Commit Graph

23 Commits

Author SHA1 Message Date
Tamas Berghammer 648f3c7efa Add support for .ARM.exidx unwind information
.ARM.exidx/.ARM.extab sections contain unwind information used on ARM
architecture from unwinding from an exception.

Differential revision: http://reviews.llvm.org/D13245

llvm-svn: 248903
2015-09-30 13:50:14 +00:00
Jason Molenda a18f7071c2 A messy bit of cleanup: Move towards more descriptive names
for eh_frame and stabs register numberings.  This is not
complete but it's a step in the right direction.  It's almost
entirely mechanical.

lldb informally uses "gcc register numbering" to mean eh_frame.
Why?  Probably because there's a notorious bug with gcc on i386
darwin where the register numbers in eh_frame were incorrect.
In all other cases, eh_frame register numbering is identical to
dwarf.

lldb informally uses "gdb register numbering" to mean stabs.
There are no official definitions of stabs register numbers
for different architectures, so the implementations of gdb
and gcc are the de facto reference source.

There were some incorrect uses of these register number types
in lldb already.  I fixed the ones that I saw as I made
this change.

This commit changes all references to "gcc" and "gdb" register
numbers in lldb to "eh_frame" and "stabs" to make it clear 
what is actually being represented.

lldb cannot parse the stabs debug format, and given that no
one is using stabs any more, it is unlikely that it ever will.
A more comprehensive cleanup would remove the stabs register
numbers altogether - it's unnecessary cruft / complication to
all of our register structures.

In ProcessGDBRemote, when we get register definitions from
the gdb-remote stub, we expect to see "gcc:" (qRegisterInfo)
or "gcc_regnum" (qXfer:features:read: packet to get xml payload).
This patch changes ProcessGDBRemote to also accept "ehframe:"
and "ehframe_regnum" from these remotes.

I did not change GDBRemoteCommunicationServerLLGS or debugserver
to send these new packets.  I don't know what kind of interoperability
constraints we might be working under.  At some point in the future
we should transition to using the more descriptive names.

Throughout lldb we're still using enum names like "gcc_r0" and "gdb_r0",
for eh_frame and stabs register numberings.  These should be cleaned
up eventually too.

The sources link cleanly on macosx native with xcode build.  I
don't think we'll see problems on other platforms but please let
me know if I broke anyone.

llvm-svn: 245141
2015-08-15 01:21:01 +00:00
Jason Molenda e589e7e336 The lldb unwinder can now use the unwind information from the compact-unwind
section for x86_64 and i386 targets on Darwin systems.  Currently only the
compact unwind encoding for normal frame-using functions is supported but it
will be easy handle frameless functions when I have a bit more free time to
test it.  The LSDA and personality routines for functions are also retrieved
correctly for functions from the compact unwind section.

This new code is very fresh -- it passes the lldb testsuite and I've done
by-hand inspection of many functions and am getting correct behavior for all
of them.  There may need to be some bug fixing over the next couple weeks as
I exercise and test it further.  But I think it's fine right now so I'm
committing it.

<rdar://problem/13220837> 

llvm-svn: 223625
2014-12-08 03:09:00 +00:00
Jason Molenda 5cba569c4b Add a lock in the UnwindTable class so two Targets won't try
to modify the same UnwindTable object simultaneously.  Fix
HistoryThread and HistoryUnwind's mutex lock acqusition to
retain the lock for the duration of the operation instead of
releasing the temporary immediately.
<rdar://problem/17055023>

llvm-svn: 211241
2014-06-18 23:32:53 +00:00
Jason Molenda ab35aa92da Instead of having an UnwindTable own a single assembly profiler,
and sharing it with all of its FuncUnwinders, have each FuncUnwinder
create an AssemblyProfiler on demand as needed.  I was worried that
the cost of creating the llvm disassemblers would be high for this
approach but it's not supposed to be an expensive operation, and it
means we don't need to add locks around this section of code.
<rdar://problem/16992332> 

llvm-svn: 209493
2014-05-23 01:48:10 +00:00
Jason Molenda 23a285d2d6 Revert r209488; Greg suggests a different approach.
llvm-svn: 209492
2014-05-23 01:42:56 +00:00
Jason Molenda f5e8a14bd6 The UnwindTable (one per module) used to hand out shared pointers
to its unwind assembly profiler to all of the FuncUnwinders (one
per symbol) under it.  If lldb is running multiple targets, you
could get two different FuncUnwinders in the same Module trying
to use the same llvm disassembler simultaneously and that may be
a re-entrancy problem.  

Instead, the UnwindTable has the unwind assembly profiler and when
the FuncUnwinders want to use it, they get exclusive access to
the assembly profiler until they're done using it.
<rdar://problem/16992332> 

llvm-svn: 209488
2014-05-23 00:08:09 +00:00
Ed Maste d4612ad0f3 Switch NULL to C++11 nullptr in source/Symbol and source/Utility
Patch by Robert Matusewicz

llvm-svn: 206713
2014-04-20 13:17:36 +00:00
Michael Sartain 762df1f139 Merge RegisterContextPOSIX_x86_64 and RegisterContextPOSIX_i386 into RegisterContextPOSIX_x86
llvm-svn: 192332
2013-10-10 00:16:10 +00:00
Greg Clayton b5ad4ec7a3 Cleanup logging to use the new "std::string FileSpec::GetPath()" function. Also added a similar function for modules:
std::string
Module::GetSpecificationDescription () const;

This returns the module as "/usr/lib/libfoo.dylib" for normal files (calls "std::string FileSpec::GetPath()" on m_file) but it also might include the object name in case the module is for a .o file in a BSD archive ("/usr/lib/libfoo.a(bar.o)"). Cleaned up necessary logging code to use it.

llvm-svn: 180717
2013-04-29 17:25:54 +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 380241a81f Add a new 'target modules show-unwind' command to show the different
UnwindPlans for a function.  This specifically does not use any
previously-generated UnwindPlans so if any logging is performed
while creating the UnwindPlans, it will be repeated.  This is
useful for when an lldb stack trace is not correct and you want
to gather diagnostic information from the user -- they can do 
log enable -v lldb unwind, image show-unwind of the function, and
you'll get the full logging as the UnwindPlans are recreated.

llvm-svn: 160095
2012-07-12 00:20:07 +00:00
Greg Clayton 9c76611055 Added the ability to disassembly "count" instructions given a SBAddress.
This was done in SBTarget:

lldb::SBInstructionList
lldb::SBTarget::ReadInstructions (lldb::SBAddress base_addr, uint32_t count);

Also cleaned up a few files in the LLDB.framework settings.

llvm-svn: 152152
2012-03-06 22:24:44 +00:00
Greg Clayton 7be2542fc9 Renamed UnwindAssemblyProfiler to UnwindAssembly along with its source files.
llvm-svn: 130156
2011-04-25 21:14:26 +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 7e14f91dbd Fixed the SymbolContext::DumpStopContext() to correctly indent and dump
inline contexts when the deepest most block is not inlined.

Added source path remappings to the lldb_private::Target class that allow it
to remap paths found in debug info so we can find source files that are elsewhere
on the current system.

Fixed disassembly by function name to disassemble inline functions that are
inside other functions much better and to show enough context before the
disassembly output so you can tell where things came from.

Added the ability to get more than one address range from a SymbolContext 
class for the case where a block or function has discontiguous address ranges.

llvm-svn: 130044
2011-04-23 02:04:55 +00:00
Stephen Wilson 71c21d18c3 Order of initialization lists.
This patch fixes all of the warnings due to unordered initialization lists.

Patch by Marco Minutoli.

llvm-svn: 129290
2011-04-11 19:41:40 +00:00
Greg Clayton 514487e806 Made lldb_private::ArchSpec contain much more than just an architecture. It
now, in addition to cpu type/subtype and architecture flavor, contains:
- byte order (big endian, little endian)
- address size in bytes
- llvm::Triple for true target triple support and for more powerful plug-in
  selection.

llvm-svn: 125602
2011-02-15 21:59:32 +00:00
Greg Clayton b0848c5d91 Fixed issues with the unwinding code where the collection of FuncUnwinders
was being searched and sorted using a shared pointer as the value which means
the pointer value was what was being searched for. This means that anytime
you did a stack backtrace, the collection of FuncUnwinders doubled and then
the array or shared pointer got sorted (by pointer value), so you had an ever
increasing collection of shared pointer where a match was never found. This
means we had a ton of duplicates in this table and would cause issues after
one had been debugging for a long time.

llvm-svn: 123045
2011-01-08 00:05:12 +00:00
Jason Molenda 45b4924550 Fix thinko in UnwindTable.cpp where it wouldn't provde a
FuncUnwinders object if the eh_frame section was missing
from an objfile.  Worked fine on x86_64 but on i386 where
eh_frame is unusual, that resulted in the arch default 
UnwindPlan being used all the time instead of picking up
an assembly profile based unwindplan.

llvm-svn: 118467
2010-11-09 01:21:22 +00:00
Jason Molenda 5976200d43 Handle the case where no eh_frame section is present.
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
2010-11-04 00:53:20 +00:00
Greg Clayton a51ed9bb49 Added motheds to C++ classes as we parse them to keep clang happy.
llvm-svn: 114616
2010-09-23 01:09:21 +00:00
Jason Molenda fbcb7f2c4e The first part of an lldb native stack unwinder.
The Unwind and RegisterContext subclasses still need
to be finished; none of this code is used by lldb at
this point (unless you call into it by hand).

The ObjectFile class now has an UnwindTable object.

The UnwindTable object has a series of FuncUnwinders
objects (Function Unwinders) -- one for each function
in that ObjectFile we've backtraced through during this
debug session.

The FuncUnwinders object has a few different UnwindPlans.
UnwindPlans are a generic way of describing how to find
the canonical address of a given function's stack frame
(the CFA idea from DWARF/eh_frame) and how to restore the
caller frame's register values, if they have been saved
by this function.

UnwindPlans are created from different sources.  One source is the
eh_frame exception handling information generated by the compiler
for unwinding an exception throw.  Another source is an assembly
language inspection class (UnwindAssemblyProfiler, uses the Plugin
architecture) which looks at the instructions in the funciton
prologue and describes the stack movements/register saves that are
done.

Two additional types of UnwindPlans that are worth noting are
the "fast" stack UnwindPlan which is useful for making a first
pass over a thread's stack, determining how many stack frames there
are and retrieving the pc and CFA values for each frame (enough
to create StackFrameIDs).  Only a minimal set of registers is
recovered during a fast stack walk.  

The final UnwindPlan is an architectural default unwind plan.
These are provided by the ArchDefaultUnwindPlan class (which uses
the plugin architecture).  When no symbol/function address range can
be found for a given pc value -- when we have no eh_frame information
and when we don't have a start address so we can't examine the assembly
language instrucitons -- we have to make a best guess about how to 
unwind.  That's when we use the architectural default UnwindPlan.
On x86_64, this would be to assume that rbp is used as a stack pointer
and we can use that to find the caller's frame pointer and pc value.
It's a last-ditch best guess about how to unwind out of a frame.

There are heuristics about when to use one UnwindPlan versues the other --
this will all happen in the still-begin-written UnwindLLDB subclass of
Unwind which runs the UnwindPlans.

llvm-svn: 113581
2010-09-10 07:49:16 +00:00