Replace prebuild binary dll's with a version build at test time

This commit replaces the prebuild bin dlls with using a dll build at
test time.

Author: weiznich

Cargo.toml

@@ -14,7 +14,8 @@ keywords = ["dlopen", "load", "shared", "dylib"]
 categories = ["api-bindings"]
 rust-version = "1.88.0"
 edition = "2021"
-include = ["Cargo.toml", "LICENSE", "README.mkd", "src/**/*.rs"]
+autotests = false
+include = ["Cargo.toml", "LICENSE", "README.mkd", "src/**/*.rs", "tests/**/*.rs", "tests/ordinals.def"]
 
 [features]
 default = ["std"]
@@ -43,3 +44,8 @@ unexpected_cfgs = { level = "warn", check-cfg = [
     'cfg(libloading_docs)',
     'cfg(target_os, values("cygwin"))',
 ] }
+
+[[test]]
+path = "tests/lib.rs"
+name = "integration-tests"
+harness = true

src/test_helpers.rs

@@ -1,6 +1,6 @@
 //! This is a separate file containing helpers for tests of this library. It is built into a
 //! dynamic library by the build.rs script.
-#![crate_type="cdylib"]
+#![crate_type = "cdylib"]
 
 #[no_mangle]
 pub static mut TEST_STATIC_U32: u32 = 0;
@@ -18,7 +18,7 @@ pub struct S {
     a: u64,
     b: u32,
     c: u16,
-    d: u8
+    d: u8,
 }
 
 #[no_mangle]
@@ -35,3 +35,8 @@ pub unsafe extern "C" fn test_get_static_u32() -> u32 {
 pub unsafe extern "C" fn test_check_static_ptr() -> bool {
     TEST_STATIC_PTR == (&mut TEST_STATIC_PTR as *mut *mut _ as *mut _)
 }
+
+#[unsafe(no_mangle)]
+pub extern "C" fn test_ordinals() -> *const std::ffi::c_char {
+    "bunny\0".as_ptr().cast()
+}

tests/functions.rs

@@ -1,10 +1,10 @@
 use libloading::{Library, Symbol};
-use std::os::raw::c_void;
 
 const TARGET_DIR: Option<&'static str> = option_env!("CARGO_TARGET_DIR");
 const TARGET_TMPDIR: Option<&'static str> = option_env!("CARGO_TARGET_TMPDIR");
+const MANIFEST_DIR: &'static str = env!("CARGO_MANIFEST_DIR");
 
-fn lib_path() -> std::path::PathBuf {
+pub fn lib_path() -> std::path::PathBuf {
     [
         TARGET_TMPDIR.unwrap_or(TARGET_DIR.unwrap_or("target")),
         "libtest_helpers.module",
@@ -13,7 +13,7 @@ fn lib_path() -> std::path::PathBuf {
     .collect()
 }
 
-fn make_helpers() {
+pub fn make_helpers() {
     static ONCE: ::std::sync::Once = ::std::sync::Once::new();
     ONCE.call_once(|| {
         if std::env::var_os("PRECOMPILED_TEST_HELPER").is_some() {
@@ -31,6 +31,9 @@ fn make_helpers() {
         } else {
             eprintln!("WARNING: $TARGET NOT SPECIFIED! BUILDING HELPER MODULE FOR NATIVE TARGET.");
         }
+        if cfg!(target_env = "msvc") {
+            cmd.arg(format!("-Clink-arg=/DEF:{MANIFEST_DIR}/tests/ordinals.def"));
+        }
         assert!(cmd
             .status()
             .expect("could not compile the test helpers!")
@@ -194,7 +197,7 @@ fn test_try_into_ptr() {
     unsafe {
         let lib = Library::new(lib_path()).unwrap();
         let f: Symbol<unsafe extern "C" fn(u32) -> u32> = lib.get(b"test_identity_u32\0").unwrap();
-        let ptr: *mut c_void = f.try_as_raw_ptr().unwrap();
+        let ptr: *mut std::ffi::c_void = f.try_as_raw_ptr().unwrap();
         assert!(!ptr.is_null());
         let ptr_casted: extern "C" fn(u32) -> u32 = std::mem::transmute(ptr);
         assert_eq!(42, ptr_casted(42));

tests/lib.rs

@@ -0,0 +1,5 @@
+mod constants;
+mod functions;
+mod library_filename;
+mod markers;
+mod windows;

tests/nagisa32.dll

@@ -0,0 +1,9 @@
+LIBRARY   test_helpers
+EXPORTS
+   test_ordinals   @1 NONAME
+   test_identity_u32 @2
+   test_identity_struct @3
+   test_check_static_ptr @4
+   test_get_static_u32 @5
+   TEST_STATIC_U32 @6
+   TEST_STATIC_PTR @7

tests/nagisa64.dll

@@ -3,24 +3,12 @@ extern crate libloading;
 use libloading::os::windows::*;
 use std::ffi::CStr;
 use std::os::raw::c_void;
-// The ordinal DLL contains exactly one function (other than DllMain, that is) with ordinal number
-// 1. This function has the sugnature `fn() -> *const c_char` and returns a string "bunny\0" (in
-// reference to WindowsBunny).
-//
-// Both x86_64 and x86 versions of the .dll are functionally the same. Ideally we would compile the
-// dlls with well known ordinals from our own testing helpers library, but rustc does not allow
-// specifying a custom .def file (https://github.com/rust-lang/rust/issues/35089)
-//
-// The DLLs were kindly compiled by WindowsBunny (aka. @retep998).
 
-#[cfg(target_arch = "x86")]
-fn load_ordinal_lib() -> Library {
-    unsafe { Library::new("tests/nagisa32.dll").expect("nagisa32.dll") }
-}
-
-#[cfg(target_arch = "x86_64")]
+#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
 fn load_ordinal_lib() -> Library {
-    unsafe { Library::new("tests/nagisa64.dll").expect("nagisa64.dll") }
+    let path = super::functions::lib_path();
+    super::functions::make_helpers();
+    unsafe { Library::new(path.display().to_string()).expect("Windows test dll not found") }
 }
 
 #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
@@ -49,7 +37,8 @@ fn test_try_into_ptr() {
 fn test_ordinal_missing_fails() {
     let lib = load_ordinal_lib();
     unsafe {
-        let r: Result<Symbol<unsafe fn() -> *const i8>, _> = lib.get_ordinal(2);
+        // there are a few other symbols in the test DLL
+        let r: Result<Symbol<unsafe fn() -> *const i8>, _> = lib.get_ordinal(8);
         r.err().unwrap();
         let r: Result<Symbol<unsafe fn() -> *const i8>, _> = lib.get_ordinal(!0);
         r.err().unwrap();

tests/ordinals.def

@@ -0,0 +1,9 @@
+[package]
+name = "windows_test_dll"
+version = "0.1.0"
+edition = "2024"
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]

tests/windows.rs

@@ -0,0 +1,7 @@
+#![crate_type = "cdylib"]
+use std::ffi::c_char;
+
+#[unsafe(no_mangle)]
+pub extern "C" fn test() -> *const c_char {
+    "bunny\0".as_ptr().cast()
+}