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@kyulee-com kyulee-com closed this Sep 18, 2024
@kyulee-com kyulee-com deleted the thin5 branch September 18, 2024 12:48
@kyulee-com kyulee-com restored the thin5 branch September 18, 2024 12:49
kyulee-com pushed a commit that referenced this pull request Sep 21, 2024
When SPARC Asan testing is enabled by PR llvm#107405, many Linux/sparc64
tests just hang like
```
#0  0xf7ae8e90 in syscall () from /usr/lib32/libc.so.6
#1  0x701065e8 in __sanitizer::FutexWait(__sanitizer::atomic_uint32_t*, unsigned int) ()
    at compiler-rt/lib/sanitizer_common/sanitizer_linux.cpp:766
llvm#2  0x70107c90 in Wait ()
    at compiler-rt/lib/sanitizer_common/sanitizer_mutex.cpp:35
llvm#3  0x700f7cac in Lock ()
    at compiler-rt/lib/asan/../sanitizer_common/sanitizer_mutex.h:196
llvm#4  Lock ()
    at compiler-rt/lib/asan/../sanitizer_common/sanitizer_thread_registry.h:98
llvm#5  LockThreads ()
    at compiler-rt/lib/asan/asan_thread.cpp:489
llvm#6  0x700e9c8c in __asan::BeforeFork() ()
    at compiler-rt/lib/asan/asan_posix.cpp:157
llvm#7  0xf7ac83f4 in ?? () from /usr/lib32/libc.so.6
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
```
It turns out that this happens in tests using `internal_fork` (e.g.
invoking `llvm-symbolizer`): unlike most other Linux targets, which use
`clone`, Linux/sparc64 has to use `__fork` instead. While `clone`
doesn't trigger `pthread_atfork` handlers, `__fork` obviously does,
causing the hang.

To avoid this, this patch disables `InstallAtForkHandler` and lets the
ASan tests run to completion.

Tested on `sparc64-unknown-linux-gnu`.
kyulee-com pushed a commit that referenced this pull request Sep 21, 2024
…ap (llvm#108825)

This attempts to improve user-experience when LLDB stops on a
verbose_trap. Currently if a `__builtin_verbose_trap` triggers, we
display the first frame above the call to the verbose_trap. So in the
newly added test case, we would've previously stopped here:
```
(lldb) run
Process 28095 launched: '/Users/michaelbuch/a.out' (arm64)
Process 28095 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = Bounds error: out-of-bounds access
    frame #1: 0x0000000100003f5c a.out`std::__1::vector<int>::operator[](this=0x000000016fdfebef size=0, (null)=10) at verbose_trap.cpp:6:9
   3    template <typename T>
   4    struct vector {
   5        void operator[](unsigned) {
-> 6            __builtin_verbose_trap("Bounds error", "out-of-bounds access");
   7        }
   8    };
```

After this patch, we would stop in the first non-`std` frame:
```
(lldb) run
Process 27843 launched: '/Users/michaelbuch/a.out' (arm64)
Process 27843 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = Bounds error: out-of-bounds access
    frame llvm#2: 0x0000000100003f44 a.out`g() at verbose_trap.cpp:14:5
   11  
   12   void g() {
   13       std::vector<int> v;
-> 14       v[10];
   15   }
   16  
```

rdar://134490328
kyulee-com pushed a commit that referenced this pull request Sep 21, 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() llvm#8 <addr>
clang::ento::SimpleConstraintManager::assumeAux(
llvm::IntrusiveRefCntPtr<clang::ento::ProgramState const>,
clang::ento::NonLoc, bool) llvm#9 <addr>
clang::ento::SimpleConstraintManager::assume(
llvm::IntrusiveRefCntPtr<clang::ento::ProgramState const>,
clang::ento::NonLoc, bool)

Co-authored-by: einvbri <vince.a.bridgers@ericsson.com>
kyulee-com pushed a commit that referenced this pull request Oct 3, 2024
…ext is not fully initialized (llvm#110481)

As this comment around target initialization implies:
```
  // This can be NULL if we don't know anything about the architecture or if
  // the target for an architecture isn't enabled in the llvm/clang that we
  // built
```

There are cases where we might fail to call `InitBuiltinTypes` when
creating the backing `ASTContext` for a `TypeSystemClang`. If that
happens, the builtins `QualType`s, e.g., `VoidPtrTy`/`IntTy`/etc., are
not initialized and dereferencing them as we do in
`GetBuiltinTypeForEncodingAndBitSize` (and other places) will lead to
nullptr-dereferences. Example backtrace:
```
(lldb) run
Assertion failed: (!isNull() && "Cannot retrieve a NULL type pointer"), function getCommonPtr, file Type.h, line 958.
Process 2680 stopped
* thread llvm#15, name = '<lldb.process.internal-state(pid=2712)>', stop reason = hit program assert
    frame llvm#4: 0x000000010cdf3cdc liblldb.20.0.0git.dylib`DWARFASTParserClang::ExtractIntFromFormValue(lldb_private::CompilerType const&, lldb_private::plugin::dwarf::DWARFFormValue const&) const (.cold.1) + 
liblldb.20.0.0git.dylib`DWARFASTParserClang::ParseObjCMethod(lldb_private::ObjCLanguage::MethodName const&, lldb_private::plugin::dwarf::DWARFDIE const&, lldb_private::CompilerType, ParsedDWARFTypeAttributes
, bool) (.cold.1):
->  0x10cdf3cdc <+0>:  stp    x29, x30, [sp, #-0x10]!
    0x10cdf3ce0 <+4>:  mov    x29, sp
    0x10cdf3ce4 <+8>:  adrp   x0, 545
    0x10cdf3ce8 <+12>: add    x0, x0, #0xa25 ; "ParseObjCMethod"
Target 0: (lldb) stopped.
(lldb) bt
* thread llvm#15, name = '<lldb.process.internal-state(pid=2712)>', stop reason = hit program assert
    frame #0: 0x0000000180d08600 libsystem_kernel.dylib`__pthread_kill + 8
    frame #1: 0x0000000180d40f50 libsystem_pthread.dylib`pthread_kill + 288
    frame llvm#2: 0x0000000180c4d908 libsystem_c.dylib`abort + 128
    frame llvm#3: 0x0000000180c4cc1c libsystem_c.dylib`__assert_rtn + 284
  * frame llvm#4: 0x000000010cdf3cdc liblldb.20.0.0git.dylib`DWARFASTParserClang::ExtractIntFromFormValue(lldb_private::CompilerType const&, lldb_private::plugin::dwarf::DWARFFormValue const&) const (.cold.1) + 
    frame llvm#5: 0x0000000109d30acc liblldb.20.0.0git.dylib`lldb_private::TypeSystemClang::GetBuiltinTypeForEncodingAndBitSize(lldb::Encoding, unsigned long) + 1188
    frame llvm#6: 0x0000000109aaaed4 liblldb.20.0.0git.dylib`DynamicLoaderMacOS::NotifyBreakpointHit(void*, lldb_private::StoppointCallbackContext*, unsigned long long, unsigned long long) + 384
```

This patch adds a one-time user-visible warning for when we fail to
initialize the AST to indicate that initialization went wrong for the
given target. Additionally, we add checks for whether one of the
`ASTContext` `QualType`s is invalid before dereferencing any builtin
types.

The warning would look as follows:
```
(lldb) target create "a.out"
Current executable set to 'a.out' (arm64).
(lldb) b main
warning: Failed to initialize builtin ASTContext types for target 'some-unknown-triple'. Printing variables may behave unexpectedly.
Breakpoint 1: where = a.out`main + 8 at stepping.cpp:5:14, address = 0x0000000100003f90
```

rdar://134869779
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