Enable ZMQ_HAVE_STRLCPY for GLIBC >= 2.38

src/lib.rs

@@ -1,6 +1,6 @@
 use std::{
-    env, fs,
-    fs::File,
+    env,
+    fs::{self, File},
     io::Write,
     path::{Path, PathBuf},
 };
@@ -56,6 +56,24 @@ where
     Err(())
 }
 
+#[cfg(target_env = "gnu")]
+mod glibc {
+    use std::path::Path;
+
+    // Attempt to compile a c program that links to strlcpy from the std
+    // library to determine whether glibc packages it.
+    pub(crate) fn has_strlcpy() -> bool {
+        let path = Path::new(env!("CARGO_MANIFEST_DIR")).join("src/strlcpy.c");
+
+        cc::Build::new()
+            .cargo_metadata(false)
+            .warnings_into_errors(true)
+            .file(path)
+            .try_compile("has_strlcpy")
+            .is_ok()
+    }
+}
+
 /// The location of a library.
 #[derive(Debug, Clone)]
 pub struct LibLocation {
@@ -338,6 +356,7 @@ impl Build {
             build.include(out_includes);
         };
 
+        let mut has_strlcpy = false;
         if target.contains("windows") {
             // on windows vista and up we can use `epoll` through the `wepoll` lib
             add_c_sources(
@@ -379,22 +398,31 @@ impl Build {
             build.define("ZMQ_HAVE_UIO", "1");
 
             if target.contains("android") {
-                build.define("ZMQ_HAVE_STRLCPY", "1");
+                has_strlcpy = true;
             }
 
             if target.contains("musl") {
-                build.define("ZMQ_HAVE_STRLCPY", "1");
+                has_strlcpy = true;
             }
         } else if target.contains("apple") {
             create_platform_hpp_shim(&mut build);
             build.define("ZMQ_IOTHREAD_POLLER_USE_KQUEUE", "1");
             build.define("ZMQ_POLL_BASED_ON_POLL", "1");
             build.define("HAVE_STRNLEN", "1");
-            build.define("ZMQ_HAVE_STRLCPY", "1");
             build.define("ZMQ_HAVE_UIO", "1");
             build.define("ZMQ_HAVE_IPC", "1");
+            has_strlcpy = true;
         }
 
+        // https://github.com/jean-airoldie/zeromq-src-rs/issues/28
+        #[cfg(target_env = "gnu")]
+        if !has_strlcpy && glibc::has_strlcpy() {
+            has_strlcpy = true;
+        }
+
+        if has_strlcpy {
+            build.define("ZMQ_HAVE_STRLCPY", "1");
+        }
         let out_dir = PathBuf::from(env::var("OUT_DIR").unwrap());
         let lib_dir = out_dir.join("lib");
 

src/strlcpy.c

@@ -0,0 +1,7 @@
+#include <string.h>
+
+int main() {
+    char buf[1];
+    (void)strlcpy(buf, "a", 1);
+    return 0;
+}