Fix an off-by-one error in the utility function used to extract the
dynamic class info. This resulted in a buffer overflow in the inferior
which interrupted our utility function.
Differential revision: https://reviews.llvm.org/D128377
A copy/paste error in GetClassInfoUtilityFunction resulted in the wrong
utility function being returned: copyRealizedClassList instead of
getRealizedClassList_trylock.
Differential revision: https://reviews.llvm.org/D128378
Add a setting to configure how LLDB parses dynamic Objective-C class
metadata. By default LLDB will choose the most appropriate method for
the target OS.
Differential revision: https://reviews.llvm.org/D128312
Recent revisions of the Objective-C runtime changed
objc_debug_class_getNameRaw() in a way that no longer triggers lazy
names to be instantiated. This has the unintended side-effect of making
generic bridged Swift classes, such as _SwiftDeferredNSDictionary<U,V>
to become invisible to the Objective-C runtime.
This patch detects this situation and forces the names to be
instantiated by calling class_getName() and discarding the result before
calling objc_debug_class_getNameRaw() again.
Many thanks to Mike Ash for outlining the solution and Adrian for
authoring the downstream patch.
rdar://95245318
Differential revision: https://reviews.llvm.org/D128306
In order to avoid stranding the Objective-C runtime lock, we switched
from objc_copyRealizedClassList to its non locking variant
objc_copyRealizedClassList_nolock. Not taking the lock was relatively
safe because we run this expression on one thread only, but it was still
possible that someone was in the middle of modifying this list while we
were trying to read it. Worst case that would result in a crash in the
inferior without side-effects and we'd unwind and try again later.
With the introduction of macOS Ventura, we can use
objc_getRealizedClassList_trylock instead. It has semantics similar to
objc_copyRealizedClassList_nolock, but instead of not locking at all,
the function returns if the lock is already taken, which avoids the
aforementioned crash without stranding the Objective-C runtime lock.
Because LLDB gets to allocate the underlying memory we also avoid
stranding the malloc lock.
rdar://89373233
Differential revision: https://reviews.llvm.org/D127252
Clang is adding a feature to ObjC code generation, where instead of calling
objc_msgSend directly with an object & selector, it generates a stub that
gets passed only the object and the stub figures out the selector.
This patch adds support for following that dispatch method into the implementation
function.
In https://reviews.llvm.org/D118972 I increased this buffer to be
big enough to import 261,144 classes but this is a lot more than
we currently have, an allocating a too-large buffer can add memory
pressure even if it's only for a short time. Reduce the size of
this memory buffer to big enough to import 163,840 classes. I'll
probably move to a scheme where we read the objc classes in chunks,
with a smaller buffer and multiple inferior function calls.
rdar://91275493
Fix undefined behavior in AppleObjCRuntimeV2 where we were left shifting
a signed value. This also removes redundant casts of unobfuscated to
uint64_t which it already is.
rdar://91242879
Differential revision: https://reviews.llvm.org/D123098
Report warnings and errors through events instead of printing directly
the to the debugger's error stream. By using events, IDEs such as Xcode
can report these issues in the UI instead of having them show up in the
debugger console.
The new diagnostic events are handled by the default event loop. If a
diagnostic is reported while nobody is listening for the new event
types, it is printed directly to the debugger's error stream.
Differential revision: https://reviews.llvm.org/D121511
The log channel was changed from Types to Commands in
a007a6d84471bb956abe10974cac3066799f583f:
- Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS | LIBLLDB_LOG_TYPES));
+ Log *log = GetLog(LLDBLog::Process | LLDBLog::Commands);
Identifiers with __ anywhere are reserved. I picked this up via the
bugprone-reserved-identifier clang-tidy check but -Wreserved-identifier will
also flag these uses as well.
Differential Revision: https://reviews.llvm.org/D119915
iOS systems are getting near this limit; double itfrom a 150kb
buffer to a 300kb buffer, which is freed after processing the
list of classes.
rdar://88454594
Differential Revision: https://reviews.llvm.org/D118972
Most of our code was including Log.h even though that is not where the
"lldb" log channel is defined (Log.h defines the generic logging
infrastructure). This worked because Log.h included Logging.h, even
though it should.
After the recent refactor, it became impossible the two files include
each other in this direction (the opposite inclusion is needed), so this
patch removes the workaround that was put in place and cleans up all
files to include the right thing. It also renames the file to LLDBLog to
better reflect its purpose.
Use libobjc.A.dylib as a sentinel to detect situations where we're
reading libraries from process memory instead of the shared cache.
Differential revision: https://reviews.llvm.org/D117623
Don't try to get a class descriptor for a pointer that doesn't look like
a tagged pointer. Also print addresses as fixed-width hex and update the
test.
- Use formatv to print the addresses.
- Add check for 0x0 which is treated as an invalid address.
- Use a an address that's less likely to be interpreted as a real
tagged pointer.
Improve error handling for the lang objc tagged-pointer info. Rather
than failing silently, report an error if we couldn't convert an
argument to an address or resolve the class descriptor.
(lldb) lang objc tagged-pointer info 0xbb6404c47a587764
error: could not get class descriptor for 0xbb6404c47a587764
(lldb) lang objc tagged-pointer info n1
error: could not convert 'n1' to a valid address
Differential revision: https://reviews.llvm.org/D112945
Fix a potential nullptr dereference in AppleObjCRuntimeV2 by checking
the result of GetClassInfoUtilityFunction and returning a failure if
it's null.
The DynamicClassInfoExtractor was already doign the right thing, but the
SharedCacheClassInfoExtractor was missing this check.
There is no reason why this function should be returning a ConstString.
While modifying these files, I also fixed several instances where
GetPluginName and GetPluginNameStatic were returning different strings.
I am not changing the return type of GetPluginNameStatic in this patch, as that
would necessitate additional changes, and this patch is big enough as it is.
Differential Revision: https://reviews.llvm.org/D111877
The objc_clsopt_v16_t struct does not match up with the macOS/iOS15
dyld_shared_cache ObjC runtime structures. A struct field was seemingly
omitted.
Differential revision: https://reviews.llvm.org/D110477
In all these years, we haven't found a use for this function (it has
zero callers). Lets just remove the boilerplate.
Differential Revision: https://reviews.llvm.org/D109600
It looks like recent CoreFoundation builds strip the non-public symbol
that we were looking for to find the 2 boolean "classes". The public
symbol is of course there, and it contains the address of the private
one. If we don't find the private symbol directly, go through a memory
read at the public symbol's location instead.
When we check whether the Objective-C SPI is available, we need to check
for the mangled symbol name. Unlike `objc_copyRealizedClassList`, which
is C exported, the `nolock` variant is not.
Differential revision: https://reviews.llvm.org/D105136
Avoid standing the Objective-C runtime lock by calling
objc_copyRealizedClassList_nolock instead of objc_copyRealizedClassList.
We already guarantee that no other threads can run while we're running
this utility expression, similar to when we parse the data ourselves
from the gdb_objc_realized_classes struct.
Worst case this will crash if the list is getting edited, which won't do
any harm and we'll just try again later.
Differential revision: https://reviews.llvm.org/D104951
This converts a default constructor's member initializers into C++11
default member initializers. This patch was automatically generated with
clang-tidy and the modernize-use-default-member-init check.
$ run-clang-tidy.py -header-filter='lldb' -checks='-*,modernize-use-default-member-init' -fix
This is a mass-refactoring patch and this commit will be added to
.git-blame-ignore-revs.
Differential revision: https://reviews.llvm.org/D103483
The C headers are deprecated so as requested in D102845, this is replacing them
all with their (not deprecated) C++ equivalent.
Reviewed By: shafik
Differential Revision: https://reviews.llvm.org/D103084
A long time ago LLDB wanted to start using StringRef instead of
C-Strings/ConstString but was blocked by the fact that the StringRef constructor
that takes a C-string was asserting that the C-string isn't a nullptr. To
workaround this, D24697 introduced a special function called `withNullAsEmpty`
and that's what LLDB (and only LLDB) started to use to build StringRefs from
C-strings.
A bit later it seems that `withNullAsEmpty` was declared too awkward to use and
instead the assert in the StringRef constructor got removed (see D24904). The
rest of LLDB was then converted to StringRef by just calling the now perfectly
usable implicit constructor.
However, all the calls to `withNullAsEmpty` just remained and are now just
strange artefacts in the code base that just look out of place. It's also
curiously a LLDB-exclusive function and no other project ever called it since
it's introduction half a decade ago.
This patch removes all uses of `withNullAsEmpty`. The follow up will be to
remove the function from StringRef.
Reviewed By: JDevlieghere
Differential Revision: https://reviews.llvm.org/D102597
Also remove a superfluous semicolon after the braces for a switch
statement (that wasn't warned about).
Differential Revision: https://reviews.llvm.org/D100447
This reverts commit 602ab188a7.
The patch replicated an lldbassert for a certain type of NSNumber for tagged
pointers. This really shouldn't be an assert since we don't do anything wrong
with these numbers, we just don't print a summary. So this patch changed the
lldbassert to a log message in reverting the revert.
This reverts commit 4d9039c8dc.
This is causing the greendragon bots to fail most of the time when
running TestNSDictionarySynthetic.py. Reverting until Jim has a chance
to look at this on Monday. Running the commands from that test from
the command line, it fails 10-13% of the time on my desktop.
This is a revert of Jim's changes in https://reviews.llvm.org/D99694
On macOS Catalina, calling objc_debug_class_getNameRaw on some of the
ISA pointers returns NULL, causing us to crash and unwind before reading
all the Objective-C classes. This does not happen on macOS Big Sur.
Account for that possibility and skip the class when that happens.
The ObjC runtime offers both signed & unsigned tagged pointer value
accessors to tagged pointer providers, but lldb's tagged pointer
code only implemented the unsigned one. This patch adds an
emulation of the signed one.
The motivation for doing this is that NSNumbers use the signed
accessor (they are always signed) and we need to follow that in our
summary provider or we will get incorrect values for negative
NSNumbers.
The data-formatter-objc test file had NSNumber examples (along with lots of other
goodies) but the NSNumber values weren't tested. So I also added
checks for those values to the test.
I also did a quick audit of the other types in that main.m file, and
it looks like pretty much all the other values are either intermediates
or are tested.
Differential Revision: https://reviews.llvm.org/D99694
Move UpdateISAToDescriptorMap into ClassInfoExtractor so that all the
formerly public functions can be private and remain an implementation
detail of the extractor.
Differential revision: https://reviews.llvm.org/D99448
This adds the consistency I promised in D99315 between how we read the
class info from the Objective-C runtime and the shared cache. (NFC)
Differential revision: https://reviews.llvm.org/D99446
Generic classes in Swift have their name instantiated on request, since
the vast majority never need it, and it just wastes time and memory.
This results in LLDB being unable to determine the dynamic type of these
Swift objects.
The main issues is that lazily named classes are not added to the
gdb_objc_realized_classes hashtable. This means the class count in the
table doesn't change when a class is realized and LLDB doesn't know it
needs to re-parse the class info. But even if it did, the classes are
not in the hash table.
The first change in this patch is that we read
objc_debug_realized_class_generation_count and re-parse the class info
when the count changes.
The second change in this patch is that we use
objc_copyRealizedClassList (if available) to get all realized classes
from the runtime.
Unfortunately, objc_copyRealizedClassList calls _dyld_objc_class_count
in its implementation. As we know, the Objective-C parsing code might
get called before dyld is fully initialized, resulting in crashes or
even a stranded lock. Therefore we only use objc_copyRealizedClassList
when we know it's safe to do so by checking libSystemInitialized in
dyld_all_image_infos.
As a result, it's possible that the first time we read the Objective-C
runtime we are forced to use gdb_objc_realized_classes. This should be
fine, as there should be no lazily named classes at this point.
Subsequent queries will detect the change in realized class generation
count and use objc_copyRealizedClassList.
This patch keeps the old behavior when objc_copyRealizedClassList or
objc_debug_realized_class_generation_count are not available.
Differential revision: https://reviews.llvm.org/D99315
The objc_debug_isa_class_mask magic value that the objc runtime vends
is now initialized using a static initializer instead of a constant
value. The runtime plugin itself will be initialized before the value
is computed and as a result, the cache will get the wrong value.
Making the creation of the NonPointerIsaCache fully lazy fixes this.
The comment for ValueType claims that all values <1 are errors, but
not all switch statements take this into account. This patch
introduces an explicit Error case and deletes all default: cases, so
we get warned about incomplete switch coverage.
https://reviews.llvm.org/D96537
Jonas Devlieghere