rework to use traits instead of file names.

Author: AlexanderSchuetz97

.github/workflows/libloading.yml

@@ -15,7 +15,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        rust_toolchain: [nightly, stable, 1.71.0]
+        rust_toolchain: [nightly, stable, 1.81.0]
         os: [ubuntu-latest, windows-latest, macOS-latest]
     timeout-minutes: 20
     steps:
@@ -24,10 +24,12 @@ jobs:
       - run: rustup default ${{ matrix.rust_toolchain }}
       - run: rustup component add clippy
       - run: cargo update -p libc --precise 0.2.155
-        if: ${{ matrix.rust_toolchain == '1.71.0' }}
+        if: ${{ matrix.rust_toolchain == '1.81.0' }}
       - run: cargo clippy
       - run: cargo test -- --nocapture
       - run: cargo test --release -- --nocapture
+      - run: cargo test --no-default-features -- --nocapture
+      - run: cargo test --release --no-default-features -- --nocapture
       - run: cargo rustdoc -Zunstable-options --config 'build.rustdocflags=["--cfg", "libloading_docs", "-D", "rustdoc::broken_intra_doc_links"]'
         if: ${{ matrix.rust_toolchain == 'nightly' }}
         # pwsh.exe drops quotes kekw. https://stackoverflow.com/a/59036879

Cargo.toml

@@ -12,7 +12,7 @@ readme = "README.mkd"
 description = "Bindings around the platform's dynamic library loading primitives with greatly improved memory safety."
 keywords = ["dlopen", "load", "shared", "dylib"]
 categories = ["api-bindings"]
-rust-version = "1.71.0"
+rust-version = "1.81.0"
 edition = "2015"
 
 [features]

src/as_filename.rs

@@ -0,0 +1,356 @@
+use alloc::ffi::CString;
+use alloc::string::String;
+use alloc::vec::Vec;
+use core::ffi::{c_char, CStr};
+use util::cstr_cow_from_bytes;
+use Error;
+
+mod private {
+
+    pub trait AsFilenameSeal {
+        #[allow(unused)] //Posix doesnt use this
+        fn windows_filename<R>(
+            &self,
+            function: impl FnOnce(*const u16) -> Result<R, crate::Error>,
+        ) -> Result<R, crate::Error>;
+
+        #[allow(unused)] //Windows doesnt use this
+        fn posix_filename<R>(
+            &self,
+            function: impl FnOnce(*const core::ffi::c_char) -> Result<R, crate::Error>,
+        ) -> Result<R, crate::Error>;
+    }
+}
+
+/// This trait is implemented on all types where libloading can derrive a filename from.
+/// It is sealed and cannot be implemented by a user of libloading.
+///
+/// This trait is implemented for the following common types:
+/// - String &String &str
+/// - CString &CString &CStr
+/// - OsString &OsString &OsStr
+/// - PathBuf &PathBuf &Path
+/// - &[u8] assumes utf8 data!
+/// - &[u16] assumes utf16-ne data!
+///
+pub trait AsFilename: private::AsFilenameSeal {}
+
+impl<T> AsFilename for T where T: private::AsFilenameSeal {}
+
+impl private::AsFilenameSeal for &str {
+    fn windows_filename<R>(
+        &self,
+        function: impl FnOnce(*const u16) -> Result<R, Error>,
+    ) -> Result<R, Error> {
+        let mut utf16: Vec<u16> = self.encode_utf16().collect();
+        if utf16.last() != Some(&0) {
+            utf16.push(0);
+        };
+        function(utf16.as_ptr())
+    }
+
+    fn posix_filename<R>(
+        &self,
+        function: impl FnOnce(*const c_char) -> Result<R, Error>,
+    ) -> Result<R, Error> {
+        let cow = cstr_cow_from_bytes(self.as_bytes())?;
+        function(cow.as_ptr())
+    }
+}
+
+impl private::AsFilenameSeal for &String {
+    fn windows_filename<R>(
+        &self,
+        function: impl FnOnce(*const u16) -> Result<R, Error>,
+    ) -> Result<R, Error> {
+        self.as_str().windows_filename(function)
+    }
+
+    fn posix_filename<R>(
+        &self,
+        function: impl FnOnce(*const c_char) -> Result<R, Error>,
+    ) -> Result<R, Error> {
+        let cow = cstr_cow_from_bytes(self.as_bytes())?;
+        function(cow.as_ptr())
+    }
+}
+
+impl private::AsFilenameSeal for String {
+    fn windows_filename<R>(
+        &self,
+        function: impl FnOnce(*const u16) -> Result<R, Error>,
+    ) -> Result<R, Error> {
+        self.as_str().windows_filename(function)
+    }
+
+    fn posix_filename<R>(
+        &self,
+        function: impl FnOnce(*const c_char) -> Result<R, Error>,
+    ) -> Result<R, Error> {
+        let cow = cstr_cow_from_bytes(self.as_bytes())?;
+        function(cow.as_ptr())
+    }
+}
+
+impl private::AsFilenameSeal for &CStr {
+    fn windows_filename<R>(
+        &self,
+        function: impl FnOnce(*const u16) -> Result<R, Error>,
+    ) -> Result<R, Error> {
+        //We assume cstr is utf-8 here, if it's something bespoke like CESU-8 (thanks java) then yeah... no.
+        let utf8 = self.to_str()?;
+        utf8.windows_filename(function)
+    }
+
+    fn posix_filename<R>(
+        &self,
+        function: impl FnOnce(*const c_char) -> Result<R, Error>,
+    ) -> Result<R, Error> {
+        function(self.as_ptr())
+    }
+}
+
+impl private::AsFilenameSeal for &CString {
+    fn windows_filename<R>(
+        &self,
+        function: impl FnOnce(*const u16) -> Result<R, Error>,
+    ) -> Result<R, Error> {
+        self.as_c_str().windows_filename(function)
+    }
+
+    fn posix_filename<R>(
+        &self,
+        function: impl FnOnce(*const c_char) -> Result<R, Error>,
+    ) -> Result<R, Error> {
+        self.as_c_str().posix_filename(function)
+    }
+}
+
+impl private::AsFilenameSeal for CString {
+    fn windows_filename<R>(
+        &self,
+        function: impl FnOnce(*const u16) -> Result<R, Error>,
+    ) -> Result<R, Error> {
+        self.as_c_str().windows_filename(function)
+    }
+
+    fn posix_filename<R>(
+        &self,
+        function: impl FnOnce(*const c_char) -> Result<R, Error>,
+    ) -> Result<R, Error> {
+        self.as_c_str().posix_filename(function)
+    }
+}
+
+/// This implementation assumes that a slice always contains utf-8 bytes.
+/// (which is likely the most common case if the slice originated in rust)
+impl private::AsFilenameSeal for &[u8] {
+    fn windows_filename<R>(
+        &self,
+        function: impl FnOnce(*const u16) -> Result<R, Error>,
+    ) -> Result<R, Error> {
+        let utf8 = core::str::from_utf8(self)?;
+        utf8.windows_filename(function)
+    }
+
+    fn posix_filename<R>(
+        &self,
+        function: impl FnOnce(*const c_char) -> Result<R, Error>,
+    ) -> Result<R, Error> {
+        let utf8 = core::str::from_utf8(self)?;
+        utf8.posix_filename(function)
+    }
+}
+
+impl<const N: usize> private::AsFilenameSeal for [u8; N] {
+    fn windows_filename<R>(
+        &self,
+        function: impl FnOnce(*const u16) -> Result<R, Error>,
+    ) -> Result<R, Error> {
+        self.as_slice().windows_filename(function)
+    }
+
+    fn posix_filename<R>(
+        &self,
+        function: impl FnOnce(*const c_char) -> Result<R, Error>,
+    ) -> Result<R, Error> {
+        self.as_slice().posix_filename(function)
+    }
+}
+
+impl<const N: usize> private::AsFilenameSeal for &[u8; N] {
+    fn windows_filename<R>(
+        &self,
+        function: impl FnOnce(*const u16) -> Result<R, Error>,
+    ) -> Result<R, Error> {
+        self.as_slice().windows_filename(function)
+    }
+
+    fn posix_filename<R>(
+        &self,
+        function: impl FnOnce(*const c_char) -> Result<R, Error>,
+    ) -> Result<R, Error> {
+        self.as_slice().posix_filename(function)
+    }
+}
+
+/// This implementation assumes that the slice contains utf-16 in native endian.
+/// Sidenote: For windows this is always utf-16-le because the last big endian Windows system was the xbox 360 that rust doesn't support.
+/// For linux this is highly likely to also be utf-16-le because big endian is only used in some old mips routers or some IBM hardware.
+impl private::AsFilenameSeal for &[u16] {
+    fn windows_filename<R>(
+        &self,
+        function: impl FnOnce(*const u16) -> Result<R, Error>,
+    ) -> Result<R, Error> {
+        //Check that we have valid utf-16
+        for c in core::char::decode_utf16(self.iter().copied()) {
+            let _ = c?;
+        }
+
+        if self.last() != Some(&0) {
+            let mut copy = self.to_vec();
+            copy.push(0);
+            return function(copy.as_ptr());
+        }
+
+        function(self.as_ptr())
+    }
+
+    fn posix_filename<R>(
+        &self,
+        function: impl FnOnce(*const c_char) -> Result<R, Error>,
+    ) -> Result<R, Error> {
+        let utf8 = String::from_utf16(self)?;
+        utf8.posix_filename(function)
+    }
+}
+
+#[cfg(feature = "std")]
+#[cfg(any(windows, unix))]
+mod std {
+    use as_filename::private;
+    use core::ffi::c_char;
+    use std::ffi::{OsStr, OsString};
+    use Error;
+
+    impl private::AsFilenameSeal for &OsStr {
+        #[cfg(unix)]
+        fn windows_filename<R>(
+            &self,
+            _function: impl FnOnce(*const u16) -> Result<R, Error>,
+        ) -> Result<R, Error> {
+            panic!("windows_filename() not implemented for OsStr on posix platform");
+        }
+
+        #[cfg(windows)]
+        fn windows_filename<R>(
+            &self,
+            function: impl FnOnce(*const u16) -> Result<R, Error>,
+        ) -> Result<R, Error> {
+            let mut utf16: alloc::vec::Vec<u16> =
+                std::os::windows::ffi::OsStrExt::encode_wide(*self).collect();
+            if utf16.last() != Some(&0) {
+                utf16.push(0);
+            };
+            function(utf16.as_ptr())
+        }
+
+        #[cfg(unix)]
+        fn posix_filename<R>(
+            &self,
+            function: impl FnOnce(*const c_char) -> Result<R, Error>,
+        ) -> Result<R, Error> {
+            let cow =
+                crate::util::cstr_cow_from_bytes(std::os::unix::ffi::OsStrExt::as_bytes(*self))?;
+            function(cow.as_ptr())
+        }
+
+        #[cfg(windows)]
+        fn posix_filename<R>(
+            &self,
+            _function: impl FnOnce(*const c_char) -> Result<R, Error>,
+        ) -> Result<R, Error> {
+            panic!("posix_filename() not implemented for OsStr on windows")
+        }
+    }
+
+    impl private::AsFilenameSeal for &OsString {
+        fn windows_filename<R>(
+            &self,
+            function: impl FnOnce(*const u16) -> Result<R, Error>,
+        ) -> Result<R, Error> {
+            self.as_os_str().windows_filename(function)
+        }
+
+        fn posix_filename<R>(
+            &self,
+            function: impl FnOnce(*const c_char) -> Result<R, Error>,
+        ) -> Result<R, Error> {
+            self.as_os_str().posix_filename(function)
+        }
+    }
+
+    impl private::AsFilenameSeal for OsString {
+        fn windows_filename<R>(
+            &self,
+            function: impl FnOnce(*const u16) -> Result<R, Error>,
+        ) -> Result<R, Error> {
+            self.as_os_str().windows_filename(function)
+        }
+
+        fn posix_filename<R>(
+            &self,
+            function: impl FnOnce(*const c_char) -> Result<R, Error>,
+        ) -> Result<R, Error> {
+            self.as_os_str().posix_filename(function)
+        }
+    }
+
+    impl private::AsFilenameSeal for std::path::PathBuf {
+        fn windows_filename<R>(
+            &self,
+            function: impl FnOnce(*const u16) -> Result<R, Error>,
+        ) -> Result<R, Error> {
+            self.as_os_str().windows_filename(function)
+        }
+
+        fn posix_filename<R>(
+            &self,
+            function: impl FnOnce(*const c_char) -> Result<R, Error>,
+        ) -> Result<R, Error> {
+            self.as_os_str().posix_filename(function)
+        }
+    }
+
+    impl private::AsFilenameSeal for &std::path::PathBuf {
+        fn windows_filename<R>(
+            &self,
+            function: impl FnOnce(*const u16) -> Result<R, Error>,
+        ) -> Result<R, Error> {
+            self.as_os_str().windows_filename(function)
+        }
+
+        fn posix_filename<R>(
+            &self,
+            function: impl FnOnce(*const c_char) -> Result<R, Error>,
+        ) -> Result<R, Error> {
+            self.as_os_str().posix_filename(function)
+        }
+    }
+
+    impl private::AsFilenameSeal for &std::path::Path {
+        fn windows_filename<R>(
+            &self,
+            function: impl FnOnce(*const u16) -> Result<R, Error>,
+        ) -> Result<R, Error> {
+            self.as_os_str().windows_filename(function)
+        }
+
+        fn posix_filename<R>(
+            &self,
+            function: impl FnOnce(*const c_char) -> Result<R, Error>,
+        ) -> Result<R, Error> {
+            self.as_os_str().posix_filename(function)
+        }
+    }
+}