motiejus/zig
1
Fork 0
Code Releases Activity

Sema: allow comptime mutation of multiple array elements

Browse Source 
Previously, if you had a pointer to multiple array elements and tried to
write to it at comptime, it was incorrectly treated as a pointer to one
specific array value, leading to an assertion down the line. If we try
to mutate a value at an elem_ptr larger than the element type, we need
to perform a modification to multiple array elements.

This solution isn't ideal, since it will result in storePtrVal
serializing the whole array, modifying the relevant parts, and storing
it back. Ideally, it would only take the required elements. However,
this change would have been more complex, and this is a fairly rare
operation (nobody ever ran into the bug before after all), so it doesn't
matter all that much.
This commit is contained in:
mlugg
2023-03-03 21:13:31 +00:00
committed by Veikka Tuominen
parent 5a12d00708
commit 1e6d7f7763
3 changed files with 42 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

27
test/behavior/array.zig
View File

@@ -48,16 +48,23 @@ fn getArrayLen(a: []const u32) usize {
test "array concat with undefined" {
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
{
var array = "hello".* ++ @as([5]u8, undefined);
array[5..10].* = "world".*;
try std.testing.expect(std.mem.eql(u8, &array, "helloworld"));
}
{
var array = @as([5]u8, undefined) ++ "world".*;
array[0..5].* = "hello".*;
try std.testing.expect(std.mem.eql(u8, &array, "helloworld"));
}
const S = struct {
fn doTheTest() !void {
{
var array = "hello".* ++ @as([5]u8, undefined);
array[5..10].* = "world".*;
try std.testing.expect(std.mem.eql(u8, &array, "helloworld"));
}
{
var array = @as([5]u8, undefined) ++ "world".*;
array[0..5].* = "hello".*;
try std.testing.expect(std.mem.eql(u8, &array, "helloworld"));
}
}
};
try S.doTheTest();
comptime try S.doTheTest();
}
test "array concat with tuple" {