Commit Graph

598 Commits

Author SHA1 Message Date
Michał Górny 1ff411295f [lldb] Improve debugging 32-bit programs on NetBSD/amd64
Implement detection of ELF binary format, and support for i386 register
context on amd64 when a 32-bit executable is being debugged.  This is
roughly based on the code from Linux.

Differential Revision: https://reviews.llvm.org/D73974
2020-02-07 17:48:33 +01:00
Michał Górny 5cc817be75 [lldb] Introduce i386 support in NetBSD Process plugin
Introduce support for i386 platform that is shared with amd64
in the same plugin.  The concept is partially based on the Linux
implementation.

The plugin tries to reuse as much code as possible.  As a result, i386
register enums are mapped into amd64 values and those are used in actual
code.  The code for accessing FPU and debug registers is shared,
although general-purpose register layouts do not match between the two
kernel APIs and need to be #ifdef-ed.

This layout will also make it possible to add support for debugging
32-bit programs on amd64 with minimal added code.

In order for this to work, I had to add missing data for debug registers
on i386.

Differential Revision: https://reviews.llvm.org/D73802
2020-02-05 13:31:06 +01:00
Benjamin Kramer adcd026838 Make llvm::StringRef to std::string conversions explicit.
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.

This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.

This doesn't actually modify StringRef yet, I'll do that in a follow-up.
2020-01-28 23:25:25 +01:00
Jonas Devlieghere 2bc38ab3d0 [lldb/Breakpoint] Recogize hardware breakpoints as such
Recognize hardware breakpoints as breakpoints instead of just mach
exceptions. The mach exception is the same for watch and breakpoints, so
we have to try each to figure out which is which.

Differential revision: https://reviews.llvm.org/D73401
2020-01-24 19:24:25 -08:00
Raphael Isemann 808142876c [lldb][NFC] Fix all formatting errors in .cpp file headers
Summary:
A *.cpp file header in LLDB (and in LLDB) should like this:
```
//===-- TestUtilities.cpp -------------------------------------------------===//
```
However in LLDB most of our source files have arbitrary changes to this format and
these changes are spreading through LLDB as folks usually just use the existing
source files as templates for their new files (most notably the unnecessary
editor language indicator `-*- C++ -*-` is spreading and in every review
someone is pointing out that this is wrong, resulting in people pointing out that this
is done in the same way in other files).

This patch removes most of these inconsistencies including the editor language indicators,
all the different missing/additional '-' characters, files that center the file name, missing
trailing `===//` (mostly caused by clang-format breaking the line).

Reviewers: aprantl, espindola, jfb, shafik, JDevlieghere

Reviewed By: JDevlieghere

Subscribers: dexonsmith, wuzish, emaste, sdardis, nemanjai, kbarton, MaskRay, atanasyan, arphaman, jfb, abidh, jsji, JDevlieghere, usaxena95, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D73258
2020-01-24 08:52:55 +01:00
Jonas Devlieghere e194d89012 [lldb/MachO] "Fix" intentional out-of-bounds error (NFC)
Remove the hack that populates the cpsr register in the gpr struct by
writing past the end of the array. This was tripping up ASan.

Patch by: Reva Cuthbertson
2019-12-18 12:54:04 -08:00
Jonas Devlieghere 3011d55f72 [lldb/Host] Use cmakedefine01 for LLDB_ENABLE_POSIX
Rename LLDB_DISABLE_POSIX to LLDB_ENABLE_POSIX and use cmakedefine01 for
consistency.
2019-12-13 10:00:59 -08:00
Davide Italiano 294ef766e8 [RegisterContext] Remove now unneded vestiges. 2019-11-13 14:53:13 -08:00
Michał Górny 6eca4f4691 [lldb] [Process/NetBSD] Add register info for missing register sets
Add info for all register sets supported in NetBSD, particularly for all
registers 'expected' by LLDB.  This is necessary in order to fix
python_api/lldbutil/iter/TestRegistersIterator.py test that currently
fails due to missing names of register sets (None).

This copies fpreg descriptions from Linux, and combines Linux' AVX
and MPX registers into a single XState group, to fit NetBSD register
group design.  Technically, we do not support MPX registers
at the moment but gdb-remote insists on passing their errors anyway,
and if we do not include it in any group, they end up in a separate
anonymous group that breaks the test.

While at it, swap the enums for XState and DBRegs to match register set
ordering.

This also adds a few consts to the lldb-x86-register-enums.h to provide
more consistency between user registers and debug registers.

Differential Revision: https://reviews.llvm.org/D69667
2019-11-04 19:36:58 +01:00
Guilherme Andrade e46c6644db [lldb] Fix offset intersection bug between MPX and AVX registers
Summary:
This change increases the offset of MPX registers (by 128) so they
do not overlap with the offset associated with AVX registers. That was
causing MPX data in GDBRemoteRegisterContext::m_reg_data to get overwritten.

Reviewers: labath

Reviewed By: labath

Subscribers: JDevlieghere, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D68874
2019-10-31 10:58:17 +01:00
Adrian Prantl 1ad655e255 Modernize the rest of the Find.* API (NFC)
This patch removes the size_t return value and the append parameter
from the remainder of the Find.* functions in LLDB's internal API. As
in the previous patches, this is motivated by the fact that these
parameters aren't really used, and in the case of the append parameter
were frequently implemented incorrectly.

Differential Revision: https://reviews.llvm.org/D69119

llvm-svn: 375160
2019-10-17 19:56:40 +00:00
Jason Molenda 7dd7a36075 Add arm64_32 support to lldb, an ILP32 codegen
that runs on arm64 ISA targets, specifically 
Apple watches.


Differential Revision: https://reviews.llvm.org/D68858

llvm-svn: 375032
2019-10-16 19:14:49 +00:00
Aleksandr Urakov 30c2441a32 [Windows] Use information from the PE32 exceptions directory to construct unwind plans
This patch adds an implementation of unwinding using PE EH info. It allows to
get almost ideal call stacks on 64-bit Windows systems (except some epilogue
cases, but I believe that they can be fixed with unwind plan disassembly
augmentation in the future).

To achieve the goal the CallFrameInfo abstraction was made. It is based on the
DWARFCallFrameInfo class interface with a few changes to make it less
DWARF-specific.

To implement the new interface for PECOFF object files the class PECallFrameInfo
was written. It uses the next helper classes:

- UnwindCodesIterator helps to iterate through UnwindCode structures (and
  processes chained infos transparently);
- EHProgramBuilder with the use of UnwindCodesIterator constructs EHProgram;
- EHProgram is, by fact, a vector of EHInstructions. It creates an abstraction
  over the low-level unwind codes and simplifies work with them. It contains
  only the information that is relevant to unwinding in the unified form. Also
  the required unwind codes are read from the object file only once with it;
- EHProgramRange allows to take a range of EHProgram and to build an unwind row
  for it.

So, PECallFrameInfo builds the EHProgram with EHProgramBuilder, takes the ranges
corresponding to every offset in prologue and builds the rows of the resulted
unwind plan. The resulted plan covers the whole range of the function except the
epilogue.

Reviewers: jasonmolenda, asmith, amccarth, clayborg, JDevlieghere, stella.stamenova, labath, espindola

Reviewed By: jasonmolenda

Subscribers: leonid.mashinskiy, emaste, mgorny, aprantl, arichardson, MaskRay, lldb-commits, llvm-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D67347

llvm-svn: 374528
2019-10-11 09:03:29 +00:00
Vedant Kumar 4805c817c3 StopInfo/Mach: Delete PPC support
LLDB appears to have at least partial support for PPC, but PPC on Mach
isn't a thing AFAIK.

Differential Revision: https://reviews.llvm.org/D68661

llvm-svn: 374114
2019-10-08 20:47:44 +00:00
Vedant Kumar 07c5f2a9b0 StopInfo/Mach: Use early-exits, reflow messy comments, NFCI
llvm-svn: 374106
2019-10-08 19:40:13 +00:00
Davide Italiano 293ec1e16a [RegisterContextDarwin_arm64] Include the headers for getsysctlbyname.
This code is only used under __arm64__, use the correct guard.

<rdar://problem/55916729>

llvm-svn: 373509
2019-10-02 19:20:21 +00:00
Pavel Labath a8b284eeec Unwind: Add a stack scanning mechanism to support win32 unwinding
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
2019-09-27 12:10:06 +00:00
Martin Storsjo e37b882421 [LLDB] Fix typo in RegisterContextDarwin_arm64
In these cases, the register number should be calculated from
fpu_d0, not fpu_s0.

Differential Revision: https://reviews.llvm.org/D67892

llvm-svn: 372738
2019-09-24 12:20:21 +00:00
Alex Langford 5b2b38e053 [Target] Move InferiorCall to Process
Summary:
InferiorCall is only ever used in Process, and it is not specific to
POSIX. By moving it to Process, we can remove all dependencies on plugins from
Process. Moving InferiorCall to Process seems to achieve this quite well.
Additionally, the name InferiorCall is a little vague now, so we rename
it something a bit more specific.

Reviewers: JDevlieghere, clayborg, compnerd, labath

Subscribers: lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D67472

llvm-svn: 371796
2019-09-13 00:02:05 +00:00
Alex Langford 1b385a1802 [Plugins/Process] Remove direct use of ClangASTContext from InferiorCallPOSIX
Summary:
InferiorCallPOSIX directly grabs a ClangASTContext from the Target it
has and does no error checking. I don't think these functions have a
reason to know about clang specifically. Additionally, using
`GetScratchTypeSystemForLanguage` forces us to do error checking since
it returns an Expected.

Differential Revision: https://reviews.llvm.org/D67427

llvm-svn: 371654
2019-09-11 20:36:28 +00:00
Omair Javaid 1da33fd4ef [ARM64] Simplify RegisterInfos_arm64.h with macro based RegisterInfo array
This patches paves way for upcoming SVE RegisterInfo definitions. This is cosmetic change which allows us to define ARM64 RegisterInfo using macros.

In future we ll have define two different RegisterInfos to choose between SVE vs non-SVE RegisterInfo with decision being made at thread creation.

Differential Revision: https://reviews.llvm.org/D66934

llvm-svn: 370644
2019-09-02 11:53:29 +00:00
Pavel Labath e588b8b664 DWARFExpression: Simplify class interface
Summary:
The DWARFExpression methods have a lot of arguments. This removes two of
them by removing the ability to slice the expression via two offset+size
parameters. This is a functionality that it is not always needed, and
when it is, we already have a different handy way of slicing a data
extractor which we can use instead.

Reviewers: JDevlieghere, clayborg

Subscribers: aprantl, lldb-commits

Differential Revision: https://reviews.llvm.org/D66745

llvm-svn: 370027
2019-08-27 07:49:41 +00:00
Jonas Devlieghere 3af3f1e8e2 [Utility] Reimplement RegularExpression on top of llvm::Regex
Originally I wanted to remove the RegularExpression class in Utility and
replace it with llvm::Regex. However, during that transition I noticed
that there are several places where need the regular expression string.
So instead I propose to keep the RegularExpression class and make it a
thin wrapper around llvm::Regex.

This patch also removes the workaround for empty regular expressions.
The result is that we are now (more or less) POSIX conformant.

Differential revision: https://reviews.llvm.org/D66174

llvm-svn: 369153
2019-08-16 21:25:36 +00:00
Jonas Devlieghere b6946a2d12 Fix warning: suggest braces around initialization of subobject
This patch adds braces to the DEFINE_XMM macro.

llvm-svn: 368782
2019-08-14 01:25:10 +00:00
Aaron Smith 5146a9ea5d Initial support for native debugging of x86/x64 Windows processes
Summary: Thanks to Hui Huang and the reviewers for all the help with this patch.

Reviewers: labath, Hui, jfb, clayborg, amccarth

Reviewed By: labath

Subscribers: amccarth, compnerd, dexonsmith, mgorny, jfb, teemperor, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D63165

llvm-svn: 368759
2019-08-13 22:18:01 +00:00
Haibo Huang 575ce5da7d Small format fix
Differential Revision: https://reviews.llvm.org/D66034

llvm-svn: 368497
2019-08-09 22:59:56 +00:00
Haibo Huang a20a59d87a Detects whether RESOURCE_TYPE_IO is defined.
Summary: This fixes lldb build on macOS SDK prior to 10.12.

Reviewers: JDevlieghere

Subscribers: lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D66034

llvm-svn: 368496
2019-08-09 22:47:46 +00:00
Joseph Tremoulet 31e6dbe1c6 Fix PC adjustment in StackFrame::GetSymbolContext
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
2019-08-02 16:53:42 +00:00
JF Bastien 268a83e39c [NFC] avoid AlignedCharArray in lldb
As discussed in D65249, don't use AlignedCharArray or std::aligned_storage. Just use alignas(X) char Buf[Size];. This will allow me to remove AlignedCharArray entirely, and works on the current minimum version of Visual Studio.

llvm-svn: 367275
2019-07-29 23:17:08 +00:00
Jonas Devlieghere 63e5fb76ec [Logging] Replace Log::Printf with LLDB_LOG macro (NFC)
This patch replaces explicit calls to log::Printf with the new LLDB_LOGF
macro. The macro is similar to LLDB_LOG but supports printf-style format
strings, instead of formatv-style format strings.

So instead of writing:

  if (log)
    log->Printf("%s\n", str);

You'd write:

  LLDB_LOG(log, "%s\n", str);

This change was done mechanically with the command below. I replaced the
spurious if-checks with vim, since I know how to do multi-line
replacements with it.

  find . -type f -name '*.cpp' -exec \
  sed -i '' -E 's/log->Printf\(/LLDB_LOGF\(log, /g' "{}" +

Differential revision: https://reviews.llvm.org/D65128

llvm-svn: 366936
2019-07-24 17:56:10 +00:00
Jonas Devlieghere b2a9cf7764 [Logging] Replace LogIfAnyCategoriesSet with LLDB_LOG.
This patch removes any remaining instances of LogIfAnyCategoriesSet and
replaces them with the LLDB_LOG macro. This in turn made it possible to
make Log::VAPrintf and Log::VAError private.

llvm-svn: 366768
2019-07-22 23:48:01 +00:00
Joseph Tremoulet 3fd917d886 Support Linux signal return trampolines in frame initialization
Summary:
Add __kernel_rt_sigreturn to the list of trap handlers for Linux (it's
used as such on aarch64 at least), and __restore_rt as well (used on
x86_64).

Skip decrement-and-recompute for trap handlers in
InitializeNonZerothFrame, as signal dispatch may point the child frame's
return address to the start of the return trampoline.

Parse the 'S' flag for signal handlers from eh_frame augmentation, and
propagate it to the unwind plan.

Reviewers: labath, jankratochvil, compnerd, jfb, jasonmolenda

Reviewed By: jasonmolenda

Subscribers: clayborg, MaskRay, wuzish, nemanjai, kbarton, jrtc27, atanasyan, jsji, javed.absar, kristof.beyls, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D63667

llvm-svn: 366580
2019-07-19 14:05:55 +00:00
Pavel Labath 0f73709cb7 Remove null checks of results of new expressions
operator new doesn't return a null pointer, even if one turns off
exceptions (it calls std::terminate instead). Therefore, all of this is
dead code.

llvm-svn: 364744
2019-07-01 11:09:15 +00:00
Michal Gorny 8805829289 [lldb] [Process] Introduce common helpers to split/recombine YMM data
Introduce two common helpers to take care of splitting and recombining
YMM registers to/from XSAVE-like data.  Since FreeBSD, Linux and NetBSD
all use XSAVE-like data structures but with potentially different field
layouts, the function takes two pointers -- to XMM register and to YMM
high bits, and copies the data from/to YMMReg type.

While at it, remove support for big endian.  To mine and Pavel Labath's
combined knowledge, there is no such thing on x86.  Furthermore,
assuming that the YMM register data would be swapped for big endian
seems to be a weird assumption.

Differential Revision: https://reviews.llvm.org/D63610

llvm-svn: 364042
2019-06-21 13:19:34 +00:00
Alex Langford 86df61cc93 [Process] Remove unused field from HistoryThread
Summary:
These fields are unused and have been since their inception, from what
I can tell.

Reviewers: compnerd, JDevlieghere, davide, labath

Subscribers: kubamracek, lldb-commits

Differential Revision: https://reviews.llvm.org/D63357

llvm-svn: 363881
2019-06-19 21:33:44 +00:00
Antonio Afonso 943faef1fa Add support to read aux vector values
Summary:
This is the second patch to improve module loading in a series that started here (where I explain the motivation and solution): https://reviews.llvm.org/D62499

I need to read the aux vector to know where the r_debug map with the loaded libraries are.
The AuxVector class was made generic so it could be reused between the POSIX-DYLD plugin and NativeProcess*. The class itself ended up in the ProcessUtility plugin.

Reviewers: clayborg, xiaobai, labath, JDevlieghere

Reviewed By: clayborg, labath, JDevlieghere

Subscribers: emaste, JDevlieghere, mgorny, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D62500

llvm-svn: 363098
2019-06-11 20:16:13 +00:00
Pavel Labath 1a0312ca0b [FuncUnwinders] Use "symbol file" unwind plans for unwinding
Summary:
Previous patch (r360409) introduced the "symbol file unwind plan"
concept, but that plan wasn't used for unwinding yet. With this patch,
we start to consider the new plan as a possible strategy for both
synchronous and asynchronous unwinding. I also add a test that asserts
that unwinding via breakpad STACK CFI info works end-to-end.

Reviewers: jasonmolenda, clayborg

Subscribers: lldb-commits, amccarth, markmentovai

Differential Revision: https://reviews.llvm.org/D61853

llvm-svn: 361618
2019-05-24 09:54:39 +00:00
Konrad Kleine 248a13057a [lldb] NFC modernize codebase with modernize-use-nullptr
Summary:
NFC = [[ https://llvm.org/docs/Lexicon.html#nfc | Non functional change ]]

This commit is the result of modernizing the LLDB codebase by using
`nullptr` instread of `0` or `NULL`. See
https://clang.llvm.org/extra/clang-tidy/checks/modernize-use-nullptr.html
for more information.

This is the command I ran and I to fix and format the code base:

```
run-clang-tidy.py \
	-header-filter='.*' \
	-checks='-*,modernize-use-nullptr' \
	-fix ~/dev/llvm-project/lldb/.* \
	-format \
	-style LLVM \
	-p ~/llvm-builds/debug-ninja-gcc
```

NOTE: There were also changes to `llvm/utils/unittest` but I did not
include them because I felt that maybe this library shall be updated in
isolation somehow.

NOTE: I know this is a rather large commit but it is a nobrainer in most
parts.

Reviewers: martong, espindola, shafik, #lldb, JDevlieghere

Reviewed By: JDevlieghere

Subscribers: arsenm, jvesely, nhaehnle, hiraditya, JDevlieghere, teemperor, rnkovacs, emaste, kubamracek, nemanjai, ki.stfu, javed.absar, arichardson, kbarton, jrtc27, MaskRay, atanasyan, dexonsmith, arphaman, jfb, jsji, jdoerfert, lldb-commits, llvm-commits

Tags: #lldb, #llvm

Differential Revision: https://reviews.llvm.org/D61847

llvm-svn: 361484
2019-05-23 11:14:47 +00:00
Fangrui Song efe8e7e36d typedef enum -> enum
Reviewed By: labath

Differential Revision: https://reviews.llvm.org/D61883

llvm-svn: 360654
2019-05-14 08:55:50 +00:00
Fangrui Song 6c780b62f0 ARMDefines.h: fix -Wimplicit-fallthrough in -DLLVM_ENABLE_ASSERTIONS=OFF builds
Reviewed By: JDevlieghere

Differential Revision: https://reviews.llvm.org/D61844

llvm-svn: 360646
2019-05-14 04:09:52 +00:00
Fangrui Song b0e54cbcdf Fix file names in file headers. NFC
llvm-svn: 360554
2019-05-13 04:42:32 +00:00
Pavel Labath 95e72765c1 RegisterContextLLDB: Push CFA value on DWARF stack when evaluating register expressions
Summary:
This behavior is specified in the Section 6.4.2.3 (Register Rule
instructions) of the DWARF4 spec. We were not doing that, which meant
that any register rule which was relying on the cfa value being there
was not evaluated correctly (it was aborted due to "out of bounds"
access).

I'm not sure how come this wasn't noticed before, but I guess this has
something to do with the fact that dwarf unwind expressions are not used
very often, and when they are, the situation is so complicated that the
CFA is of no use. I noticed this when I started emitting dwarf
expressions for the unwind information present in breakpad symbol files.

Reviewers: jasonmolenda, clayborg

Subscribers: aprantl, lldb-commits

Differential Revision: https://reviews.llvm.org/D61018

llvm-svn: 360158
2019-05-07 15:27:35 +00:00
Jason Molenda c9f44cd4b6 RegisterContextLLDB::GetFullUnwindPlanForFrame has four verbose
logging messages that are written the same, making it difficult to
know for certain which code path was taken based on a logfile.  Add
some words to make each unique.

Right now the ordering for finding a FullUnwindPlan (ignoring
fallback unwind plan logic) is

1. If this is a _sigtramp like function, try eh_frame which is
   hand written on darwin systems to account for finding the
   saved register context correctly.

2. Ask the DynamicLoader if eh_frame should be preferred for
   this frame.  Some binaries on the system may have hand-written
   eh_frame and the DynamicLoader is the source for this.  (primarily
   this is for hand-written assembly in the objc runtime, and we tell
   lldb to trust that for functions in libobjc.dylib.)

3. if 0th frame, use GetUnwindPlanAtNonCallSite plan.

4. GetUnwindPlanAtCallSite {for 0th or any other}

5. GetUnwindPlanAtNonCallSite {now for non-0th frames, only if not from a compiler? hm.}

6. GetUnwindPlanArchitectureDefaultAtFunctionEntry if we're on the first instruction

7. Architectural default unwind plan ABI::CreateDefaultUnwindPlan


I'm moving #6 -- DefaultAtFunctionEntry -- up to between #3 and #4,
where we're already doing things specific to the zeroth frame.  If
we're on the zeroth frame and the GetUnwindPlanAtNonCallSite plan
has failed for some reason, and we're on the first instruction, we
should definitely use DefaultAtFunctionEntry instead of any other
unwind plan.  If we're trying to step out of some rando function
on the system that we couldn't assembly instruction inspect, this
is sufficient for us to step out of it.

llvm-svn: 359847
2019-05-02 23:49:56 +00:00
Pavel Labath 2359429168 FuncUnwinders: remove "current_offset" from function arguments
Summary:
This argument was added back in 2010 (r118882) to support the ability to unwind
from functions whose eh_frame entry does not cover the entire range of
the function.

However, due to the caching happening in FuncUnwinders, this solution is
very fragile. FuncUnwinders will cache the plan it got from eh_frame
regardless of the value of the current_offset, so our ability to unwind
from a given function depended what was the value of "current_offset" the
first time that this function was called.

Furthermore, since the "image show-unwind" command did not know what's
the right offset to pass, this created an unfortunate situation where
"image show-unwind" would show no valid plans for a function, even
though they were available and being used.

In this patch I implement the feature slightly differently. Instead of
giving just a base address to the eh_frame unwinder, I give it the
entire range we are interested in. Then, I change the unwinder to return
the first plan that covers (even partially) that range. This way even a
partial plan will be returned, regardless of the address in the function
where we are stopped at.

This solution is still not 100% correct, as it will not handle a
function which is covered by two independent fde entries. However, I
don't expect anybody will write this kind of functions, and this wasn't
handled by the previous implementation either. If this is ever needed in
the future. The eh_frame unwinder can be extended to return "composite"
unwind plans created by merging sevelar fde entries.

I also create a test which triggers this scenario. As doing this is
virtually impossible without hand-written assembly, the test only works
on x86 linux.

Reviewers: jasonmolenda, clayborg

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D60829

llvm-svn: 358964
2019-04-23 09:57:14 +00:00
Jonas Devlieghere 8b3af63b89 [NFC] Remove ASCII lines from comments
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
2019-04-10 20:48:55 +00:00
Adrian Prantl 4c03ea14f2 Unify random timeouts throughout LLDB and make them configurable.
Since these timeouts guard against catastrophic error in debugserver,
I also increased all of them to the maximum value among them.

The motivation for this test was the observation that an asanified
LLDB would often exhibit seemingly random test failures that could be
traced back to debugserver packets getting out of sync. With this path
applied I can no longer reproduce the one particular failure mode that
I was investigating.

rdar://problem/49441261

Differential Revision: https://reviews.llvm.org/D60340

llvm-svn: 357829
2019-04-05 22:43:42 +00:00
Pavel Labath cf6c19c2d3 Fix an out-of-bounds error in RegisterContextDarwin_arm64
Summary:
gcc diagnoses this as "array subscript 63 is above array bounds of
'RegisterContextDarwin_arm64::VReg [32]'".

The correct fix seems to be subtracting the fpu register base index, but
I have no way of verifying that this actually works.

Reviewers: jasonmolenda

Subscribers: javed.absar, kristof.beyls, lldb-commits

Differential Revision: https://reviews.llvm.org/D59495

llvm-svn: 357055
2019-03-27 09:39:46 +00:00
Adrian Prantl f05b42e960 Bring Doxygen comment syntax in sync with LLVM coding style.
This changes '@' prefix to '\'.

llvm-svn: 355841
2019-03-11 17:09:29 +00:00
Adrian Prantl 0e4c482124 Pass ConstString by value (NFC)
My apologies for the large patch. With the exception of ConstString.h
itself it was entirely produced by sed.

ConstString has exactly one const char * data member, so passing a
ConstString by reference is not any more efficient than copying it by
value. In both cases a single pointer is passed. But passing it by
value makes it harder to accidentally return the address of a local
object.

(This fixes rdar://problem/48640859 for the Apple folks)

Differential Revision: https://reviews.llvm.org/D59030

llvm-svn: 355553
2019-03-06 21:22:25 +00:00
Pavel Labath 4f85014dff Remove alignment from struct XSAVE altogether
I reduced the alignment of this struct in r342029 to avoid compiler
warnings about under-aligned allocations, but it turns out that this
still causes problems with some compilers (see r353778). As I hinted in
r342029, I don't believe any special aligment is necessary here (the
only reason for that would be if we used some aligned SSE instructions to
access this buffer, but I don't see any reason why we should do that),
so here I go all the way, and remove the alignment requirements (except
the ones naturally imposed by basic types) altogether.

llvm-svn: 354125
2019-02-15 12:20:23 +00:00