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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
doc Add a new --noout option to abidw 2015-08-29 16:23:15 +02:00
include Introduce the concept of environment 2015-09-07 23:35:29 +02:00
m4 Delete ltsugar.m4 and pkg.m4 files from m4/ 2015-01-06 09:54:45 +01:00
scripts Initial DOT work. 2013-07-23 23:13:55 +02:00
src Introduce the concept of environment 2015-09-07 23:35:29 +02:00
tests Introduce the concept of environment 2015-09-07 23:35:29 +02:00
tools Introduce the concept of environment 2015-09-07 23:35:29 +02:00
.gitignore Update .gitignore 2014-11-01 12:10:06 +01:00
abigail.m4 For usage from within GCC set header path to $includedir/libabigail 2013-08-14 16:10:15 +02:00
AUTHORS Initial AUTHORS and README 2013-02-28 13:25:20 +01:00
ChangeLog Update ChangeLog file 2015-06-25 08:13:21 +02:00
COMMIT-LOG-GUIDELINES Allow introductory text in commit log and ignore it when generating ChangeLog 2014-11-18 23:18:06 +01:00
COMPILING White space fix in COMPILING 2013-08-22 17:40:50 +02:00
config.h.in Make abipkgdiff compare tar archives containing binaries 2015-08-22 14:32:20 +02:00
configure.ac Misc style cleanups 2015-08-22 14:32:20 +02:00
CONTRIBUTING Update the CONTRIBUTING file 2015-03-19 12:47:59 +01:00
COPYING Use a better wording for the COPYING file 2015-04-22 09:53:18 +02:00
COPYING-GPLV3 Update licence texts 2015-04-20 13:51:21 +02:00
COPYING-LGPLV2 Initial import of gen-changelog.py 2014-11-18 23:18:06 +01:00
COPYING-LGPLV3 LGPLv3 License the library 2013-07-23 23:13:55 +02:00
gen-changelog.py [gen-changelog] Make subject line always come first 2014-11-18 23:18:06 +01:00
install-sh Add missing autoconfiscation files into version control 2013-03-01 00:47:49 +01:00
libabigail.pc.in Make libxml2 a private dependency wrt pkconfig 2013-08-22 17:41:29 +02:00
ltmain.sh Add missing autoconfiscation files into version control 2013-03-01 00:47:49 +01:00
Makefile.am Update licence texts 2015-04-20 13:51:21 +02:00
README Fix wording in README 2015-09-05 10:30:00 +02:00
test21-type-suppr-0.suppr Pimplify abigail::comparison::diff type 2014-09-19 12:28:18 +02:00
test21-type-suppr-report-0.txt Pimplify abigail::comparison::diff type 2014-09-19 12:28:18 +02:00

This is the Application Binary Interface Generic Analysis and
Instrumentation Library.

It aims at constructing, manipulating, serializing and de-serializing
ABI-relevant artifacts.

The set of artifacts that we are intersted is made of quantities like
types, variable, fonctions and declarations of a given library or
program.  For a given library or program this set of quantities is
called an ABI corpus.

This library aims at (among other things) providing a way to compare
two ABI Corpora (apparently the plural of corpus is copora, heh,
that's cool), provide detailed information about their differences,
and help build tools to infer interesting conclusions about these
differences.

You are welcome to contribute to this project after reading the files
CONTRIBUTING and COMMIT-LOG-GUIDELINES files in the source tree.

Communicating with the maintainers of this project -- including
sending patches to be include to the source code -- happens via email
at libabigail@sourceware.org.