assert.h: full impl

include/assert.h

@@ -0,0 +1,13 @@
+#ifndef _ASSERT_H
+#define _ASSERT_H 1
+
+#define assert(x) \
+    do { \
+        if (!(x)) { \
+            __assert_fail(__FILE__, __LINE__, #x); \
+        } \
+    } while(0)
+
+extern _Noreturn void __assert_fail(const char *file, int line, const char *message);
+
+#endif

src/header/mod.rs

@@ -16,7 +16,7 @@ pub mod unistd;
 Impl    Check   Name
 MAYBE           aio.h - asynchronous input and output
 OSSUP           arpa/inet.h - definitions for internet operations
------           assert.h - verify program assertion
++++++           assert.h - verify program assertion
 -----           complex.h - complex arithmetic
 -----           cpio.h - cpio archive values
 -----           ctype.h - character types

src/lib.rs

@@ -12,13 +12,14 @@
 #![allow(internal_features)]
 #![no_std]
 
-use core::ffi::{c_char, c_int};
+use core::ffi::{c_char, c_int, CStr};
 
 use alloc::{ffi::CString, vec::Vec};
 use header::unistd::environ;
+use util::Nullable;
 use yggdrasil_rt::process::{ExitCode, ProgramArgumentInner};
 
-use crate::header::stdio;
+use crate::header::stdio::{self, stderr};
 
 extern crate alloc;
 extern crate yggdrasil_rt;
@@ -60,3 +61,21 @@ fn panic_handler(pi: &core::panic::PanicInfo) -> ! {
     yggdrasil_rt::debug_trace!("--- END PANIC ---");
     process::exit(ExitCode::Exited(1));
 }
+
+#[no_mangle]
+unsafe extern "C" fn __assert_fail(file: *const c_char, line: c_int, expr: *const c_char) -> ! {
+    use core::fmt::Write;
+
+    let err = stderr.as_mut().unwrap();
+
+    file.ensure();
+    expr.ensure();
+
+    let file = CStr::from_ptr(file).to_str().unwrap();
+    let expr = CStr::from_ptr(expr).to_str().unwrap();
+
+    // These should not be NULL, but check nevertheless
+    writeln!(err, "Assertion failed: {:?} at {}:{}", expr, file, line);
+
+    panic!("TODO: abort()");
+}