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@Naghasan Naghasan commented Feb 6, 2023

…ebuild

User can declare their type as device copyable even if they do not meet the criterias. In some cases,
this triggers calls to undefined, deleted or not allowed on device functions.

Per SYCL rules, a SYCL kernel object must be device copiable which implies the structure can be initialized using memcpy and have a trivial destructor. Plus the spec doesn't guarantee that the constructor/destructor should get called at all as it allows the functor to be reused by multiple WI.

This patch exploit that implementation defined behavior by preventing the constructor/destructor of being called by wrapping it into a union.

In order to prevent this, the SYCL kernel is wrapped into a union and instead of using initializer list,
the SYCL kernel clone is init using assignment for scalars, memcpy for non special types and Ctor/__init for SYCL special types.

Signed-off-by: Victor Lomuller [email protected]

…ebuild

User can declare their type as device copyable even
if they do not meet the criterias. In some cases,
this triggers calls to undefined, deleted or not allowed on device functions.

Per SYCL rules, a SYCL kernel object must be device copiable
which implies the structure can be initialized using memcpy
and have a trivial destructor. Plus the spec doesn't guarantee
that the constructor/destructor should get called at all as it allows the functor
to be reused by multiple WI.

This patch exploit that implementation defined behavior by preventing the constructor/destructor
of being called by wrapping it into a union.

In order to prevent this, the SYCL kernel is wrapped into a union and
instead of using initializer list,
the SYCL kernel clone is init using assignment for scalars, memcpy for non special types
and Ctor/__init for SYCL special types.

Signed-off-by: Victor Lomuller <[email protected]>
Naghasan pushed a commit that referenced this pull request Feb 6, 2023
In RegisterInfos_loongarch64.h, r22 is defined twice. Having an extra array
member causes problems reading and writing registers defined after r22. So,
for r22, keep the alias fp, delete the s9 alias.

The PC register is incorrectly accessed when the step command is executed.
The step command behavior is incorrect.

This test reflects this problem:

```
loongson@linux:~$ cat test.c

 #include <stdio.h>

int func(int a) {
  return a + 1;
}

int main(int argc, char const *argv[]) {
  func(10);
  return 0;
}

loongson@linux:~$ clang -g test.c  -o test

```

Without this patch:
```
loongson@linux:~$ llvm-project/llvm/build/bin/lldb test
(lldb) target create "test"
Current executable set to '/home/loongson/test' (loongarch64).
(lldb) b main
Breakpoint 1: where = test`main + 40 at test.c:8:3, address = 0x0000000120000668
(lldb) r
Process 278049 launched: '/home/loongson/test' (loongarch64)
Process 278049 stopped
* thread #1, name = 'test', stop reason = breakpoint 1.1
    frame #0: 0x0000000120000668 test`main(argc=1, argv=0x00007fffffff72a8) at test.c:8:3
   5   	}
   6
   7   	int main(int argc, char const *argv[]) {
-> 8   	  func(10);
   9   	  return 0;
   10  	}
   11
(lldb) s
Process 278049 stopped
* thread #1, name = 'test', stop reason = step in
    frame #0: 0x0000000120000670 test`main(argc=1, argv=0x00007fffffff72a8) at test.c:9:3
   6
   7   	int main(int argc, char const *argv[]) {
   8   	  func(10);
-> 9   	  return 0;
   10  	}

```

With this patch:

```
loongson@linux:~$ llvm-project/llvm/build/bin/lldb test
(lldb) target create "test"
Current executable set to '/home/loongson/test' (loongarch64).
(lldb) b main
Breakpoint 1: where = test`main + 40 at test.c:8:3, address = 0x0000000120000668
(lldb) r
Process 278632 launched: '/home/loongson/test' (loongarch64)
Process 278632 stopped
* thread #1, name = 'test', stop reason = breakpoint 1.1
    frame #0: 0x0000000120000668 test`main(argc=1, argv=0x00007fffffff72a8) at test.c:8:3
   5   	}
   6
   7   	int main(int argc, char const *argv[]) {
-> 8   	  func(10);
   9   	  return 0;
   10  	}
   11
(lldb) s
Process 278632 stopped
* thread #1, name = 'test', stop reason = step in
    frame #0: 0x0000000120000624 test`func(a=10) at test.c:4:10
   1   	 #include <stdio.h>
   2
   3   	int func(int a) {
-> 4   	  return a + 1;
   5   	}

```

Reviewed By: SixWeining, DavidSpickett

Differential Revision: https://reviews.llvm.org/D140615
Naghasan pushed a commit that referenced this pull request Feb 6, 2023
When building/testing ASan inside the GCC tree on Solaris while using GNU
`ld` instead of Solaris `ld`, a large number of tests SEGVs on both sparc
and x86 like this:

  Thread 2 received signal SIGSEGV, Segmentation fault.
  [Switching to Thread 1 (LWP 1)]
  0xfe014cfc in __sanitizer::atomic_load<__sanitizer::atomic_uintptr_t>
(a=0xfc602a58, mo=__sanitizer::memory_order_acquire) at
sanitizer_common/sanitizer_atomic_clang_x86.h:46
  46	      v = a->val_dont_use;
  1: x/i $pc
  => 0xfe014cfc
<_ZN11__sanitizer11atomic_loadINS_16atomic_uintptr_tEEENT_4TypeEPVKS2_NS_12memory_orderE+62>:
mov (%eax),%eax
  (gdb) bt
  #0 0xfe014cfc in __sanitizer::atomic_load<__sanitizer::atomic_uintptr_t>
(a=0xfc602a58, mo=__sanitizer::memory_order_acquire) at
sanitizer_common/sanitizer_atomic_clang_x86.h:46
  #1 0xfe0bd1d7 in __sanitizer::DTLS_NextBlock (cur=0xfc602a58) at
sanitizer_common/sanitizer_tls_get_addr.cpp:53
  intel#2 0xfe0bd319 in __sanitizer::DTLS_Find (id=1) at
sanitizer_common/sanitizer_tls_get_addr.cpp:77
  intel#3 0xfe0bd466 in __sanitizer::DTLS_on_tls_get_addr (arg_void=0xfeffd068,
res=0xfe602a18, static_tls_begin=0, static_tls_end=0) at
sanitizer_common/sanitizer_tls_get_addr.cpp:116
  intel#4 0xfe063f81 in __interceptor___tls_get_addr (arg=0xfeffd068) at
sanitizer_common/sanitizer_common_interceptors.inc:5501
  intel#5 0xfe0a3054 in __sanitizer::CollectStaticTlsBlocks (info=0xfeffd108,
size=40, data=0xfeffd16c) at
sanitizer_common/sanitizer_linux_libcdep.cpp:366
  intel#6  0xfe6ba9fa in dl_iterate_phdr () from /usr/lib/ld.so.1
  intel#7 0xfe0a3132 in __sanitizer::GetStaticTlsBoundary (addr=0xfe608020,
size=0xfeffd244, align=0xfeffd1b0) at
sanitizer_common/sanitizer_linux_libcdep.cpp:382
  intel#8 0xfe0a33f7 in __sanitizer::GetTls (addr=0xfe608020, size=0xfeffd244)
at sanitizer_common/sanitizer_linux_libcdep.cpp:482
  intel#9 0xfe0a34b1 in __sanitizer::GetThreadStackAndTls (main=true,
stk_addr=0xfe608010, stk_size=0xfeffd240, tls_addr=0xfe608020,
tls_size=0xfeffd244) at sanitizer_common/sanitizer_linux_libcdep.cpp:565

The address being accessed is unmapped.  However, even when the tests
`PASS` with Solaris `ld`, `ASAN_OPTIONS=verbosity=2` shows

  ==6582==__tls_get_addr: Can't guess glibc version

Given that that the code is stricly `glibc`-specific according to
`sanitizer_tls_get_addr.h`, there seems little point in using the
interceptor on non-`glibc` targets.

That's what this patch does.  Tested on `i386-pc-solaris2.11` and
`sparc-sun-solaris2.11` inside the GCC tree.

Differential Revision: https://reviews.llvm.org/D141385
Naghasan pushed a commit that referenced this pull request May 30, 2023
…est unittest

Need to finalize the DIBuilder to avoid leak sanitizer errors
like this:

Direct leak of 48 byte(s) in 1 object(s) allocated from:
    #0 0x55c99ea1761d in operator new(unsigned long)
    #1 0x55c9a518ae49 in operator new
    intel#2 0x55c9a518ae49 in llvm::MDTuple::getImpl(...)
    intel#3 0x55c9a4f1b1ec in getTemporary
    intel#4 0x55c9a4f1b1ec in llvm::DIBuilder::createFunction(...)
Naghasan pushed a commit that referenced this pull request Oct 9, 2023
Summary:
Thread sanitizer reports the following data race:

```
  Write of size 8 at 0x000103303e70 by thread T1 (mutexes: write M0):
    #0 RNBRemote::CommDataReceived(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>> const&) RNBRemote.cpp:1075 (debugserver:arm64+0x100038db8) (BuildId: f130b34f693c4f3eba96139104af2b7132000000200000000100000000000e00)
    #1 RNBRemote::ThreadFunctionReadRemoteData(void*) RNBRemote.cpp:1180 (debugserver:arm64+0x1000391dc) (BuildId: f130b34f693c4f3eba96139104af2b7132000000200000000100000000000e00)

  Previous read of size 8 at 0x000103303e70 by main thread:
    #0 RNBRemote::GetPacketPayload(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>&) RNBRemote.cpp:797 (debugserver:arm64+0x100037c5c) (BuildId: f130b34f693c4f3eba96139104af2b7132000000200000000100000000000e00)
    #1 RNBRemote::GetPacket(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>&, RNBRemote::Packet&, bool) RNBRemote.cpp:907 (debugserver:arm64+0x1000378cc) (BuildId: f130b34f693c4f3eba96139104af2b7132000000200000000100000000000e00)
```

RNBRemote already has a mutex, extend its usage to protect the read of
m_rx_packets.

Reviewers: jdevlieghere, bulbazord, jingham

Subscribers:
Naghasan pushed a commit that referenced this pull request Feb 15, 2024
…ass template explict specializations (#78720)

According to [[dcl.type.elab]
p2](http://eel.is/c++draft/dcl.type.elab#2):
> If an
[elaborated-type-specifier](http://eel.is/c++draft/dcl.type.elab#nt:elaborated-type-specifier)
is the sole constituent of a declaration, the declaration is ill-formed
unless it is an explicit specialization, an explicit instantiation or it
has one of the following forms [...]

Consider the following:
```cpp
template<typename T>
struct A 
{
    template<typename U>
    struct B;
};

template<>
template<typename U>
struct A<int>::B; // #1
```
The _elaborated-type-specifier_ at `#1` declares an explicit
specialization (which is itself a template). We currently (incorrectly)
reject this, and this PR fixes that.

I moved the point at which _elaborated-type-specifiers_ with
_nested-name-specifiers_ are diagnosed from `ParsedFreeStandingDeclSpec`
to `ActOnTag` for two reasons: `ActOnTag` isn't called for explicit
instantiations and partial/explicit specializations, and because it's
where we determine if a member specialization is being declared.

With respect to diagnostics, I am currently issuing the diagnostic
without marking the declaration as invalid or returning early, which
results in more diagnostics that I think is necessary. I would like
feedback regarding what the "correct" behavior should be here.
Naghasan pushed a commit that referenced this pull request Feb 15, 2024
…ing bound ops (#80317)

`getDataOperandBaseAddr` retrieve the address of a value when we need to
generate bound operations. When switching to HLFIR, we did not really
handle the fact that this value was then pointing to the result of a
hlfir.declare. Because of that the `#1` value was being used. `#0` value
is carrying the correct information about lowerbounds and should be
used. This patch updates the `getDataOperandBaseAddr` function to use
the correct result value from hlfir.declare.
Naghasan pushed a commit that referenced this pull request Feb 19, 2024
The concurrent tests all do a pthread_join at the end, and
concurrent_base.py stops after that pthread_join and sanity checks that
only 1 thread is running. On macOS, after pthread_join() has completed,
there can be an extra thread still running which is completing the
details of that task asynchronously; this causes testsuite failures.
When this happens, we see the second thread is in

```
frame #0: 0x0000000180ce7700 libsystem_kernel.dylib`__ulock_wake + 8
frame #1: 0x0000000180d25ad4 libsystem_pthread.dylib`_pthread_joiner_wake + 52
frame intel#2: 0x0000000180d23c18 libsystem_pthread.dylib`_pthread_terminate + 384
frame intel#3: 0x0000000180d23a98 libsystem_pthread.dylib`_pthread_terminate_invoke + 92
frame intel#4: 0x0000000180d26740 libsystem_pthread.dylib`_pthread_exit + 112
frame intel#5: 0x0000000180d26040 libsystem_pthread.dylib`_pthread_start + 148
```

there are none of the functions from the test file present on this
thread.

In this patch, instead of counting the number of threads, I iterate over
the threads looking for functions from our test file (by name) and only
count threads that have at least one of them.

It's a lower frequency failure than the darwin kernel bug causing an
extra step instruction mach exception when hardware
breakpoint/watchpoints are used, but once I fixed that, this came up as
the next most common failure for these tests.

rdar://110555062
Naghasan pushed a commit that referenced this pull request Feb 27, 2024
…(#80904)"

This reverts commit b1ac052.

This commit breaks coroutine splitting for non-swift calling convention
functions. In this example:

```ll
; ModuleID = 'repro.ll'
source_filename = "stdlib/test/runtime/test_llcl.mojo"
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

@0 = internal constant { i32, i32 } { i32 trunc (i64 sub (i64 ptrtoint (ptr @craSH to i64), i64 ptrtoint (ptr getelementptr inbounds ({ i32, i32 }, ptr @0, i32 0, i32 1) to i64)) to i32), i32 64 }

define dso_local void @af_suspend_fn(ptr %0, i64 %1, ptr %2) #0 {
  ret void
}

define dso_local void @craSH(ptr %0) #0 {
  %2 = call token @llvm.coro.id.async(i32 64, i32 8, i32 0, ptr @0)
  %3 = call ptr @llvm.coro.begin(token %2, ptr null)
  %4 = getelementptr inbounds { ptr, { ptr, ptr }, i64, { ptr, i1 }, i64, i64 }, ptr poison, i32 0, i32 0
  %5 = call ptr @llvm.coro.async.resume()
  store ptr %5, ptr %4, align 8
  %6 = call { ptr, ptr, ptr } (i32, ptr, ptr, ...) @llvm.coro.suspend.async.sl_p0p0p0s(i32 0, ptr %5, ptr @ctxt_proj_fn, ptr @af_suspend_fn, ptr poison, i64 -1, ptr poison)
  ret void
}

define dso_local ptr @ctxt_proj_fn(ptr %0) #0 {
  ret ptr %0
}

; Function Attrs: nomerge nounwind
declare { ptr, ptr, ptr } @llvm.coro.suspend.async.sl_p0p0p0s(i32, ptr, ptr, ...) #1

; Function Attrs: nounwind
declare token @llvm.coro.id.async(i32, i32, i32, ptr) intel#2

; Function Attrs: nounwind
declare ptr @llvm.coro.begin(token, ptr writeonly) intel#2

; Function Attrs: nomerge nounwind
declare ptr @llvm.coro.async.resume() #1

attributes #0 = { "target-features"="+adx,+aes,+avx,+avx2,+bmi,+bmi2,+clflushopt,+clwb,+clzero,+crc32,+cx16,+cx8,+f16c,+fma,+fsgsbase,+fxsr,+invpcid,+lzcnt,+mmx,+movbe,+mwaitx,+pclmul,+pku,+popcnt,+prfchw,+rdpid,+rdpru,+rdrnd,+rdseed,+sahf,+sha,+sse,+sse2,+sse3,+sse4.1,+sse4.2,+sse4a,+ssse3,+vaes,+vpclmulqdq,+wbnoinvd,+x87,+xsave,+xsavec,+xsaveopt,+xsaves" }
attributes #1 = { nomerge nounwind }
attributes intel#2 = { nounwind }
```

This verifier crashes after the `coro-split` pass with

```
cannot guarantee tail call due to mismatched parameter counts
  musttail call void @af_suspend_fn(ptr poison, i64 -1, ptr poison)
LLVM ERROR: Broken function
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.      Program arguments: opt ../../../reduced.ll -O0
 #0 0x00007f1d89645c0e __interceptor_backtrace.part.0 /build/gcc-11-XeT9lY/gcc-11-11.4.0/build/x86_64-linux-gnu/libsanitizer/asan/../../../../src/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:4193:28
 #1 0x0000556d94d254f7 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) /home/ubuntu/modular/third-party/llvm-project/llvm/lib/Support/Unix/Signals.inc:723:22
 intel#2 0x0000556d94d19a2f llvm::sys::RunSignalHandlers() /home/ubuntu/modular/third-party/llvm-project/llvm/lib/Support/Signals.cpp:105:20
 intel#3 0x0000556d94d1aa42 SignalHandler(int) /home/ubuntu/modular/third-party/llvm-project/llvm/lib/Support/Unix/Signals.inc:371:36
 intel#4 0x00007f1d88e42520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 intel#5 0x00007f1d88e969fc __pthread_kill_implementation ./nptl/pthread_kill.c:44:76
 intel#6 0x00007f1d88e969fc __pthread_kill_internal ./nptl/pthread_kill.c:78:10
 intel#7 0x00007f1d88e969fc pthread_kill ./nptl/pthread_kill.c:89:10
 intel#8 0x00007f1d88e42476 gsignal ./signal/../sysdeps/posix/raise.c:27:6
 intel#9 0x00007f1d88e287f3 abort ./stdlib/abort.c:81:7
 intel#10 0x0000556d8944be01 std::vector<llvm::json::Value, std::allocator<llvm::json::Value>>::size() const /usr/include/c++/11/bits/stl_vector.h:919:40
 intel#11 0x0000556d8944be01 bool std::operator==<llvm::json::Value, std::allocator<llvm::json::Value>>(std::vector<llvm::json::Value, std::allocator<llvm::json::Value>> const&, std::vector<llvm::json::Value, std::allocator<llvm::json::Value>> const&) /usr/include/c++/11/bits/stl_vector.h:1893:23
 intel#12 0x0000556d8944be01 llvm::json::operator==(llvm::json::Array const&, llvm::json::Array const&) /home/ubuntu/modular/third-party/llvm-project/llvm/include/llvm/Support/JSON.h:572:69
 intel#13 0x0000556d8944be01 llvm::json::operator==(llvm::json::Value const&, llvm::json::Value const&) (.cold) /home/ubuntu/modular/third-party/llvm-project/llvm/lib/Support/JSON.cpp:204:28
 intel#14 0x0000556d949ed2bd llvm::report_fatal_error(char const*, bool) /home/ubuntu/modular/third-party/llvm-project/llvm/lib/Support/ErrorHandling.cpp:82:70
 intel#15 0x0000556d8e37e876 llvm::SmallVectorBase<unsigned int>::size() const /home/ubuntu/modular/third-party/llvm-project/llvm/include/llvm/ADT/SmallVector.h:91:32
 intel#16 0x0000556d8e37e876 llvm::SmallVectorTemplateCommon<llvm::DiagnosticInfoOptimizationBase::Argument, void>::end() /home/ubuntu/modular/third-party/llvm-project/llvm/include/llvm/ADT/SmallVector.h:282:41
 intel#17 0x0000556d8e37e876 llvm::SmallVector<llvm::DiagnosticInfoOptimizationBase::Argument, 4u>::~SmallVector() /home/ubuntu/modular/third-party/llvm-project/llvm/include/llvm/ADT/SmallVector.h:1215:24
 intel#18 0x0000556d8e37e876 llvm::DiagnosticInfoOptimizationBase::~DiagnosticInfoOptimizationBase() /home/ubuntu/modular/third-party/llvm-project/llvm/include/llvm/IR/DiagnosticInfo.h:413:7
 intel#19 0x0000556d8e37e876 llvm::DiagnosticInfoIROptimization::~DiagnosticInfoIROptimization() /home/ubuntu/modular/third-party/llvm-project/llvm/include/llvm/IR/DiagnosticInfo.h:622:7
 intel#20 0x0000556d8e37e876 llvm::OptimizationRemark::~OptimizationRemark() /home/ubuntu/modular/third-party/llvm-project/llvm/include/llvm/IR/DiagnosticInfo.h:689:7
 intel#21 0x0000556d8e37e876 operator() /home/ubuntu/modular/third-party/llvm-project/llvm/lib/Transforms/Coroutines/CoroSplit.cpp:2213:14
 intel#22 0x0000556d8e37e876 emit<llvm::CoroSplitPass::run(llvm::LazyCallGraph::SCC&, llvm::CGSCCAnalysisManager&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&)::<lambda()> > /home/ubuntu/modular/third-party/llvm-project/llvm/include/llvm/Analysis/OptimizationRemarkEmitter.h:83:12
 intel#23 0x0000556d8e37e876 llvm::CoroSplitPass::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) /home/ubuntu/modular/third-party/llvm-project/llvm/lib/Transforms/Coroutines/CoroSplit.cpp:2212:13
 intel#24 0x0000556d8c36ecb1 llvm::detail::PassModel<llvm::LazyCallGraph::SCC, llvm::CoroSplitPass, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) /home/ubuntu/modular/third-party/llvm-project/llvm/include/llvm/IR/PassManagerInternal.h:91:3
 intel#25 0x0000556d91c1a84f llvm::PassManager<llvm::LazyCallGraph::SCC, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) /home/ubuntu/modular/third-party/llvm-project/llvm/lib/Analysis/CGSCCPassManager.cpp:90:12
 intel#26 0x0000556d8c3690d1 llvm::detail::PassModel<llvm::LazyCallGraph::SCC, llvm::PassManager<llvm::LazyCallGraph::SCC, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) /home/ubuntu/modular/third-party/llvm-project/llvm/include/llvm/IR/PassManagerInternal.h:91:3
 intel#27 0x0000556d91c2162d llvm::ModuleToPostOrderCGSCCPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) /home/ubuntu/modular/third-party/llvm-project/llvm/lib/Analysis/CGSCCPassManager.cpp:278:18
 intel#28 0x0000556d8c369035 llvm::detail::PassModel<llvm::Module, llvm::ModuleToPostOrderCGSCCPassAdaptor, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) /home/ubuntu/modular/third-party/llvm-project/llvm/include/llvm/IR/PassManagerInternal.h:91:3
 intel#29 0x0000556d9457abc5 llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) /home/ubuntu/modular/third-party/llvm-project/llvm/include/llvm/IR/PassManager.h:247:20
 intel#30 0x0000556d8e30979e llvm::CoroConditionalWrapper::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) /home/ubuntu/modular/third-party/llvm-project/llvm/lib/Transforms/Coroutines/CoroConditionalWrapper.cpp:19:74
 intel#31 0x0000556d8c365755 llvm::detail::PassModel<llvm::Module, llvm::CoroConditionalWrapper, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) /home/ubuntu/modular/third-party/llvm-project/llvm/include/llvm/IR/PassManagerInternal.h:91:3
 intel#32 0x0000556d9457abc5 llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) /home/ubuntu/modular/third-party/llvm-project/llvm/include/llvm/IR/PassManager.h:247:20
 intel#33 0x0000556d89818556 llvm::SmallPtrSetImplBase::isSmall() const /home/ubuntu/modular/third-party/llvm-project/llvm/include/llvm/ADT/SmallPtrSet.h:196:33
 intel#34 0x0000556d89818556 llvm::SmallPtrSetImplBase::~SmallPtrSetImplBase() /home/ubuntu/modular/third-party/llvm-project/llvm/include/llvm/ADT/SmallPtrSet.h:84:17
 intel#35 0x0000556d89818556 llvm::SmallPtrSetImpl<llvm::AnalysisKey*>::~SmallPtrSetImpl() /home/ubuntu/modular/third-party/llvm-project/llvm/include/llvm/ADT/SmallPtrSet.h:321:7
 intel#36 0x0000556d89818556 llvm::SmallPtrSet<llvm::AnalysisKey*, 2u>::~SmallPtrSet() /home/ubuntu/modular/third-party/llvm-project/llvm/include/llvm/ADT/SmallPtrSet.h:427:7
 intel#37 0x0000556d89818556 llvm::PreservedAnalyses::~PreservedAnalyses() /home/ubuntu/modular/third-party/llvm-project/llvm/include/llvm/IR/Analysis.h:109:7
 intel#38 0x0000556d89818556 llvm::runPassPipeline(llvm::StringRef, llvm::Module&, llvm::TargetMachine*, llvm::TargetLibraryInfoImpl*, llvm::ToolOutputFile*, llvm::ToolOutputFile*, llvm::ToolOutputFile*, llvm::StringRef, llvm::ArrayRef<llvm::PassPlugin>, llvm::ArrayRef<std::function<void (llvm::PassBuilder&)>>, llvm::opt_tool::OutputKind, llvm::opt_tool::VerifierKind, bool, bool, bool, bool, bool, bool, bool) /home/ubuntu/modular/third-party/llvm-project/llvm/tools/opt/NewPMDriver.cpp:532:10
 intel#39 0x0000556d897e3939 optMain /home/ubuntu/modular/third-party/llvm-project/llvm/tools/opt/optdriver.cpp:737:27
 intel#40 0x0000556d89455461 main /home/ubuntu/modular/third-party/llvm-project/llvm/tools/opt/opt.cpp:25:33
 intel#41 0x00007f1d88e29d90 __libc_start_call_main ./csu/../sysdeps/nptl/libc_start_call_main.h:58:16
 intel#42 0x00007f1d88e29e40 call_init ./csu/../csu/libc-start.c:128:20
 intel#43 0x00007f1d88e29e40 __libc_start_main ./csu/../csu/libc-start.c:379:5
 intel#44 0x0000556d897b6335 _start (/home/ubuntu/modular/.derived/third-party/llvm-project/build-relwithdebinfo-asan/bin/opt+0x150c335)
Aborted (core dumped)
Naghasan pushed a commit that referenced this pull request Jul 3, 2024
…erSize (#67657)"

This reverts commit f0b3654.

This commit triggers UB by reading an uninitialized variable.

`UP.PartialThreshold` is used uninitialized in `getUnrollingPreferences()` when
it is called from `LoopVectorizationPlanner::executePlan()`. In this case the
`UP` variable is created on the stack and its fields are not initialized.

```
==8802==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x557c0b081b99 in llvm::BasicTTIImplBase<llvm::X86TTIImpl>::getUnrollingPreferences(llvm::Loop*, llvm::ScalarEvolution&, llvm::TargetTransformInfo::UnrollingPreferences&, llvm::OptimizationRemarkEmitter*) llvm-project/llvm/include/llvm/CodeGen/BasicTTIImpl.h
    #1 0x557c0b07a40c in llvm::TargetTransformInfo::Model<llvm::X86TTIImpl>::getUnrollingPreferences(llvm::Loop*, llvm::ScalarEvolution&, llvm::TargetTransformInfo::UnrollingPreferences&, llvm::OptimizationRemarkEmitter*) llvm-project/llvm/include/llvm/Analysis/TargetTransformInfo.h:2277:17
    intel#2 0x557c0f5d69ee in llvm::TargetTransformInfo::getUnrollingPreferences(llvm::Loop*, llvm::ScalarEvolution&, llvm::TargetTransformInfo::UnrollingPreferences&, llvm::OptimizationRemarkEmitter*) const llvm-project/llvm/lib/Analysis/TargetTransformInfo.cpp:387:19
    intel#3 0x557c0e6b96a0 in llvm::LoopVectorizationPlanner::executePlan(llvm::ElementCount, unsigned int, llvm::VPlan&, llvm::InnerLoopVectorizer&, llvm::DominatorTree*, bool, llvm::DenseMap<llvm::SCEV const*, llvm::Value*, llvm::DenseMapInfo<llvm::SCEV const*, void>, llvm::detail::DenseMapPair<llvm::SCEV const*, llvm::Value*>> const*) llvm-project/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:7624:7
    intel#4 0x557c0e6e4b63 in llvm::LoopVectorizePass::processLoop(llvm::Loop*) llvm-project/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:10253:13
    intel#5 0x557c0e6f2429 in llvm::LoopVectorizePass::runImpl(llvm::Function&, llvm::ScalarEvolution&, llvm::LoopInfo&, llvm::TargetTransformInfo&, llvm::DominatorTree&, llvm::BlockFrequencyInfo*, llvm::TargetLibraryInfo*, llvm::DemandedBits&, llvm::AssumptionCache&, llvm::LoopAccessInfoManager&, llvm::OptimizationRemarkEmitter&, llvm::ProfileSummaryInfo*) llvm-project/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:10344:30
    intel#6 0x557c0e6f2f97 in llvm::LoopVectorizePass::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) llvm-project/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:10383:9

[...]

  Uninitialized value was created by an allocation of 'UP' in the stack frame
    #0 0x557c0e6b961e in llvm::LoopVectorizationPlanner::executePlan(llvm::ElementCount, unsigned int, llvm::VPlan&, llvm::InnerLoopVectorizer&, llvm::DominatorTree*, bool, llvm::DenseMap<llvm::SCEV const*, llvm::Value*, llvm::DenseMapInfo<llvm::SCEV const*, void>, llvm::detail::DenseMapPair<llvm::SCEV const*, llvm::Value*>> const*) llvm-project/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:7623:3
```
Naghasan pushed a commit that referenced this pull request Jul 3, 2024
…0820)

This solves some ambuguity introduced in P0522 regarding how
template template parameters are partially ordered, and should reduce
the negative impact of enabling `-frelaxed-template-template-args`
by default.

When performing template argument deduction, a template template
parameter
containing no packs should be more specialized than one that does.

Given the following example:
```C++
template<class T2> struct A;
template<template<class ...T3s> class TT1, class T4> struct A<TT1<T4>>; // #1
template<template<class    T5 > class TT2, class T6> struct A<TT2<T6>>; // intel#2

template<class T1> struct B;
template struct A<B<char>>;
```

Prior to P0522, candidate `intel#2` would be more specialized.
After P0522, neither is more specialized, so this becomes ambiguous.
With this change, `intel#2` becomes more specialized again,
maintaining compatibility with pre-P0522 implementations.

The problem is that in P0522, candidates are at least as specialized
when matching packs to fixed-size lists both ways, whereas before,
a fixed-size list is more specialized.

This patch keeps the original behavior when checking template arguments
outside deduction, but restores this aspect of pre-P0522 matching
during deduction.

---

Since this changes provisional implementation of CWG2398 which has
not been released yet, and already contains a changelog entry,
we don't provide a changelog entry here.
Naghasan pushed a commit that referenced this pull request Jul 3, 2024
… (#92855)

This solves some ambuguity introduced in P0522 regarding how template
template parameters are partially ordered, and should reduce the
negative impact of enabling `-frelaxed-template-template-args` by
default.

When performing template argument deduction, we extend the provisional
wording introduced in llvm/llvm-project#89807 so
it also covers deduction of class templates.

Given the following example:
```C++
template <class T1, class T2 = float> struct A;
template <class T3> struct B;

template <template <class T4> class TT1, class T5> struct B<TT1<T5>>;   // #1
template <class T6, class T7>                      struct B<A<T6, T7>>; // intel#2

template struct B<A<int>>;
```
Prior to P0522, `intel#2` was picked. Afterwards, this became ambiguous. This
patch restores the pre-P0522 behavior, `intel#2` is picked again.

This has the beneficial side effect of making the following code valid:
```C++
template<class T, class U> struct A {};
A<int, float> v;
template<template<class> class TT> void f(TT<int>);

// OK: TT picks 'float' as the default argument for the second parameter.
void g() { f(v); }
```

---

Since this changes provisional implementation of CWG2398 which has not
been released yet, and already contains a changelog entry, we don't
provide a changelog entry here.
Naghasan pushed a commit that referenced this pull request Jul 3, 2024
The problematic program is as follows:

```shell
#define pre_a 0
#define PRE(x) pre_##x

void f(void) {
    PRE(a) && 0;
}

int main(void) { return 0; }
```

in which after token concatenation (`##`), there's another nested macro
`pre_a`.

Currently only the outer expansion region will be produced. ([compiler
explorer
link](https://godbolt.org/#g:!((g:!((g:!((h:codeEditor,i:(filename:'1',fontScale:14,fontUsePx:'0',j:1,lang:___c,selection:(endColumn:29,endLineNumber:8,positionColumn:29,positionLineNumber:8,selectionStartColumn:29,selectionStartLineNumber:8,startColumn:29,startLineNumber:8),source:'%23define+pre_a+0%0A%23define+PRE(x)+pre_%23%23x%0A%0Avoid+f(void)+%7B%0A++++PRE(a)+%26%26+0%3B%0A%7D%0A%0Aint+main(void)+%7B+return+0%3B+%7D'),l:'5',n:'0',o:'C+source+%231',t:'0')),k:51.69491525423727,l:'4',n:'0',o:'',s:0,t:'0'),(g:!((g:!((h:compiler,i:(compiler:cclang_assertions_trunk,filters:(b:'0',binary:'1',binaryObject:'1',commentOnly:'0',debugCalls:'1',demangle:'0',directives:'0',execute:'0',intel:'0',libraryCode:'1',trim:'1',verboseDemangling:'0'),flagsViewOpen:'1',fontScale:14,fontUsePx:'0',j:2,lang:___c,libs:!(),options:'-fprofile-instr-generate+-fcoverage-mapping+-fcoverage-mcdc+-Xclang+-dump-coverage-mapping+',overrides:!(),selection:(endColumn:1,endLineNumber:1,positionColumn:1,positionLineNumber:1,selectionStartColumn:1,selectionStartLineNumber:1,startColumn:1,startLineNumber:1),source:1),l:'5',n:'0',o:'+x86-64+clang+(assertions+trunk)+(Editor+%231)',t:'0')),k:34.5741843594503,l:'4',m:28.903654485049834,n:'0',o:'',s:0,t:'0'),(g:!((h:output,i:(compilerName:'x86-64+clang+(trunk)',editorid:1,fontScale:14,fontUsePx:'0',j:2,wrap:'1'),l:'5',n:'0',o:'Output+of+x86-64+clang+(assertions+trunk)+(Compiler+%232)',t:'0')),header:(),l:'4',m:71.09634551495017,n:'0',o:'',s:0,t:'0')),k:48.30508474576271,l:'3',n:'0',o:'',t:'0')),l:'2',m:100,n:'0',o:'',t:'0')),version:4))

```text
f:
  File 0, 4:14 -> 6:2 = #0
  Decision,File 0, 5:5 -> 5:16 = M:0, C:2
  Expansion,File 0, 5:5 -> 5:8 = #0 (Expanded file = 1)
  File 0, 5:15 -> 5:16 = #1
  Branch,File 0, 5:15 -> 5:16 = 0, 0 [2,0,0] 
  File 1, 2:16 -> 2:23 = #0
  File 2, 1:15 -> 1:16 = #0
  File 2, 1:15 -> 1:16 = #0
  Branch,File 2, 1:15 -> 1:16 = 0, 0 [1,2,0] 
```

The inner expansion region isn't produced because:

1. In the range-based for loop quoted below, each sloc is processed and
possibly emit a corresponding expansion region.
2. For our sloc in question, its direct parent returned by
`getIncludeOrExpansionLoc()` is a `<scratch space>`, because that's how
`##` is processed.


https://github.com/llvm/llvm-project/blob/88b6186af3908c55b357858eb348b5143f21c289/clang/lib/CodeGen/CoverageMappingGen.cpp#L518-L520

3. This `<scratch space>` cannot be found in the FileID mapping so
`ParentFileID` will be assigned an `std::nullopt`


https://github.com/llvm/llvm-project/blob/88b6186af3908c55b357858eb348b5143f21c289/clang/lib/CodeGen/CoverageMappingGen.cpp#L521-L526

4. As a result this iteration of for loop finishes early and no
expansion region is added for the sloc.

This problem gets worse with MC/DC: as the example shows, there's a
branch from File 2 but File 2 itself is missing. This will trigger
assertion failures.

The fix is more or less a workaround and takes a similar approach as
#89573.

~~Depends on #89573.~~ This includes #89573. Kudos to @chapuni!
This and #89573 together fix #87000: I tested locally, both the reduced
program and my original use case (fwiw, Linux kernel) can run
successfully.

---------

Co-authored-by: NAKAMURA Takumi <[email protected]>
Naghasan pushed a commit that referenced this pull request Jul 3, 2024
…intel#13999)

Example `sycl-ls --verbose` output:

```
...
Platform [#1]:
    Version  : 1.3
    Name     : Intel(R) Level-Zero
    Vendor   : Intel(R) Corporation
    Devices  : 1
        Type              : gpu
        Version           : 12.60.7
        Name              : Intel(R) Data Center GPU Max 1550
        Vendor            : Intel(R) Corporation
        Driver            : 1.3.26918
        UUID              : 1341282141147000580000000
        Num SubDevices    : 2
        Num SubSubDevices : 8
        Aspects           : gpu fp16 fp64 ...
```
Naghasan pushed a commit that referenced this pull request Dec 4, 2024
When compiling for an SVE target we can use INDEX to generate constant
fixed-length step vectors, e.g.:
```
uint32x4_t foo() {
  return (uint32x4_t){0, 1, 2, 3};
}
```
Currently:
```
foo():
        adrp    x8, .LCPI1_0
        ldr     q0, [x8, :lo12:.LCPI1_0]
        ret
```
With INDEX:
```
foo():
        index   z0.s, #0, #1
        ret
```

The logic for this was already in `LowerBUILD_VECTOR`, though it was
hidden under a check for `!Subtarget->isNeonAvailable()`. This patch
refactors this to enable the corresponding code path unconditionally for
constant step vectors (as long as we can use SVE for them).
Naghasan pushed a commit that referenced this pull request Dec 4, 2024
…ates explicitly specialized for an implicitly instantiated class template specialization (#113464)

Consider the following:
```
template<typename T>
struct A {
  template<typename U>
  struct B {
    static constexpr int x = 0; // #1
  };

  template<typename U>
  struct B<U*> {
    static constexpr int x = 1; // intel#2
  };
};

template<>
template<typename U>
struct A<long>::B {
  static constexpr int x = 2; // intel#3
};

static_assert(A<short>::B<int>::y == 0); // uses #1
static_assert(A<short>::B<int*>::y == 1); // uses intel#2

static_assert(A<long>::B<int>::y == 2); // uses intel#3
static_assert(A<long>::B<int*>::y == 2); // uses intel#3
```

According to [temp.spec.partial.member] p2:
> If the primary member template is explicitly specialized for a given
(implicit) specialization of the enclosing class template, the partial
specializations of the member template are ignored for this
specialization of the enclosing class template.
If a partial specialization of the member template is explicitly
specialized for a given (implicit) specialization of the enclosing class
template, the primary member template and its other partial
specializations are still considered for this specialization of the
enclosing class template.

The example above fails to compile because we currently don't implement
[temp.spec.partial.member] p2. This patch implements the wording, fixing #51051.
Naghasan pushed a commit that referenced this pull request Dec 4, 2024
We've found that basic profiling could help improving/optimizing when
developing clang-tidy checks.

This PR adds an extra command
```
set enable-profile (true|false)   Set whether to enable matcher profiling.
```
which enables profiling queries on each file.

Sample output:

```
$ cat test.cql
set enable-profile true
m binaryOperator(isExpansionInMainFile())

$ cat test.c
int test(int i, int j) {
  return i + j;
}

$ clang-query --track-memory -f test.cql test.c --

Match #1:

{{.*}}/test.c:2:10: note: "root" binds here
    2 |   return i + j;
      |          ^~~~~
1 match.
===-------------------------------------------------------------------------===
                         clang-query matcher profiling
===-------------------------------------------------------------------------===
  Total Execution Time: 0.0000 seconds (0.0000 wall clock)

   ---User Time---   --System Time--   --User+System--   ---Wall Time---  ---Mem---  --- Name ---
   0.0000 (100.0%)   0.0000 (100.0%)   0.0000 (100.0%)   0.0000 (100.0%)        224  {{.*}}/test.c
   0.0000 (100.0%)   0.0000 (100.0%)   0.0000 (100.0%)   0.0000 (100.0%)        224  Total
```
Naghasan pushed a commit that referenced this pull request Jan 15, 2025
According to the documentation described at
https://github.com/loongson/la-abi-specs/blob/release/ladwarf.adoc, the
dwarf numbers for floating-point registers range from 32 to 63.

An incorrect dwarf number will prevent the register values from being
properly restored during unwinding.

This test reflects this problem:

```
loongson@linux:~$ cat test.c

void foo() {
  asm volatile ("movgr2fr.d $fs2, $ra":::"$fs2");
}
int main() {
  asm volatile ("movgr2fr.d $fs2, $sp":::"$fs2");
  foo();
  return 0;
}

loongson@linux:~$ clang -g test.c  -o test

```
Without this patch:
```
loongson@linux:~$ ./_build/bin/lldb ./t
(lldb) target create "./t"
Current executable set to
'/home/loongson/llvm-project/_build_lldb/t' (loongarch64).
(lldb) b foo
Breakpoint 1: where = t`foo + 20 at test.c:4:1, address =
0x0000000000000714
(lldb) r
Process 2455626 launched: '/home/loongson/llvm-project/_build_lldb/t' (loongarch64)
Process 2455626 stopped
* thread #1, name = 't', stop reason = breakpoint 1.1
    frame #0: 0x0000555555554714 t`foo at test.c:4:1
   1    #include <stdio.h>
   2
   3    void foo() {
-> 4    asm volatile ("movgr2fr.d $fs2, $ra":::"$fs2");
   5    }
   6    int main() {
   7    asm volatile ("movgr2fr.d $fs2, $sp":::"$fs2");
(lldb) si
Process 2455626 stopped
* thread #1, name = 't', stop reason = instruction step into
    frame #0: 0x0000555555554718 t`foo at test.c:4:1
   1    #include <stdio.h>
   2
   3    void foo() {
-> 4    asm volatile ("movgr2fr.d $fs2, $ra":::"$fs2");
   5    }
   6    int main() {
   7    asm volatile ("movgr2fr.d $fs2, $sp":::"$fs2");
(lldb) f 1
frame #1: 0x0000555555554768 t`main at test.c:8:1
   5    }
   6    int main() {
   7    asm volatile ("movgr2fr.d $fs2, $sp":::"$fs2");
-> 8    foo();
   9    return 0;
   10   }
(lldb) register read -a
General Purpose Registers:
        r1 = 0x0000555555554768  t`main + 40 at test.c:8:1
        r3 = 0x00007ffffffef780
       r22 = 0x00007ffffffef7b0
       r23 = 0x00007ffffffef918
       r24 = 0x0000000000000001
       r25 = 0x0000000000000000
       r26 = 0x000055555555be08  t`__do_global_dtors_aux_fini_array_entry
       r27 = 0x0000555555554740  t`main at test.c:6
       r28 = 0x00007ffffffef928
       r29 = 0x00007ffff7febc88  ld-linux-loongarch-lp64d.so.1`_rtld_global_ro
       r30 = 0x000055555555be08  t`__do_global_dtors_aux_fini_array_entry
        pc = 0x0000555555554768  t`main + 40 at test.c:8:1
33 registers were unavailable.

Floating Point Registers:
       f13 = 0x00007ffffffef780 !!!!! wrong register
       f24 = 0xffffffffffffffff
       f25 = 0xffffffffffffffff
       f26 = 0x0000555555554768  t`main + 40 at test.c:8:1
       f27 = 0xffffffffffffffff
       f28 = 0xffffffffffffffff
       f29 = 0xffffffffffffffff
       f30 = 0xffffffffffffffff
       f31 = 0xffffffffffffffff
32 registers were unavailable.
```
With this patch:
```
The previous operations are the same.
(lldb) register read -a
General Purpose Registers:
        r1 = 0x0000555555554768  t`main + 40 at test.c:8:1
        r3 = 0x00007ffffffef780
       r22 = 0x00007ffffffef7b0
       r23 = 0x00007ffffffef918
       r24 = 0x0000000000000001
       r25 = 0x0000000000000000
       r26 = 0x000055555555be08  t`__do_global_dtors_aux_fini_array_entry
       r27 = 0x0000555555554740  t`main at test.c:6
       r28 = 0x00007ffffffef928
       r29 = 0x00007ffff7febc88  ld-linux-loongarch-lp64d.so.1`_rtld_global_ro
       r30 = 0x000055555555be08  t`__do_global_dtors_aux_fini_array_entry
        pc = 0x0000555555554768  t`main + 40 at test.c:8:1
33 registers were unavailable.

Floating Point Registers:
       f24 = 0xffffffffffffffff
       f25 = 0xffffffffffffffff
       f26 = 0x00007ffffffef780
       f27 = 0xffffffffffffffff
       f28 = 0xffffffffffffffff
       f29 = 0xffffffffffffffff
       f30 = 0xffffffffffffffff
       f31 = 0xffffffffffffffff
33 registers were unavailable.
```

Reviewed By: SixWeining

Pull Request: llvm/llvm-project#120391
Naghasan pushed a commit that referenced this pull request Jun 5, 2025
Fixes #123300

What is seen 
```
clang-repl> int x = 42;
clang-repl> auto capture = [&]() { return x * 2; };
In file included from <<< inputs >>>:1:
input_line_4:1:17: error: non-local lambda expression cannot have a capture-default
    1 | auto capture = [&]() { return x * 2; };
      |                 ^
zsh: segmentation fault  clang-repl --Xcc="-v"

(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x8)
  * frame #0: 0x0000000107b4f8b8 libclang-cpp.19.1.dylib`clang::IncrementalParser::CleanUpPTU(clang::PartialTranslationUnit&) + 988
    frame #1: 0x0000000107b4f1b4 libclang-cpp.19.1.dylib`clang::IncrementalParser::ParseOrWrapTopLevelDecl() + 416
    frame intel#2: 0x0000000107b4fb94 libclang-cpp.19.1.dylib`clang::IncrementalParser::Parse(llvm::StringRef) + 612
    frame intel#3: 0x0000000107b52fec libclang-cpp.19.1.dylib`clang::Interpreter::ParseAndExecute(llvm::StringRef, clang::Value*) + 180
    frame intel#4: 0x0000000100003498 clang-repl`main + 3560
    frame intel#5: 0x000000018d39a0e0 dyld`start + 2360
```

Though the error is justified, we shouldn't be interested in exiting
through a segfault in such cases.

The issue is that empty named decls weren't being taken care of
resulting into this assert


https://github.com/llvm/llvm-project/blob/c1a229252617ed58f943bf3f4698bd8204ee0f04/clang/include/clang/AST/DeclarationName.h#L503

Can also be seen when the example is attempted through xeus-cpp-lite.


![image](https://github.com/user-attachments/assets/9b0e6ead-138e-4b06-9ad9-fcb9f8d5bf6e)
Naghasan pushed a commit that referenced this pull request Jun 5, 2025
# Symptom

We have seen SIGSEGV like this:
```
* thread #1, name = 'lldb-server', stop reason = SIGSEGV
    frame #0: 0x00007f39e529c993 libc.so.6`__pthread_kill_internal(signo=11, threadid=<unavailable>) at pthread_kill.c:46:37
    ...
  * frame intel#5: 0x000056027c94fe48 lldb-server`lldb_private::process_linux::GetPtraceScope() + 72
    frame intel#6: 0x000056027c92f94f lldb-server`lldb_private::process_linux::NativeProcessLinux::Attach(int) + 1087
    ...
```
See [full stack trace](https://pastebin.com/X0d6QhYj).

This happens on Linux where LLDB doesn't have access to
`/proc/sys/kernel/yama/ptrace_scope`.

A similar error (an unchecked `Error`) can be reproduced by running the
newly added unit test without the fix. See the "Test" section below.


# Root cause

`GetPtraceScope()`
([code](https://github.com/llvm/llvm-project/blob/328f40f408c218f25695ea42c844e43bef38660b/lldb/source/Plugins/Process/Linux/Procfs.cpp#L77))
has the following `if` statement:
```
llvm::Expected<int> lldb_private::process_linux::GetPtraceScope() {
  ErrorOr<std::unique_ptr<MemoryBuffer>> ptrace_scope_file =
      getProcFile("sys/kernel/yama/ptrace_scope");
  if (!*ptrace_scope_file)
    return errorCodeToError(ptrace_scope_file.getError());
  ...
}
```

The intention of the `if` statement is to check whether the
`ptrace_scope_file` is an `Error` or not, and return the error if it is.
However, the `operator*` of `ErrorOr` returns the value that is stored
(which is a `std::unique_ptr<MemoryBuffer>`), so what the `if` condition
actually do is to check if the unique pointer is non-null.

Note that the method `ErrorOr::getStorage()` ([called
by](https://github.com/llvm/llvm-project/blob/328f40f408c218f25695ea42c844e43bef38660b/llvm/include/llvm/Support/ErrorOr.h#L162-L164)
`ErrorOr::operator *`) **does** assert on whether or not `HasError` has
been set (see
[ErrorOr.h](https://github.com/llvm/llvm-project/blob/328f40f408c218f25695ea42c844e43bef38660b/llvm/include/llvm/Support/ErrorOr.h#L235-L243)).
However, it seems this wasn't executed, probably because the LLDB was a
release build.

# Fix

The fix is simply remove the `*` in the said `if` statement.
Naghasan pushed a commit that referenced this pull request Jun 27, 2025
With non -O0, the call stack is not preserved, like malloc_shared will
be inlined, the call stack would be like
```
 #0 in int* sycl::_V1::malloc_host<int>(unsigned long, sycl::_V1::context const&, sycl::_V1::property_list const&, sycl::_V1::detail::code_location const&) /tmp/syclws/include/sycl/usm.hpp:215:27
 #1 in ?? (/lib/x86_64-linux-gnu/libc.so.6+0x757867a2a1c9)
 intel#2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x757867a2a28a)
```
instead of
```
 #0 in int* sycl::_V1::malloc_host<int>(unsigned long, sycl::_V1::context const&, sycl::_V1::property_list const&, sycl::_V1::detail::code_location const&) /tmp/syclws/include/sycl/usm.hpp:215:27
 #1 in int* sycl::_V1::malloc_host<int>(unsigned long, sycl::_V1::queue const&, sycl::_V1::property_list const&, sycl::_V1::detail::code_location const&) /tmp/syclws/include/sycl/usm.hpp:223:10
 intel#2 in main /tmp/syclws/llvm/sycl/test-e2e/MemorySanitizer/track-origins/check_host_usm_initialized_on_host.cpp:15:17
 intel#3 in ?? (/lib/x86_64-linux-gnu/libc.so.6+0x7a67f842a1c9)
 intel#4 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x7a67f842a28a)
```

Also, add env to every %{run} directive to make sure they are not
affected by system env.
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