This is a large API change that removes the two functions from
StreamString that return a std::string& and a const std::string&,
and instead provide one function which returns a StringRef.
Direct access to the underlying buffer violates the concept of
a "stream" which is intended to provide forward only access,
and makes porting to llvm::raw_ostream more difficult in the
future.
Differential Revision: https://reviews.llvm.org/D26698
llvm-svn: 287152
plan generator.
Fix a small bug in EmulateInstructionARM64::GetFramePointerRegister
which was returning the stack pointer reg instead of fp, prevented
the unwinder from recognizing the switch to using the fp in a
function. (<rdar://problem/28663117>)
Add a new eContextRestoreStackPointer context hint so that the arm64
emulator can flag when the frame pointer value is copied back in to
the stack pointer and that should be used to compute the canonical
frame address again in an epilogue sequence. (<rdar://problem/28704862>)
Small changes to UnwindAssemblyInstEmulation to have a method we can
call without a live process/thread/etc for unit tests.
<rdar://problem/28663117>
<rdar://problem/28704862>
<rdar://problem/28509178>
llvm-svn: 283847
unittests. If I have time, I'd like to see if I can write some
tests of the eh_frame augmentation which is a wholly separate code
path (it seems like maybe it should be rolled into the main instruction
scanning codepath, to be honest, and operate on the generated
UnwindPlan instead of bothering with raw instructions at all).
Outside the eh_frame augmentation, I'm comfortable that this unwind
generator is being tested well now.
llvm-svn: 283186
'push 0x20(%esp)' which clang can generate when emitting
-fomit-frame-pointer code for 32-bit.
Add a unit test program which includes this instruction.
Also fix a bug in the refactoring/rewrite of the x86 assembly
instruction profiler where I'd hard coded it as a 64-bit disassembler
instead of using the ArchSpec to pick a 32-bit or 64-bit disassembler
from llvm. When the disassembler would hit an instruction
that is invalid in 64-bit mode, it would stop disassembling the function.
This likely led to the TestSBData testsuite failure on linux with 32-bit
i386 and gcc-4.9; I'll test that in a bit.
The newly added unit test program is 32-bit i386 code and it includes
an instruction which is invalid in 64-bit mode so it will catch this.
<rdar://problem/28557876>
llvm-svn: 282991
a linux bot test failure. That one is fixed; hopefully there won't
be any others turned up this time.
The eh_frame augmentation code wasn't working right after the
reorg/rewrite of the classes. It works correctly now for the one
test that was failing - but we'll see what the test bots come up
with.
<rdar://problem/28509178>
llvm-svn: 282659
A testbot found a regression introduced in the testsuite with
the changes in r282565 on Ubuntu (TestStepNoDebug.ReturnValueTestCase).
I'll get this set up on an ubuntu box and figure out what is happening
there -- likely a problem with the eh_frame augmentation, which isn't
used on macosx.
llvm-svn: 282566
x86AssemblyInspectionEngine and the current UnwindAssembly_x86 to
allow for the core engine to be exercised by unit tests.
The UnwindAssembly_x86 class will have access to Targets, Processes,
Threads, RegisterContexts -- it will be working in the full lldb
environment.
x86AssemblyInspectionEngine is layered away from all of that, it is
given some register definitions and a bag of bytes to profile.
I wrote an initial unittest for a do-nothing simple x86_64/i386
function to start with. I'll be adding more.
The x86 assembly unwinder was added to lldb early in its bringup;
I made some modernization changes as I was refactoring the code
to make it more consistent with how we write lldb today.
I also added RegisterContextMinidump_x86_64.cpp to the xcode project
file so I can run the unittests from that.
The testsuite passes with this change, but there was quite a bit of
code change by the refactoring and it's possible there are some
issues. I'll be testing this more in the coming days, but it looks
like it is behaving correctly as far as I can tell with automated
testing.
<rdar://problem/28509178>
llvm-svn: 282565
*** 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
This change is improving the instruction emulation based unwinding to
handle when the frame pointer is adjusted (increment/decrement) after
it has been initialized. The situation can occur in the prologue of
some function where FP is adjusted before it is copied back to SP.
Example code (thumb, generated by gcc 4.8):
< +0>: push {r4, r7, lr}
< +2>: sub sp, #0x14
< +4>: add r7, sp, #0x0
...
<+50>: adds r7, #0x14 ; The CL fixes the handling of this instruction
<+52>: mov sp, r7 ; Previously unwinding from here was broken
<+54>: pop {r4, r7, pc}
Differential revision: http://reviews.llvm.org/D17295
llvm-svn: 261318
The IT instruction can specify condition code for up to 4 consecutive
instruction and it is used quite often by clang in epilogues causing
an issue when trying to unwind from locations covered by the IT
instruction and for locatins inmediately after the IT instruction.
Changes made to fix it:
* Introduce the concept of conditional instruction block what is a list
of consecutive instructions with the same condition. We update the
unwind information during the conditional instruction block and when
we reach the end of it (first instruction with a differemt condition)
then we restore the unwind information we had before the condition.
* Fix a bug in the ARM instruction emulator where neither PC nor the
ITSTATE was advanced when we reached an instruction what we can't
decode.
After the change we have no regression on android-arm running the
regular test suit and TestStandardUnwind also passes when running it
with clang as the compiler (previously it failed on an IT instruction).
Differential revision: http://reviews.llvm.org/D16814
llvm-svn: 260368
Summary:
This doesn't exist in other LLVM projects any longer and doesn't
do anything.
Reviewers: chaoren, labath
Subscribers: emaste, tberghammer, lldb-commits, danalbert
Differential Revision: http://reviews.llvm.org/D12586
llvm-svn: 246749
Change the way EmulateInstruction::eContextPopRegisterOffStack handled
in UnwindAssemblyInstEmulation::WriteRegister to accomodate for
additional cases when eContextPopRegisterOffStack (pop PC/FLAGS).
llvm-svn: 245690
On ARM there is no difference petween a pop and a load instruction so
a register can be loaded multiple times during the function. Add check
to threat the load as a restore only if it do the restore from the
same location where the register was saved.
Differential revision: http://reviews.llvm.org/D11947
llvm-svn: 245546
Don't chane the CFI information when a conditional instruction
is emulated (eg.: popeq {r0, pc}) because the CFI for the next
instruction should be the same as the CFI for the current instruction.
Differential revision: http://reviews.llvm.org/D11258
llvm-svn: 242519
Summary: This aligns the library names used by the Makefile build to be the same as those create by the CMake build to make switching between the two easier. The only major difficulty was lldbHost which was one library in the CMake system and several in the Makefile system. Most of the other changes are trivial renames.
Reviewers: labath
Subscribers: emaste, tberghammer, lldb-commits
Differential Revision: http://reviews.llvm.org/D11154
llvm-svn: 242196
These instructions confusing the unwind code because in case of a
push it assumes that the original valu of a register is pushed to
the stack what is not neccessarily true in case of SP. The same is
true for the pop (in the opposite way).
Differential revision: http://reviews.llvm.org/D10806
llvm-svn: 241051
The emulation of the branches are required by the new stack
unwinding logic to reinstantiate the prologue at the right place.
Differential revision: http://reviews.llvm.org/D10702
llvm-svn: 240769
* Add and fix the emulation of several instruction.
* Disable frame pointer usage on Android.
* Specify return address register for the unwind plan instead of explict
tracking the value of RA.
* Replace prologue detection heuristics (unreliable in several cases)
with a logic to follow the branch instructions and restore the CFI
value based on them. The target address for a branch should have the
same CFI as the source address (if they are in the same function).
* Handle symbols in ELF files where the symbol size is not specified
with calcualting their size based on the next symbol (already done
in MachO files).
* Fix architecture in FuncUnwinders with filling up the inforamtion
missing from the object file with the architecture of the target.
* Add code to read register wehn the value is set to "IsSame" as it
meanse the value of a register in the parent frame is the same as the
value in the current frame.
Differential revision: http://reviews.llvm.org/D10447
llvm-svn: 240533
Gcc for android use the leal instruction to substract from the stack
pointer in the prologue of a function call. This patch add basic support
for evaluating this instruction to support stack unwinding on
android-x86.
Differential revision: http://reviews.llvm.org/D8583
llvm-svn: 233178
Summary:
This is initial implementation of assembly profiler which only scans prologue/epilogue assembly instructions to create CFI instructions.
Reviewers: clayborg, jasonmolenda
Differential Revision: http://reviews.llvm.org/D7696
llvm-svn: 232619
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
Summary:
This change refactors UnwindPlan::Row to be able to store the fact that the CFA is value is set
by evaluating a dwarf expression (DW_CFA_def_cfa_expression). This is achieved by creating a new
class CFAValue and moving all CFA setting/getting code there. Note that code using the new
CFAValue::isDWARFExpression is not yet present and will be added in a follow-up patch. Therefore,
this patch should not change the functionality in any way.
Test Plan: Ran tests on Mac and Linux. No regressions detected.
Reviewers: jasonmolenda, clayborg
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D7755
llvm-svn: 230210
changing it was in r219544 - after living on that for a few
months, I wanted to take another crack at this.
The disassembly-format setting still exists and the old format
can be user specified with a setting like
${current-pc-arrow}${addr-file-or-load}{ <${function.name-without-args}${function.concrete-only-addr-offset-no-padding}>}:
This patch was discussed in http://reviews.llvm.org/D7578
<rdar://problem/19726421>
llvm-svn: 229186
signed and unsigned types in comparisons.
For the text offset, use the addr_t type that is used elsewhere to get
these kinds of offsets, and which it is being compared against. This
seems to make things more consistent.
For the other, the numbers are clearly small and uninteresting, so just
cast them to the most boring 'int' type.
llvm-svn: 229085
Why? Debugger::FormatPrompt() would run through the format prompt every time and parse it and emit it piece by piece. It also did formatting differently depending on which key/value pair it was parsing.
The new code improves on this with the following features:
1 - Allow format strings to be parsed into a FormatEntity::Entry which can contain multiple child FormatEntity::Entry objects. This FormatEntity::Entry is a parsed version of what was previously always done in Debugger::FormatPrompt() so it is more efficient to emit formatted strings using the new parsed FormatEntity::Entry.
2 - Allows errors in format strings to be shown immediately when setting the settings (frame-format, thread-format, disassembly-format
3 - Allows auto completion by implementing a new OptionValueFormatEntity and switching frame-format, thread-format, and disassembly-format settings over to using it.
4 - The FormatEntity::Entry for each of the frame-format, thread-format, disassembly-format settings only replaces the old one if the format parses correctly
5 - Combines all consecutive string values together for efficient output. This means all "${ansi.*}" keys and all desensitized characters like "\n" "\t" "\0721" "\x23" will get combined with their previous strings
6 - ${*.script:} (like "${var.script:mymodule.my_var_function}") have all been switched over to use ${script.*:} "${script.var:mymodule.my_var_function}") to make the format easier to parse as I don't believe anyone was using these format string power user features.
7 - All key values pairs are defined in simple C arrays of entries so it is much easier to add new entries.
These changes pave the way for subsequent modifications where we can modify formats to do more (like control the width of value strings can do more and add more functionality more easily like string formatting to control the width, printf formats and more).
llvm-svn: 228207
saved/restored across a mid-function epilogue. We ignore
repeated push/pops of a register so once we saw one 'pop %rbp',
we'd ignore it the second time we saw it.
<rdar://problem/19417410>
llvm-svn: 225853
it will do the right thing on x86 routines with a mid-function
epilogue sequence (where the unwind rules need to be reinstalled
after the epilogue has completed).
<rdar://problem/19417410>
llvm-svn: 225773
which will verify if the eh_frame instructions include details about
the prologue or not. Both clang and gcc include prologue instructions
but there's no requirement for them to do so -- and I'm sure we'll
have to interoperate with a compiler that doesn't generate prologue
info at some point.
I don't have any compilers that omit the prologue instructions so the
testing was of the "makre sure augmented unwind info is still created".
With an eh_frame without prologue, this code should reject the
augmentation scheme altogether and we should fall back to using assembly
instruction profiling.
llvm-svn: 225771
step through the complete function looking for any epilogue
instructions. If we find an epilogue sequence, re-instate
the correct unwind instructions if there is more code past
that epilogue -- this will correctly handle an x86 function
with multiple epilogues in it.
NB there is still a bug with the "eh_frame augmented"
UnwindPlans and mid-function epilogues. Looking at that next.
<rdar://problem/18863406>
llvm-svn: 225770
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
which registers have been spilled (saved to the stack) - and
if we see that same register being saved to the stack again,
don't record that, it's something specific to this stack frame.
I found a code sequence for i386 where clang did a push %esi
and then later in the function it did movl %esi, -0x7c(%ebp)
and that second save of a scratch value overrode the original
push location.
<rdar://problem/19171178>
llvm-svn: 225431
Most of the changes are to the FuncUnwinders class -- as we've added
more types of unwind information, the way this class was written was
making it a mess to maintain. Instead of trying to keep one
"non-call site" unwind plan and one "call site" unwind plan, track
all the different types of unwind plans we can possibly retrieve for
each function and have the call-site/non-call-site accessor methods
retrieve those.
Add a real "fast unwind plan" for x86_64 / i386 -- when doing an
unwind through a function, this only has to read the first 4 bytes
to tell if the function has a standard prologue sequence. If so,
we can use the architecture default unwind plan to backtrace
through this function. If we try to retrieve the save location for
other registers later on, a real unwind plan will be used. This
one is just for doing fast backtraces.
Change the compact unwind plan importer to fill in the valid address
range it is valid for.
Compact unwind, in theory, may have multiple entries for a single
function. The FuncUnwinders rewrite includes the start of supporting
this correctly. In practice compact unwind encodings are used for
the entire range of the function today -- in fact, sometimes the same
encoding is used for multiple functions that have the same unwind
rules. But I want to handle a single function that has multiple
different compact unwind UnwindPlans eventually.
llvm-svn: 224689
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
MSVC warns that not all control paths return a value when a switch
doesn't have a default case handler. Changed explicit value checks
to a default check.
Also, it caught a case where bitwise AND was being used instead of
logical AND. I'm not sure what this fixes, but presumably it is
not covered by any kind of test case.
llvm-svn: 221636
a nop). Fixes an instruction stepping problem when trying to step
over the final instructions of an epilogue.
<rdar://problem/18068877>
llvm-svn: 221241
output style can be customized. Change the built-in default to be
more similar to gdb's disassembly formatting.
The disassembly-format for a gdb-like output is
${addr-file-or-load} <${function.name-without-args}${function.concrete-only-addr-offset-no-padding}>:
The disassembly-format for the lldb style output is
{${function.initial-function}{${module.file.basename}`}{${function.name-without-args}}:\n}{${function.changed}\n{${module.file.basename}`}{${function.name-without-args}}:\n}{${current-pc-arrow} }{${addr-file-or-load}}:
The two backticks in the lldb style formatter triggers the sub-expression evaluation in
CommandInterpreter::PreprocessCommand() so you can't use that one as-is ... changing to
use ' characters instead of ` would work around that.
<rdar://problem/9885398>
llvm-svn: 219544
I wrote this originally as a part of an unwind library that was using
a different coding convention and some of that old style remained after
its integration into lldb.
llvm-svn: 216419
We decided to use assmbly profiler instead of eh_frame for frame 0 because for compiler generated code, eh_frame is usually synchronous(a.k.a. only valid at call site); and we have no way to tell if it's asynchronous or not.
But for x86 & x86_64 compiler generated code:
1. clang & GCC describes all prologue instructions in eh_frame;
2. mid-function stack pointer altering instructions can be easily detected.
So we can grab eh_frame, and use assembly profiler to augment it into asynchronous unwind table.
This change also benefits hand-written assembly; eh_frame for hand-written assembly is often asynchronous,so we have a much better chance to successfully unwind through them.
Change by Tong Shen.
llvm-svn: 216406
to recognize an epilogue that ends with a jmp to
objc_retainAutoreleaseReturnValue instead of a ret instruction.
<rdar://problem/17889928>
llvm-svn: 214783
This change has the practical effect of fixing some backtrace
scenarios that would fail with inferiors running on the Android Art
host-side JVM under Linux x86_64 on Ubuntu 14.04.
See this lldb-commits thread for more details:
http://lists.cs.uiuc.edu/pipermail/lldb-commits/Week-of-Mon-20140721/011988.html
Change by Tong Shen.
Reviewed by Jason Molenda.
Tested:
Ubuntu 14.04 x86_64, clang-3.5-built lldb.
MacOSX 10.10 Preview 4, Xcode 6 Beta 4-built lldb.
llvm-svn: 213914
Zachary Turner