class. If we try to unwind a stack frame to find a caller stack
frame, and we fail to get a valid-looking frame, AND if the UnwindPlan
we used is an assembly-inspection based UnwindPlan, then we should
throw away the assembly-inspection UnwindPlan and try unwinding with
the architectural default UnwindPlan.
This code path won't be taken if eh_frame unwind instructions are available -
lldb will always prefer those once it's off the zeroth frame.
The problem I'm trying to fix here is the class of unwind failures that
happen when we have hand-written assembly on the stack, with no eh_frame,
and lldb's assembly parser fails to understand the assembly. People usually
write their hand-written assembly to follow the frame-pointer-preserving
conventions of the platform so the architectural default UnwindPlan will
often work. We won't have the spill location for most of the non-volatile
registers if we fall back to this, but it's better than stopping the unwind
prematurely.
This is a bit of a tricky change that I believe is correct, but if we get
unwinds that go of into the weeds / unwind bogus frames at the end of the
stack, I'll need to revisit it.
<rdar://problem/16099440>
llvm-svn: 201839
specify a list of functions which should be treated as trap handlers.
This will be primarily useful to people working in non-user-level
process debugging - kernels and other standalone environments.
For most people, the trap handler functions provided by the Platform
plugin will be sufficient.
<rdar://problem/15835846>, <rdar://problem/15982682>
llvm-svn: 201386
aka asynchronous signal handlers, which subclasses should fill
in as appropriate. For most Unix user process environments,
the one entry in this list is _sigtramp. For bare-board and
kernel environments, there will be different sets of trap
handlers.
The unwinder needs to know when a frame is a trap handler
because the rules it enforces for the frame "above" the
trap handler is different from most middle-of-the-stack frames.
<rdar://problem/15835846>
llvm-svn: 201300
Fixes http://llvm.org/bugs/show_bug.cgi?id=18656.
Note this exposes a failure on Linux of
TestInferiorAssert.test_inferior_asserting_disassemble, similar to how
it fails on FreeBSD. I'll file a bug for this next. We're now getting
another frame beyond where we used to prior to this fix, so the fix is
exposing failures in previosly not-reachable frames.
Much thanks to Jason Molenda, who had much to do with helping figure
out where unwinding was breaking.
llvm-svn: 200600
The former will set the Address object's offset to the load address value if
it is not present in any section; the latter will only set the Address object
if the load addr is contained in one of its sections.
<rdar://problem/15135987>
llvm-svn: 198469
its stack frame is a constructed, fake thing that may not conform
correctly to these rules. This fixes a problem where lldb couldn't
backtrace past an asynchronous signal handler (_sigtramp) frame on
a stack on Mac OS X.
<rdar://problem/15035673>
llvm-svn: 198450
The original code was not completely correct, but a form of
this check is necessary to avoid an infinite recursion on
some unwind cases where a function unwinds to itself with the
same CFA. Ashok thought the recursion would be caught in
RegisterContextLLDB but this one isn't - we still need it here.
<rdar://problem/15664282>
llvm-svn: 197761
In those set of patches, Ashok changed Module::ResolveSymbolContextForAddress
so that if it failed to find a symbol for a pc, it could back up
the pc value by 1 and re-search for a symbol.
His change to RegisterContextLLDB.cpp partially duplicates that
behavior but it also removes the separate case where we find a
Symbol for the pc address but it's the wrong symbol -- we need to
handle this as well as the lookup-by-pc-finds-no-symbol case.
The most obvious fallout from this regression was that lldb on
Mac OS X couldn't backtrace past __assert_rtn() which tail-calls
abort(). e.g.
(lldb) bt
* thread #1: tid = 0x5d6ea1, 0x00007fff8ee80866 libsystem_kernel.dylib`__pthread_kill + 10, queue = 'com.apple.main-thread', stop reason = signal SIGABRT
* frame #0: 0x00007fff8ee80866 libsystem_kernel.dylib`__pthread_kill + 10
frame #1: 0x00007fff8eb5835c libsystem_pthread.dylib`pthread_kill + 92
frame #2: 0x00007fff8852ab1a libsystem_c.dylib`abort + 125
frame #3: 0x00007fff884f49bf libsystem_c.dylib`__assert_rtn + 321
frame #4: 0x0000000100000f2c a.out`main + 124
(lldb) dis -c 3 -s 0x7fff884f49b3
libsystem_c.dylib`__assert_rtn + 309:
0x7fff884f49b3: movq %rax, -0x11b96242(%rip) ; gCRAnnotations + 8
0x7fff884f49ba: callq 0x7fff8854fd2c ; symbol stub for: abort
libsystem_c.dylib`basename:
0x7fff884f49bf: pushq %rbp
(lldb)
in this case, __assert_rtn() is immediately followed by basename() and
the changes in r190812 didn't back up the pc value to get the correct
function name / unwind info.
<rdar://problem/15367233>
llvm-svn: 197655
<rdar://problem/15314403>
This patch adds a new lldb_private::SectionLoadHistory class that tracks what shared libraries were loaded given a process stop ID. This allows us to keep a history of the sections that were loaded for a time T. Many items in history objects will rely upon the process stop ID in the future.
llvm-svn: 196557
pure virtual base class and made StackFrame a subclass of that. As
I started to build on top of that arrangement today, I found that it
wasn't working out like I intended. Instead I'll try sticking with
the single StackFrame class -- there's too much code duplication to
make a more complicated class hierarchy sensible I think.
llvm-svn: 193983
defines a protocol that all subclasses will implement. StackFrame
is currently the only subclass and the methods that Frame vends are
nearly identical to StackFrame's old methods.
Update all callers to use Frame*/Frame& instead of pointers to
StackFrames.
This is almost entirely a mechanical change that touches a lot of
the code base so I'm committing it alone. No new functionality is
added with this patch, no new subclasses of Frame exist yet.
I'll probably need to tweak some of the separation, possibly moving
some of StackFrame's methods up in to Frame, but this is a good
starting point.
<rdar://problem/15314068>
llvm-svn: 193907
To make this work this patch extends LLDB to:
- Explicitly track the link_map address for each module. This is effectively the module handle, not sure why it wasn't already being stored off anywhere. As an extension later, it would be nice if someone were to add support for printing this as part of the modules list.
- Allow reading the per-thread data pointer via ptrace. I have added support for Linux here. I'll be happy to add support for FreeBSD once this is reviewed. OS X does not appear to have __thread variables, so maybe we don't need it there. Windows support should eventually be workable along the same lines.
- Make DWARF expressions track which module they originated from.
- Add support for the DW_OP_GNU_push_tls_address DWARF opcode, as generated by gcc and recent versions of clang. Earlier versions of clang (such as 3.2, which is default on Ubuntu right now) do not generate TLS debug info correctly so can not be supported here.
- Understand the format of the pthread DTV block. This is where it gets tricky. We have three basic options here:
1) Call "dlinfo" or "__tls_get_addr" on the inferior and ask it directly. However this won't work on core dumps, and generally speaking it's not a good idea for the debugger to call functions itself, as it has the potential to not work depending on the state of the target.
2) Use libthread_db. This is what GDB does. However this option requires having a version of libthread_db on the host cross-compiled for each potential target. This places a large burden on the user, and would make it very hard to cross-debug from Windows to Linux, for example. Trying to build a library intended exclusively for one OS on a different one is not pleasant. GDB sidesteps the problem and asks the user to figure it out.
3) Parse the DTV structure ourselves. On initial inspection this seems to be a bad option, as the DTV structure (the format used by the runtime to manage TLS data) is not in fact a kernel data structure, it is implemented entirely in useerland in libc. Therefore the layout of it's fields are version and OS dependent, and are not standardized.
However, it turns out not to be such a problem. All OSes use basically the same algorithm (a per-module lookup table) as detailed in Ulrich Drepper's TLS ELF ABI document, so we can easily write code to decode it ourselves. The only question therefore is the exact field layouts required. Happily, the implementors of libpthread expose the structure of the DTV via metadata exported as symbols from the .so itself, designed exactly for this kind of thing. So this patch simply reads that metadata in, and re-implements libthread_db's algorithm itself. We thereby get cross-platform TLS lookup without either requiring third-party libraries, while still being independent of the version of libpthread being used.
Test case included.
llvm-svn: 192922
to build out the symbol table as addresses are used, and implements
the mechanism for ELF to add stripped symbols from eh_frame.
Uses this mechanism to allow disassembly for addresses corresponding
to stripped symbols for ELF, and provide hooks to implement this for
PE COFF.
Also removes eSymbolContextTailCall in favor of an option for
ResolveSymbolContextForAddress for consistency with the documentation
for eSymbolContextEverything. Essentially, this is just an option for
interpreting the so_addr.
llvm-svn: 191307
default-at-first-instruction UnwindPlan if we're at the beginning of a function and
the ABI can provide us with an UnwindPlan to get out of there before falling back
to the generic architectural default UnwindPlan (which usually assumes that the stack
has already been set up.)
Update the FuncUnwinders methods to gracefully handle the case where an assembly
profiler may not be available.
Fix a bug where FuncUnwinders::GetUnwindPlanArchitectureDefaultAtFunctionEntry was
returning the wrong UnwindPlan to its caller.
llvm-svn: 191262
Specifically, allows the unwinder to handle the case where sc.function
gets resolved with a pc that is one past the address range of the function
(consistent with a tail call). However, there is no matching symbol.
Adds eSymbolContextTailCall to provide callers with control over the scope
of symbol resolution and to allow ResolveSymbolContextForAddress to handle
tail calls since this routine is common to unwind and disassembly.
llvm-svn: 191102
for the frame is one past the address range of the calling function.
- Lowers the fix from RegisterContextLLDB for use with disassembly
- Fixes one of three issues in the disassembly test in TestInferiorAssert.py
Also adds documentation that explains the resolution depths and interface.
Note: This change affects the resolution scope for eSymbolContextFunction
without impacting the performance of eSymbolContextSymbol.
Thanks to Matt Kopec for his review.
llvm-svn: 190812
RegisterContextLLDB::SavedLocationForRegister to cache the pc and
sp register numbers -- if lldb is debugging multiple Targets of
different architectures, this will be incorrect. If these were
to be cached anywhere, it would have to be up in the Target.
llvm-svn: 186651
and -fomit-frame-pointer.
- Parses eh_frame FDEs to determine the function address and size so that
the call frame parsing can continue.
Note: This code path is specific to ELF and PECOFF, because ObjectFileMachO
uses LCT_FunctionStarts to efficiently populate the symbol table.
Thanks to Jason Molenda for the review!
llvm-svn: 186585
A long time ago we start with clang types that were created by the symbol files and there were many functions in lldb_private::ClangASTContext that helped. Later we create ClangASTType which contains a clang::ASTContext and an opauque QualType, but we didn't switch over to fully using it. There were a lot of places where we would pass around a raw clang_type_t and also pass along a clang::ASTContext separately. This left room for error.
This checkin change all type code over to use ClangASTType everywhere and I cleaned up the interfaces quite a bit. Any code that was in ClangASTContext that was type related, was moved over into ClangASTType. All code that used these types was switched over to use all of the new goodness.
llvm-svn: 186130
the link register save location being in the link register - in which case we
should iterate down the stack, not recursively try to find the lr in the current
frame over and over.
<rdar://problem/13932954>
llvm-svn: 183282
defines a Return Address register (e.g. lr on arm) but the RA register
hasn't been saved anywhere yet -- it is still in a live reg.
<rdar://problem/13503130>
llvm-svn: 179431
LLDB is crashing when logging is enabled from lldb-perf-clang. This has to do with the global destructor chain as the process and its threads are being torn down.
All logging channels now make one and only one instance that is kept in a global pointer which is never freed. This guarantees that logging can correctly continue as the process tears itself down.
llvm-svn: 178191
StackFrame assumes m_sc is additive, but m_sc can lose its target. So now the SymbolContext::Clear() method takes a bool that indicates if the target should be cleared. Modified all existing code to properly set the bool argument.
llvm-svn: 175953
Major fixed to allow reading files that are over 4GB. The main problems were that the DataExtractor was using 32 bit offsets as a data cursor, and since we mmap all of our object files we could run into cases where if we had a very large core file that was over 4GB, we were running into the 4GB boundary.
So I defined a new "lldb::offset_t" which should be used for all file offsets.
After making this change, I enabled warnings for data loss and for enexpected implicit conversions temporarily and found a ton of things that I fixed.
Any functions that take an index internally, should use "size_t" for any indexes and also should return "size_t" for any sizes of collections.
llvm-svn: 173463
- remove unused members
- add NO_PEDANTIC to selected Makefiles
- fix return values (removed NULL as needed)
- disable warning about four-char-constants
- remove unneeded const from operator*() declaration
- add missing lambda function return types
- fix printf() with no format string
- change sizeof to use a type name instead of variable name
- fix Linux ProcessMonitor.cpp to be 32/64 bit friendly
- disable warnings emitted by swig-generated C++ code
Patch by Matt Kopec!
llvm-svn: 169645
allowed volatile registers to be returned up the stack. That leads
to unexpected/incorrect values provided to the user and we need to
avoid that.
<rdar://problem/12714247>
llvm-svn: 168123
Full UnwindPlan is trying to do an impossible unwind; in that case
invalidate the Full UnwindPlan and replace it with the architecture
default unwind plan.
This is a scenario that happens occasionally with arm unwinds in
particular; the instruction analysis based full unwindplan can
mis-parse the functions and the stack walk stops prematurely. Now
we can do a simpleminded frame-chain walk to find the caller frame
and continue the unwind. It's not ideal but given the complicated
nature of analyzing the arm functions, and the lack of eh_frame
information on iOS, it is a distinct improvement and fixes some
long-standing problems with the unwinder on that platform.
This is fixing <rdar://problem/12091421>. I may re-use this
invalidate feature in the future if I can identify other cases where
the full unwindplan's unwind information is clearly incorrect.
This checkin also includes some cleanup for the volatile register
definition in the arm ABI plugin for <rdar://problem/10652166>
although work remains to be done for that bug.
llvm-svn: 166757
must push something on the stack for a function call or not. In
x86, the stack pointer is decremented when the caller's pc is saved
on the stack. In arm, the stack pointer and frame pointer don't
necessarily have to change for a function call, although most
functions need to use some stack space during their execution.
Use this information in the RegisterContextLLDB to detect invalid
unwind scenarios more accurately.
<rdar://problem/12348574>
llvm-svn: 166005
Make breakpoint setting by file and line much more efficient by only looking for inlined breakpoint locations if we are setting a breakpoint in anything but a source implementation file. Implementing this complex for a many reasons. Turns out that parsing compile units lazily had some issues with respect to how we need to do things with DWARF in .o files. So the fixes in the checkin for this makes these changes:
- Add a new setting called "target.inline-breakpoint-strategy" which can be set to "never", "always", or "headers". "never" will never try and set any inlined breakpoints (fastest). "always" always looks for inlined breakpoint locations (slowest, but most accurate). "headers", which is the default setting, will only look for inlined breakpoint locations if the breakpoint is set in what are consudered to be header files, which is realy defined as "not in an implementation source file".
- modify the breakpoint setting by file and line to check the current "target.inline-breakpoint-strategy" setting and act accordingly
- Modify compile units to be able to get their language and other info lazily. This allows us to create compile units from the debug map and not have to fill all of the details in, and then lazily discover this information as we go on debuggging. This is needed to avoid parsing all .o files when setting breakpoints in implementation only files (no inlines). Otherwise we would need to parse the .o file, the object file (mach-o in our case) and the symbol file (DWARF in the object file) just to see what the compile unit was.
- modify the "SymbolFileDWARFDebugMap" to subclass lldb_private::Module so that the virtual "GetObjectFile()" and "GetSymbolVendor()" functions can be intercepted when the .o file contenst are later lazilly needed. Prior to this fix, when we first instantiated the "SymbolFileDWARFDebugMap" class, we would also make modules, object files and symbol files for every .o file in the debug map because we needed to fix up the sections in the .o files with information that is in the executable debug map. Now we lazily do this in the DebugMapModule::GetObjectFile()
Cleaned up header includes a bit as well.
llvm-svn: 162860
when you want to find the caller's saved pc, you look up the return address
register and use that. On arm, for instance, this would be the contents of
the link register (lr).
If the eh_frame CIE defines an RA, record that fact in the UnwindPlan.
When we're finding a saved register, if it's the pc, lok for the location
of the return address register instead.
<rdar://problem/12062310>
llvm-svn: 162167
a shared pointer to ease some memory management issues with a patch
I'm working on.
The main complication with using SPs for these objects is that most
methods that build up an UnwindPlan will construct a Row to a given
instruction point in a function, then add additional regsaves in
the next instruction point to that row and push it again. A little
care is needed to not mutate the previous instruction point's Row
once these are switched to being held behing shared pointers.
llvm-svn: 160214
which require a valid CFA address to create a stack frame. On connecting
to just-starting-up hardware we may have a stack pointer/frame pointer of 0
but we should still create a stack frame so other code in lldb can retrieve
register values via a stackframe.
llvm-svn: 151796
an unwind because RegisterContextLLDB::InitializeZerothFrame() would
create a minimal stack frame to fetch the pc value of the current
instruction. This proved fragile when another section of code was
trying to create the first stack frame and UnwindLLDB called
RegisterContextLLDB which tried to create its minimal stack frame.
Instead, get the live RegisterContext, retrieve the pc value from
the registers, and create an Address object from that.
llvm-svn: 151714
I started work on being able to add symbol files after a debug session
had started with a new "target symfile add" command and quickly ran into
problems with stale Address objects in breakpoint locations that had
lldb_private::Section pointers into modules that had been removed or
replaced. This also let to grabbing stale modules from those sections.
So I needed to thread harded the Address, Section and related objects.
To do this I modified the ModuleChild class to now require a ModuleSP
on initialization so that a weak reference can created. I also changed
all places that were handing out "Section *" to have them hand out SectionSP.
All ObjectFile, SymbolFile and SymbolVendors were inheriting from ModuleChild
so all of the find plug-in, static creation function and constructors now
require ModuleSP references instead of Module *.
Address objects now have weak references to their sections which can
safely go stale when a module gets destructed.
This checkin doesn't complete the "target symfile add" command, but it
does get us a lot clioser to being able to do such things without a high
risk of crashing or memory corruption.
llvm-svn: 151336
objects for the backlink to the lldb_private::Process. The issues we were
running into before was someone was holding onto a shared pointer to a
lldb_private::Thread for too long, and the lldb_private::Process parent object
would get destroyed and the lldb_private::Thread had a "Process &m_process"
member which would just treat whatever memory that used to be a Process as a
valid Process. This was mostly happening for lldb_private::StackFrame objects
that had a member like "Thread &m_thread". So this completes the internal
strong/weak changes.
Documented the ExecutionContext and ExecutionContextRef classes so that our
LLDB developers can understand when and where to use ExecutionContext and
ExecutionContextRef objects.
llvm-svn: 151009
due to RTTI worries since llvm and clang don't use RTTI, but I was able to
switch back with no issues as far as I can tell. Once the RTTI issue wasn't
an issue, we were looking for a way to properly track weak pointers to objects
to solve some of the threading issues we have been running into which naturally
led us back to std::tr1::weak_ptr. We also wanted the ability to make a shared
pointer from just a pointer, which is also easily solved using the
std::tr1::enable_shared_from_this class.
The main reason for this move back is so we can start properly having weak
references to objects. Currently a lldb_private::Thread class has a refrence
to its parent lldb_private::Process. This doesn't work well when we now hand
out a SBThread object that contains a shared pointer to a lldb_private::Thread
as this SBThread can be held onto by external clients and if they end up
using one of these objects we can easily crash.
So the next task is to start adopting std::tr1::weak_ptr where ever it makes
sense which we can do with lldb_private::Debugger, lldb_private::Target,
lldb_private::Process, lldb_private::Thread, lldb_private::StackFrame, and
many more objects now that they are no longer using intrusive ref counted
pointer objects (you can't do std::tr1::weak_ptr functionality with intrusive
pointers).
llvm-svn: 149207
Fixed an ARM backtracing issue where if the previous frame was a thumb
function and it was a tail call so that the current frame returned to
an address that would fall into the next function, we would use the
next function as the basis for how we unwound the previous frame's
registers and of course get things wrong. We now fix the PC code
address using the current ABI plug-in, and the ARM ABI plug-in has
been modified to correctly fix the code address. So when we do the
symbol context lookup, instead of taking an address like 0x1001 and
decrementing 1, and looking up the symbol context for a frame, we
now correctly fix 0x1001 to 0x1000, then decrement that by 1 to
get the correct symbol context.
I added a bunch more logging to "log enable lldb uwnind" to help
us in the future. We now log the PC, FP and SP (if they are available),
and we also dump the "active_row" that we find for unwinding a frame.
llvm-svn: 147747
1 -- an address pointing off into non-executable memory -- don't
abort the unwind. We'll use the ABI's default UnwindPlan to try
to get out of frame 1 and on many platforms with a standard frame
chain stack layout we can get back on track and get a valid frame
2. This preserves the lldb behavior to-date; the change last week
to require the memory region to be executable broke it.
I'd like to mark this frame specially when displayed to the user;
I tried to override the places where the frame's pc value is returned
to change it to a sentinel value (e.g. LLDB_INVALID_ADDRESS) but
couldn't get that to work cleanly so I backed that part out for
now. When this happens we'll often miss one of the user's actual
frames, the one that's of most interest to the user, so I'd like
to make this visually distinctive.
Note that a frame in non-executable memory region is only allowed
for frame 1. After that we should be solid on the unwind and any
pc address in non-executable memory indicates a failure and we
should stop unwinding.
llvm-svn: 146723
dispatch functions that are implemented in hand-written assembly.
There is also hand-written eh_frame instructions for unwinding
from these functions.
Normally we don't use eh_frame instructions for the currently
executing function, prefering the assembly instruction profiling
method. But in these hand-written dispatch functions, the
profiling is doomed and we should use the eh_frame instructions.
Unfortunately there's no easy way to flag/extend the eh_frame/debug_frame
sections to annotate if the unwind instructions are accurate at
all addresses ("asynchronous") or if they are only accurate at locations
that can throw an exception ("synchronous" and the normal case for
gcc/clang generated eh_frame/debug_frame CFI).
<rdar://problem/10508134>
llvm-svn: 146551
Check that the pc value for frames up the stack is in a
mapped+executable region of memory.
Check that the stack pointer for frames up the stack is
in a mapped+readable region of memory.
If the unwinder ever makes a mistake walking the stack,
these checks will help to keep it from going too far into
the weeds.
These aren't fixing any bugs that I know of, but they
add extra robustness to a complicated task.
llvm-svn: 146478
if this is a mapped/executable region of memory. If it isn't, we've jumped
through a bad pointer and we know how to unwind the stack correctly based
on the ABI.
Previously I had 0x0 special cased but if you jumped to 0x2 on x86_64 one
frame would be skipped because the unwinder would try using the x86_64
ArchDefaultUnwindPlan which relied on the rbp.
Fixes <rdar://problem/10508291>
llvm-svn: 146477
RegisterContextLLDBs it contains.
Previously RegisterContextLLDB objects had a pointer to their "next"
frame down the stack. e.g. stack starts at frame 0; frame 3 has a
pointer to frame 2. This is used to retreive callee saved register
values. When debugging an inferior that has blown out its own stack,
however, this could result in lldb blowing out its own stack while
recursing down to retrieve register values.
RegisterContextLLDB no longer has a pointer to its next frame; it
has a reference to the UnwindLLDB which contains it. When it needs
to retrieve a reg value, it asks the UnwindLLDB for that reg value
and UnwindLLDB iterates through the frames until it finds a location.
llvm-svn: 143423
with the same CFA (or an alternating sequence between two CFA values) to catch a handful of
unwind cases where lldb will inf loop trying to unwind a stack.
llvm-svn: 142331
the arm emulate instruction unwinder so you can leave it
on by default and not be overwhelmed. Set verbose mode to
get the full story on how the unwindplans were created.
llvm-svn: 139897
UnwindPlan for unwinding from the first instruction of an otherwise
unknown function call (GetUnwindPlanArchitectureDefaultAtFunctionEntry()).
Update RegisterContextLLDB::GetFullUnwindPlanForFrame() to detect the
case of a frame 0 at address 0x0 which indicates that we jumped through
a NULL function pointer. Use the ABI's FunctionEntryUnwindPlan to
find the caller frame.
These changes make it so lldb can identify the calling frame correctly
in code like
int main ()
{
void (*f)(void) = 0;
f();
}
llvm-svn: 139760
register names when dumping variable locations and location lists. Also did
some cleanup where "int" types were being used for "lldb::RegisterKind"
values.
llvm-svn: 138988
darwin (not sure about other platforms).
Modified the communication and connection classes to not require the
BytesAvailable function. Now the "Read(...)" function has a timeout in
microseconds.
Fixed a lot of assertions that were firing off in certain cases and replaced
them with error output and code that can deal with the assertion case.
llvm-svn: 133224
respective ABI plugins as they were plug-ins that supplied ABI specfic info.
Also hookep up the UnwindAssemblyInstEmulation so that it can generate the
unwind plans for ARM.
Changed the way ABI plug-ins are handed out when you get an instance from
the plug-in manager. They used to return pointers that would be mananged
individually by each client that requested them, but now they are handed out
as shared pointers since there is no state in the ABI objects, they can be
shared.
llvm-svn: 131193
into some cleanup I have been wanting to do when reading/writing registers.
Previously all RegisterContext subclasses would need to implement:
virtual bool
ReadRegisterBytes (uint32_t reg, DataExtractor &data);
virtual bool
WriteRegisterBytes (uint32_t reg, DataExtractor &data, uint32_t data_offset = 0);
There is now a new class specifically designed to hold register values:
lldb_private::RegisterValue
The new register context calls that subclasses must implement are:
virtual bool
ReadRegister (const RegisterInfo *reg_info, RegisterValue ®_value) = 0;
virtual bool
WriteRegister (const RegisterInfo *reg_info, const RegisterValue ®_value) = 0;
The RegisterValue class must be big enough to handle any register value. The
class contains an enumeration for the value type, and then a union for the
data value. Any integer/float values are stored directly in an appropriate
host integer/float. Anything bigger is stored in a byte buffer that has a length
and byte order. The RegisterValue class also knows how to copy register value
bytes into in a buffer with a specified byte order which can be used to write
the register value down into memory, and this does the right thing when not
all bytes from the register values are needed (getting a uint8 from a uint32
register value..).
All RegiterContext and other sources have been switched over to using the new
regiter value class.
llvm-svn: 131096
inline contexts when the deepest most block is not inlined.
Added source path remappings to the lldb_private::Target class that allow it
to remap paths found in debug info so we can find source files that are elsewhere
on the current system.
Fixed disassembly by function name to disassemble inline functions that are
inside other functions much better and to show enough context before the
disassembly output so you can tell where things came from.
Added the ability to get more than one address range from a SymbolContext
class for the case where a block or function has discontiguous address ranges.
llvm-svn: 130044
ArchDefaultUnwindPlan plug-in interfaces are now cached per architecture
instead of being leaked for every frame.
Split the ArchDefaultUnwindPlan_x86 into ArchDefaultUnwindPlan_x86_64 and
ArchDefaultUnwindPlan_i386 interfaces.
There were sporadic crashes that were due to something leaking or being
destroyed when doing stack crawls. This patch should clear up these issues.
llvm-svn: 125541
bool RegisterContextLLDB::GetPC (addr_t& pc);
to:
bool RegisterContextLLDB::ReadPC (addr_t& pc);
To avoid confusion with the GetPC() function that is part of the
lldb_private::RegisterContext:
uint64_t RegisterContext::GetPC (uint64_t fail_value);
Bad things could happen if the two got intermixed and the wrong one got
called.
Fixed inifinite loop detection by watching for two frames where the
RegisterContextLLDB::CursorSP contains the same start_pc and cfa.
llvm-svn: 123673
a method:
void RegisterContext::InvalidateIfNeeded (bool force);
Each time this function is called, when "force" is false, it will only call
the pure virtual "virtual void RegisterContext::InvalideAllRegisters()" if
the register context's stop ID doesn't match that of the process. When the
stop ID doesn't match, or "force" is true, the base class will clear its
cached registers and the RegisterContext will update its stop ID to match
that of the process. This helps make it easier to correctly flush the register
context (possibly from multiple locations depending on when and where new
registers are availabe) without inadvertently clearing the register cache
when it doesn't need to be.
Modified the ProcessGDBRemote plug-in to be much more efficient when it comes
to:
- caching the expedited registers in the stop reply packets (we were ignoring
these before and it was causing us to read at least three registers every
time we stopped that were already supplied in the stop reply packet).
- When a thread has no stop reason, don't keep asking for the thread stopped
info. Prior to this fix we would continually send a qThreadStopInfo packet
over and over when any thread stop info was requested. We now note the stop
ID that the stop info was requested for and avoid multiple requests.
Cleaned up some of the expression code to not look for ClangExpressionVariable
objects up by name since they are now shared pointers and we can just look for
the exact pointer match and avoid possible errors.
Fixed an bug in the ValueObject code that would cause children to not be
displayed.
llvm-svn: 123127
an issue with the way the UnwindLLDB was handing out RegisterContexts: it
was making shared pointers to register contexts and then handing out just
the pointers (which would get put into shared pointers in the thread and
stack frame classes) and cause double free issues. MallocScribble helped to
find these issues after I did some other cleanup. To help avoid any
RegisterContext issue in the future, all code that deals with them now
returns shared pointers to the register contexts so we don't end up with
multiple deletions. Also now that the RegisterContext class doesn't require
a stack frame, we patched a memory leak where a StackFrame object was being
created and leaked.
Made the RegisterContext class not have a pointer to a StackFrame object as
one register context class can be used for N inlined stack frames so there is
not a 1 - 1 mapping. Updates the ExecutionContextScope part of the
RegisterContext class to never return a stack frame to indicate this when it
is asked to recreate the execution context. Now register contexts point to the
concrete frame using a concrete frame index. Concrete frames are all of the
frames that are actually formed on the stack of a thread. These concrete frames
can be turned into one or more user visible frames due to inlining. Each
inlined stack frame has the exact same register context (shared via shared
pointers) as any parent inlined stack frames all the way up to the concrete
frame itself.
So now the stack frames and the register contexts should behave much better.
llvm-svn: 122976
0 mid-stack, stop backtracing.
SectionLoadList.cpp (ResolveLoadAddress): Don't assert on an
out-of-range address, just return an invalid Address object.
The unwinder may be passing in invalid addresses on the final
stack frame and the assert is a problem.
llvm-svn: 122386
RegisterContext* - normally this is retrieved from the ExecutionContext's
StackFrame but when we need to evaluate an expression while creating
the stack frame list this can be a little tricky.
Add DW_OP_deref_size, needed for the _sigtramp FDE expression.
Add support for processing DWARF expressions in RegisterContextLLDB.
Update callers to DWARFExpression::Evaluate.
llvm-svn: 119885
needs to use the current pc and current offset in two ways: To
determine which function we are currently executing, and the decide
how much of that function has executed so far. For the former use,
we need to back up the saved pc value by one byte if we're going to
use the correct function's unwind information -- we may be executing
a CALL instruction at the end of a function and the following instruction
belongs to a new function, or we may be looking at unwind information
which only covers the call instruction and not the subsequent instruction.
But when we're talking about deciding which row of an UnwindPlan to
execute, we want to use the actual byte offset in the function, not the
byte offset - 1.
Right now RegisterContextLLDB is tracking both the "real" offset and
an "offset minus one" and different parts of the class have to know
which one to use and they need to be updated/set in tandem. I want
to revisit this at some point.
The second change made in looking up eh_frame information; it was
formerly done by looking for the start address of the function we
are currently executing. But it is possible to have unwind information
for a function which only covers a small section of the function's
address range. In which case looking up by the start pc value may not
find the eh_frame FDE.
The hand-written _sigtramp() unwind info on Mac OS X, which covers
exactly one instruction in the middle of the function, happens to
trigger both of these issues.
I still need to get the UnwindPlan runner to handle arbitrary dwarf
expressions in the FDE but there's a good chance it will be easy to
reuse the DWARFExpression class to do this.
llvm-svn: 118882
I only did a tiny bit of testing; in the one case I tried changing the
contents of a radar in the middle of a stack and it was still current in
the live register context so it filtered down to frame 0 and was handed
over to the live register set RegisterContext. I need to test a case
where a register is saved on the stack in memory before I check this
one off.
llvm-svn: 118486
FuncUnwinders object if the eh_frame section was missing
from an objfile. Worked fine on x86_64 but on i386 where
eh_frame is unusual, that resulted in the arch default
UnwindPlan being used all the time instead of picking up
an assembly profile based unwindplan.
llvm-svn: 118467
don't crash if we disable logging when some code already has a copy of the
logger. Prior to this fix, logs were handed out as pointers and if they were
held onto while a log got disabled, then it could cause a crash. Now all logs
are handed out as shared pointers so this problem shouldn't happen anymore.
We are also using our new shared pointers that put the shared pointer count
and the object into the same allocation for a tad better performance.
llvm-svn: 118319
fixed them. Added DISALLOW_COPY_AND_ASSIGN to classes that should
not be bitwise copied. Added default initializers for member
variables that weren't being initialized in the ctor. Fixed a few
shadowed local variable mistakes.
llvm-svn: 118240
RegisterContextLLDB holds a reference to the SymbolContext
in the vector of Cursors that UnwindLLDB maintains. Switch
UnwindLLDB to hold a vector of shared pointers of Cursors
so this reference doesn't become invalid.
Correctly falling back from the "fast" UnwindPlan to the
"full" UnwindPlan when additional registers need to be
retrieved.
llvm-svn: 118218
loaded/parsed. Should add timers to this eventually.
Delay getting a full UnwindPlan if it's possible to unwind with
just a fast UnwindPlan. This keeps us from reading the eh_frame
section unless we hit something built -fomit-frame pointer or we
hit a frame with no symbol (read: no start address) available.
It doesn't look like it is correctly falling back to using the
full UnwindPlan to provide additional registers that the fast
UnwindPlan doesn't supply; e.g. go to the middle of a stack and
ask for r12 and it will show you the value of r12 in frame 0.
That's a bug for tomorrow.
llvm-svn: 117361
gets to be a problem if you have a unbounded stack walk.
Fix the CFA sanity checks. Add one to the arch default UnwindPlan run which was giving
one extra stack frame on the main thread. Fix a couple of logging lines that had their
argument order incorrect.
llvm-svn: 117350
prologue profiling.
Change the log print statements to elide the thread number, make
some of them only print when IsLogVerbose().
Add a couple of sanity checks for impossible CFA values so backtraces
don't go too far off into the weeds.
llvm-svn: 117343
Not yet enabled as the default unwinder but there are no known
backtrace problems with the code at this point.
Added 'log enable lldb unwind' to help diagnose backtrace problems;
this output needs a little refining but it's a good first step.
eh_frame information is currently read unconditionally - the code
is structured to allow this to be delayed until it's actually needed.
There is a performance hit when you have to parse the eh_frame
information for any largeish executable/library so it's necessary
to avoid if possible.
It's confusing having both the UnwindPlan::RegisterLocation struct
and the RegisterConextLLDB::RegisterLocation struct, I need to rename
one of them.
The writing of registers isn't done in the RegisterConextLLDB subclass
yet; neither is the running of complex DWARF expressions from eh_frame
(e.g. used for _sigtramp on Mac OS X).
llvm-svn: 117256
Jason Molenda