~littleendian/xcore-todo#3: feat: safety checks with assert()

In Debug and ReleaseSafe modes std.debug.assert() asserts that the condition is true, orelse invokes illegal behaviour. In other modes it gets optimized away, which means that it won't impact the performance at all.

That said, safety-checked functions won't hurt, especially when they're likely to be misused by invalid data. This is a tradeoff between unchecked code that can do wacky stuff and unnecessary abstraction that can ruin the code base over time.

The task is to add safety-checks for Debug mode in functions that take in types that can't be of certain 'correct' value and might fail in case wrong value gets passed, e.g., when passing in a buffer that is zero-length.

Status: REPORTED
Submitter: ~littleendian
Assigned to: ~littleendian
Submitted: a month ago
Updated: a month ago
Labels: feature

~littleendian assigned ~littleendian a month ago

~littleendian added feature a month ago

~littleendian a month ago

Since commit 91e04e2c555736f4b35c797d371f4cd37ea4a4de there are a few things safety-checked:

x86.cpu.__readVendor:

Now checks if the provided buffer can contain 12 bytes or more.

x86.gdt.load:

Checks whether or not the last element in the provided table is a null entry.

x86.seg.reload:

Checks whether or not the actual segment selector is an executable one, if yes, fail.

NOTE: These safety-checks are ONLY AVAILABLE IN Debug and ReleaseSafe MODES. As a developer, if you build xcore in ReleaseFast or ReleaseSmall, your warranty is void, as the safety-checks will be omitted for performance reasons. If you develop like that, expect uncaught bugs.