DWARF v5 introduces DW_AT_call_all_calls, a subprogram attribute which
indicates that all calls (both regular and tail) within the subprogram
have call site entries. The information within these call site entries
can be used by a debugger to populate backtraces with synthetic tail
call frames.
Tail calling frames go missing in backtraces because the frame of the
caller is reused by the callee. Call site entries allow a debugger to
reconstruct a sequence of (tail) calls which led from one function to
another. This improves backtrace quality. There are limitations: tail
recursion isn't handled, variables within synthetic frames may not
survive to be inspected, etc. This approach is not novel, see:
https://gcc.gnu.org/wiki/summit2010?action=AttachFile&do=get&target=jelinek.pdf
This patch adds an IR-level flag (DIFlagAllCallsDescribed) which lowers
to DW_AT_call_all_calls. It adds the minimal amount of DWARF generation
support needed to emit standards-compliant call site entries. For easier
deployment, when the debugger tuning is LLDB, the DWARF requirement is
adjusted to v4.
Testing: Apart from check-{llvm, clang}, I built a stage2 RelWithDebInfo
clang binary. Its dSYM passed verification and grew by 1.4% compared to
the baseline. 151,879 call site entries were added.
rdar://42001377
Differential Revision: https://reviews.llvm.org/D49887
llvm-svn: 343883
This extends the verifier to catch three new errors:
* Missing DW_AT_type attributes for DW_TAG_formal_parameter,
DW_TAG_variable and DW_TAG_array_type.
* Valid references for DW_AT_type pointing to a non-type tag.
Differential revision: https://reviews.llvm.org/D52223
llvm-svn: 342713
Verify that DW_AT_specification and DW_AT_abstract_origin reference a
DIE with a compatible tag.
Differential revision: https://reviews.llvm.org/D38719
llvm-svn: 342712
It's pretty common for the verifier to dump the relevant DIE when it
finds an issue. This tends to be relatively verbose and error prone
because we have to pass the DIDumpOptions to the DIE's dump method. This
patch adds a helper function to the verifier to make this easier.
llvm-svn: 342526
According to the standard, for the .debug_names (the "dwarf accelerator
tables"):
> If a subprogram or inlined subroutine is included, and has a
> DW_AT_linkage_name attribute, there will be an additional index entry
> for the linkage name.
For Swift we generate DW_structure_types with a linkage name and the
verifier was incorrectly rejecting this. This patch fixes that by only
considering the linkage name in those particular cases. The test is the
"reduced" debug info of the failing swift test on swift.org.
Differential revision: https://reviews.llvm.org/D51420
llvm-svn: 341311
We don't expect module names to be present in the index. This patch adds
DW_TAG_module to the blacklist.
Differential revision: https://reviews.llvm.org/D50237
llvm-svn: 338878
This is patch 3 of 4 NFC refactorings to handle type units and compile
units more consistently and with less concern about the object-file
section that they came from.
Patch 3 simply renames DWARFUnitSection to DWARFUnitVector, as the
object-file section of a unit is nearly irrelevant now.
Differential Revision: https://reviews.llvm.org/D49743
llvm-svn: 338632
This is patch 1 of 4 NFC refactorings to handle type units and compile
units more consistently and with less concern about the object-file
section that they came from.
Patch 1 replaces the templated DWARFUnitSection with a non-templated
version. That is, instead of being a SmallVector of pointers to a
specific unit kind, it is not a SmallVector of pointers to the base
class for both type and compile units. Virtual methods are magic.
Differential Revision: https://reviews.llvm.org/D49741
llvm-svn: 338628
Errors found processing the DW_AT_ranges attribute are propagated by lower level
routines and reported by their callers.
Reviewer: JDevlieghere
Differential Revision: https://reviews.llvm.org/D48344
llvm-svn: 335188
Summary:
This method was not correct for entries in DWO files as it assumed it
could just add up the CU and DIE offsets to get the absolute DIE offset.
This is not correct for the DWO files, as here the CU offset will
reference the skeleton unit, whereas the DIE offset will be the offset
in the full unit in the DWO file.
Unfortunately, this means that we are not able to determine the absolute
DIE offset using the information in the .debug_names section alone,
which means we have to offload some of this work to the users of this
class.
To demonstrate how this can be done, I've added/fixed the ability to
lookup entries using accelerator tables in DWO files in llvm-dwarfdump.
To make this happen, I've needed to make two extra changes in other
classes:
- made the DWARFContext method to lookup a CU based on the section
offset public. I've needed this functionality to lookup a CU, and this
seems like a useful thing in general.
- made DWARFUnit::getDWOId call extractDIEsIfNeeded. Before this, the
DWOId was filled in only if the root DIE happened to be parsed
before we called the accessor. Since the lazy parsing is supposed to
happen under the hood, calling extractDIEsIfNeeded seems appropriate.
Reviewers: JDevlieghere, aprantl, dblaikie
Subscribers: mgrang, llvm-commits
Differential Revision: https://reviews.llvm.org/D48009
llvm-svn: 334578
Summary:
Back when we were introducing the DWARF v5 name index, there was a
short discussion whether we shouldn't have a nicer api for iterating
over the index. At that time, I did not find it necessary since the
iteration over names was done only from within the index itself (and I
figured the internal implementation can deal with a slightly rough
interface).
However, now I ran into a use for this kind of API in LLDB (for finding
all names matching a regular expression), so it looked like a nice
opportunity to introduce one. To make the API more useful, I've made the
NameTableEntry class a bit smarter: it now stores the string section
reference (so it can return its name) and its position in the name index
(mainly useful for dumping/logging).
I also convert the internal users to use the new API, which also gives
test coverage for the added code.
Reviewers: JDevlieghere, aprantl, dblaikie
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D47590
llvm-svn: 333738
When printing an error for an invalid address range in a DIE, we used to
print the child above the parent, which is counter intuitive. This patch
reverses the order and indents the child to mimic the way we print the
debug info section.
llvm-svn: 333006
This is a resubmit of r331868 (D46583), which was reverted due to
failures on the PS4 bot.
These have been resolved with r332246/D46748.
llvm-svn: 332349
Extract information related to a "unit header" from DWARFUnit into a
new DWARFUnitHeader class, and add a DWARFUnit member for the header.
This is one step in the direction of allowing type units in the
.debug_info section for DWARF v5.
Differential Revision: https://reviews.llvm.org/D46707
llvm-svn: 332289
Summary:
If we are not emitting a linkage name in the .debug_info sections, we
should not add it into the index either. This makes sure our index is
consistent with the actual debug info.
I am also explicitly setting the --dwarf-linkage-names=All in the
name-collsions test as that one would now fail on targets where this
defaults to "Abstract" (in fact, it would have failed already if there
wasn't a bug in the DWARF verifier, which I fix as well).
Reviewers: probinson, aprantl, JDevlieghere
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D46748
llvm-svn: 332246
The new verifier check has found an error in the
debug-names-name-collisions.ll test on the PS4 bot:
error: Name Index @ 0x0: Entry @ 0xdc: mismatched Name of DIE @ 0x23: index - _ZN3foo3fooE; debug_info - foo.
Reverting while I investigate whether this is a bug in the verifier or
the generator.
This reverts commit r331868.
llvm-svn: 331869
Summary:
This patch implements a check which makes sure all entries required by
the DWARF v5 specification are present in the Name Index. The algorithm
tries to follow the wording of Section 6.1.1.1 of the spec as closely as
possible.
The main deviation from it is that instead of a whitelist-based approach
in the spec "The name index must contain an entry for each debugging
information entry that defines a named subprogram, label, variable,
type, or namespace" I chose a blacklist-based one, where I consider
everything to be "in" and then remove the entries that don't make sense.
I did this because it has more potential for catching interesting cases
and the above is a bit vague (it uses plain words like "variable" and
"subprogram", but the rest of the section speaks about specific TAGs).
This approach has raised some interesting questions, the main one being
whether enumerator values should be indexed. The consensus seems to be
that they should, although it does not follow from section 6.1.1.1.
For the time being I made the verifier ignore these, as LLVM does not do
this yet, and I wanted to get a clean run when verifying generated debug
info.
Another interesting case was the DW_TAG_imported_declaration. It was not
immediately clear to me whether this should go in or not, but currently
it is not indexed, and (unlike the enumerators) in does not seem to cause
problems for LLDB, so I've also ignored it.
Reviewers: JDevlieghere, aprantl, dblaikie
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D46583
llvm-svn: 331868
Summary:
This patch add checks to verify that the information in the name index
entries is consistent with the debug_info section. Specifically, we
check that entries point to valid DIEs, and their names, tags, and
compile units match the information in the debug_info sections.
These checks are only run if the previous checks did not find any errors
in the name index headers. Attempting to proceed with the checks anyway
would likely produce a lot of spurious errors and the verification code
would need to be very careful to avoid crashing.
I also add a couple of more checks to the abbreviation-validation code
to verify that some attributes are always present (an index without a
DW_IDX_die_offset attribute is fairly useless).
The entry verification works only on indexes without any type units - I
haven't attempted to extend it to type units, as we don't even have a
DWARF v5-compatible type unit generator at the moment.
Reviewers: JDevlieghere, aprantl, dblaikie
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45323
llvm-svn: 329392
Summary:
This commit adds checks of the abbreviation table in a DWARF v5 Name
Index. The most interesting/useful check is the one which checks that
each index attributes is encoded using the correct form class, but it
also checks for the more obvious errors like unknown
forms/tags/attributes and duplicated attributes.
Reviewers: JDevlieghere, aprantl, dblaikie
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D44736
llvm-svn: 328202
Summary:
This patch adds more checks to the .debug_names validator. Specifically,
they check for:
- buckets claiming to be non-empty but pointing to mismatched hashes
(most consumers would interpret this as an empty bucket, but it
questionable whether the generator meant that)
- hashes that are not reachable from any bucket
- names with incorrect hashes
Together, these checks ensure that any name in the index can be reached
through the hash table using the regular lookup algorithm. We also warn
if we encounter a name index without a hash table.
Reviewers: JDevlieghere, aprantl, dblaikie
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D44433
llvm-svn: 327699
Move the DWARF syntax highlighting into support. This has several
advantages, most notably that this makes the WithColor RAII wrapper
available outside libDebugInfo. Furthermore, several projects all have
their own code for handling colored output. This provides a place to
centralize it.
Differential revision: https://reviews.llvm.org/D44215
llvm-svn: 327108
Summary:
This patch adds basic .debug_names verification capabilities to the
DWARF verifier. Right now, it checks that the headers and abbreviation
tables of the individual name indexes can be parsed correctly, it
verifies the buckets table and the cross-checks the CU lists for
consistency. I intend to add further checks in follow-up patches.
Reviewers: JDevlieghere, aprantl, probinson, dblaikie
Subscribers: vleschuk, echristo, clayborg, llvm-commits
Differential Revision: https://reviews.llvm.org/D44211
llvm-svn: 327011
Verifying any DWARF file that is optimized and contains at least one tag
with a DW_AT_location with a location list offset as a
DW_AT_form_dataXXX results in dwarfdump spuriously claiming that the
location list is invalid.
Differential revision: https://reviews.llvm.org/D40199
llvm-svn: 325430
This form is like DW_FORM_strp, but points to .debug_line_str instead
of .debug_str as the string section. It's intended to be used from
the line-table header, and allows string-pooling of directory and
filenames across compilation units.
Differential Revision: https://reviews.llvm.org/D42553
llvm-svn: 323476
This frees up the first name to be used as an base class for the
apple table and the dwarf5 .debug_names accel table. The rename was
split off from D42297 (adding of debug_names support), which is still
under review.
llvm-svn: 323113
This fixes a bug where the verifier was complaining about empty
accelerator tables. When the table is empty, its size is not a valid
offset as it points after the end of the section.
This patch also makes the extractor return llvm:Error instead of bool
for better error reporting in the verifier.
Differential revision: https://reviews.llvm.org/D41063
rdar://35932007
llvm-svn: 320399
Patch improves next things:
* Fixes assert/crash in getOpDesc when giving it a invalid expression op code.
* DWARFExpression::print() called DWARFExpression::Operation::getEndOffset() which
returned and used uninitialized field EndOffset. Patch fixes that.
* Teaches verifier to verify DW_AT_location and error out on broken expressions.
Differential revision: https://reviews.llvm.org/D39294
llvm-svn: 316756
This patch adds printing for DW_AT_type DIEs like it is already the case
for DW_AT_specification DIEs. This is a rather naive approach and only a
start. We should have pretty printers for different languages.
Recommit after being reverted in r315299.
Differential revision: https://reviews.llvm.org/D36993
llvm-svn: 315316
This patch adds two new verifiers:
- It checks that the root DIE of a CU is actually a valid unit DIE.
(based on its tag)
- For DWARF5 which contains a unit type int he CU header, it checks that
this matches the type of the unit DIE.
Differential revision: https://reviews.llvm.org/D38453
llvm-svn: 315121
This implement the insertion operator for DWARF address ranges so they
are consistently printed as [LowPC, HighPC).
While a dump method might have felt more consistent, it is used
exclusively for printing error messages in the verifier and never used
for actual dumping. Hence this approach is more intuitive and creates
less clutter at the call sites.
Differential revision: https://reviews.llvm.org/D38395
llvm-svn: 314523
This patch introduces 3 helper functions: error(), warn() and note() to
make printing during verification more consistent. When supported, the
respective prefixes are printed in color using the same color scheme as
clang.
Differential revision: https://reviews.llvm.org/D38368
llvm-svn: 314498
This patch adds a check to the DWARF verifier to detect CUs without a
unit DIE.
Differential revision: https://reviews.llvm.org/D38363
llvm-svn: 314426
This patch implements the Darwin dwarfdump option --recurse-depth=<N>,
which limits the recursion depth when selectively printing DIEs at an
offset.
Differential Revision: https://reviews.llvm.org/D38064
llvm-svn: 313778
This patch started as an attempt to rebase Greg's differential (D32821).
The result is both quite similar and different at the same time. It adds
the following checks:
- Verify that all address ranges in a DIE are valid.
- Verify that no ranges within the DIE overlap.
- Verify that no ranges overlap with the ranges of a sibling.
- Verify that children are completely contained in its (direct)
parent's address range. (unless both are subprograms)
Differential revision: https://reviews.llvm.org/D37696
llvm-svn: 313255
This patch started as an attempt to rebase Greg's differential (D32821).
The result is both quite similar and different at the same time. It adds
the following checks:
- Verify that all address ranges in a DIE are valid.
- Verify that no ranges within the DIE overlap.
- Verify that no ranges overlap with the ranges of a sibling.
- Verify that children are completely contained in its (direct)
parent's address range. (unless both are subprograms)
Differential revision: https://reviews.llvm.org/D37696
llvm-svn: 313250
This patches renames "brief" to "verbose" in de DIDumpOptions and
inverts the logic to match the new behavior where brief is the default.
Changing the default value uncovered some bugs related to the
DIDumpOptions not being propagated and have been fixed as well.
Differential revision: https://reviews.llvm.org/D37745
llvm-svn: 313139
This patch adds prologue verification, which is already present in
Apple's dwarfdump. It checks for invalid directory indices and warns
about duplicate file paths.
Differential revision: https://reviews.llvm.org/D37511
llvm-svn: 312782
These lead to tests failing spuriously as the values after being rendered to a
string were incorrect.
Reviewers: clayborg
Differential Revision: https://reviews.llvm.org/D36319
llvm-svn: 310262
SUMMARY
This patch adds a verification check on the abbreviation declarations in the .debug_abbrev section.
The check makes sure that no abbreviation declaration has more than one attributes with the same name.
Differential Revision: https://reviews.llvm.org/D35643
llvm-svn: 308579
This changes DwarfContext to delegate to DwarfObject instead of having
pure virtual methods.
With this DwarfContextInMemory is replaced with an implementation of
DwarfObject that is local to a .cpp file.
llvm-svn: 308543
Summary:
This patch modifies the handleDebugInfo() function so that we verify the contents of each unit
in the .debug_info section only if its header has been successfully verified.
This change will allow for more/different verification checks depending on the type of the unit since from
dwarf5, the .debug_info section may consist of different types of units.
Subscribers: aprantl
Differential Revision: https://reviews.llvm.org/D35521
llvm-svn: 308245
This patch adds verification checks for the unit header chain in the .debug_info section.
Specifically, for each unit in the .debug_info section, the verifier checks that:
The unit length is valid (i.e. the unit can actually fit in the .debug_info section)
The dwarf version of the unit is valid
The address size is valid (4 or 8)
The unit type (if the unit is in dwarf5) is valid
The debug_abbrev_offset is valid
llvm-svn: 307975
This patch verifies the number of atoms, the validity of the form for each atom, as well as the validity of the
hashdata. For hashdata, we're verifying that the hashdata offset is correct and that the offset in the .debug_info for
each DIE in the hashdata is also valid.
llvm-svn: 306735
Requires callers to directly associate relocations with a DataExtractor
used to read data from a DWARF section, which helps a callee not make
assumptions about which section it is reading.
This is the next step in reducing DWARFFormValue's dependence on DWARFUnit.
Differential Revision: https://reviews.llvm.org/D34704
llvm-svn: 306699
The verifier should not output any message in such a case.
Added test case with no .apple_name section in the file to verify new functionality.
Made existing test case more specific.
llvm-svn: 305597
This patch adds code which verifies that each bucket in the .apple_names
accelerator table is either empty or has a valid hash index.
Differential Revision: https://reviews.llvm.org/D34177
llvm-svn: 305344
There is no other explanation about why this only started happening
now, even though it crashes on old code (supposedly reachable from
here).
The only common factor between the failing bots is that they use GCC
(4.9 and 5.3) to compile Clang, while the others use Clang 3.8, but the
failure is while building the tests, as an assertion, on Clang.
Commenting it out for now in hope the bots will go back green, but we
should keep looking for the real cause, and update bugzilla.
llvm-svn: 302520
Adrian requested that we break things down to make things clean in the DWARFVerifier. This patch breaks everything down into nice individual functions and cleans up the code quite a bit and prepares us for the next round of verifiers.
Differential Revision: https://reviews.llvm.org/D32812
llvm-svn: 302062
Adrian requested we create a DWARFVerifier.cpp file to contain all of the DWARF verification stuff. This change simply moves the functionality over into DWARFVerifier.h and DWARFVerifier.cpp, renames the DWARFVerifier methods to start with lower case, and switches DWARFContext.cpp over to using the new functionality.
Differential Revision: https://reviews.llvm.org/D32809
llvm-svn: 302044
David Bolvansky