The adainclude subdirectory containing the sources of the GNAT
run-time library, and the adalib subdirectory containing the
ALI files and the static and/or shared GNAT library, are located
in the gcc target-dependent area:
target=$prefix/lib/gcc/gcc-*dumpmachine*/gcc-*dumpversion*/
As indicated above, on some platforms several run-time libraries are supplied. These libraries are installed in the target dependent area and contain a complete source and binary subdirectory. The detailed description below explains the differences between the different libraries in terms of their thread support.
The default run-time library (when GNAT is installed) is `rts-native'. This default run time is selected by the means of soft links. For example on x86-linux:
    --
    --  $(target-dir)
    --      |
    --      +--- adainclude----------+
    --      |                        |
    --      +--- adalib-----------+  |
    --      |                     |  |
    --      +--- rts-native       |  |
    --      |    |                |  |
    --      |    +--- adainclude <---+
    --      |    |                |
    --      |    +--- adalib <----+
    --      |
    --      +--- rts-sjlj
    --           |
    --           +--- adainclude
    --           |
    --           +--- adalib
If the `rts-sjlj' library is to be selected on a permanent basis, these soft links can be modified with the following commands:
    $ cd $target
    $ rm -f adainclude adalib
    $ ln -s rts-sjlj/adainclude adainclude
    $ ln -s rts-sjlj/adalib adalib
Alternatively, you can specify rts-sjlj/adainclude in the file
$target/ada_source_path and rts-sjlj/adalib in
$target/ada_object_path.
Selecting another run-time library temporarily can be achieved by using the `–RTS' switch, e.g., `–RTS=sjlj'