The issue with Thumb IT (if/then) instructions is the IT instruction preceeds up to four instructions that are made conditional. If a breakpoint is placed on one of the conditional instructions, the instruction either needs to match the thumb opcode size (2 or 4 bytes) or a BKPT instruction needs to be used as these are always unconditional (even in a IT instruction). If BKPT instructions are used, then we might end up stopping on an instruction that won't get executed. So if we do stop at a BKPT instruction, we need to continue if the condition is not true.
When using the BKPT isntructions are easy in that you don't need to detect the size of the breakpoint that needs to be used when setting a breakpoint even in a thumb IT instruction. The bad part is you will now always stop at the opcode location and let LLDB determine if it should auto-continue. If the BKPT instruction is used, the BKPT that is used for ARM code should be something that also triggers the BKPT instruction in Thumb in case you set a breakpoint in the middle of code and the code is actually Thumb code. A value of 0xE120BE70 will work since the lower 16 bits being 0xBE70 happens to be a Thumb BKPT instruction.
The alternative is to use trap or illegal instructions that the kernel will translate into breakpoint hits. On Mac this was 0xE7FFDEFE for ARM and 0xDEFE for Thumb. The darwin kernel currently doesn't recognize any 32 bit Thumb instruction as a instruction that will get turned into a breakpoint exception (EXC_BREAKPOINT), so we had to use the BKPT instruction on Mac. The linux kernel recognizes a 16 and a 32 bit instruction as valid thumb breakpoint opcodes. The benefit of using 16 or 32 bit instructions is you don't stop on opcodes in a IT block when the condition doesn't match.
To further complicate things, single stepping on ARM is often implemented by modifying the BCR/BVR registers and setting the processor to stop when the PC is not equal to the current value. This means single stepping is another way the ARM target can stop on instructions that won't get executed.
This patch does the following:
1 - Fix the internal debugserver for Apple to use the BKPT instruction for ARM and Thumb
2 - Fix LLDB to catch when we stop in the middle of a Thumb IT instruction and continue if we stop at an instruction that won't execute
3 - Fixes this in a way that will work for any target on any platform as long as it is ARM/Thumb
4 - Adds a patch for ignoring conditions that don't match when in ARM mode (see below)
This patch also provides the code that implements the same thing for ARM instructions, though it is disabled for now. The ARM patch will check the condition of the instruction in ARM mode and continue if the condition isn't true (and therefore the instruction would not be executed). Again, this is not enable, but the code for it has been added.
<rdar://problem/19145455>
llvm-svn: 223851
ObjectFileMachO. It's close but we seem to be missing some
of the memory region segments - not exactly sure how that's
happening. The register context writing into the LC_THREAD
load commands is working correctly though.
Slightly reordered the arm64 definitions in ArchSpec.cpp so
when we look for an arm64 core file definiton we're getting
a cpu subtype of CPU_ANY which we can't put in the mach
header of a core file. Make the first definition we find by
linear search have the currently correct '1' cpu subtype.
llvm-svn: 221743
Summary:
Ed Maste found some problems with the commit in D5988. Address most of these.
While here, also add floating point return handling. This doesn't handle
128-bit long double yet. Since I don't have any system that uses it, I don't
currently have plans to implement it.
Reviewers: emaste
Reviewed By: emaste
Subscribers: emaste, lldb-commits
Differential Revision: http://reviews.llvm.org/D6049
llvm-svn: 220963
Summary:
This adds preliminary support for PowerPC/PowerPC64, for FreeBSD. There are
some issues still:
* Breakpoints don't work well on powerpc64.
* Shared libraries don't yet get loaded for a 32-bit process on powerpc64 host.
* Backtraces don't work. This is due to PowerPC ABI using a backchain pointer
in memory, instead of a dedicated frame pointer register for the backchain.
* Breakpoints on functions without debug info may not work correctly for 32-bit
powerpc.
Reviewers: emaste, tfiala, jingham, clayborg
Reviewed By: clayborg
Subscribers: emaste, lldb-commits
Differential Revision: http://reviews.llvm.org/D5988
llvm-svn: 220944
works, as do breakpoints, run and pause, display zeroth frame.
See
http://reviews.llvm.org/D5503
for a fuller description of the changes in this commit.
llvm-svn: 218596
Add entries to core_definitions and elf_arch_entries for
those variants. Select the subtype for the variant by parsing
the e_flags field of the elf header.
llvm-svn: 216541
i386, i486, i486sx, and i686 are all indistinguishable as far as
PE/COFF files are concerned. This patch adds support for all of
these architectures to PlatformWindows.
Differential Revision: http://reviews.llvm.org/D4658
llvm-svn: 214092
We now catch the issue with a static_assert() at compile time and use llvm::array_lengthof(g_core_definitions) as well.
<rdar://problem/17767541>
llvm-svn: 213778
See the following llvm change for details:
r213743 | tnorthover | 2014-07-23 05:32:47 -0700 (Wed, 23 Jul 2014) | 9 lines
AArch64: remove arm64 triple enumerator.
This change fixes build breaks on Linux and MacOSX lldb.
llvm-svn: 213755
This change comprises of additions and some minor changes in order that
"kalimba" is listed as a supported platform and that debugging any
kalimbas results in PlatformKalimba being associated with the target.
The changes are as follows:
* The PlatformKalimba implementation itself
* A tweak to ArchSpec
* .note parsing for Kalimba in ObjectFileELF.cpp
* Plugin registration
* Makefile additions
Change by Matthew Gardiner
Minor tweak for cmake and Xcode by Todd Fiala
Tested:
Ubuntu 14.04 x86_64, clang 3.5-built lldb, all tests pass.
MacOSX 10.9.4, Xcode 6.0 Beta 1-built lldb, all tests pass.
llvm-svn: 213158
Fixes include:
- Don't say that "<arch>-apple-ios" is compatible with "<arch>-apple-macosx"
- Fixed DynamicLoaderMacOSXDYLD so specify an architecture that was converted solely from a cputype and subtype, just specify the file + UUID.
- Fixed PlatformiOSSimulator::GetSupportedArchitectureAtIndex() so it returns the correct archs
- Fixed SymbolFileDWARFDebugMap to load .o files correctly by just specifying the architecture without the vendor and OS now that "<arch>-apple-ios" is not compatible with "<arch>-apple-macosx" so we can load .o files correctly for DWARF with debug map
- Fixed the coded in TargetList::CreateTarget() so it does the right thing with an underspecified triple where just the arch is specified.
llvm-svn: 212783
Replace adhoc inline implementation of llvm::array_lengthof in favour of the
implementation in LLVM. This is simply a cleanup change, no functional change
intended.
llvm-svn: 211868
Changes include:
- ObjectFileMachO can now determine if a binary is "*-apple-ios" or "*-apple-macosx" by checking the min OS and SDK load commands
- ArchSpec now says "<arch>-apple-macosx" is equivalent to "<arch>-apple-ios" since the simulator mixes and matches binaries (some from the system and most from the iOS SDK).
- Getting process inforamtion on MacOSX now correctly classifies iOS simulator processes so they have "*-apple-ios" architectures in the ProcessInstanceInfo
- PlatformiOSSimulator can now list iOS simulator processes correctly instead of showing nothing by using:
(lldb) platform select ios-simulator
(lldb) platform process list
- debugserver can now properly return "*-apple-ios" for the triple in the process info packets for iOS simulator executables
- GDBRemoteCommunicationClient now correctly passes along the triples it gets for process info by setting the OS in the llvm::Triple correctly
<rdar://problem/17060217>
llvm-svn: 209852
These changes were written by Greg Clayton, Jim Ingham, Jason Molenda.
It builds cleanly against TOT llvm with xcodebuild. I updated the
cmake files by visual inspection but did not try a build. I haven't
built these sources on any non-Mac platforms - I don't think this
patch adds any code that requires darwin, but please let me know if
I missed something.
In debugserver, MachProcess.cpp and MachTask.cpp were renamed to
MachProcess.mm and MachTask.mm as they picked up some new Objective-C
code needed to launch processes when running on iOS.
llvm-svn: 205113
ArchSpec now contains an optional distribution_id, with getters and
setters. Host::GetArchitecture () sets it on non-Apple platforms using
Host::GetDistributionId (). The distribution_id is ignored during
ArchSpec comparisons.
The gdb remote qHostInfo message transmits it, if set, via the
distribution_id={id-value} key/value pair. Updated gdb remote docs to
reflect this change.
As before, GetDistributionId () returns nothing on non-Linux platforms
at this time. On Linux, it is returned only if the lsb_platform
command is installed (in /bin or /usr/bin), and only if the
distributor id key is returned by 'lsb_platform -i'. This id is
lowercased, and whitespace is replaced with underscores.
llvm-svn: 199539
Based on the POSIX x86_64 register context. This is sufficient for opening
a mips64 (big endian) core file. Subsequent changes will connect the
disassembler, dynamic loader support, ABI, etc.
Review: http://llvm-reviews.chandlerc.com/D1873
llvm-svn: 192335
Since I renamed most of the LLVM Mach-O enums in r189314, I had to go fix
LLDB to use the new names. While I was here, I decided that a COFF
plugin really shouldn't be using Mach-O enums.
llvm-svn: 189316
Major fixed to allow reading files that are over 4GB. The main problems were that the DataExtractor was using 32 bit offsets as a data cursor, and since we mmap all of our object files we could run into cases where if we had a very large core file that was over 4GB, we were running into the 4GB boundary.
So I defined a new "lldb::offset_t" which should be used for all file offsets.
After making this change, I enabled warnings for data loss and for enexpected implicit conversions temporarily and found a ton of things that I fixed.
Any functions that take an index internally, should use "size_t" for any indexes and also should return "size_t" for any sizes of collections.
llvm-svn: 173463
Fixed an issue where the platform auto select code was changing the architecture and causing the wrong architecture to be assigned to the target.
llvm-svn: 172251
equality can be strict or loose and we want code to
explicitly choose one or the other.
Also renamed the Compare function to IsEqualTo, to
avoid confusion.
<rdar://problem/12856749>
llvm-svn: 170152
The operator== method is a synonym for IsExactMatch().
The essential difference between these two is that IsCompatibleMatch()
will say that armv7 and armv7s are compatible and return true.
IsExactMatch() will say that armv7 and armv7s are not a match.
An armv7s cpu can run either generic armv7 binaries or armv7s binaries
(the latter being tuned for it). When we're picking the slice of a
universal Mach-O file to load in an armv7s Target, we need to be able to
first look for an exact cpu subtype match (armv7s == armv7s) and failing
that, looking for a slice with a compatible architecture.
Update ObjectContainerUniversalMachO::GetObjectFile to prefer an exact
match of the cpu type, falling back to a compatible match if necessary.
<rdar://problem/12593515>
llvm-svn: 167365
Fix a subtle ArchSpec::cores_match() logic issue which prevents the add-dsym command
to add a debug symbol file to one of the target's current modules.
llvm-svn: 162802
Switch over to the "*-apple-macosx" for desktop and "*-apple-ios" for iOS triples.
Also make the selection process for auto selecting platforms based off of an arch much better.
llvm-svn: 156354
C++ vtables, fixing a record layout problem in the
expression parser.
Also fixed various problems with the generation
and unpacking of llvm.zip given our new better
handling of multiple architectures in the LLVM
build.
(And added a log message that will hopefully catch
record layout problems in the future.)
llvm-svn: 143741
Greg Clayton