[RFC] algol68: Use correct library file extension on macos and windows

[Jose E. Marchesi]

Hi Pietro.

> Sending as RFC because I haven't been able to test on a mac yet.
> --8<--
>
> Macos uses .dylib as extension for libraries. And Windows uses .dll.
> Use those extensions when opening library files to search for imports.
>
> Signed-off-by: Pietro Monteiro <pietro@sociotechnical.xyz>
> ---
>  gcc/algol68/a68-imports.cc | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
>
> diff --git a/gcc/algol68/a68-imports.cc b/gcc/algol68/a68-imports.cc
> index 8b77bbf0b76..7c5ef826274 100644
> --- a/gcc/algol68/a68-imports.cc
> +++ b/gcc/algol68/a68-imports.cc
> @@ -363,6 +363,30 @@ a68_try_suffixes (std::string *pfilename)
>        return fd;
>      }
>  
> +#if defined (__APPLE__)
> +  /* Macos uses .dylib as extension for libraries.  */
> +  const char* basename = lbasename (pfilename->c_str());
> +  size_t basename_pos = basename - pfilename->c_str ();
> +  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;
> +    }
> +#elsif defined (_WIN32)
> +  /* Windows uses .dll.  */
> +  const char* basename = lbasename (pfilename->c_str());
> +  size_t basename_pos = basename - pfilename->c_str ();
> +  filename = pfilename->substr (0, basename_pos) + "lib" + basename + ".dll";

I think in Windows DLLs are usually called FOO.dll, not libFOO.dll.
That said, mingw32 uses libFOO.dll.

We probably want to try for both, first libFOO.dll then FOO.dll?

> +  fd = open (filename.c_str (), O_RDONLY | O_BINARY);
> +  if (fd >= 0)
> +    {
> +      *pfilename = filename;
> +      return fd;
> +    }
> +#else
> +  /* Other supported systems use .so.  */
>    const char* basename = lbasename (pfilename->c_str());
>    size_t basename_pos = basename - pfilename->c_str ();
>    filename = pfilename->substr (0, basename_pos) + "lib" + basename + ".so";
> @@ -372,6 +396,7 @@ 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);
>
> base-commit: 5dc5dd6ed9b4759d278a07f95949c3f241626651