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8 Commits

Author SHA1 Message Date
Dodji Seketeli
74bd98766a test-alt-dwarf: Add missing dwz alt-debug file
It seems I forgot to add a dwz alt-debug file to the test material
included in the previous commit.

Fixed thus.

	* tests/data/test-alt-dwarf-file/libstdc++/libstdc++-report-1.txt:
	New reference test output.
	* tests/data/test-alt-dwarf-file/libstdc++/usr/lib/debug/.dwz/gcc-12.1.1-1.fc37.x86_64:
	New dwz alt-debug info file.
	* tests/data/Makefile.am: Add the test material above to source
	distribution.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>
2022-06-23 15:57:23 +02:00
Dodji Seketeli
72b46b2600 ir: Make canonicalization stable wrt typedefs in fn return types
In the grand scheme of things, two function return types can be equal
modulo typedefs.  Because those two function textual representations
are different, the two overall function types would end up having
different canonical types and thus, the two functions would be
considered as having different sub-types.  The harmless change pass
would then kick in and flag that change as harmless.  But then, "abidw
--abidiff" that is used for testing purposes would still be not happy.

This patch strips typedefs off of return types of function types when
the string representation is to be used for internal (e.g, type
canonicalization) purposes.

The fix for this change uncovered another issue:

When setting the naming typedefs for an (anonymous) C++ class, the
qualified name of the class was wrongly being set to the qualified
name of the typedef.  Only the name of the class should be affected,
in essence.  The qualified name would, ONLY as a result of the name
change, be adjusted.

This patch fixes those issues and adjusts the test suite accordingly.

	* src/abg-ir.cc (get_function_type_name, get_method_type_name):
	When the function type name is for internal purposes, strip
	potential typedefs off.
	(equal): In the overload for function_type, strip potential
	typedefs off of return types before comparing them.
	(decl_base::set_naming_typedef): Properly adjust the qualified
	name of the type to which a naming typedef is being set.
	* tests/data/test-alt-dwarf-file/libstdc++/libstdc++-report.txt:
	New reference test output.
	* tests/data/test-alt-dwarf-file/libstdc++/usr/lib/debug/usr/lib64/libstdc++.so.6.0.30-12.1.1-1.fc37.x86_64.debug:
	New binary test input.
	* tests/data/test-alt-dwarf-file/libstdc++/usr/lib64/libstdc++.so.6.0.30:
	New binary test input.
	* tests/data/Makefile.am: Add the new test material to source
	distribution.
	* tests/data/test-annotate/test15-pr18892.so.abi: Adjust.
	* tests/data/test-annotate/test17-pr19027.so.abi: Likewise.
	* tests/data/test-annotate/test21-pr19092.so.abi: Likewise.
	* tests/data/test-read-dwarf/PR25007-sdhci.ko.abi: Likewise.
	* tests/data/test-read-dwarf/test-libaaudio.so.abi: Likewise.
	* tests/data/test-read-dwarf/test-libandroid.so.abi: Likewise.
	* tests/data/test-read-dwarf/test15-pr18892.so.abi: Likewise.
	* tests/data/test-read-dwarf/test16-pr18904.so.abi: Likewise.
	* tests/data/test-read-dwarf/test17-pr19027.so.abi: Likewise.
	* tests/data/test-read-dwarf/test21-pr19092.so.abi: Likewise.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>
2022-06-23 13:29:53 +02:00
Dodji Seketeli
1cfbff1b30 rhbz1951526 - SELF CHECK FAILED for 'gimp-2.10'
This is a fix for bug https://bugzilla.redhat.com/show_bug.cgi?id=1951526.

Although it's a patch for one bug, it addresses several different
issues that cause the observed self comparison failure.  As is often
the case on this kind of problems, the failure is difficult to
reproduce on a synthetic test case so I'll explain the root causes in
this commit log.

There are 4 different root causes to this problem.  As I couldn't come
up with a reduced test case for each one of them I am adding the fixes
for those 4 issues in this commit, along with a new regression test
extracted from the initial bugzilla problem report.

So, overall, the symptom we are seeing here is that when we build an
IR for the input binary gimp-2.0, save that IR into abixml, and read
back that abixml into another IR, comparing the two IR shows changes;
it should show no change whatsoever.  This is what we call in
libabigail jargon a self comparison (or self check) failure.

As alluded to in my introduction above, there appear to be 4 different
root causes for that self comparison failure.

1/ The first cause has to do with a situation about two anymous enums
that are (wrongly) considered different from an ABI point of view.
Using the debugging capabilities recently gained by libabigail, I
could notice that the two enums are:

    (gdb) p debug(&l)
    enum __anonymous_enum__ : unnamed-enum-underlying-type-32
    {
      // size in bits: 32
      // translation unit: /usr/src/debug/gimp-2.10.22-2.el9.1.aarch64/app/<artificial>-757de
      // @: 0x698fb68, @canonical: 0

      GIMP_INTERPOLATION_NONE = 0,
      GIMP_INTERPOLATION_LINEAR = 1,
      GIMP_INTERPOLATION_CUBIC = 2,
      GIMP_INTERPOLATION_NOHALO = 3,
      GIMP_INTERPOLATION_LOHALO = 4,
    };

    $1 = (abigail::ir::decl_base *) 0x698fba0
    (gdb) p debug(&r)
    enum __anonymous_enum__ : unnamed-enum-underlying-type-32
    {
      // size in bits: 32
      // translation unit: /usr/src/debug/gimp-2.10.22-2.el9.1.aarch64/app/app.c
      // @: 0xa6d83e8, @canonical: 0

      GIMP_INTERPOLATION_NONE = 0,
      GIMP_INTERPOLATION_LINEAR = 1,
      GIMP_INTERPOLATION_CUBIC = 2,
      GIMP_INTERPOLATION_NOHALO = 3,
      GIMP_INTERPOLATION_LOHALO = 4,
      GIMP_INTERPOLATION_LANCZOS = 3,
    };

    $2 = (abigail::ir::decl_base *) 0xa6d8420
    (gdb)

Note how the second enum has a new enumerator named
'GIMP_INTERPOLATION_LANCZOS', but its value is '3', which is the exact
same value of as the one of the existing enumerator
GIMP_INTERPOLATION_NOHALO.

During type canonicalization of the IR from the input binary,
libabigail (wrongly) considers these two enums as being different.
This leads to the type 'Gimp*' (or anything type indirectly using any
one of the anonymous enums above) coming from one translation unit
being considered different from a type 'Gimp*' coming from another
translation unit, just because their are not using either one version
of the anonymous enum above or the other.

This leads to a *LOT* of spurious type changes from the first IR, that
are saved into abixml.

To fix this first problem, this patch introduces "two modes" of
comparing enums. There is a binary-only mode which only looks
enumerator values, not enumerator names.  And then there is the
source-level mode which looks at both enumerator names and values when
comparing enums.  The former mode is used during type
canonicalization.  However, when a change is detected between two
enums, then the diff-IR built to describe the change is constructed
using the later mode.  Using the later mode allows to describe
precisely things like enumerator insertion/removal by referring to the
names of the added/removed enumerators.

2/ The second root cause is that a struct, say, 'struct _GimpImage'
from a translation unit is considered different from a 'struct
_GimpImage' because the DWARF reader wrongly assign them different sizes.

Here is what it looks like in the debugger:

    (gdb) p debug(&l)
    struct _GimpImage
    {  // size in bits: 384
       // definition point: ../../app/core/gimpimage.h:39:1
       // translation unit: /usr/src/debug/gimp-2.10.22-2.el9.1.aarch64/app/<artificial>-757de
       // @: 0x69b9d10, @canonical: 0

      GimpViewable parent_instance;'
      Gimp* gimp;'
      GimpImagePrivate* priv;'
    };

    $8 = (abigail::ir::type_base *) 0x69b9d10
    (gdb) p debug(&r)
    struct _GimpImage
    {  // size in bits: 0
       // definition point: :0:0
       // translation unit: /usr/src/debug/gimp-2.10.22-2.el9.1.aarch64/app/<artificial>-8813f
       // @: 0x6ac7a50, @canonical: 0

    };

Notice how the second 'struct _GimpImage' has a size of zero.

This is because when reading the DWARF, we first encounter the DIE for
the first' struct _GimpImage' and we properly build a type for it,
along with its declaration.  Then when we encounter another DIE
defining 'struct _GimpImage' again, from a different translation unit,
the DWARF reader recognizes that it's a DIE for a declaration of
'struct _GimpImage' and fails to re-use the previous definition for
'struct _GimpImage'.  So it wrongly builds declaration-only 'struct
_GimpImage' for it, hence the second struct _GimpImage with a zero
size.

Here again that creates spurious changes (after type canonicalization)
in types using struct _GimpImage.  And that is a lot of types,
including things like 'Gimp*' and the like.

The fix for this root cause issue is to change
add_or_update_class_type in the DWARF reader to recognize that we are
seeing a type declaration for which there was already a definition and
return that definition instead of creating a new declaration.

3/ The third root cause is better explained with a "screen shot".
Consider these two 'versions' of the same struct _GdkDevice from two
different translation units:

    struct _GdkDevice
    {  // size in bits: 576
       // definition point: /usr/include/gtk-2.0/gdk/gdkinput.h:98:1
       // translation unit: /usr/src/debug/gimp-2.10.22-2.el9.1.aarch64/app/<artificial>-2d0352
       // @: 0x8820530, @canonical: 0

      GObject parent_instance;'
      gchar* name; // uses canonical type '@0x6892980'
      GdkInputSource source;'
      GdkInputMode mode;'
      gboolean has_cursor; // uses canonical type '@0x688dd00'
      gint num_axes; // uses canonical type '@0x688dd00'
      GdkDeviceAxis* axes;'
      gint num_keys; // uses canonical type '@0x688dd00'
      GdkDeviceKey* keys;'
    };

    $9 = (abigail::ir::type_base *) 0x8820530
    (gdb) p debug(&r)
    struct _GdkDevice
    {  // size in bits: 576
       // definition point: /usr/include/gtk-2.0/gdk/gdkinput.h:98:1
       // translation unit: /usr/src/debug/gimp-2.10.22-2.el9.1.aarch64/app/<artificial>-1fdb18
       // @: 0x7cd71e0, @canonical: 0

      GObject parent_instance;'
      gchar* _g_sealed__name; // uses canonical type '@0x6892980'
      GdkInputSource _g_sealed__source;'
      GdkInputMode _g_sealed__mode;'
      gboolean _g_sealed__has_cursor; // uses canonical type '@0x688dd00'
      gint _g_sealed__num_axes; // uses canonical type '@0x688dd00'
      GdkDeviceAxis* _g_sealed__axes;'
      gint _g_sealed__num_keys; // uses canonical type '@0x688dd00'
      GdkDeviceKey* _g_sealed__keys;'
    };

    $10 = (abigail::ir::type_base *) 0x7cd71e0
    (gdb)

Notice how the name of the second data member 'name' was changed to
'_g_sealed_name'.  A similar scheme happens to several other data
member names.  The offsets and types of the struct _GdkDevice haven't
changed however.  So from an ABI standpoint, the two versions of that
struct are equal.  Libabigail consider them different however.
Because that type is used by tons of other types of the binary being
analyzed, this leads to lots of spurious canonical type difference
that shouldn't be there.

These three issues are magnified by the fact that the gimp binary is
compiled using "link time optimization".  That brings in a lot more
opportunities to see these underlying issues that have been there for
a long time.

4/ The fourth and last root cause issue.  When the abixml writer emits
a translation unit (TU), it keeps track of the 'non-emitted referred
to type' of the currently emitted translation unit and emits them at
the end of each TU.  For instance, if the type 'Gimp*' (pointer to
Gimp) was emitted, and yet the referred-to type 'Gimp' wasn't emitted,
the TU writer makes sure to emit the referred-to 'Gimp' type at the
end of the TU.  This has been going on for quite some time now.

The problem however is that although the non-emitted referred-to type
was referred to in this current TU, it might no have been *DEFINED* in
this TU.  In that case, it should not be emitted in this TU.

Otherwise, the TU where that type is defined in the abixml might
appear different from where it is defined in the initial binary,
leading to self comparison failures down the road.

This patch ensures that a non-emitted referred-to type is always
emitted in the TU it belongs to.

5/ After doing all this, it appears that we were forgetting to emit
some function types that were defined in TUs emitted earlier and yet
were being referred-to later.  Looking closer, I realized that we
should just emit function types seen in a given TU, regardless of the
referred-to relation.

The problem with that is that function types are special in libabigail
because there are two situation in which they are created.

Basically, a function type is created by the DWARF DIE
DW_TAG_subroutine_type.  This is for instance how pointer to functions
are represented in DWARF, namely, by a DW_TAG_pointer_type that points
to a DW_TAG_subroutine_type.  That is represented in the libabigail ir
by an instance of the abigail::ir::function_type type.  This is
represented in abixml as a 'function-type' XML element.

But then, libabigail considers that all decls have a type.  This
applies obviously for variables or data member.  Right.  But then,
libabigail considers that a function is also a decl, which has a type.
And the type of a function is a function type, represented by the same
abigail::ir::function_type.  A practical difference with the former
situation is that function decls are *NOT* represented in abixml using
a 'function-type' element.  Instead a 'function-decl' XML element uses
return type and parameter elements to represent the types involved
with a function decl.

Said otherwise, the former 'function type' concept used to represent
the type of functions in the libabigail IR is artificial.  This
artificial-ness was not explicitly expressed in libabigail.  This
patch now expresses that artificial-ness for function types.  So the
abixml writer now just decide to not emit artificial function types,
and instead, emit all the non-artificial function types instead.

This addresses this last issues by being able to emit all
non-artificial function types defined in a given TU, without having to
bother with the fact that they are referred-to or not.

Together, fixing these 5 problems fixes this reported problem.

The changes to the reference test outputs are adjustments needed
because of the abixml output indeed changes.

	* include/abg-ir.h
	(environment::use_enum_binary_only_equality): Declare
	accessors.  (type_or_decl_base::{s,g}et_is_artificial):
	Likewise.  (decl_base::{s,g}et_is_artificial): Remove
	accessors.  * src/abg-ir.cc
	(environment::priv::use_enum_binary_only_equality): Define new
	data member.
	(environment::priv::use_enum_binary_only_equality): Define
	accessors.  (type_or_decl_base::priv::is_artificial_): Define
	new data member.  It has actually moved here from
	decl_base::priv::is_artificial_.
	(type_or_decl_base::priv::priv): Initialize it.
	(type_or_decl_base::{g,s}et_is_artificial): Define accessors.
	(decl_base::is_artificial_): Move this to
	type_or_decl_base::is_artificial_.
	(maybe_adjust_canonical_type): In a given class of equivalence
	of function types, if there is one non-artificial function
	type, then the entire class of equivalence is considered
	non-artificial; so flag the canonical function type as being
	non-artificial.  (is_enumerator_present_in_enum): Define new
	static function.  (equals): Re-arrange the overload for enums
	so the order of the enumerators doesn't count in the
	comparison.  Also, two enums with different numbers of
	enumerators can still be equal, with the right redundancy.  In
	the overload for var_decl, avoid taking into account the names
	of data members in the comparison.
	(enum_type_decl::enumerator::operator==): In the binary-level
	comparison mode, only compare the value of enumerators, not
	their name.  * src/abg-comparison.cc (compute_diff): In the
	overload for enum_type_decl, if the enums compare different
	using binary-level comparison, then use source-level
	comparison to build the diff-IR.  * src/abg-dwarf-reader.cc
	(read_context::compare_before_canonicalisation): Compare enums
	using binary-level comparison.  (add_or_update_class_type): If
	we are looking at the definition of an existing declaration
	that has been already defined then use the previous
	definition, in case we are going to need to update the
	definition.  Also, update the size only if it's needed.
	(build_function_type): By default, consider the newly built
	function type as artificial.  (build_ir_node_from_die): When
	looking at a DW_TAG_subroutine_type DIE, consider the built
	function type as non-artificial.  * src/abg-reader.cc
	(read_context::maybe_check_abixml_canonical_type_stability):
	Don't consider declaration-only classes in an ODR context
	because they don't have canonical types.
	(build_function_decl): Flag the function type of the function
	as artificial.  (build_class_decl): Make sure to reuse class
	types that were already created.  * src/abg-writer.cc
	(write_translation_unit): Allow emitting empty classes.  Make
	sure referenced types are emitting in the translation unit
	where they belong.  Avoid emitting artificial function types.
	*
	tests/data/test-alt-dwarf-file/rhbz1951526/rhbz1951526-report-0.txt:
	New test reference output.  *
	tests/data/test-alt-dwarf-file/rhbz1951526/usr/bin/gimp-2.10:
	New reference test binary input.  *
	tests/data/test-alt-dwarf-file/rhbz1951526/usr/lib/debug/.dwz/gimp-2.10.22-2.el9.1.aarch64:
	Likewise.  *
	tests/data/test-alt-dwarf-file/rhbz1951526/usr/lib/debug/usr/bin/gimp-2.10-2.10.22-2.el9.1.aarch64.debug:
	Likewise.  * tests/data/Makefile.am: Add the new test files to
	source directory.  * tests/test-alt-dwarf-file.cc: Add the new
	test inputs to this test harness.  *
	tests/data/test-abidiff/test-PR18791-report0.txt: Adjust.  *
	tests/data/test-abidiff/test-enum0-report.txt: Likewise.  *
	tests/data/test-annotate/libtest23.so.abi: Likewise.  *
	tests/data/test-annotate/libtest24-drop-fns-2.so.abi:
	Likewise.  *
	tests/data/test-annotate/libtest24-drop-fns.so.abi: Likewise.
	* tests/data/test-annotate/test-anonymous-members-0.o.abi:
	Likewise.  * tests/data/test-annotate/test13-pr18894.so.abi:
	Likewise.  * tests/data/test-annotate/test14-pr18893.so.abi:
	Likewise.  * tests/data/test-annotate/test15-pr18892.so.abi:
	Likewise.  * tests/data/test-annotate/test17-pr19027.so.abi:
	Likewise.  *
	tests/data/test-annotate/test18-pr19037-libvtkRenderingLIC-6.1.so.abi:
	Likewise.  *
	tests/data/test-annotate/test19-pr19023-libtcmalloc_and_profiler.so.abi:
	Likewise.  *
	tests/data/test-annotate/test20-pr19025-libvtkParallelCore-6.1.so.abi:
	Likewise.  * tests/data/test-annotate/test21-pr19092.so.abi:
	Likewise.  *
	tests/data/test-diff-dwarf-abixml/test0-pr19026-libvtkIOSQL-6.1.so.1.abi:
	Likewise.  *
	tests/data/test-diff-dwarf/PR25058-liblttng-ctl-report-1.txt:
	Likewise.  * tests/data/test-diff-dwarf/test6-report.txt:
	Likewise.  *
	tests/data/test-diff-filter/test31-pr18535-libstdc++-report-0.txt:
	Likewise.  *
	tests/data/test-diff-filter/test31-pr18535-libstdc++-report-1.txt:
	Likewise.  * tests/data/test-diff-filter/test8-report.txt:
	Likewise.  *
	tests/data/test-diff-pkg/spice-server-0.12.4-19.el7.x86_64-0.12.8-1.el7.x86_64-report-2.txt:
	Likewise.  *
	tests/data/test-diff-pkg/spice-server-0.12.4-19.el7.x86_64-0.12.8-1.el7.x86_64-report-3.txt:
	Likewise.  *
	tests/data/test-diff-pkg/tbb-4.1-9.20130314.fc22.x86_64--tbb-4.3-3.20141204.fc23.x86_64-report-0.txt:
	Likewise.  *
	tests/data/test-diff-pkg/tbb-4.1-9.20130314.fc22.x86_64--tbb-4.3-3.20141204.fc23.x86_64-report-1.txt:
	Likewise.  *
	tests/data/test-read-dwarf/PR22015-libboost_iostreams.so.abi:
	Likewise.  *
	tests/data/test-read-dwarf/PR22122-libftdc.so.abi: Likewise.
	* tests/data/test-read-dwarf/PR25007-sdhci.ko.abi: Likewise.
	*
	tests/data/test-read-dwarf/PR25042-libgdbm-clang-dwarf5.so.6.0.0.abi:
	Likewise.  *
	tests/data/test-read-dwarf/PR26261/PR26261-exe.abi: Likewise.
	* tests/data/test-read-dwarf/libtest23.so.abi: Likewise.  *
	tests/data/test-read-dwarf/libtest24-drop-fns-2.so.abi:
	Likewise.  *
	tests/data/test-read-dwarf/libtest24-drop-fns.so.abi:
	Likewise.  *
	tests/data/test-read-dwarf/test-libandroid.so.abi: Likewise.
	* tests/data/test-read-dwarf/test10-pr18818-gcc.so.abi:
	Likewise.  * tests/data/test-read-dwarf/test12-pr18844.so.abi:
	Likewise.  * tests/data/test-read-dwarf/test13-pr18894.so.abi:
	Likewise.  * tests/data/test-read-dwarf/test14-pr18893.so.abi:
	Likewise.  * tests/data/test-read-dwarf/test15-pr18892.so.abi:
	Likewise.  * tests/data/test-read-dwarf/test16-pr18904.so.abi:
	Likewise.  * tests/data/test-read-dwarf/test17-pr19027.so.abi:
	Likewise.  *
	tests/data/test-read-dwarf/test18-pr19037-libvtkRenderingLIC-6.1.so.abi:
	Likewise.  *
	tests/data/test-read-dwarf/test19-pr19023-libtcmalloc_and_profiler.so.abi:
	Likewise.  *
	tests/data/test-read-dwarf/test20-pr19025-libvtkParallelCore-6.1.so.abi:
	Likewise.  * tests/data/test-read-dwarf/test21-pr19092.so.abi:
	Likewise.  *
	tests/data/test-read-dwarf/test22-pr19097-libstdc++.so.6.0.17.so.abi:
	Likewise.  *
	tests/data/test-read-dwarf/test9-pr18818-clang.so.abi:
	Likewise.  *
	tests/data/test-read-write/test28-without-std-fns-ref.xml:
	Likewise.  *
	tests/data/test-read-write/test28-without-std-vars-ref.xml:
	Likewise.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>
2021-06-09 18:43:02 +02:00
Dodji Seketeli
ce5e4889b1 Plug leak of debug info handles
On recent elfutils where the libdw's function dwarf_getalt exists, we
don't need to try and find the alternate debug info file ourselves by
using the function dwfl_standard_find_debuginfo.  Furthermore, when we
use that function on those recent elfutils versions, we leak the elf
resources allocated in the debug info resources; we also leak the file
descriptor to access the alternate debug info sections.

More generally, we also leak debug info handles used to access debug
info when using get_soname_of_elf_file and get_type_of_elf_file.

This patch plugs those leaks.

In the first case, if the function dwarf_getalt exists, the patch just
uses it to get the alternate debug info.  Otherwise, the patch uses
the dwfl_standard_find_debuginfo function like we used to, but then it
tries hard to free the file descriptor and debuginfo memory of the
alternate debug info.

	* configure.ac: Check the presence of dwarf_getalt in libdw.  If
	it's present, define the preprocessor macro
	LIBDW_HAS_DWARF_GETALT.  Update the autoconf configuration
	summary.
	* src/abg-dwarf-reader.cc: Add config.h.
	(find_alt_debug_info_location): Factorize this out of ...
	(find_alt_debug_info): ... this function.  Use dwarf_getalt if
	present, otherwise, keep using dwfl_standard_find_debuginfo.  In
	the later case, return the file descriptor opened to access the
	alternate debug info, by parameter, so that the caller can fclose
	it.
	(read_context::alt_fd_): New data member.
	(read_context::read_context): Initialize the new alt_fd_ data
	member.
	(read_context::load_debug_info): Store the file descriptor used to
	access the alternate debug info into the new alt_fd_ data member.
	(read_context::~read_context): New desctructor.
	(get_soname_of_elf_file, get_type_of_elf_file): Free the elf
	handle.
	(read_context::load_debug_info): Be paranoid in making sure we
	never override alt_dwarf_.
	* tests/data/test-alt-dwarf-file/test0-report.txt: Adjust.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>
2016-05-22 23:20:13 +02:00
Dodji Seketeli
43c908ed15 Bug 19336 - Better handle redundantly qualified reference types
Sometimes we can see const references in DWARF.  But then, a reference
is always const, so that qualified reference is redundant.
Furthermore, having that construct make its way into the internal
representation can cause awkward diagnostics.

The DWARF reader was thus eliding such redundant qualifiers in the
function "maybe_strip_qualification".  It was doing so by stripping
the qualifier from the qualified type. So const reference, for
instance, becomes a (non-qualified) reference.  In that case, we are
turning a qualified type into a non-qualified one.

But as the accompanying problem report suggests, this can cause issues
during the DWARF parsing.  This is because a given Debug Information
Entry (DIE) of qualified type kind can be referenced elsewhere, by
another type.  That other type expects that DIE to be a qualified
type.  And libabigail's DWARF reader code enforces that.  So the
internal representation of a type resulting from a qualified type DIE
must be a qualified type itself.

So the way the function "maybe_strip_qualification" was doing the
redundancy elision was wrong.  This patch fixes that by keeping the
type qualified, but introducing a "no-op" qualifier.  Actually, the IR
already has that "no-op" qualifier: abigail::ir::qualified_type_def::CV_NONE.

So now "maybe_strip_qualification" just turns the CV_CONST qualifier
into a CV_NONE one when the former is redundant.

Now that the libabigail type system actually *has* types qualified
with this no-op qualifier, we need to handle things like printing the
name of such qualified types.  When we are printing the name of the
type for internal reasons (i.e, for type canonicalization purposes) we
need to make a difference between the name of a no-op qualified type
and the name of the underlying type of the qualified type, otherwise,
the canonicalizer wrongly considers the two types as being equal.  But
then when we are printing the name of the no-op qualified type for
diagnostics reasons, then the name is the same as the name of its
underlying unqualified type.

	* src/abg-dwarf-reader.cc (maybe_strip_qualification): Do not nuke
	the qualified type.  Rather, just turn the redundant const
	qualifier into a no-op one.
	* src/abg-comparison.cc (compute_diff_for_types): Look through
	no-op qualified types.
	* include/abg-ir.h
	(decl_base::{peek,set}_temporary_qualified_name): Declare new
	accessors.
	* src/abg-ir.cc (decl_base::priv::temporary_qualified_name_): New
	data member.
	(decl_base::{peek,set}_temporary_qualified_name): Define new
	accessors.
	(qualified_type_def::priv::{temporary_internal_name_,
	internal_name}): New data members.
	(qualified_type_def::build_name): For a no-op qualified type, the
	internal name (which contains the 'none' qualifier) is different
	from the non-internal name.
	(qualified_type_def::get_qualified_name): Handle temporary names
	and non-temporary names in two different caches.  Also handle
	internal and non-internal names in two different caches.  This
	makes four different caches.
	(qualified_name_setter::do_update): Do not touch the non-internal,
	non-temporary qualified name cache if the qualified parent name is
	empty.
	* tools/abidw.cc (main): change --check-alternate-debug-info to
	make it *not* display the name/path to the alternate debug info,
	when it's found.  Rather, only
	--check-alternate-debug-info-base-name keeps displaying the base
	name of the alternate debug info.
	* tests/data/test-alt-dwarf-file/test1-libgromacs-debug-dir/*: New
	test material.
	* tests/data/Makefile.am: Add the new test material to the build
	system.
	* tests/test-alt-dwarf-file.cc (in_out_specs): Take the new test
	input into account.
	* tests/data/test-read-dwarf/test1.abi: Adjust.
	* tests/data/test-read-dwarf/test7.so.abi: Likewise.
	* tests/data/test-read-dwarf/test10-pr18818-gcc.so.abi: Likewise.
	* tests/data/test-read-dwarf/test11-pr18828.so.abi: Likewise.
	* tests/data/test-read-dwarf/test14-pr18893.so.abi: Likewise.
	* tests/data/test-read-dwarf/test15-pr18892.so.abi: Likewise.
	* tests/data/test-read-dwarf/test16-pr18904.so.abi: Likewise.
	* tests/data/test-read-dwarf/test17-pr19027.so.abi: Likewise.
	* tests/data/test-read-dwarf/test18-pr19037-libvtkRenderingLIC-6.1.so.abi:
	Likewise.
	* tests/data/test-read-dwarf/test19-pr19023-libtcmalloc_and_profiler.so.abi:
	Likewise.
	* tests/data/test-read-dwarf/test20-pr19025-libvtkParallelCore-6.1.so.abi:
	Likewise.
	* tests/data/test-read-dwarf/test22-pr19097-libstdc++.so.6.0.17.so.abi:
	Likewise.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>
2015-12-08 14:11:22 +01:00
Dodji Seketeli
1e55a1245e Make the alt dwarf debug file *not* be a symlink
* tests/data/test-alt-dwarf-file/test0-debug-dir/.build-id/16/7088580c513b439c9ed95fe6a8b29496495f26.debug:
	Make this be a real file, no more a symlink to
	../../../test0-common-dwz.debug.
	* tests/data/test-alt-dwarf-file/test0-report.txt: Now that the
	file above is no more a symlink the message emitted by the test
	changes.  It now says that the file found is the base name of the
	real file.  So change the reference report accordingly.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>
2014-11-19 16:50:48 +01:00
Dodji Seketeli
1bd8dcf173 Make the link to the alt debug info file relative
* tests/data/test-alt-dwarf-file/test0-debug-dir/.build-id/16/7088580c513b439c9ed95fe6a8b29496495f26.debug:
	Make this link be relative.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>
2014-08-18 23:45:42 +02:00
Dodji Seketeli
7b126c03a0 Support alternate debug info sections
ABGBZ#17193
	* include/abg-dwarf-reader.h (class read_context)
	(typedef read_context_sptr, create_read_context)
	(has_alt_debug_info): Declare these.
	(read_corpus_from_elf): Declare new overload.
	* src/abg-dwarf-reader.cc (find_alt_debug_info)
	(is_die_attribute_resolved_through_gnu_ref_alt)
	(build_primary_die_parent_relations_under)
	(build_alternate_die_parent_relations_under):
	Define new static functions.
	(read_context::{alt_dwarf_,
	alt_debug_info_path_, alternate_die_decl_map_,
	alternate_die_parent_map_}): New data members.
	(read_context::{alt_dwarf, alt_debug_info_path,
	alternate_die_decl_map, associate_die_to_decl_primary,
	associate_die_to_decl_alternate, associate_die_to_decl,
	lookup_decl_from_die_offset_primary,
	lookup_decl_from_die_offset_alternate,
	lookup_decl_from_die_offset, alternate_die_parent_map}): New
	member functions.
	(read_context::load_debug_info): Painfully Get a handle on the
	alternate debug info section too.  We shouldn't have to do all
	this work; we could use the new dwarf_getalt() function from
	libdw, but we cannot as we want to support supports that predate
	that api.  When a version of elfutils gets released with that api
	though, we should conditionally use that instead.
	(build_ir_node_from_die, get_parent_die, get_scope_for_die)
	(build_namespace_decl_and_add_to_ir)
	(build_class_type_and_add_to_ir, build_qualified_type)
	(build_pointer_type_def, build_reference_type, build_typedef_type)
	(build_var_decl, build_function_decl): Take a new parameter that
	tells if the input DIE is from alternate debug info.  Adjust their
	code accordingly.
	(die_die_attribute): Take a new output parameter that tells if the
	resolved DIE is from alternate debug info.  Also take a new
	parameter that tells if the input DIE is from alternate debug info
	sections.
	(build_die_parent_relations_under): Take the DIE -> parent map to
	act upon.  Also, add a new overload that takes a flag saying if
	the DIE is from alternate debug info or not, and act upon that.
	(build_die_parent_maps): Renamed build_die_parent_map into this
	and make it build DIE -> parent DIE relationship for the alternate
	debug info file as well.
	(find_last_import_unit_point_before_die, ): Adjust to use the
	information about if the relevant DIEs are in alternate debug info
	or not.
	(build_translation_unit_and_add_to_ir): Clear the alternate DIE ->
	decl map, that is per TU just as the primary DIE -> decl map.
	Adjust to use the information about if the relevant DIEs are in
	alternate debug info or not.
	(read_debug_info_into_corpus): Build the two DIE -> DIE parent
	maps (one for the primary debug info and one for the alternate
	debug info).
	(create_read_context, has_alt_debug_info): Define new public entry
	points.
	(read_corpus_from_elf): New entry point overload that takes a
	read_context.
	* tools/bidw.cc (options::{check_alt_debug_info_path,
	show_base_name_alt_debug_info_path}): New data members.
	(display_usage): Update for the two new options
	--check-alternate-debug-info and
	check-alternate-debug-info-base-name.
	(parse_command_line): Parse the two options above.
	(main) Handle the two new options above.
	* tests/Makefile.am: Build the new runtestaltdwarf test.  Add the
	new data/test-alt-dwarf-file/* files to the build system.
	* tests/test-alt-dwarf-file.cc: New test driver.
	* tests/data/test-alt-dwarf-file/test0-common.cc: New test input
	files.
	* tests/data/test-alt-dwarf-file/libtest0-common.so: Likewise.
	* tests/data/test-alt-dwarf-file/test0.cc: Likewise.
	* tests/data/test-alt-dwarf-file/libtest0.so: Likewise.
	* tests/data/test-alt-dwarf-file/test0.h: Likewise.
	* tests/data/test-alt-dwarf-file/test0-common-dwz.debug: Likewise.
	* tests/data/test-alt-dwarf-file/test0-debug-dir/.build-id/16/7088580c513b439c9ed95fe6a8b29496495f26.debug:
	Likewise.
	* tests/data/test-alt-dwarf-file/test0-debug-dir/test0-common-dwz.debug:
	Likewise.
	* tests/data/test-read-dwarf/test1.abi: Adjust. bidw doesn't emit
	an abstract constructor/destructor anymore. It emits just the
	functions matching the cdtor symbols found in the binary.
	* tests/data/test-read-dwarf/test2.so.abi: Likewise.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>
2014-08-15 18:27:04 +02:00