Commit Graph

61 Commits

Author SHA1 Message Date
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
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
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
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
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
2019-01-19 08:50:56 +00:00
Jonas Devlieghere a6682a413d Simplify Boolean expressions
This patch simplifies boolean expressions acorss LLDB. It was generated
using clang-tidy with the following command:

run-clang-tidy.py -checks='-*,readability-simplify-boolean-expr' -format -fix $PWD

Differential revision: https://reviews.llvm.org/D55584

llvm-svn: 349215
2018-12-15 00:15:33 +00:00
Jason Molenda a11b3fe26f Change the unwinder to not use a hard-coded limit on the
max number of stack frames to backtrace, make it a setting,
target.process.thread.max-backtrace-depth.
Add a test case for the setting.

<rdar://problem/28759559> 

llvm-svn: 343029
2018-09-25 21:01:54 +00:00
Adrian Prantl 05097246f3 Reflow paragraphs in comments.
This is intended as a clean up after the big clang-format commit
(r280751), which unfortunately resulted in many of the comment
paragraphs in LLDB being very hard to read.

FYI, the script I used was:

import textwrap
import commands
import os
import sys
import re
tmp = "%s.tmp"%sys.argv[1]
out = open(tmp, "w+")
with open(sys.argv[1], "r") as f:
  header = ""
  text = ""
  comment = re.compile(r'^( *//) ([^ ].*)$')
  special = re.compile(r'^((([A-Z]+[: ])|([0-9]+ )).*)|(.*;)$')
  for line in f:
      match = comment.match(line)
      if match and not special.match(match.group(2)):
          # skip intentionally short comments.
          if not text and len(match.group(2)) < 40:
              out.write(line)
              continue

          if text:
              text += " " + match.group(2)
          else:
              header = match.group(1)
              text = match.group(2)

          continue

      if text:
          filled = textwrap.wrap(text, width=(78-len(header)),
                                 break_long_words=False)
          for l in filled:
              out.write(header+" "+l+'\n')
              text = ""

      out.write(line)

os.rename(tmp, sys.argv[1])

Differential Revision: https://reviews.llvm.org/D46144

llvm-svn: 331197
2018-04-30 16:49:04 +00:00
Zachary Turner 6f9e690199 Move Log from Core -> Utility.
All references to Host and Core have been removed, so this
class can now safely be lowered into Utility.

Differential Revision: https://reviews.llvm.org/D30559

llvm-svn: 296909
2017-03-03 20:56:28 +00:00
Pavel Labath 766fd11597 Remove TimeValue from UnwindLLDB.cpp
Really NFC, as the code is #ifdefed out, but I did make sure it compiles if I enable it.

llvm-svn: 285797
2016-11-02 10:27:54 +00:00
Kate Stone b9c1b51e45 *** This commit represents a complete reformatting of the LLDB source code
*** 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
2016-09-06 20:57:50 +00:00
Jason Molenda 17b45390db Revert r273524, it may have been the cause of a linux testbot failure
for TestNamespaceLookup.py; didn't see anything obviously wrong so I'll
need to look at this more closely before re-committing.  (passed OK on
macOS ;)

llvm-svn: 273531
2016-06-23 04:24:16 +00:00
Jason Molenda cb6dae22e2 Do some minor renames of "Mac OS X" to "macOS".
There's uses of "macosx" that will be more tricky to
change, like in triples (e.g. "x86_64-apple-macosx10.11") - 
for now I'm just updating source comments and strings printed 
for humans.

llvm-svn: 273524
2016-06-23 01:18:16 +00:00
Abhishek Aggarwal be994649b4 Fix to solve Bug 23139 & Bug 23560
Summary:
 - Reason of both bugs:

   1. For the very first frame, Unwinder doesn't check the validity
      of Full UnwindPlan before creating StackFrame from it:

        When 'process launch' command is run after setting a breakpoint
        in inferior, the Unwinder runs and saves only Frame 0 (the frame
        in which breakpoint was set) in thread's StackFrameList i.e.
        m_curr_frames_sp. However, it doesn't check the validity of the
        Full UnwindPlan for this frame by unwinding 2 more frames further.

   2. Unwinder doesn't update the CFA value of Cursor when Full UnwindPlan
      fails and FallBack UnwindPlan succeeds in providing valid CFA values
      for frames:

        Sometimes during unwinding of stack frames, the Full UnwindPlan
        inside the RegisterContextLLDB object may fail to provide valid
        CFA values for these frames. Then the Fallback UnwindPlan is used
        to unwind the frames.

        If the Fallback UnwindPlan succeeds, then it provides a valid new
        CFA value. The RegisterContextLLDB::m_cfa field of Cursor object
        is updated during the Fallback UnwindPlan execution. However,
        UnwindLLDB misses the implementation to update the 'cfa' field
        of this Cursor with this valid new CFA value.

 - This patch fixes both these issues.

 - Remove XFAIL in test files corresponding to these 2 Bugs

Change-Id: I932ea407545ceee2d628f946ecc61a4806d4cc86
Signed-off-by: Abhishek Aggarwal <abhishek.a.aggarwal@intel.com>

Reviewers: jingham, lldb-commits, jasonmolenda

Subscribers: lldb-commits, ovyalov, tberghammer

Differential Revision: http://reviews.llvm.org/D14226

llvm-svn: 253026
2015-11-13 10:47:49 +00:00
Tamas Berghammer 8d53464472 Improve UnwindLLDB with better detection for unwinding failures
Previously we accepted a frame as correct result if the PC pointed
into an executable section of code. The isse with that approac is
that if we calculated PC correctly but messed up the value of CFA
then unwinding from the next fram will most likely fail.

With this change I modify the logic with keeping the requirement
for PC to point to an executable section and also check that we can
continue the unwind from the frame we calculated. If continuing from
the frame calculated with the primary unwind plan isn't working then
fall back to the fallback plan with the hope for a better frame (if
the fallback plan won't help then we acceot the frame from the
primary plan).

Differential revision: http://reviews.llvm.org/D10932

llvm-svn: 241434
2015-07-06 09:24:20 +00:00
Zachary Turner 32abc6edac Reduce header footprint of Target.h
This continues the effort to reduce header footprint and improve
build speed by removing clang and other unnecessary headers
from Target.h.  In one case, some headers were included solely
for the purpose of declaring a nested class in Target, which was
not needed by anybody outside the class.  In this case the
definition and implementation of the nested class were isolated
in the .cpp file so the header could be removed.

llvm-svn: 231107
2015-03-03 19:23:09 +00:00
Jason Molenda ce19fe3f38 Add a new 'eRegisterInLiveRegisterContext' RegisterLocation to track
a register value that is live in the stack frame 0 register context.

Fixes a problem where retrieving a register value on stack frame #n
would involved O(n!) stack frame checks.  This could be very slow on
a deep stack when retrieving register values that had not been
modified/saved by any of the stack frames.  Not common, but annoying
when it was hit.

<rdar://problem/19010211> 

llvm-svn: 223843
2014-12-09 22:28:10 +00:00
Jason Molenda cea6d634a5 When a RegisterContext produces an invalid CFA address, change
UnwindLLDB::AddOneMoreFrame to try the fallback unwind plan on
that same stack frame before it tries the fallback unwind plan
on the "next" or callee frame.

In RegisterContextLLDB::TryFallbackUnwindPlan, when we're
trying the fallback unwind plan to see if it is valid, make
sure we change all of the object ivars that might be used in
the process of fetching the CFA & caller's saved pc value 
and restore those if we decide not to use the fallback 
unwindplan.

<rdar://problem/19035079> 

llvm-svn: 222601
2014-11-22 01:52:03 +00:00
Jason Molenda 22975a28ac A pretty big overhaul of the TryFallbackUnwindPlan method in
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
2014-11-13 07:31:45 +00:00
Jason Molenda 4b00893243 Back out r221229 -- instead of trying to identify the end of the unwind,
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
2014-11-04 05:28:40 +00:00
Jason Molenda d98c3abf9f After we've completed a full backtrace, we'll have one frame which
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
2014-11-04 02:31:50 +00:00
Saleem Abdulrasool 3985c8c646 sanitise sign comparisons
This is a mechanical change addressing the various sign comparison warnings that
are identified by both clang and gcc.  This helps cleanup some of the warning
spew that occurs during builds.

llvm-svn: 205390
2014-04-02 03:51:35 +00:00
Jason Molenda 31d7ad4ecf Add a new idea of a "fallback" UnwindPlan to the RegisterContextLLDB
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
2014-02-21 05:20:25 +00:00
Jason Molenda a4bea72ee7 Add a new target setting, trap-handler-names, where a user can
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
2014-02-14 05:06:49 +00:00
Jason Molenda 6223db2778 The Platform base class now maintains a list of trap handlers
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
2014-02-13 07:11:08 +00:00
Jason Molenda 4b79247750 Don't enforce ABI stack alignment rules on the sigtramp frame --
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
2014-01-03 22:06:25 +00:00
Jason Molenda 3d21975a44 Partially revert a patch from Ashok Thirumurthi in r191430.
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
2013-12-20 01:05:11 +00:00
Jason Molenda b57e4a1bc6 Roll back the changes I made in r193907 which created a new Frame
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
2013-11-04 09:33:30 +00:00
Jason Molenda f23bf7432c Add a new base class, Frame. It is a pure virtual function which
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
2013-11-02 02:23:02 +00:00
Ashok Thirumurthi 8b5773053b Fix the partial backtrace in a recursive inferior compiled with -fomit-frame-pointer.
- Removes the block in UnwindLLDB::AddOneMoreFrame that tests for a bad stack setup,
since it is neither correct (tests the FP GPR), complete (doesn't consider multi-frame
cycles), nor reachable (the construction of RegisterContextLLDB will fail in the case 
where either of the two (why just two?) previous frames have the same canonical frame
address as the frame that we propose adding to the stack).

llvm-svn: 191430
2013-09-26 14:35:59 +00:00
Jason Molenda 23399d765c Change UnwindLLDB::SearchForSavedLocationForRegister so that it will allow for
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
2013-06-05 00:12:50 +00:00
Jason Molenda 9dbe9e630e Add a hard limit to how many frames lldb will unwind in a single
thread before UnwindLLDB::AddOneMoreFrame calls it quits.  We have
a couple of reports of unending backtraces in the field and we
haven't been able to collect any information about what kind of
backtrace is causing this.  We've found on Mac OS X that it's tricky
to get more than around 200k stack frames before a process exceeds
its stack space so we're starting with a hard limit of 300,000 frames.
<rdar://problem/13383069> 

llvm-svn: 180995
2013-05-03 04:48:41 +00:00
Greg Clayton 5160ce5c72 <rdar://problem/13521159>
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
2013-03-27 23:08:40 +00:00
Jason Molenda 4c781fd78a <rdar://problem/12350715>
Modify UnwindLLDB::SearchForSavedLocationForRegister so if the register
save locations for a register mid-stack is in another register (or in the
same register, indicating the reg wasn't modified in this frame), don't
return that as a found location.  Keep iterating down the array of frames
until a concrete location/value for the register is found, or until we
get to frame 0 where the reg value can be used as-is.

If lldb was trying to backtrace a program that blew out its stack via
recursion and the unwind instructions had some kind of 
this-reg-is-saved-in-that-reg instruction, lldb would revert to doing 
a recursive search for a concrete value and blow out its own stack.

llvm-svn: 172887
2013-01-19 03:53:42 +00:00
Daniel Malea d01b2953fa Resolve printf formatting warnings on Linux:
- use macros from inttypes.h for format strings instead of OS-specific types

Patch from Matt Kopec!

llvm-svn: 168945
2012-11-29 21:49:15 +00:00
Jason Molenda aff2a269e3 A change in how we search for saved register values unintentionally
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
2012-11-16 01:03:31 +00:00
Jason Molenda 60f0bd4944 Add a new capability to RegisterContextLLDB: To recognize when the
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
2012-10-26 06:08:58 +00:00
Jim Ingham 28eb57114d Bunch of cleanups for warnings found by the llvm static analyzer.
llvm-svn: 165808
2012-10-12 17:34:26 +00:00
Jim Ingham b0c72a5f58 Make the StackFrameList::GetFrameAtIndex only fetch as many stack frames as needed to
get the frame requested.
<rdar://problem/10943135>

llvm-svn: 151705
2012-02-29 03:40:22 +00:00
Greg Clayton e72dfb321c <rdar://problem/10103468>
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
2012-02-24 01:59:29 +00:00
Greg Clayton 1ac04c3088 Thread hardening part 3. Now lldb_private::Thread objects have std::weak_ptr
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
2012-02-21 00:09:25 +00:00
Greg Clayton e1cd1be6d6 Switching back to using std::tr1::shared_ptr. We originally switched away
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
2012-01-29 20:56:30 +00:00
Jason Molenda 707fec479c Restructure the relationship between UnwindLLDB and the
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
2011-11-01 03:21:25 +00:00
Jim Ingham 8f07716139 Lock the Unwinder before accessing it.
llvm-svn: 142632
2011-10-21 01:49:48 +00:00
Peter Collingbourne ba23ca085f Switch from USEC_PER_SEC/NSEC_PER_SEC/NSEC_PER_USEC to TimeValue constants
Fixes the Linux build.

llvm-svn: 133370
2011-06-18 23:52:14 +00:00
Greg Clayton 1cbc52cd64 Added some comments.
llvm-svn: 132066
2011-05-25 17:56:20 +00:00
Greg Clayton 9b72eb7101 ABI plug-ins must implement the following pure virtual functions:
virtual bool
ABI::StackUsesFrames () = 0;

Should return true if your ABI uses frames when doing stack backtraces. This
means a frame pointer is used that points to the previous stack frame in some
way or another.

virtual bool
ABI::CallFrameAddressIsValid (lldb::addr_t cfa) = 0;

Should take a look at a call frame address (CFA) which is just the stack
pointer value upon entry to a function. ABIs usually impose alignment
restrictions (4, 8 or 16 byte aligned), and zero is usually not allowed.
This function should return true if "cfa" is valid call frame address for
the ABI, and false otherwise. This is used by the generic stack frame unwinding
code to help determine when a stack ends.

virtual bool
ABI::CodeAddressIsValid (lldb::addr_t pc) = 0;    

Validates a possible PC value and returns true if an opcode can be at "pc".
Some ABIs or architectures have fixed width instructions and must be aligned
to a 2 or 4 byte boundary. "pc" can be an opcode or a callable address which
means the load address might be decorated with extra bits (such as bit zero
to indicate a thumb function call for ARM targets), so take this into account
when returning true or false. The address should also be validated to ensure
it is a valid address for the address size of the inferior process. 32 bit
targets should make sure the address is less than UINT32_MAX.

Modified UnwindLLDB to use the new ABI functions to help it properly terminate
stacks.


Modified the mach-o function that extracts dependent files to not resolve the
path as the paths inside a binary might not match those on the current
host system.

llvm-svn: 132021
2011-05-24 23:06:02 +00:00
Greg Clayton 31f1d2f535 Moved all code from ArchDefaultUnwindPlan and ArchVolatileRegs into their
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
2011-05-11 18:39:18 +00:00
Greg Clayton dc5eb693bd Put plug-ins into the correct directories as they were incorrectly located
in a Utility directory.

llvm-svn: 130135
2011-04-25 18:36:36 +00:00
Greg Clayton e576ab2996 All UnwindPlan objects are now passed around as shared pointers.
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
2011-02-15 00:19:15 +00:00
Greg Clayton fc75303acb Avoid infinite loops in stack backtraces and renamed:
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
2011-01-17 21:03:33 +00:00