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* Unwind: Add a stack scanning mechanism to support win32 unwindingPavel Labath2019-09-271-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Windows unwinding is weird. The unwind rules do not (always) describe the precise layout of the stack, but rather expect the debugger to scan the stack for something which looks like a plausible return address, and the unwind based on that. The reason this works somewhat reliably is because the the unwinder also has access to the frame sizes of the functions on the stack. This allows it (in most cases) to skip function pointers in local variables or function arguments, which could otherwise be mistaken for return addresses. Implementing this kind of unwind mechanism in lldb was a bit challenging because we expect to be able to statically describe (in the UnwindPlan) structure, the layout of the stack for any given instruction. Giving a precise desription of this is not possible, because it requires correlating information from two functions -- the pushed arguments to a function are considered a part of the callers stack frame, and their size needs to be considered when unwinding the caller, but they are only present in the unwind entry of the callee. The callee may end up being in a completely different module, or it may not even be possible to determine it statically (indirect calls). This patch implements this functionality by introducing a couple of new APIs: SymbolFile::GetParameterStackSize - return the amount of stack space taken up by parameters of this function. SymbolFile::GetOwnFrameSize - the size of this function's frame. This excludes the parameters, but includes stuff like local variables and spilled registers. These functions are then used by the unwinder to compute the estimated location of the return address. This address is not always exact, because the stack may contain some additional values -- for instance, if we're getting ready to call a function then the stack will also contain partially set up arguments, but we will not know their size because we haven't called the function yet. For this reason the unwinder will crawl up the stack from the return address position, and look for something that looks like a possible return address. Currently, we assume that something is a valid return address if it ends up pointing to an executable section. All of this logic kicks in when the UnwindPlan sets the value of CFA as "isHeuristicallyDetected", which is also the final new API here. Right now, only SymbolFileBreakpad implements these APIs, but in the future SymbolFilePDB will use them too. Differential Revision: https://reviews.llvm.org/D66638 llvm-svn: 373072
* Fix PC adjustment in StackFrame::GetSymbolContextJoseph Tremoulet2019-08-021-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Update StackFrame::GetSymbolContext to mirror the logic in RegisterContextLLDB::InitializeNonZerothFrame that knows not to do the pc decrement when the given frame is a signal trap handler frame or the parent of one, because the pc may not follow a call in these frames. Accomplish this by adding a behaves_like_zeroth_frame field to lldb_private::StackFrame, set to true for the zeroth frame, for signal handler frames, and for parents of signal handler frames. Also add logic to propagate the signal handler flag from UnwindPlan to the FrameType on the RegisterContextLLDB it generates, and factor out a helper to resolve symbol and address range for an Address now that we need to invoke it in four places. Reviewers: jasonmolenda, clayborg, jfb Reviewed By: jasonmolenda Subscribers: labath, dexonsmith, lldb-commits Tags: #lldb Differential Revision: https://reviews.llvm.org/D64993 llvm-svn: 367691
* [NFC] Remove ASCII lines from commentsJonas Devlieghere2019-04-101-8/+0
| | | | | | | | | | | | | | | | | | | | | | | A lot of comments in LLDB are surrounded by an ASCII line to delimit the begging and end of the comment. Its use is not really consistent across the code base, sometimes the lines are longer, sometimes they are shorter and sometimes they are omitted. Furthermore, it looks kind of weird with the 80 column limit, where the comment actually extends past the line, but not by much. Furthermore, when /// is used for Doxygen comments, it looks particularly odd. And when // is used, it incorrectly gives the impression that it's actually a Doxygen comment. I assume these lines were added to improve distinguishing between comments and code. However, given that todays editors and IDEs do a great job at highlighting comments, I think it's worth to drop this for the sake of consistency. The alternative is fixing all the inconsistencies, which would create a lot more churn. Differential revision: https://reviews.llvm.org/D60508 llvm-svn: 358135
* Bring Doxygen comment syntax in sync with LLVM coding style.Adrian Prantl2019-03-111-2/+2
| | | | | | This changes '@' prefix to '\'. llvm-svn: 355841
* Update the file headers across all of the LLVM projects in the monorepoChandler Carruth2019-01-191-4/+3
| | | | | | | | | | | | | | | | | to reflect the new license. We understand that people may be surprised that we're moving the header entirely to discuss the new license. We checked this carefully with the Foundation's lawyer and we believe this is the correct approach. Essentially, all code in the project is now made available by the LLVM project under our new license, so you will see that the license headers include that license only. Some of our contributors have contributed code under our old license, and accordingly, we have retained a copy of our old license notice in the top-level files in each project and repository. llvm-svn: 351636
* Remove header grouping comments.Jonas Devlieghere2018-11-111-4/+0
| | | | | | | | This patch removes the comments grouping header includes. They were added after running IWYU over the LLDB codebase. However they add little value, are often outdates and burdensome to maintain. llvm-svn: 346626
* [x86] Fix issues with a realigned stack in MSVC compiled applicationsAleksandr Urakov2018-10-301-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This patch fixes issues with a stack realignment. MSVC maintains two frame pointers (`ebx` and `ebp`) for a realigned stack - one is used for access to function parameters, while another is used for access to locals. To support this the patch: - adds an alternative frame pointer (`ebx`); - considers stack realignment instructions (e.g. `and esp, -32`); - along with CFA (Canonical Frame Address) which point to the position next to the saved return address (or to the first parameter on the stack) introduces AFA (Aligned Frame Address) which points to the position of the stack pointer right after realignment. AFA is used for access to registers saved after the realignment (see the test); Here is an example of the code with the realignment: ``` struct __declspec(align(256)) OverAligned { char c; }; void foo(int foo_arg) { OverAligned oa_foo = { 1 }; auto aaa_foo = 1234; } void bar(int bar_arg) { OverAligned oa_bar = { 2 }; auto aaa_bar = 5678; foo(1111); } int main() { bar(2222); return 0; } ``` and here is the `bar` disassembly: ``` push ebx mov ebx, esp sub esp, 8 and esp, -100h add esp, 4 push ebp mov ebp, [ebx+4] mov [esp+4], ebp mov ebp, esp sub esp, 200h mov byte ptr [ebp-200h], 2 mov dword ptr [ebp-4], 5678 push 1111 ; foo_arg call j_?foo@@YAXH@Z ; foo(int) add esp, 4 mov esp, ebp pop ebp mov esp, ebx pop ebx retn ``` Reviewers: labath, zturner, jasonmolenda, stella.stamenova Reviewed By: jasonmolenda Subscribers: abidh, lldb-commits Tags: #lldb Differential Revision: https://reviews.llvm.org/D53435 llvm-svn: 345577
* Remove dependencies from Utility to Core and Target.Zachary Turner2017-02-141-1/+1
| | | | | | | | | | With this patch, the only dependency left is from Utility to Host. After this is broken, Utility will finally be standalone. Differential Revision: https://reviews.llvm.org/D29909 llvm-svn: 295088
* *** This commit represents a complete reformatting of the LLDB source codeKate Stone2016-09-061-221/+216
| | | | | | | | | | | | | | | | | | | | | | | *** to conform to clang-format’s LLVM style. This kind of mass change has *** two obvious implications: Firstly, merging this particular commit into a downstream fork may be a huge effort. Alternatively, it may be worth merging all changes up to this commit, performing the same reformatting operation locally, and then discarding the merge for this particular commit. The commands used to accomplish this reformatting were as follows (with current working directory as the root of the repository): find . \( -iname "*.c" -or -iname "*.cpp" -or -iname "*.h" -or -iname "*.mm" \) -exec clang-format -i {} + find . -iname "*.py" -exec autopep8 --in-place --aggressive --aggressive {} + ; The version of clang-format used was 3.9.0, and autopep8 was 1.2.4. Secondly, “blame” style tools will generally point to this commit instead of a meaningful prior commit. There are alternatives available that will attempt to look through this change and find the appropriate prior commit. YMMV. llvm-svn: 280751
* [LLDB] Fix Clang-tidy modernize-use-override warnings in some headers in ↵Eugene Zelenko2015-10-171-30/+28
| | | | | | | | source/Plugins/Process/Utility; other minor fixes. Differential Revision: http://reviews.llvm.org/D13830 llvm-svn: 250593
* Hoist the RegisterNumber class out of RegisterContextLLDB and makeJason Molenda2015-01-101-159/+1
| | | | | | | | | | | | | | | it more generally available. Add checks to UnwindAssembly_x86::AugmentUnwindPlanFromCallSite() so that it won't try to augment an UnwindPlan that already describes the function epilogue. Add a test case for backtracing out of _sigtramp on Darwin systems. This could probably be adapted to test the same thing on linux/bsd but the function names of sigtramp and kill are probably platform specific and I'm not sure what they should be. llvm-svn: 225578
* A pretty big overhaul of the TryFallbackUnwindPlan method inJason Molenda2014-11-131-0/+27
| | | | | | | | | | | | RegisterContextLLDB. I have core files of half a dozen tricky unwind situations on x86/arm and they're all working pretty much correctly at this point, but we'll need to keep an eye out for unwinder regressions for a little while; it's tricky to get these heuristics completely correct in all unwind situations. <rdar://problem/18937193> llvm-svn: 221866
* Add an alternative CFA type.Justin Hibbits2014-11-121-0/+4
| | | | | | | | | | | | | | | | | | | Summary: PowerPC handles the stack chain with the current stack pointer being a pointer to the backchain (CFA). LLDB currently has no way of handling this, so this adds a "CFA is dereferenced from a register" type. Discussed with Jason Molenda, who also provided the initial patch for this. Reviewers: jasonmolenda Reviewed By: jasonmolenda Subscribers: emaste, lldb-commits Differential Revision: http://reviews.llvm.org/D6182 llvm-svn: 221788
* Add an operator== to the RegisterNumber class; it simplifiesJason Molenda2014-11-111-1/+37
| | | | | | RegisterContextLLDB a bit more in a few places. llvm-svn: 221677
* Add a RegisterNumber class to RegisterContextLLDB.h and start usingJason Molenda2014-11-081-0/+111
| | | | | | | | | | | | | | | | | | | | | | | it in RegisterContext.cpp. There's a lot of bookkeeping code in RegisterContextLLDB where it has to convert between different register numbering schemes and it makes some methods like SavedLocationForRegister very hard to read or maintain. Abstract all of the details about different register numbering systems for a given register into this new class to make it easier to understand what the method is doing. Also add register name printing to all of the logging -- that's easy to get now that I've got an object to represent the register numbers. There were some gnarly corner cases of this method that I believe I've translated correctly - initial testing looks good but it's possible I missed a corner case, especially with architectures which uses a link-register aka return address register like arm32/arm64. Basic behavior is correct but there are a lot of corner casese that are handled in this method ... llvm-svn: 221577
* Back out r221229 -- instead of trying to identify the end of the unwind,Jason Molenda2014-11-041-7/+0
| | | | | | | | | | | | | | | | | let's let lldb try the arch default unwind every time but not destructively -- it doesn't permanently replace the main unwind method for that function from now on. This fix is for <rdar://problem/18683658>. I tested it against Ryan Brown's go program test case and also a collection of core files of tricky unwind scenarios <rdar://problem/15664282> <rdar://problem/15835846> <rdar://problem/15982682> <rdar://problem/16099440> <rdar://problem/17364005> <rdar://problem/18556719> that I've fixed over the last 6-9 months. llvm-svn: 221238
* After we've completed a full backtrace, we'll have one frame whichJason Molenda2014-11-041-0/+7
| | | | | | | | | | | | | | | | is "invalid" -- it is past the end of the stack trace. Add a new method IsCompletedStackWalk() so we can tell if an invalid stack frame is from a complete backtrace or if it might be worth re-trying the last unwind with a different method. This fixes the unwinder problems Ryan Brown was having with go programs. The unwinder can (under the right circumstances) still destructively replace unwind plans permanently - I'll work on that in a different patch. <rdar://problem/18683658> llvm-svn: 221229
* RegisterContextLLDB::InitializeNonZerothFrame had a bit of code toJason Molenda2014-09-021-0/+6
| | | | | | | | | | | | | | | | | | | | detct unwind loops but there was a code path through there (using architecture default unwind plans) that didn't do the check, and could end up with an infinite loop unwind. Move that code into a separate method and call it from both places where it is needed. Also remove the use of ABI::FunctionCallsChangeCFA in that check. I thought about it a lot and none of the architecutres that we're supporting today can have a looping CFA. Since the unwinder isn't using ABI::FunctionCallsChangeCFA() and ABI::StackUsesFrames(), and the unwinder was the only reason those methods exists, I removed them from the ABI and all its plugins. <rdar://problem/17364005> llvm-svn: 216992
* Replace uint32_t by lldb::RegisterKing in register context API.Jean-Daniel Dupas2014-07-021-2/+2
| | | | llvm-svn: 212172
* Add a new idea of a "fallback" UnwindPlan to the RegisterContextLLDBJason Molenda2014-02-211-3/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Add a new target setting, trap-handler-names, where a user canJason Molenda2014-02-141-0/+13
| | | | | | | | | | | | 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
* The Platform base class now maintains a list of trap handlersJason Molenda2014-02-131-2/+2
| | | | | | | | | | | | | | | | 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
* Fix for failure to unwind Linux stack frames with call in final position.Todd Fiala2014-02-011-0/+4
| | | | | | | | | | | | | | | 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
* Don't enforce ABI stack alignment rules on the sigtramp frame --Jason Molenda2014-01-031-0/+3
| | | | | | | | | | 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
* After discussing with Chris Lattner, we require C++11, so lets get rid of ↵Greg Clayton2013-04-181-1/+1
| | | | | | the macros and just use C++11. llvm-svn: 179805
* <rdar://problem/13069948>Greg Clayton2013-01-251-2/+2
| | | | | | | | | | | | 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
* A change in how we search for saved register values unintentionallyJason Molenda2012-11-161-1/+1
| | | | | | | | | 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
* Add a new capability to RegisterContextLLDB: To recognize when theJason Molenda2012-10-261-17/+21
| | | | | | | | | | | | | | | | | | | | | | | | | 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
* <rdar://problem/10434005>Greg Clayton2012-03-141-1/+1
| | | | | | | Prepare LLDB to be built with C++11 by hiding all accesses to std::tr1 behind macros that allows us to easily compile for either C++. llvm-svn: 152698
* Switching back to using std::tr1::shared_ptr. We originally switched awayGreg Clayton2012-01-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | 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
* When we're unwinding out of frame 0 and we end up with a bogus frameJason Molenda2011-12-161-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | 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
* Restructure the relationship between UnwindLLDB and theJason Molenda2011-11-011-36/+24
| | | | | | | | | | | | | | | | | | 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
* Add code to RegisterContextLLDB::InitializeNonZerothFrame to detect a ↵Jason Molenda2011-10-181-0/+3
| | | | | | | | | multiple stack frames 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
* While implementing unwind information using UnwindAssemblyInstEmulation I ranGreg Clayton2011-05-091-8/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 &reg_value) = 0; virtual bool WriteRegister (const RegisterInfo *reg_info, const RegisterValue &reg_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
* Fixed the LLDB build so that we can have private types, private enums andGreg Clayton2011-03-241-2/+2
| | | | | | | | public types and public enums. This was done to keep the SWIG stuff from parsing all sorts of enums and types that weren't needed, and allows us to abstract our API better. llvm-svn: 128239
* All UnwindPlan objects are now passed around as shared pointers.Greg Clayton2011-02-151-6/+9
| | | | | | | | | | | | | 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
* Avoid infinite loops in stack backtraces and renamed:Greg Clayton2011-01-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | 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
* Put more smarts into the RegisterContext base class. Now the base class hasGreg Clayton2011-01-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Spelling changes applied from lldb_spelling.diffs from Bruce Mitchener.Greg Clayton2011-01-081-2/+2
| | | | | | Thanks Bruce! llvm-svn: 123083
* Fixed issues with RegisterContext classes and the subclasses. There wasGreg Clayton2011-01-061-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* I'm not thrilled with how I structured this but RegisterContextLLDBJason Molenda2010-11-121-4/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Silence a bunch of clang warnings.Benjamin Kramer2010-11-101-1/+1
| | | | llvm-svn: 118710
* Implement RegisterContext::WriteRegisterBytes in RegisterContextLLDB.Jason Molenda2010-11-091-1/+1
| | | | | | | | | | | 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
* Handle the case where no eh_frame section is present.Jason Molenda2010-11-041-5/+6
| | | | | | | | | | | | | 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
* Add an unwind log Printf to note when an eh_frame section isJason Molenda2010-10-261-3/+14
| | | | | | | | | | | | | | | | | 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
* Check in the native lldb unwinder. Jason Molenda2010-10-251-0/+177
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
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