1 files changed, 10 insertions, 4 deletions
diff --git a/compiler/rustc_session/src/filesearch.rs b/compiler/rustc_session/src/filesearch.rs
index bdeca91eb64..207ba5157bd 100644
--- a/compiler/rustc_session/src/filesearch.rs
+++ b/compiler/rustc_session/src/filesearch.rs
@@ -78,10 +78,16 @@ fn current_dll_path() -> Result<PathBuf, String> {
                 if libc::dladdr(addr, &mut info) == 0 {
                     return Err("dladdr failed".into());
                 }
-                if info.dli_fname.is_null() {
-                    return Err("dladdr returned null pointer".into());
-                }
-                let bytes = CStr::from_ptr(info.dli_fname).to_bytes();
+                #[cfg(target_os = "cygwin")]
+                let fname_ptr = info.dli_fname.as_ptr();
+                #[cfg(not(target_os = "cygwin"))]
+                let fname_ptr = {
+                    if info.dli_fname.is_null() {
+                        return Err("dladdr returned null pointer".into());
+                    }
+                    info.dli_fname
+                };
+                let bytes = CStr::from_ptr(fname_ptr).to_bytes();
                 let os = OsStr::from_bytes(bytes);
                 Ok(PathBuf::from(os))
             }