Implement psignal and psiginfo.

src/header/signal/mod.rs

@@ -5,14 +5,15 @@ use core::{mem, ptr};
 use cbitset::BitSet;
 
 use crate::{
-    error::{self, Errno, ResultExt},
+    error::{Errno, ResultExt},
+    c_str::CStr,
     header::{errno, time::timespec},
     platform::{self, types::*, Pal, PalSignal, Sys},
 };
 
 pub use self::sys::*;
 
-use super::errno::EFAULT;
+use super::{errno::EFAULT, unistd};
 
 #[cfg(target_os = "linux")]
 #[path = "linux.rs"]
@@ -54,6 +55,7 @@ pub struct sigaltstack {
     pub ss_size: size_t,
 }
 
+// FIXME: This struct is wrong on Linux
 #[repr(C)]
 #[derive(Clone, Copy)]
 pub struct siginfo {
@@ -395,7 +397,7 @@ pub unsafe extern "C" fn sigwaitinfo(set: *const sigset_t, sig: *mut siginfo_t)
     sigtimedwait(set, sig, core::ptr::null())
 }
 
-pub const _signal_strings: [&str; 32] = [
+pub(crate) const SIGNAL_STRINGS: [&str; 32] = [
     "Unknown signal\0",
     "Hangup\0",
     "Interrupt\0",
@@ -429,3 +431,55 @@ pub const _signal_strings: [&str; 32] = [
     "Power failure\0",
     "Bad system call\0",
 ];
+#[no_mangle]
+pub unsafe extern "C" fn psignal(sig: c_int, prefix: *const c_char) {
+    let c_description = usize::try_from(sig)
+        .ok()
+        .and_then(|idx| SIGNAL_STRINGS.get(idx))
+        .unwrap_or(&SIGNAL_STRINGS[0]);
+    let description = &c_description[..c_description.len() - 1];
+    let prefix = CStr::from_ptr(prefix).to_string_lossy();
+    // TODO: stack vec or print directly?
+    let string = alloc::format!("{prefix}:{description}\n");
+    // TODO: better internal libc API?
+    let _ = unistd::write(
+        unistd::STDERR_FILENO,
+        string.as_bytes().as_ptr().cast(),
+        string.as_bytes().len(),
+    );
+}
+#[no_mangle]
+pub unsafe extern "C" fn psiginfo(info: *const siginfo_t, prefix: *const c_char) {
+    let siginfo_t {
+        si_code,
+        si_signo,
+        si_pid,
+        si_uid,
+        si_errno,
+        si_addr,
+        si_status,
+        si_value,
+    } = &*info;
+    let sival_ptr = si_value.sival_ptr;
+    let prefix = CStr::from_ptr(prefix).to_string_lossy();
+    // TODO: stack vec or print directly?
+    let string = alloc::format!(
+        "{prefix}:siginfo_t {{
+    si_code: {si_code}
+    si_signo: {si_signo}
+    si_pid: {si_pid}
+    si_uid: {si_uid}
+    si_errno: {si_errno}
+    si_addr: {si_addr:p}
+    si_status: {si_status}
+    si_value: {sival_ptr:p}
+}}
+"
+    );
+    // TODO: better internal libc API?
+    let _ = unistd::write(
+        unistd::STDERR_FILENO,
+        string.as_bytes().as_ptr().cast(),
+        string.as_bytes().len(),
+    );
+}

src/header/string/mod.rs

@@ -353,9 +353,9 @@ pub unsafe extern "C" fn strrchr(s: *const c_char, c: c_int) -> *mut c_char {
 
 #[no_mangle]
 pub unsafe extern "C" fn strsignal(sig: c_int) -> *mut c_char {
-    signal::_signal_strings
+    signal::SIGNAL_STRINGS
         .get(sig as usize)
-        .unwrap_or(&signal::_signal_strings[0]) // Unknown signal message
+        .unwrap_or(&signal::SIGNAL_STRINGS[0]) // Unknown signal message
         .as_ptr() as *mut c_char
 }
 

tests/Makefile

@@ -25,6 +25,7 @@ EXPECT_NAMES=\
 	locale \
 	math \
 	netdb/getaddrinfo \
+	psignal \
 	ptrace \
 	regex \
 	select \

tests/psignal.c

@@ -0,0 +1,22 @@
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include "test_helpers.h"
+
+int main(void) {
+    puts("------psignal------");
+    psignal(SIGUSR1, "a prefix");
+    puts("------  end  ------");
+    puts("------psiginfo-----");
+    siginfo_t info = { 0 };
+    info.si_code = SI_USER;
+    info.si_pid = 42;
+    info.si_uid = 1337;
+    info.si_addr = (void *)0xdeadbeef;
+    info.si_value.sival_ptr = (void *)0xfedface;
+    psiginfo(&info, "another prefix");
+    puts("------        -----");
+}