llvm-project.git/clang/test/OpenMP/target_enter_data_codegen.cpp, branch main

[IRBuilder] Generate nuw GEPs for struct member accesses (#99538)

2024-08-09T12:25:04+00:00

Generate nuw GEPs for struct member accesses, as inbounds + non-negative
implies nuw.

Regression tests are updated using update scripts where possible, and by
find + replace where not.

[OpenMP] Fix stack corruption due to argument mismatch (#96386)

2024-07-05T05:09:15+00:00

While lowering (#pragma omp target update from), clang's generated
.omp_task_entry. is setting up 9 arguments while calling
__tgt_target_data_update_nowait_mapper.

At the same time, in __tgt_target_data_update_nowait_mapper, call to
targetData() is converted to a sibcall assuming
it has the argument count listed in the signature.

AARCH64 asm sequence for this is as follows (removed unrelated insns):

`
.omp_task_entry..108:
  sub   sp, sp, #32
  stp   x29, x30, sp, #16       // 16-byte Folded Spill
  add   x29, sp, #16
  str   x8, sp, #8. // stack canary
  str   xzr, [sp]
  bl   __tgt_target_data_update_nowait_mapper

__tgt_target_data_update_nowait_mapper:
  sub   sp, sp, #32
  stp   x29, x30, sp, #16       // 16-byte Folded Spill
  add   x29, sp, #16
  str   x8, sp, #8 // stack canary
  // Sibcall argument setup
adrp x8,
:got:_Z16targetDataUpdateP7ident_tR8DeviceTyiPPvS4_PlS5_S4_S4_R11AsyncInfoTyb
ldr x8, [x8,
:got_lo12:_Z16targetDataUpdateP7ident_tR8DeviceTyiPPvS4_PlS5_S4_S4_R11AsyncInfoTyb]
  stp   x9, x8, x29, #16
  adrp  x8, .L.str.8
  add   x8, x8, :lo12:.L.str.8
  str   x8, x29, #32. <==. This is the insn that erases $fp

  ldp   x29, x30, sp, #16       // 16-byte Folded Reload
  add   sp, sp, #32
  // Sibcall
b
ZL10targetDataI22TaskAsyncInfoWrapperTyEvP7ident_tliPPvS4_PlS5_S4_S4_PFiS2_R8DeviceTyiS4_S4_S5_S5_S4_S4_R11AsyncInfoTybEPKcSD
`

On AArch64, call to __tgt_target_data_update_nowait_mapper in
.omp_task_entry. sets up only single space on stack and this results in
ovewriting $fp and subsequent stack corruption. This issue can be
credited to discrepancy of __tgt_target_data_update_nowait_mapper
signature in openmp/libomptarget/include/omptarget.h taking 13 arguments
while clang/lib/CodeGen/CGOpenMPRuntime.cpp and
llvm/include/llvm/Frontend/OpenMP/OMPKinds.def taking only 9 arguments.

This patch modifies __tgt_target_data_update_nowait_mapper signature to
match .omp_task_entry usage(and other 2 files mentioned above).

Co-authored-by: Kugan Vivekanandarajah

Diagnose use of VLAs in C++ by default

2023-10-20T17:10:03+00:00

Reapplication of 7339c0f782d5c70e0928f8991b0c05338a90c84c with a fix
for a crash involving arrays without a size expression.

Clang supports VLAs in C++ as an extension, but we currently only warn
on their use when you pass -Wvla, -Wvla-extension, or -pedantic.
However, VLAs as they're expressed in C have been considered by WG21
and rejected, are easy to use accidentally to the surprise of users
(e.g., https://ddanilov.me/default-non-standard-features/), and they
have potential security implications beyond constant-size arrays
(https://wiki.sei.cmu.edu/confluence/display/c/ARR32-C.+Ensure+size+arguments+for+variable+length+arrays+are+in+a+valid+range).
C++ users should strongly consider using other functionality such as
std::vector instead.

This seems like sufficiently compelling evidence to warn users about
VLA use by default in C++ modes. This patch enables the -Wvla-extension
diagnostic group in C++ language modes by default, and adds the warning
group to -Wall in GNU++ language modes. The warning is still opt-in in
C language modes, where support for VLAs is somewhat less surprising to
users.

RFC: https://discourse.llvm.org/t/rfc-diagnosing-use-of-vlas-in-c/73109
Fixes https://github.com/llvm/llvm-project/issues/62836
Differential Revision: https://reviews.llvm.org/D156565

Revert "Diagnose use of VLAs in C++ by default"

2023-10-20T14:00:18+00:00

This reverts commit 7339c0f782d5c70e0928f8991b0c05338a90c84c.

Breaks bots:
https://lab.llvm.org/buildbot/#/builders/139/builds/51875
https://lab.llvm.org/buildbot/#/builders/164/builds/45262

Diagnose use of VLAs in C++ by default

2023-10-20T13:50:21+00:00

Clang supports VLAs in C++ as an extension, but we currently only warn
on their use when you pass -Wvla, -Wvla-extension, or -pedantic.
However, VLAs as they're expressed in C have been considered by WG21
and rejected, are easy to use accidentally to the surprise of users
(e.g., https://ddanilov.me/default-non-standard-features/), and they
have potential security implications beyond constant-size arrays
(https://wiki.sei.cmu.edu/confluence/display/c/ARR32-C.+Ensure+size+arguments+for+variable+length+arrays+are+in+a+valid+range).
C++ users should strongly consider using other functionality such as
std::vector instead.

This seems like sufficiently compelling evidence to warn users about
VLA use by default in C++ modes. This patch enables the -Wvla-extension
diagnostic group in C++ language modes by default, and adds the warning
group to -Wall in GNU++ language modes. The warning is still opt-in in
C language modes, where support for VLAs is somewhat less surprising to
users.

RFC: https://discourse.llvm.org/t/rfc-diagnosing-use-of-vlas-in-c/73109
Fixes https://github.com/llvm/llvm-project/issues/62836
Differential Revision: https://reviews.llvm.org/D156565

[OpenMP][OMPIRBuilder] Rename IsEmbedded and IsTargetCodegen flags

2023-07-10T13:14:16+00:00

This patch renames the `OpenMPIRBuilderConfig` flags to reduce confusion over
their meaning. `IsTargetCodegen` becomes `IsGPU`, whereas `IsEmbedded` becomes
`IsTargetDevice`. The `-fopenmp-is-device` compiler option is also renamed to
`-fopenmp-is-target-device` and the `omp.is_device` MLIR attribute is renamed
to `omp.is_target_device`. Getters and setters of all these renamed properties
are also updated accordingly. Many unit tests have been updated to use the new
names, but an alias for the `-fopenmp-is-device` option is created so that
external programs do not stop working after the name change.

`IsGPU` is set when the target triple is AMDGCN or NVIDIA PTX, and it is only
valid if `IsTargetDevice` is specified as well. `IsTargetDevice` is set by the
`-fopenmp-is-target-device` compiler frontend option, which is only added to
the OpenMP device invocation for offloading-enabled programs.

Differential Revision: https://reviews.llvm.org/D154591

[OpenMP] Update the default version of OpenMP to 5.1

2023-06-15T07:11:09+00:00

The default version of OpenMP is updated from 5.0 to 5.1 which means if -fopenmp is specified but -fopenmp-version is not specified with clang, the default version of OpenMP is taken to be 5.1. After modifying the Frontend for that, various LIT tests were updated. This patch contains all such changes. At a high level, these are the patterns of changes observed in LIT tests -

# RUN lines which mentioned `-fopenmp-version=50` need to kept only if the IR for version 5.0 and 5.1 are different. Otherwise only one RUN line with no version info(i.e. default version) needs to be there.

# Test cases of this sort already had the RUN lines with respect to the older default version 5.0 and the version 5.1. Only swapping the version specification flag `-fopenmp-version` from newer version RUN line to older version RUN line is required.

# Diagnostics: Remove the 5.0 version specific RUN lines if there was no difference in the Diagnostics messages with respect to the default 5.1.

# Diagnostics: In case there was any difference in diagnostics messages between 5.0 and 5.1, mention version specific messages in tests.

# If the test contained version specific ifdef's e.g. "#ifdef OMP5" but there were no RUN lines for any other version than 5.X, then bring the code guarded by ifdef's outside and remove the ifdef's.

# Some tests had RUN lines for both 5.0 and 5.1 versions, but it is found that the IR for 5.0 is not different from the 5.1, therefore such RUN lines are redundant. So, such duplicated lines are removed.

# To generate CHECK lines automatically, use the script llvm/utils/update_cc_test_checks.py

Reviewed By: saiislam, ABataev

Differential Revision: https://reviews.llvm.org/D129635

(cherry picked from commit 9dd2999907dc791136a75238a6000f69bf67cf4e)

[clang] Convert remaining OpenMP tests to opaque pointers

2023-05-17T20:27:43+00:00

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D150733

[ConstExpr] Don't create div/rem expressions

2022-07-05T13:54:53+00:00

This removes creation of udiv/sdiv/urem/srem constant expressions,
in preparation for their removal. I've added a
ConstantExpr::isDesirableBinOp() predicate to determine whether
an expression should be created for a certain operator.

With this patch, div/rem expressions can still be created through
explicit IR/bitcode, forbidding them entirely will be the next step.

Differential Revision: https://reviews.llvm.org/D128820

[OpaquePtrs][Clang] Add -no-opaque-pointers to tests (NFC)

2022-04-07T10:09:47+00:00

This adds -no-opaque-pointers to clang tests whose output will
change when opaque pointers are enabled by default. This is
intended to be part of the migration approach described in
https://discourse.llvm.org/t/enabling-opaque-pointers-by-default/61322/9.

The patch has been produced by replacing %clang_cc1 with
%clang_cc1 -no-opaque-pointers for tests that fail with opaque
pointers enabled. Worth noting that this doesn't cover all tests,
there's a remaining ~40 tests not using %clang_cc1 that will need
a followup change.

Differential Revision: https://reviews.llvm.org/D123115