diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/changelog.rs | 11 | ||||
| -rw-r--r-- | src/error.rs | 2 | ||||
| -rw-r--r-- | src/os/windows/mod.rs | 39 |
3 files changed, 51 insertions, 1 deletions
diff --git a/src/changelog.rs b/src/changelog.rs index 0ae7323..67f9cb0 100644 --- a/src/changelog.rs +++ b/src/changelog.rs @@ -3,6 +3,17 @@ // TODO: for the next breaking release rename `Error::LoadLibraryW` to `Error::LoadLibraryExW`. // TODO: for the next breaking release use `RTLD_LAZY | RTLD_LOCAL` by default on unix. +/// Release 0.6.7 (2021-01-14) +/// +/// * Added a [`os::windows::Library::open_already_loaded`] to obtain a handle to a library that +/// must already be loaded. There is no portable equivalent for all UNIX targets. Users who do not +/// care about portability across UNIX platforms may use [`os::unix::Library::open`] with +/// `libc::RTLD_NOLOAD`; +/// +/// [`os::windows::Library::open_already_loaded`]: crate::os::windows::Library::open_already_loaded +/// [`os::unix::Library::open`]: crate::os::unix::Library::open +pub mod r0_6_7 {} + /// Release 0.6.6 (2020-12-03) /// /// * Fix a double-release of resources when [`Library::close`] or [`os::windows::Library::close`] diff --git a/src/error.rs b/src/error.rs index 6ba5367..e1c465e 100644 --- a/src/error.rs +++ b/src/error.rs @@ -55,7 +55,7 @@ pub enum Error { /// The source error. source: WindowsError }, - /// The `LoadLibraryW` call failed and system did not report an error. + /// The `GetModuleHandleExW` call failed and system did not report an error. GetModuleHandleExWUnknown, /// The `GetProcAddress` call failed. GetProcAddress { diff --git a/src/os/windows/mod.rs b/src/os/windows/mod.rs index da1b5c9..f1298f6 100644 --- a/src/os/windows/mod.rs +++ b/src/os/windows/mod.rs @@ -119,6 +119,45 @@ impl Library { } } + /// Load a module that is already loaded by the program. + /// + /// This function returns a `Library` corresponding to a module with the given name that is + /// already mapped into the address space of the process. If the module isn't found an error is + /// returned. + /// + /// If the `filename` does not include a full path and there are multiple different loaded + /// modules corresponding to the `filename`, it is impossible to predict which module handle + /// will be returned. For more information refer to [MSDN]. + /// + /// If the `filename` specifies a library filename without path and with extension omitted, + /// `.dll` extension is implicitly added. This behaviour may be suppressed by appending a + /// trailing `.` to the `filename`. + /// + /// This is equivalent to `GetModuleHandleExW(0, filename, _)`. + /// + /// [MSDN]: https://docs.microsoft.com/en-us/windows/win32/api/libloaderapi/nf-libloaderapi-getmodulehandleexw + pub fn open_already_loaded<P: AsRef<OsStr>>(filename: P) -> Result<Library, crate::Error> { + let wide_filename: Vec<u16> = filename.as_ref().encode_wide().chain(Some(0)).collect(); + + let ret = unsafe { + let mut handle: HMODULE = std::ptr::null_mut(); + with_get_last_error(|source| crate::Error::GetModuleHandleExW { source }, || { + // Make sure no winapi calls as a result of drop happen inside this closure, because + // otherwise that might change the return value of the GetLastError. + let result = libloaderapi::GetModuleHandleExW(0, wide_filename.as_ptr(), &mut handle); + if result == 0 { + None + } else { + Some(Library(handle)) + } + }).map_err(|e| e.unwrap_or(crate::Error::GetModuleHandleExWUnknown)) + }; + + drop(wide_filename); // Drop wide_filename here to ensure it doesn’t get moved and dropped + // inside the closure by mistake. See comment inside the closure. + ret + } + /// Find and load a module, additionally adjusting behaviour with flags. /// /// See [`Library::new`] for documentation on handling of the `filename` argument. See the |