Summary:
The AST contexts are not needed in the server components, and the clang context in particular
pulls in large parts of clang into the binary. Simply removing these two calls reduces the
lldb-server size by about 50%--80%, depending on the architecture and build type.
This should not impact the client parts as the same calls are already present in
SystemInitializerFull.
Reviewers: tberghammer, clayborg
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D20236
llvm-svn: 269416
Patch by Nitesh Jain.
Summary: These patch will set clang::TargetOptions::ABI and accordingly code will be generated for MIPS target.
Reviewers: ovyalov, clayborg
Subscribers: lldb-commits, mohit.bhakkad, sagar, jaydeep, bhushan
Differential: D18638
llvm-svn: 269407
The main issues were:
- Listeners recently were converted over to used by getting a shared pointer to a listener. And when they listened to broadcasters they would get a strong reference added to them meaning the listeners would never go away. This caused memory usage to increase and would cause performance issue if many steps were done.
- The lldb_private::Process private state thread had an issue where if a "stop" contol signal was attempted to be sent to that thread, it could end up not responding in 2 seconds and end up getting cancelled which might cause us to cancel a thread that had a mutex locked and it would deadlock the test.
This change makes broadcasters hold onto weak references to listeners. It also fixes some bad threading code that had races inside of it by making the m_events_mutex be non-recursive and getting rid of fragile use of a Predicate<bool> to say that new events are available, and replacing it with using the m_events_mutex with a new m_events_condition to control access to the events in a safer way.
The private state thread now uses a safer way to communicate that the control event has been received by the private state thread: it makes a EventDataReceipt instance that it attaches to the event that sends the control to the private state thread and used this to synchronize the fact that the private state thread has received the event instead of using a Predicate<bool> to convey the info. When the signal event is received, it will pull the event off of the queue in the private state thread and cause the EventData::DoOnRemoval() to be called, which will signal that the event has been received. This cleans up the signal delivery notification so it doesn't rely on a member variable of the process class to convey the info.
std::shared_ptr<EventDataReceipt> event_receipt_sp(new EventDataReceipt());
m_private_state_control_broadcaster.BroadcastEvent(signal, event_receipt_sp);
<rdar://problem/26256353> Listeners are being kept around longer than they should be due to recent changs
<rdar://problem/26256258> Private process state thread can be cancelled and cause deadlocks in test suite
llvm-svn: 269377
This allows expressions such as 'i == 1 || i == 2` to be executed using the IR interpreter, instead of relying on JIT code injection (which may not be available on some platforms).
Patch by cameron314
Differential Revision: http://reviews.llvm.org/D19124
llvm-svn: 269340
Summary:
MonitorDebugServerProcess went to a lot of effort to make sure its asynchronous invocation does
not cause any mischief, but it was still not race-free. Specifically, in a quick stop-restart
sequence (like the one in TestAddressBreakpoints) the copying of the process shared pointer via
target_sp->GetProcessSP() was racing with the resetting of the pointer in DeleteCurrentProcess,
as they were both accessing the same shared_ptr object.
To avoid this, I simply pass in a weak_ptr to the process when the callback is created. Locking
this pointer is race-free as they are two separate object even though they point to the same
process instance. This also removes the need for the complicated tap-dance around retrieving the
process pointer.
Reviewers: clayborg
Subscribers: tberghammer, lldb-commits
Differential Revision: http://reviews.llvm.org/D20107
llvm-svn: 269281
Summary:
The "file" variable in a LineEntry was mapped using target.source-map, except when stepping through inlined code. This patch adds a new variable to LineEntry, "original_file", that contains the original file from the debug info. "file" will continue to (possibly) be mapped.
Some code has been changed to use "original_file". This is code dealing with symbols. Code dealing with source files will still use "file". Reviewers, please confirm that these particular changes are correct.
Tests run on Ubuntu 12.04 show no regression.
Reviewers: clayborg, jingham
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D20135
llvm-svn: 269250
Summary:
This replaces the C-style "void *" baton of the child process monitoring functions with a more
C++-like API taking a std::function. The motivation for this was that it was very difficult to
handle the ownership of the object passed into the callback function -- each caller ended up
implementing his own way of doing it, some doing it better than others. With the new API, one can
just pass a smart pointer into the callback and all of the lifetime management will be handled
automatically.
This has enabled me to simplify the rather complicated handshake in Host::RunShellCommand. I have
left handling of MonitorDebugServerProcess (my original motivation for this change) to a separate
commit to reduce the scope of this change.
Reviewers: clayborg, zturner, emaste, krytarowski
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D20106
llvm-svn: 269205
Patch by Nitesh Jain.
Summary: The ArchSpec::m_flags will be set based on ELF flag ABI.
Reviewers: ovyalov, clayborg
Subscribers: lldb-commits, mohit.bhakkad, sagar, jaydeep, bhushan
Differential: D18858
llvm-svn: 269181
This is not the right thing for all clients (notably the expression parser), so put it in type lookup specific code
Fixes rdar://problem/22422313
llvm-svn: 269095
Clear() log message was claiming it was the destructor, which had me very confused when looking
at the log messages. Fix the message, and add a log message to the real destructor.
Also noticed that the destructor was needlessly locking the broadcaster mutex (as Clear was
locking it again anyway), so remove that as well.
llvm-svn: 269058
IOHandlerLinesUpdated() does nothing, and IOHandlerIsInputComplete should be
implemented but isn't. This means that multiline expressions don't work. This
patch fixes that. Test case to follow in the next commit.
llvm-svn: 268970
llvm::Error requires all errors to be handled. Simply checking the whether there was an error is
not enough, you have to actuall call handle(All)Errors, in case there was an error.
llvm-svn: 268906
The IsValid calls can try to reconstruct the thread & frame, which can
take various internal locks. This can cause A/B locking issues with
the Target lock, so these calls need to that the Target lock.
llvm-svn: 268828
That's good 'cause it means all the different kinds of source line stepping won't leave user in the middle of
compiler implementation code or code inlined from odd places, etc. But it turns out that the compiler
also marks functions it MIGHT inline as all being of line 0. That would mean we single step through this code
instead of just stepping out. That is both inefficient, and more error prone 'cause these little nuggets tend
to be bits of hand-written assembly and the like and are hard to step through.
This change just checks and if the entire function is marked with line 0, we step out rather than step through.
<rdar://problem/25966460>
llvm-svn: 268823
"Allow LanguageRuntimes to return an error if they fail in the course of dynamic type discovery
This is not meant to report that a value doesn't have a dynamic type - it is only meant as a mechanism to propagate actual type discovery issues (e.g. malformed type metadata for languages that have such a notion)
This information is used by ValueObjectDynamic to set its own m_error, which is a fairly sharp and heavyweight tool to begin with
For the time being, this is an architectural improvement but a practical no-op as no existing runtimes are actually setting errors"
I need to think about what I want to do in this space more carefully - this attempt might be too heavy of a hammer for the nail I am trying to fix, and I don't want to leave it in while I ponder
llvm-svn: 268686
The function only avaibleble when python is enabled. Guard the new call
in the Java plugin with LLDB_DISABLE_PYTHON until we can change
AddCXXSynthetic to be available in all case to get the build bots green
again.
llvm-svn: 268626
now that the timeout actually means something, we see that sometimes adb is just really slow in
replying to the DONE packet during file push. Give it more time to complete.
llvm-svn: 268623
Summary:
AdbClient would spin in a loop in ReadAllBytes in case the remote end was closed before reading
the requested number of bytes. Make sure we return an error in this case instead.
Reviewers: ovyalov
Subscribers: tberghammer, danalbert, lldb-commits
Differential Revision: http://reviews.llvm.org/D19916
llvm-svn: 268617
Summary:
We were trying to get a DWARFDIE from a CompileUnit belonging to a DWO file. However, this
function does not understand the die encoding used by the DWO files. Instead use GetDIE on the
SymbolFileDWARF, which is overriden in DWO to do the right thing.
Reviewers: clayborg, tberghammer
Subscribers: lldb-commits, ovyalov
Differential Revision: http://reviews.llvm.org/D19927
llvm-svn: 268615
This is not meant to report that a value doesn't have a dynamic type - it is only meant as a mechanism to propagate actual type discovery issues (e.g. malformed type metadata for languages that have such a notion)
This information is used by ValueObjectDynamic to set its own m_error, which is a fairly sharp and heavyweight tool to begin with
For the time being, this is an architectural improvement but a practical no-op as no existing runtimes are actually setting errors
llvm-svn: 268591
1. Fixed semicolon placement in the lambda in the test itself.
2. Fixed lldbinline tests in general so that we don't attempt tests on platforms that don't use the given type of debug info. (For example, no DWO tests on Windows.) This fixes one of the two failures on Windows. (TestLambdas.py was the only inline test that wasn't XFailed or skipped on Windows.)
3. Set the error string in IRInterpreter::CanInterpret so that the caller doesn't print (null) instead of an explanation. I don't entirely understand the error, so feel free to suggest a better wording.
4. XFailed the test on Windows. The interpreter won't evaluate the lambda because the module has multiple function bodies. I don't exactly understand why that's a problem for the interpreter nor why the problem arises only on Windows.
Differential Revision: http://reviews.llvm.org/D19606
llvm-svn: 268573
We don't want a mutex in debugger as it will cause A/B locking issues with the lldb_private::Target's mutex, but we do need to stop two threads from doing Debugger::Clear at the same time. We have seen issues with this with the C++ global destructor chain where the global debugger list is being destroyed and the Debugger::~Debugger() is calling it while another thread was in the middle of running that function.
<rdar://problem/26098913>
llvm-svn: 268563
should not be used for this module -- for use when an ObjectFile
knows that it does not have meaningful or accurate function start
addresses.
More commonly, it is not clear that function start addresses are
missing in a module. There are certain cases on Mac OS X where we
can tell that a Mach-O binary has been stripped of this essential
information, and the unwinder can end up emulating many megabytes
of instructions for a single "function" in the binary.
When a Mach-O binary is missing both an LC_FUNCTION_STARTS load
command (very unusual) and an eh_frame section, then we will assume
it has also been stripped of symbols and that instruction emulation
will not be useful on this module.
<rdar://problem/25988067>
llvm-svn: 268475
the field_begin that starts the copy or it won't do anything.
This causes failures, but only in complex apps, I haven't found
a reduced test case for this yet.
<rdar://problem/21951798>
llvm-svn: 268467
Summary:
AdbClient was attempting to handle the case where the socket input arrived in pieces, but it was
failing to handle the case where the connection was closed before that happened. In this case, it
would just spin in an infinite loop calling Connection::Read. (This was also the cause of the
spurious timeouts on the darwin->android buildbot. The exact cause of the premature EOF remains
to be investigated, but is likely a server bug.)
Since this wait-for-a-certain-number-of-bytes seems like a useful functionality to have, I am
moving it (with the infinite loop fixed) to the Connection class, and adding an
appropriate test for it.
Reviewers: clayborg, zturner, ovyalov
Subscribers: tberghammer, danalbert, lldb-commits
Differential Revision: http://reviews.llvm.org/D19533
llvm-svn: 268380
Also added a data formatter that presents them as structs if you use frame
variable to look at their contents. Now the blocks testcase works.
<rdar://problem/15984431>
llvm-svn: 268307
In templated const functions, trying to run an expression would produce the
error
error: out-of-line definition of '$__lldb_expr' does not match any declaration
in 'foo' member declaration does not match because it is const qualified
error: 1 error parsing expression
which is no good. It turned out we don't actually need to worry about "const,"
we just need to be consistent about the declaration of the expression and the
FunctionDecl we inject into the class for "this."
Also added a test case.
<rdar://problem/24985958>
llvm-svn: 268083
This reverts commit r267833 as it breaks the build. It looks like some work in progress got
committed together with the actual fix, but I'm not sure which one is which, so I'll revert the
whole patch and let author resumbit it after fixing the build error.
llvm-svn: 267861
The code in ClangExpressionDeclMap::FindExternalVisibleDecls figures out what the token
means, and adds the namespace to the lookup context, but since it doesn't mark it as
special in the search context, we go on to pass the name $__lldb_local_vars to the ASTSource
for further lookup. Unless we've done our job wrong, those lookups will always fail, but
the can be costly.
So I added a bit to m_found & use that to short-circuit the lookup.
<rdar://problem/25613384>
llvm-svn: 267842
within a source file.
This isn't done, I need to make the name match smarter (right now it requires an
exact match which is annoying for methods of a class in a namespace.
Also, though we use it in tests all over the place, it doesn't look like we have
a test for Source Regexp breakpoints by themselves, I'll add that in a follow-on patch.
llvm-svn: 267834
In templated const functions, trying to run an expression would produce the
error
error: out-of-line definition of '$__lldb_expr' does not match any declaration in 'foo'
member declaration does not match because it is const qualified
error: 1 error parsing expression
which is no good. It turned out we don't actually need to worry about "const,"
we just need to be consistent about the declaration of the expression and the
FunctionDecl we inject into the class for "this."
Also added a test case.
<rdar://problem/24985958>
llvm-svn: 267833
Summary:
If the remote uses svr4 packets to communicate library info,
the LoadUnload tests will fail, as lldb only used the basename
for modules, causing problems when two modules have the same basename.
Using absolute path as sent by the remote will ensure that lldb
locates the module from the correct directory when there are overlapping
basenames. When debugging a remote process, LoadModuleAtAddress will still
fall back to using basename and module_search_paths, so we don't
need to worry about using absolute paths in this case.
Reviewers: ADodds, jasonmolenda, clayborg, ovyalov
Subscribers: lldb-commits, sas
Differential Revision: http://reviews.llvm.org/D19557
llvm-svn: 267741
to use the default clang C/C++ expression parser when debugging
Rust programs. Ideally there would be a rust language plugin to
support their language natively, but until then this will get simple
variable display to work.
http://reviews.llvm.org/D19545
llvm-svn: 267667
but when there's was no process it was just returning an null pointer
and not setting the error. I don't have a scenario where this might
go wrong, just code inspection...
llvm-svn: 267594
Remove case handling elf arm attribute Tag_THUMB_ISA_use and setting architecture to thumb.
Differential revision: http://reviews.llvm.org/D19520
llvm-svn: 267550
rL267291 introduces a lot regression on arm-linux LLDB testsuite.
This patch fixes half of them. I am merging it under already revied android counterpart.
Another patch fixing rest of the issue will follow this commit.
Differential revision: http://reviews.llvm.org/D19480
llvm-svn: 267508
statements for, be sure not to include variables that have no locations. We wouldn't
be able to realize them, and that will cause all expressions to fail.
llvm-svn: 267500
Summary:
If the remote uses include features when communicating
xml register info back to lldb, the existing code would reset the
lldb register index at the beginning of each include node.
This would lead to multiple registers having the same lldb register index.
Since the lldb register numbers should be contiguous and unique,
maintain them accross the parsing of all of the xml feature nodes.
Reviewers: jingham, jasonmolenda, clayborg
Subscribers: lldb-commits, sas
Differential Revision: http://reviews.llvm.org/D19303
llvm-svn: 267468
Summary:
When we receive an svr4 packet from the remote, we check for new modules
and add them to the list of images in the target. However, we did not
do the same for modules which have been removed.
This was causing TestLoadUnload to fail when using ds2, which uses
svr4 packets to communicate all library info on Linux. This patch fixes
the failing test.
Reviewers: zturner, tfiala, ADodds
Subscribers: lldb-commits, sas
Differential Revision: http://reviews.llvm.org/D19230
llvm-svn: 267467
Summary:
eRegisterKindProcessPlugin is used to store the register
indices used by the remote, and eRegisterKindLLDB is used
to store the internal lldb register indices. However, we're currently
using the lldb indices instead of the process plugin indices
when sending p/P packets. This will break if the remote uses
non-contiguous register indices.
Reviewers: jasonmolenda, clayborg
Subscribers: lldb-commits, sas
Differential Revision: http://reviews.llvm.org/D19305
llvm-svn: 267466
Make sure we figure out correct plt entry field in case linker has generated a small value below realistic entry size like 4 bytes or below.
Differential revision: http://reviews.llvm.org/D19252
llvm-svn: 267405
This option evaluates an expression and, if the result is of pointer type, treats it as if it was an array of that many elements and displays such elements
This has a couple subtle points but is mostly as straightforward as it sounds
Add a parray N <expr> alias for this new mode
Also, extend the --object-description mode to do the moral equivalent of the above but display each element in --object-description mode
Add a poarray N <expr> alias for this
llvm-svn: 267372
RegisterContextLLDB::InitializeNonZerothFrame already has code to attempt
to detect and handle the case where the PC points beyond the end of a
function, but there are certain cases where this doesn't work correctly.
In fact, there are *two* different places where this detection is attempted,
and the failure is in fact a result of an unfortunate interaction between
those two separate attempts.
First, the ResolveSymbolContextForAddress routine is called with the
resolve_tail_call_address flag set to true. This causes the routine
to internally accept a PC pointing beyond the end of a function, and
still resolving the PC to that function symbol.
Second, the InitializeNonZerothFrame routine itself maintains a
"decr_pc_and_recompute_addr_range" flag and, if that turns out to
be true, itself decrements the PC by one and searches again for
a symbol at that new PC value.
Both approaches correctly identify the symbol associated with the PC.
However, the problem is now that later on, we also need to find the
DWARF CFI record associated with the PC. This is done in the
RegisterContextLLDB::GetFullUnwindPlanForFrame routine, and uses
the "m_current_offset_backed_up_one" member variable.
However, that variable only actually contains the PC "backed up by
one" if the *second* approach above was taken. If the function was
already identified via the first approach above, that member variable
is *not* backed up by one but simply points to the original PC.
This in turn causes GetEHFrameUnwindPlan to not correctly identify
the DWARF CFI record associated with the PC.
Now, in many cases, if the first method had to back up the PC by one,
we *still* use the second method too, because of this piece of code:
// Or if we're in the middle of the stack (and not "above" an asynchronous event like sigtramp),
// and our "current" pc is the start of a function...
if (m_sym_ctx_valid
&& GetNextFrame()->m_frame_type != eTrapHandlerFrame
&& GetNextFrame()->m_frame_type != eDebuggerFrame
&& addr_range.GetBaseAddress().IsValid()
&& addr_range.GetBaseAddress().GetSection() == m_current_pc.GetSection()
&& addr_range.GetBaseAddress().GetOffset() == m_current_pc.GetOffset())
{
decr_pc_and_recompute_addr_range = true;
}
In many cases, when the PC is one beyond the end of the current function,
it will indeed then be exactly at the start of the next function. But this
is not always the case, e.g. if there happens to be alignment padding
between the end of one function and the start of the next.
In those cases, we may sucessfully look up the function symbol via
ResolveSymbolContextForAddress, but *not* set decr_pc_and_recompute_addr_range,
and therefore fail to find the correct DWARF CFI record.
A very simple fix for this problem is to just never use the first method.
Call ResolveSymbolContextForAddress with resolve_tail_call_address set
to false, which will cause it to fail if the PC is beyond the end of
the current function; or else, identify the next function if the PC
is also at the start of the next function. In either case, we will
then set the decr_pc_and_recompute_addr_range variable and back up the
PC anyway, but this time also find the correct DWARF CFI.
A related problem is that the ResolveSymbolContextForAddress sometimes
returns a "symbol" with empty name. This turns out to be an ELF section
symbol. Now, usually those get type eSymbolTypeInvalid. However, there
is code in ObjectFileELF::ParseSymbols that tries to change the type of
invalid symbols to eSymbolTypeCode or eSymbolTypeData if the symbol
lies within the code or data section.
Unfortunately, this check also hits the symbol for the code section
itself, which is then marked as eSymbolTypeCode. While the size of
the section symbol is 0 according to the ELF file, LLDB considers
this size invalid and attempts to figure out the "correct" size.
Depending on how this goes, we may end up with a symbol that overlays
part of the code section, even outside areas covered by real function
symbols.
Therefore, if we call ResolveSymbolContextForAddress with PC pointing
beyond the end of a function, we may get this bogus section symbol.
This again means InitializeNonZerothFrame thinks we have a valid PC,
but then we don't find any unwind info for it.
The fix for this problem is me to simply always leave ELF section
symbols as type eSymbolTypeInvalid.
Differential Revision: http://reviews.llvm.org/D18975
llvm-svn: 267363
This adds basic parsing of the EABI attributes section. This section contains
additional information about the target for which the file was built. Attempt
to infer additional architecture information from that section.
llvm-svn: 267291
Some older versions of clang emitted bit offsets that were negative and these bitfields would have their bitfield-ness stripped off and it would cause a clang assertion in clang assertions were enabled. I updated the bitfield C test to make sure we don't regress.
<rdar://problem/21082998>
llvm-svn: 267248
Conditionalise a variable definition which may be unused in certain compilations
due to the preprocessor. Protect the variable accordingly. NFC.
llvm-svn: 267247
Code was added in ClangExpressionParser::ClangExpressionParser that was calling through
the process w/o checking that it was good. Also, we were pretending that we could do something
reasonable if we had no target, but that's actually not true, so I check for a target at the
beginning of the constructor and don't make a compiler in that case.
<rdar://problem/25841198>
llvm-svn: 266944
When stopping the private state thread, there was a race condition between the time the thread exits (resetting the HostThread object) and the time a Join was attempted, especially in the case of a timeout.
The previous workaround of copying the HostThread object is not enough, since on a Reset the internal thread stuff gets nulled out regardless of which HostThread object actually has Reset called on it, resulting in an attempt to dereference a null pointer on the subsequent call to Join from the copy as well.
Additionally, there was a race between the detach (called when stopping the process) and the stop itself, causing the stop to time out because it was waiting for the private state thread to see the stop state, but it had exited immediately after entering the detached state.
Patch by cameron314
Differential Revision: http://reviews.llvm.org/D19122
llvm-svn: 266733
Summary:
Doing a pthread_detach while the thread is exiting can cause crashes or other mischief, so we
make sure the thread stays around long enough. The performance impact of the added
synchronization should be minimal, as the parent thread is already holding a mutex, so I am just
making sure it holds it for a little while longer. It's possible the new thread will block on
this mutex immediately after startup, but it should be unblocked really quickly and some
blocking is unavoidable if we actually want to have this synchronization.
Reviewers: tberghammer
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D19153
llvm-svn: 266423
Recommit modified version of r266311 including build bot regression fix.
This differs from the original r266311 by:
- Fixing Scalar::Promote to correctly zero- or sign-extend value depending
on signedness of the *source* type, not the target type.
- Omitting a few stand-alone fixes that were already committed separately.
llvm-svn: 266422
This routine contained a stray "return false;" making part of the code
never executed. Also, the stack offset where to find on-stack arguments
was incorrect.
llvm-svn: 266417
This implements a PDBASTParser and corresponding logic in
SymbolFilePDB to do type lookup by name. This is just a first
pass and leaves many aspects of type lookup unimplemented, and
just focuses on laying the framework. With this patch, you should
be able to lookup basic types by name from a PDB.
Full class definitions are not completed yet, we will instead
just return a forward declaration of the class.
Differential Revision: http://reviews.llvm.org/D18848
Reviewed by: Greg Clayton
llvm-svn: 266392
Code in ObjectFileELF::ParseTrampolineSymbols assumes that the sh_info
field of the .rel(a).plt section identifies the .plt section.
However, with recent GNU ld this is no longer true. As a result of this:
https://sourceware.org/bugzilla/show_bug.cgi?id=18169
in object files generated with current linkers the sh_info field of
.rel(a).plt now points to the .got.plt section (or .got on some targets).
This causes LLDB to fail to identify any PLT stubs, causing a number of
test case failures.
This patch changes LLDB to simply always look for the .plt section by
name. This should be safe across all linkers and targets.
Differential Revision: http://reviews.llvm.org/D18973
llvm-svn: 266316
Running the ARM instruction emulation test on a big-endian system
would fail, since the code doesn't respect endianness properly.
In EmulateInstructionARM::TestEmulation, code assumes that an
instruction opcode read in from the test file is in target byte
order, but it was in fact read in in host byte order.
More difficult to fix, the EmulationStateARM structure models
the overlapping sregs and dregs by a union in _sd_regs. This
only works correctly if the host is a little-endian system.
I've removed the union in favor of a simple array containing
the 32 sregs, and changed any code accessing dregs to explicitly
use the correct two sregs overlaying that dreg in the proper
target order.
Also, the EmulationStateARM::ReadPseudoMemory and WritePseudoMemory
track memory as a map of uint32_t values in host byte order, and
implement 64-bit memory accessing by splitting them up into two
uint32_t ones. However, callers expect memory contents to be
provided in the form of a byte array (in target byte order).
This means the uint32_t contents need to be byte-swapped on
BE systems, and when splitting up a 64-bit access into two 32-bit
ones, byte order has to be respected.
Differential Revision: http://reviews.llvm.org/D18984
llvm-svn: 266314
This patch fixes a bunch of issues that show up on big-endian systems:
- The gnu_libstdcpp.py script doesn't follow the way libstdc++ encodes
bit vectors: it should identify the enclosing *word* and then access
the appropriate bit within that word. Instead, the script simply
operates on bytes. This gives the same result on little-endian
systems, but not on big-endian.
- lldb_private::formatters::WCharSummaryProvider always assumes wchar_t
is UTF16, even though it could also be UTF8 or UTF32. This is mostly
not an issue on little-endian systems, but immediately fails on BE.
Fixed by checking the size of wchar_t like WCharStringSummaryProvider
already does.
- ClangASTContext::GetChildCompilerTypeAtIndex uses uint32_t to access
the virtual base offset stored in the vtable, even though the size
of this field matches the target pointer size according to the C++
ABI. Again, this is mostly not visible on LE, but fails on BE.
- Process::ReadStringFromMemory uses strncmp to search for a terminator
consisting of multiple zero bytes. This doesn't work since strncmp
will stop already at the first zero byte. Use memcmp instead.
Differential Revision: http://reviews.llvm.org/D18983
llvm-svn: 266313
Currently, the DataExtractor::GetMaxU64Bitfield and GetMaxS64Bitfield
routines assume the incoming "bitfield_bit_offset" parameter uses
little-endian bit numbering, i.e. a bitfield_bit_offset 0 refers to
a bitfield whose least-significant bit coincides with the least-
significant bit of the surrounding integer.
On many big-endian systems, however, the big-endian bit numbering
is used for bit fields. Here, a bitfield_bit_offset 0 refers to
a bitfield whose most-significant bit conincides with the most-
significant bit of the surrounding integer.
Now, in principle LLDB could arbitrarily choose which semantics of
bitfield_bit_offset to use. However, there are two problems with
the current approach:
- When parsing DWARF, LLDB decodes bit offsets in little-endian
bit numbering on LE systems, but in big-endian bit numbering
on BE systems. Passing those offsets later on into the
DataExtractor routines gives incorrect results on BE.
- In the interim, LLDB's type layer combines byte and bit offsets
into a single number. I.e. instead of recording bitfields by
specifying the byte offset and byte size of the surrounding
integer *plus* the bit offset of the bit field within that field,
it simply records a single bit offset number.
Now, note that converting from byte offset + bit offset to a
single offset value and back is well-defined if we either use
little-endian byte order *and* little-endian bit numbering,
or use big-endian byte order *and* big-endian bit numbering.
Any other combination will yield incorrect results.
Therefore, the simplest approach would seem to be to always use
the bit numbering that matches the system byte order. This makes
storing a single bit offset valid, and makes the existing DWARF
code correct. The only place to fix is to teach DataExtractor
to use big-endian bit numbering on big endian systems.
However, there is only additional caveat: we also get bit offsets
from LLDB synthetic bitfields. While the exact semantics of those
doesn't seem to be well-defined, from test cases it appears that
the intent was for the user-provided synthetic bitfield offset to
always use little-endian bit numbering. Therefore, on a big-endian
system we now have to convert those to big-endian bit numbering
to remain consistent.
Differential Revision: http://reviews.llvm.org/D18982
llvm-svn: 266312
Pavel Labath