zig/test/behavior/for.zig
Andrew Kelley 74db8c2e83 omit safety checks for element access in for loops
One of the main points of for loops is that you can safety check the
length once, before entering the loop, and then safely assume that every
element inside the loop is in bounds.

In master branch, the safety checks are incorrectly intact even inside
for loops. This commit fixes it. It's especially nice with multi-object
loops because the number of elided checks is N * M where N is how many
iterations and M is how many objects.
2023-02-18 19:20:19 -07:00

381 lines
11 KiB
Zig

const builtin = @import("builtin");
const std = @import("std");
const expect = std.testing.expect;
const expectEqual = std.testing.expectEqual;
const mem = std.mem;
test "continue in for loop" {
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
const array = [_]i32{ 1, 2, 3, 4, 5 };
var sum: i32 = 0;
for (array) |x| {
sum += x;
if (x < 3) {
continue;
}
break;
}
if (sum != 6) unreachable;
}
test "break from outer for loop" {
try testBreakOuter();
comptime try testBreakOuter();
}
fn testBreakOuter() !void {
var array = "aoeu";
var count: usize = 0;
outer: for (array) |_| {
for (array) |_| {
count += 1;
break :outer;
}
}
try expect(count == 1);
}
test "continue outer for loop" {
try testContinueOuter();
comptime try testContinueOuter();
}
fn testContinueOuter() !void {
var array = "aoeu";
var counter: usize = 0;
outer: for (array) |_| {
for (array) |_| {
counter += 1;
continue :outer;
}
}
try expect(counter == array.len);
}
test "ignore lval with underscore (for loop)" {
for ([_]void{}, 0..) |_, i| {
_ = i;
for ([_]void{}, 0..) |_, j| {
_ = j;
break;
}
break;
}
}
test "basic for loop" {
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
const expected_result = [_]u8{ 9, 8, 7, 6, 0, 1, 2, 3 } ** 3;
var buffer: [expected_result.len]u8 = undefined;
var buf_index: usize = 0;
const array = [_]u8{ 9, 8, 7, 6 };
for (array) |item| {
buffer[buf_index] = item;
buf_index += 1;
}
for (array, 0..) |item, index| {
_ = item;
buffer[buf_index] = @intCast(u8, index);
buf_index += 1;
}
const array_ptr = &array;
for (array_ptr) |item| {
buffer[buf_index] = item;
buf_index += 1;
}
for (array_ptr, 0..) |item, index| {
_ = item;
buffer[buf_index] = @intCast(u8, index);
buf_index += 1;
}
const unknown_size: []const u8 = &array;
for (unknown_size) |item| {
buffer[buf_index] = item;
buf_index += 1;
}
for (unknown_size, 0..) |_, index| {
buffer[buf_index] = @intCast(u8, index);
buf_index += 1;
}
try expect(mem.eql(u8, buffer[0..buf_index], &expected_result));
}
test "for with null and T peer types and inferred result location type" {
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
const S = struct {
fn doTheTest(slice: []const u8) !void {
if (for (slice) |item| {
if (item == 10) {
break item;
}
} else null) |v| {
_ = v;
@panic("fail");
}
}
};
try S.doTheTest(&[_]u8{ 1, 2 });
comptime try S.doTheTest(&[_]u8{ 1, 2 });
}
test "2 break statements and an else" {
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
const S = struct {
fn entry(t: bool, f: bool) !void {
var buf: [10]u8 = undefined;
var ok = false;
ok = for (buf) |item| {
_ = item;
if (f) break false;
if (t) break true;
} else false;
try expect(ok);
}
};
try S.entry(true, false);
comptime try S.entry(true, false);
}
test "for loop with pointer elem var" {
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
const source = "abcdefg";
var target: [source.len]u8 = undefined;
mem.copy(u8, target[0..], source);
mangleString(target[0..]);
try expect(mem.eql(u8, &target, "bcdefgh"));
for (source, 0..) |*c, i| {
_ = i;
try expect(@TypeOf(c) == *const u8);
}
for (&target, 0..) |*c, i| {
_ = i;
try expect(@TypeOf(c) == *u8);
}
}
fn mangleString(s: []u8) void {
for (s) |*c| {
c.* += 1;
}
}
test "for copies its payload" {
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
const S = struct {
fn doTheTest() !void {
var x = [_]usize{ 1, 2, 3 };
for (x, 0..) |value, i| {
// Modify the original array
x[i] += 99;
try expect(value == i + 1);
}
}
};
try S.doTheTest();
comptime try S.doTheTest();
}
test "for on slice with allowzero ptr" {
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
const S = struct {
fn doTheTest(slice: []const u8) !void {
var ptr = @ptrCast([*]allowzero const u8, slice.ptr)[0..slice.len];
for (ptr, 0..) |x, i| try expect(x == i + 1);
for (ptr, 0..) |*x, i| try expect(x.* == i + 1);
}
};
try S.doTheTest(&[_]u8{ 1, 2, 3, 4 });
comptime try S.doTheTest(&[_]u8{ 1, 2, 3, 4 });
}
test "else continue outer for" {
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
var i: usize = 6;
var buf: [5]u8 = undefined;
while (true) {
i -= 1;
for (buf[i..5]) |_| {
return;
} else continue;
}
}
test "for loop with else branch" {
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
{
var x = [_]u32{ 1, 2 };
const q = for (x) |y| {
if ((y & 1) != 0) continue;
break y * 2;
} else @as(u32, 1);
try expect(q == 4);
}
{
var x = [_]u32{ 1, 2 };
const q = for (x) |y| {
if ((y & 1) != 0) continue;
break y * 2;
} else @panic("");
try expect(q == 4);
}
}
test "count over fixed range" {
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
var sum: usize = 0;
for (0..6) |i| {
sum += i;
}
try expect(sum == 15);
}
test "two counters" {
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
var sum: usize = 0;
for (0..10, 10..20) |i, j| {
sum += 1;
try expect(i + 10 == j);
}
try expect(sum == 10);
}
test "1-based counter and ptr to array" {
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
var ok: usize = 0;
for (1..6, "hello") |i, b| {
if (i == 1) {
try expect(b == 'h');
ok += 1;
}
if (i == 2) {
try expect(b == 'e');
ok += 1;
}
if (i == 3) {
try expect(b == 'l');
ok += 1;
}
if (i == 4) {
try expect(b == 'l');
ok += 1;
}
if (i == 5) {
try expect(b == 'o');
ok += 1;
}
}
try expect(ok == 5);
}
test "slice and two counters, one is offset and one is runtime" {
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
const slice: []const u8 = "blah";
var start: usize = 0;
for (slice, start..4, 1..5) |a, b, c| {
if (a == 'b') {
try expect(b == 0);
try expect(c == 1);
}
if (a == 'l') {
try expect(b == 1);
try expect(c == 2);
}
if (a == 'a') {
try expect(b == 2);
try expect(c == 3);
}
if (a == 'h') {
try expect(b == 3);
try expect(c == 4);
}
}
}
test "two slices, one captured by-ref" {
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
var buf: [10]u8 = undefined;
const slice1: []const u8 = "blah";
const slice2: []u8 = buf[0..4];
for (slice1, slice2) |a, *b| {
b.* = a;
}
try expect(slice2[0] == 'b');
try expect(slice2[1] == 'l');
try expect(slice2[2] == 'a');
try expect(slice2[3] == 'h');
}
test "raw pointer and slice" {
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
var buf: [10]u8 = undefined;
const slice: []const u8 = "blah";
const ptr: [*]u8 = buf[0..4];
for (ptr, slice) |*a, b| {
a.* = b;
}
try expect(buf[0] == 'b');
try expect(buf[1] == 'l');
try expect(buf[2] == 'a');
try expect(buf[3] == 'h');
}