From 462ac2d92c80aa10ae378c0f73057dfc8e4754fd Mon Sep 17 00:00:00 2001 From: Ben Kimock Date: Sat, 18 May 2024 20:14:40 -0400 Subject: [PATCH] cfg out the extern crate libc on Windows --- src/beneath-std.md | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/src/beneath-std.md b/src/beneath-std.md index 02a02bd7..da2cc500 100644 --- a/src/beneath-std.md +++ b/src/beneath-std.md @@ -19,7 +19,10 @@ Note that the default features have been disabled. This is a critical step - disabled.** Alternatively, we can use the unstable `rustc_private` private feature together -with an `extern crate libc;` declaration as shown in the examples below. +with an `extern crate libc;` declaration as shown in the examples below. Note that +windows-msvc targets do not require a libc, and correspondingly there is no `libc` +crate in their sysroot. We do not need the `extern crate libc;` below, and having it +on a windows-msvc target would be a compile error. ## Writing an executable without `std` @@ -39,11 +42,12 @@ in the same format as C (aside from the exact integer types being used): #![allow(internal_features)] #![no_std] -// Necessary for `panic = "unwind"` builds on some platforms. +// Necessary for `panic = "unwind"` builds on cfg(unix) platforms. #![feature(panic_unwind)] extern crate unwind; // Pull in the system libc library for what crt0.o likely requires. +#[cfg(not(windows))] extern crate libc; use core::panic::PanicInfo; @@ -73,11 +77,12 @@ compiler's name mangling too: #![no_std] #![no_main] -// Necessary for `panic = "unwind"` builds on some platforms. +// Necessary for `panic = "unwind"` builds on cfg(unix) platforms. #![feature(panic_unwind)] extern crate unwind; // Pull in the system libc library for what crt0.o likely requires. +#[cfg(not(windows))] extern crate libc; use core::ffi::{c_char, c_int};