Commit Graph

5 Commits

Author SHA1 Message Date
Dodji Seketeli
b2e5366d3f Introduce the concept of environment
There are resources needed by the type system and other artifacts of
libabigail.  Today, when the life time of those resources need to be
greater than all of artifacts of Abigail, then said resources are made
global.

But then global resources are not great, if anything because they
complicate the future use of the library in concurrent computing
setups.

As I was in the need to add one resource to be used by the type
system, I decided to sit down and first overhaul how these long lived
resources needed to be handled.

And here comes the concept of "environment".  An environment is a
place where one can put resources that need to live longer than all
the other artifacts of the Abigail system.  And so, the code that
creates Abigail artifacts needs and environment of for said artifacts
to use.  In other words, artifacts now use an environment.

This has interesting and strong implications.  We can only compare two
artifacts if they use the same environment.  This is quite a strong
requirement.

But then when this requirement is fulfilled, comparing two types
amounts to just comparing two pointer values; hash values for types
can also be cached.  Now *that* is great for speed of comparison, is
it not?

This patch introduce the concept environment (which is basically a new
abigail::ir::environment type), removes the global variables and uses
the environment instead.  Each ABI artifact (either type or decl) now
has a ::get_environment() member function to get its environment.

This patch also disables the caching of hash values because the
caching must happen only *after* all types have been canonicalized.
We were not respecting that requirement until now, and that introduces
wrong hash values.  A subsequent patch is going to re-introduce hash
value caching again, once the infrastructure is in place to set a flag
in the environment (hah!) once type canonicalization is done, and then
later read that flag when some client code requests a hash value, to
know if we should look in the hash value cache or not.

The patch obviously changes the output of numerous regression tests
(if anything b/c it disables hash value caching) so 'make check'
yields regressions.  But then, it's only the subsequent patch that
updates the tests.

	* include/abg-ir.h: Adjust note about memory management.
	(class environment): Declare new class.
	(translation_unit::translation_unit): Take an environment in
	parameter.
	(translation_unit::{g,s}et_environment): Declare new member
	functions.
	(type_or_decl_base::{g,s}et_environment): Likewise.
	(type_or_decl_base::{get_cached_hash_value,
	set_cached_hash_value}): Change the name of
	decl_base::peek_hash_value() and decl_base::set_hash() here into
	these and move them here.
	(type_or_decl_base::hashing_started): Move
	decl_base::hashing_started() here.
	({g,s}et_environment_for_artifact): Declare new functions.
	(class decl_base): Move member functions hashing_started(),
	peek_hash_value() and set_hash() on to the type_or_decl_base base
	class.
	(scope_decl::scope_decl): Initialize the virtual member
	type_or_decl_base().
	(type_decl::{get_void_type_decl,
	get_variadic_parameter_type_decl}): Remove these static member
	functions.  They are now non-static member functions of the new
	environment type.
	* src/abg-ir.cc (class environment_setter): New internal class.
	(get_canonical_types_map): Remove.  This now becomes a member
	function of the environment type.
	(class usage_watchdog): Remove.
	(usage_watchdog_{s,w}ptr): Remove these typedefs.
	(get_usage_watchdog_wptr, ref_usage_watchdog)
	(maybe_cleanup_type_system_data): Remove these functions.
	(translation_unit::priv::usage_watchdog_): Remove data member.
	(translation_unit::priv::env_): New data member.
	(translation_unit::priv::priv): Take an environment and initialize
	the new env_ data member.  Do not initialize the removed
	usage_watchdog_.
	(translation_unit::translation_unit): Take an environment
	parameter.
	(translation_unit::get_global_scope): Set the environment of a new
	global scope.
	(translation_unit::{g,s}et_environment): New accessors.
	(translation_unit::bind_function_type_life_time): Set the
	environment of the function type.
	(struct environment::priv): New class.
	(environment::{environment, ~environment, get_canonical_types_map,
	get_variadic_parameter_type_decl, canonicalization_is_done}): New
	member functions.
	(struct type_or_decl_base::priv): New class.
	(type_or_decl_base::{type_or_decl_base, hashing_started,
	get_cached_hash_value, set_cached_hash_value, set_environment,
	get_environment, traverse}): New member functions.
	({s,g}get_environment_for_artifact): New functions.
	(decl_base::priv::{hash_, hashing_started}): Remove.
	(decl_base::priv::priv): Adjust.
	(decl_base::decl_base): In the copy constructor, initialize the
	virtual base type_or_decl_base.  Do not initialize hash_ and
	hashing_started data member that got removed.
	(decl_base::{hashing_started, peek_hash_value, set_hash}): Remove
	member functions.
	(strip_typedef): Set the environment of the new type which has its
	typedefs stripped off.  Adjust the call to type_or_void().
	(scope_decl::{add, insert}_member_decl): Set the environment of
	the new member decl to the environment of its scope.
	(synthesize_type_from_translation_unit)
	(synthesize_function_type_from_translation_unit): Set the
	environment for the newly synthesized type. Adjust calls to
	type_or_void().
	(type_or_void): Take an environment in parameter.  Get the void
	type from the environment.
	(get_canonical_types_map): Remove.
	(type_base::get_canonical_type_for): Get the canonical types map
	from the environment, not from a global variable.
	(type_decl::{get_void_type_decl,
	get_variadic_parameter_type_decl}): Remove.
	(pointer_type_def::pointer_type_def): Adjust call to type_or_void.
	(reference_type_def::reference_type_def): Likewise.
	(function_decl::parameter::get_pretty_representation): Get the
	variadic parameter type decl from the environment.
	(class_decl::priv::classes_being_compared_): Remove static data
	member.
	(class_decl::priv::{mark_as_being_compared,
	unmark_as_being_compared, comparison_started): Use the "classes
	being compared" map from the environment.
	(class_decl::base_spec::get_hash): Adjust.
	(keep_type_alive): Get the alive types array from the environment)
	not from a global variable anymore.
	(get_next_string): Put the counter in thread-local storage.
	* src/abg-hash.cc (scope_decl:#️⃣:operator())
	(function_decl:#️⃣:operator()): Do not handle caching (here).
	* include/abg-corpus.h (corpus::{g,s}et_environment): Declare new
	accessors.
	* src/abg-corpus.cc (corpus::priv::env): New data member.
	(corpus::priv::priv): Initialize it.
	(corpus::corpus):  Take an environment in parameter.
	(corpus::{g,s}et_environment): Define new member functions
	(corpus::add): Set the environment of the newly added translation
	unit, if it's not set already set.  In any case, assert that the
	translation unit must use the same environment as the corpus.
	* include/abg-dwarf-reader.h (create_read_context)
	(read_corpus_from_elf): Take an environment parameter.
	({s,g}et_debug_info_root_path, {s,g}et_environment): Declare new
	functions.
	* src/abg-dwarf-reader.cc (read_context::{env_,
	offline_callbacks_}): New data members.
	(read_context::read_context): Initialize them.
	(read_context::clear_per_translation_unit_data): Do not touch the
	void type declaration, it doesn't belong to the translation unit.
	(read_context::{env, offline_callbacks}): New accessors.
	(read_context::{create_default_dwfl}): New member function.
	(read_context::dwfl_handle): Add a setter overload.
	({s,g}et_debug_info_root_path): Define new accessors.
	(create_default_dwfl, create_dwfl_sptr, create_default_dwfl_sptr):
	Remove these.
	(build_translation_unit_and_add_to_ir): Adjust to pass the
	environment to the newly created translation unit.
	(build_function_decl): Adjust to pass the environment to the
	created function and parameter types.  Get variadic parameter type
	node from the current environment, not from a global variable.
	And do not try to canonicalize function types here.
	(read_debug_info_into_corpus): Set the environment of the newly
	created corpus.
	(build_ir_node_for_void_type): Get the void type node from the
	current environment, rather than from a global variable.
	(create_read_context): Take the environment in parameter.
	Create the default dwarf front end library handle using the new
	member function of the read context.  Set the current environment
	used by the reader.
	(read_corpus_from_elf): Take an environment in
	parameter. Overhaul.  This is now simpler.
	(has_alt_debug_info): Adjust the call to create_read_context() to
	make it pass an empty environment.
	* include/abg-fwd.h (class environment): Forward declare.
	* include/abg-reader.h (read_translation_unit_from_file)
	(read_translation_unit_from_buffer)
	(read_translation_unit_from_istream)
	(read_corpus_from_native_xml): Take an environment in parameter.
	* src/abg-reader.cc (read_context::m_env): New data member.
	(read_context::read_context): Initialize it.
	(read_context::{get_environment, set_environment}): New data
	member.
	(read_translation_unit): Set environment of the new translation
	unit.
	(read_corpus_from_input): Set the environment of the new corpus.
	(read_translation_unit_from_file)
	(read_translation_unit_from_buffer)
	(read_translation_unit_from_istream, read_corpus_from_native_xml):
	Take an environment in parameter.
	(build_function_parameter): Get variadic parameter type from the environment.
	* src/abg-comparison.cc (compute_diff): Add asserts in all the
	overloads to ensure that the artifact being compared come from the
	same environment.
	* tests/print-diff-tree.cc (main): Create an env for the ABI
	artifacts to use.
	* tests/test-abidiff.cc (main): Likewise.
	* tests/test-diff-dwarf.cc (main): Likewise.
	* tests/test-ir-walker.cc (main): Likewise.
	* tests/test-read-dwarf.cc (main): Likewise.
	* tests/test-read-write.cc (main): Likewise.
	* tools/abicompat.cc (main): Likewise.
	* tools/abidiff.cc (main): Likewise.
	* tools/abidw.cc (main): Likewise.
	* tools/abilint.cc (main): Likewise.
	* tools/abipkgdiff.cc (main): Likewise.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>
2015-09-07 23:35:29 +02:00
Dodji Seketeli
5b09ea77e2 Handle the life time of the map of canonical types
While working on something else, it turned out that we need to cleanup
(de-allocate) the map of canonical types when all the translation
units that own types are de-allocated.  Otherwise, when new
translation units are created later, the types in the canonical types
map become unrelated to the types in these new translation units,
leading to memory management issues.

This patch introduces a "usage watchdog" which detects when no
translation unit uses the type system anymore.  That usage watchdog is
then used in the destructor of the translation_unit type to
de-allocate the global data that is logically owned by by the type
system.

The patch also changes the API to read translation units and corpora
in a way that forces users to get a handle on the resulting shared
pointer.

	* include/abg-ir.h (type_base::canonical_types_map_type): Move
	this typedef into abg-ir.cc and out of the type_base namespace.
	(type_base::get_canonical_types_map): Likewise.
	* src/abg-ir.cc (canonical_types_map_type): New typedef that got
	moved here from type_base::canonical_types_map_type.
	(get_canonical_types_map): Likewise got moved here from
	type_base::get_canonical_types_map.  Made static in the process.
	(class usage_watchdog): New type.
	(usage_watchdog_sptr, usage_watchdog_wptr): New typedefs.
	(get_usage_watchdog, get_usage_watchdog_wptr, ref_usage_watchdog)
	(maybe_cleanup_type_system_data): New static functions.
	(translation_unit::priv::usage_watchdog_): Add new data member.
	(translation_unit::priv::priv): Get a reference on the usage
	watchdog.
	(translation_unit::priv::~priv): If the usage watchdog says that
	the type system is not used, then cleanup the global data
	logically owned by the type system.

	* include/abg-dwarf-reader.h (read_corpus_from_elf): Make this
	return a corpus and set the status by reference using a parameter.
	* src/abg-dwarf-reader.cc (read_corpus_from_elf): Implement the
	above.
	* include/abg-reader.h (read_translation_unit_from_file)
	(read_translation_unit_from_buffer)
	(read_translation_unit_from_istream): Remove the overloads that do
	not return a translation_unit_sptr and that pass it as a
	parameter.  Only keep the overloads that return a
	translation_unit_sptr, forcing users of the API to own a proper
	reference on the resulting translation_unit pointer.  That is
	important to handle the life time of the global data of the type
	system that need to be cleared when the last translation unit is
	de-allocated.
	* src/abg-reader.cc (read_translation_unit_from_input): Make this
	return a translation_unit_sptr.
	(read_translation_unit_from_file)
	(read_translation_unit_from_buffer)
	(read_translation_unit_from_istream): Remove the overloads that do
	not return a translation_unit_sptr and that pass it as a
	parameter.  Only keep the overloads that return a
	translation_unit_sptr.
	(read_to_translation_unit): Make this return a
	translation_unit_sptr.
	* tests/print-diff-tree.cc (main): Adjust.
	* tests/test-diff-dwarf.cc (main): Likewise.
	* tests/test-ir-walker.cc (main): Likewise.
	* tests/test-read-dwarf.cc (main): Likewise.
	* tests/test-read-write.cc (main): Likewise.
	* tools/abicompat.cc (main): Likewise.
	* tools/abidiff.cc (main): Likewise.
	* tools/abidw.cc (main): Likewise.
	* tools/abilint.cc (main): Likewise.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>
2015-07-09 11:12:40 +02:00
Dodji Seketeli
8b28d171c3 Canonicalize types either early or late after TU reading
While trying to diff two identical files (abidiff foo.so foo.so) it
appeared that canonicalizing types during e.g, the DWARF reading
process was leading to subtle errors because it's extremely hard to
know when a type is complete.  That is, during the building of a class
type C, a pointer to C can be built before C is complete.  Worse, even
after reading the DIE (from DWARF) of class C, there can be DIE seen
later in the translation unit that modifies type C.  In these late
cases, one needs to wait -- not only until C is fully built, but also
sometimes, after the translation unit is fully built -- to
canonicalize C and then the pointer to C.  This kind of things.

So now there are two possible points in time when canonicalization of
a type can happen.  It can happen early, when the type is built.  This
is the case for basic types and composite types for which all
sub-types are canonicalized already.  It can happen late, right after
we've finished reading the debug info for the current translation
unit.

So this patch fixes the IR traversal and uses that to walk the
translation unit (or even types) after it's built.  It does away with
the first attempt to perform early canonicalizing only.

The patch also handles type canonicalizing while reading xml-abi
format.

	* include/abg-fwd.h (is_class_type)
	(type_has_non_canonicalized_subtype): Declare new functions.
	(is_member_type): Remove the overload that takes a decl_base_sptr.
	It's superfluous.  We just need the one that takes a
	type_base_sptr.
	* include/abg-ir.h (translation_unit::{is_constructed,
	set_is_constructed}): Add new methods.
	(class_decl::has_virtual_member_functions): Likewise.
	(class decl_base): Makes it virtually inherit ir_traversable_base.
	(class type_base): Make this virtually inherit traversable_base
	too.
	(type_base::canonicalize): Renamed enable_canonical_equality
	into this.
	(type_base::traverse): Declare new virtual method.
	(canonicalize): Renamed enable_canonical_equality into this.
	(scope_type_decl::traverse): Declare new virtual method.
	(namespace_decl::get_pretty_representation): Declare new virtual
	method.
	(function_type::traverse): Likewise.
	(class_decl::base_spec::traverse): Likewise.
	(ir_node_visitor::visit): Remove the overloads and replace each of
	them with a pair of ...
	(ir_node_visitor::{visit_begin, visit_end}): ... of these.
	* include/abg-traverse.h (traversable_base::visiting): New
	method.
	(traversable_base::visiting_): New data member.
	(traversable_base::traversable_base): New constructor.
	* src/abg-ir.cc ({scope_decl, type_decl, namespace_decl,
	qualified_type_def, pointer_type_def, reference_type_def,
	array_type_def, enum_type_decl, typedef_decl, var_decl,
	function_decl, function_decl::parameter, class_decl,
	class_decl::member_function_template,
	class_decl::member_class_template, function_tdecl,
	class_tdecl}::traverse): Fix this to properly set the
	traversable_base::visiting_ flag and to reflect the new signatures
	of the ir_node_visitor methods.
	({type_base, scope_type_decl, function_type,
	class_decl::base_spec}::traverse): New method.
	(type_base::get_canonical_type_for): Handle the case of the type
	already having a canonical type.  Properly hash the type using the
	dynamic type hasher.  Look through declaration-only classes to
	consider the definition of the class instead.  Fix logic to have a
	single pointer of return, to ease debugging.
	(canonicalize): Renamed enable_canonical_equality into this.
	(namespace_decl::get_pretty_representation): Define new method.
	(ir_node_visitor::visit): Replace each of these overloads with a
	pair of visit_begin/visit_end ones.
	(translation_unit::priv::is_constructed_): New data member.
	(translation_unit::priv::priv): Initialize it.
	(translation_unit::{is_constructed, set_is_constructed}): Define
	new methods.
	(is_member_type(const decl_base_sptr)): Remove.
	(is_class_type(decl_base *d)): Define new function.
	(class_decl::has_virtual_member_functions): Define new method.
	(equals(const class_decl&, const class_decl&, change_kind*)): If
	the containing translation unit is not constructed yet, do not
	take virtual member functions in account when comparing the
	classes.  This is because when reading from DWARF, there can be
	DIEs that change the number of virtual member functions after the
	DIE of the class.  So one needs to start taking virtual members
	into account only after the translation unit has been constructed.
	(class non_canonicalized_subtype_detector): Define new type.
	(type_has_non_canonicalized_subtype): Define new function.
	* src/abg-corpus.cc (symtab_build_visitor_type::visit): Renamed
	this into symtab_build_visitor_type::visit_end.
	* src/abg-dwarf-reader.cc (die_type_map_type): New typedef.
	(die_class_map_type): This is now a typedef on a map of
	Dwarf_Off/class_decl_sptr.
	(read_context::{die_type_map_, alternate_die_type_map_,
	types_to_canonicalize_, alt_types_to_canonicalize_}): New data
	members.
	(read_context::{associate_die_to_decl,
	associate_die_to_decl_primary}): Make these methods public.
	(read_context::{associate_die_to_type,
	lookup_type_from_die_offset, is_wip_class_die_offset,
	types_to_canonicalize, schedule_type_for_canonicalization}):
	Define new methods.
	(build_type_decl, build_enum_type)
	(build_class_type_and_add_to_ir, build_qualified_type)
	(build_pointer_type_def, build_reference_type, build_array_type)
	(build_typedef_type, build_function_decl): Do not canonicalize
	types here.
	(maybe_canonicalize_type): Define new function.
	(build_ir_node_from_die): Take a new flag that says if the ir node
	is a member type/function or not. Early-canonicalize base types.
	Canonicalize composite types that have only canonicalized
	sub-types.  Schedule the other types for late canonicalizing.  For
	class types, early canonicalize those that are non-member types,
	that are fully constructed and that have only canonicalized
	sub-types.  Adjust to the new signature of build_ir_node_from_die.
	(get_scope_for_die, build_namespace_decl_and_add_to_ir)
	(build_qualified_type, build_pointer_type_def)
	(build_reference_type, build_array_type, build_typedef_type)
	(build_var_decl, build_function_decl): Adjust for the new
	signature of build_ir_node_from_die.
	(build_translation_unit_and_add_to_ir): Likewise.  Perform the
	late canonicalizing of the types that have been scheduled for
	that.
	(build_class_type_and_add_to_ir): Return a class_decl_sptr, not a
	decl_base_sptr.  Adjust for the new signature of
	build_ir_node_from_die.  Early canonicalize member types that are
	created and added to a given class, or schedule them for late
	canonicalizing.
	* src/abg-reader.cc (class read_context::{m_wip_classes_map,
	m_types_to_canonicalize}): New data members.
	(read_context::{clear_types_to_canonicalize,
	clear_wip_classes_map, mark_class_as_wip, unmark_class_as_wip,
	is_wip_class, maybe_canonicalize_type,
	schedule_type_for_late_canonicalizing,
	perform_late_type_canonicalizing}): Add new method definitions.
	(read_context::clear_per_translation_unit_data): Call
	read_context::clear_types_to_canonicalize().
	(read_translation_unit_from_input): Call
	read_context::perform_late_type_canonicalizing() at the end of the
	function.
	(build_function_decl): Fix the function type canonicalizing (per
	translation) that was already in place.  Do the canonicalizing of
	these only when the type is fully built.  Oops.  This was really
	brokend.  Also, when the function type is constructed, consider it
	for type canonicalizing.
	(build_type_decl): Early canonicalize basic types.
	(build_qualified_type_decl, build_pointer_type_def)
	(build_pointer_type_def, build_reference_type_def)
	(build_array_type_def, build_enum_type_decl, build_typedef_decl):
	Handle the canonicalizing for these composite types: either early
	or late.
	(build_class_decl): Likewise.  Also, mark this class a 'being
	built' until it's fully built.  This helps the canonicalizing code
	to know that it should leave a class alone until it's fully built.
	* tests/test-ir-walker.cc (struct name_printing_visitor): Adjust
	to the visitor methods naming change.
	* configure.ac: Generate the tests/runtestcanonicalizetypes.sh
	testing script from tests/runtestcanonicalizetypes.sh.in.
	* tests/runtestcanonicalizetypes.sh.in: Add the template for the
	new runtestcanonicalizetypes.sh script that test for type
	canonicalizing.
	* tests/Makefile.am: Add the new runtestcanonicalizetypes.sh
	regression testing script to the build system.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>
2015-02-18 21:32:37 +01:00
Dodji Seketeli
76837d1cbf Update copyright years
* include/abg-comp-filter.h: Update copyright years.
	* include/abg-comparison.h: Likewise.
	* include/abg-config.h: Likewise.
	* include/abg-corpus.h: Likewise.
	* include/abg-diff-utils.h: Likewise.
	* include/abg-dwarf-reader.h: Likewise.
	* include/abg-fwd.h: Likewise.
	* include/abg-hash.h: Likewise.
	* include/abg-ini.h: Likewise.
	* include/abg-ir.h: Likewise.
	* include/abg-libxml-utils.h: Likewise.
	* include/abg-libzip-utils.h: Likewise.
	* include/abg-reader.h: Likewise.
	* include/abg-sptr-utils.h: Likewise.
	* include/abg-traverse.h: Likewise.
	* include/abg-viz-common.h: Likewise.
	* include/abg-viz-dot.h: Likewise.
	* include/abg-viz-svg.h: Likewise.
	* include/abg-writer.h: Likewise.
	* src/abg-comp-filter.cc: Likewise.
	* src/abg-comparison.cc: Likewise.
	* src/abg-config.cc: Likewise.
	* src/abg-corpus.cc: Likewise.
	* src/abg-diff-utils.cc: Likewise.
	* src/abg-dwarf-reader.cc: Likewise.
	* src/abg-hash.cc: Likewise.
	* src/abg-ini.cc: Likewise.
	* src/abg-ir.cc: Likewise.
	* src/abg-libxml-utils.cc: Likewise.
	* src/abg-libzip-utils.cc: Likewise.
	* src/abg-reader.cc: Likewise.
	* src/abg-traverse.cc: Likewise.
	* src/abg-viz-common.cc: Likewise.
	* src/abg-viz-dot.cc: Likewise.
	* src/abg-viz-svg.cc: Likewise.
	* src/abg-writer.cc: Likewise.
	* tests/print-diff-tree.cc: Likewise.
	* tests/test-abidiff.cc: Likewise.
	* tests/test-alt-dwarf-file.cc: Likewise.
	* tests/test-core-diff.cc: Likewise.
	* tests/test-diff-dwarf.cc: Likewise.
	* tests/test-diff-filter.cc: Likewise.
	* tests/test-diff-suppr.cc: Likewise.
	* tests/test-diff2.cc: Likewise.
	* tests/test-ir-walker.cc: Likewise.
	* tests/test-lookup-syms.cc: Likewise.
	* tests/test-read-dwarf.cc: Likewise.
	* tests/test-read-write.cc: Likewise.
	* tests/test-utils.cc: Likewise.
	* tests/test-utils.h: Likewise.
	* tests/test-write-read-archive.cc: Likewise.
	* tools/abg-tools-utils.cc: Likewise.
	* tools/abg-tools-utils.h: Likewise.
	* tools/abiar.cc: Likewise.
	* tools/abidiff.cc: Likewise.
	* tools/abidw.cc: Likewise.
	* tools/abilint.cc: Likewise.
	* tools/abisym.cc: Likewise.
	* tools/binilint.cc: Likewise.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>
2015-01-07 17:52:10 +01:00
Dodji Seketeli
29036c19ce Rename test-walker.cc into test-ir-walker.cc
* tests/test-ir-walker.cc: Renamed test-walker.cc into this.
	* tests/Makefile.am: Adjust.  The generated binary is now testirwalker.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>
2014-03-27 13:01:17 +01:00