Add --enable-debug-type-canonicalization to configure
This configure option adds the possibility to debug the type
canonicalization process specifically.
When this new configure option is turned on, in
ir::get_canonical_type_for, when the type T, candidate for
canonicalization is compared to a given canonical type C, the
comparison is done twice; once using structural equality and once
using canonical equality whenever it's possible. For all the
sub-types of T and C, structural equality and canonical equality must
yield the same result. Otherwise, an error message is emitted and the
process aborts.
This all happens when using the abidw program with the --enable-tc or
--enable-type-canonicalization option.
This has proven to be very helpful to detect type canonicalization issues.
For instance, here is a trace of canonicalization issue that was
detected thanks to this patch:
$ build/tools/abidw --debug-tc /usr/lib64/libwiretap.so.11.0.8
structural & canonical equality different for type: function type void (wtap*)
in compare_types_during_canonicalization at: /home/dodji/git/libabigail/PR28364/src/abg-ir.cc:13575: execution should not have reached this point!
Abandon (core dumped)
This means that right after canonicalizing the type "void (wtap*)",
structural and canonical equality yield different results. So it
means there is a problem with that type specifically that makes its
canonicalization "go wrong". This requires further debugging to
understand, but at least, we are super close to the root cause of the
canonicalization problem.
* configure.ac: Support the new
--enable-debug-type-canonicalization option. Define macro
WITH_DEBUG_TYPE_CANONICALIZATION accordingly.
* doc/manuals/abidw.rst: Update documentation.
* include/abg-ir.h
(environment::debug_type_canonicalization_is_on): Declare new
member function if WITH_DEBUG_TYPE_CANONICALIZATION is defined.
* src/abg-ir-priv.h
(environment::priv::{use_canonical_type_comparison_,
debug_type_canonicalization_}): Define new data members if
WITH_DEBUG_TYPE_CANONICALIZATION is defined.
(environment::priv::priv): Initialize them.
* src/abg-ir.cc (try_canonical_compare): When
WITH_DEBUG_TYPE_CANONICALIZATION is defined, perform comparison
using either structural or canonical equality depending on the
environment::priv::use_canonical_type_comparison_ flag.
(environment::debug_type_canonicalization_is_on): Define member
function when WITH_DEBUG_TYPE_CANONICALIZATION is defined.
(compare_types_during_canonicalization): Define new function.
(type_base::get_canonical_type_for): Use the new function
compare_types_during_canonicalization.
* tools/abidw.cc (options::debug_type_canonicalization): Define
new data member.
(option::option): Initialize it.
(display_usage): Add help string for --debug-tc.
(parse_command_line): Support new option --debug-tc or
--debug-type-canonicalization.
(load_corpus_and_write_abixml): Turn type canonicalization
debugging on if --enable-tc is provided.
Signed-off-by: Dodji Seketeli <dodji@redhat.com>
6 files changed
