When there is no .debug_addr section for some reason,
llvm-dwarfdump would print the bogus empty section name when dumping ranges
in .debug_info:
DW_AT_ranges [DW_FORM_rnglistx] (indexed (0x0) rangelist = 0x00000004
[0x0000000000000000, 0x0000000000000001) ""
[0x0000000000000000, 0x0000000000000002) "")
That happens because of the code which uses 0 (zero) as a section index as a default value.
The code should use -1ULL instead because technically 0 is a valid zero section index
in ELF and -1ULL is a special constant used that means "no section available".
This is mostly a fix for the overall correctness/safety of the code,
but a test case is provided too.
Differential revision: https://reviews.llvm.org/D55113
llvm-svn: 348115
Adding functionality to the DWARF verifier for DWARF v5 strx* forms which
index into the string offsets table.
Differential Revision: https://reviews.llvm.org/D54049
llvm-svn: 346061
Relocatable content may have overlapping ranges until the sections are
finalized. This reduces the amount of verification that is done on an object
file so that invalid errors are not raised.
llvm-svn: 345441
As was already mentioned in comments for D53364, DWARF 5
spec says about DW_LLE_startx_length:
"This is a form of bounded location description that has two unsigned ULEB operands.
The first value is an address index (into the .debug_addr section) that indicates the beginning of the address range
over which the location is valid. The second value is the length of the range. ")
Currently, the length is always parsed as U32.
Patch change the behavior to parse DW_LLE_startx_length as ULEB128 for DWARF 5
and keeps it as U32 for DWARF4+(pre-DWARF5) for compatibility.
Differential revision: https://reviews.llvm.org/D53564
llvm-svn: 345254
Using -diff and -verbose together doesn't work today. We should audit
where these two options interact and fix them. In the meantime we error
out when the user try to specify both.
llvm-svn: 345084
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
- Add fix so that all code paths that create DWARFContext
with an ObjectFile initialise the target architecture in the context
- Add an assert that the Arch is known in the Dwarf CallFrameString method
llvm-svn: 343317
Instead of indexing local variables by DIE offset, use the variable
name + the path through the lexical block tree. This makes the lookup
key consistent across duplicate abstract origins in different CUs.
llvm-svn: 342776
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
The -diff option makes it easy to diff dwarf by hiding addresses and
offsets. However not all of them were hidden, which should be fixed by
this patch.
Differential revision: https://reviews.llvm.org/D51593
llvm-svn: 341377
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
The intent is to use it for location list tables as well. Change is almost NFC with the exception
of the spelling of some strings used during dumping (all lowercase now).
Reviewer: JDevlieghere
Differential Revision: https://reviews.llvm.org/D49500
llvm-svn: 337763
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:
Both (Apple and DWARF5) implementations of the iterators had bugs which
resulted in crashes if one attempted to iterate through the accelerator
tables all the way.
For the Apple tables, the issue was that we did not clear the DataOffset
field when we reached the end, which made our iterator compare unequal
to the "end" iterator. For the Dwarf5 tables, the problem was that we
incremented the CurrentIndex pointer and then used the incremented
(possibly invalid) pointer to check whether we have reached the end of
the index list.
The reason these bugs went undetected is because their only user
(dwarfdump) only ever searched for the first match. Besides allowing us
to test this fix, changing llvm-dwarfdump --find to display all matches
seems like a good improvement (it makes the behavior consistent with the
--name option), so I change llvm-dwarfdump to do that.
The existing tests would be sufficient to test this fix with the new
llvm-dwarfdump behavior, but I add a special test that demonstrates that
the tool indeed displays multiple results. The find.test test needed to
be tweaked a bit as the tool now does not print the ".debug_info
contents" header (also consistent with how --name works).
Reviewers: JDevlieghere, aprantl, dblaikie
Subscribers: mgrang, llvm-commits
Differential Revision: https://reviews.llvm.org/D47543
llvm-svn: 333635
When requesting to dump both the parent chain and children, we used to
print the DIE more than once because we propagated the dump options to
the parent without clearing the respective flags. This commit fixes this
oversight and adds a test.
rdar://39415292
Differential revision: https://reviews.llvm.org/D47263
llvm-svn: 333350
This commit adds a color category so tools can document this option and
enables it for dwarfdump and dsymuttil.
rdar://problem/40498996
llvm-svn: 333176
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
Reviewed by: dblaikie, JDevlieghere, espindola
Differential Revision: https://reviews.llvm.org/D44560
Summary:
The .debug_line parser previously reported errors by printing to stderr and
return false. This is not particularly helpful for clients of the library code,
as it prevents them from handling the errors in a manner based on the calling
context. This change switches to using llvm::Error and callbacks to indicate
what problems were detected during parsing, and has updated clients to handle
the errors in a location-specific manner. In general, this means that they
continue to do the same thing to external users. Below, I have outlined what
the known behaviour changes are, relating to this change.
There are two levels of "errors" in the new error mechanism, to broadly
distinguish between different fail states of the parser, since not every
failure will prevent parsing of the unit, or of subsequent unit. Malformed
table errors that prevent reading the remainder of the table (reported by
returning them) and other minor issues representing problems with parsing that
do not prevent attempting to continue reading the table (reported by calling a
specified callback funciton). The only example of this currently is when the
last sequence of a unit is unterminated. However, I think it would be good to
change the handling of unrecognised opcodes to report as minor issues as well,
rather than just printing to the stream if --verbose is used (this would be a
subsequent change however).
I have substantially extended the DwarfGenerator to be able to handle
custom-crafted .debug_line sections, allowing for comprehensive unit-testing
of the parser code. For now, I am just adding unit tests to cover the basic
error reporting, and positive cases, and do not currently intend to test every
part of the parser, although the framework should be sufficient to do so at a
later point.
Known behaviour changes:
- The dump function in DWARFContext now does not attempt to read subsequent
tables when searching for a specific offset, if the unit length field of a
table before the specified offset is a reserved value.
- getOrParseLineTable now returns a useful Error if an invalid offset is
encountered, rather than simply a nullptr.
- The parse functions no longer use `WithColor::warning` directly to report
errors, allowing LLD to call its own warning function.
- The existing parse error messages have been updated to not specifically
include "warning" in their message, allowing consumers to determine what
severity the problem is.
- If the line table version field appears to have a value less than 2, an
informative error is returned, instead of just false.
- If the line table unit length field uses a reserved value, an informative
error is returned, instead of just false.
- Dumping of .debug_line.dwo sections is now implemented the same as regular
.debug_line sections.
- Verbose dumping of .debug_line[.dwo] sections now prints the prologue, if
there is a prologue error, just like non-verbose dumping.
As a helper for the generator code, I have re-added emitInt64 to the
AsmPrinter code. This previously existed, but was removed way back in r100296,
presumably because it was dead at the time.
This change also requires a change to LLD, which will be committed separately.
llvm-svn: 331971
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
In order to set breakpoints on labels and list source code around
labels, we need collect debug information for labels, i.e., label
name, the function label belong, line number in the file, and the
address label located. In order to keep these information in LLVM
IR and to allow backend to generate debug information correctly.
We create a new kind of metadata for labels, DILabel. The format
of DILabel is
!DILabel(scope: !1, name: "foo", file: !2, line: 3)
We hope to keep debug information as much as possible even the
code is optimized. So, we create a new kind of intrinsic for label
metadata to avoid the metadata is eliminated with basic block.
The intrinsic will keep existing if we keep it from optimized out.
The format of the intrinsic is
llvm.dbg.label(metadata !1)
It has only one argument, that is the DILabel metadata. The
intrinsic will follow the label immediately. Backend could get the
label metadata through the intrinsic's parameter.
We also create DIBuilder API for labels to be used by Frontend.
Frontend could use createLabel() to allocate DILabel objects, and use
insertLabel() to insert llvm.dbg.label intrinsic in LLVM IR.
Differential Revision: https://reviews.llvm.org/D45024
Patch by Hsiangkai Wang.
llvm-svn: 331841
This prevents infinite recursion in DWARFDie::findRecursively for
malformed DWARF where a DIE references itself.
This fixes PR36257.
Differential revision: https://reviews.llvm.org/D43092
llvm-svn: 331200
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:
The positions of the DwarfVersion and AddressSize arguments were
reversed, which caused parsing for dwarf opcodes which contained
address-size-dependent operands (such as DW_OP_addr). Amusingly enough,
none of the address-size asserts fired, as dwarf version was always 4,
which is a valid address size.
I ran into this when constructing weird inputs for the DWARF verifier. I
I add a test case as hand-written dwarf -- I am not sure how to trigger
this differently, as having a DW_OP_addr inside a location list is a
fairly non-standard thing to do.
Fixing this error exposed a bug in the debug_loc.dwo parser, which was
always being constructed with an address size of 0. I fix that as well
by following the pattern in the non-dwo parser of picking up the address
size from the first compile unit (which is technically not correct, but
probably good enough in practice).
Reviewers: JDevlieghere, aprantl, dblaikie
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D45324
llvm-svn: 329381
We should align the value of the field, not the overall section offset.
This distinction matters if one of the debug_names contributions is not
of size which is a multiple of four. The dwarf producers may choose to
emit rounded contributions, but they are not required to do so. In the
latter case, without this patch we would corrupt the parsing state, as
we would adjust the offset even if subsequent contributions contained
correctly rounded augmentation strings.
llvm-svn: 328796
Before this patch we were parsing the attributes as section offsets, as
that is what apple_names is doing. However, this is not correct as DWARF
v5 specifies that this attribute should use the Reference form class.
This also updates all the testcases (except the ones that deliberately
pass a different form) to use the correct form class.
llvm-svn: 328773
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
Summary:
Even though the getDIEOffset offset function was common for the two
accelerator table implementations, it was doing two different things:
for the Apple tables, it was returning the die offset relative to the
start of the section, whereas for DWARF v5 tables, it was relative to
the start of the CU.
I resolve this by renaming the function to getDIESectionOffset to make
it obvious what the function returns, and change the DWARF
implementation to return the section offset. I also keep the CU-relative
accessor, but only in the DWARF implementation (there is no way to get
this information for the Apple tables). This was not caught by existing
tests because the hand-written inputs also erroneously used section
offsets instead of CU-relative ones.
While looking at this, I noticed that the Apple implementation was not
fully correct either -- the header contains a DIEOffsetBase field, which
should be added to offsets encoded with the DW_FORM_ref*** family, but
this was not being used. This went unnoticed because all current writers
set this field to zero anyway. I fix this as well and add a hand-written
test which demonstrates the issue.
Reviewers: JDevlieghere, dblaikie
Subscribers: aprantl, llvm-commits
Differential Revision: https://reviews.llvm.org/D44202
llvm-svn: 327116
Adding verbose dumping to the recent implementation of dumping of v5 range list entries.
We're capturing the entries as is as they come in during extraction, including their file offset,
so we can dump them in more detail.
The offset table entries which are table-relative are shown as is (as in non-verbose mode)
and with the actual file offset they map to.
Reviewers: dblaikie, aprantl, jdevlieghere, jhenderson
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D43366
llvm-svn: 327059
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
Instead of only printing the CU-relative offset in non-verbose mode, it
makes more sense to only printed the resolved address. In verbose mode
we still print both.
Differential revision: https://reviews.llvm.org/D44148
rdar://33525475
llvm-svn: 326903
