I have made the DW_FORM_ref4 relative. One could also use relocated
DW_FORM_ref_addr instead.
Tested with:
echo 'void f(){}'|clang -o 1.o -c -Wall -g -x c -;./bin/clang -o 1 1.o ../llvm-monorepo/lldb/test/Shell/SymbolFile/DWARF/DW_TAG_GNU_call_site-DW_AT_low_pc.s;./bin/lldb --no-lldbinit ./1 -o r -o 'p p' -o exit
Summary:
This effectively reverts r188124, which added code to handle
(DW_AT_)declarations of structures with some kinds of children as
definitions. The commit message claims this is a workaround for some
kind of debug info produced by gcc. However, it does not go into
specifics, so it's hard to reproduce or verify that this is indeed still a
problem.
Having this code is definitely a problem though, because it mistakenly
declares incomplete dwarf declarations to be complete. Both clang (with
-flimit-debug-info) and gcc (by default) generate DW_AT_declarations of
structs with children. This happens when full debug info for a class is
not emitted in a given compile unit (e.g. because of vtable homing), but
the class has inline methods which are used in the given compile unit.
In that case, the compilers emit a DW_AT_declaration of a class, but
add a DW_TAG_subprogram child to it to describe the inlined instance of
the method.
Even though the class tag has some children, it definitely does not
contain enough information to construct a full class definition (most
notably, it lacks any members). Keeping the class as incomplete allows
us to search for a real definition in other modules, helping the
-flimit-debug-info flow. And in case the definition is not found we can
display a error message saying that, instead of just showing an empty
struct.
Reviewers: clayborg, aprantl, JDevlieghere, shafik
Subscribers: lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D83302
Summary:
With D81784, lld has started debug info resolving relocations to
garbage-collected symbols as -1 (instead of relocation addend). For an
unaware consumer this generated sequences which seemingly wrap the
address space -- their first entry was 0xfffff, but all other entries
were low numbers.
Lldb stores line sequences concatenated into one large vector, sorted by
the first entry, and searched with std::lower_bound. This resulted in
the low-value entries being placed at the end of the vector, which
utterly confused the lower_bound algorithm, and caused it to not find a
match. (Previously, these sequences would be at the start of the vector,
and normally would contain addresses that are far smaller than any real
address we want to look up, so std::lower_bound was fine.)
This patch makes lldb ignore these kinds of sequences completely. It
does that by changing the construction algorithm from iterating over the
rows (as parsed by llvm), to iterating over the sequences. This is
important because the llvm parsed performs validity checks when
constructing the sequence array, whereas the row array contains raw
data.
Reviewers: JDevlieghere, MaskRay
Differential Revision: https://reviews.llvm.org/D83957
With -flimit-debug-info, we can have a definition of a class, but no
definition for some of its members. This extends the same logic we were
using for incomplete base classes to cover incomplete members too.
Test forward-declarations.s is removed as it is no longer applicable --
we don't warn anymore when encountering incomplete members as they could
be completed elsewhere. New checks added to TestLimitDebugInfo cover the
handling of incomplete members more thoroughly.
This complements the existing TestLimitDebugInfo.py, which tests this
scenario more comprehensively, but is not able to run on all hosts.
Specifically, it's hard to trigger this code from windows because clang
tries hard to ensure that debug info for types marked with
__declspec(dllexport) is emitted even under -flimit-debug-info (and
dllexport is needed to use a type across shared libraries).
This assembly-based test serves two purposes:
- it tests that -flimit-debug-info code path works for windows binaries
(even though the aforementioned feature means its less likely to be
used there)
- it gives basic test coverage for the -flimit-debug-info handling code
when running the test suite on windows hosts.
D80519 <https://reviews.llvm.org/D80519>
added support for `DW_TAG_GNU_call_site` but
Bug 45886 <https://bugs.llvm.org/show_bug.cgi?id=45886>
found one case did not work.
There is:
0x000000b1: DW_TAG_GNU_call_site
DW_AT_low_pc (0x000000000040111e)
DW_AT_abstract_origin (0x000000cc "a")
...
0x000000cc: DW_TAG_subprogram
DW_AT_name ("a")
DW_AT_prototyped (true)
DW_AT_low_pc (0x0000000000401109)
^^^^^^^^^^^^ - here it did overwrite the 'low_pc' variable containing value 0x40111e we wanted
DW_AT_high_pc (0x0000000000401114)
DW_AT_frame_base (DW_OP_call_frame_cfa)
DW_AT_GNU_all_call_sites (true)
DW_TAG_GNU_call_site attributes order as produced by GCC:
0x000000b1: DW_TAG_GNU_call_site
DW_AT_low_pc (0x000000000040111e)
DW_AT_abstract_origin (0x000000cc "a")
clang produces the attributes in opposite order:
0x00000064: DW_TAG_GNU_call_site
DW_AT_abstract_origin (0x0000002a "a")
DW_AT_low_pc (0x0000000000401146)
Differential Revision: https://reviews.llvm.org/D81334
Previously, we were simply ignoring them and continuing the evaluation.
This behavior does not seem useful, because the resulting value will
most likely be completely bogus.
Summary:
For ObjCInterfaceDecls, LLDB iterates over the `methods` of the interface in FindExternalVisibleDeclsByName
since commit ef423a3ba5 .
However, when LLDB calls `oid->methods()` in that function, Clang will pull in all declarations in the current
DeclContext from the current ExternalASTSource (which is again, `ClangExternalASTSourceCallbacks`). The
reason for that is that `methods()` is just a wrapper for `decls()` which is supposed to provide a list of *all*
(both currently loaded and external) decls in the DeclContext.
However, `ClangExternalASTSourceCallbacks::FindExternalLexicalDecls` doesn't implement support for ObjCInterfaceDecl,
so we don't actually add any declarations and just mark the ObjCInterfaceDecl as having no ExternalLexicalStorage.
As LLDB uses the ExternalLexicalStorage to see if it can complete a type with the ExternalASTSource, this causes
that LLDB thinks our class can't be completed any further by the ExternalASTSource
and will from on no longer make any CompleteType/FindExternalLexicalDecls calls to that decl. This essentially
renders those types unusable in the expression parser as they will always be considered incomplete.
This patch just changes the call to `methods` (which is just a `decls()` wrapper), to some ad-hoc `noload_methods`
call which is wrapping `noload_decls()`. `noload_decls()` won't trigger any calls to the ExternalASTSource, so
this prevents that ExternalLexicalStorage will be set to false.
The test for this is just adding a method to an ObjC interface. Before this patch, this unset the ExternalLexicalStorage
flag and put the interface into the state described above.
In a normal user session this situation was triggered by setting a breakpoint in a method of some ObjC class. This
caused LLDB to create the MethodDecl for that specific method and put it into the the ObjCInterfaceDecl.
Also `ObjCLanguageRuntime::LookupInCompleteClassCache` needs to be unable to resolve the type do
an actual definition when the breakpoint is set (I'm not sure how exactly this can happen, but we just
found no Type instance that had the `TypePayloadClang::IsCompleteObjCClass` flag set in its payload in
the situation where this happens. This however doesn't seem to be a regression as logic wasn't changed
from what I can see).
The module-ownership.mm test had to be changed as the only reason why the ObjC interface in that test had
it's ExternalLexicalStorage flag set to false was because of this unintended side effect. What actually happens
in the test is that ExternalLexicalStorage is first set to false in `DWARFASTParserClang::CompleteTypeFromDWARF`
when we try to complete the `SomeClass` interface, but is then the flag is set back to true once we add
the last ivar of `SomeClass` (see `SetMemberOwningModule` in `TypeSystemClang.cpp` which is called
when we add the ivar). I'll fix the code for that in a follow-up patch.
I think some of the code here needs some rethinking. LLDB and Clang shouldn't infer anything about the ExternalASTSource
and its ability to complete the current type form the `ExternalLexicalStorage` flag. We probably should
also actually provide any declarations when we get asked for the lexical decls of an ObjCInterfaceDecl. But both of those
changes are bigger (and most likely would cause us to eagerly complete more types), so those will be follow up patches
and this patch just brings us back to the state before commit ef423a3ba5 .
Fixes rdar://63584164
Reviewers: aprantl, friss, shafik
Reviewed By: aprantl, shafik
Subscribers: arphaman, abidh, JDevlieghere
Differential Revision: https://reviews.llvm.org/D80556
Summary:
The D programming language has 'char', 'wchar', and 'dchar' as base types,
which are defined as UTF-8, UTF-16, and UTF-32, respectively.
It also has type constructors (e.g. 'const' and 'immutable'),
that leads to D compilers emitting DW_TAG_base_type with DW_ATE_UTF
and name 'char', 'immutable(wchar)', 'const(char)', etc...
Before this patch, DW_ATE_UTF would only recognize types that
followed the C/C++ naming, and emit an error message for the rest, e.g.:
```
error: need to add support for DW_TAG_base_type 'immutable(char)'
encoded with DW_ATE = 0x10, bit_size = 8
```
The code was changed to check the byte size first,
then fall back to the old name-based check.
Reviewers: clayborg, labath
Reviewed By: labath
Subscribers: labath, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D79559
The relevant output FileCheck is scanning in this test is as follows:
CXXRecordDecl 0x7f96cf8239c8 <<invalid sloc>> <invalid sloc> imported in A.B <undeserialized declarations> struct definition
<<DefinitionData boilerplate>>
`-FieldDecl 0x7f96cf823b90 <<invalid sloc>> <invalid sloc> imported in A.B anon_field_b 'int'
(anonymous struct)
CXXRecordDecl 0x7f96cf823be8 <<invalid sloc>> <invalid sloc> imported in A.B struct
Before 710fa2c4ee this test was passing by
accident as it had a -DAG suffix in the checks changed by this patch,
causing FileCheck to first match the last line of the output above
(instead of the first one), and then finding the FieldDecl above.
When I removed the -DAG suffix, FileCheck actually enforced the ordering
and started failing as the FieldDecl comes before the CXXRecordDecl match
we get.
This patch fixes the CXXRecordDecl check to find the first line of the output
above which caused FileCheck to also find the FieldDecl that follows. Also
gives the FieldDecl a more unique name to make name collisions less likely.
This test was generating the following false-positive warning when being compiled:
warning: class 'SomeClass' defined without specifying a base class [-Wobjc-root-class]
The current test is checking both the anonymous structs and the template
specializations in one FileCheck run, but the anonymous struct line can
partially match the AST dump of a template specialization, causing that
FileCheck won't match that same line later against the template specialization
check and incorrectly fails on that check. This only happens when the
template specialization node somehow ends up before the anonymous struct node.
This patch just puts the checks for the anonymous structs in their own FileCheck
run to prevent them from partially matching any other record decl.
Fixes rdar://62997926
We have the option to stop running commands in batch mode when an error
occurs. When that happens we should exit the driver with a non-zero exit
code.
Differential revision: https://reviews.llvm.org/D78825
Summary:
This was originally commented out as it broke the data-formatter-stl/libcxx/
tests. However this was fixed by commit ef423a3ba5
(Add Objective-C property accessors loaded from Clang module DWARF to lookup)
which sets the HasExternalVisibleStorage flag for the template specializations.
Reviewers: aprantl
Reviewed By: aprantl
Subscribers: abidh, JDevlieghere
Differential Revision: https://reviews.llvm.org/D79168
The cause of this crash is relatively simple -- we are using a
SymbolFileDWARFDwo to parse a (skeleton) dwarf unit. This cause the
CompileUnit to be created with the wrong ID, which later triggers an
assertion in SymbolFile::SetCompileUnitAtIndex. The fix is also simple
-- ensure we use the right symbol file for parsing.
However, a fairly elaborate setup is needed trigger this bug, because
ParseCompileUnit is normally called very early on (and with the right
symbol file object) during the process of accessing a compile unit.
The only way this can be triggered is if the DWARF unit is
"accidentally" pulled into scope during expression evaluation
This can happen if the "this" object used for the context of an
expression is in a namespace, and that namespace is also present in
other compile units
The included test recreates this setup.
This patch fixes a bug when synthesizing an ObjC property from
-gmodules debug info. Because the method declaration that is injected
via the non-modular property implementation is not added to the
ObjCInterfaceDecl's lookup pointer, a second copy of the accessor
would be generated when processing the ObjCPropertyDecl. This can be
avoided by finding the existing method decl in
ClangExternalASTSourceCallbacks::FindExternalVisibleDeclsByName() and
adding it to the LookupPtr.
Differential Revision: https://reviews.llvm.org/D78333
Summary:
The code in DWARFCompileUnit::BuildAddressRangeTable tries hard to avoid
relying on DW_AT_low/high_pc for compile unit range information, and
this logic is a big cause of llvm/lldb divergence in the lowest layers
of dwarf parsing code.
The implicit assumption in that code is that this information (as opposed to
DW_AT_ranges) is unreliable. However, I have not been able to verify
that assumption. It is definitely not true for all present-day
compilers (gcc, clang, icc), and it was also not the case for the
historic compilers that I have been able to get a hold of (thanks Matt
Godbolt).
All compiler included in my research either produced correct
DW_AT_ranges or .debug_aranges entries, or they produced no DW_AT_hi/lo
pc at all. The detailed findings are:
- gcc >= 4.4: produces DW_AT_ranges and .debug_aranges
- 4.1 <= gcc < 4.4: no DW_AT_ranges, no DW_AT_high_pc, .debug_aranges
present. The upper version range here is uncertain as godbolt.org does
not have intermediate versions.
- gcc < 4.1: no versions on godbolt.org
- clang >= 3.5: produces DW_AT_ranges, and (optionally) .debug_aranges
- 3.4 <= clang < 3.5: no DW_AT_ranges, no DW_AT_high_pc, .debug_aranges
present.
- clang <= 3.3: no DW_AT_ranges, no DW_AT_high_pc, no .debug_aranges
- icc >= 16.0.1: produces DW_AT_ranges
- icc < 16.0.1: no functional versions on godbolt.org (some are present
but fail to compile)
Based on this analysis, I believe it is safe to start trusting
DW_AT_low/high_pc information in dwarf as well as remove the code for
manually reconstructing range information by traversing the DIE
structure, and just keep the line table fallback. The only compilers
where this will change behavior are pre-3.4 clangs, which are almost 7
years old now. However, the functionality should remain unchanged
because we will be able to reconstruct this information from the line
table, which seems to be needed for some line-tables-only scenarios
anyway (haven't researched this too much, but at least some compilers
seem to emit DW_AT_ranges even in these situations).
In addition, benchmarks showed that for these compilers computing the
ranges via line tables is noticably faster than doing so via the DIE
tree.
Other advantages include simplifying the code base, removing some
untested code (the only test changes are recent tests with overly
reduced synthetic dwarf), and increasing llvm convergence.
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D78489
This patch threads an lldb::DescriptionLevel through the typesystem to
allow dumping the full Clang AST (level=verbose) of any lldb::Type in
addition to the human-readable source description (default
level=full). This type dumping interface is currently not exposed
through the SBAPI.
The application is to let lldb-test dump the clang AST of search
results. I need this to test lazy type completion of clang types in
subsequent patches.
Differential Revision: https://reviews.llvm.org/D78329
Originally committed as 416fa7720e
Reverted (due to buildbot failure - breaking lldb) in 7a45aeacf3.
I still can't seem to build lldb locally, but Pavel Labath has kindly
provided a potential fix to preserve the old behavior in lldb by
registering a simple recoverable error handler there that prints to the
desired stream in lldb, rather than stderr.
Types that came from a Clang module are nested in DW_TAG_module tags
in DWARF. This patch recreates the Clang module hierarchy in LLDB and
1;95;0csets the owning module information accordingly. My primary motivation
is to facilitate looking up per-module APINotes for individual
declarations, but this likely also has other applications.
This reapplies the previously reverted commit, but without support for
ClassTemplateSpecializations, which I'm going to look into separately.
rdar://problem/59634380
Differential Revision: https://reviews.llvm.org/D75488
Types that came from a Clang module are nested in DW_TAG_module tags
in DWARF. This patch recreates the Clang module hierarchy in LLDB and
sets the owning module information accordingly. My primary motivation
is to facilitate looking up per-module APINotes for individual
declarations, but this likely also has other applications.
rdar://problem/59634380
Differential Revision: https://reviews.llvm.org/D75488
D63643 added these testfiles but some of the %t4dwo and %t5dwo builds
are the same as corresponding %t4 and %t5 builds. Fortunately the
testcases do PASS.
After just adding -gsplit-dwarf these both skeleton files:
tools/lldb/test/SymbolFile/DWARF/Output/debug-types-expressions.test.tmp4dwo
tools/lldb/test/SymbolFile/DWARF/Output/debug-types-expressions.test.tmp5dwo
were referencing to this one non-skeleton file:
tools/lldb/test/SymbolFile/DWARF/debug-types-expressions.dwo
Surprisingly it does not affect the other test debug-types-basic.test
probably because it compiles to .o and then links it. While
debug-types-expressions.test compiles directly to an executable.
So fixed that while keeping the direct executable compilation.
Differential Revision: https://reviews.llvm.org/D76316
These can come out nondeterministically for two reasons:
- sorting based on ConstStringified pointer values
- different relative speeds of the indexing threads
Making these nondeterministic without incurring performance penalties is
hard, so I just make the test expect them in any order (the order is not
important in this test anyway.
The convention is that the dwp file name is derived from the name of the
file holding the executable code, even if the linked portion of the
debug info is elsewhere (objcopy --only-keep-debug).
Summary:
When we added support for type units in dwo files, we changed the
"manual" dwarf index to index _all_ dwarf units in the dwo file instead
of just the split unit belonging to our skeleton unit. This was fine for
dwo files, as they contain only a single compile units and type units do
not have a split type unit which would point to them.
However, this does not work for dwp files because, these files do
contain multiple split compile units, and the current approach means
that each unit gets indexed multiple times (once for each split unit =>
n^2 complexity).
This patch teaches the manual dwarf index to treat dwp files specially.
Any type units in the dwp file added to the main list of compile units
and indexed with them in a single batch. Split compile units in dwp
files are still indexed as a part of their skeleton unit -- this is done
because we need the DW_AT_language attribute from the skeleton unit to
index them properly.
Handling of dwo files remains unchanged -- all units (type and skeleton)
are indexed when we reach the dwo file through the split unit.
Reviewers: clayborg, JDevlieghere, aprantl
Subscribers: arphaman, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D74964
The only thing needed was to account for the offset from the
debug_cu_index section when searching for the location list.
This patch also fixes a bug in the Module::ParseAllDebugSymbols
function, which meant that we would only parse the variables of the
first compile unit in the module. This function is only used from
lldb-test, so this does not fix any real issue, besides preventing me
from writing a test for this patch.
Summary:
In dwp files a constant (from the debug_cu_index section) needs to be
added to each reference into the debug_str_offsets section.
I've tried to implement this to roughly match the llvm flow: I've
changed the DWARFormValue to stop resolving the indirect string
references directly -- instead, it calls into DWARFUnit, which resolves
this for it (similar to how it already resolves indirect range and
location list references). I've also done a small refactor of the string
offset base computation code in DWARFUnit in order to make it easier to
access the debug_cu_index base offset.
Reviewers: JDevlieghere, aprantl, clayborg
Subscribers: lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D74723
Summary:
This patch removes the bitrotted SymbolFileDWARF(Dwo)Dwp classes, and
replaces them with dwp support implemented directly inside
SymbolFileDWARFDwo, in a manner mirroring the implementation in llvm.
This patch does:
- add support for the .debug_cu_index section to our DWARFContext
- adds a llvm::DWARFUnitIndex argument to the DWARFUnit constructors.
This argument is used to look up the offsets of the debug_info and
debug_abbrev contributions in the sections of the dwp file.
- makes sure the creation of the DebugInfo object as well as the initial
discovery of DWARFUnits is thread-safe, as we can now call this
concurrently when doing parallel indexing.
This patch does not:
- use the DWARFUnitIndex to search for other kinds of contributions
(debug_loc, debug_ranges, etc.). This means that units which reference
these sections will not work correctly. These will be handled by
follow-up patches, but even the present level of support is sufficient
to enable basic functionality.
- Make the llvm::DWARFContext thread-safe. Right now, it just avoids this
problem by ensuring everything is initialized ahead of time. However,
this is something we will run into more often as we try to use more of
llvm, and so I plan to start looking into our options here.
Reviewers: JDevlieghere, aprantl, clayborg
Subscribers: mgorny, mgrang, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D73783
Value::GetValueByteSize() reports the size of a Value as the size of its
underlying CompilerType. However, a host buffer that backs a Value may
be smaller than GetValueByteSize().
This situation arises when the host is only able to partially evaluate a
Value, e.g. because the expression contains DW_OP_piece.
The cleanest fix I've found to this problem is Greg's suggestion, which
is to resize the Value if (after evaluating an expression) it's found to
be too small. I've tried several alternatives which all (in one way or
the other) tried to teach the Value/ValueObjectChild system not to read
past the end of a host buffer, but this was flaky and impractical as it
isn't easy to figure out the host buffer's size (Value::GetScalar() can
point to somewhere /inside/ a host buffer, but you need to walk up the
ValueObject hierarchy to try and find its size).
This fixes an ASan error in lldb seen when debugging a clang binary.
I've added a regression test in test/functionalities/optimized_code. The
point of that test is not specifically to check that DW_OP_piece is
handled a particular way, but rather to check that lldb doesn't crash on
an input that it used to crash on.
Testing: check-lldb, and running the added tests using a sanitized lldb
--
Thanks to Jim for pointing out that an earlier version of this patch,
which simply changed the definition of Value::GetValueByteSize(), would
interact poorly with the ValueObject machinery.
Thanks also to Pavel who suggested a neat way to test this change
(which, incidentally, caught another ASan issue still present in the
original version of this patch).
rdar://58665925
Differential Revision: https://reviews.llvm.org/D73148
The CMakeLists.txt had a typo which meant that check-lldb-repro was
capturing twice instead of capturing and then replaying. This also
uncovered a missing import in lldb-repro.py. This patch fixes both
issues.
This reverts commit 1b12766883 because of
breaking the mac test suite.
I'm not certain this is the cause because of a concurrent build breakage
which masked this problem, but the failure messages are related to
symbol lookup, which makes this very likely.
Summary:
In the spirit of https://reviews.llvm.org/D70846, we only return functions with matching mangled name from Apple/DebugNamesDWARFIndex::GetFunction if eFunctionNameTypeFull is requested.
This speeds up lookup in the presence of large amount of class methods of the same name (a typical examples would be constructors of templates with many instantiations or overloaded operators).
Reviewers: labath
Reviewed By: labath
Subscribers: aprantl, arphaman, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D73191
As explained in Pavel's previous commit message: %lldb is the proper
substitution. Using "lldb" can cause us to execute the system lldb
instead of the one we are testing. This happens at least in standalone
builds.
Summary:
The goal of this patch is two-fold. First, it fixes a use-after-free in
the construction of the llvm DWARFContext. This happened because the
construction code was throwing away the lldb DataExtractors it got while
reading the sections (unlike their llvm counterparts, these are also
responsible for memory ownership). In most cases this did not matter,
because the sections are just slices of the mmapped file data. But this
isn't the case for compressed elf sections, in which case the section is
decompressed into a heap buffer. A similar thing also happen with object
files which are loaded from process memory.
The second goal is to make it explicit which sections go into the llvm
DWARFContext -- any access to the sections through both DWARF parsers
carries a risk of parsing things twice, so it's better if this is a
conscious decision. Also, this avoids loading completely irrelevant
sections (e.g. .text). At present, the only section that needs to be
present in the llvm DWARFContext is the debug_line_str. Using it through
both APIs is not a problem, as there is no parsing involved.
The first goal is achieved by loading the sections through the existing
lldb DWARFContext APIs, which already do the caching. The second by
explicitly enumerating the sections we wish to load.
Reviewers: JDevlieghere, aprantl
Subscribers: lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D72917
