$NetBSD: normalise.txt,v 1.2 2017/06/11 19:34:44 joerg Exp $

The first phase of wrapper processing for cc-ish wrappers is argument
normalisation.  This simplifies processing in latter steps.

Transformations done in this phase:

1. Empty arguments are suppressed.

2. Arguments of the form "-Xlinker -Wl,foo" are converted to "-Wl,foo".
All other arguments of the form "-Xlinker foo" are converted to "-Wl,foo".

3. Arguments of the form "-Wl,*,*" are split into separate -Wl options.

4. Arguments of the form "-I foo", "-D foo", "-L foo" or
"-Wl,-L -Wl,foo" are converted to the single argument form "-Ifoo",
"-Dfoo", "-Lfoo" and "-Wl,-Lfoo" respectively.

5. Arguments of the form "-Wl,-L,foo" are converted to "-Lfoo".

6. Arguments of the form "-Wl,-rpath-link -Wl,foo" are converted to
the single argument form "-Wl,-rpath-link,foo".

7. Arguments of the form "-Rfoo", "-R foo", "-Wl,-Rfoo", "-Wl,-R -Wl,foo",
"-Wl,-rpath -Wl,foo" or "--Wl,-rpath -Wl,foo" are converted to the single
canonical argument form "-Wl,-rpath,foo".  All -Wl,-rpath options with relative
path (e.g. not starting with /) are dropped.

8. Full path names that end up in
"/lib([a-zA-Z0-9_-])*\.s[ol](\.[0-9][^/]*)$ are replaced by "-Ldir -l\1"
with "dir" being the base name of the argument.  This is not done for
arguments to -o, --dynamic-linker or -Wl,--dynamic-linker.

The last option in the following set is used to set the operation mode:
- "-E" -> preprocess
- "-S" -> assemble
- "-c" -> compile
- "-shared" -> link-shared
and the default operation mode is link-executable. Note that the operation mode
is not necessarily determined correctly for the libtool wrapper.