zig/src/print_value.zig
Andrew Kelley 0fcd59eada rename src/Module.zig to src/Zcu.zig
This patch is a pure rename plus only changing the file path in
`@import` sites, so it is expected to not create version control
conflicts, even when rebasing.
2024-06-22 22:59:56 -04:00

367 lines
15 KiB
Zig

//! This type exists only for legacy purposes, and will be removed in the future.
//! It is a thin wrapper around a `Value` which also, redundantly, stores its `Type`.
const std = @import("std");
const Type = @import("type.zig").Type;
const Value = @import("Value.zig");
const Zcu = @import("Zcu.zig");
/// Deprecated.
const Module = Zcu;
const Sema = @import("Sema.zig");
const InternPool = @import("InternPool.zig");
const Allocator = std.mem.Allocator;
const Target = std.Target;
const max_aggregate_items = 100;
const max_string_len = 256;
pub const FormatContext = struct {
val: Value,
mod: *Module,
opt_sema: ?*Sema,
depth: u8,
};
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 print(ctx.val, writer, ctx.depth, ctx.mod, ctx.opt_sema) catch |err| switch (err) {
error.OutOfMemory => @panic("OOM"), // We're not allowed to return this from a format function
error.ComptimeBreak, error.ComptimeReturn => unreachable,
error.AnalysisFail => unreachable, // TODO: re-evaluate when we use `opt_sema` more fully
else => |e| return e,
};
}
pub fn print(
val: Value,
writer: anytype,
level: u8,
mod: *Module,
/// If this `Sema` is provided, we will recurse through pointers where possible to provide friendly output.
opt_sema: ?*Sema,
) (@TypeOf(writer).Error || Module.CompileError)!void {
const ip = &mod.intern_pool;
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,
=> try Type.print(val.toType(), writer, mod),
.undef => try writer.writeAll("undefined"),
.simple_value => |simple_value| switch (simple_value) {
.void => try writer.writeAll("{}"),
.empty_struct => try writer.writeAll(".{}"),
.generic_poison => try writer.writeAll("(generic poison)"),
else => try writer.writeAll(@tagName(simple_value)),
},
.variable => try writer.writeAll("(variable)"),
.extern_func => |extern_func| try writer.print("(extern function '{}')", .{
mod.declPtr(extern_func.decl).name.fmt(ip),
}),
.func => |func| try writer.print("(function '{}')", .{
mod.declPtr(func.owner_decl).name.fmt(ip),
}),
.int => |int| switch (int.storage) {
inline .u64, .i64, .big_int => |x| try writer.print("{}", .{x}),
.lazy_align => |ty| if (opt_sema) |sema| {
const a = (try Type.fromInterned(ty).abiAlignmentAdvanced(mod, .{ .sema = sema })).scalar;
try writer.print("{}", .{a.toByteUnits() orelse 0});
} else try writer.print("@alignOf({})", .{Type.fromInterned(ty).fmt(mod)}),
.lazy_size => |ty| if (opt_sema) |sema| {
const s = (try Type.fromInterned(ty).abiSizeAdvanced(mod, .{ .sema = sema })).scalar;
try writer.print("{}", .{s});
} else try writer.print("@sizeOf({})", .{Type.fromInterned(ty).fmt(mod)}),
},
.err => |err| try writer.print("error.{}", .{
err.name.fmt(ip),
}),
.error_union => |error_union| switch (error_union.val) {
.err_name => |err_name| try writer.print("error.{}", .{
err_name.fmt(ip),
}),
.payload => |payload| try print(Value.fromInterned(payload), writer, level, mod, opt_sema),
},
.enum_literal => |enum_literal| try writer.print(".{}", .{
enum_literal.fmt(ip),
}),
.enum_tag => |enum_tag| {
const enum_type = ip.loadEnumType(val.typeOf(mod).toIntern());
if (enum_type.tagValueIndex(ip, val.toIntern())) |tag_index| {
return writer.print(".{i}", .{enum_type.names.get(ip)[tag_index].fmt(ip)});
}
if (level == 0) {
return writer.writeAll("@enumFromInt(...)");
}
try writer.writeAll("@enumFromInt(");
try print(Value.fromInterned(enum_tag.int), writer, level - 1, mod, opt_sema);
try writer.writeAll(")");
},
.empty_enum_value => try writer.writeAll("(empty enum value)"),
.float => |float| switch (float.storage) {
inline else => |x| try writer.print("{d}", .{@as(f64, @floatCast(x))}),
},
.slice => |slice| {
const print_contents = switch (ip.getBackingAddrTag(slice.ptr).?) {
.field, .arr_elem, .eu_payload, .opt_payload => unreachable,
.anon_decl, .comptime_alloc, .comptime_field => true,
.decl, .int => false,
};
if (print_contents) {
// TODO: eventually we want to load the slice as an array with `opt_sema`, but that's
// currently not possible without e.g. triggering compile errors.
}
try printPtr(Value.fromInterned(slice.ptr), writer, level, mod, opt_sema);
try writer.writeAll("[0..");
if (level == 0) {
try writer.writeAll("(...)");
} else {
try print(Value.fromInterned(slice.len), writer, level - 1, mod, opt_sema);
}
try writer.writeAll("]");
},
.ptr => {
const print_contents = switch (ip.getBackingAddrTag(val.toIntern()).?) {
.field, .arr_elem, .eu_payload, .opt_payload => unreachable,
.anon_decl, .comptime_alloc, .comptime_field => true,
.decl, .int => false,
};
if (print_contents) {
// TODO: eventually we want to load the pointer with `opt_sema`, but that's
// currently not possible without e.g. triggering compile errors.
}
try printPtr(val, writer, level, mod, opt_sema);
},
.opt => |opt| switch (opt.val) {
.none => try writer.writeAll("null"),
else => |payload| try print(Value.fromInterned(payload), writer, level, mod, opt_sema),
},
.aggregate => |aggregate| try printAggregate(val, aggregate, false, writer, level, mod, opt_sema),
.un => |un| {
if (level == 0) {
try writer.writeAll(".{ ... }");
return;
}
if (un.tag == .none) {
const backing_ty = try val.typeOf(mod).unionBackingType(mod);
try writer.print("@bitCast(@as({}, ", .{backing_ty.fmt(mod)});
try print(Value.fromInterned(un.val), writer, level - 1, mod, opt_sema);
try writer.writeAll("))");
} else {
try writer.writeAll(".{ ");
try print(Value.fromInterned(un.tag), writer, level - 1, mod, opt_sema);
try writer.writeAll(" = ");
try print(Value.fromInterned(un.val), writer, level - 1, mod, opt_sema);
try writer.writeAll(" }");
}
},
.memoized_call => unreachable,
}
}
fn printAggregate(
val: Value,
aggregate: InternPool.Key.Aggregate,
is_ref: bool,
writer: anytype,
level: u8,
zcu: *Zcu,
opt_sema: ?*Sema,
) (@TypeOf(writer).Error || Module.CompileError)!void {
if (level == 0) {
if (is_ref) try writer.writeByte('&');
return writer.writeAll(".{ ... }");
}
const ip = &zcu.intern_pool;
const ty = Type.fromInterned(aggregate.ty);
switch (ty.zigTypeTag(zcu)) {
.Struct => if (!ty.isTuple(zcu)) {
if (is_ref) try writer.writeByte('&');
if (ty.structFieldCount(zcu) == 0) {
return writer.writeAll(".{}");
}
try writer.writeAll(".{ ");
const max_len = @min(ty.structFieldCount(zcu), max_aggregate_items);
for (0..max_len) |i| {
if (i != 0) try writer.writeAll(", ");
const field_name = ty.structFieldName(@intCast(i), zcu).unwrap().?;
try writer.print(".{i} = ", .{field_name.fmt(ip)});
try print(try val.fieldValue(zcu, i), writer, level - 1, zcu, opt_sema);
}
try writer.writeAll(" }");
return;
},
.Array => {
switch (aggregate.storage) {
.bytes => |bytes| string: {
const len = ty.arrayLenIncludingSentinel(zcu);
if (len == 0) break :string;
const slice = bytes.toSlice(if (bytes.at(len - 1, ip) == 0) len - 1 else len, ip);
try writer.print("\"{}\"", .{std.zig.fmtEscapes(slice)});
if (!is_ref) try writer.writeAll(".*");
return;
},
.elems, .repeated_elem => {},
}
switch (ty.arrayLen(zcu)) {
0 => {
if (is_ref) try writer.writeByte('&');
return writer.writeAll(".{}");
},
1 => one_byte_str: {
// The repr isn't `bytes`, but we might still be able to print this as a string
if (ty.childType(zcu).toIntern() != .u8_type) break :one_byte_str;
const elem_val = Value.fromInterned(aggregate.storage.values()[0]);
if (elem_val.isUndef(zcu)) break :one_byte_str;
const byte = elem_val.toUnsignedInt(zcu);
try writer.print("\"{}\"", .{std.zig.fmtEscapes(&.{@intCast(byte)})});
if (!is_ref) try writer.writeAll(".*");
return;
},
else => {},
}
},
.Vector => if (ty.arrayLen(zcu) == 0) {
if (is_ref) try writer.writeByte('&');
return writer.writeAll(".{}");
},
else => unreachable,
}
const len = ty.arrayLen(zcu);
if (is_ref) try writer.writeByte('&');
try writer.writeAll(".{ ");
const max_len = @min(len, max_aggregate_items);
for (0..max_len) |i| {
if (i != 0) try writer.writeAll(", ");
try print(try val.fieldValue(zcu, i), writer, level - 1, zcu, opt_sema);
}
if (len > max_aggregate_items) {
try writer.writeAll(", ...");
}
return writer.writeAll(" }");
}
fn printPtr(ptr_val: Value, writer: anytype, level: u8, zcu: *Zcu, opt_sema: ?*Sema) (@TypeOf(writer).Error || Module.CompileError)!void {
const ptr = switch (zcu.intern_pool.indexToKey(ptr_val.toIntern())) {
.undef => return writer.writeAll("undefined"),
.ptr => |ptr| ptr,
else => unreachable,
};
if (ptr.base_addr == .anon_decl) {
// If the value is an aggregate, we can potentially print it more nicely.
switch (zcu.intern_pool.indexToKey(ptr.base_addr.anon_decl.val)) {
.aggregate => |agg| return printAggregate(
Value.fromInterned(ptr.base_addr.anon_decl.val),
agg,
true,
writer,
level,
zcu,
opt_sema,
),
else => {},
}
}
var arena = std.heap.ArenaAllocator.init(zcu.gpa);
defer arena.deinit();
const derivation = try ptr_val.pointerDerivationAdvanced(arena.allocator(), zcu, opt_sema);
try printPtrDerivation(derivation, writer, level, zcu, opt_sema);
}
/// Print `derivation` as an lvalue, i.e. such that writing `&` before this gives the pointer value.
fn printPtrDerivation(derivation: Value.PointerDeriveStep, writer: anytype, level: u8, zcu: *Zcu, opt_sema: ?*Sema) (@TypeOf(writer).Error || Module.CompileError)!void {
const ip = &zcu.intern_pool;
switch (derivation) {
.int => |int| try writer.print("@as({}, @ptrFromInt({x})).*", .{
int.ptr_ty.fmt(zcu),
int.addr,
}),
.decl_ptr => |decl| {
try zcu.declPtr(decl).renderFullyQualifiedName(zcu, writer);
},
.anon_decl_ptr => |anon| {
const ty = Value.fromInterned(anon.val).typeOf(zcu);
try writer.print("@as({}, ", .{ty.fmt(zcu)});
try print(Value.fromInterned(anon.val), writer, level - 1, zcu, opt_sema);
try writer.writeByte(')');
},
.comptime_alloc_ptr => |info| {
try writer.print("@as({}, ", .{info.val.typeOf(zcu).fmt(zcu)});
try print(info.val, writer, level - 1, zcu, opt_sema);
try writer.writeByte(')');
},
.comptime_field_ptr => |val| {
const ty = val.typeOf(zcu);
try writer.print("@as({}, ", .{ty.fmt(zcu)});
try print(val, writer, level - 1, zcu, opt_sema);
try writer.writeByte(')');
},
.eu_payload_ptr => |info| {
try writer.writeByte('(');
try printPtrDerivation(info.parent.*, writer, level, zcu, opt_sema);
try writer.writeAll(" catch unreachable)");
},
.opt_payload_ptr => |info| {
try printPtrDerivation(info.parent.*, writer, level, zcu, opt_sema);
try writer.writeAll(".?");
},
.field_ptr => |field| {
try printPtrDerivation(field.parent.*, writer, level, zcu, opt_sema);
const agg_ty = (try field.parent.ptrType(zcu)).childType(zcu);
switch (agg_ty.zigTypeTag(zcu)) {
.Struct => if (agg_ty.structFieldName(field.field_idx, zcu).unwrap()) |field_name| {
try writer.print(".{i}", .{field_name.fmt(ip)});
} else {
try writer.print("[{d}]", .{field.field_idx});
},
.Union => {
const tag_ty = agg_ty.unionTagTypeHypothetical(zcu);
const field_name = tag_ty.enumFieldName(field.field_idx, zcu);
try writer.print(".{i}", .{field_name.fmt(ip)});
},
.Pointer => switch (field.field_idx) {
Value.slice_ptr_index => try writer.writeAll(".ptr"),
Value.slice_len_index => try writer.writeAll(".len"),
else => unreachable,
},
else => unreachable,
}
},
.elem_ptr => |elem| {
try printPtrDerivation(elem.parent.*, writer, level, zcu, opt_sema);
try writer.print("[{d}]", .{elem.elem_idx});
},
.offset_and_cast => |oac| if (oac.byte_offset == 0) {
try writer.print("@as({}, @ptrCast(", .{oac.new_ptr_ty.fmt(zcu)});
try printPtrDerivation(oac.parent.*, writer, level, zcu, opt_sema);
try writer.writeAll("))");
} else {
try writer.print("@as({}, @ptrFromInt(@intFromPtr(", .{oac.new_ptr_ty.fmt(zcu)});
try printPtrDerivation(oac.parent.*, writer, level, zcu, opt_sema);
try writer.print(") + {d}))", .{oac.byte_offset});
},
}
}