[PATCH] algol68: Use correct library file extension on darwin and windows

[Pietro Monteiro]

Darwin uses .dylib as extension for libraries.  Windows uses .dll, and
sometimes doesn't prefix the library filename with "lib".

Use those extensions when opening library files to search for imports
on thoses OSes.  Search for file with both the lib prefix and withouti
on Windows.

gcc/algol68/ChangeLog:

        * a68-imports.cc (a68_try_suffixes): Use .dylib suffix on Darwin.
        Use .ddl suffix and optional lib prefix on Windows.

Signed-off-by: Pietro Monteiro <pie...@sociotechnical.xyz>
---
 gcc/algol68/a68-imports.cc | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/gcc/algol68/a68-imports.cc b/gcc/algol68/a68-imports.cc
index 8b77bbf0b76..e0fe87368e5 100644
--- a/gcc/algol68/a68-imports.cc
+++ b/gcc/algol68/a68-imports.cc
@@ -365,6 +365,35 @@ a68_try_suffixes (std::string *pfilename)
 
   const char* basename = lbasename (pfilename->c_str());
   size_t basename_pos = basename - pfilename->c_str ();
+
+#if defined (__APPLE__)
+  /* Macos uses .dylib as extension for libraries.  */
+  filename = pfilename->substr (0, basename_pos) + "lib" + basename + ".dylib";
+  fd = open (filename.c_str (), O_RDONLY | O_BINARY);
+  if (fd >= 0)
+    {
+      *pfilename = filename;
+      return fd;
+    }
+#elif defined (_WIN32)
+  /* Windows uses .dll.  Maybe prefixed with lib.  */
+  filename = pfilename->substr (0, basename_pos) + "lib" + basename + ".dll";
+  fd = open (filename.c_str (), O_RDONLY | O_BINARY);
+  if (fd >= 0)
+    {
+      *pfilename = filename;
+      return fd;
+    }
+  /* Maybe not prefixed with lib.  */
+  filename = pfilename->substr (0, basename_pos) + basename + ".dll";
+  fd = open (filename.c_str (), O_RDONLY | O_BINARY);
+  if (fd >= 0)
+    {
+      *pfilename = filename;
+      return fd;
+    }
+#else
+  /* Other supported systems use .so.  */
   filename = pfilename->substr (0, basename_pos) + "lib" + basename + ".so";
   fd = open (filename.c_str (), O_RDONLY | O_BINARY);
   if (fd >= 0)
@@ -372,6 +401,7 @@ a68_try_suffixes (std::string *pfilename)
       *pfilename = filename;
       return fd;
     }
+#endif
 
   filename = pfilename->substr (0, basename_pos) + "lib" + basename + ".a";
   fd = open (filename.c_str (), O_RDONLY | O_BINARY);
-- 
2.43.0