llama_cpp_sys build issue: u8 vs i8 in APIs

[anisse]

An empty project with llama_cpp fails to build the sys crate, on rust 1.77.1, linux arm64:

248  |             llama_tokenize(
     |             -------------- arguments to this function are incorrect
249  |                 **self.model,
250  |                 content.as_ptr() as *const i8,
     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `*const u8`, found `*const i8`

Full details:

$ mkdir new-project
$ cd new-project
$ cargo init         
     Created binary (application) package
$ cargo add llama_cpp
    Updating crates.io index
      Adding llama_cpp v0.3.1 to dependencies.
             Features:
             + accel
             + avx
             + avx2
             + compat
             + f16c
             + fma
             + native
             - avx512
             - avx512_vmbi
             - avx512_vnni
             - blas
             - clblast
             - cuda
             - cuda_dmmv
             - cuda_f16
             - cuda_mmq
             - hipblas
             - metal
             - mpi
             - vulkan
    Updating crates.io index
$ rustc --version
rustc 1.77.1 (7cf61ebde 2024-03-27)
$ rustup show active-toolchain
stable-aarch64-unknown-linux-gnu (default)
$ cargo build
   Compiling proc-macro2 v1.0.79
   Compiling unicode-ident v1.0.12
   Compiling libc v0.2.153
   Compiling glob v0.3.1
   Compiling rustix v0.38.32
   Compiling prettyplease v0.2.17
   Compiling cfg-if v1.0.0
   Compiling either v1.10.0
   Compiling regex-syntax v0.8.3
   Compiling autocfg v1.2.0
   Compiling minimal-lexical v0.2.1
   Compiling memchr v2.7.2
   Compiling linux-raw-sys v0.4.13
   Compiling clang-sys v1.7.0
   Compiling bitflags v2.5.0
   Compiling slab v0.4.9
   Compiling quote v1.0.35
   Compiling nom v7.1.3
   Compiling libloading v0.8.3
   Compiling syn v2.0.58
   Compiling home v0.5.9
   Compiling once_cell v1.19.0
   Compiling pin-project-lite v0.2.14
   Compiling jobserver v0.1.28
   Compiling regex-automata v0.4.6
   Compiling bindgen v0.69.4
   Compiling cc v1.0.90
   Compiling itertools v0.12.1
   Compiling cexpr v0.6.0
   Compiling which v4.4.2
   Compiling futures-sink v0.3.30
   Compiling futures-core v0.3.30
   Compiling log v0.4.21
   Compiling shlex v1.3.0
   Compiling rustc-hash v1.1.0
   Compiling regex v1.10.4
   Compiling lazy_static v1.4.0
   Compiling lazycell v1.3.0
   Compiling futures-channel v0.3.30
   Compiling futures-io v0.3.30
   Compiling pin-utils v0.1.0
   Compiling futures-task v0.3.30
   Compiling syn v1.0.109
   Compiling thiserror v1.0.58
   Compiling tracing-core v0.1.32
   Compiling convert_case v0.4.0
   Compiling link-cplusplus v1.0.9
   Compiling tokio v1.37.0
   Compiling num_cpus v1.16.0
   Compiling futures-macro v0.3.30
   Compiling thiserror-impl v1.0.58
   Compiling tracing-attributes v0.1.27
   Compiling derive_more v0.99.17
   Compiling futures-util v0.3.30
   Compiling tracing v0.1.40
   Compiling llama_cpp_sys v0.3.1
   Compiling futures-executor v0.3.30
   Compiling futures v0.3.30
   Compiling llama_cpp v0.3.1
error[E0308]: mismatched types
    --> /home/anisse/.cargo/registry/src/index.crates.io-6f17d22bba15001f/llama_cpp-0.3.1/src/model/mod.rs:250:17
     |
248  |             llama_tokenize(
     |             -------------- arguments to this function are incorrect
249  |                 **self.model,
250  |                 content.as_ptr() as *const i8,
     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `*const u8`, found `*const i8`
     |
     = note: expected raw pointer `*const u8`
                found raw pointer `*const i8`
note: function defined here
    --> /home/anisse/dev/new-project/target/debug/build/llama_cpp_sys-a7988d5d0059f72f/out/bindings.rs:4019:12
     |
4019 |     pub fn llama_tokenize(
     |            ^^^^^^^^^^^^^^

error[E0308]: mismatched types
    --> /home/anisse/.cargo/registry/src/index.crates.io-6f17d22bba15001f/llama_cpp-0.3.1/src/model/mod.rs:326:17
     |
323  |             llama_token_to_piece(
     |             -------------------- arguments to this function are incorrect
...
326  |                 buffer.as_mut_ptr() as *mut i8,
     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `*mut u8`, found `*mut i8`
     |
     = note: expected raw pointer `*mut u8`
                found raw pointer `*mut i8`
note: function defined here
    --> /home/anisse/dev/new-project/target/debug/build/llama_cpp_sys-a7988d5d0059f72f/out/bindings.rs:4030:12
     |
4030 |     pub fn llama_token_to_piece(
     |            ^^^^^^^^^^^^^^^^^^^^

error[E0308]: mismatched types
    --> /home/anisse/.cargo/registry/src/index.crates.io-6f17d22bba15001f/llama_cpp-0.3.1/src/model/mod.rs:340:21
     |
337  |                 llama_token_to_piece(
     |                 -------------------- arguments to this function are incorrect
...
340  |                     buffer.as_mut_ptr() as *mut i8,
     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `*mut u8`, found `*mut i8`
     |
     = note: expected raw pointer `*mut u8`
                found raw pointer `*mut i8`
note: function defined here
    --> /home/anisse/dev/new-project/target/debug/build/llama_cpp_sys-a7988d5d0059f72f/out/bindings.rs:4030:12
     |
4030 |     pub fn llama_token_to_piece(
     |            ^^^^^^^^^^^^^^^^^^^^

error[E0308]: mismatched types
    --> /home/anisse/.cargo/registry/src/index.crates.io-6f17d22bba15001f/llama_cpp-0.3.1/src/model/mod.rs:382:21
     |
379  |                 llama_cpp_sys::llama_token_to_piece(
     |                 ----------------------------------- arguments to this function are incorrect
...
382  |                     token_buf.as_mut_ptr() as *mut i8,
     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `*mut u8`, found `*mut i8`
     |
     = note: expected raw pointer `*mut u8`
                found raw pointer `*mut i8`
note: function defined here
    --> /home/anisse/dev/new-project/target/debug/build/llama_cpp_sys-a7988d5d0059f72f/out/bindings.rs:4030:12
     |
4030 |     pub fn llama_token_to_piece(
     |            ^^^^^^^^^^^^^^^^^^^^

For more information about this error, try `rustc --explain E0308`.
error: could not compile `llama_cpp` (lib) due to 4 previous errors
$ 

[anisse]

Looks like it might be platform-specific... I tried to fix it and failed: https://github.com/anisse/llama_cpp-rs/actions/runs/8569447184/job/23485360455#step:5:297

[pedro-devv]

I've made some changes that should fix the issue, please let me know if it persists after I merge them.

[anisse]

Thank you, I confirmed this fixed the issue.