Print error on dlopen error

Author: antoyo

gccjit_sys/src/dynload.rs

@@ -4,13 +4,14 @@ pub use self::platform::Library;
 
 #[cfg(unix)]
 mod platform {
-    use std::ffi::{CStr, c_int, c_void};
+    use std::ffi::{CStr, c_char, c_int, c_void};
 
     #[link(name="dl")]
     extern "C" {
         fn dlopen(filename: *const i8, flag: c_int) -> *mut c_void;
         fn dlsym(handle: *mut c_void, symbol: *const i8) -> *mut c_void;
         fn dlclose(handle: *mut c_void) -> c_int;
+        fn dlerror() -> *const c_char;
     }
 
     pub struct Library(*mut c_void);
@@ -23,9 +24,13 @@ mod platform {
             const RTLD_NOW: c_int = 2;
             let handle = dlopen(path.as_ptr(), RTLD_NOW);
             if handle.is_null() {
+                let cstr = dlerror();
+                let cstr = CStr::from_ptr(cstr);
+                eprintln!("Dlerror: {:?}", cstr);
                 None
             }
             else {
+                eprintln!("Loading worked HERE");
                 Some(Self(handle))
             }
         }

gccjit_sys/src/lib.rs

@@ -339,14 +339,19 @@ macro_rules! extern_maybe_dlopen {
 
             #[cfg(feature="dlopen")]
             pub unsafe fn open(path: &CStr) -> Option<Self> {
-                let lib = unsafe { dynload::Library::open(path)? };
+                let lib = unsafe { dynload::Library::open(path) };
+                eprintln!("Opening lib: {}", lib.is_some());
+                let lib = lib?;
 
                 Some(Self {
                     $(
                     $(#[cfg($attr_name=$attr_value)])?
                     $func_name: unsafe { std::mem::transmute::<*mut (), unsafe extern "C" fn($($arg_type),*) $(-> $return_type)?>(
-                        lib.get(CStr::from_bytes_with_nul_unchecked(concat!(stringify!($func_name), "\0").as_bytes())
-                    )?) },
+                        {
+                            eprintln!("Attempting to load symbol: {}", stringify!($func_name));
+                            lib.get(CStr::from_bytes_with_nul_unchecked(concat!(stringify!($func_name), "\0").as_bytes()))?
+                        }
+                    ) },
                     )*
                     _lib: lib,
                 })

src/lib.rs

@@ -125,7 +125,9 @@ fn with_lib<T, F: Fn(&Libgccjit) -> T>(callback: F) -> T {
 pub fn load(path: &CStr) -> bool {
     let lib =
         LIB.get_or_init(|| {
-            unsafe { Libgccjit::open(path) }
+            let lib = unsafe { Libgccjit::open(path) };
+            eprintln!("Is some: {}", lib.is_some());
+            lib
         });
     lib.is_some()
 }