1 files changed, 22 insertions, 0 deletions
diff --git a/m4/ghc_select_file_extensions.m4 b/m4/ghc_select_file_extensions.m4
new file mode 100644
index 0000000000..751298a7f3
--- /dev/null
+++ b/m4/ghc_select_file_extensions.m4
@@ -0,0 +1,22 @@
+AC_DEFUN([GHC_SELECT_FILE_EXTENSIONS],
+[
+    $2=''
+    $3='.so'
+    case $1 in
+    *-unknown-cygwin32)
+        AC_MSG_WARN([GHC does not support the Cygwin target at the moment])
+        AC_MSG_WARN([I'm assuming you wanted to build for i386-unknown-mingw32])
+        exit 1
+        ;;
+    # examples: i386-unknown-mingw32, i686-w64-mingw32, x86_64-w64-mingw32
+    *-mingw32)
+        windows=YES
+        $2='.exe'
+        $3='.dll'
+        ;;
+    # apple platform uses .dylib (macOS, iOS, ...)
+    *-apple-*)
+        $3='.dylib'
+        ;;
+    esac
+])