Ignore duplicated switch cases with [[fallthrough]] attribute to reduce false positives.

Fixes: #47588

Reviewed By: donat.nagy

Differential Revision: https://reviews.llvm.org/D147889

Reviewed By: fakepaper56

Differential Revision: https://reviews.llvm.org/D151132

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D151141

In `select c, x, y` the condition `c` dominates the resulting `x` or
`y` chosen by the `select`. This adds logic to `isKnownNonZero` to try
and use the `icmp` for the `c` condition to see if it implies the
select `x` or `y` are known non-zero.

For example in:
    ```
    %c = icmp ugt i8 %x, %C
    %r = select i1 %c, i8 %x, i8 %y
    ```
    The true arm of select `%x` is non-zero (when "returned" by the
    `select`) because `%c` being true implies `%x` is non-zero.

Alive2 Links (with `x {pred} C`):
    - EQ  iff `C != 0`:
        - https://alive2.llvm.org/ce/z/umLabn
    - NE  iff `C == 0`:
        - https://alive2.llvm.org/ce/z/DQvy8Y
    - UGT [always]:
        - https://alive2.llvm.org/ce/z/HBkjgQ
    - UGE iff `C != 0`:
        - https://alive2.llvm.org/ce/z/LDNifB
    - SGT iff `C s>= 0`:
        - https://alive2.llvm.org/ce/z/QzWDj3
    - SGE iff `C s> 0`:
        - https://alive2.llvm.org/ce/z/rR4g3D
    - SLT iff `C s<= 0`:
        - https://alive2.llvm.org/ce/z/uysayx
    - SLE iff `C s< 0`:
        - https://alive2.llvm.org/ce/z/2jYc7e

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D147900

Differential Revision: https://reviews.llvm.org/D147899

The knownbits implementation covers all the cases previously handled
by `uadd.sat`/`usub.sat` as well some additional ones. We previously
were not handling the `ssub.sat`/`sadd.sat` cases at all.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D150103

These where previously missing. Even in the case where overflow is
indeterminate we can still deduce some of the low/high bits.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D150102

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D150101

`abs` preserves the lowest set bit, so if we know the lowest set bit,
set it in the output.

As well, implement the case where the operand is known negative.

Reviewed By: foad, RKSimon

Differential Revision: https://reviews.llvm.org/D150100

Reported by Coverity static analyzer tool:

Inside "ItaniumCXXABI.cpp" file, in <unnamed>::ItaniumCXXABI::EmitLoadOfMemberFunctionPointer(clang::CodeGen::CodeGenFunction &, clang::Expr const *, clang::CodeGen::Address, llvm::Value *&, llvm::Value *, clang::MemberPointerType const *): Return value of function which returns null is dereferenced without checking.

   //returned_null: getAs returns nullptr (checked 130 out of 156 times).
   //var_assigned: Assigning: FPT = nullptr return value from getAs.
   const FunctionProtoType *FPT =
     MPT->getPointeeType()->getAs<FunctionProtoType>();
  auto *RD =
     cast<CXXRecordDecl>(MPT->getClass()->castAs<RecordType>()->getDecl());

  // Dereference null return value (NULL_RETURNS)
  //dereference: Dereferencing a pointer that might be nullptr FPT when calling arrangeCXXMethodType.
   llvm::FunctionType *FTy = CGM.getTypes().GetFunctionType(
       CGM.getTypes().arrangeCXXMethodType(RD, FPT, /*FD=*/nullptr));

This patch uses castAs instead of getAs which will assert if the type doesn't match.

Reviewed By: erichkeane

Differential Revision: https://reviews.llvm.org/D151054

This simple diff declares some enum values needed to create a REPL for the mojo language.

Differential Revision: https://reviews.llvm.org/D150303

Add minimal support to lower return, and introduce an OutgoingValueHandler and an OutgoingValueAssigner for returns.

Supports return values with integer, pointer and aggregate types.

(Update of D69808 - avoiding commandeering that revision)

Co-authored By: lewis-revill

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D117318

This patch does the bare minimum to import sanitizer_common_interceptors, but
without actually enabling any interceptors or meaningfully defining the
COMMON_INTERCEPT macros.

This will allow selectively enabling sanitizer_common interceptors (if the
appropriate macros are defined), as suggested by Vitaly in D149701.

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D150708

This fixes an issue with missing `unsigned long` conversion on macOS.

Reviewed By: michaelrj

Differential Revision: https://reviews.llvm.org/D151234

https://reviews.llvm.org/D150742 is the fix.

This reverts commit edd0981e.

Now with support for MSVC-specific triples.

CWG977 focus on point of /completeness/ of enums. Wording provided in CWG1482.
CWG1482 and CWG2516 focus on locus (point) of /declaration/. Wording provided in CWG2516.

Reviewed By: clang-language-wg, shafik

Differential Revision: https://reviews.llvm.org/D151042

2.9.0 was released on December 28, 2021, and some following changes
require at least this version.

Reviewed By: stellaraccident

Differential Revision: https://reviews.llvm.org/D150247

C++s iterator concept requires operator* to return the same type as is specified by the iterators reference type. This functionality is especially important for older generic code that did not yet make use of auto.
An example from within LLVM is iterator_adaptor_base which uses the reference type of the iterator it is wrapping as its return type for operator* (this class is used as base for a lot of other functionality like filter iterators and so on).
Using any of the graph traversal iterators listed above with it would previously fail to compile due to reference being non-const while operator* returned a const reference.

This patch fixes that by correctly specifying reference and using it as the return type of operator* explicitly to prevent further issues in the future.

Differential Revision: https://reviews.llvm.org/D151198

This will avoid hardcoding all unsupported targets, since even after one
more follow up fix [1], there is one more failure.

  [1]: https://reviews.llvm.org/D150886

Plus, if you want to run it locally on some target that CI does not
covers, it could also false-positively fail, which is not good.

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D151046

[lldb][NFCI] Merge implementations of ObjectFileMachO::GetMinimumOSVersion and ObjectFileMachO::GetSDKVersion

These functions do the exact same thing (even if they look slightly
different). I yanked the common implementation, cleaned it up, and
shoved it into its own function.

Differential Revision: https://reviews.llvm.org/D151120

This patch adds support to shape cast a vector<1x1x1...1xElemenType> to
a vector<ElementType> and the other way around.

Differential Revision: https://reviews.llvm.org/D151169

Summry:
This was accidentally dropped from a previous patch following a rebase.
Fix it to where it's consistent.

Differential Revision: https://reviews.llvm.org/D151232

We documented -fmsc-version as defaulting to 1300 and
-fms-compatibility-version as defaulting to 1800, neither of which
were accurate. We currently default to 1920.

See MSVCToolChain::computeMSVCVersion() for details.

Ensures a subsequent call (via an external caller) to
__sanitizer_get_allocated_size via hooks will return a valid size.

This allows a faster version of __sanitizer_get_allocated_size
to be implemented, which can skip checks.

Test to ensure RunFreeHooks' call order will come with
__sanitizer_get_allocated_size_fast

Differential Revision: https://reviews.llvm.org/D151151

This is a followup of the review comments in D144499.

Reviewed By: ldionne, philnik, #libc

Differential Revision: https://reviews.llvm.org/D150585

This member has been added in D148641 so it can be used in the formatter
to avoid creating a "temporary" string.

Reviewed By: #libc, ldionne

Differential Revision: https://reviews.llvm.org/D150791

This adds the cppm files of D144994. These files by themselves will do
nothing. The goal is to reduce the size of D144994 and making it easier
to review the real changes of the patch.

Implements parts of
- P2465R3 Standard Library Modules std and std.compat

Reviewed By: ldionne, ChuanqiXu, aaronmondal, #libc

Differential Revision: https://reviews.llvm.org/D151030

There are two motivations.

`-fno-pic -fstack-protector -mstack-protector-guard=global` created
`__stack_chk_guard` is referenced directly on all ELF OSes except FreeBSD.
This patch allows referencing the symbol indirectly with
-fno-direct-access-external-data.

Some Linux kernel folks want
`-fno-pic -fstack-protector -mstack-protector-guard-reg=gs -mstack-protector-guard-symbol=__stack_chk_guard`
created `__stack_chk_guard` to be referenced directly, avoiding
R_X86_64_REX_GOTPCRELX (even if the relocation may be optimized out by the linker).
https://github.com/llvm/llvm-project/issues/60116
Why they need this isn't so clear to me.

---

Add module flag "direct-access-external-data" and set the dso_local property of
the stack protector symbol. The module flag can benefit other LLVMCodeGen
synthesized symbols that are not represented in LLVM IR.

Nowadays, with `-fno-pic` being uncommon, ideally we should set
"direct-access-external-data" when it is true. However, doing so would require
~90 clang/test tests to be updated, which are too much.

As a compromise, we set "direct-access-external-data" only when it's different
from the implied default value.

Reviewed By: nickdesaulniers

Differential Revision: https://reviews.llvm.org/D150841

During the ISO C++ Committee meeting plenary session the C++23 Standard
has been voted as technical complete.

This updates the reference to c++2b to c++23 and updates the __cplusplus
macro.

Note since we use clang-tidy 16 a small work-around is needed. Clang
knows -std=c++23 but clang-tidy not so for now force the lit compiler
flag to use -std=c++2b instead of -std=c++23.

Reviewed By: #libc, philnik, jloser, ldionne

Differential Revision: https://reviews.llvm.org/D150795

Previously lsan would not invoke hooks on reallocations.
An accompanying regression test is included in sanitizer_common.

This change also moves hook calls to a location where subsequent
calls (via an external caller) to __sanitizer_get_allocated_size
via hooks will return a valid size.

This allows a faster version of __sanitizer_get_allocated_size
to be implemented, which can skip checks.

Test to ensure RunFreeHooks' call order will come with
__sanitizer_get_allocated_size_fast

Differential Revision: https://reviews.llvm.org/D151175

There are several observations regarding the copy-in/copy-out:
  * Actual argument associated with INTENT(OUT) dummy argument that
    requires finalization (7.5.6.3 p. 7) may be read by the finalization
    function, so a copy-in is required.
  * A temporary created for the copy-in/copy-out must be destroyed
    without finalization after the call (or after the corresponding copy-out),
    otherwise, memory leaks may occur.
  * The copy-out assignment must not perform finalization for the LHS.
  * The copy-out assignment from the temporary to the actual argument
    may or may not need to initialize the LHS.

This change-set introduces new runtime methods: CopyOutAssign and
DestroyWithoutFinalization. They are called by the compiler generated
code to match the behavior described above.

Reviewed By: jeanPerier

Differential Revision: https://reviews.llvm.org/D151135

Differential Revision: https://reviews.llvm.org/D151167

On AArch64 for function multiversioning target_version/target_clones
attributes should be used. The patch fixes the defect allowing target
attribute to cause multiversioning.

Differential Revision: https://reviews.llvm.org/D150867

[LegalizeTypes][ARM][AArch6][RISCV][VE][WebAssembly] Add special case for smin(X, -1) and smax(X, 0) to ExpandIntRes_MINMAX.

We can compute a simpler expression for Lo for these cases. This
is an alternative for the test cases in D151180 that works for
more targets.

This is similar to some of the special cases we have for expanding
setcc operands.

Differential Revision: https://reviews.llvm.org/D151182

These files aren't fully formatted. I'm guessing this was a holdover
from when `clang-format` was totally broken for OpenMP offloading.
Format the files to be more consistent.

Reviewed By: tianshilei1992

Differential Revision: https://reviews.llvm.org/D151226

Currently we have the `send_n` and `recv_n` routines to stream data,
such as a string to print, to the other side. The first operation is to
send the size so the other side knows the number of bytes to recieve.
However, this wasted 56 bytes that could've been sent. This meant that
small values, like the arguments to a function to call on the host for
example, needed to perform an extra send. This patch sends the first 56
bytes in the first packet and continues if necessary.

Depends on D150992

Reviewed By: JonChesterfield

Differential Revision: https://reviews.llvm.org/D151041

We provide the `send_n` and `recv_n` utilities as a generic way to
stream data between both sides of the process. This was previously
tested and performed as expected when using a string of constant size.
However, when the size was allowed to diverge between the threads in the
warp or wavefront this could deadlock. This did not occur on NVPTX
because of the use of the explicit warp sync. However, on AMD one of the
work items in the wavefront could continue executing and hit the next
`recv` call before the other threads, then we would deadlock as we
violated the RPC invariants.

This patch replaces the for loop with a thread ballot. This will cause
every thread in the warp or wavefront to continue executing the loop
until all of them can exit. This acts as a more explicit wavefront sync.

Reviewed By: JonChesterfield

Differential Revision: https://reviews.llvm.org/D150992

This also removes some tests which we have grouped together into robust_from_*.pass.cpp tests.

Specifically, checking that
- `ranges::dangling` is returned is done in `libcxx/test/std/algorithms/ranges_robust_against_dangling.pass.cpp`
- `std::invoke` is used is done in `libcxx/test/std/algorithms/ranges_robust_against_omitting_invoke.pass.cpp`.
- implicit conversion to bool works is done in `libcxx/test/std/algorithms/ranges_robust_against_nonbool_predicates.pass.cpp`

Checking the comparison order is invalid because the `operator==` isn't symmetric.
Checking what the exact type of `operator==` is, is invalid because comparing the same object has to yield the same results if the objects are not modified.

Reviewed By: ldionne, #libc

Spies: EricWF, libcxx-commits

Differential Revision: https://reviews.llvm.org/D150588