Summary:
This patch simplifies register accesses in NativeRegisterContextLinux_arm64
and also adds some bare minimum caching to avoid multiple calls to ptrace
during a stop.
Linux ptrace returns data in the form of structures containing GPR/FPR data.
This means that one single call is enough to read all GPRs or FPRs. We do
that once per stop and keep reading from or writing to the buffer that we
have in NativeRegisterContextLinux_arm64 class. Before a resume or detach we
write all buffers back.
This is tested on aarch64 thunder x1 with Ubuntu 18.04. Also tested
regressions on x86_64.
Reviewers: labath, clayborg
Reviewed By: labath
Subscribers: kristof.beyls, lldb-commits
Differential Revision: https://reviews.llvm.org/D69371
In DWARF5 DW_AT_low_pc (and DW_AT_entry_pc, and possibly others) can use
DW_FORM_addrx to refer to the address indirectly. This means we need to
have processed the DW_AT_addr_base attribute before we can do anything
with these.
Since we were processing the unit attributes serially, this created a
problem in cases where the DW_AT_addr_base comes after DW_AT_low_pc --
we would end up computing the wrong unit base address, which also
corrupted any values which later depended on that (for instance range
lists). Clang currently always emits DW_AT_addr_base last.
The fix is simple -- process DW_AT_addr_base first, regardless of its
position in the attribute list.
the value of DW_AT_rnglists_base of the skeleton unit is for that unit
alone (e.g. used in DW_AT_ranges of the unit DIE) and should not apply
to the split unit.
The split unit has a hardcoded range list base value -- we should
initialize range list code whenever we detect a nonempty
debug_rnglists.dwo section.
Summary:
Yet another step on the long road towards getting rid of lldb's Stream class.
We probably should just make this some kind of member of Address/AddressRange, but it seems quite often we just push
in random integers in there and this is just about getting rid of Stream and not improving arbitrary APIs.
I had to rename another `DumpAddress` function in FormatEntity that is dumping the content of an address to make Clang happy.
Reviewers: labath
Reviewed By: labath
Subscribers: JDevlieghere, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D71052
Summary:
Our rnglist support was working only for the trivial cases (one CU),
because we only ever parsed one contribution out of the debug_rnglists
section. This means we were never able to resolve range lists for the
second and subsequent units (DW_FORM_sec_offset references came out
blang, and DW_FORM_rnglistx references always used the ranges lists from
the first unit).
Since both llvm and lldb rnglist parsers are sufficiently
self-contained, and operate similarly, we can fix this problem by
switching to the llvm parser instead. Besides the changes which are due
to variations in the interface, the main thing is that now the range
list object is a member of the DWARFUnit, instead of the entire symbol
file. This ensures that each unit can get it's own private set of range
list indices, and is consistent with how llvm's DWARFUnit does it
(overall, I've tried to structure the code the same way as the llvm
version).
I've also added a test case for the two unit scenario.
Reviewers: JDevlieghere, aprantl, clayborg
Subscribers: dblaikie, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D71021
Summary:
This patch adds code which will substitute references to the full object
constructors/destructors with their base object versions.
Like all substitutions in this category, this operation is not really
sound, but doing this in a more precise way allows us to get rid of a
much larger hack -- matching function according to their demangled
names, which effectively does the same thing, but also much more.
This is a (very late) follow-up to D54074.
Background: clang has an optimization which can eliminate full object
structors completely, if they are found to be equivalent to their base
object versions. It does this because it assumes they can be regenerated
on demand in the compile unit that needs them (e.g., because they are
declared inline). However, this doesn't work for the debugging scenario,
where we don't have the structor bodies available -- we pretend all
constructors are defined out-of-line as far as clang is concerned. This
causes clang to emit references to the (nonexisting) full object
structors during expression evaluation.
Fun fact: This is not a problem on darwin, because the relevant
optimization is disabled to work around a linker bug.
Reviewers: teemperor, JDevlieghere
Subscribers: lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D70721
Summary:
Lldb's "format-independent" debug info made use of the fact that DWARF
(<=4) did not use the file index zero, and reused the support file index
zero for storing the compile unit name.
While this provided some convenience for DWARF<=4, it meant that the PDB
plugin needed to artificially remap file indices in order to free up
index 0. Furthermore, DWARF v5 make file index 0 legal, which meant that
similar remapping would be needed in the dwarf plugin too.
What this patch does instead is remove the requirement of having the
compile unit name in the index 0. It is not that useful since the name
can always be fetched from the CompileUnit object. Remapping code in the
pdb plugin(s) has been removed or simplified.
DWARF plugin has started inserting an empty FileSpec at index 0 to
ensure the indices keep matching up (in case of DWARF<=4). For DWARF5,
we insert the file 0 from the line table.
I add a test to ensure we can correctly lookup line table entries
referencing file 0, and in particular the case where the file 0 is also
duplicated in another file entry, as this is how clang produces line
tables in some circumstances (see pr44170). Though this is probably a
bug in clang, this is not forbidden by DWARF, and lldb already has
support for that in some (but not all) cases -- this adds a test for the
code path which was not fixed in this patch.
Reviewers: clayborg, JDevlieghere, jdoerfert
Subscribers: aprantl, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D70954
Summary:
The FileSpec class is often used as a sort of a pattern -- one specifies
a bare file name to search, and we check if in matches the full file
name of an existing module (for example).
These comparisons used FileSpec::Equal, which had some support for it
(via the full=false argument), but it was not a good fit for this job.
For one, it did a symmetric comparison, which makes sense for a function
called "equal", but not for typical searches (when searching for
"/foo/bar.so", we don't want to find a module whose name is just
"bar.so"). This resulted in patterns like:
if (FileSpec::Equal(pattern, file, pattern.GetDirectory()))
which would request a "full" match only if the pattern really contained
a directory. This worked, but the intended behavior was very unobvious.
On top of that, a lot of the code wanted to handle the case of an
"empty" pattern, and treat it as matching everything. This resulted in
conditions like:
if (pattern && !FileSpec::Equal(pattern, file, pattern.GetDirectory())
which are nearly impossible to decipher.
This patch introduces a FileSpec::Match function, which does exactly
what most of FileSpec::Equal callers want, an asymmetric match between a
"pattern" FileSpec and a an actual FileSpec. Empty paterns match
everything, filename-only patterns match only the filename component.
I've tried to update all callers of FileSpec::Equal to use a simpler
interface. Those that hardcoded full=true have been changed to use
operator==. Those passing full=pattern.GetDirectory() have been changed
to use FileSpec::Match.
There was also a handful of places which hardcoded full=false. I've
changed these to use FileSpec::Match too. This is a slight change in
semantics, but it does not look like that was ever intended, and it was
more likely a result of a misunderstanding of the "proper" way to use
FileSpec::Equal.
[In an ideal world a "FileSpec" and a "FileSpec pattern" would be two
different types, but given how widespread FileSpec is, it is unlikely
we'll get there in one go. This at least provides a good starting point
by centralizing all matching behavior.]
Reviewers: teemperor, JDevlieghere, jdoerfert
Subscribers: emaste, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D70851
ParseChildMembers does a few things, only one part is actually parsing a single
member. This extracts the member parsing logic into its own function.
This commit just moves the code as-is into its own function and forwards the parameters/
local variables to it, which means it should be NFC.
The only actual changes to the code are replacing 'break's (and one very curious 'continue'
that behaves like a 'break') with 'return's.
This code was just creating a new SymbolContextList with any found functions
in the front and orders them by how close they are to the current frame.
This refactors this code into its own function to make this more obvious.
Doesn't do any other changes to the code, so this is NFC.
Summary:
Previously the ABI plugin exposed some "register infos" and the
gdb-remote code used those to fill in the missing bits. Now, the
"filling in" code is in the ABI plugin itself, and the gdb-remote code
just invokes that.
The motivation for this is two-fold:
a) the "augmentation" logic is useful outside of process gdb-remote. For
instance, it would allow us to avoid repeating the register number
definitions in minidump code.
b) It gives more implementation freedom to the ABI classes. Now that
these "register infos" are essentially implementation details, classes
can use other methods to obtain dwarf/eh_frame register numbers -- for
instance they can consult llvm MC layer.
Since the augmentation code was not currently tested anywhere, I took
the opportunity to create a simple test for it.
Reviewers: jasonmolenda, clayborg, tatyana-krasnukha
Subscribers: aprantl, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D70906
Extend EmulateMOVRdRm to identify "mov r11, sp" in thumb mode as
setting the frame pointer, if r11 is the frame pointer register.
Differential Revision: https://reviews.llvm.org/D70797
ClangASTSource currently takes a clang::ASTContext and keeps that
around, but a lot of LLDB's functionality for doing operations
on a clang::ASTContext is in its ClangASTContext twin class. We
currently constantly recompute the respective ClangASTContext
from the clang::ASTContext while we instead could just pass and
store a ClangASTContext in the ClangASTSource. This also allows
us to get rid of a bunch of unreachable error checking for cases
where recomputation fails for some reason.
This code is behind a `if (log)` that is always a nullptr as the initializer
was commented out. One could uncomment the initializer code, but then this logging
code just leads to a deadlock as it tries to aquire the module lock.
This removes the logging code until I get this working again.
Summary:
CompileUnit is a complicated class. Having it be implicitly convertible
to a FileSpec makes reasoning about it even harder.
This patch replaces the inheritance by a simple member and an accessor
function. This avoid the need for casting in places where one needed to
force a CompileUnit to be treated as a FileSpec, and does not add much
verbosity elsewhere.
It also fixes a bug where we were wrongly comparing CompileUnit& and a
CompileUnit*, which compiled due to a combination of this inheritance
and the FileSpec*->FileSpec implicit constructor.
Reviewers: teemperor, JDevlieghere, jdoerfert
Subscribers: lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D70827
COFF section names can either be stored truncated to 8 chars, in the
section header, or as a longer section name, stored separately in the
string table.
libunwind locates the .eh_frame section by runtime introspection,
which only works for section names stored in the section header (as
the string table isn't mapped at runtime). To support this behaviour,
lld always truncates the section names for sections that will be
mapped, like .eh_frame.
Differential Revision: https://reviews.llvm.org/D70745
InitializeContext is useful for allocating a (potentially variable
size) CONTEXT struct in an unaligned byte buffer. In this case, we
already have a fixed size CONTEXT we want to initialize, and we only
used this as a very roundabout way of zero initializing it.
Instead just memset the CONTEXT we have, and set the ContextFlags field
manually.
This matches how it is done in NativeRegisterContextWindows_*.cpp.
This also makes LLDB run successfully in Wine (for a trivial tested
case at least), as Wine hasn't implemented the InitializeContext
function.
Differential Revision: https://reviews.llvm.org/D70742
This way it looks more like the code around it. The assert is also gone as it just
checks that the variables we declare directly above were not initialized by anyone.
That made more sense when this was one large function.
Part of the work to split up this monolithic parsing function.
Should be NFC but due to the kafkaesque control flow in this case statement this might
have some unintended side effects.
Fix handling concurrent watchpoint events so that they are reported
correctly in LLDB.
If multiple watchpoints are hit concurrently, the NetBSD kernel reports
them as series of SIGTRAPs with a thread specified, and the debugger
investigates DR6 in order to establish which watchpoint was hit. This
is normally fine.
However, LLDB disables and reenables the watchpoint on all threads after
each hit, which results in the hit status from DR6 being wiped.
As a result, it can't establish which watchpoint was hit in successive
SIGTRAP processing.
In order to workaround this problem, clear DR6 only if the breakpoint
is overwritten with a new one. More specifically, move cleaning DR6
from ClearHardwareWatchpoint() to SetHardwareWatchpointWithIndex(),
and do that only if the newly requested watchpoint is different
from the one being set previously. This ensures that the disable-enable
logic of LLDB does not clear watchpoint hit status for the remaining
threads.
This also involves refactoring of watchpoint logic. With the old logic,
clearing watchpoint involved wiping dr6 & dr7, and setting it setting
dr{0..3} & dr7. With the new logic, only enable bit is cleared
from dr7, and the remaining bits are cleared/overwritten while setting
new watchpoint.
Differential Revision: https://reviews.llvm.org/D70025
NetBSD ptrace interface does not populate watchpoints to newly-created
threads. Solve this via copying the watchpoints from the current thread
when new thread is reported via TRAP_LWP.
Add a test that verifies that when the user does not have permissions
to set watchpoints on NetBSD, the 'watchpoint set' errors out gracefully
and thread monitoring does not crash on being unable to copy watchpoints
to new threads.
Differential Revision: https://reviews.llvm.org/D70023
Implement major improvements to multithreaded program support. Notably,
support tracking new and exited threads, associate signals and events
with correct threads and support controlling individual threads when
resuming.
Firstly, use PT_SET_EVENT_MASK to enable reporting of created and exited
threads via SIGTRAP. Handle TRAP_LWP events to keep track
of the currently running threads.
Secondly, update the signal (both generic and SIGTRAP) handling code
to account for per-thread signals correctly. Signals delivered
to the whole process are reported on all threads, while per-thread
signals and events are reported only to the specific thread.
The remaining threads are marked as 'stopped with no reason'. Note that
NetBSD always stops all threads on debugger events.
Thirdly, implement the ability to set every thread as running, stopped
or single-stepping separately while continuing the process. This also
provides the ability to send a signal to the whole process or to one
of its thread while resuming.
Differential Revision: https://reviews.llvm.org/D70022
Summary:
Adds support for doing range-based for-loops on LLDB's VariableList and
modernises all the index-based for-loops in LLDB where possible.
Reviewers: labath, jdoerfert
Reviewed By: labath
Subscribers: JDevlieghere, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D70668
Summary:
LLDB's ASTDumper is just a clone of Clang's ASTDumper but with some scary code and
some unrelated functionality (like dumping name/attributes of types). This removes LLDB's ASTDumper
and replaces its uses with the `ClangUtils::DumpDecl` method that just calls Clang's ASTDumper
and returns the result as a string.
The few uses where we just want a textual representation of a type (which will print their name/attributes but not
dump any AST) are now also in ClangUtil under a `ToString` name until we find a better home for them.
Reviewers: labath
Reviewed By: labath
Subscribers: mgorny, JDevlieghere, lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D70663
Muhammad Omair Javaid