diff --git a/library/std/src/sys/windows/compat.rs b/library/std/src/sys/windows/compat.rs index a914a3bcc120b..c55df04200313 100644 --- a/library/std/src/sys/windows/compat.rs +++ b/library/std/src/sys/windows/compat.rs @@ -77,6 +77,10 @@ macro_rules! compat_fn { static INIT_TABLE_ENTRY: unsafe extern "C" fn() = init; unsafe extern "C" fn init() { + PTR = get_f(); + } + + unsafe extern "C" fn get_f() -> Option { // There is no locking here. This code is executed before main() is entered, and // is guaranteed to be single-threaded. // @@ -88,13 +92,13 @@ macro_rules! compat_fn { let symbol_name: *const u8 = concat!(stringify!($symbol), "\0").as_ptr(); let module_handle = $crate::sys::c::GetModuleHandleA(module_name as *const i8); if !module_handle.is_null() { - match $crate::sys::c::GetProcAddress(module_handle, symbol_name as *const i8).addr() { - 0 => {} - n => { - PTR = Some(mem::transmute::(n)); - } + let ptr = $crate::sys::c::GetProcAddress(module_handle, symbol_name as *const i8); + if !ptr.is_null() { + // Transmute to the right function pointer type. + return Some(mem::transmute(ptr)); } } + return None; } #[allow(dead_code)] @@ -105,10 +109,15 @@ macro_rules! compat_fn { #[allow(dead_code)] pub unsafe fn call($($argname: $argtype),*) -> $rettype { if let Some(ptr) = PTR { - ptr($($argname),*) - } else { - $fallback_body + return ptr($($argname),*); + } + if cfg!(miri) { + // Miri does not run `init`, so we just call `get_f` each time. + if let Some(ptr) = get_f() { + return ptr($($argname),*); + } } + $fallback_body } }