While this does not matter for most targets, when building for Arm Morello,
we have to mark the symbol as a function and add size information, so that
LLD can correctly evaluate relocations against the local symbol.
Since Morello is an out-of-tree target, I tried to reproduce this with
in-tree backends and with the previous reviews applied this results in
a noticeable difference when targeting Thumb.
Background: Morello uses a method similar Thumb where the encoding mode is
specified in the LSB of the symbol. If we don't mark the target as a
function, the relocation will not have the LSB set and calls will end up
using the wrong encoding mode (which will almost certainly crash).
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D131429
The KCFI sanitizer, enabled with `-fsanitize=kcfi`, implements a
forward-edge control flow integrity scheme for indirect calls. It
uses a !kcfi_type metadata node to attach a type identifier for each
function and injects verification code before indirect calls.
Unlike the current CFI schemes implemented in LLVM, KCFI does not
require LTO, does not alter function references to point to a jump
table, and never breaks function address equality. KCFI is intended
to be used in low-level code, such as operating system kernels,
where the existing schemes can cause undue complications because
of the aforementioned properties. However, unlike the existing
schemes, KCFI is limited to validating only function pointers and is
not compatible with executable-only memory.
KCFI does not provide runtime support, but always traps when a
type mismatch is encountered. Users of the scheme are expected
to handle the trap. With `-fsanitize=kcfi`, Clang emits a `kcfi`
operand bundle to indirect calls, and LLVM lowers this to a
known architecture-specific sequence of instructions for each
callsite to make runtime patching easier for users who require this
functionality.
A KCFI type identifier is a 32-bit constant produced by taking the
lower half of xxHash64 from a C++ mangled typename. If a program
contains indirect calls to assembly functions, they must be
manually annotated with the expected type identifiers to prevent
errors. To make this easier, Clang generates a weak SHN_ABS
`__kcfi_typeid_<function>` symbol for each address-taken function
declaration, which can be used to annotate functions in assembly
as long as at least one C translation unit linked into the program
takes the function address. For example on AArch64, we might have
the following code:
```
.c:
int f(void);
int (*p)(void) = f;
p();
.s:
.4byte __kcfi_typeid_f
.global f
f:
...
```
Note that X86 uses a different preamble format for compatibility
with Linux kernel tooling. See the comments in
`X86AsmPrinter::emitKCFITypeId` for details.
As users of KCFI may need to locate trap locations for binary
validation and error handling, LLVM can additionally emit the
locations of traps to a `.kcfi_traps` section.
Similarly to other sanitizers, KCFI checking can be disabled for a
function with a `no_sanitize("kcfi")` function attribute.
Relands 67504c9549 with a fix for
32-bit builds.
Reviewed By: nickdesaulniers, kees, joaomoreira, MaskRay
Differential Revision: https://reviews.llvm.org/D119296
The KCFI sanitizer, enabled with `-fsanitize=kcfi`, implements a
forward-edge control flow integrity scheme for indirect calls. It
uses a !kcfi_type metadata node to attach a type identifier for each
function and injects verification code before indirect calls.
Unlike the current CFI schemes implemented in LLVM, KCFI does not
require LTO, does not alter function references to point to a jump
table, and never breaks function address equality. KCFI is intended
to be used in low-level code, such as operating system kernels,
where the existing schemes can cause undue complications because
of the aforementioned properties. However, unlike the existing
schemes, KCFI is limited to validating only function pointers and is
not compatible with executable-only memory.
KCFI does not provide runtime support, but always traps when a
type mismatch is encountered. Users of the scheme are expected
to handle the trap. With `-fsanitize=kcfi`, Clang emits a `kcfi`
operand bundle to indirect calls, and LLVM lowers this to a
known architecture-specific sequence of instructions for each
callsite to make runtime patching easier for users who require this
functionality.
A KCFI type identifier is a 32-bit constant produced by taking the
lower half of xxHash64 from a C++ mangled typename. If a program
contains indirect calls to assembly functions, they must be
manually annotated with the expected type identifiers to prevent
errors. To make this easier, Clang generates a weak SHN_ABS
`__kcfi_typeid_<function>` symbol for each address-taken function
declaration, which can be used to annotate functions in assembly
as long as at least one C translation unit linked into the program
takes the function address. For example on AArch64, we might have
the following code:
```
.c:
int f(void);
int (*p)(void) = f;
p();
.s:
.4byte __kcfi_typeid_f
.global f
f:
...
```
Note that X86 uses a different preamble format for compatibility
with Linux kernel tooling. See the comments in
`X86AsmPrinter::emitKCFITypeId` for details.
As users of KCFI may need to locate trap locations for binary
validation and error handling, LLVM can additionally emit the
locations of traps to a `.kcfi_traps` section.
Similarly to other sanitizers, KCFI checking can be disabled for a
function with a `no_sanitize("kcfi")` function attribute.
Reviewed By: nickdesaulniers, kees, joaomoreira, MaskRay
Differential Revision: https://reviews.llvm.org/D119296
Allows things like `(G_PTR_ADD (G_PTR_ADD a, b), c)` to be
simplified into a single ADD3 instruction instead of two adds.
Reviewed By: foad
Differential Revision: https://reviews.llvm.org/D131254
While working on https://reviews.llvm.org/D131429, I got a test diff in
one of the VE tests and running update_llc_test_checks.py deleted all the
code for that function. This updates the regex to handle this new output.
Reviewed By: kaz7
Differential Revision: https://reviews.llvm.org/D131431
This commit moves the information on whether a register is constant into
the Tablegen files to allow generating the implementaiton of
isConstantPhysReg(). I've marked isConstantPhysReg() as final in this
generated file to ensure that changes are made to tablegen instead of
overriding this function, but if that turns out to be too restrictive,
we can remove the qualifier.
This should be pretty much NFC, but I did notice that e.g. the AMDGPU
generated file also includes the LO16/HI16 registers now.
The new isConstant flag will also be used by D131958 to ensure that
constant registers are marked as call-preserved.
Differential Revision: https://reviews.llvm.org/D131962
This allows reading arguments from file using the response file syntax.
We would like to use this in the LLVM build to pass test suites from
subbuilds.
Differential Revision: https://reviews.llvm.org/D132437
If a MachineInstr's operand should be Reg in compiler's output but is
currently FrameIndex, `isCompressibleInst()` will terminate at
`MachineOperandType::getReg()`.
This patch adds `.isReg()` checks to make `isCompressibleInst()` return
false for these MachineInstr, allowing `getInstSizeInBytes()` to return
a value and `EstimateFunctionSizeInBytes()` to work as intended.
See https://reviews.llvm.org/D129999#3694222 for details.
Reviewed By: luismarques
Differential Revision: https://reviews.llvm.org/D129999
When a type has a summary and synthetic child provider, the children are shown
only if `--expand`/`-e` is given.
This updates `lldbDataFormatters.py` to expand children of types that have both
a summary and synthetic children.
Differential Revision: https://reviews.llvm.org/D132095
We currently use CMake's find_library function to detect whether
libpthread exists on the system to determine if pthread should
be added on the link step. However, there are configurations in
which CMake's path checking fails to find the library even though
the toolchain has it.
One such case is with Clang 14.0.0 on PowerPC. Due to a recent
change, the build puts libc++ and related libraries in a
subdirectory that appears to depend on the default target triple.
CMake then uses that subdirectory to determine the architecture
and adds that name to its search paths. However, the triple for
the system GNU toolchain is different so CMake fails to find it.
Namely, Clang 14.0.0's default target triple and the subdirectory
name is powerpc64le-unknown-linux-gnu whereas the system GNU
toolchain has powerpc64le-linux-gnu. Clang's driver has no trouble
finding either the GNU includes/libraries or Clang's own. But
CMake seems to get this wrong.
The net result of this is that we can't do a shared libraries
build of ToT with Clang 14.0.0.
This patch proposes using HAVE_LIBPTHREAD which CMake seems to
determine by compiling a test file with -lpthread (or perhaps
-pthread, I can't really get CMake to tell me how it is figuring
this out). If that variable tells CMake that the build compiler
accepts the pthread option, it seems reasonable to depend on
that variable to determine if we should add it to the link step
when building the llvm_gtest library.
This patch removes llvm::is_trivially_copyable as it seems to be dead.
Once I remove it, HAVE_STD_IS_TRIVIALLY_COPYABLE has no users, so this
patch removes the macro also.
The comment on llvm::is_trivially_copyable mentions GCC 4.9, but note
that we now require GCC 7.1 or higher.
Differential Revision: https://reviews.llvm.org/D132328
Use this instead of `*_LIBDIR_SUFFIX`, from which it is computed.
This gets us ready for D130586, in which `*_LIBDIR_SUFFIX` is
deprecated.
Differential Revision: https://reviews.llvm.org/D132300
We held off on this before as `LLVM_LIBDIR_SUFFIX` conflicted with it.
Now we return this.
`LLVM_LIBDIR_SUFFIX` is kept as a deprecated way to set
`CMAKE_INSTALL_LIBDIR`. The other `*_LIBDIR_SUFFIX` are just removed
entirely.
I imagine this is too potentially-breaking to make LLVM 15. That's fine.
I have a more minimal version of this in the disto (NixOS) patches for
LLVM 15 (like previous versions). This more expansive version I will
test harder after the release is cut.
Reviewed By: sebastian-ne, ldionne, #libc, #libc_abi
Differential Revision: https://reviews.llvm.org/D130586
For now, this only builds the dylib, so using `-fsanitize=undefined`
with `-static-libsan` or `fsanitize-minimal-runtime` still won't
work -- but the common case does work.
Differential Revision: https://reviews.llvm.org/D131969
Add initial support for NonNull attribute.
(https://github.com/llvm/llvm-project/issues/57113)
Test plan:
verify that for
__thread int x;
int main() {
int* y = &x;
return *y;
}
(with this patch) clang -O -fsanitize=null -S -emit-llvm -o -
doesn't emit a null-pointer check
Differential revision: https://reviews.llvm.org/D131872
This fixes some fallout from D131282. Currently, add_tablegen() will add the tablegen target to LLVM_EXPORTS and associates the install with LLVMExports. For non-standalone builds, this means that you end up with mlir-tblgen and clang-tblgen in LLVMExports.
However, these projects should instead be using MLIR_EXPORTS/MLIRTargets and CLANG_EXPORTS/ClangTargets. To fix this, add an extra EXPORT option and make use of get_target_export_arg() to create the correct export argument.
Reviewed By: ashay-github
Differential Revision: https://reviews.llvm.org/D131565
Add a flag to enable BOLT. Should be used in x86-64 and
AArch64 linux builds only, since BOLT doesn't really support other
targets and is mostly tested on these two systems as hosts.
Reviewed By: tstellar
Differential Revision: https://reviews.llvm.org/D131703
It fittingly already makes use of add_llvm_utility during target creation and is usually only used in conjunction with other (test) related utilities such as FileCheck and not, which are already in utils.
Differential Revision: https://reviews.llvm.org/D131713
ARMAsmPrinter::emitFunctionEntryLabel() was not calling the base class
function so the $local alias was not being emitted. This should not have
any function effect right now since ARM does not generate different code
for the $local symbols, but it could be improved in the future.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D131392
Prior to this patch, the `add_tablegen()` macro in
llvm/cmake/modules/TableGen.cmake added the install rule only if
`project` matched `LLVM` or `MLIR`. This patch adds an optional
`DESTINATION` argument, which, if non-empty, decides whether (and where)
to install the tablegen tool, thus eliminating the need for
project-specific overrides. This patch also updates all other
invocations of the `add_tablegen()` macro.
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D131282
glibc annotates `process_vm_readv` with `__THROW`.
lldb/include/lldb/Host/linux/Uio.h and
lldb/source/Host/linux/LibcGlue.cpp don't.
Having a mismatch causes an error with c++17:
../../lldb/source/Host/linux/LibcGlue.cpp:18:9:
error: 'process_vm_readv' is missing exception specification 'throw()'
ssize_t process_vm_readv(::pid_t pid, const struct iovec *local_iov,
^
../../lldb/include/lldb/Host/linux/Uio.h:18:9:
note: previous declaration is here
ssize_t process_vm_readv(::pid_t pid, const struct iovec *local_iov,
^
The diagnostic is a bit misleading, since the previous declaration
in the sysroot (in usr/include/x76_64-linux-gnu/bits/uio-ext.h) is
what has the `__THROW`.
In the cmake build, cmake sets `HAVE_PROCESS_VM_READV` correctly based
on header probing.
In the GN build, just set it to 1 unconditionally on linux. If that
turns out to not be good enough everywhere, we'll have to add a GN arg
for this.
(I'm also setting it to 1 on Android. I'm not sure if that's correct --
but we don't build lldb for Android anyways.)
If you pass a NULL reivew ID to the differential.revision.search API,
it returns all revisions and we were just taking the first one and
assuming it was associated with the commit in the PR.
We need to exit early if we can't find a Phabricator review associated
with a commit.
When using AdditionalArguments in a GICombinerHelper, the generator
does not put a space between the type and the name.
E.g.
let AdditionalArguments = [GICombinerHelperArg<"bool", "IsSomething">];
ends up as
boolIsSomething) const;
in the generated file. This change adds a space between the type and the name.
Reviewed By: aemerson
Differential Revision: https://reviews.llvm.org/D130823
Rename it to clang-tidy-confusable-chars-gen, to make its role
clearer in a wider context.
In cross builds, the caller might want to provide this tool
externally (to avoid needing to rebuild it in the cross build).
In such a case, having the tool properly namespaced makes its role
clearer.
This matches how the clang-pseudo-gen tool was renamed in
a43fef05d4 / D126725.
Differential Revision: https://reviews.llvm.org/D129798
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