Fourth of 5 small patches to fix various breakpad issues found
while testing dump_syms on DWARF v5 in ChromeOS.
Dwarfv5 adds many new Type Unit sections to debug information. Since
these only contain type information, they are of no interest to
dump_syms. This CL gets dump_syms to skip trying to process the
type unit sections. Without this CL, dump_syms takes ~ 3 hours to
process the DWARF v5 Chrome binary. With this CL, dump_syms takes
~ 8 minutes to process the DWARF v5 Chrome binary (about the same
time as it takes for DWARF v4).
This CL also adds a test case to verify that type units are being
skipped.
Change-Id: Ie0bb2d675718f7041b8e9b3186ed44f80a3ad39c
Reviewed-on: https://chromium-review.googlesource.com/c/breakpad/breakpad/+/2634549
Reviewed-by: Sterling Augustine <saugustine@google.com>
Second of 5 small patches to fix various breakpad issues found
while testing dump_syms on DWARF v5 in ChromeOS.
This patch adds code to properly find & parse the
DW_AT_str_offsets_base attribute, and use it to handle strings
of the forms DW_FORM_strx, DW_FORM_strx1..DW_FORM_strx4 This is the
largest of the DWARF5 fixes. It also includes a unittest to test
using a string offset.
Change-Id: I5d1def862d9d91cae4b2853578441e04ea85449d
Reviewed-on: https://chromium-review.googlesource.com/c/breakpad/breakpad/+/2634547
Reviewed-by: Sterling Augustine <saugustine@google.com>
Most of this is simple, "Read the form, get the data, then
call ProcessAttribute."
Handling DW_FORM_implcit_const is a little trickier, as it
is the only form that stores its value inline in the abbrev
table itself. Add a test for that.
Print errors for supplementary object files.
Change-Id: I0999b039848bded1891998a866e5059acd538a09
Reviewed-on: https://chromium-review.googlesource.com/c/breakpad/breakpad/+/2446627
Reviewed-by: Joshua Peraza <jperaza@chromium.org>
This is a big change. dwarf5 range lists are quite a bit more complicated
than dwarf 4 range lists, both in the contextual information required, and
in their own representation and interpretation.
The big design choice here is how to pass the CU information all the
way down to the reader. I chose a structure, because otherwise the
parameter list gets very long and error prone (and has to be passed
down several levels). This structure could be made a parto of the CU
context itself, or the range handler, so it wouldn't have to be
separately assembled at range-list read time, but both of those
solutions get even more invasive, and harder to follow.
I've tried to figure out how to break this into smaller changes, but it
affects nearly everything that has to do with a compilation unit's
own addresses and when decisions must be made about how to read them.
Dependency injection will do that to you.
It does add tests for range list reading, which did not exist before.
Change-Id: I923b9a2c3379a0f52609bc05310097de5cbb7227
Reviewed-on: https://chromium-review.googlesource.com/c/breakpad/breakpad/+/2446635
Reviewed-by: Joshua Peraza <jperaza@chromium.org>
Newer gcc versions default to -Werror=narrowing when using newer C++
standards (which we do). This causes issues when we try to stuff a
value like 0xea into a char -- the value is out of range for signed
char bytes. That's when gcc throws an error:
.../bytereader_unittest.cc: In member function 'virtual void Reader_DW_EH_PE_absptr4_Test::TestBody()':
.../bytereader_unittest.cc:400:55: error: narrowing conversion of '234' from 'int' to 'char' inside { } [-Wnarrowing]
BUG=chromium:579384
TEST=`make check` passes
R=mark@chromium.org
Review URL: https://codereview.chromium.org/1605153004 .
This patch allows Breakpad's DWARF reader to at least read or skip
attributes using the new forms defined in version 4 of the DWARF
specification, instead of crashing.
Attributes encoded using DW_FORM_flag_present, DW_FORM_sec_offset, and
DW_FORM_exprloc should work fine now. However, compilation units using
DW_FORM_ref_sig8 to refer to types in .debug_types will need further work
to support. (GCC 4.6.2 does not emit .debug_types sections.)
Specifically:
- dwarf2reader::DwarfForm gets new values.
- dwarf2reader::Dwarf2Handler and dwarf2reader::DIEHandler get new handler
methods, named ProcessAttributeSignature, for DW_FORM_ref_sig8 attributes.
- dwarf2reader::CompilationUnit reads DW_FORM_ref_sig8 attributes, and
passes them to ProcessAttributeSignature. It also gets support for
DW_FORM_sec_offset, DW_FORM_exprloc, and DW_FORM_flag_present, using the
existing appropriate ProcessAttribute* methods.
- dwarf2reader::DIEDispatcher passes through ProcessAttributeSignature
attributes to its DIEHandler.
- Unit tests are updated.
a=jimb, r=ted.mielczarek
Review URL: http://breakpad.appspot.com/343003/
git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@912 4c0a9323-5329-0410-9bdc-e9ce6186880e
This is really incomplete --- it's just what's needed to get started
testing support for the DWARF 4 attribute forms.
git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@910 4c0a9323-5329-0410-9bdc-e9ce6186880e
