The Scalar implementation and a few other places in LLDB directly
access the internal implementation of APInt values using the
getRawData method. Unfortunately, pretty much all of these places
do not handle big-endian systems correctly. While on little-endian
machines, the pointer returned by getRawData can simply be used as
a pointer to the integer value in its natural format, no matter
what size, this is not true on big-endian systems: getRawData
actually points to an array of type uint64_t, with the first element
of the array always containing the least-significant word of the
integer. This means that if the bitsize of that integer is smaller
than 64, we need to add an offset to the pointer returned by
getRawData in order to access the value in its natural type, and
if the bitsize is *larger* than 64, we actually have to swap the
constituent words before we can access the value in its natural type.
This patch fixes every incorrect use of getRawData in the code base.
For the most part, this is done by simply removing uses of getRawData
in the first place, and using other APInt member functions to operate
on the integer data.
This can be done in many member functions of Scalar itself, as well
as in Symbol/Type.h and in IRInterpreter::Interpret. For the latter,
I've had to add a Scalar::MakeUnsigned routine to parallel the existing
Scalar::MakeSigned, e.g. in order to implement an unsigned divide.
The Scalar::RawUInt, Scalar::RawULong, and Scalar::RawULongLong
were already unused and can be simply removed. I've also removed
the Scalar::GetRawBits64 function and its few users.
The one remaining user of getRawData in Scalar.cpp is GetBytes.
I've implemented all the cases described above to correctly
implement access to the underlying integer data on big-endian
systems. GetData now simply calls GetBytes instead of reimplementing
its contents.
Finally, two places in the clang interface code were also accessing
APInt.getRawData in order to actually construct a byte representation
of an integer. I've changed those to make use of a Scalar instead,
to avoid having to re-implement the logic there.
The patch also adds a couple of unit tests verifying correct operation
of the GetBytes routine as well as the conversion routines. Those tests
actually exposed more problems in the Scalar code: the SetValueFromData
routine didn't work correctly for 128- and 256-bit data types, and the
SChar routine should have an explicit "signed char" return type to work
correctly on platforms where char defaults to unsigned.
Differential Revision: http://reviews.llvm.org/D18981
llvm-svn: 266311
Scalar::GetBytes provides a non-const access to the underlying bytes
of the scalar value, supposedly allowing for modification of those
bytes. However, even with the current implementation, this is not
really possible. For floating-point scalars, the pointer returned
by GetBytes refers to a temporary copy; modifications to that copy
will be simply ignored. For integer scalars, the pointer refers
to internal memory of the APInt implementation, which isn't
supposed to be directly modifyable; GetBytes simply casts aways
the const-ness of the pointer ...
With my upcoming patch to fix Scalar::GetBytes for big-endian
systems, this problem is going to get worse, since there we need
temporary copies even for some integer scalars. Therefore, this
patch makes Scalar::GetBytes const, fixing all those problems.
As a follow-on change, RegisterValues::GetBytes must be made const
as well. This in turn means that the way of initializing a
RegisterValue by doing a SetType followed by writing to GetBytes
no longer works. Instead, I've changed SetValueFromData to do
the equivalent of SetType itself, and then re-implemented
SetFromMemoryData to work on top of SetValueFromData.
There is still a need for RegisterValue::SetType, since some
platform-specific code uses it to reinterpret the contents of
an already filled RegisterValue. To make this usage work in
all cases (even changing from a type implemented via Scalar
to a type implemented as a byte buffer), SetType now simply
copies the old contents out, and then reloads the RegisterValue
from this data using the new type via SetValueFromData.
This in turn means that there is no remaining caller of
Scalar::SetType, so it can be removed.
The only other follow-on change was in MIPS EmulateInstruction
code, where some uses of RegisterValue::GetBytes could be made
const trivially.
Differential Revision: http://reviews.llvm.org/D18980
llvm-svn: 266310
This fixes several test case failure on s390x caused by the fact that
on this platform, the default "char" type is unsigned.
- In ClangASTContext::GetBuiltinTypeForEncodingAndBitSize we should return
an explicit *signed* char type for encoding eEncodingSint and bit size 8,
instead of the default platform char type (which may be unsigned).
This fix matches existing code in ClangASTContext::GetIntTypeFromBitSize,
and fixes the TestClangASTContext.TestBuiltinTypeForEncodingAndBitSize
unit test case.
- The test/expression_command/char/TestExprsChar.py test case is known to
fail on platforms defaulting to unsigned char (pr23069), and just needs
to be xfailed on s390x like on arm.
- The test/functionalities/watchpoint/watchpoint_on_vectors/main.c test
case defines a vector of "char" and implicitly assumes to be signed.
Use an explicit "signed char" instead.
Differential Revision: http://reviews.llvm.org/D18979
llvm-svn: 266309
This patch adds support for Linux on SystemZ:
- A new ArchSpec value of eCore_s390x_generic
- A new directory Plugins/ABI/SysV-s390x providing an ABI implementation
- Register context support
- Native Linux support including watchpoint support
- ELF core file support
- Misc. support throughout the code base (e.g. breakpoint opcodes)
- Test case updates to support the platform
This should provide complete support for debugging the SystemZ platform.
Not yet supported are optional features like transaction support (zEC12)
or SIMD vector support (z13).
There is no instruction emulation, since our ABI requires that all code
provide correct DWARF CFI at all PC locations in .eh_frame to support
unwinding (i.e. -fasynchronous-unwind-tables is on by default).
The implementation follows existing platforms in a mostly straightforward
manner. A couple of things that are different:
- We do not use PTRACE_PEEKUSER / PTRACE_POKEUSER to access single registers,
since some registers (access register) reside at offsets in the user area
that are multiples of 4, but the PTRACE_PEEKUSER interface only allows
accessing aligned 8-byte blocks in the user area. Instead, we use a s390
specific ptrace interface PTRACE_PEEKUSR_AREA / PTRACE_POKEUSR_AREA that
allows accessing a whole block of the user area in one go, so in effect
allowing to treat parts of the user area as register sets.
- SystemZ hardware does not provide any means to implement read watchpoints,
only write watchpoints. In fact, we can only support a *single* write
watchpoint (but this can span a range of arbitrary size). In LLDB this
means we support only a single watchpoint. I've set all test cases that
require read watchpoints (or multiple watchpoints) to expected failure
on the platform. [ Note that there were two test cases that install
a read/write watchpoint even though they nowhere rely on the "read"
property. I've changed those to simply use plain write watchpoints. ]
Differential Revision: http://reviews.llvm.org/D18978
llvm-svn: 266308
If the UnwindPlan did not identify how to unwind the stack pointer
register, LLDB currently assumes it can determine to caller's SP
from the current frame's CFA. This is true on most platforms
where CFA is by definition equal to the incoming SP at function
entry.
However, on the s390x target, we instead define the CFA to equal
the incoming SP plus an offset of 160 bytes. This is because
our ABI defines that the caller has to provide a register save
area of size 160 bytes. This area is allocated by the caller,
but is considered part of the callee's stack frame, and therefore
the CFA is defined as pointing to the top of this area.
In order to make this work on s390x, this patch introduces a new
ABI callback GetFallbackRegisterLocation that provides platform-
specific fallback register locations for unwinding. The existing
code to handle SP unwinding as well as volatile registers is moved
into the default implementation of that ABI callback, to allow
targets where that implementation is incorrect to override it.
This patch in itself is a no-op for all existing platforms.
But it is a pre-requisite for adding s390x support.
Differential Revision: http://reviews.llvm.org/D18977
llvm-svn: 266307
That was removed in r266304, but leads to warnings by Clang.
Thanks to Rafael Espíndola for pointing on that.
Though I think change was legal from point of C++.
llvm-svn: 266306
The PS_STRINGS constant can easily be incorrect with mismatched
kernel/userland - e.g. when building i386 sanitizers on FreeBSD/amd64
with -m32. The kern.ps_strings sysctl was introduced over 20 years ago
as the supported way to fetch the environment and argument string
addresses from the kernel, so the fallback is never used.
Differential Revision: http://reviews.llvm.org/D19027
llvm-svn: 266305
Alias 'jic $reg, 0' to 'jrc $reg' and 'jialc $reg, 0' to 'jalrc $reg' like
binutils.
This patch was previous committed as r266055 as seemed to have caused some spurious
test failures. They did not reappear after further local testing.
llvm-svn: 266301
In short, CVE-2016-2143 will crash the machine if a process uses both >4TB
virtual addresses and fork(). ASan, TSan, and MSan will, by necessity, map
a sizable chunk of virtual address space, which is much larger than 4TB.
Even worse, sanitizers will always use fork() for llvm-symbolizer when a bug
is detected. Disable all three by aborting on process initialization if
the running kernel version is not known to contain a fix.
Unfortunately, there's no reliable way to detect the fix without crashing
the kernel. So, we rely on whitelisting - I've included a list of upstream
kernel versions that will work. In case someone uses a distribution kernel
or applied the fix themselves, an override switch is also included.
Differential Revision: http://reviews.llvm.org/D18915
llvm-svn: 266297
This teaches sanitizer_common about s390 and s390x virtual space size.
s390 is unusual in that it has 31-bit virtual space.
Differential Revision: http://reviews.llvm.org/D18896
llvm-svn: 266296
mmap on s390 is quite a special snowflake: since it has too many
parameters to pass them in registers, it passes a pointer to a struct
with all the parameters instead.
Differential Revision: http://reviews.llvm.org/D18889
llvm-svn: 266295
The example below should work identically with and without compiler native
wchar_t support.
void foo(wchar_t * t = L"");
Differential Revision: http://reviews.llvm.org/D19056
llvm-svn: 266287
Summary:
In D18689, I removed the call to Normalize() in FileSpec::SetFile, because it no longer seemed
needed, and it resolved a quirk in the FileSpec API (spec.GetCString() returnes a path with
backslashes, but spec.GetDirectory().GetCString() has forward slashes). This turned out to be a
problem because we would consider paths with different separators as different (which led to
unresolved breakpoints for instance).
Here, I am putting back in the call to Normalize() and adding a unittest for FileSpec::Equal. I
am commenting out the GetDirectory unittests until we figure out the what is the expected
behaviour here.
Reviewers: zturner
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D19060
llvm-svn: 266286
Summary:
The only difference between the removed tests and the pre-existing
ones, is the materialization of the zero constant, which shouldn't
matter for these cases.
Reviewers: dsanders, sdardis
Subscribers: dsanders, sdardis, llvm-commits
Differential Revision: http://reviews.llvm.org/D18693
llvm-svn: 266285
The custom zone implementation for OS X must not return 0 (even for 0-sized allocations). Returning 0 indicates that the pointer doesn't belong to the zone. This can break existing applications. The underlaying allocator allocates 1 byte for 0-sized allocations anyway, so returning 1 in this case is okay.
Differential Revision: http://reviews.llvm.org/D19100
llvm-svn: 266283
The behavior of {MIN,MAX}NAN differs from that of {MIN,MAX}NUM when only
one of the inputs is NaN: -NUM will return the non-NaN argument while
-NAN would return NaN.
It is desirable to lower to @llvm.{min,max}num to -NAN if they don't
have a native instruction for -NUM. Notably, ARMv7 NEON's vmin has the
-NAN semantics.
N.B. Of course, it is only safe to do this if the intrinsic call is
marked nnan.
llvm-svn: 266279
This code was creating a new type in the global context, regardless
of which context the user is sitting in, what can possibly go wrong?
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266275
They are unnecessary, as the dynamic loader can apply the original relocations
directly. This was also resulting in the creation of copy relocations in PIEs.
Differential Revision: http://reviews.llvm.org/D19089
llvm-svn: 266273
Summary:
AllKindInfo is being indexed by NodeKindId, so the order must match.
Extended ASTTypeTraits tests to cover this.
Reviewers: sbenza
Subscribers: cfe-commits, klimek
Differential Revision: http://reviews.llvm.org/D19059
llvm-svn: 266268
a table entry in the corresponding decl, store an offset from the current
record to the relevant CXX_BASE_SPECIFIERS record. This results in fewer
indirections and a minor .pcm file size reduction.
llvm-svn: 266266
r265877 tries to put methods that are deprecated or unavailable to the
front of the global pool to emit diagnostics, but it breaks some of
our existing codes that depend on choosing a certain method for id
lookup.
This commit orders the methods with the same declaration with respect
to the availability, but do not order methods with different declaration.
rdar://25707511
llvm-svn: 266264
Non-owning pointers that cache LLVM types and constants can use
'nullptr' default member initializers so that we don't need to mention
them in the constructor initializer list.
Owning pointers should use std::unique_ptr so that we don't need to
manually delete them in the destructor. They also don't need to be
mentioned in the constructor at that point.
NFC
llvm-svn: 266263
Ulrich Weigand