Auto merge of #2304 - mkroening:sigrt, r=JohnTitor

Add SIGRTMAX and SIGRTMIN on linux-like systems

Fixes #1883. This is based on #2195, which has not seen activity in a while.

The original issue was resolved by making `__libc_current_sigrtmax` and `__libc_current_sigrtmax` `pub`.

I also added a test similar to `errqueue`'s, where the actual value of the macro is compared to `libc`'s implementation.

Closes #2195

Author: bors

libc-test/Cargo.toml

@@ -71,6 +71,11 @@ name = "errqueue"
 path = "test/errqueue.rs"
 harness = true
 
+[[test]]
+name = "sigrt"
+path = "test/sigrt.rs"
+harness = true
+
 [[test]]
 name = "semver"
 path = "test/semver.rs"

libc-test/build.rs

@@ -26,6 +26,13 @@ fn do_cc() {
     if target.contains("android") || target.contains("linux") {
         cc::Build::new().file("src/errqueue.c").compile("errqueue");
     }
+    if target.contains("linux")
+        || target.contains("l4re")
+        || target.contains("android")
+        || target.contains("emscripten")
+    {
+        cc::Build::new().file("src/sigrt.c").compile("sigrt");
+    }
 }
 
 fn do_ctest() {

libc-test/semver/linux.txt

@@ -1972,6 +1972,8 @@ SIGEV_SIGNAL
 SIGEV_THREAD
 SIGPOLL
 SIGPWR
+SIGRTMAX
+SIGRTMIN
 SIGSTKSZ
 SIOCADDMULTI
 SIOCADDRT

libc-test/src/sigrt.c

@@ -0,0 +1,9 @@
+#include <signal.h>
+
+int sigrtmax() {
+  return SIGRTMAX;
+}
+
+int sigrtmin() {
+  return SIGRTMIN;
+}

libc-test/test/sigrt.rs

@@ -0,0 +1,32 @@
+//! Compare libc's SIGRTMAX and SIGRTMIN functions against the actual C macros
+
+extern crate libc;
+
+#[cfg(any(
+    target_os = "linux",
+    target_os = "l4re",
+    target_os = "android",
+    target_os = "emscripten"
+))]
+mod t {
+    use libc;
+
+    extern "C" {
+        pub fn sigrtmax() -> libc::c_int;
+        pub fn sigrtmin() -> libc::c_int;
+    }
+
+    #[test]
+    fn test_sigrtmax() {
+        unsafe {
+            assert_eq!(libc::SIGRTMAX(), sigrtmax());
+        }
+    }
+
+    #[test]
+    fn test_sigrtmin() {
+        unsafe {
+            assert_eq!(libc::SIGRTMIN(), sigrtmin());
+        }
+    }
+}

src/unix/linux_like/mod.rs

@@ -1418,6 +1418,14 @@ f! {
 }
 
 safe_f! {
+    pub fn SIGRTMAX() -> ::c_int {
+        unsafe { __libc_current_sigrtmax() }
+    }
+
+    pub fn SIGRTMIN() -> ::c_int {
+        unsafe { __libc_current_sigrtmin() }
+    }
+
     pub {const} fn WIFSTOPPED(status: ::c_int) -> bool {
         (status & 0xff) == 0x7f
     }
@@ -1480,6 +1488,11 @@ safe_f! {
 }
 
 extern "C" {
+    #[doc(hidden)]
+    pub fn __libc_current_sigrtmax() -> ::c_int;
+    #[doc(hidden)]
+    pub fn __libc_current_sigrtmin() -> ::c_int;
+
     pub fn sem_destroy(sem: *mut sem_t) -> ::c_int;
     pub fn sem_init(sem: *mut sem_t, pshared: ::c_int, value: ::c_uint) -> ::c_int;
     pub fn fdatasync(fd: ::c_int) -> ::c_int;