSet,
             .Enum,
@@ -241,9 +250,11 @@ pub const Type = extern union {
                     std.hash.autoHash(&hasher, self.fnParamType(i).hash());
                 }
             },
+            .Optional => {
+                std.hash.autoHash(&hasher, self.elemType().hash());
+            },
             .Float,
             .Struct,
-            .Optional,
             .ErrorUnion,
             .ErrorSet,
             .Enum,
@@ -317,24 +328,8 @@ pub const Type = extern union {
                 };
                 return Type{ .ptr_otherwise = &new_payload.base };
             },
-            .single_const_pointer => {
-                const payload = @fieldParentPtr(Payload.SingleConstPointer, "base", self.ptr_otherwise);
-                const new_payload = try allocator.create(Payload.SingleConstPointer);
-                new_payload.* = .{
-                    .base = payload.base,
-                    .pointee_type = try payload.pointee_type.copy(allocator),
-                };
-                return Type{ .ptr_otherwise = &new_payload.base };
-            },
-            .single_mut_pointer => {
-                const payload = @fieldParentPtr(Payload.SingleMutPointer, "base", self.ptr_otherwise);
-                const new_payload = try allocator.create(Payload.SingleMutPointer);
-                new_payload.* = .{
-                    .base = payload.base,
-                    .pointee_type = try payload.pointee_type.copy(allocator),
-                };
-                return Type{ .ptr_otherwise = &new_payload.base };
-            },
+            .single_const_pointer => return self.copyPayloadSingleField(allocator, Payload.SingleConstPointer, "pointee_type"),
+            .single_mut_pointer => return self.copyPayloadSingleField(allocator, Payload.SingleMutPointer, "pointee_type"),
             .int_signed => return self.copyPayloadShallow(allocator, Payload.IntSigned),
             .int_unsigned => return self.copyPayloadShallow(allocator, Payload.IntUnsigned),
             .function => {
@@ -352,6 +347,9 @@ pub const Type = extern union {
                 };
                 return Type{ .ptr_otherwise = &new_payload.base };
             },
+            .optional => return self.copyPayloadSingleField(allocator, Payload.Optional, "child_type"),
+            .optional_single_mut_pointer => return self.copyPayloadSingleField(allocator, Payload.OptionalSingleMutPointer, "pointee_type"),
+            .optional_single_const_pointer => return self.copyPayloadSingleField(allocator, Payload.OptionalSingleConstPointer, "pointee_type"),
         }
     }
 
@@ -362,6 +360,14 @@ pub const Type = extern union {
         return Type{ .ptr_otherwise = &new_payload.base };
     }
 
+    fn copyPayloadSingleField(self: Type, allocator: *Allocator, comptime T: type, comptime field_name: []const u8) error{OutOfMemory}!Type {
+        const payload = @fieldParentPtr(T, "base", self.ptr_otherwise);
+        const new_payload = try allocator.create(T);
+        new_payload.base = payload.base;
+        @field(new_payload, field_name) = try @field(payload, field_name).copy(allocator);
+        return Type{ .ptr_otherwise = &new_payload.base };
+    }
+
     pub fn format(
         self: Type,
         comptime fmt: []const u8,
@@ -456,6 +462,24 @@ pub const Type = extern union {
                     const payload = @fieldParentPtr(Payload.IntUnsigned, "base", ty.ptr_otherwise);
                     return out_stream.print("u{}", .{payload.bits});
                 },
+                .optional => {
+                    const payload = @fieldParentPtr(Payload.Optional, "base", ty.ptr_otherwise);
+                    try out_stream.writeByte('?');
+                    ty = payload.child_type;
+                    continue;
+                },
+                .optional_single_const_pointer => {
+                    const payload = @fieldParentPtr(Payload.OptionalSingleConstPointer, "base", ty.ptr_otherwise);
+                    try out_stream.writeAll("?*const ");
+                    ty = payload.pointee_type;
+                    continue;
+                },
+                .optional_single_mut_pointer => {
+                    const payload = @fieldParentPtr(Payload.OptionalSingleMutPointer, "base", ty.ptr_otherwise);
+                    try out_stream.writeAll("?*");
+                    ty = payload.pointee_type;
+                    continue;
+                },
             }
             unreachable;
         }
@@ -545,11 +569,15 @@ pub const Type = extern union {
             .single_const_pointer_to_comptime_int,
             .const_slice_u8,
             .array_u8_sentinel_0,
-            .array, // TODO check for zero bits
-            .single_const_pointer,
-            .single_mut_pointer,
-            .int_signed, // TODO check for zero bits
-            .int_unsigned, // TODO check for zero bits
+            // TODO lazy types
+            .array => self.elemType().hasCodeGenBits() and self.arrayLen() != 0,
+            .single_const_pointer => self.elemType().hasCodeGenBits(),
+            .single_mut_pointer => self.elemType().hasCodeGenBits(),
+            .int_signed => self.cast(Payload.IntSigned).?.bits == 0,
+            .int_unsigned => self.cast(Payload.IntUnsigned).?.bits == 0,
+            .optional,
+            .optional_single_mut_pointer,
+            .optional_single_const_pointer,
             => true,
 
             .c_void,
@@ -597,6 +625,8 @@ pub const Type = extern union {
             .const_slice_u8,
             .single_const_pointer,
             .single_mut_pointer,
+            .optional_single_const_pointer,
+            .optional_single_mut_pointer,
             => return @divExact(target.cpu.arch.ptrBitWidth(), 8),
 
             .c_short => return @divExact(CType.short.sizeInBits(target), 8),
@@ -629,6 +659,12 @@ pub const Type = extern union {
                 return std.math.ceilPowerOfTwoPromote(u16, (bits + 7) / 8);
             },
 
+            .optional => {
+                const child_type = self.cast(Payload.Optional).?.child_type;
+                if (!child_type.hasCodeGenBits()) return 1;
+                return child_type.abiAlignment(target);
+            },
+
             .c_void,
             .void,
             .type,
@@ -679,6 +715,8 @@ pub const Type = extern union {
             .const_slice_u8,
             .single_const_pointer,
             .single_mut_pointer,
+            .optional_single_const_pointer,
+            .optional_single_mut_pointer,
             => return @divExact(target.cpu.arch.ptrBitWidth(), 8),
 
             .c_short => return @divExact(CType.short.sizeInBits(target), 8),
@@ -708,6 +746,16 @@ pub const Type = extern union {
 
                 return std.math.ceilPowerOfTwoPromote(u16, (bits + 7) / 8);
             },
+
+            .optional => {
+                const child_type = self.cast(Payload.Optional).?.child_type;
+                if (!child_type.hasCodeGenBits()) return 1;
+                // Optional types are represented as a struct with the child type as the first
+                // field and a boolean as the second. Since the child type's abi alignment is
+                // guaranteed to be >= that of bool's (1 byte) the added size is exactly equal
+                // to the child type's ABI alignment.
+                return child_type.abiAlignment(target) + child_type.abiSize(target);
+            },
         };
     }
 
@@ -756,6 +804,9 @@ pub const Type = extern union {
             .function,
             .int_unsigned,
             .int_signed,
+            .optional,
+            .optional_single_mut_pointer,
+            .optional_single_const_pointer,
             => false,
 
             .single_const_pointer,
@@ -812,6 +863,9 @@ pub const Type = extern union {
             .function,
             .int_unsigned,
             .int_signed,
+            .optional,
+            .optional_single_mut_pointer,
+            .optional_single_const_pointer,
             => false,
 
             .const_slice_u8 => true,
@@ -863,6 +917,9 @@ pub const Type = extern union {
             .int_unsigned,
             .int_signed,
             .single_mut_pointer,
+            .optional,
+            .optional_single_mut_pointer,
+            .optional_single_const_pointer,
             => false,
 
             .single_const_pointer,
@@ -920,11 +977,14 @@ pub const Type = extern union {
             .single_const_pointer,
             .single_const_pointer_to_comptime_int,
             .const_slice_u8,
+            .optional,
+            .optional_single_mut_pointer,
+            .optional_single_const_pointer,
             => false,
         };
     }
 
-    /// Asserts the type is a pointer or array type.
+    /// Asserts the type is a pointer, optional or array type.
     pub fn elemType(self: Type) Type {
         return switch (self.tag()) {
             .u8,
@@ -974,6 +1034,9 @@ pub const Type = extern union {
             .single_mut_pointer => self.cast(Payload.SingleMutPointer).?.pointee_type,
             .array_u8_sentinel_0, .const_slice_u8 => Type.initTag(.u8),
             .single_const_pointer_to_comptime_int => Type.initTag(.comptime_int),
+            .optional => self.cast(Payload.Optional).?.child_type,
+            .optional_single_mut_pointer => self.cast(Payload.OptionalSingleMutPointer).?.pointee_type,
+            .optional_single_const_pointer => self.cast(Payload.OptionalSingleConstPointer).?.pointee_type,
         };
     }
 
@@ -1024,6 +1087,9 @@ pub const Type = extern union {
             .const_slice_u8,
             .int_unsigned,
             .int_signed,
+            .optional,
+            .optional_single_mut_pointer,
+            .optional_single_const_pointer,
             => unreachable,
 
             .array => self.cast(Payload.Array).?.len,
@@ -1078,6 +1144,9 @@ pub const Type = extern union {
             .const_slice_u8,
             .int_unsigned,
             .int_signed,
+            .optional,
+            .optional_single_mut_pointer,
+            .optional_single_const_pointer,
             => unreachable,
 
             .array => return null,
@@ -1129,6 +1198,9 @@ pub const Type = extern union {
             .u16,
             .u32,
             .u64,
+            .optional,
+            .optional_single_mut_pointer,
+            .optional_single_const_pointer,
             => false,
 
             .int_signed,
@@ -1184,6 +1256,9 @@ pub const Type = extern union {
             .i16,
             .i32,
             .i64,
+            .optional,
+            .optional_single_mut_pointer,
+            .optional_single_const_pointer,
             => false,
 
             .int_unsigned,
@@ -1229,6 +1304,9 @@ pub const Type = extern union {
             .single_const_pointer_to_comptime_int,
             .array_u8_sentinel_0,
             .const_slice_u8,
+            .optional,
+            .optional_single_mut_pointer,
+            .optional_single_const_pointer,
             => unreachable,
 
             .int_unsigned => .{ .signed = false, .bits = self.cast(Payload.IntUnsigned).?.bits },
@@ -1292,6 +1370,9 @@ pub const Type = extern union {
             .i32,
             .u64,
             .i64,
+            .optional,
+            .optional_single_mut_pointer,
+            .optional_single_const_pointer,
             => false,
 
             .usize,
@@ -1384,6 +1465,9 @@ pub const Type = extern union {
             .c_ulonglong,
             .int_unsigned,
             .int_signed,
+            .optional,
+            .optional_single_mut_pointer,
+            .optional_single_const_pointer,
             => unreachable,
         };
     }
@@ -1442,6 +1526,9 @@ pub const Type = extern union {
             .c_ulonglong,
             .int_unsigned,
             .int_signed,
+            .optional,
+            .optional_single_mut_pointer,
+            .optional_single_const_pointer,
             => unreachable,
         }
     }
@@ -1499,6 +1586,9 @@ pub const Type = extern union {
             .c_ulonglong,
             .int_unsigned,
             .int_signed,
+            .optional,
+            .optional_single_mut_pointer,
+            .optional_single_const_pointer,
             => unreachable,
         }
     }
@@ -1556,6 +1646,9 @@ pub const Type = extern union {
             .c_ulonglong,
             .int_unsigned,
             .int_signed,
+            .optional,
+            .optional_single_mut_pointer,
+            .optional_single_const_pointer,
             => unreachable,
         };
     }
@@ -1610,6 +1703,9 @@ pub const Type = extern union {
             .c_ulonglong,
             .int_unsigned,
             .int_signed,
+            .optional,
+            .optional_single_mut_pointer,
+            .optional_single_const_pointer,
             => unreachable,
         };
     }
@@ -1664,6 +1760,9 @@ pub const Type = extern union {
             .c_ulonglong,
             .int_unsigned,
             .int_signed,
+            .optional,
+            .optional_single_mut_pointer,
+            .optional_single_const_pointer,
             => unreachable,
         };
     }
@@ -1718,6 +1817,9 @@ pub const Type = extern union {
             .single_const_pointer_to_comptime_int,
             .array_u8_sentinel_0,
             .const_slice_u8,
+            .optional,
+            .optional_single_mut_pointer,
+            .optional_single_const_pointer,
             => false,
         };
     }
@@ -1762,6 +1864,9 @@ pub const Type = extern union {
             .array_u8_sentinel_0,
             .const_slice_u8,
             .c_void,
+            .optional,
+            .optional_single_mut_pointer,
+            .optional_single_const_pointer,
             => return null,
 
             .void => return Value.initTag(.void_value),
@@ -1851,6 +1956,9 @@ pub const Type = extern union {
             .array,
             .single_const_pointer,
             .single_mut_pointer,
+            .optional,
+            .optional_single_mut_pointer,
+            .optional_single_const_pointer,
             => return false,
         };
     }
@@ -1911,6 +2019,9 @@ pub const Type = extern union {
         int_signed,
         int_unsigned,
         function,
+        optional,
+        optional_single_mut_pointer,
+        optional_single_const_pointer,
 
         pub const last_no_payload_tag = Tag.const_slice_u8;
         pub const no_payload_count = @enumToInt(last_no_payload_tag) + 1;
@@ -1963,6 +2074,24 @@ pub const Type = extern union {
             return_type: Type,
             cc: std.builtin.CallingConvention,
         };
+
+        pub const Optional = struct {
+            base: Payload = Payload{ .tag = .optional },
+
+            child_type: Type,
+        };
+
+        pub const OptionalSingleConstPointer = struct {
+            base: Payload = Payload{ .tag = .optional_single_const_pointer },
+
+            pointee_type: Type,
+        };
+
+        pub const OptionalSingleMutPointer = struct {
+            base: Payload = Payload{ .tag = .optional_single_mut_pointer },
+
+            pointee_type: Type,
+        };
     };
 };