Bug 21058 - abipkgdiff wrongly drops non-public types

Bug 21058 - abipkgdiff wrongly drops non-public types

When using abipkgdiff types that are defined in files not present in
the devel packages provided by the --devel1 and --devel2 option are
dropped from the internal representation by default.

This has been designed as such, not only to avoid showing changes on
types that are not part of the public headers of a shared library, but
also to help lower the memory consumption of libabigail.

In this particular bug report, we see a library that uses types (in
its public interface) that are defined in headers of a *different*
package.  For instance, suppose a particular package foo that uses
types defined in headers of the glib package.  And some of those Glib
types can be present in its public interface.

So in this case, libabigail is dropping a type that is actually part
of the public interface of the library that is being analyzed, even if
the type was not defined in the devel package of the current package.

This patch addresses the issue by doing a number of things:

    1/ If a type is defined in a file which path starts with
    "/usr/include/", then consider it as a public type.  This is so
    that type coming from the public interface of other packages, and
    that are defined in system headers are considered as part of the
    public types of the package being analyzed.

    2/ by default, don't drop types not defined in the associated
    devel package.  This will hinder our ability to decrease the
    memory usage, but there have been a number of recent optimization
    that help in that regard independently.  So I am hoping this
    shouldn't have a big impact now.

    Incidentally, the option --dont-drop-private-types (from abidiff)
    is changed into --drop-private-types, so that interested users can
    still drop non-private types from the model, if they wish.  That
    --drop-private-types option is added to abipkgdiff too.

As the offended types are not dropped from the model anymore, the
usual filtering mechanisms of libabigail can take place.

	* doc/manuals/abidiff.rst (--dont-drop-private-types): Remove documentation.
	(--drop-private-types): Document this new option.
	* src/abg-tools-utils.cc: Update copyright notice
	(handle_fts_entry): On the generated suppression specification, do
	not set the flag to drop matched types.  Also, don't match types
	defined in files which patch start with "/usr/include/".
	* tools/abidiff.cc (options::options): Initialize the
	drop_private_types data member to false.
	(display_usage): Remove usage string for
	--dont-drop-private-types.  Add a new one for
	--drop-private-types.
	(parse_command_line): Don't part --dont-drop-private-types,
	rather, parse --drop-private-types.
	(set_suppressions): When the suppression for private types is
	generated, if --drop-private-types was provided, then instruct the
	suppression to drop matched types.
	* tools/abipkgdiff.cc (options::drop_private_types): New option.
	(options::options): Initialize the new drop_private_types data
	member to false.
	(display_usage): Add a usage string for --drop-private-types.
	(parse_command_line): Parse the new --drop-private-types option.
	(maybe_create_private_types_suppressions): Don't take just a
	package, but a package_descriptor because the latter carries the
	options.  So when the user used the --drop-private-types option,
	make the generated private types suppression to drop matched
	types.
	* tests/data/test-diff-pkg/tbb-4.1-9.20130314.fc22.x86_64--tbb-4.3-3.20141204.fc23.x86_64-report-1.txt:
	Adjust.
	* tests/test-diff-suppr.cc (in_out_specs): Likewise.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>