Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/proc-macro-srv/src/dylib.rs')
| -rw-r--r-- | crates/proc-macro-srv/src/dylib.rs | 54 |
1 files changed, 40 insertions, 14 deletions
diff --git a/crates/proc-macro-srv/src/dylib.rs b/crates/proc-macro-srv/src/dylib.rs index cbf7a277bf..c49159df99 100644 --- a/crates/proc-macro-srv/src/dylib.rs +++ b/crates/proc-macro-srv/src/dylib.rs @@ -9,7 +9,7 @@ use libloading::Library; use object::Object; use paths::{Utf8Path, Utf8PathBuf}; -use crate::{proc_macros::ProcMacros, server_impl::TopSubtree, ProcMacroKind, ProcMacroSrvSpan}; +use crate::{ProcMacroKind, ProcMacroSrvSpan, proc_macros::ProcMacros, server_impl::TopSubtree}; /// Loads dynamic library in platform dependent manner. /// @@ -21,13 +21,32 @@ use crate::{proc_macros::ProcMacros, server_impl::TopSubtree, ProcMacroKind, Pro /// [here](https://github.com/fedochet/rust-proc-macro-panic-inside-panic-expample/issues/1) /// /// It seems that on Windows that behaviour is default, so we do nothing in that case. +/// +/// # Safety +/// +/// The caller is responsible for ensuring that the path is valid proc-macro library #[cfg(windows)] -fn load_library(file: &Utf8Path) -> Result<Library, libloading::Error> { +unsafe fn load_library(file: &Utf8Path) -> Result<Library, libloading::Error> { + // SAFETY: The caller is responsible for ensuring that the path is valid proc-macro library unsafe { Library::new(file) } } +/// Loads dynamic library in platform dependent manner. +/// +/// For unix, you have to use RTLD_DEEPBIND flag to escape problems described +/// [here](https://github.com/fedochet/rust-proc-macro-panic-inside-panic-expample) +/// and [here](https://github.com/rust-lang/rust/issues/60593). +/// +/// Usage of RTLD_DEEPBIND +/// [here](https://github.com/fedochet/rust-proc-macro-panic-inside-panic-expample/issues/1) +/// +/// It seems that on Windows that behaviour is default, so we do nothing in that case. +/// +/// # Safety +/// +/// The caller is responsible for ensuring that the path is valid proc-macro library #[cfg(unix)] -fn load_library(file: &Utf8Path) -> Result<Library, libloading::Error> { +unsafe fn load_library(file: &Utf8Path) -> Result<Library, libloading::Error> { // not defined by POSIX, different values on mips vs other targets #[cfg(target_env = "gnu")] use libc::RTLD_DEEPBIND; @@ -39,6 +58,7 @@ fn load_library(file: &Utf8Path) -> Result<Library, libloading::Error> { #[cfg(not(target_env = "gnu"))] const RTLD_DEEPBIND: std::os::raw::c_int = 0x0; + // SAFETY: The caller is responsible for ensuring that the path is valid proc-macro library unsafe { UnixLibrary::open(Some(file), RTLD_NOW | RTLD_DEEPBIND).map(|lib| lib.into()) } } @@ -84,26 +104,32 @@ struct ProcMacroLibrary { impl ProcMacroLibrary { fn open(path: &Utf8Path) -> Result<Self, LoadProcMacroDylibError> { let file = fs::File::open(path)?; + #[allow(clippy::undocumented_unsafe_blocks)] // FIXME let file = unsafe { memmap2::Mmap::map(&file) }?; let obj = object::File::parse(&*file) .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?; let version_info = version::read_dylib_info(&obj)?; + if version_info.version_string != crate::RUSTC_VERSION_STRING { + return Err(LoadProcMacroDylibError::AbiMismatch(version_info.version_string)); + } + let symbol_name = find_registrar_symbol(&obj).map_err(invalid_data_err)?.ok_or_else(|| { invalid_data_err(format!("Cannot find registrar symbol in file {path}")) })?; - let lib = load_library(path).map_err(invalid_data_err)?; - let proc_macros = unsafe { - // SAFETY: We extend the lifetime here to avoid referential borrow problems - // We never reveal proc_macros to the outside and drop it before _lib - std::mem::transmute::<&ProcMacros, &'static ProcMacros>(ProcMacros::from_lib( - &lib, - symbol_name, - &version_info.version_string, - )?) - }; - Ok(ProcMacroLibrary { _lib: lib, proc_macros }) + // SAFETY: We have verified the validity of the dylib as a proc-macro library + let lib = unsafe { load_library(path) }.map_err(invalid_data_err)?; + // SAFETY: We have verified the validity of the dylib as a proc-macro library + // The 'static lifetime is a lie, it's actually the lifetime of the library but unavoidable + // due to self-referentiality + // But we make sure that we do not drop it before the symbol is dropped + let proc_macros = + unsafe { lib.get::<&'static &'static ProcMacros>(symbol_name.as_bytes()) }; + match proc_macros { + Ok(proc_macros) => Ok(ProcMacroLibrary { proc_macros: *proc_macros, _lib: lib }), + Err(e) => Err(e.into()), + } } } |