From: Phillip Wood Date: Mon, 28 Jul 2025 19:52:48 GMT Subject: Re: [PATCH 4/7] xdiff: make fields of xrecord_t Rust friendly Message-ID: In-Reply-To: On 28/07/2025 20:34, Ezekiel Newren wrote: > On Fri, Jul 18, 2025 at 7:35 AM Phillip Wood wrote: >> On 17/07/2025 21:32, Ezekiel Newren via GitGitGadget wrote: >>> From: Ezekiel Newren >>> >>> A few commits ago, we added definitions for Rust primitive types, >>> to facilitate interoperability between C and Rust. Switch a >>> few variables to use these types. Which, for now, will >>> require adding some casts. >> >> How necessary is it to change char' to 'u8' so long as the rust and C >> sides both use a type that is the same size? Also what's the advantage >> of using these typedefs rather than the normal C types like unit8_t ? > > Rust defines char as 32 bits. C treats char as signed 8 bits. What git > really means by char* is treat everything like a byte string, and u8 > is how raw bytes are handled in Rust. Right - we need to use u8 on the rust side but I'm trying to understand why we need to change the type on the C side and why do we need typedefs like usize and u32 on the C side when we already have size_t and uint32_t? Thanks Phillip >>> diff --git a/xdiff/xdiffi.c b/xdiff/xdiffi.c >>> index 5a96e36dfbea..3b364c61f671 100644 >>> --- a/xdiff/xdiffi.c >>> +++ b/xdiff/xdiffi.c >>> @@ -418,7 +418,7 @@ static int get_indent(xrecord_t *rec) >>> long i; >>> int ret = 0; >>> >>> - for (i = 0; i < rec->size; i++) { >>> + for (i = 0; i < (long) rec->size; i++) { >> >> i is a loop counter and array index so we can lose this cast by >> changeing i to size_t > > Ok, but I'm going to change the type of i to usize and stuff it inside > the loop i.e. for (usize i = 0; ... > >> Thanks >> >> Phillip