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authorAndrew Kelley <andrew@ziglang.org>2021-02-25 21:04:23 -0700
committerAndrew Kelley <andrew@ziglang.org>2021-02-25 21:04:23 -0700
commit0b58b617998b79a765b54f88fbe90ca2798b3d3e (patch)
treeca6cc4b6bcc2b93166d196049ee49416afe781ad /lib/std/multi_array_list.zig
parentdc325669e360f7a9dfa24f85a62fa386529dade6 (diff)
parentfd208d9d5913a0929e444deb97b91092c427bb14 (diff)
downloadzig-0b58b617998b79a765b54f88fbe90ca2798b3d3e.tar.gz
zig-0b58b617998b79a765b54f88fbe90ca2798b3d3e.zip
Merge remote-tracking branch 'origin/master' into llvm12
Conflicts: * src/clang.zig * src/llvm.zig - this file got moved to src/llvm/bindings.zig in master branch so I had to put the new LLVM arch/os enum tags into it. * lib/std/target.zig, src/stage1/target.cpp - haiku had an inconsistency with its default target ABI, gnu vs eabi. In this commit we make it gnu in both places to match the latest changes by @hoanga. * src/translate_c.zig
Diffstat (limited to 'lib/std/multi_array_list.zig')
-rw-r--r--lib/std/multi_array_list.zig446
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diff --git a/lib/std/multi_array_list.zig b/lib/std/multi_array_list.zig
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+// SPDX-License-Identifier: MIT
+// Copyright (c) 2015-2021 Zig Contributors
+// This file is part of [zig](https://ziglang.org/), which is MIT licensed.
+// The MIT license requires this copyright notice to be included in all copies
+// and substantial portions of the software.
+const std = @import("std.zig");
+const assert = std.debug.assert;
+const meta = std.meta;
+const mem = std.mem;
+const Allocator = mem.Allocator;
+
+pub fn MultiArrayList(comptime S: type) type {
+ return struct {
+ bytes: [*]align(@alignOf(S)) u8 = undefined,
+ len: usize = 0,
+ capacity: usize = 0,
+
+ pub const Elem = S;
+
+ pub const Field = meta.FieldEnum(S);
+
+ pub const Slice = struct {
+ /// This array is indexed by the field index which can be obtained
+ /// by using @enumToInt() on the Field enum
+ ptrs: [fields.len][*]u8,
+ len: usize,
+ capacity: usize,
+
+ pub fn items(self: Slice, comptime field: Field) []FieldType(field) {
+ const byte_ptr = self.ptrs[@enumToInt(field)];
+ const F = FieldType(field);
+ const casted_ptr = @ptrCast([*]F, @alignCast(@alignOf(F), byte_ptr));
+ return casted_ptr[0..self.len];
+ }
+
+ pub fn toMultiArrayList(self: Slice) Self {
+ if (self.ptrs.len == 0) {
+ return .{};
+ }
+ const unaligned_ptr = self.ptrs[sizes.fields[0]];
+ 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,
+ .capacity = self.capacity,
+ };
+ }
+
+ pub fn deinit(self: *Slice, gpa: *Allocator) void {
+ var other = self.toMultiArrayList();
+ other.deinit(gpa);
+ self.* = undefined;
+ }
+ };
+
+ const Self = @This();
+
+ const fields = meta.fields(S);
+ /// `sizes.bytes` is an array of @sizeOf each S field. Sorted by alignment, descending.
+ /// `sizes.fields` is an array mapping from `sizes.bytes` array index to field index.
+ const sizes = blk: {
+ const Data = struct {
+ size: usize,
+ size_index: usize,
+ alignment: usize,
+ };
+ var data: [fields.len]Data = undefined;
+ for (fields) |field_info, i| {
+ data[i] = .{
+ .size = @sizeOf(field_info.field_type),
+ .size_index = i,
+ .alignment = field_info.alignment,
+ };
+ }
+ const Sort = struct {
+ fn lessThan(trash: *i32, lhs: Data, rhs: Data) bool {
+ return lhs.alignment >= rhs.alignment;
+ }
+ };
+ var trash: i32 = undefined; // workaround for stage1 compiler bug
+ std.sort.sort(Data, &data, &trash, Sort.lessThan);
+ var sizes_bytes: [fields.len]usize = undefined;
+ var field_indexes: [fields.len]usize = undefined;
+ for (data) |elem, i| {
+ sizes_bytes[i] = elem.size;
+ field_indexes[i] = elem.size_index;
+ }
+ break :blk .{
+ .bytes = sizes_bytes,
+ .fields = field_indexes,
+ };
+ };
+
+ /// Release all allocated memory.
+ pub fn deinit(self: *Self, gpa: *Allocator) void {
+ gpa.free(self.allocatedBytes());
+ self.* = undefined;
+ }
+
+ /// The caller owns the returned memory. Empties this MultiArrayList.
+ pub fn toOwnedSlice(self: *Self) Slice {
+ const result = self.slice();
+ self.* = .{};
+ return result;
+ }
+
+ pub fn slice(self: Self) Slice {
+ var result: Slice = .{
+ .ptrs = undefined,
+ .len = self.len,
+ .capacity = self.capacity,
+ };
+ var ptr: [*]u8 = self.bytes;
+ for (sizes.bytes) |field_size, i| {
+ result.ptrs[sizes.fields[i]] = ptr;
+ ptr += field_size * self.capacity;
+ }
+ return result;
+ }
+
+ pub fn items(self: Self, comptime field: Field) []FieldType(field) {
+ return self.slice().items(field);
+ }
+
+ /// Overwrite one array element with new data.
+ pub fn set(self: *Self, index: usize, elem: S) void {
+ const slices = self.slice();
+ inline for (fields) |field_info, i| {
+ slices.items(@intToEnum(Field, i))[index] = @field(elem, field_info.name);
+ }
+ }
+
+ /// Obtain all the data for one array element.
+ pub fn get(self: *Self, index: usize) S {
+ const slices = self.slice();
+ var result: S = undefined;
+ inline for (fields) |field_info, i| {
+ @field(elem, field_info.name) = slices.items(@intToEnum(Field, i))[index];
+ }
+ return result;
+ }
+
+ /// Extend the list by 1 element. Allocates more memory as necessary.
+ pub fn append(self: *Self, gpa: *Allocator, elem: S) !void {
+ try self.ensureCapacity(gpa, self.len + 1);
+ self.appendAssumeCapacity(elem);
+ }
+
+ /// Extend the list by 1 element, but asserting `self.capacity`
+ /// is sufficient to hold an additional item.
+ pub fn appendAssumeCapacity(self: *Self, elem: S) void {
+ assert(self.len < self.capacity);
+ self.len += 1;
+ self.set(self.len - 1, elem);
+ }
+
+ /// Adjust the list's length to `new_len`.
+ /// Does not initialize added items, if any.
+ pub fn resize(self: *Self, gpa: *Allocator, new_len: usize) !void {
+ try self.ensureCapacity(gpa, new_len);
+ self.len = new_len;
+ }
+
+ /// Attempt to reduce allocated capacity to `new_len`.
+ /// If `new_len` is greater than zero, this may fail to reduce the capacity,
+ /// but the data remains intact and the length is updated to new_len.
+ pub fn shrinkAndFree(self: *Self, gpa: *Allocator, new_len: usize) void {
+ if (new_len == 0) {
+ gpa.free(self.allocatedBytes());
+ self.* = .{};
+ return;
+ }
+ assert(new_len <= self.capacity);
+ assert(new_len <= self.len);
+
+ const other_bytes = gpa.allocAdvanced(
+ u8,
+ @alignOf(S),
+ capacityInBytes(new_len),
+ .exact,
+ ) catch {
+ const self_slice = self.slice();
+ inline for (fields) |field_info, i| {
+ const field = @intToEnum(Field, i);
+ const dest_slice = self_slice.items(field)[new_len..];
+ const byte_count = dest_slice.len * @sizeOf(field_info.field_type);
+ // We use memset here for more efficient codegen in safety-checked,
+ // valgrind-enabled builds. Otherwise the valgrind client request
+ // will be repeated for every element.
+ @memset(@ptrCast([*]u8, dest_slice.ptr), undefined, byte_count);
+ }
+ self.len = new_len;
+ return;
+ };
+ var other = Self{
+ .bytes = other_bytes.ptr,
+ .capacity = new_len,
+ .len = new_len,
+ };
+ self.len = new_len;
+ const self_slice = self.slice();
+ const other_slice = other.slice();
+ inline for (fields) |field_info, i| {
+ const field = @intToEnum(Field, i);
+ // TODO we should be able to use std.mem.copy here but it causes a
+ // test failure on aarch64 with -OReleaseFast
+ const src_slice = mem.sliceAsBytes(self_slice.items(field));
+ const dst_slice = mem.sliceAsBytes(other_slice.items(field));
+ @memcpy(dst_slice.ptr, src_slice.ptr, src_slice.len);
+ }
+ gpa.free(self.allocatedBytes());
+ self.* = other;
+ }
+
+ /// Reduce length to `new_len`.
+ /// Invalidates pointers to elements `items[new_len..]`.
+ /// Keeps capacity the same.
+ pub fn shrinkRetainingCapacity(self: *Self, new_len: usize) void {
+ self.len = new_len;
+ }
+
+ /// Modify the array so that it can hold at least `new_capacity` items.
+ /// Implements super-linear growth to achieve amortized O(1) append operations.
+ /// Invalidates pointers if additional memory is needed.
+ pub fn ensureCapacity(self: *Self, gpa: *Allocator, new_capacity: usize) !void {
+ var better_capacity = self.capacity;
+ if (better_capacity >= new_capacity) return;
+
+ while (true) {
+ better_capacity += better_capacity / 2 + 8;
+ if (better_capacity >= new_capacity) break;
+ }
+
+ return self.setCapacity(gpa, better_capacity);
+ }
+
+ /// Modify the array so that it can hold exactly `new_capacity` items.
+ /// Invalidates pointers if additional memory is needed.
+ /// `new_capacity` must be greater or equal to `len`.
+ pub fn setCapacity(self: *Self, gpa: *Allocator, new_capacity: usize) !void {
+ assert(new_capacity >= self.len);
+ const new_bytes = try gpa.allocAdvanced(
+ u8,
+ @alignOf(S),
+ capacityInBytes(new_capacity),
+ .exact,
+ );
+ if (self.len == 0) {
+ self.bytes = new_bytes.ptr;
+ self.capacity = new_capacity;
+ return;
+ }
+ var other = Self{
+ .bytes = new_bytes.ptr,
+ .capacity = new_capacity,
+ .len = self.len,
+ };
+ const self_slice = self.slice();
+ const other_slice = other.slice();
+ inline for (fields) |field_info, i| {
+ const field = @intToEnum(Field, i);
+ // TODO we should be able to use std.mem.copy here but it causes a
+ // test failure on aarch64 with -OReleaseFast
+ const src_slice = mem.sliceAsBytes(self_slice.items(field));
+ const dst_slice = mem.sliceAsBytes(other_slice.items(field));
+ @memcpy(dst_slice.ptr, src_slice.ptr, src_slice.len);
+ }
+ gpa.free(self.allocatedBytes());
+ self.* = other;
+ }
+
+ fn capacityInBytes(capacity: usize) usize {
+ const sizes_vector: std.meta.Vector(sizes.bytes.len, usize) = sizes.bytes;
+ const capacity_vector = @splat(sizes.bytes.len, capacity);
+ return @reduce(.Add, capacity_vector * sizes_vector);
+ }
+
+ fn allocatedBytes(self: Self) []align(@alignOf(S)) u8 {
+ return self.bytes[0..capacityInBytes(self.capacity)];
+ }
+
+ fn FieldType(field: Field) type {
+ return meta.fieldInfo(S, field).field_type;
+ }
+ };
+}
+
+test "basic usage" {
+ const testing = std.testing;
+ const ally = testing.allocator;
+
+ const Foo = struct {
+ a: u32,
+ b: []const u8,
+ c: u8,
+ };
+
+ var list = MultiArrayList(Foo){};
+ defer list.deinit(ally);
+
+ try list.ensureCapacity(ally, 2);
+
+ list.appendAssumeCapacity(.{
+ .a = 1,
+ .b = "foobar",
+ .c = 'a',
+ });
+
+ list.appendAssumeCapacity(.{
+ .a = 2,
+ .b = "zigzag",
+ .c = 'b',
+ });
+
+ testing.expectEqualSlices(u32, list.items(.a), &[_]u32{ 1, 2 });
+ testing.expectEqualSlices(u8, list.items(.c), &[_]u8{ 'a', 'b' });
+
+ testing.expectEqual(@as(usize, 2), list.items(.b).len);
+ testing.expectEqualStrings("foobar", list.items(.b)[0]);
+ testing.expectEqualStrings("zigzag", list.items(.b)[1]);
+
+ try list.append(ally, .{
+ .a = 3,
+ .b = "fizzbuzz",
+ .c = 'c',
+ });
+
+ testing.expectEqualSlices(u32, list.items(.a), &[_]u32{ 1, 2, 3 });
+ testing.expectEqualSlices(u8, list.items(.c), &[_]u8{ 'a', 'b', 'c' });
+
+ testing.expectEqual(@as(usize, 3), list.items(.b).len);
+ testing.expectEqualStrings("foobar", list.items(.b)[0]);
+ testing.expectEqualStrings("zigzag", list.items(.b)[1]);
+ testing.expectEqualStrings("fizzbuzz", list.items(.b)[2]);
+
+ // Add 6 more things to force a capacity increase.
+ var i: usize = 0;
+ while (i < 6) : (i += 1) {
+ try list.append(ally, .{
+ .a = @intCast(u32, 4 + i),
+ .b = "whatever",
+ .c = @intCast(u8, 'd' + i),
+ });
+ }
+
+ testing.expectEqualSlices(
+ u32,
+ &[_]u32{ 1, 2, 3, 4, 5, 6, 7, 8, 9 },
+ list.items(.a),
+ );
+ testing.expectEqualSlices(
+ u8,
+ &[_]u8{ 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i' },
+ list.items(.c),
+ );
+
+ list.shrinkAndFree(ally, 3);
+
+ testing.expectEqualSlices(u32, list.items(.a), &[_]u32{ 1, 2, 3 });
+ testing.expectEqualSlices(u8, list.items(.c), &[_]u8{ 'a', 'b', 'c' });
+
+ testing.expectEqual(@as(usize, 3), list.items(.b).len);
+ testing.expectEqualStrings("foobar", list.items(.b)[0]);
+ testing.expectEqualStrings("zigzag", list.items(.b)[1]);
+ testing.expectEqualStrings("fizzbuzz", list.items(.b)[2]);
+}
+
+// This was observed to fail on aarch64 with LLVM 11, when the capacityInBytes
+// function used the @reduce code path.
+test "regression test for @reduce bug" {
+ const ally = std.testing.allocator;
+ var list = MultiArrayList(struct {
+ tag: std.zig.Token.Tag,
+ start: u32,
+ }){};
+ defer list.deinit(ally);
+
+ try list.ensureCapacity(ally, 20);
+
+ try list.append(ally, .{ .tag = .keyword_const, .start = 0 });
+ try list.append(ally, .{ .tag = .identifier, .start = 6 });
+ try list.append(ally, .{ .tag = .equal, .start = 10 });
+ try list.append(ally, .{ .tag = .builtin, .start = 12 });
+ try list.append(ally, .{ .tag = .l_paren, .start = 19 });
+ try list.append(ally, .{ .tag = .string_literal, .start = 20 });
+ try list.append(ally, .{ .tag = .r_paren, .start = 25 });
+ try list.append(ally, .{ .tag = .semicolon, .start = 26 });
+ try list.append(ally, .{ .tag = .keyword_pub, .start = 29 });
+ try list.append(ally, .{ .tag = .keyword_fn, .start = 33 });
+ try list.append(ally, .{ .tag = .identifier, .start = 36 });
+ try list.append(ally, .{ .tag = .l_paren, .start = 40 });
+ try list.append(ally, .{ .tag = .r_paren, .start = 41 });
+ try list.append(ally, .{ .tag = .identifier, .start = 43 });
+ try list.append(ally, .{ .tag = .bang, .start = 51 });
+ try list.append(ally, .{ .tag = .identifier, .start = 52 });
+ try list.append(ally, .{ .tag = .l_brace, .start = 57 });
+ try list.append(ally, .{ .tag = .identifier, .start = 63 });
+ try list.append(ally, .{ .tag = .period, .start = 66 });
+ try list.append(ally, .{ .tag = .identifier, .start = 67 });
+ try list.append(ally, .{ .tag = .period, .start = 70 });
+ try list.append(ally, .{ .tag = .identifier, .start = 71 });
+ try list.append(ally, .{ .tag = .l_paren, .start = 75 });
+ try list.append(ally, .{ .tag = .string_literal, .start = 76 });
+ try list.append(ally, .{ .tag = .comma, .start = 113 });
+ try list.append(ally, .{ .tag = .period, .start = 115 });
+ try list.append(ally, .{ .tag = .l_brace, .start = 116 });
+ try list.append(ally, .{ .tag = .r_brace, .start = 117 });
+ try list.append(ally, .{ .tag = .r_paren, .start = 118 });
+ try list.append(ally, .{ .tag = .semicolon, .start = 119 });
+ try list.append(ally, .{ .tag = .r_brace, .start = 121 });
+ try list.append(ally, .{ .tag = .eof, .start = 123 });
+
+ const tags = list.items(.tag);
+ std.testing.expectEqual(tags[1], .identifier);
+ std.testing.expectEqual(tags[2], .equal);
+ std.testing.expectEqual(tags[3], .builtin);
+ std.testing.expectEqual(tags[4], .l_paren);
+ std.testing.expectEqual(tags[5], .string_literal);
+ std.testing.expectEqual(tags[6], .r_paren);
+ std.testing.expectEqual(tags[7], .semicolon);
+ std.testing.expectEqual(tags[8], .keyword_pub);
+ std.testing.expectEqual(tags[9], .keyword_fn);
+ std.testing.expectEqual(tags[10], .identifier);
+ std.testing.expectEqual(tags[11], .l_paren);
+ std.testing.expectEqual(tags[12], .r_paren);
+ std.testing.expectEqual(tags[13], .identifier);
+ std.testing.expectEqual(tags[14], .bang);
+ std.testing.expectEqual(tags[15], .identifier);
+ std.testing.expectEqual(tags[16], .l_brace);
+ std.testing.expectEqual(tags[17], .identifier);
+ std.testing.expectEqual(tags[18], .period);
+ std.testing.expectEqual(tags[19], .identifier);
+ std.testing.expectEqual(tags[20], .period);
+ std.testing.expectEqual(tags[21], .identifier);
+ std.testing.expectEqual(tags[22], .l_paren);
+ std.testing.expectEqual(tags[23], .string_literal);
+ std.testing.expectEqual(tags[24], .comma);
+ std.testing.expectEqual(tags[25], .period);
+ std.testing.expectEqual(tags[26], .l_brace);
+ std.testing.expectEqual(tags[27], .r_brace);
+ std.testing.expectEqual(tags[28], .r_paren);
+ std.testing.expectEqual(tags[29], .semicolon);
+ std.testing.expectEqual(tags[30], .r_brace);
+ std.testing.expectEqual(tags[31], .eof);
+}