zig/src/TypedValue.zig
Andrew Kelley c0b5512544 compiler: start handling anonymous decls differently
Instead of explicitly creating a `Module.Decl` object for each anonymous
declaration, each `InternPool.Index` value is implicitly understood to
be an anonymous declaration when encountered by backend codegen.

The memory management strategy for these anonymous decls then becomes to
garbage collect them along with standard InternPool garbage.

In the interest of a smooth transition, this commit only implements this
new scheme for string literals and leaves all the previous mechanisms in
place.
2023-10-03 12:12:50 -07:00

523 lines
22 KiB
Zig

const std = @import("std");
const Type = @import("type.zig").Type;
const Value = @import("value.zig").Value;
const Module = @import("Module.zig");
const Allocator = std.mem.Allocator;
const TypedValue = @This();
const Target = std.Target;
ty: Type,
val: Value,
/// Memory management for TypedValue. The main purpose of this type
/// is to be small and have a deinit() function to free associated resources.
pub const Managed = struct {
/// If the tag value is less than Tag.no_payload_count, then no pointer
/// dereference is needed.
typed_value: TypedValue,
/// If this is `null` then there is no memory management needed.
arena: ?*std.heap.ArenaAllocator.State = null,
pub fn deinit(self: *Managed, allocator: Allocator) void {
if (self.arena) |a| a.promote(allocator).deinit();
self.* = undefined;
}
};
/// Assumes arena allocation. Does a recursive copy.
pub fn copy(self: TypedValue, arena: Allocator) error{OutOfMemory}!TypedValue {
return TypedValue{
.ty = self.ty,
.val = try self.val.copy(arena),
};
}
pub fn eql(a: TypedValue, b: TypedValue, mod: *Module) bool {
if (a.ty.toIntern() != b.ty.toIntern()) return false;
return a.val.eql(b.val, a.ty, mod);
}
pub fn hash(tv: TypedValue, hasher: *std.hash.Wyhash, mod: *Module) void {
return tv.val.hash(tv.ty, hasher, mod);
}
pub fn intFromEnum(tv: TypedValue, mod: *Module) Allocator.Error!Value {
return tv.val.intFromEnum(tv.ty, mod);
}
const max_aggregate_items = 100;
const max_string_len = 256;
const FormatContext = struct {
tv: TypedValue,
mod: *Module,
};
pub fn format(
ctx: FormatContext,
comptime fmt: []const u8,
options: std.fmt.FormatOptions,
writer: anytype,
) !void {
_ = options;
comptime std.debug.assert(fmt.len == 0);
return ctx.tv.print(writer, 3, ctx.mod) catch |err| switch (err) {
error.OutOfMemory => @panic("OOM"), // We're not allowed to return this from a format function
else => |e| return e,
};
}
/// Prints the Value according to the Type, not according to the Value Tag.
pub fn print(
tv: TypedValue,
writer: anytype,
level: u8,
mod: *Module,
) (@TypeOf(writer).Error || Allocator.Error)!void {
var val = tv.val;
var ty = tv.ty;
const ip = &mod.intern_pool;
while (true) switch (val.ip_index) {
.none => switch (val.tag()) {
.aggregate => return printAggregate(ty, val, writer, level, mod),
.@"union" => {
if (level == 0) {
return writer.writeAll(".{ ... }");
}
const payload = val.castTag(.@"union").?.data;
try writer.writeAll(".{ ");
if (payload.tag) |tag| {
try print(.{
.ty = ip.indexToKey(ty.toIntern()).union_type.enum_tag_ty.toType(),
.val = tag,
}, writer, level - 1, mod);
try writer.writeAll(" = ");
const field_ty = ty.unionFieldType(tag, mod).?;
try print(.{
.ty = field_ty,
.val = payload.val,
}, writer, level - 1, mod);
} else {
try writer.writeAll("(unknown tag) = ");
const backing_ty = try ty.unionBackingType(mod);
try print(.{
.ty = backing_ty,
.val = payload.val,
}, writer, level - 1, mod);
}
return writer.writeAll(" }");
},
.bytes => return writer.print("\"{}\"", .{std.zig.fmtEscapes(val.castTag(.bytes).?.data)}),
.repeated => {
if (level == 0) {
return writer.writeAll(".{ ... }");
}
var i: u32 = 0;
try writer.writeAll(".{ ");
const elem_tv = TypedValue{
.ty = ty.elemType2(mod),
.val = val.castTag(.repeated).?.data,
};
const len = ty.arrayLen(mod);
const max_len = @min(len, max_aggregate_items);
while (i < max_len) : (i += 1) {
if (i != 0) try writer.writeAll(", ");
try print(elem_tv, writer, level - 1, mod);
}
if (len > max_aggregate_items) {
try writer.writeAll(", ...");
}
return writer.writeAll(" }");
},
.slice => {
if (level == 0) {
return writer.writeAll(".{ ... }");
}
const payload = val.castTag(.slice).?.data;
const elem_ty = ty.elemType2(mod);
const len = payload.len.toUnsignedInt(mod);
if (elem_ty.eql(Type.u8, mod)) str: {
const max_len: usize = @min(len, max_string_len);
var buf: [max_string_len]u8 = undefined;
var i: u32 = 0;
while (i < max_len) : (i += 1) {
const maybe_elem_val = payload.ptr.maybeElemValue(mod, i) catch |err| switch (err) {
error.OutOfMemory => @panic("OOM"), // TODO: eliminate this panic
};
const elem_val = maybe_elem_val orelse return writer.writeAll(".{ (reinterpreted data) }");
if (elem_val.isUndef(mod)) break :str;
buf[i] = std.math.cast(u8, elem_val.toUnsignedInt(mod)) orelse break :str;
}
// TODO would be nice if this had a bit of unicode awareness.
const truncated = if (len > max_string_len) " (truncated)" else "";
return writer.print("\"{}{s}\"", .{ std.zig.fmtEscapes(buf[0..max_len]), truncated });
}
try writer.writeAll(".{ ");
const max_len = @min(len, max_aggregate_items);
var i: u32 = 0;
while (i < max_len) : (i += 1) {
if (i != 0) try writer.writeAll(", ");
const maybe_elem_val = payload.ptr.maybeElemValue(mod, i) catch |err| switch (err) {
error.OutOfMemory => @panic("OOM"), // TODO: eliminate this panic
};
const elem_val = maybe_elem_val orelse return writer.writeAll("(reinterpreted data) }");
try print(.{
.ty = elem_ty,
.val = elem_val,
}, writer, level - 1, mod);
}
if (len > max_aggregate_items) {
try writer.writeAll(", ...");
}
return writer.writeAll(" }");
},
.eu_payload => {
val = val.castTag(.eu_payload).?.data;
ty = ty.errorUnionPayload(mod);
},
.opt_payload => {
val = val.castTag(.opt_payload).?.data;
ty = ty.optionalChild(mod);
},
},
else => switch (ip.indexToKey(val.toIntern())) {
.int_type,
.ptr_type,
.array_type,
.vector_type,
.opt_type,
.anyframe_type,
.error_union_type,
.simple_type,
.struct_type,
.anon_struct_type,
.union_type,
.opaque_type,
.enum_type,
.func_type,
.error_set_type,
.inferred_error_set_type,
=> return Type.print(val.toType(), writer, mod),
.undef => return writer.writeAll("undefined"),
.runtime_value => return writer.writeAll("(runtime value)"),
.simple_value => |simple_value| switch (simple_value) {
.void => return writer.writeAll("{}"),
.empty_struct => return printAggregate(ty, val, writer, level, mod),
.generic_poison => return writer.writeAll("(generic poison)"),
else => return writer.writeAll(@tagName(simple_value)),
},
.variable => return writer.writeAll("(variable)"),
.extern_func => |extern_func| return writer.print("(extern function '{}')", .{
mod.declPtr(extern_func.decl).name.fmt(ip),
}),
.func => |func| return writer.print("(function '{}')", .{
mod.declPtr(func.owner_decl).name.fmt(ip),
}),
.int => |int| switch (int.storage) {
inline .u64, .i64, .big_int => |x| return writer.print("{}", .{x}),
.lazy_align => |lazy_ty| return writer.print("{d}", .{
lazy_ty.toType().abiAlignment(mod),
}),
.lazy_size => |lazy_ty| return writer.print("{d}", .{
lazy_ty.toType().abiSize(mod),
}),
},
.err => |err| return writer.print("error.{}", .{
err.name.fmt(ip),
}),
.error_union => |error_union| switch (error_union.val) {
.err_name => |err_name| return writer.print("error.{}", .{
err_name.fmt(ip),
}),
.payload => |payload| {
val = payload.toValue();
ty = ty.errorUnionPayload(mod);
},
},
.enum_literal => |enum_literal| return writer.print(".{}", .{
enum_literal.fmt(ip),
}),
.enum_tag => |enum_tag| {
if (level == 0) {
return writer.writeAll("(enum)");
}
const enum_type = ip.indexToKey(ty.toIntern()).enum_type;
if (enum_type.tagValueIndex(ip, val.toIntern())) |tag_index| {
try writer.print(".{i}", .{enum_type.names.get(ip)[tag_index].fmt(ip)});
return;
}
try writer.writeAll("@enumFromInt(");
try print(.{
.ty = ip.typeOf(enum_tag.int).toType(),
.val = enum_tag.int.toValue(),
}, writer, level - 1, mod);
try writer.writeAll(")");
return;
},
.empty_enum_value => return writer.writeAll("(empty enum value)"),
.float => |float| switch (float.storage) {
inline else => |x| return writer.print("{d}", .{@as(f64, @floatCast(x))}),
},
.ptr => |ptr| {
if (ptr.addr == .int) {
switch (ip.indexToKey(ptr.addr.int)) {
.int => |i| switch (i.storage) {
inline else => |addr| return writer.print("{x:0>8}", .{addr}),
},
.undef => return writer.writeAll("undefined"),
else => unreachable,
}
}
const ptr_ty = ip.indexToKey(ty.toIntern()).ptr_type;
if (ptr_ty.flags.size == .Slice) {
if (level == 0) {
return writer.writeAll(".{ ... }");
}
const elem_ty = ptr_ty.child.toType();
const len = ptr.len.toValue().toUnsignedInt(mod);
if (elem_ty.eql(Type.u8, mod)) str: {
const max_len = @min(len, max_string_len);
var buf: [max_string_len]u8 = undefined;
for (buf[0..max_len], 0..) |*c, i| {
const maybe_elem = try val.maybeElemValue(mod, i);
const elem = maybe_elem orelse return writer.writeAll(".{ (reinterpreted data) }");
if (elem.isUndef(mod)) break :str;
c.* = @as(u8, @intCast(elem.toUnsignedInt(mod)));
}
const truncated = if (len > max_string_len) " (truncated)" else "";
return writer.print("\"{}{s}\"", .{ std.zig.fmtEscapes(buf[0..max_len]), truncated });
}
try writer.writeAll(".{ ");
const max_len = @min(len, max_aggregate_items);
for (0..max_len) |i| {
if (i != 0) try writer.writeAll(", ");
const maybe_elem = try val.maybeElemValue(mod, i);
const elem = maybe_elem orelse return writer.writeAll("(reinterpreted data) }");
try print(.{
.ty = elem_ty,
.val = elem,
}, writer, level - 1, mod);
}
if (len > max_aggregate_items) {
try writer.writeAll(", ...");
}
return writer.writeAll(" }");
}
switch (ptr.addr) {
.decl => |decl_index| {
const decl = mod.declPtr(decl_index);
if (level == 0) return writer.print("(decl '{}')", .{decl.name.fmt(ip)});
return print(.{
.ty = decl.ty,
.val = decl.val,
}, writer, level - 1, mod);
},
.anon_decl => |decl_val| {
if (level == 0) return writer.print("(anon decl '{d}')", .{
@intFromEnum(decl_val),
});
return print(.{
.ty = ip.typeOf(decl_val).toType(),
.val = decl_val.toValue(),
}, writer, level - 1, mod);
},
.mut_decl => |mut_decl| {
const decl = mod.declPtr(mut_decl.decl);
if (level == 0) return writer.print("(mut decl '{}')", .{decl.name.fmt(ip)});
return print(.{
.ty = decl.ty,
.val = decl.val,
}, writer, level - 1, mod);
},
.comptime_field => |field_val_ip| {
return print(.{
.ty = ip.typeOf(field_val_ip).toType(),
.val = field_val_ip.toValue(),
}, writer, level - 1, mod);
},
.int => unreachable,
.eu_payload => |eu_ip| {
try writer.writeAll("(payload of ");
try print(.{
.ty = ip.typeOf(eu_ip).toType(),
.val = eu_ip.toValue(),
}, writer, level - 1, mod);
try writer.writeAll(")");
},
.opt_payload => |opt_ip| {
try print(.{
.ty = ip.typeOf(opt_ip).toType(),
.val = opt_ip.toValue(),
}, writer, level - 1, mod);
try writer.writeAll(".?");
},
.elem => |elem| {
try print(.{
.ty = ip.typeOf(elem.base).toType(),
.val = elem.base.toValue(),
}, writer, level - 1, mod);
try writer.print("[{}]", .{elem.index});
},
.field => |field| {
const ptr_container_ty = ip.typeOf(field.base).toType();
try print(.{
.ty = ptr_container_ty,
.val = field.base.toValue(),
}, writer, level - 1, mod);
const container_ty = ptr_container_ty.childType(mod);
switch (container_ty.zigTypeTag(mod)) {
.Struct => {
if (container_ty.structFieldName(@intCast(field.index), mod).unwrap()) |field_name| {
try writer.print(".{i}", .{field_name.fmt(ip)});
} else {
try writer.print("[{d}]", .{field.index});
}
},
.Union => {
const field_name = mod.typeToUnion(container_ty).?.field_names.get(ip)[@intCast(field.index)];
try writer.print(".{i}", .{field_name.fmt(ip)});
},
.Pointer => {
std.debug.assert(container_ty.isSlice(mod));
try writer.writeAll(switch (field.index) {
Value.slice_ptr_index => ".ptr",
Value.slice_len_index => ".len",
else => unreachable,
});
},
else => unreachable,
}
},
}
return;
},
.opt => |opt| switch (opt.val) {
.none => return writer.writeAll("null"),
else => |payload| {
val = payload.toValue();
ty = ty.optionalChild(mod);
},
},
.aggregate => |aggregate| switch (aggregate.storage) {
.bytes => |bytes| {
// Strip the 0 sentinel off of strings before printing
const zero_sent = blk: {
const sent = ty.sentinel(mod) orelse break :blk false;
break :blk sent.eql(Value.zero_u8, Type.u8, mod);
};
const str = if (zero_sent) bytes[0 .. bytes.len - 1] else bytes;
return writer.print("\"{}\"", .{std.zig.fmtEscapes(str)});
},
.elems, .repeated_elem => return printAggregate(ty, val, writer, level, mod),
},
.un => |un| {
try writer.writeAll(".{ ");
if (level > 0) {
if (un.tag != .none) {
try print(.{
.ty = ty.unionTagTypeHypothetical(mod),
.val = un.tag.toValue(),
}, writer, level - 1, mod);
try writer.writeAll(" = ");
const field_ty = ty.unionFieldType(un.tag.toValue(), mod).?;
try print(.{
.ty = field_ty,
.val = un.val.toValue(),
}, writer, level - 1, mod);
} else {
try writer.writeAll("(unknown tag) = ");
const backing_ty = try ty.unionBackingType(mod);
try print(.{
.ty = backing_ty,
.val = un.val.toValue(),
}, writer, level - 1, mod);
}
} else try writer.writeAll("...");
return writer.writeAll(" }");
},
.memoized_call => unreachable,
},
};
}
fn printAggregate(
ty: Type,
val: Value,
writer: anytype,
level: u8,
mod: *Module,
) (@TypeOf(writer).Error || Allocator.Error)!void {
if (level == 0) {
return writer.writeAll(".{ ... }");
}
const ip = &mod.intern_pool;
if (ty.zigTypeTag(mod) == .Struct) {
try writer.writeAll(".{");
const max_len = @min(ty.structFieldCount(mod), max_aggregate_items);
for (0..max_len) |i| {
if (i != 0) try writer.writeAll(", ");
const field_name = switch (ip.indexToKey(ty.toIntern())) {
.struct_type => |x| x.fieldName(ip, i),
.anon_struct_type => |x| if (x.isTuple()) .none else x.names.get(ip)[i].toOptional(),
else => unreachable,
};
if (field_name.unwrap()) |name| try writer.print(".{} = ", .{name.fmt(ip)});
try print(.{
.ty = ty.structFieldType(i, mod),
.val = try val.fieldValue(mod, i),
}, writer, level - 1, mod);
}
if (ty.structFieldCount(mod) > max_aggregate_items) {
try writer.writeAll(", ...");
}
return writer.writeAll("}");
} else {
const elem_ty = ty.elemType2(mod);
const len = ty.arrayLen(mod);
if (elem_ty.eql(Type.u8, mod)) str: {
const max_len: usize = @min(len, max_string_len);
var buf: [max_string_len]u8 = undefined;
var i: u32 = 0;
while (i < max_len) : (i += 1) {
const elem = try val.fieldValue(mod, i);
if (elem.isUndef(mod)) break :str;
buf[i] = std.math.cast(u8, elem.toUnsignedInt(mod)) orelse break :str;
}
const truncated = if (len > max_string_len) " (truncated)" else "";
return writer.print("\"{}{s}\"", .{ std.zig.fmtEscapes(buf[0..max_len]), truncated });
}
try writer.writeAll(".{ ");
const max_len = @min(len, max_aggregate_items);
var i: u32 = 0;
while (i < max_len) : (i += 1) {
if (i != 0) try writer.writeAll(", ");
try print(.{
.ty = elem_ty,
.val = try val.fieldValue(mod, i),
}, writer, level - 1, mod);
}
if (len > max_aggregate_items) {
try writer.writeAll(", ...");
}
return writer.writeAll(" }");
}
}