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@cjappl cjappl commented Sep 23, 2024

NOTE: This is a preview PR showing the most complex refactor of the deduplication work. I want to make sure this is generally OK with you and still fits with our vision of the architecture.

Why?

We now use the unwound stack for two operations.

  1. (not visible in this PR) We use the unwound stack to deduplicate on the entire stack
  2. We print the stack

Instead of unwinding twice, we need to be smart about where we calculate it.

What's going on here?

Removal of pc, bp, simplification of DiagnosticsInfo

Instead of keeping pc and bp with the DiagnosticsInfo, we pass it into ExpectNotRealtime. This means we can greatly simplify the DiagnosticsInfo class

Callback "OnErrorAction" now takes the stack directly

To ensure we re-use the same stack for deduplication and printing, we now pass it back to the "OnErrorAction" and it can decide what to do with it. In the DefaultErrorAction, we just print the stack, this leads to:

Deleting the PrintStackTrace function

If we already have an unwound stack, we have nothing to do in this function.


__sanitizer::BufferedStackTrace stack;
stack.Unwind(caller_pc, caller_bp, nullptr,
/*fast*/ true);
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Getting the stack here is essential for deduplication. See the next change in the series here:

https://github.com/cjappl/llvm-project/pull/9/files#diff-26b1e9b52cc6bd23ad235825b8438ded1867285654d29b60536c5e87876adb3cR39-R46

@cjappl cjappl force-pushed the refactor_stack_location branch from 8c41f5a to 2489c94 Compare September 24, 2024 16:02
@cjappl cjappl force-pushed the refactor_stack_location branch from 2489c94 to 87bc32b Compare September 24, 2024 16:20
@cjappl cjappl force-pushed the exit_statistics branch 2 times, most recently from 8fb6078 to 310bada Compare September 25, 2024 14:26
cjappl pushed a commit that referenced this pull request Sep 26, 2024
Random testing found that the Z3 wrapper does not support UnarySymExpr,
which was added recently and not included in the original Z3 wrapper.
For now, just avoid submitting expressions to Z3 to avoid compiler
crashes.

Some crash context ...

clang -cc1 -analyze -analyzer-checker=core z3-unarysymexpr.c
-analyzer-constraints=z3

Unsupported expression to reason about!
UNREACHABLE executed at
clang/include/clang/StaticAnalyzer/Core/PathSensitive/SMTConstraintManager.h:297!

Stack dump:
3. <root>/clang/test/Analysis/z3-unarysymexpr.c:13:7: Error evaluating
branch #0 <addr> llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) #1
<addr> llvm::sys::RunSignalHandlers() #8 <addr>
clang::ento::SimpleConstraintManager::assumeAux(
llvm::IntrusiveRefCntPtr<clang::ento::ProgramState const>,
clang::ento::NonLoc, bool) #9 <addr>
clang::ento::SimpleConstraintManager::assume(
llvm::IntrusiveRefCntPtr<clang::ento::ProgramState const>,
clang::ento::NonLoc, bool)

Co-authored-by: einvbri <[email protected]>
cjappl pushed a commit that referenced this pull request Oct 21, 2024
…en issue

Since llvm#109628 landed, this test
has been failing on 32-bit Arm.

This is due to a codegen problem (whether added or uncovered by the change,
not known) where the trap instruction is placed after the frame pointer
and link register are restored.

llvm#113154

So the code was:
```
std::__1::vector<int>::operator[](unsigned int):
  sub sp, sp, #8
  str r0, [sp, #4]
  str r1, [sp]
  add sp, sp, #8
  .inst 0xe7ffdefe
  bx lr
```
When lldb saw the trap, the PC was inside operator[] but the frame
information actually pointed to g.

This bug only happens for leaf functions so adding a return type
works around it:
```
std::__1::vector<int>::operator[](unsigned int):
  push {r11, lr}
  mov r11, sp
  sub sp, sp, #8
  str r0, [sp, #4]
  str r1, [sp]
  mov sp, r11
  pop {r11, lr}
  .inst 0xe7ffdefe
  bx lr
```
(and operator[] should return T& anyway)

Now the PC location and frame information should match and the
test passes.
cjappl pushed a commit that referenced this pull request Nov 19, 2024
… depobj construct (llvm#114221)

A codegen crash is occurring when a depend object was initialized with
omp_all_memory in the depobj directive.
llvm#114214
The root cause of issue looks to be the improper handling of the
dependency list when omp_all_memory was specified.

The change introduces the use of OMPTaskDataTy to manage dependencies.
The buildDependences function is called to construct the dependency
list, and the list is iterated over to emit and store the dependencies.

Reduced Test Case : 
```
#include <omp.h>

int main()

{ omp_depend_t obj; #pragma omp depobj(obj) depend(inout: omp_all_memory) }
```

```
 #1 0x0000000003de6623 SignalHandler(int) Signals.cpp:0:0
 #2 0x00007f8e4a6b990f (/lib64/libpthread.so.0+0x1690f)
 #3 0x00007f8e4a117d2a raise (/lib64/libc.so.6+0x4ad2a)
 #4 0x00007f8e4a1193e4 abort (/lib64/libc.so.6+0x4c3e4)
 #5 0x00007f8e4a10fc69 __assert_fail_base (/lib64/libc.so.6+0x42c69)
 #6 0x00007f8e4a10fcf1 __assert_fail (/lib64/libc.so.6+0x42cf1)
 #7 0x0000000004114367 clang::CodeGen::CodeGenFunction::EmitOMPDepobjDirective(clang::OMPDepobjDirective const&) (/opt/cray/pe/cce/18.0.1/cce-clang/x86_64/bin/clang-18+0x4114367)
 #8 0x00000000040f8fac clang::CodeGen::CodeGenFunction::EmitStmt(clang::Stmt const*, llvm::ArrayRef<clang::Attr const*>) (/opt/cray/pe/cce/18.0.1/cce-clang/x86_64/bin/clang-18+0x40f8fac)
 #9 0x00000000040ff4fb clang::CodeGen::CodeGenFunction::EmitCompoundStmtWithoutScope(clang::CompoundStmt const&, bool, clang::CodeGen::AggValueSlot) (/opt/cray/pe/cce/18.0.1/cce-clang/x86_64/bin/clang-18+0x40ff4fb)
#10 0x00000000041847b2 clang::CodeGen::CodeGenFunction::EmitFunctionBody(clang::Stmt const*) (/opt/cray/pe/cce/18.0.1/cce-clang/x86_64/bin/clang-18+0x41847b2)
#11 0x0000000004199e4a clang::CodeGen::CodeGenFunction::GenerateCode(clang::GlobalDecl, llvm::Function*, clang::CodeGen::CGFunctionInfo const&) (/opt/cray/pe/cce/18.0.1/cce-clang/x86_64/bin/clang-18+0x4199e4a)
#12 0x00000000041f7b9d clang::CodeGen::CodeGenModule::EmitGlobalFunctionDefinition(clang::GlobalDecl, llvm::GlobalValue*) (/opt/cray/pe/cce/18.0.1/cce-clang/x86_64/bin/clang-18+0x41f7b9d)
#13 0x00000000041f16a3 clang::CodeGen::CodeGenModule::EmitGlobalDefinition(clang::GlobalDecl, llvm::GlobalValue*) (/opt/cray/pe/cce/18.0.1/cce-clang/x86_64/bin/clang-18+0x41f16a3)
#14 0x00000000041fd954 clang::CodeGen::CodeGenModule::EmitDeferred() (/opt/cray/pe/cce/18.0.1/cce-clang/x86_64/bin/clang-18+0x41fd954)
realtime-sanitizer#15 0x0000000004200277 clang::CodeGen::CodeGenModule::Release() (/opt/cray/pe/cce/18.0.1/cce-clang/x86_64/bin/clang-18+0x4200277)
realtime-sanitizer#16 0x00000000046b6a49 (anonymous namespace)::CodeGeneratorImpl::HandleTranslationUnit(clang::ASTContext&) ModuleBuilder.cpp:0:0
realtime-sanitizer#17 0x00000000046b4cb6 clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) (/opt/cray/pe/cce/18.0.1/cce-clang/x86_64/bin/clang-18+0x46b4cb6)
realtime-sanitizer#18 0x0000000006204d5c clang::ParseAST(clang::Sema&, bool, bool) (/opt/cray/pe/cce/18.0.1/cce-clang/x86_64/bin/clang-18+0x6204d5c)
realtime-sanitizer#19 0x000000000496b278 clang::FrontendAction::Execute() (/opt/cray/pe/cce/18.0.1/cce-clang/x86_64/bin/clang-18+0x496b278)
realtime-sanitizer#20 0x00000000048dd074 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/cray/pe/cce/18.0.1/cce-clang/x86_64/bin/clang-18+0x48dd074)
realtime-sanitizer#21 0x0000000004a38092 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/cray/pe/cce/18.0.1/cce-clang/x86_64/bin/clang-18+0x4a38092)
realtime-sanitizer#22 0x0000000000fd4e9c cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/cray/pe/cce/18.0.1/cce-clang/x86_64/bin/clang-18+0xfd4e9c)
realtime-sanitizer#23 0x0000000000fcca73 ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
realtime-sanitizer#24 0x0000000000fd140c clang_main(int, char**, llvm::ToolContext const&) (/opt/cray/pe/cce/18.0.1/cce-clang/x86_64/bin/clang-18+0xfd140c)
realtime-sanitizer#25 0x0000000000ee2ef3 main (/opt/cray/pe/cce/18.0.1/cce-clang/x86_64/bin/clang-18+0xee2ef3)
realtime-sanitizer#26 0x00007f8e4a10224c __libc_start_main (/lib64/libc.so.6+0x3524c)
realtime-sanitizer#27 0x0000000000fcaae9 _start /home/abuild/rpmbuild/BUILD/glibc-2.31/csu/../sysdeps/x86_64/start.S:120:0
clang: error: unable to execute command: Aborted
```

---------

Co-authored-by: Chandra Ghale <[email protected]>
cjappl pushed a commit that referenced this pull request Nov 20, 2024
…onger cause a crash (llvm#116569)

This PR fixes a bug introduced by llvm#110199, which causes any half float
argument to crash the compiler on MIPS64.

Currently compiling this bit of code with `llc -mtriple=mips64`: 
```
define void @half_args(half %a) nounwind {
entry:
        ret void
}
```

Crashes with the following log:
```
LLVM ERROR: unable to allocate function argument #0
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.	Program arguments: llc -mtriple=mips64
1.	Running pass 'Function Pass Manager' on module '<stdin>'.
2.	Running pass 'MIPS DAG->DAG Pattern Instruction Selection' on function '@half_args'
 #0 0x000055a3a4013df8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/davide/Ps2/rps2-tools/prefix/bin/llc+0x32d0df8)
 #1 0x000055a3a401199e llvm::sys::RunSignalHandlers() (/home/davide/Ps2/rps2-tools/prefix/bin/llc+0x32ce99e)
 #2 0x000055a3a40144a8 SignalHandler(int) Signals.cpp:0:0
 #3 0x00007f00bde558c0 __restore_rt libc_sigaction.c:0:0
 #4 0x00007f00bdea462c __pthread_kill_implementation ./nptl/pthread_kill.c:44:76
 #5 0x00007f00bde55822 gsignal ./signal/../sysdeps/posix/raise.c:27:6
 #6 0x00007f00bde3e4af abort ./stdlib/abort.c:81:7
 #7 0x000055a3a3f80e3c llvm::report_fatal_error(llvm::Twine const&, bool) (/home/davide/Ps2/rps2-tools/prefix/bin/llc+0x323de3c)
 #8 0x000055a3a2e20dfa (/home/davide/Ps2/rps2-tools/prefix/bin/llc+0x20dddfa)
 #9 0x000055a3a2a34e20 llvm::MipsTargetLowering::LowerFormalArguments(llvm::SDValue, unsigned int, bool, llvm::SmallVectorImpl<llvm::ISD::InputArg> const&, llvm::SDLoc const&, llvm::SelectionDAG&, llvm::SmallVectorImpl<llvm::SDValue>&) const MipsISelLowering.cpp:0:0
#10 0x000055a3a3d896a9 llvm::SelectionDAGISel::LowerArguments(llvm::Function const&) (/home/davide/Ps2/rps2-tools/prefix/bin/llc+0x30466a9)
#11 0x000055a3a3e0b3ec llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function const&) (/home/davide/Ps2/rps2-tools/prefix/bin/llc+0x30c83ec)
#12 0x000055a3a3e09e21 llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&) (/home/davide/Ps2/rps2-tools/prefix/bin/llc+0x30c6e21)
#13 0x000055a3a2aae1ca llvm::MipsDAGToDAGISel::runOnMachineFunction(llvm::MachineFunction&) MipsISelDAGToDAG.cpp:0:0
#14 0x000055a3a3e07706 llvm::SelectionDAGISelLegacy::runOnMachineFunction(llvm::MachineFunction&) (/home/davide/Ps2/rps2-tools/prefix/bin/llc+0x30c4706)
realtime-sanitizer#15 0x000055a3a3051ed6 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (/home/davide/Ps2/rps2-tools/prefix/bin/llc+0x230eed6)
realtime-sanitizer#16 0x000055a3a35a3ec9 llvm::FPPassManager::runOnFunction(llvm::Function&) (/home/davide/Ps2/rps2-tools/prefix/bin/llc+0x2860ec9)
realtime-sanitizer#17 0x000055a3a35ac3b2 llvm::FPPassManager::runOnModule(llvm::Module&) (/home/davide/Ps2/rps2-tools/prefix/bin/llc+0x28693b2)
realtime-sanitizer#18 0x000055a3a35a499c llvm::legacy::PassManagerImpl::run(llvm::Module&) (/home/davide/Ps2/rps2-tools/prefix/bin/llc+0x286199c)
realtime-sanitizer#19 0x000055a3a262abbb main (/home/davide/Ps2/rps2-tools/prefix/bin/llc+0x18e7bbb)
realtime-sanitizer#20 0x00007f00bde3fc4c __libc_start_call_main ./csu/../sysdeps/nptl/libc_start_call_main.h:74:3
realtime-sanitizer#21 0x00007f00bde3fd05 call_init ./csu/../csu/libc-start.c:128:20
realtime-sanitizer#22 0x00007f00bde3fd05 __libc_start_main@GLIBC_2.2.5 ./csu/../csu/libc-start.c:347:5
realtime-sanitizer#23 0x000055a3a2624921 _start /builddir/glibc-2.39/csu/../sysdeps/x86_64/start.S:117:0
```

This is caused by the fact that after the change, `f16`s are no longer
lowered as `f32`s in calls.

Two possible fixes are available:
- Update calling conventions to properly support passing `f16` as
integers.
- Update `useFPRegsForHalfType()` to return `true` so that `f16` are
still kept in `f32` registers, as before llvm#110199.

This PR implements the first solution to not introduce any more ABI
changes as llvm#110199 already did.

As of what is the correct ABI for halfs, I don't think there is a
correct answer. GCC doesn't support halfs on MIPS, and I couldn't find
any information on old MIPS ABI manuals either.
@cjappl cjappl closed this Nov 20, 2024
cjappl pushed a commit that referenced this pull request Dec 6, 2024
## Description

This PR fixes a segmentation fault that occurs when passing options
requiring arguments via `-Xopenmp-target=<triple>`. The issue was that
the function `Driver::getOffloadArchs` did not properly parse the
extracted option, but instead assumed it was valid, leading to a crash
when incomplete arguments were provided.

## Backtrace

```sh
llvm-project/build/bin/clang++ main.cpp -fopenmp=libomp -fopenmp-targets=powerpc64le-ibm-linux-gnu -Xopenmp-target=powerpc64le-ibm-linux-gnu -o 
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script.
Stack dump:
0.      Program arguments: llvm-project/build/bin/clang++ main.cpp -fopenmp=libomp -fopenmp-targets=powerpc64le-ibm-linux-gnu -Xopenmp-target=powerpc64le-ibm-linux-gnu -o
1.      Compilation construction
2.      Building compilation actions
 #0 0x0000562fb21c363b llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (llvm-project/build/bin/clang+++0x392f63b)
 #1 0x0000562fb21c0e3c SignalHandler(int) Signals.cpp:0:0
 #2 0x00007fcbf6c81420 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x14420)
 #3 0x0000562fb1fa5d70 llvm::opt::Option::matches(llvm::opt::OptSpecifier) const (llvm-project/build/bin/clang+++0x3711d70)
 #4 0x0000562fb2a78e7d clang::driver::Driver::getOffloadArchs(clang::driver::Compilation&, llvm::opt::DerivedArgList const&, clang::driver::Action::OffloadKind, clang::driver::ToolChain const*, bool) const (llvm-project/build/bin/clang+++0x41e4e7d)
 #5 0x0000562fb2a7a9aa clang::driver::Driver::BuildOffloadingActions(clang::driver::Compilation&, llvm::opt::DerivedArgList&, std::pair<clang::driver::types::ID, llvm::opt::Arg const*> const&, clang::driver::Action*) const (.part.1164) Driver.cpp:0:0
 #6 0x0000562fb2a7c093 clang::driver::Driver::BuildActions(clang::driver::Compilation&, llvm::opt::DerivedArgList&, llvm::SmallVector<std::pair<clang::driver::types::ID, llvm::opt::Arg const*>, 16u> const&, llvm::SmallVector<clang::driver::Action*, 3u>&) const (llvm-project/build/bin/clang+++0x41e8093)
 #7 0x0000562fb2a8395d clang::driver::Driver::BuildCompilation(llvm::ArrayRef<char const*>) (llvm-project/build/bin/clang+++0x41ef95d)
 #8 0x0000562faf92684c clang_main(int, char**, llvm::ToolContext const&) (llvm-project/build/bin/clang+++0x109284c)
 #9 0x0000562faf826cc6 main (llvm-project/build/bin/clang+++0xf92cc6)
#10 0x00007fcbf6699083 __libc_start_main /build/glibc-LcI20x/glibc-2.31/csu/../csu/libc-start.c:342:3
#11 0x0000562faf923a5e _start (llvm-project/build/bin/clang+++0x108fa5e)
[1]    2628042 segmentation fault (core dumped)   main.cpp -fopenmp=libomp -fopenmp-targets=powerpc64le-ibm-linux-gnu  -o
```
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