Move the libgccjit.so file in a target directory

Since GCC is not multi-target, we need multiple libgccjit.so.
Our solution to have a directory per target so that we can have multiple
libgccjit.so.

Author: antoyo

src/lib.rs

@@ -181,18 +181,18 @@ pub struct GccCodegenBackend {
 
 static LTO_SUPPORTED: AtomicBool = AtomicBool::new(false);
 
-fn libgccjit_path(sysroot_path: &Path) -> PathBuf {
+fn libgccjit_path(sysroot_path: &Path, target_triple: &str) -> PathBuf {
     let sysroot_lib_dir = sysroot_path.join("lib");
-    sysroot_lib_dir.join("libgccjit.so")
+    sysroot_lib_dir.join(target_triple).join("libgccjit.so")
 }
 
-fn load_libgccjit_if_needed(sysroot_path: &Path) {
+fn load_libgccjit_if_needed(sysroot_path: &Path, target_triple: &str) {
     if gccjit::is_loaded() {
         // Do not load a libgccjit second time.
         return;
     }
 
-    let libgccjit_target_lib_file = libgccjit_path(sysroot_path);
+    let libgccjit_target_lib_file = libgccjit_path(sysroot_path, target_triple);
     let path = libgccjit_target_lib_file.to_str().expect("libgccjit path");
 
     let string = CString::new(path).expect("string to libgccjit path");
@@ -216,9 +216,9 @@ impl CodegenBackend for GccCodegenBackend {
         // invalid.
         // This is the case for instance in Rust for Linux where they specify --sysroot=/dev/null.
         for path in sess.opts.sysroot.all_paths() {
-            let libgccjit_target_lib_file = libgccjit_path(path);
+            let libgccjit_target_lib_file = libgccjit_path(path, &sess.target.llvm_target);
             if let Ok(true) = fs::exists(libgccjit_target_lib_file) {
-                load_libgccjit_if_needed(path);
+                load_libgccjit_if_needed(path, &sess.target.llvm_target);
                 break;
             }
         }