The way the IO handlers are currently managed by the debugger is wrong. The
implementation lacks proper synchronization between RunIOHandlerSync and
RunIOHandlers. The latter is meant to be run by the "main thread", while the
former is meant to be run synchronously, potentially from a different thread.
Imagine a scenario where RunIOHandlerSync is called from a different thread
than RunIOHandlers. Both functions manipulate the debugger's IOHandlerStack.
Although the push and pop operations are synchronized, the logic to activate,
deactivate and run IO handlers is not.
While investigating PR44352, I noticed some weird behavior in the Editline
implementation. One of its members (m_editor_status) was modified from another
thread. This happened because the main thread, while running RunIOHandlers
ended up execution the IOHandlerEditline created by the breakpoint callback
thread. Even worse, due to the lack of synchronization within the IO handler
implementation, both threads ended up executing the same IO handler.
Most of the time, the IO handlers don't need to run synchronously. The
exception is sourcing commands from external files, like the .lldbinit file.
I've added a (recursive) mutex to prevent another thread from messing with the
IO handlers wile another thread is running one synchronously. It has to be
recursive, because we might have to source another file when encountering a
command source in the original file.
Differential revision: https://reviews.llvm.org/D72748
Summary:
CXXRecordDecls that have a move constructor but no copy constructor need to
have their implicit copy constructor marked as deleted (see C++11 [class.copy]p7, p18)
Currently we don't do that when building an AST with ClangASTContext which causes
Sema to realise that the AST is malformed and asserting when trying to create an implicit
copy constructor for us in the expression:
```
Assertion failed: ((data().DefaultedCopyConstructorIsDeleted || needsOverloadResolutionForCopyConstructor())
&& "Copy constructor should not be deleted"), function setImplicitCopyConstructorIsDeleted, file include/clang/AST/DeclCXX.h, line 828.
```
In the test case there is a class `NoCopyCstr` that should have its copy constructor marked as
deleted (as it has a move constructor). When we end up trying to tab complete in the
`IndirectlyDeletedCopyCstr` constructor, Sema realises that the `IndirectlyDeletedCopyCstr`
has no implicit copy constructor and tries to create one for us. It then realises that
`NoCopyCstr` also has no copy constructor it could find via lookup. However because we
haven't marked the FieldDecl as having a deleted copy constructor the
`needsOverloadResolutionForCopyConstructor()` returns false and the assert fails.
`needsOverloadResolutionForCopyConstructor()` would return true if during the time we
added the `NoCopyCstr` FieldDecl to `IndirectlyDeletedCopyCstr` we would have actually marked
it as having a deleted copy constructor (which would then mark the copy constructor of
`IndirectlyDeletedCopyCstr ` as needing overload resolution and Sema is happy).
This patch sets the correct mark when we complete our CXXRecordDecls (which is the time when
we know whether a copy constructor has been declared). In theory we don't have to do this if
we had a Sema around when building our debug info AST but at the moment we don't have this
so this has to do the job for now.
Reviewers: shafik
Reviewed By: shafik
Subscribers: aprantl, JDevlieghere, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D72694
Summary:
Normally, on linux we retrieve the process ID from the LinuxProcStatus
stream (which is just the contents of /proc/%d/status pseudo-file).
However, this stream is not strictly required (it's a breakpad
extension), and we are encountering a fair amount of minidumps which do
not have it present. It's not clear whether this is the case with all
these minidumps, but the two known situations where this stream can be
missing are:
- /proc filesystem not mounted (or something to that effect)
- process crashing after exhausting (almost) all file descriptors (so
the minidump writer may not be able to open the /proc file)
Since this is a corner case which will become less and less relevant
(crashpad-generated minidumps should not suffer from this problem), I
work around this problem by hardcoding the PID to 1 in these cases.
The same thing is done by the gdb plugin when talking to a stub which
does not report a process id (e.g. a hardware probe).
Reviewers: jingham, clayborg
Subscribers: markmentovai, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D70238
Summary:
This code is handling debug info paths starting with /proc/self/cwd,
which is one of the mechanisms people use to obtain "relocatable" debug
info (the idea being that one starts the debugger with an appropriate
cwd and things "just work").
Instead of resolving the symlinks inside DWARFUnit, we can do the same
thing more elegantly by hooking into the existing Module path remapping
code. Since llvm::DWARFUnit does not support any similar functionality,
doing things this way is also a step towards unifying llvm and lldb
dwarf parsers.
Reviewers: JDevlieghere, aprantl, clayborg, jdoerfert
Subscribers: lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D71770
Summary:
Motivation: When setting breakpoints in certain projects line sequences are frequently being inserted out of order.
Rather than inserting sequences one at a time into a sorted line table, store all the line sequences as we're building them up and sort and flatten afterwards.
Reviewers: jdoerfert, labath
Reviewed By: labath
Subscribers: teemperor, labath, mgrang, JDevlieghere, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D72909
Summary:
This method was doing a lot more than it's only caller needed
(DWARFDIE::LookupDeepestBlock) needed, so I inline it into the caller,
and remove any code which is not actually used. This includes code for
searching for the deepest function, and the code for working around
incomplete DW_AT_low_pc/high_pc attributes on a compile unit DIE (modern
compiler get this right, and this method is called on function DIEs
anyway).
This also improves our llvm consistency, as llvm::DWARFDebugInfoEntry is
just a very simple struct with no nontrivial logic.
Reviewers: JDevlieghere, aprantl
Subscribers: lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D72920
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
[this re-applies c0176916a4
with the correct commit message and phabricator link]
This addresses point 1 of PR44213.
https://bugs.llvm.org/show_bug.cgi?id=44213
The DW_AT_LLVM_sysroot attribute is used for Clang module debug info,
to allow LLDB to import a Clang module from source. Currently it is
part of each DW_TAG_module, however, it is the same for all modules in
a compile unit. It is more efficient and less ambiguous to store it
once in the DW_TAG_compile_unit.
This should have no effect on DWARF consumers other than LLDB.
Differential Revision: https://reviews.llvm.org/D71732
This is a purely cosmetic change that is NFC in terms of the binary
output. I bugs me that I called the attribute DW_AT_LLVM_isysroot
since the "i" is an artifact of GCC command line option syntax
(-isysroot is in the category of -i options) and doesn't carry any
useful information otherwise.
This attribute only appears in Clang module debug info.
Differential Revision: https://reviews.llvm.org/D71722
and document the shortcomings of LLDB's partially defined DW_OP_piece
handling.
This would manifest as "DW_OP_piece for offset foo but top of stack is
of size bar".
rdar://problem/46262998
Differential Revision: https://reviews.llvm.org/D72880
By switching to Scalars that are backed by explicitly-sized APInts we
can avoid a bug that increases the buffer reserved for a small piece
to the next-largest host integer type.
This manifests as "DW_OP_piece for offset foo but top of stack is of size bar".
Differential Revision: https://reviews.llvm.org/D72879
When LLVM_APPEND_VC_REV=OFF is set, the current git hash is no
longer embedded into binaries (mostly for --version output).
Without it, most binaries need to relink after every single
commit, even if they didn't change otherwise (due to, say,
a documentation-only commit).
LLVM_APPEND_VC_REV is ON by default, so this doesn't change the
default behavior of anything.
With this, all clients of GenerateVersionFromVCS.cmake honor
LLVM_APPEND_VC_REV.
Differential Revision: https://reviews.llvm.org/D72855
Add a flag which always generates a reproducer when normally it would be
discarded. This is meant for testing purposes to capture a debugger
session without modification the session itself.
size_t and uint64_t are spelled slightly differently on macOS, which was
causing the compiler to error out calling std::min - since the two types have
to be the same.
I fixed this by casting the uint64_t computation to a size_t. That's probably
not the cleanest solution, but it gets us back to building.
Summary:
This is the first in a series of patches to enable LLDB debugging of
WebAssembly targets.
Current versions of Clang emit (partial) DWARF debug information in WebAssembly
modules and we can leverage this debug information to give LLDB the ability to
do source-level debugging of Wasm code that runs in a WebAssembly engine.
A way to do this could be to use the remote debugging functionalities provided
by LLDB via the GDB-remote protocol. Remote debugging can indeed be useful not
only to connect a debugger to a process running on a remote machine, but also to
connect the debugger to a managed VM or script engine that runs locally,
provided that the engine implements a GDB-remote stub that offers the ability to
access the engine runtime internal state.
To make this work, the GDB-remote protocol would need to be extended with a few
Wasm-specific custom query commands, used to access aspects of the Wasm engine
state (like the Wasm memory, Wasm local and global variables, and so on).
Furthermore, the DWARF format would need to be enriched with a few Wasm-specific
extensions, here detailed: https://yurydelendik.github.io/webassembly-dwarf.
This CL introduce classes **ObjectFileWasm**, a file plugin to represent a Wasm
module loaded in a debuggee process. It knows how to parse Wasm modules and
store the Code section and the DWARF-specific sections.
Reviewers: jasonmolenda, clayborg, labath
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D71575
This reverts D53469, which changed llvm's DWARF emission to emit
DW_AT_call_return_pc as a function-local offset. Such an encoding is not
compatible with post-link block re-ordering tools and isn't standards-
compliant.
In addition to reverting back to the original DW_AT_call_return_pc
encoding, teach lldb how to fix up DW_AT_call_return_pc when the address
comes from an object file pointed-to by a debug map. While doing this I
noticed that lldb's support for tail calls that cross a DSO/object file
boundary wasn't covered, so I added tests for that. This latter case
exercises the newly added return PC fixup.
The dsymutil changes in this patch were originally included in D49887:
the associated test should be sufficient to test DW_AT_call_return_pc
encoding purely on the llvm side.
Differential Revision: https://reviews.llvm.org/D72489
The 'asynchronously' argument to both GetLLDBCommandsFromIOHandler and
GetPythonCommandsFromIOHandler is true for all call sites. This commit
simplifies the API by dropping it and giving the baton a default
argument.
llvm_unreachable is marked noreturn so the compiler can assume the code
for printing the error message in release builds isn't hit which defeats
the purpose.
These are the last sections not managed by the DWARFContext object. I
also introduce separate SectionType enums for dwo section variants, as
this is necessary for proper handling of single-file split dwarf.
Summary:
This change is connected with
https://reviews.llvm.org/D69843
In large codebases, we sometimes see Module::FindFunctions (when called from
ClangExpressionDeclMap::FindExternalVisibleDecls) returning huge amounts of
functions.
In current fix I trying to return only function_fullnames from ManualDWARFIndex::GetFunctions when eFunctionNameTypeFull is passed as argument.
Reviewers: labath, jarin, aprantl
Reviewed By: labath
Subscribers: shafik, clayborg, teemperor, arphaman, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D70846
When trying to interpret an expression with a function call, if the
process hasn't been launched, the expression fails to be interpreted
and the user gets the following error message:
```error: Can't run the expression locally```
This message doesn't explain why the expression failed to be
interpreted, that's why this patch improves the error message that is
displayed when trying to run an expression while no process is running.
rdar://11991708
Differential Revision: https://reviews.llvm.org/D72510
Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>
Makes this function exit early instead of nesting if statements.
Also removed all the if (tag_type->getDecl()) checks. If we created
a TagType with a nullptr as a Decl then Clang would have already
deferenced that nullptr during TagType creation so there is no point
in gracefully handling a nullptr here.
Summary:
Whenever we cast an LLVM instruction to one of its subclasses, we do a double check if the RTTI
enum value actually allows us to cast the class. I don't see a way this can ever happen as even when
LLVM's RTTI system has some corrupt internal state (which we probably should not test in the first
place) we just reuse LLVM RTTI to do the second check.
This also means that if we ever make an actual programming error in this function (e.g., have a enum
value and then cast it to a different subclass), we just silently fall back to the JIT in our tests.
We also can't test this code in any reasonable way.
This removes the checks and uses `llvm::cast` instead which will raise a fatal error when casting fails.
Reviewers: labath, mib
Reviewed By: labath
Subscribers: abidh, JDevlieghere, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D72596
This fixes a failing testcase on Fedora 30 x86_64 (regression Fedora 29->30):
PASS:
./bin/lldb ./lldb-test-build.noindex/functionalities/unwind/noreturn/TestNoreturnUnwind.test_dwarf/a.out -o 'settings set symbols.enable-external-lookup false' -o r -o bt -o quit
* frame #0: 0x00007ffff7aa6e75 libc.so.6`__GI_raise + 325
frame #1: 0x00007ffff7a91895 libc.so.6`__GI_abort + 295
frame #2: 0x0000000000401140 a.out`func_c at main.c:12:2
frame #3: 0x000000000040113a a.out`func_b at main.c:18:2
frame #4: 0x0000000000401134 a.out`func_a at main.c:26:2
frame #5: 0x000000000040112e a.out`main(argc=<unavailable>, argv=<unavailable>) at main.c:32:2
frame #6: 0x00007ffff7a92f33 libc.so.6`__libc_start_main + 243
frame #7: 0x000000000040106e a.out`_start + 46
vs.
FAIL - unrecognized abort() function:
./bin/lldb ./lldb-test-build.noindex/functionalities/unwind/noreturn/TestNoreturnUnwind.test_dwarf/a.out -o 'settings set symbols.enable-external-lookup false' -o r -o bt -o quit
* frame #0: 0x00007ffff7aa6e75 libc.so.6`.annobin_raise.c + 325
frame #1: 0x00007ffff7a91895 libc.so.6`.annobin_loadmsgcat.c_end.unlikely + 295
frame #2: 0x0000000000401140 a.out`func_c at main.c:12:2
frame #3: 0x000000000040113a a.out`func_b at main.c:18:2
frame #4: 0x0000000000401134 a.out`func_a at main.c:26:2
frame #5: 0x000000000040112e a.out`main(argc=<unavailable>, argv=<unavailable>) at main.c:32:2
frame #6: 0x00007ffff7a92f33 libc.so.6`.annobin_libc_start.c + 243
frame #7: 0x000000000040106e a.out`.annobin_init.c.hot + 46
The extra ELF symbols are there due to Annobin (I did not investigate why this
problem happened specifically since F-30 and not since F-28).
It is due to:
Symbol table '.dynsym' contains 2361 entries:
Valu e Size Type Bind Vis Name
0000000000022769 5 FUNC LOCAL DEFAULT _nl_load_domain.cold
000000000002276e 0 NOTYPE LOCAL HIDDEN .annobin_abort.c.unlikely
...
000000000002276e 0 NOTYPE LOCAL HIDDEN .annobin_loadmsgcat.c_end.unlikely
...
000000000002276e 0 NOTYPE LOCAL HIDDEN .annobin_textdomain.c_end.unlikely
000000000002276e 548 FUNC GLOBAL DEFAULT abort
000000000002276e 548 FUNC GLOBAL DEFAULT abort@@GLIBC_2.2.5
000000000002276e 548 FUNC LOCAL DEFAULT __GI_abort
0000000000022992 0 NOTYPE LOCAL HIDDEN .annobin_abort.c_end.unlikely
GDB has some more complicated preferences between overlapping and/or sharing
address symbols, I have made here so far the most simple fix for this case.
Differential revision: https://reviews.llvm.org/D63540
The argument is llvm::null() everywhere except llvm::errs() in
llvm-objdump in -DLLVM_ENABLE_ASSERTIONS=On builds. It is used by no
target but X86 in -DLLVM_ENABLE_ASSERTIONS=On builds.
If we ever have the needs to add verbose log to disassemblers, we can
record log with a member function, instead of passing it around as an
argument.
I modified the SBAPI under the assumption that nobody was using the old
API yet. However, that turns out to be false. So instead of adding the
deafault argument I've reintroduced the old API and made the new one an
overload.
Summary:
We iterate over `m_decls_to_complete` to complete declarations. As
`m_decls_to_complete` is a set the iteration order can be non-deterministic.
The order is currently only non-deterministic when we have
a large set of decls that need to be completed (i.e. more than 32 decls,
as otherwise the SmallPtrSet is just a linear-searched list).
This doesn't really fix any specific bug or has any really observable
change in behavior as the order in which we import should not influence
any semantics. However the order we create decls/types is now always
deterministic which should make debugging easier.
Reviewers: labath, mib, shafik, davide
Reviewed By: shafik, davide
Subscribers: davide, abidh, JDevlieghere, lldb-commits, mgrang
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D72495
Summary:
This is a port of D67803 that was about preventing indirect importing to our scratch context when evaluating expressions.
D67803 already has a pretty long explanation of how this works, but the idea is that instead
of importing declarations indirectly over the expression AST (i.e., Debug info AST -> Expression AST -> scratch AST)
we instead directly import the declaration from the debug info AST to the scratch AST.
The difference from D67803 is that here we have to do this in the ASTImporterDelegate (which is our ASTImporter
subclass we use in LLDB). It has the same information as the ExternalASTMerger in D67803 as it can access the
ClangASTImporter (which also keeps track of where Decls originally came from).
With this patch we can also delete the FieldDecl stealing hack in the ClangASTSource (this was only necessary as the
indirect imports caused the creation of duplicate Record declarations but we needed the fields in the Record decl
we originally found in the scratch ASTContext).
This also fixes the current gmodules failures where we fail to find std::vector fields after an indirect import
over the expression AST (where it seems even our FieldDecl stealing hack can't save us from).
Reviewers: shafik, aprantl
Reviewed By: shafik
Subscribers: JDevlieghere, lldb-commits, mib, labath, friss
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D72507
GetPersistentExpressionStateForLanguage() can return a nullptr if it
cannot construct a typesystem. This patch adds missing nullptr checks
at all uses.
Inspired by rdar://problem/58317195
Differential Revision: https://reviews.llvm.org/D72413
This patch removes the code (deep inside DWARFDebugInfoEntry) which
automagically returned the attributes of the dwo unit DIE when asking
for the attributes of the skeleton unit. This is fairly hacky, and not
consistent with how llvm DWARF parser operates.
Instead, I change the code the explicitly request (via
GetNonSkeletonUnit) the right unit to search (there were just two places
that needed this). If it turns out we need this more often, we can
create a utility function (external to DWARFUnit) for doing this.
Summary:
Motivation: When formatting an array of typedefed chars, we would like to display the array as a string.
The string formatter currently does not trigger because the formatter lookup does not resolve typedefs for array elements (this behavior is inconsistent with pointers, for those we do look through pointee typedefs). This patch tries to make the array formatter lookup somewhat consistent with the pointer formatter lookup.
Reviewers: teemperor, clayborg
Reviewed By: teemperor, clayborg
Subscribers: clayborg, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D72133
qemu has a very small maximum packet size (4096) and it actually
only uses half of that buffer for some implementation reason,
so when lldb asks for the register target definitions, the x86_64
definition is larger than 4096/2 and we need to fetch it in two parts.
This patch and test is fixing a bug in
GDBRemoteCommunicationClient::ReadExtFeature when reading a target
file in multiple parts. lldb was assuming that it would always
get back the maximum packet size response (4096) instead of
using the actual size received and asking for the next group of
bytes.
We now have two tests in gdb_remote_client for unique features
of qemu - TestNestedRegDefinitions.py would test the ability
of lldb to follow multiple levels of xml includes; I opted to
create a separate TestRegDefinitionInParts.py test to test this
wrinkle in qemu's gdb remote serial protocol stub implementation.
Instead of combining both tests into a single test file.
<rdar://problem/49537922>
All the code required to generate the language bindings for Python and
Lua lives under scripts, even though the majority of this code aren't
scripts at all, and surrounded by scripts that are totally unrelated.
I've reorganized these files and moved everything related to the
language bindings into a new top-level directory named bindings. This
makes the corresponding files self contained and much more discoverable.
Differential revision: https://reviews.llvm.org/D72437
Jonas Devlieghere