More specific errors.

[ErisianArchitect]

Description

Many of the result types returned &'static str, or otherwise a wrapper around &'static str. I tried to find as many instances of this as I could to make the errors more specific. I may have missed some things.

Related Issue

#595

How This Has Been Tested

Unfortunately, I'm unable to test it because the tests environment won't compile on my machine due to POSIX-only functionality.

#597

Option<Breaking Changes>

I felt that it was a good idea for errors to be more specific so that it would be easier to determine the source of the error.

Checklist

• I have read the Contributing Guide

[ErisianArchitect]

It seems that there are some tests failing due to my change to is_alignment_ok, removing the ability for 0 alignment. As far as I'm aware, 0 alignment should be invalid, so I think perhaps these tests should be removed.

[ErisianArchitect]

I looked into it some more, and I found this issue with this comment by one of the main contributors:

The "A value of 0 or" part of the docs is indeed incorrect. Zero is not a legal alignment.

Since 0 is not a legal alignment, I'm going to make the assumption that it's okay to remove these tests that check for an alignment of 0.

[ErisianArchitect]

I decided to do a test to see what would happen if you tried to set the alignment to 0 just to make sure that it really wasn't a legal value, and this was the result when I tried to build the module:

thread 'main' panicked at src\bin\defer_test\main.rs:567:25:
Module verification failed.: "huge alignment values are unsupported\n  %defer_stack = alloca inalloca swifterror { [5 x ptr], i64 }, align 9223372036854775808\n"

So it seems that setting the alignment to 0 can cause undesirable outcomes, so I think it's a good thing that I removed the ability for alignments to be 0.

Edit: This is on inkwell 0.6.0 with LLVM 18.1.

[TheDan64]

Isn't this >= 8?

[ErisianArchitect]

I just copied that message from the message that was passed into the BitwidthError, so if it's wrong then it was wrong before.

[TheDan64]

Looks good; just have one question to clarify before merging

[ErisianArchitect]

Any update on this?