remove obsolete dl module (#118)

Signed-off-by: Joel Dice <joel.dice@fermyon.com>
Co-authored-by: Joel Dice <joel.dice@fermyon.com>

Author: benbrandt

runtime/src/lib.rs

@@ -1099,179 +1099,6 @@ pub extern "C" fn componentize_py_to_canon_handle(
     }
 }
 
-// TODO: Update to the latest `wit-component`, which has a `use_built_in_libdl` option that makes the following
-// unecessary:
-pub mod dl {
-    use std::{
-        ffi::{c_char, c_int, c_void, CStr},
-        ptr, slice,
-    };
-
-    const RTLD_LAZY: c_int = 1;
-    const RTLD_NOW: c_int = 2;
-
-    const RTLD_NEXT: isize = -1;
-    const RTLD_DEFAULT: isize = 0;
-
-    #[repr(C)]
-    pub struct Name {
-        length: u32,
-        data: *const u8,
-    }
-
-    #[repr(C)]
-    pub struct Symbol {
-        name: Name,
-        address: *const c_void,
-    }
-
-    #[repr(C)]
-    pub struct Symbols {
-        count: u32,
-        symbols: *const Symbol,
-    }
-
-    #[repr(C)]
-    pub struct Library {
-        name: Name,
-        symbols: Symbols,
-    }
-
-    #[repr(C)]
-    pub struct Libraries {
-        count: u32,
-        libraries: *const Library,
-    }
-
-    struct Pointer<T>(*const T);
-
-    unsafe impl<T> Sync for Pointer<T> {}
-
-    static mut ERROR: Pointer<c_char> = Pointer(ptr::null());
-    static mut LIBRARIES: Pointer<Libraries> = Pointer(ptr::null());
-
-    unsafe fn invalid_handle(library: *const c_void) -> bool {
-        if LIBRARIES.0.is_null() {
-            panic!(
-                "`__wasm_set_libraries` should have been called during \
-                 instantiation with a non-NULL value"
-            );
-        }
-
-        let library = library as *const Library;
-        if (0..(*LIBRARIES.0).count).any(|index| {
-            (*LIBRARIES.0)
-                .libraries
-                .add(usize::try_from(index).unwrap())
-                == library
-        }) {
-            false
-        } else {
-            ERROR.0 = b"invalid library handle\0" as *const _ as _;
-            true
-        }
-    }
-
-    /// # Safety
-    /// TODO
-    #[no_mangle]
-    pub unsafe extern "C" fn dlclose(library: *mut c_void) -> c_int {
-        if invalid_handle(library) {
-            -1
-        } else {
-            0
-        }
-    }
-
-    /// # Safety
-    /// TODO
-    #[no_mangle]
-    pub unsafe extern "C" fn dlerror() -> *const c_char {
-        let value = ERROR.0;
-        ERROR.0 = ptr::null();
-        value
-    }
-
-    /// # Safety
-    /// TODO
-    #[no_mangle]
-    pub unsafe extern "C" fn dlopen(name: *const c_char, flags: c_int) -> *const c_void {
-        if LIBRARIES.0.is_null() {
-            panic!(
-                "`__wasm_set_libraries` should have been called during \
-                 instantiation with a non-NULL value"
-            );
-        }
-
-        if (flags & !(RTLD_LAZY | RTLD_NOW)) != 0 {
-            // TODO
-            ERROR.0 = b"dlopen flags not yet supported\0" as *const _ as _;
-            return ptr::null();
-        }
-
-        let name = CStr::from_ptr(name);
-        let name = name.to_bytes();
-        let libraries = slice::from_raw_parts(
-            (*LIBRARIES.0).libraries,
-            usize::try_from((*LIBRARIES.0).count).unwrap(),
-        );
-        if let Ok(index) = libraries.binary_search_by(|library| {
-            slice::from_raw_parts(
-                library.name.data,
-                usize::try_from(library.name.length).unwrap(),
-            )
-            .cmp(name)
-        }) {
-            &libraries[index] as *const _ as _
-        } else {
-            ERROR.0 = "library not found\0" as *const _ as _;
-            ptr::null()
-        }
-    }
-
-    /// # Safety
-    /// TODO
-    #[no_mangle]
-    pub unsafe extern "C" fn dlsym(library: *const c_void, name: *const c_char) -> *const c_void {
-        if library as isize == RTLD_NEXT || library as isize == RTLD_DEFAULT {
-            // TODO
-            ERROR.0 = "dlsym RTLD_NEXT and RTLD_DEFAULT not yet supported\0" as *const _ as _;
-            return ptr::null();
-        }
-
-        if invalid_handle(library) {
-            return ptr::null();
-        }
-
-        let library = library as *const Library;
-        let name = CStr::from_ptr(name);
-        let name = name.to_bytes();
-        let symbols = slice::from_raw_parts(
-            (*library).symbols.symbols,
-            usize::try_from((*library).symbols.count).unwrap(),
-        );
-        if let Ok(index) = symbols.binary_search_by(|symbol| {
-            slice::from_raw_parts(
-                symbol.name.data,
-                usize::try_from(symbol.name.length).unwrap(),
-            )
-            .cmp(name)
-        }) {
-            symbols[index].address
-        } else {
-            ERROR.0 = "library not found\0" as *const _ as _;
-            ptr::null()
-        }
-    }
-
-    /// # Safety
-    /// TODO
-    #[no_mangle]
-    pub unsafe extern "C" fn __wasm_set_libraries(libraries: *const Libraries) {
-        LIBRARIES.0 = libraries;
-    }
-}
-
 // As of this writing, recent Rust `nightly` builds include a version of the `libc` crate that expects `wasi-libc`
 // to define the following global variables, but `wasi-libc` defines them as preprocessor constants which aren't
 // visible at link time, so we need to define them somewhere.  Ideally, we should fix this upstream, but for now we

src/lib.rs

@@ -280,7 +280,9 @@ pub async fn componentize(
     });
 
     // Link all the libraries (including any native extensions) into a single component.
-    let mut linker = wit_component::Linker::default().validate(true);
+    let mut linker = wit_component::Linker::default()
+        .validate(true)
+        .use_built_in_libdl(true);
 
     for Library {
         name,