//! `__attribute__((constructor))` in C/C++) for Linux, OSX, and Windows via
//! the `#[ctor]` and `#[dtor]` macros.
//!
-//! This library works and has been tested for Linux, OSX and Windows. This
-//! library will also work as expected in both `bin` and `cdylib` outputs,
-//! ie: the `ctor` and `dtor` will run at executable or library
+//! This library works and is regularly tested on Linux, OSX and Windows, with both `+crt-static` and `-crt-static`.
+//! Other platforms are supported but not tested as part of the automatic builds. This library will also work as expected in both
+//! `bin` and `cdylib` outputs, ie: the `ctor` and `dtor` will run at executable or library
//! startup/shutdown respectively.
//!
//! This library currently requires Rust > `1.31.0` at a minimum for the
// https://github.com/Alexpux/mingw-w64/blob/d0d7f784833bbb0b2d279310ddc6afb52fe47a46/mingw-w64-crt/crt/crtdll.c
+// In addition, OSX has removed support for section-based shutdown hooks after
+// warning about it for a number of years:
+
+// https://reviews.llvm.org/D45578
+
extern crate proc_macro;
extern crate syn;
#[macro_use]
extern crate quote;
-use proc_macro::TokenStream;
+use proc_macro::{TokenStream};
+
+/// Attributes required to mark a function as a constructor. This may be exposed in the future if we determine
+/// it to be stable.
+#[doc(hidden)]
+macro_rules! ctor_attributes {
+ () => {
+ quote!(
+ #[cfg_attr(any(target_os = "linux", target_os = "android"), link_section = ".init_array")]
+ #[cfg_attr(target_os = "freebsd", link_section = ".init_array")]
+ #[cfg_attr(target_os = "netbsd", link_section = ".init_array")]
+ #[cfg_attr(target_os = "openbsd", link_section = ".init_array")]
+ #[cfg_attr(target_os = "dragonfly", link_section = ".init_array")]
+ #[cfg_attr(target_os = "illumos", link_section = ".init_array")]
+ #[cfg_attr(target_os = "haiku", link_section = ".init_array")]
+ #[cfg_attr(any(target_os = "macos", target_os = "ios"), link_section = "__DATA,__mod_init_func")]
+ #[cfg_attr(windows, link_section = ".CRT$XCU")]
+ )
+ };
+}
/// Marks a function or static variable as a library/executable constructor.
/// This uses OS-specific linker sections to call a specific function at
///
/// # Examples
///
-/// Print a startup message:
+/// Print a startup message (using `libc_print` for safety):
///
/// ```rust
/// # extern crate ctor;
/// # use ctor::*;
+/// use libc_print::std_name::println;
+///
/// #[ctor]
/// fn foo() {
/// println!("Hello, world!");
syn::parse_str::<syn::Ident>(format!("{}___rust_ctor___ctor", ident).as_ref())
.expect("Unable to create identifier");
+ let tokens = ctor_attributes!();
let output = quote!(
#[cfg(not(any(target_os = "linux", target_os = "android", target_os = "freebsd", target_os = "netbsd", target_os = "openbsd", target_os = "dragonfly", target_os = "illumos", target_os = "haiku", target_os = "macos", target_os = "ios", windows)))]
compile_error!("#[ctor] is not supported on the current target");
#[used]
#[allow(non_upper_case_globals)]
#[doc(hidden)]
- #[cfg_attr(any(target_os = "linux", target_os = "android"), link_section = ".init_array")]
- #[cfg_attr(target_os = "freebsd", link_section = ".init_array")]
- #[cfg_attr(target_os = "netbsd", link_section = ".init_array")]
- #[cfg_attr(target_os = "openbsd", link_section = ".init_array")]
- #[cfg_attr(target_os = "dragonfly", link_section = ".init_array")]
- #[cfg_attr(target_os = "illumos", link_section = ".init_array")]
- #[cfg_attr(target_os = "haiku", link_section = ".init_array")]
- #[cfg_attr(any(target_os = "macos", target_os = "ios"), link_section = "__DATA,__mod_init_func")]
- #[cfg_attr(windows, link_section = ".CRT$XCU")]
+ #tokens
static #ctor_ident
:
unsafe extern "C" fn() =
..
} = var;
- if let Some(_) = mutability {
+ if mutability.is_some() {
panic!("#[ctor]-annotated static objects must not be mutable");
}
syn::parse_str::<syn::Ident>(format!("{}___rust_ctor___storage", ident).as_ref())
.expect("Unable to create identifier");
+ let tokens = ctor_attributes!();
let output = quote!(
#[cfg(not(any(target_os = "linux", target_os = "android", target_os = "freebsd", target_os = "netbsd", target_os = "openbsd", target_os = "dragonfly", target_os = "illumos", target_os = "haiku", target_os = "macos", target_os = "ios", windows)))]
compile_error!("#[ctor] is not supported on the current target");
#[used]
#[allow(non_upper_case_globals)]
- #[cfg_attr(any(target_os = "linux", target_os = "android"), link_section = ".init_array")]
- #[cfg_attr(target_os = "freebsd", link_section = ".init_array")]
- #[cfg_attr(target_os = "netbsd", link_section = ".init_array")]
- #[cfg_attr(target_os = "openbsd", link_section = ".init_array")]
- #[cfg_attr(target_os = "dragonfly", link_section = ".init_array")]
- #[cfg_attr(target_os = "illumos", link_section = ".init_array")]
- #[cfg_attr(target_os = "haiku", link_section = ".init_array")]
- #[cfg_attr(any(target_os = "macos", target_os = "ios"), link_section = "__DATA,__mod_init_func")]
- #[cfg_attr(windows, link_section = ".CRT$XCU")]
+ #tokens
static #ctor_ident
:
unsafe extern "C" fn() = {
let dtor_ident = syn::parse_str::<syn::Ident>(format!("{}___rust_dtor___dtor", ident).as_ref())
.expect("Unable to create identifier");
+ let tokens = ctor_attributes!();
let output = quote!(
#[cfg(not(any(target_os = "linux", target_os = "android", target_os = "freebsd", target_os = "netbsd", target_os = "openbsd", target_os = "dragonfly", target_os = "illumos", target_os = "haiku", target_os = "macos", target_os = "ios", windows)))]
compile_error!("#[dtor] is not supported on the current target");
#(#attrs)*
#vis #unsafety extern #abi #constness fn #ident() #block
- // Targets that use `atexit`.
- #[cfg(not(any(
- target_os = "macos",
- target_os = "ios",
- )))]
mod #mod_ident {
use super::#ident;
- // Avoid a dep on libc by linking directly
- extern "C" {
- fn atexit(cb: unsafe extern fn());
+ // Note that we avoid a dep on the libc crate by linking directly to atexit functions
+
+ #[cfg(not(any(target_os = "macos", target_os = "ios")))]
+ #[inline(always)]
+ unsafe fn do_atexit(cb: unsafe extern fn()) {
+ extern "C" {
+ fn atexit(cb: unsafe extern fn());
+ }
+ atexit(cb);
+ }
+
+ // For platforms that have __cxa_atexit, we register the dtor as scoped to dso_handle
+ #[cfg(any(target_os = "macos", target_os = "ios"))]
+ #[inline(always)]
+ unsafe fn do_atexit(cb: unsafe extern fn()) {
+ extern "C" {
+ static __dso_handle: *const u8;
+ fn __cxa_atexit(cb: unsafe extern fn(), arg: *const u8, dso_handle: *const u8);
+ }
+ __cxa_atexit(cb, std::ptr::null(), __dso_handle);
}
#[used]
#[allow(non_upper_case_globals)]
- #[cfg_attr(any(target_os = "linux", target_os = "android"), link_section = ".init_array")]
- #[cfg_attr(target_os = "freebsd", link_section = ".init_array")]
- #[cfg_attr(target_os = "netbsd", link_section = ".init_array")]
- #[cfg_attr(target_os = "openbsd", link_section = ".init_array")]
- #[cfg_attr(target_os = "dragonfly", link_section = ".init_array")]
- #[cfg_attr(target_os = "illumos", link_section = ".init_array")]
- #[cfg_attr(target_os = "haiku", link_section = ".init_array")]
- #[cfg_attr(windows, link_section = ".CRT$XCU")]
+ #tokens
static __dtor_export
:
unsafe extern "C" fn() =
unsafe extern "C" fn #dtor_ident() { #ident() };
#[cfg_attr(any(target_os = "linux", target_os = "android"), link_section = ".text.startup")]
unsafe extern fn __dtor_atexit() {
- atexit(#dtor_ident);
+ do_atexit(#dtor_ident);
};
__dtor_atexit
};
}
-
- // Targets that don't rely on `atexit`.
- #[cfg(any(
- target_os = "macos",
- target_os = "ios",
- ))]
- mod #mod_ident {
- use super::#ident;
-
- #[used]
- #[allow(non_upper_case_globals)]
- #[cfg_attr(any(target_os = "macos", target_os = "ios"), link_section = "__DATA,__mod_term_func")]
- static __dtor_export
- :
- unsafe extern "C" fn() =
- {
- unsafe extern fn __dtor() { #ident() };
- __dtor
- };
- }
);
// eprintln!("{}", output);
}
// No parameters allowed
- if sig.inputs.len() > 0 {
+ if !sig.inputs.is_empty() {
panic!("#[{}] methods may not have parameters", typ);
}
projects / rustc.git / blobdiff