libabigail/doc/manuals/abidw.rst

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======
abidw
======
abidw reads a shared library in `ELF`_ format and emits an XML
representation of its ABI to standard output. The emitted
representation includes all the globally defined functions and
variables, along with a complete representation of their types. It
also includes a representation of the globally defined ELF symbols of
the file. The input shared library must contain associated debug
information in `DWARF`_ format.
Invocation
==========
::
abidw [options] [<path-to-elf-file>]
Options
=======
* ``--help | -h``
Display a short help about the command and exit.
* ``--debug-info-dir | -d`` <*dir-path*>
In cases where the debug info for *path-to-elf-file* is in a
separate file that is located in a non-standard place, this tells
``abidw`` where to look for that debug info file.
Note that *dir-path* must point to the root directory under which
the debug information is arranged in a tree-like manner. Under
Red Hat based systems, that directory is usually
``<root>/usr/lib/debug``.
Note that this option is not mandatory for split debug information
installed by your system's package manager because then
``abidw`` knows where to find it.
* ``--out-file`` <*file-path*>
This option instructs ``abidw`` to emit the XML representation of
*path-to-elf-file* into the file *file-path*, rather than emitting
it to its standard output.
* ``--noout``
This option instructs ``abidw`` to not emit the XML representation
of the ABI. So it only reads the ELF and debug information,
builds the internal representation of the ABI and exits. This
option is usually useful for debugging purposes.
* ``--check-alternate-debug-info`` <*elf-path*>
If the debug info for the file *elf-path* contains a reference to
an `alternate debug info <alt-di-label>`_ file, ``abidw`` checks
that it can find that alternate debug info file. In that case, it
emits a meaningful success message mentioning the full path to the
alternate debug info file found. Otherwise, it emits an error
code.
* ``--check-alternate-debug-info-base-name`` <*elf-path*>
Like ``--check-alternate-debug-info``, but in the success message,
only mention the base name of the debug info file; not its full path.
* ``--load-all-types``
Add support for abicompat weak mode This patch implements the weak mode of abicompat. In this mode, just the application and the new version of the library are provided. The types of functions and variables of the library that are consumed by the application are compared to the types of the functions and variables expected by the application. The goal is to check if the types of the declarations consumed by the application and provided by the library are compatible with what the application expects. The abicompat first gets the set of symbols undefined in the application and exported by the library. It then builds the set of declarations exported by the library that have those symbols. We call these the set of declarations of the library that are consumed by the application. Note that the debug information for the application does not contain the declarations of the functions/variables whose symbols are undefined. So we can not just read them to compare them to declarations exported by the library. But the *types* of the variables and the *sub-types* of the functions whose symbols are undefined in the application are present in the debug information of the application. So in the weak mode, abicompat compare the *types* of the declarations consumed by the application as expected by the application (described by the debug information of the application) with the types of the declarations exported by the library. To do this a number of changes were necessary. The patch builds a representation of all the types found in the application's debug info. Before that, only the types that are reachable from exported declarations were represented. The abidw tool got a new --load-all-types to test this new ability of loading all types. The patch also adds support for looking a type, not by name, but by its internal representation. In the comparison engine, function_type_diff is introduced to represent changes between two function types. For this, a new class type_or_decl_base has been introduced in the IR. It's now the base class for both decl_base and type_base. And abigail::comparison::diff now takes two pointers of type_or_decl, not decl_base anymore. So function_type_diff can take two function_type now; not that a function_type has no declaration so it doesn't inherit decl_base. A bunch of changes got made just to adjust to this modification. A number of fixes were made too, to make this work, like adding missing comparison operators, removing asserts that too strong, etc.. The patch also adjust the test suite as well as the documentation. * include/abg-fwd.h (class type_or_decl_base): Forward declare this. (is_decl, is_type, is_function_type, get_name, get_type_name) (get_function_type_name, get_pretty_representation) (lookup_function_type_in_corpus, lookup_type_in_translation_unit) (lookup_function_type_in_translation_unit) (synthesize_function_type_from_translation_unit) (hash_type_or_decl): New function declarations. * src/abg-corpus.cc (lookup_type_in_corpus) (lookup_function_type_in_corpus): Define new functions. * include/abg-ir.h (translation_unit::lookup_function_type_in_translation_unit): Declare new friend function. (class type_or_decl_base): Declare this. (operator==(const type_or_decl_base&, const type_or_decl_base&)): Declare new operator. (operator==(const type_or_decl_base_sptr&, const type_or_decl_base_sptr&)): Likewise. (class {decl_base, type_base}): Make these class inherit type_or_decl_base. (decl_base::get_member_scopes): New const overload. (bool operator==(const function_decl::parameter_sptr&, const function_decl::parameter_sptr&)): New operator. (function_type::get_parameters): Remove the non-const overload. (function_type::get_pretty_representation): Declare new member function. (method_type::get_pretty_representation): Likewise. * src/abg-ir.cc (bool operator==(const type_or_decl_base&, const type_or_decl_base&)): Define new equality operator. (bool operator==(const type_or_decl_base_sptr&, const type_or_decl_base_sptr&)): Likewise. (strip_typedef): Do not expect canonicalized types anymore. Now the system accepts (and expects) canonicalized types in certain cases. For instance, non-complete types and aggregated types that contain non-complete sub-types. (get_name, get_function_type_name, get_type_name) (get_pretty_representation, is_decl, is_type, is_function_type) (lookup_function_type_in_translation_unit) (synthesize_function_type_from_translation_unit) (lookup_type_in_scope, lookup_type_in_translation_unit): Define new functions or new overloads. (bool operator==(const function_decl::parameter_sptr&, const function_decl::parameter_sptr& r)): Define new operator. (function_type::get_parameters): Remove non-const overload. (function_type::get_pretty_representation): Define new function. (function_type::traverse): Adjust. (method_type::get_pretty_representation): Likewise. (function_decl::get_pretty_representation): Avoid emitting the type of cdtors. (hash_type_or_decl): Define new function. * include/abg-dwarf-reader.h (create_read_context) (read_corpus_from_elf): Take a new 'read_all_types' flag. * src/abg-dwarf-reader.cc (read_context::load_all_types_): New flag. (read_context::read_context): Initialize it. (read_context::canonical_types_scheduled): If some types still have non-canonicalized sub-types, then do not canonicalize them. (read_context::load_all_types): New member functions. (build_function_decl): Do not represent void return type like empty type anymore, rather, represent it like a void type node. (build_ir_node_from_die): When asked, load all types including those that are not reachable from an exported declaration. (create_read_context, read_corpus_from_elf): Take a new 'load_all_types' flag and honour it. * src/abg-reader.cc (read_context::type_is_from_translation_unit): Support looking up function types in the current translation unit, now that we now how to lookup function types. * include/abg-comparison.h (diff_context::{has_diff_for, add_diff, set_canonical_diff_for, set_or_get_canonical_diff_for, get_canonical_diff_for}): Make these take instances of type_or_decl_base_sptr, instead of decl_base_sptr. (diff::diff): Likewise. (diff::{first_subject, second_subject}): Make these return type_or_decl_base_sptr instead of decl_base_sptr. (type_diff_base::type_diff_base): Make these take instances of type_or_decl_base_sptr instead of decl_base_sptr. (distinct_diff::distinct_diff): Likewise. (distinct_diff::{first, second}): Make these return type_or_decl_base_sptr instead of decl_base_sptr. (distinct_diff::entities_are_of_distinct_kinds): Make these take instances of type_or_decl_base_sptr instead of decl_base_sptr. (class function_type_diff): Create this new type. It's a factorization of the function_decl_diff type. * src/abg-comparison.cc (): * src/abg-comp-filter.cc ({harmless, harmful}_filter::visit): Adjust as diff::{first,second}_subject() now returns a type_or_decl_base_sptr, no more a decl_base_sptr. (decls_type, decls_diff_map_type): Remove these typedefs and replace it with ... (types_or_decls_type, types_or_decls_diff_map_type): ... these. (struct {decls_hash, decls_equals): Remove these type sand replace them with ... (struct {types_or_decls_hash, types_or_decls_equals}): ... these. ({type_suppression, variable_suppression}::suppresses_diff): Adjust. (diff_context::priv::decls_diff_map): Replace this with ... (diff_context::priv::types_or_decls_diff_map): ... this. (diff_context::{has_diff_for, add_diff, get_canonical_diff_for, set_canonical_diff_for, set_or_get_canonical_diff_for}): Take type_or_decl_base_sptr instead of decl_base_sptr. (diff::priv::{first, second}_subject): Make the type of these be type_or_decl_base_sptr, no more decl_base_sptr. (diff::priv::priv): Adjust for the subjects of the diff being of type type_or_decl_sptr now, no more decl_base_sptr. (diff_less_than_functor::operator()(const diff_sptr, const diff_sptr) const): Adjust. (diff::diff): djust for the subjects of the diff being of type type_or_decl_sptr now, no more decl_base_sptr. (diff::{first,second}_subject): Make the type of these be type_or_decl_base_sptr, no more decl_base_sptr. (report_size_and_alignment_changes): Likewise. (type_diff_base::type_diff_base): Make the type of this be type_or_decl_base_sptr instead of type_base_sptr. (distinct_diff::distinct_diff): Make this take instances of type_or_decl_base_sptr instead of decl_base_sptr. (distinct_diff::{first, second, entities_are_of_distinct_kinds}): Likewise. (distinct_diff::has_changes): Simplify logic. (distinct_diff::report): Adjust. (compute_diff_for_types): Add an additional case to support the new function_type. (report_size_and_alignment_changes): Make this take instances of type_or_decl_base_sptr instead of decl_base_sptr. (class_diff::priv::member_type_has_changed): Return an instance of type_or_decl_base_sptr rather than a decl_base_sptr. (class_diff::report): Adjust. (diff_comp::operator()(const diff&, diff&) const): Adjust. (enum function_decl_diff::priv::Flags): Remove. (function_decl_diff::priv::{first_fn_flags_, second_fn_flags_, fn_flags_changes_}): Remove. (function_decl_diff::priv::{fn_is_declared_inline_to_flag, fn_binding_to_flag}): Remove. (function_decl_diff::{deleted_parameter_at, inserted_parameter_at}): Remove. (function_decl_diff::ensure_lookup_tables_populated): Empty this. (function_decl_diff::chain_into_hierarchy): Adjust. (function_decl_diff::function_decl_diff): This now only takes the subjects. It's body is now empty. (function_decl_diff::{return_type_diff, subtype_changed_parms, removed_parms, added_parms, type_diff}): Remove these member functions. (function_decl_diff::type_diff): Define new member function. (function_decl_diff::report): Simplify logic by using the reporting of the child type diff node. (compute_diff): Likewise, in the overload for function_decl_sptr simplify logic by using the child type diff object. (function_type_diff::priv): Define new type. (function_type_diff::{function_type_diff, ensure_lookup_tables_populated, deleted_parameter_at, inserted_parameter_at, finish_diff_type, first_function_type, second_function_type, return_type_diff, subtype_changed_parms, removed_parms, added_parms, get_pretty_representation, has_changes, has_local_changes, report, chain_into_hierarchy}): Define new functions. (compute_diff): Define new overload for function_type_sptr. * tools/abicompat.cc (options::weak_mode): New data member. (options::options): Initialize it. (enum abicompat_status): New enum (abicompat_status operator|(abicompat_status, abicompat_status)) (abicompat_status& operator|=(abicompat_status &, abicompat_status)) (abicompat_status operator&(abicompat_status, abicompat_status)): New operators to manipulate the abicompat_status enum. (display_usage): Add help string for the new --weak-mode option. (parse_command_line): Add the new --weak-mode command line argument. If the tool is called with just the application and one library then assume that we are in the weak mode. (perform_compat_check_in_normal_mode): Define new function, factorized from what was in the main function. (perform_compat_check_in_weak_mode): Define new function. (struct {fn,var}_change): Define new types. (main): Use perform_compat_check_in_weak_mode() and perform_compat_check_in_normal_mode(). * tools/abidiff.cc (main): Adjust. * tools/abidw.cc: (options::load_all_types): Add new data member. (options::options): Initialize it. (display_usage): New help string for --load-all-types. (parse_command_line): Support the new --load-all-types option. (main): Adjust and honour the --load-all-types option. * tools/abilint.cc (main): Adjust. * doc/manuals/abicompat.rst: Update documentation for the new weak mode. Also provide stuff that was missing from the examples provided. * doc/manuals/abidw.rst: Update documentation for the new --load-all-types option. * tests/print-diff-tree.cc (main): Adjust. * tests/test-diff-dwarf.cc (main): Likewise. * tests/test-read-dwarf.cc (main): Likewise. * tests/data/test-abicompat/test0-fn-changed-app: Recompile this. * tests/data/test-abicompat/libtest5-fn-changed-libapp-v{0,1}.so: New new test input binaries * tests/data/test-abicompat/test5-fn-changed-app: Likewise. * tests/data/test-abicompat/test6-var-changed-app: Likewise. * tests/data/test-abicompat/libtest6-var-changed-libapp-v{0,1}.so: Likewise. * tests/data/test-abicompat/test5-fn-changed-report-0.txt: Reference output for one test above. * tests/data/test-abicompat/test6-var-changed-report-0.txt: Likewise. * tests/data/test-abicompat/test5-fn-changed-app.cc: Source file for a binary above. * tests/data/test-abicompat/test5-fn-changed-libapp-v{0,1}.{h,cc}: Likewise. * tests/data/test-abicompat/test6-var-changed-libapp-v{0,1}.{cc,h}: Likewise. * tests/data/test-abicompat/test6-var-changed-app.cc: Likewise. * tests/data/Makefile.am: Add the test related files above to the source distribution. * tests/test-abicompat.cc (in_out_spec): Add the new test input above to the list of inputs to feed to this test harness. (main): Support taking just the app and one library. * tests/data/test-read-dwarf/test{0, 1, 2.so, 3.so, 5.o, 8-qualified-this-pointer.so,}.abi: Adjust for void type being really emitted now, as opposed to just being an empty type. Signed-off-by: Dodji Seketeli <dodji@redhat.com>
2015-04-01 10:13:38 +00:00
By default, ``libabigail`` (and thus ``abidw``) only loads types
that are reachable from functions and variables declarations that
are publicly defined and exported by the binary. So only those
types are present in the output of ``abidw``. This option however
makes ``abidw`` load *all* the types defined in the binaries, even
those that are not reachable from public declarations.
* ``--abidiff``
Load the ABI of the ELF binary given in argument, save it in
libabigail's XML format in a temporary file; read the ABI from the
temporary XML file and compare the ABI that has been read back
against the ABI of the ELF binary given in argument. The ABIs
should compare equal. If they don't, the program emits a
diagnostic and exits with a non-zero code.
This is a debugging and sanity check option.
Add a --stats to abidiff and abidw For now, this new --stats emits diagnostics about the number of types canonicalized at the very end of building the ABI corpus as well as the number of types that were scheduled for late canonicalizing and that couldn't be canonicalized. * include/abg-dwarf-reader.h (get_show_stats) (set_show_stats): New accessors for a new "show_stats" property of the dwarf reader context. * src/abg-dwarf-reader.cc: Include iostream to use std::cerr. (dwarf_reader::show_stats_): New data member. (dwarf_reader::dwarf_reader): Initialize it. (dwarf_reader::show_stats) (get_show_stats) (set_show_stats): Define new accessors. (dwarf_reader::die_type_map): Add const overload to this accessor. (dwarf_reader::lookup_type_from_die_offset): Make this accessor const. (dwarf_reader::add_late_canonicalized_types_stats): New member function. (dwarf_reader::perform_late_type_canonicalizing): Emit the statistics about late-canonicalized types if the user asked for it. * tools/abidiff.cc (options::show_stats): New data member. (options::options): Initialize it. (display_usage): Document it. (parse_command_line): Parse the new --stats option. (main): Create a dwarf reader context, set the show_stats to it and then use that context to read the corpora before diffing them. * tools/abidw.cc (options::show_stats): New data member. (options::options): Initialize it. (display_usage): Document it. (parse_command_line): Parse the new --stats option. (main): Set the show_stats to the dwarf reader context before using it. * doc/manuals/abidiff.rst: Update the manual. * doc/manuals/abidw.rst: Update the manual. Signed-off-by: Dodji Seketeli <dodji@redhat.com>
2015-08-20 10:28:38 +00:00
* ``--stats``
Emit statistics about various internal things.
Notes
=====
.. _alt-di-label:
Alternate debug info files
--------------------------
As of the version 4 of the DWARF specification, `Alternate debug
information <http://www.dwarfstd.org/ShowIssue.php?issue=120604.1>`_
is a `GNU`_ extension to the DWARF specification. It has however been
proposed for inclusion into the upcoming version 5 of the DWARF
standard. You can read more about the GNU extensions to the DWARF
standard `here
<https://fedorahosted.org/elfutils/wiki/DwarfExtensions>`_.
.. _ELF: http://en.wikipedia.org/wiki/Executable_and_Linkable_Format
.. _DWARF: http://www.dwarfstd.org
.. _GNU: http://www.gnu.org