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Add contracts representation and parsing. Much thanks to Peter for th…#3

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EricWF wants to merge 1802 commits intomainfrom
contracts
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Add contracts representation and parsing. Much thanks to Peter for th…#3
EricWF wants to merge 1802 commits intomainfrom
contracts

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@EricWF EricWF commented Jun 19, 2024

…e initial implementation

BitfieldSize(nullptr) {}
};

class ContractSpecifiers {
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TODO: Remove this, I actually haven't used it yet.

Though I haven't fixed the parsing yet.

case Builtin::BI__builtin_operator_delete:
return HandleOperatorDeleteCall(Info, E);

case Builtin::BI__builtin_contract_assert: {
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FIXME: This also is unused and needs to be removed.

ContractStmts need to be handled differently.

Builder.CreateCall(FnAssume, ArgValue);
return RValue::get(nullptr);
}
case Builtin::BI__builtin_contract_assert: {
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Remove this as well.

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I think the next step would be to merge the 2 vectors of ContractStmts everywhere, it's really not ergonomic and one ought to be enough (it's should be easy to either sort it , or filter it)

]

_allStandards = ["c++03", "c++11", "c++14", "c++17", "c++20", "c++23", "c++26"]
_allStandards = ["c++03", "c++11", "c++14", "c++17", "c++20", "c++23", "c++26", "c++2c"]

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What's the difference between 2c and 26?

enum { ResultNameDeclOffset = 0, ConditionOffset = 1, Count = 2 };

public:
// These types correspond to the three C++ 'await_suspend' return variants

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haha :)

if (Tok.is(tok::identifier) && NextToken().is(tok::colon)) {
if (CK != ContractKind::Post) {
// Only post contracts can have a result name
Diag(Tok.getLocation(), diag::err_expected) << tok::identifier;

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That diag looks weird

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Yeah, it's wrong.

Actions.getASTContext().BoolTy);
}

T.consumeClose();

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you want to keep that so that you know where the contract ends

Comment on lines 4389 to 4460
void Parser::ParsePostContract(Declarator &DeclaratorInfo) {
ConsumeToken();

ParseScope ParamScope(this, Scope::DeclScope |
Scope::FunctionDeclarationScope |
Scope::FunctionPrototypeScope);

DeclaratorChunk::FunctionTypeInfo FTI = DeclaratorInfo.getFunctionTypeInfo();
for (unsigned i = 0; i != FTI.NumParams; ++i) {
ParmVarDecl *Param = cast<ParmVarDecl>(FTI.Params[i].Param);
Actions.ActOnReenterCXXMethodParameter(getCurScope(), Param);
}

if (Tok.isNot(tok::l_paren)) {
Diag(Tok.getLocation(), diag::err_expected) << tok::l_paren;
return;
}
ConsumeParen();

// Post contracts start with <identifier> colon <expression>
// As we have to support the "auto f() post (r : r > 42) {...}" case, we cannot parse here
// the return type is not guaranteed to be known until after the function body parses

/*
if (Tok.isNot(tok::identifier)) {
Diag(Tok.getLocation(), diag::err_expected) << tok::identifier;
return;
}

ParsingDeclSpec DS(*this);

ParsedTemplateInfo TemplateInfo;
DeclSpecContext DSContext = getDeclSpecContextFromDeclaratorContext(DeclaratorContext::Block);
ParseDeclarationSpecifiers(DS, TemplateInfo, AS_none, DSContext);

ParsedAttributes LocalAttrs(AttrFactory);
ParsingDeclarator D(*this, DS, LocalAttrs, DeclaratorContext::Block);

D.setObjectType(getAsFunction().getReturnType());
IdentifierInfo *Id = Tok.getIdentifierInfo();
SourceLocation IdLoc = ConsumeToken();
D.setIdentifier(Id, IdLoc);

Decl* ThisDecl = Actions.ActOnDeclarator(getCurScope(), D);
Actions.ActOnUninitializedDecl(ThisDecl);
Actions.FinalizeDeclaration(ThisDecl);
D.complete(ThisDecl);
if (Tok.isNot(tok::colon)) {
Diag(Tok.getLocation(), diag::err_expected) << tok::colon;
return;
}

ExprResult Expr = ParseExpression();
if (Expr.isInvalid()) {
Diag(Tok.getLocation(), diag::err_invalid_pcs);
return;
}
DeclaratorInfo.addPostContract(Expr.get());
*/
ExprResult Expr = ParseExpression();
if (Expr.isInvalid()) {
Diag(Tok.getLocation(), diag::err_invalid_pcs);
return;
}
// DeclaratorInfo.addPostContract(Expr.get());

if (Tok.isNot(tok::r_paren)) {
Diag(Tok.getLocation(), diag::err_expected) << tok::r_paren;
return;
}
ConsumeParen();
}

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Is that dead code?

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Yeah, but I still might want to reference it while building the result name introducer decl later.

Comment on lines 2440 to 2442
// FIXME(EricWF): This seems really worg.
ParsedAttributes attrs(AttrFactory);
MaybeParseCXX11Attributes(attrs);

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looks fine to me? (except we never do anything with these attributes)
We might want to make ContractStmt an AttributedStmt

Comment on lines 2585 to 2590
def ContractAssert : Builtin {
let Spellings = ["__builtin_contract_assert"];
let Attributes = [NoThrow, Constexpr];

let Prototype = "void(bool)";
}

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dead code?

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Yep.

Comment on lines 1678 to 1686

def fcontracts_impl_strategy : Joined<["-"], "fcontracts_strategy=">,
HelpText<"Specify contract implementation strategy. The default value is 'callee'.">,
Values<"0,1,2">,
Visibility<[ClangOption, CC1Option]>,
NormalizedValuesScope<"LangOptions::ContractImplStrategy">,
NormalizedValues<["Callee", "Both", "Split"]>,
MarshallingInfoEnum<LangOpts<"ContractStrategy">, "Callee">;

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I like the ambition!

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That's all peter :-) I'm going to only emit callee side.

Comment on lines +2110 to +2118
//===--------------------------------------------------------------------===//
// C++ Contracts
/*
ExceptionSpecificationType Parser::tryParseExceptionSpecification(
bool Delayed, SourceRange &SpecificationRange,
SmallVectorImpl<ParsedType> &DynamicExceptions,
SmallVectorImpl<SourceRange> &DynamicExceptionRanges,
ExprResult &NoexceptExpr, CachedTokens *&) {
*/

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Weird comment

]

_allStandards = ["c++03", "c++11", "c++14", "c++17", "c++20", "c++23", "c++26"]
_allStandards = ["c++03", "c++11", "c++14", "c++17", "c++20", "c++23", "c++26", "c++2c"]

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What is the difference between 26 and 2c?

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Nothing, I thought I needed it, but I don't.

@EricWF
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EricWF commented Jun 21, 2024

I think the next step would be to merge the 2 vectors of ContractStmts everywhere, it's really not ergonomic and one ought to be enough (it's should be easy to either sort it , or filter it)

I think it's also needed to check that two declarations have equivalent contract specifications, since using two vectors removes the ordering of pre/post.

SourceLocation IdLoc = ConsumeToken();
(void)Id;
(void)IdLoc;
// FIXME(ericwf): Actually build the result name introducer
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@cor3ntin I'm struggling to get the return type out of the parser here. Thoughts?

vporpo and others added 24 commits July 3, 2024 12:04
…on, OpaqueInst (llvm#97343)

A very basic implementation of sandboxir::
`Fuction`
`Argument`
`Constant`
`Instruction`
`OpaqueInst`
If the instruction is marked for deletion, better to drop all its
operands and mark them for deletion too (if allowed). It allows to have
more vectorizable patterns and generate less useless extractelement
instructions.

Reviewers: RKSimon

Reviewed By: RKSimon

Pull Request: llvm#97409
The new round-robin algorithm overrides the hash-based distribution of
functions to modules. It achieves a more even number of functions per
module when the number of functions is close to the number of requested
modules. It's not in use by default and is available under a new flag.
zext does not allow converting vector shadow to scalar, so we must
manually convert it prior to calling zext in materializeOneCheck, for
which the 'ConvertedShadow' parameter isn't actually guaranteed to be
scalar (1). Note that it is safe/no-op to call convertShadowToScalar on
a shadow that is already scalar.

In contrast, the storeOrigin function already converts the (potentially
vector) shadow to scalar; we add a comment to note why it is load
bearing.

(1) In materializeInstructionChecks():
"// Disable combining in some cases. TrackOrigins checks each shadow to
pick
 // correct origin.
 bool Combine = !MS.TrackOrigins;
 ...
       if (!Combine) {
        materializeOneCheck(IRB, ConvertedShadow, ShadowData.Origin);
        continue;
      }"
…s space when generating intrinsics (llvm#96836)

This PR aims to factor in the allocation address space provided by an
architectures data layout when generating the intrinsic instructions,
this allows them to be lowered later with the address spaces in tow.
This aligns the intrinsic creation with the LLVM IRBuilder's
https://github.com/llvm/llvm-project/blob/main/llvm/include/llvm/IR/IRBuilder.h#L1053

This is also necessary for the below example to compile for OpenMP AMD
GPU and not ICE the compiler in ISEL as AMD's stackrestore and stacksave
are expected to have the appropriate allocation address space for AMD
GPU.

program main
    integer(4), allocatable :: test
    allocate(test)

!$omp target map(tofrom:test)
    do i = 1, 10
      test = test + 50
    end do
!$omp end target

  deallocate(test)
end program

The PR also fixes the issue I opened a while ago which hits the same
error when compiling for AMDGPU:
llvm#82368

Although, you have to have the appropriate GPU LIBC and Fortran offload
runtime (both compiled for AMDGPU) added to the linker for the command
or it will reach another ISEL error and ICE weirdly. But with the
pre-requisites it works fine with this PR.
Added Demangle to Profile link components to fix shared build.
…lvm#97360)

llvm#95482 is a reland of
llvm#88024.
llvm#95482 keeps indexing memory
usage reasonable by using unordered_map and doesn't make other changes
to originally reviewed code.

While discussing possible ways to minimize indexing memory usage, Teresa
asked whether I need `ExportSetTy` as a map or a set is sufficient. This
PR implements the idea. It uses a set rather than a map to track exposed
ValueInfos.

Currently, `ExportLists` has two use cases, and neither needs to track a
ValueInfo's import/export status. So using a set is sufficient and
correct.
1) In both in-process and distributed ThinLTO, it's used to decide if a
function or global variable is visible [1] from another module after importing
creates additional cross-module references.
     * If a cross-module call edge is seen today, the callee must be visible
       to another module without keeping track of its export status already.
       For instance, this [2] is how callees of direct calls get exported.
2) For in-process ThinLTO [3], it's used to compute lto cache key.
     * The cache key computation already hashes [4] 'ImportList' , and 'ExportList' is
        determined by 'ImportList'. So it's fine to not track 'import type' for export list.

[1] https://github.com/llvm/llvm-project/blob/66cd8ec4c08252ebc73c82e4883a8da247ed146b/llvm/lib/LTO/LTO.cpp#L1815-L1819
[2] https://github.com/llvm/llvm-project/blob/66cd8ec4c08252ebc73c82e4883a8da247ed146b/llvm/lib/LTO/LTO.cpp#L1783-L1794
[3] https://github.com/llvm/llvm-project/blob/66cd8ec4c08252ebc73c82e4883a8da247ed146b/llvm/lib/LTO/LTO.cpp#L1494-L1496
[4] https://github.com/llvm/llvm-project/blob/b76100e220591fab2bf0a4917b216439f7aa4b09/llvm/lib/LTO/LTO.cpp#L194-L222
…U. NFC

We have an existing VT variable that should match N0.getValueType.
Add requires line to not test when the target architecture isn't
supported.

Technically we could make it a bit less restrictive, but want green
builds.
The two options are discussed in a few comments around
llvm#91280 (comment)

* -Wa,--crel: error "-Wa,--allow-experimental-crel must be specified to use -Wa,--crel..."
* -Wa,--allow-experimental-crel: no-op
* -Wa,--crel,--allow-experimental-crel: enable CREL in the integrated assembler (llvm#91280)

MIPS's little-endian n64 ABI messed up the `r_info` field in
relocations. While this could be fixed with CREL, my intention is to
avoid complication in assembler/linker. The implementation simply
doesn't allow CREL for MIPS.

Link: https://discourse.llvm.org/t/rfc-crel-a-compact-relocation-format-for-elf/77600

Pull Request: llvm#97378
- created integration tests for libc hdrgen 
- implemented sorting function names in yaml files through script
We only handled the easy LDS case before. Handle the other address
spaces
with the more complicated legality logic.
…#97329)

Reordered Function class parameter "standards" to make more logical
sense and to match the ordering in the add_function function.
Deleted the yaml_combined folder and moved contained files to the yaml
folder.
Updated math.yaml file with the recently added math functions in spec.td
Refactors legacy ranges writers to create a writer for each instance of
a DWO file.

We now write out everything into .debug_ranges after the all the DWO
files are processed. This also changes the order that ranges is written
out in, as before we wrote out while in the main CU processing loop and
we now iterate through the CU buckets created by partitionCUs, after the
main processing loop.
…7489)

Using the same range reduction as `sin`, `cos`, and `sincos`:
1) Reducing `x = k*pi/128 + u`, with `|u| <= pi/256`, and `u` is in
double-double.
2) Approximate `tan(u)` using degree-9 Taylor polynomial.
3) Compute
```
   tan(x) ~ (sin(k*pi/128) + tan(u) * cos(k*pi/128)) / (cos(k*pi/128) - tan(u) * sin(k*pi/128))
```
using the fast double-double division algorithm in [the CORE-MATH
project](https://gitlab.inria.fr/core-math/core-math/-/blob/master/src/binary64/tan/tan.c#L1855).
4) Perform relative-error Ziv's accuracy test
5) If the accuracy tests failed, we redo the computations using 128-bit
precision `DyadicFloat`.

Fixes llvm#96930
…nary operator& (llvm#97596)

Currently, `TreeTransform::TransformCXXOperatorCallExpr` calls
`TreeTransform::TransformAddressOfOperand` to transform the first
operand of a `CXXOperatorCallExpr` when its `OverloadOperatorKind` is
`OO_Amp` -- regardless of arity. This results in the first operand of
binary `operator&` being incorrectly transformed as if it was the
operand of the address of operator in cases such as the following:
```
struct A {
  int x;
};

void operator&(A, A);

template<typename T>
struct B {
  int f() {
    return T::x & 1; // invalid reference to 'A::x' is not diagnosed because 'T::x' is incorrectly transformed as if it was the operand of unary operator&
  }
};

template struct B<A>;
```
Prior to llvm#92318 we would build a `CXXDependentScopeMemberExpr` for
`T::x` (as with most dependent qualified names that were not member
qualified names). Since `TreeTransform::TransformAddressOfOperand` only
differs from `TransformExpr` for `DependentScopeDeclRefExpr` and
`UnresolvedLookupExpr` operands, `T::x` was transformed "correctly". Now
that we build a `DependentScopeDeclRefExpr` for `T::x`, it is
incorrectly transformed as if it was the operand of the address of
operator and we fail to diagnose the invalid reference to a non-static
data member. This patch fixes the issue by only calling
`TreeTransform::TransformAddressOfOperand` for `CXXOperatorCallExpr`s
with a single operand. This fixes llvm#97483.
The key was being dropped for external resources because they aren't
present in the dialect resource name mapper.
…n leading / trailing dimensions." (llvm#97652)

Reverts llvm#92934 because it breaks some lowering. To
repro: `mlir-opt -test-vector-transfer-flatten-patterns ~/repro.mlir`

```mlir
func.func @unit_dim_folding(%arg0: vector<1x1xf32>) -> vector<1x1xf32> {
  %cst = arith.constant dense<0.000000e+00> : vector<1x1xf32>
  %0 = arith.mulf %arg0, %cst : vector<1x1xf32>
  return %0 : vector<1x1xf32>
}
```
ldionne and others added 2 commits July 6, 2024 13:52
This makes the test suite forward-compatible with future versions of macOS.
Previously, the Lit features were built in a way that they would assume
that any newer macOS version doesn't contain any version of LLVM, which
doesn't make sense.
EricWF pushed a commit that referenced this pull request Jul 6, 2024
#3) (llvm#93315)

The ThreadLocalCache implementation is used by the MLIRContext (among
other things) to try to manage thread contention in the StorageUniquers.
There is a bunch of fancy shared pointer/weak pointer setups that
basically keeps everything alive across threads at the right time, but a
huge bottleneck is the `weak_ptr::lock` call inside the `::get` method.

This is because the `lock` method has to hit the atomic refcount several
times, and this is bottlenecking performance across many threads.
However, all this is doing is checking whether the storage is
initialized. Importantly, when the `PerThreadInstance` goes out of
scope, it does not remove all of its associated entries from the
thread-local hash map (it contains dangling `PerThreadInstance *` keys).
The `weak_ptr` also allows the thread local cache to synchronize with
the `PerThreadInstance`'s destruction:

1. if `ThreadLocalCache` destructs, the `weak_ptr`s that reference its
contained values are immediately invalidated
2. if `CacheType` destructs within a thread, any entries still live are
removed from the owning `PerThreadInstance`, and it locks the `weak_ptr`
first to ensure it's kept alive long enough for the removal.

This PR changes the TLC entries to contain a `shared_ptr<ValueT*>` and a
`weak_ptr<PerInstanceState>`. It gives the `PerInstanceState` entries a
`weak_ptr<ValueT*>` on top of the `unique_ptr<ValueT>`. This enables
`ThreadLocalCache::get` to check if the value is initialized by
dereferencing the `shared_ptr<ValueT*>` and check if the contained
pointer is null. When `PerInstanceState` destructs, the values inside
the TLC are written to nullptr. The TLC uses the
`weak_ptr<PerInstanceState>` to satisfy (2).

(1) is no longer the case. When `ThreadLocalCache` begins destruction,
the `weak_ptr<PerInstanceState>` are invalidated, but not the
`shared_ptr<ValueT*>`. This is OK: because the overall object is being
destroyed, `::get` cannot get called and because the
`shared_ptr<PerInstanceState>` finishes destruction before freeing the
pointer, it cannot get reallocated to another `ThreadLocalCache` during
destruction. I.e. the values inside the TLC associated with a
`PerInstanceState` cannot be read during destruction. The most important
thing is to make sure destruction of the TLC doesn't race with the
destructor of `PerInstanceState`. Because `PerInstanceState` carries
`weak_ptr` references into the TLC, we guarantee to not have any
use-after-frees.
EricWF added 10 commits July 6, 2024 13:55
The template stuff is a bit of a hack. I'm considering simply inserting
the statements into the function body and letting the existing code
handle the rest.

Also add some cheaky diagnostics, fix a few name lookup bugs, and
delete some old code.
There are also various experiements that need cleaning up,
specifically around builtins and source location.
Some work on constification, but a bunch of experiment that still needs
to be undone.

The addition of -fclang-contract-groups=foo=<semantic>, which still
needs better integrating with -fcontract-evaluation-semantic=.

The [[clang::contract_group("foo.bar")]] stuff works really well.
I'll be happy to try it in libc++.

What still needs to be done includes:
  * Coming up with a proper descriptor/format for the compiler-stl
    interface. It seems to me we'll want the ABI to be able to evolve
over time, and so we should pass a pointer to data + data descriptor of
some kind so that the STL can parse version of the header from different
compilers & versions.

  * Everything to do with parsing pre/post in inline member functions.
  * Contract redeclaration checking.
  * Constifying implicit this.
  * Code gen & constant evaluation for result names (and representation
    too).
  * Cleanup around experiments for source location & constification.
EricWF pushed a commit that referenced this pull request Jul 9, 2024
This test is currently flaky on a local Windows amd64 build. The reason
is that it relies on the order of `process.threads` but this order is
nondeterministic:

If we print lldb's inputs and outputs while running, we can see that the
breakpoints are always being set correctly, and always being hit:

```sh
runCmd: breakpoint set -f "main.c" -l 2
output: Breakpoint 1: where = a.out`func_inner + 1 at main.c:2:9, address = 0x0000000140001001

runCmd: breakpoint set -f "main.c" -l 7
output: Breakpoint 2: where = a.out`main + 17 at main.c:7:5, address = 0x0000000140001021

runCmd: run
output: Process 52328 launched: 'C:\workspace\llvm-project\llvm\build\lldb-test-build.noindex\functionalities\unwind\zeroth_frame\TestZerothFrame.test_dwarf\a.out' (x86_64)
Process 52328 stopped
* thread #1, stop reason = breakpoint 1.1
    frame #0: 0x00007ff68f6b1001 a.out`func_inner at main.c:2:9
   1    void func_inner() {
-> 2        int a = 1;  // Set breakpoint 1 here
                ^
   3    }
   4
   5    int main() {
   6        func_inner();
   7        return 0; // Set breakpoint 2 here
```

However, sometimes the backtrace printed in this test shows that the
process is stopped inside NtWaitForWorkViaWorkerFactory from
`ntdll.dll`:

```sh
Backtrace at the first breakpoint:
frame #0: 0x00007ffecc7b3bf4 ntdll.dll`NtWaitForWorkViaWorkerFactory + 20
frame #1: 0x00007ffecc74585e ntdll.dll`RtlClearThreadWorkOnBehalfTicket + 862
frame #2: 0x00007ffecc3e257d kernel32.dll`BaseThreadInitThunk + 29
frame #3: 0x00007ffecc76af28 ntdll.dll`RtlUserThreadStart + 40
```

When this happens, the test fails with an assertion error that the
stopped thread's zeroth frame's current line number does not match the
expected line number. This is because the test is looking at the wrong
thread: `process.threads[0]`.

If we print the list of threads each time the test is run, we notice
that threads are sometimes in a different order, within
`process.threads`:

```sh
Thread 0: thread #4: tid = 0x9c38, 0x00007ffecc7b3bf4 ntdll.dll`NtWaitForWorkViaWorkerFactory + 20
Thread 1: thread #2: tid = 0xa950, 0x00007ffecc7b3bf4 ntdll.dll`NtWaitForWorkViaWorkerFactory + 20
Thread 2: thread #1: tid = 0xab18, 0x00007ff64bc81001 a.out`func_inner at main.c:2:9, stop reason = breakpoint 1.1
Thread 3: thread #3: tid = 0xc514, 0x00007ffecc7b3bf4 ntdll.dll`NtWaitForWorkViaWorkerFactory + 20

Thread 0: thread #3: tid = 0x018c, 0x00007ffecc7b3bf4 ntdll.dll`NtWaitForWorkViaWorkerFactory + 20
Thread 1: thread #1: tid = 0x85c8, 0x00007ff7130c1001 a.out`func_inner at main.c:2:9, stop reason = breakpoint 1.1
Thread 2: thread #2: tid = 0xf344, 0x00007ffecc7b3bf4 ntdll.dll`NtWaitForWorkViaWorkerFactory + 20
Thread 3: thread #4: tid = 0x6a50, 0x00007ffecc7b3bf4 ntdll.dll`NtWaitForWorkViaWorkerFactory + 20
```

Use `self.thread()` to consistently select the correct thread, instead.

Co-authored-by: kendal <kendal@thebrowser.company>
EricWF pushed a commit that referenced this pull request Jul 9, 2024
…izations of function templates to USRGenerator (llvm#98027)

Given the following:
```
template<typename T>
struct A
{
    void f(int); // #1
    
    template<typename U>
    void f(U); // #2
    
    template<>
    void f<int>(int); // #3
};
```
Clang will generate the same USR for `#1` and `#2`. This patch fixes the
issue by including the template arguments of dependent class scope
explicit specializations in their USRs.
EricWF pushed a commit that referenced this pull request Jul 16, 2024
This patch adds a frame recognizer for Clang's
`__builtin_verbose_trap`, which behaves like a
`__builtin_trap`, but emits a failure-reason string into debug-info in
order for debuggers to display
it to a user.

The frame recognizer triggers when we encounter
a frame with a function name that begins with
`__clang_trap_msg`, which is the magic prefix
Clang emits into debug-info for verbose traps.
Once such frame is encountered we display the
frame function name as the `Stop Reason` and display that frame to the
user.

Example output:
```
(lldb) run
warning: a.out was compiled with optimization - stepping may behave oddly; variables may not be available.
Process 35942 launched: 'a.out' (arm64)
Process 35942 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = Misc.: Function is not implemented
    frame #1: 0x0000000100003fa4 a.out`main [inlined] Dummy::func(this=<unavailable>) at verbose_trap.cpp:3:5 [opt]
   1    struct Dummy {
   2      void func() {
-> 3        __builtin_verbose_trap("Misc.", "Function is not implemented");
   4      }
   5    };
   6
   7    int main() {
(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = Misc.: Function is not implemented
    frame #0: 0x0000000100003fa4 a.out`main [inlined] __clang_trap_msg$Misc.$Function is not implemented$ at verbose_trap.cpp:0 [opt]
  * frame #1: 0x0000000100003fa4 a.out`main [inlined] Dummy::func(this=<unavailable>) at verbose_trap.cpp:3:5 [opt]
    frame #2: 0x0000000100003fa4 a.out`main at verbose_trap.cpp:8:13 [opt]
    frame #3: 0x0000000189d518b4 dyld`start + 1988
```
EricWF pushed a commit that referenced this pull request Jul 26, 2024
…linux (llvm#99613)

Examples of the output:

ARM:
```
# ./a.out 
AddressSanitizer:DEADLYSIGNAL
=================================================================
==122==ERROR: AddressSanitizer: SEGV on unknown address 0x0000007a (pc 0x76e13ac0 bp 0x7eb7fd00 sp 0x7eb7fcc8 T0)
==122==The signal is caused by a READ memory access.
==122==Hint: address points to the zero page.
    #0 0x76e13ac0  (/lib/libc.so.6+0x7cac0)
    #1 0x76dce680 in gsignal (/lib/libc.so.6+0x37680)
    #2 0x005c2250  (/root/a.out+0x145250)
    #3 0x76db982c  (/lib/libc.so.6+0x2282c)
    #4 0x76db9918 in __libc_start_main (/lib/libc.so.6+0x22918)

==122==Register values:
 r0 = 0x00000000   r1 = 0x0000007a   r2 = 0x0000000b   r3 = 0x76d95020  
 r4 = 0x0000007a   r5 = 0x00000001   r6 = 0x005dcc5c   r7 = 0x0000010c  
 r8 = 0x0000000b   r9 = 0x76f9ece0  r10 = 0x00000000  r11 = 0x7eb7fd00  
r12 = 0x76dce670   sp = 0x7eb7fcc8   lr = 0x76e13ab4   pc = 0x76e13ac0  
AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV (/lib/libc.so.6+0x7cac0) 
==122==ABORTING
```

AArch64:
```
# ./a.out 
UndefinedBehaviorSanitizer:DEADLYSIGNAL
==99==ERROR: UndefinedBehaviorSanitizer: SEGV on unknown address 0x000000000063 (pc 0x007fbbbc5860 bp 0x007fcfdcb700 sp 0x007fcfdcb700 T99)
==99==The signal is caused by a UNKNOWN memory access.
==99==Hint: address points to the zero page.
    #0 0x007fbbbc5860  (/lib64/libc.so.6+0x82860)
    #1 0x007fbbb81578  (/lib64/libc.so.6+0x3e578)
    #2 0x00556051152c  (/root/a.out+0x3152c)
    #3 0x007fbbb6e268  (/lib64/libc.so.6+0x2b268)
    #4 0x007fbbb6e344  (/lib64/libc.so.6+0x2b344)
    #5 0x0055604e45ec  (/root/a.out+0x45ec)

==99==Register values:
 x0 = 0x0000000000000000   x1 = 0x0000000000000063   x2 = 0x000000000000000b   x3 = 0x0000007fbbb41440  
 x4 = 0x0000007fbbb41580   x5 = 0x3669288942d44cce   x6 = 0x0000000000000000   x7 = 0x00000055605110b0  
 x8 = 0x0000000000000083   x9 = 0x0000000000000000  x10 = 0x0000000000000000  x11 = 0x0000000000000000  
x12 = 0x0000007fbbdb3360  x13 = 0x0000000000010000  x14 = 0x0000000000000039  x15 = 0x00000000004113a0  
x16 = 0x0000007fbbb81560  x17 = 0x0000005560540138  x18 = 0x000000006474e552  x19 = 0x0000000000000063  
x20 = 0x0000000000000001  x21 = 0x000000000000000b  x22 = 0x0000005560511510  x23 = 0x0000007fcfdcb918  
x24 = 0x0000007fbbdb1b50  x25 = 0x0000000000000000  x26 = 0x0000007fbbdb2000  x27 = 0x000000556053f858  
x28 = 0x0000000000000000   fp = 0x0000007fcfdcb700   lr = 0x0000007fbbbc584c   sp = 0x0000007fcfdcb700  
UndefinedBehaviorSanitizer can not provide additional info.
SUMMARY: UndefinedBehaviorSanitizer: SEGV (/lib64/libc.so.6+0x82860) 
==99==ABORTING
```
EricWF pushed a commit that referenced this pull request Aug 7, 2024
…llvm#96782)

First commit's PR is llvm#96780

Combines the following instructions:
`ushll r0, r0, #0`
`shl r0, r0, #3`

Into:
`ushll r0, r0, #3`
EricWF pushed a commit that referenced this pull request Aug 24, 2024
…104523)

Compilers and language runtimes often use helper functions that are
fundamentally uninteresting when debugging anything but the
compiler/runtime itself. This patch introduces a user-extensible
mechanism that allows for these frames to be hidden from backtraces and
automatically skipped over when navigating the stack with `up` and
`down`.

This does not affect the numbering of frames, so `f <N>` will still
provide access to the hidden frames. The `bt` output will also print a
hint that frames have been hidden.

My primary motivation for this feature is to hide thunks in the Swift
programming language, but I'm including an example recognizer for
`std::function::operator()` that I wished for myself many times while
debugging LLDB.

rdar://126629381


Example output. (Yes, my proof-of-concept recognizer could hide even
more frames if we had a method that returned the function name without
the return type or I used something that isn't based off regex, but it's
really only meant as an example).

before:
```
(lldb) thread backtrace --filtered=false
* thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
  * frame #0: 0x0000000100001f04 a.out`foo(x=1, y=1) at main.cpp:4:10
    frame #1: 0x0000000100003a00 a.out`decltype(std::declval<int (*&)(int, int)>()(std::declval<int>(), std::declval<int>())) std::__1::__invoke[abi:se200000]<int (*&)(int, int), int, int>(__f=0x000000016fdff280, __args=0x000000016fdff224, __args=0x000000016fdff220) at invoke.h:149:25
    frame #2: 0x000000010000399c a.out`int std::__1::__invoke_void_return_wrapper<int, false>::__call[abi:se200000]<int (*&)(int, int), int, int>(__args=0x000000016fdff280, __args=0x000000016fdff224, __args=0x000000016fdff220) at invoke.h:216:12
    frame #3: 0x0000000100003968 a.out`std::__1::__function::__alloc_func<int (*)(int, int), std::__1::allocator<int (*)(int, int)>, int (int, int)>::operator()[abi:se200000](this=0x000000016fdff280, __arg=0x000000016fdff224, __arg=0x000000016fdff220) at function.h:171:12
    frame #4: 0x00000001000026bc a.out`std::__1::__function::__func<int (*)(int, int), std::__1::allocator<int (*)(int, int)>, int (int, int)>::operator()(this=0x000000016fdff278, __arg=0x000000016fdff224, __arg=0x000000016fdff220) at function.h:313:10
    frame #5: 0x0000000100003c38 a.out`std::__1::__function::__value_func<int (int, int)>::operator()[abi:se200000](this=0x000000016fdff278, __args=0x000000016fdff224, __args=0x000000016fdff220) const at function.h:430:12
    frame #6: 0x0000000100002038 a.out`std::__1::function<int (int, int)>::operator()(this= Function = foo(int, int) , __arg=1, __arg=1) const at function.h:989:10
    frame #7: 0x0000000100001f64 a.out`main(argc=1, argv=0x000000016fdff4f8) at main.cpp:9:10
    frame #8: 0x0000000183cdf154 dyld`start + 2476
(lldb) 
```

after

```
(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
  * frame #0: 0x0000000100001f04 a.out`foo(x=1, y=1) at main.cpp:4:10
    frame #1: 0x0000000100003a00 a.out`decltype(std::declval<int (*&)(int, int)>()(std::declval<int>(), std::declval<int>())) std::__1::__invoke[abi:se200000]<int (*&)(int, int), int, int>(__f=0x000000016fdff280, __args=0x000000016fdff224, __args=0x000000016fdff220) at invoke.h:149:25
    frame #2: 0x000000010000399c a.out`int std::__1::__invoke_void_return_wrapper<int, false>::__call[abi:se200000]<int (*&)(int, int), int, int>(__args=0x000000016fdff280, __args=0x000000016fdff224, __args=0x000000016fdff220) at invoke.h:216:12
    frame #6: 0x0000000100002038 a.out`std::__1::function<int (int, int)>::operator()(this= Function = foo(int, int) , __arg=1, __arg=1) const at function.h:989:10
    frame #7: 0x0000000100001f64 a.out`main(argc=1, argv=0x000000016fdff4f8) at main.cpp:9:10
    frame #8: 0x0000000183cdf154 dyld`start + 2476
Note: Some frames were hidden by frame recognizers
```
EricWF pushed a commit that referenced this pull request Oct 2, 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 #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 #2: 0x0000000180c4d908 libsystem_c.dylib`abort + 128
    frame #3: 0x0000000180c4cc1c libsystem_c.dylib`__assert_rtn + 284
  * frame #4: 0x000000010cdf3cdc liblldb.20.0.0git.dylib`DWARFASTParserClang::ExtractIntFromFormValue(lldb_private::CompilerType const&, lldb_private::plugin::dwarf::DWARFFormValue const&) const (.cold.1) + 
    frame #5: 0x0000000109d30acc liblldb.20.0.0git.dylib`lldb_private::TypeSystemClang::GetBuiltinTypeForEncodingAndBitSize(lldb::Encoding, unsigned long) + 1188
    frame #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
EricWF pushed a commit that referenced this pull request Oct 31, 2024
…ates explicitly specialized for an implicitly instantiated class template specialization (llvm#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; // #2
  };
};

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

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

static_assert(A<long>::B<int>::y == 2); // uses #3
static_assert(A<long>::B<int*>::y == 2); // uses #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 llvm#51051.
EricWF pushed a commit that referenced this pull request Jun 27, 2025
The function already exposes a work list to avoid deep recursion, this
commit starts utilizing it in a helper that could also lead to a deep
recursion.

We have observed this crash on `clang/test/C/C99/n590.c` with our
internal builds that enable aggressive optimizations and hit the limit
earlier than default release builds of Clang.

See the added test for an example with a deeper recursion that used to
crash in upstream Clang before this change with the following stack
trace:

```
  #0 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) /usr/local/google/home/ibiryukov/code/llvm-project/llvm/lib/Support/Unix/Signals.inc:804:13
  #1 llvm::sys::RunSignalHandlers() /usr/local/google/home/ibiryukov/code/llvm-project/llvm/lib/Support/Signals.cpp:106:18
  #2 SignalHandler(int, siginfo_t*, void*) /usr/local/google/home/ibiryukov/code/llvm-project/llvm/lib/Support/Unix/Signals.inc:0:3
  #3 (/lib/x86_64-linux-gnu/libc.so.6+0x3fdf0)
  #4 AnalyzeImplicitConversions(clang::Sema&, clang::Expr*, clang::SourceLocation, bool) /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:12772:0
  #5 CheckCommaOperand /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:0:3
  #6 AnalyzeImplicitConversions /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:12644:7
  #7 AnalyzeImplicitConversions(clang::Sema&, clang::Expr*, clang::SourceLocation, bool) /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:12776:5
  #8 CheckCommaOperand /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:0:3
  #9 AnalyzeImplicitConversions /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:12644:7
 #10 AnalyzeImplicitConversions(clang::Sema&, clang::Expr*, clang::SourceLocation, bool) /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:12776:5
 #11 CheckCommaOperand /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:0:3
 llvm#12 AnalyzeImplicitConversions /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:12644:7
 llvm#13 AnalyzeImplicitConversions(clang::Sema&, clang::Expr*, clang::SourceLocation, bool) /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:12776:5
 llvm#14 CheckCommaOperand /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:0:3
 llvm#15 AnalyzeImplicitConversions /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:12644:7
 llvm#16 AnalyzeImplicitConversions(clang::Sema&, clang::Expr*, clang::SourceLocation, bool) /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:12776:5
 llvm#17 CheckCommaOperand /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:0:3
 llvm#18 AnalyzeImplicitConversions /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:12644:7
 llvm#19 AnalyzeImplicitConversions(clang::Sema&, clang::Expr*, clang::SourceLocation, bool) /usr/local/google/home/ibiryukov/code/llvm-project/clang/lib/Sema/SemaChecking.cpp:12776:5
... 700+ more stack frames.
```
EricWF pushed a commit that referenced this pull request Jul 22, 2025
Fix unnecessary conversion of C-String to StringRef in the `Cmp` lambda
inside `lookupLLVMIntrinsicByName`. This both fixes an ASAN error in the
code that happens when the `Name` StringRef passed in is not a Null
terminated StringRef, and additionally can potentially speed up the code
as well by eliminating the unnecessary computation of string length
every time a C String is converted to StringRef in this code (It seems
practically this computation is eliminated in optimized builds, but this
will avoid it in O0 builds as well).

Added a unit test that demonstrates this issue by building LLVM with
these options:

```
CMAKE_BUILD_TYPE=Debug
LLVM_USE_SANITIZER=Address
LLVM_OPTIMIZE_SANITIZED_BUILDS=OFF
```

The error reported is as follows:

```
==462665==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x5030000391a2 at pc 0x56525cc30bbf bp 0x7fff9e4ccc60 sp 0x7fff9e4cc428
READ of size 19 at 0x5030000391a2 thread T0
    #0 0x56525cc30bbe in strlen (upstream-llvm-second/llvm-project/build/unittests/IR/IRTests+0x713bbe) (BuildId: 0651acf1e582a4d2)
    #1 0x7f8ff22ad334 in std::char_traits<char>::length(char const*) /usr/bin/../lib/gcc/x86_64-linux-gnu/13/../../../../include/c++/13/bits/char_traits.h:399:9
    #2 0x7f8ff22a34a0 in llvm::StringRef::StringRef(char const*) /home/rjoshi/upstream-llvm-second/llvm-project/llvm/include/llvm/ADT/StringRef.h:96:33
    #3 0x7f8ff28ca184 in _ZZL25lookupLLVMIntrinsicByNameN4llvm8ArrayRefIjEENS_9StringRefES2_ENK3$_0clIjPKcEEDaT_T0_ upstream-llvm-second/llvm-project/llvm/lib/IR/Intrinsics.cpp:673:18
```
EricWF pushed a commit that referenced this pull request Aug 7, 2025
…erver (llvm#148774)

Summary:
There was a deadlock was introduced by [PR
llvm#146441](llvm#146441) which changed
`CurrentThreadIsPrivateStateThread()` to
`CurrentThreadPosesAsPrivateStateThread()`. This change caused the
execution path in
[`ExecutionContextRef::SetTargetPtr()`](https://github.com/llvm/llvm-project/blob/10b5558b61baab59c7d3dff37ffdf0861c0cc67a/lldb/source/Target/ExecutionContext.cpp#L513)
to now enter a code block that was previously skipped, triggering
[`GetSelectedFrame()`](https://github.com/llvm/llvm-project/blob/10b5558b61baab59c7d3dff37ffdf0861c0cc67a/lldb/source/Target/ExecutionContext.cpp#L522)
which leads to a deadlock.

Thread 1 gets m_modules_mutex in
[`ModuleList::AppendImpl`](https://github.com/llvm/llvm-project/blob/96148f92146e5211685246722664e51ec730e7ba/lldb/source/Core/ModuleList.cpp#L218),
Thread 3 gets m_language_runtimes_mutex in
[`GetLanguageRuntime`](https://github.com/llvm/llvm-project/blob/96148f92146e5211685246722664e51ec730e7ba/lldb/source/Target/Process.cpp#L1501),
but then Thread 1 waits for m_language_runtimes_mutex in
[`GetLanguageRuntime`](https://github.com/llvm/llvm-project/blob/96148f92146e5211685246722664e51ec730e7ba/lldb/source/Target/Process.cpp#L1501)
while Thread 3 waits for m_modules_mutex in
[`ScanForGNUstepObjCLibraryCandidate`](https://github.com/llvm/llvm-project/blob/96148f92146e5211685246722664e51ec730e7ba/lldb/source/Plugins/LanguageRuntime/ObjC/GNUstepObjCRuntime/GNUstepObjCRuntime.cpp#L57).

This fixes the deadlock by adding a scoped block around the mutex lock
before the call to the notifier, and moved the notifier call outside of
the mutex-guarded section. The notifier call
[`NotifyModuleAdded`](https://github.com/llvm/llvm-project/blob/96148f92146e5211685246722664e51ec730e7ba/lldb/source/Target/Target.cpp#L1810)
should be thread-safe, since the module should be added to the
`ModuleList` before the mutex is released, and the notifier doesn't
modify the module list further, and the call is operates on local state
and the `Target` instance.

### Deadlocked Thread backtraces:
```
* thread #3, name = 'dbg.evt-handler', stop reason = signal SIGSTOP
  * frame #0: 0x00007f2f1e2973dc libc.so.6`futex_wait(private=0, expected=2, futex_word=0x0000563786bd5f40) at    futex-internal.h:146:13
   /*... a bunch of mutex related bt ... */    
   liblldb.so.21.0git`std::lock_guard<std::recursive_mutex>::lock_guard(this=0x00007f2f0f1927b0, __m=0x0000563786bd5f40) at std_mutex.h:229:19
    frame #8: 0x00007f2f27946eb7 liblldb.so.21.0git`ScanForGNUstepObjCLibraryCandidate(modules=0x0000563786bd5f28, TT=0x0000563786bd5eb8) at GNUstepObjCRuntime.cpp:60:41
    frame #9: 0x00007f2f27946c80 liblldb.so.21.0git`lldb_private::GNUstepObjCRuntime::CreateInstance(process=0x0000563785e1d360, language=eLanguageTypeObjC) at GNUstepObjCRuntime.cpp:87:8
    frame #10: 0x00007f2f2746fca5 liblldb.so.21.0git`lldb_private::LanguageRuntime::FindPlugin(process=0x0000563785e1d360, language=eLanguageTypeObjC) at LanguageRuntime.cpp:210:36
    frame #11: 0x00007f2f2742c9e3 liblldb.so.21.0git`lldb_private::Process::GetLanguageRuntime(this=0x0000563785e1d360, language=eLanguageTypeObjC) at Process.cpp:1516:9
    ...
    frame llvm#21: 0x00007f2f2750b5cc liblldb.so.21.0git`lldb_private::Thread::GetSelectedFrame(this=0x0000563785e064d0, select_most_relevant=DoNoSelectMostRelevantFrame) at Thread.cpp:274:48
    frame llvm#22: 0x00007f2f273f9957 liblldb.so.21.0git`lldb_private::ExecutionContextRef::SetTargetPtr(this=0x00007f2f0f193778, target=0x0000563786bd5be0, adopt_selected=true) at ExecutionContext.cpp:525:32
    frame llvm#23: 0x00007f2f273f9714 liblldb.so.21.0git`lldb_private::ExecutionContextRef::ExecutionContextRef(this=0x00007f2f0f193778, target=0x0000563786bd5be0, adopt_selected=true) at ExecutionContext.cpp:413:3
    frame llvm#24: 0x00007f2f270e80af liblldb.so.21.0git`lldb_private::Debugger::GetSelectedExecutionContext(this=0x0000563785d83bc0) at Debugger.cpp:1225:23
    frame llvm#25: 0x00007f2f271bb7fd liblldb.so.21.0git`lldb_private::Statusline::Redraw(this=0x0000563785d83f30, update=true) at Statusline.cpp:136:41
    ...
* thread #1, name = 'lldb', stop reason = signal SIGSTOP
  * frame #0: 0x00007f2f1e2973dc libc.so.6`futex_wait(private=0, expected=2, futex_word=0x0000563785e1dd98) at futex-internal.h:146:13
   /*... a bunch of mutex related bt ... */    
   liblldb.so.21.0git`std::lock_guard<std::recursive_mutex>::lock_guard(this=0x00007ffe62be0488, __m=0x0000563785e1dd98) at std_mutex.h:229:19
    frame #8: 0x00007f2f2742c8d1 liblldb.so.21.0git`lldb_private::Process::GetLanguageRuntime(this=0x0000563785e1d360, language=eLanguageTypeC_plus_plus) at Process.cpp:1510:41
    frame #9: 0x00007f2f2743c46f liblldb.so.21.0git`lldb_private::Process::ModulesDidLoad(this=0x0000563785e1d360, module_list=0x00007ffe62be06a0) at Process.cpp:6082:36
    ...
    frame llvm#13: 0x00007f2f2715cf03 liblldb.so.21.0git`lldb_private::ModuleList::AppendImpl(this=0x0000563786bd5f28, module_sp=ptr = 0x563785cec560, use_notifier=true) at ModuleList.cpp:246:19
    frame llvm#14: 0x00007f2f2715cf4c liblldb.so.21.0git`lldb_private::ModuleList::Append(this=0x0000563786bd5f28, module_sp=ptr = 0x563785cec560, notify=true) at ModuleList.cpp:251:3
    ...
    frame llvm#19: 0x00007f2f274349b3 liblldb.so.21.0git`lldb_private::Process::ConnectRemote(this=0x0000563785e1d360, remote_url=(Data = "connect://localhost:1234", Length = 24)) at Process.cpp:3250:9
    frame llvm#20: 0x00007f2f27411e0e liblldb.so.21.0git`lldb_private::Platform::DoConnectProcess(this=0x0000563785c59990, connect_url=(Data = "connect://localhost:1234", Length = 24), plugin_name=(Data = "gdb-remote", Length = 10), debugger=0x0000563785d83bc0, stream=0x00007ffe62be3128, target=0x0000563786bd5be0, error=0x00007ffe62be1ca0) at Platform.cpp:1926:23
```

## Test Plan:
Built a hello world a.out
Run server in one terminal:
```
~/llvm/build/Debug/bin/lldb-server g :1234 a.out
```
Run client in another terminal
```
~/llvm/build/Debug/bin/lldb -o "gdb-remote 1234" -o "b hello.cc:3"
```

Before:
Client hangs indefinitely
```
~/llvm/build/Debug/bin/lldb -o "gdb-remote 1234" -o "b main"
(lldb) gdb-remote 1234

^C^C
```

After:
```
~/llvm/build/Debug/bin/lldb -o "gdb-remote 1234" -o "b hello.cc:3"
(lldb) gdb-remote 1234
Process 837068 stopped
* thread #1, name = 'a.out', stop reason = signal SIGSTOP
    frame #0: 0x00007ffff7fe4a60
ld-linux-x86-64.so.2`_start:
->  0x7ffff7fe4a60 <+0>: movq   %rsp, %rdi
    0x7ffff7fe4a63 <+3>: callq  0x7ffff7fe5780 ; _dl_start at rtld.c:522:1

ld-linux-x86-64.so.2`_dl_start_user:
    0x7ffff7fe4a68 <+0>: movq   %rax, %r12
    0x7ffff7fe4a6b <+3>: movl   0x18067(%rip), %eax ; _dl_skip_args
(lldb) b hello.cc:3
Breakpoint 1: where = a.out`main + 15 at hello.cc:4:13, address = 0x00005555555551bf
(lldb) c
Process 837068 resuming
Process 837068 stopped
* thread #1, name = 'a.out', stop reason = breakpoint 1.1
    frame #0: 0x00005555555551bf a.out`main at hello.cc:4:13
   1   	#include <iostream>
   2
   3   	int main() {
-> 4   	  std::cout << "Hello World" << std::endl;
   5   	  return 0;
   6   	}
```
EricWF pushed a commit that referenced this pull request Sep 26, 2025
A few improvements to logging when lldb-dap is started in **Server
Mode** AND when the **`lldb-dap.logFolder`** setting is used (not
`lldb-dap.log-path`).

### Improvement #1
**Avoid the prompt of restarting the server when starting each debug
session.**

That prompt is caused by the combination of the following facts:
1. The log filename changes every time a new debug session is starting
(see
[here](https://github.com/llvm/llvm-project/blob/9d6062c490548a5e6fea103e010ab3c9bc73a86d/lldb/tools/lldb-dap/src-ts/logging.ts#L47))
2. The log filename is passed to the server via an environment variable
called "LLDBDAP_LOG" (see
[here](https://github.com/llvm/llvm-project/blob/9d6062c490548a5e6fea103e010ab3c9bc73a86d/lldb/tools/lldb-dap/src-ts/debug-adapter-factory.ts#L263-L269))
3. All environment variables are put into the "spawn info" variable (see
[here](https://github.com/llvm/llvm-project/blob/9d6062c490548a5e6fea103e010ab3c9bc73a86d/lldb/tools/lldb-dap/src-ts/lldb-dap-server.ts#L170-L172)).
4. The old and new "spawn info" are compared to decide if a prompt
should show (see
[here](https://github.com/llvm/llvm-project/blob/9d6062c490548a5e6fea103e010ab3c9bc73a86d/lldb/tools/lldb-dap/src-ts/lldb-dap-server.ts#L107-L110)).

The fix is to remove the "LLDBDAP_LOG" from the "spawn info" variable,
so that the same server can be reused if the log path is the only thing
that has changed.

### Improvement #2
**Avoid log file conflict when multiple users share a machine and start
server in the same second.**

The problem: If two users start lldb-dap server in the same second, they
will share the same log path. The first user will create the log file.
The second user will find that they cannot access the same file, so
their server will fail to start.

The fix is to add a part of the VS Code session ID to the log filename.

### Improvement #3
**Avoid restarting the server when the order of environment variables
changed.**

This is done by sorting the environment variables before putting them
into the "spawn info".
EricWF pushed a commit that referenced this pull request Oct 23, 2025
**Mitigation for:** google/sanitizers#749

**Disclosure:** I'm not an ASan compiler expert yet (I'm trying to
learn!), I primarily work in the runtime. Some of this PR was developed
with the help of AI tools (primarily as a "fuzzy `grep` engine"), but
I've manually refined and tested the output, and can speak for every
line. In general, I used it only to orient myself and for
"rubberducking".

**Context:**

The msvc ASan team (👋 ) has received an internal request to improve
clang's exception handling under ASan for Windows. Namely, we're
interested in **mitigating** this bug:
google/sanitizers#749

To summarize, today, clang + ASan produces a false-positive error for
this program:

```C++
#include <cstdio>
#include <exception>
int main()
{
	try	{
		throw std::exception("test");
	}catch (const std::exception& ex){
		puts(ex.what());
	}
	return 0;
}
```

The error reads as such:


```
C:\Users\dajusto\source\repros\upstream>type main.cpp
#include <cstdio>
#include <exception>
int main()
{
        try     {
                throw std::exception("test");
        }catch (const std::exception& ex){
                puts(ex.what());
        }
        return 0;
}
C:\Users\dajusto\source\repros\upstream>"C:\Users\dajusto\source\repos\llvm-project\build.runtimes\bin\clang.exe" -fsanitize=address -g -O0 main.cpp

C:\Users\dajusto\source\repros\upstream>a.exe
=================================================================
==19112==ERROR: AddressSanitizer: access-violation on unknown address 0x000000000000 (pc 0x7ff72c7c11d9 bp 0x0080000ff960 sp 0x0080000fcf50 T0)
==19112==The signal is caused by a READ memory access.
==19112==Hint: address points to the zero page.
    #0 0x7ff72c7c11d8 in main C:\Users\dajusto\source\repros\upstream\main.cpp:8
    #1 0x7ff72c7d479f in _CallSettingFrame C:\repos\msvc\src\vctools\crt\vcruntime\src\eh\amd64\handlers.asm:49
    #2 0x7ff72c7c8944 in __FrameHandler3::CxxCallCatchBlock(struct _EXCEPTION_RECORD *) C:\repos\msvc\src\vctools\crt\vcruntime\src\eh\frame.cpp:1567
    #3 0x7ffb4a90e3e5  (C:\WINDOWS\SYSTEM32\ntdll.dll+0x18012e3e5)
    #4 0x7ff72c7c1128 in main C:\Users\dajusto\source\repros\upstream\main.cpp:6
    #5 0x7ff72c7c33db in invoke_main C:\repos\msvc\src\vctools\crt\vcstartup\src\startup\exe_common.inl:78
    #6 0x7ff72c7c33db in __scrt_common_main_seh C:\repos\msvc\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288
    #7 0x7ffb49b05c06  (C:\WINDOWS\System32\KERNEL32.DLL+0x180035c06)
    #8 0x7ffb4a8455ef  (C:\WINDOWS\SYSTEM32\ntdll.dll+0x1800655ef)

==19112==Register values:
rax = 0  rbx = 80000ff8e0  rcx = 27d76d00000  rdx = 80000ff8e0
rdi = 80000fdd50  rsi = 80000ff6a0  rbp = 80000ff960  rsp = 80000fcf50
r8  = 100  r9  = 19930520  r10 = 8000503a90  r11 = 80000fd540
r12 = 80000fd020  r13 = 0  r14 = 80000fdeb8  r15 = 0
AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: access-violation C:\Users\dajusto\source\repros\upstream\main.cpp:8 in main
==19112==ABORTING
```

The root of the issue _appears to be_ that ASan's instrumentation is
incompatible with Window's assumptions for instantiating `catch`-block's
parameters (`ex` in the snippet above).

The nitty gritty details are lost on me, but I understand that to make
this work without loss of ASan coverage, a "serious" refactoring is
needed. In the meantime, users risk false positive errors when pairing
ASan + catch-block parameters on Windows.

**To mitigate this** I think we should avoid instrumenting catch-block
parameters on Windows. It appears to me this is as "simple" as marking
catch block parameters as "uninteresting" in
`AddressSanitizer::isInterestingAlloca`. My manual tests seem to confirm
this.

I believe this is strictly better than today's status quo, where the
runtime generates false positives. Although we're now explicitly
choosing to instrument less, the benefit is that now more programs can
run with ASan without _funky_ macros that disable ASan on exception
blocks.

**This PR:** implements the mitigation above, and creates a simple new
test for it.

_Thanks!_

---------

Co-authored-by: Antonio Frighetto <me@antoniofrighetto.com>
EricWF pushed a commit that referenced this pull request Nov 18, 2025
…am (llvm#167724)

This got exposed by `09262656f32ab3f2e1d82e5342ba37eecac52522`.

The underlying stream of `m_os` is referenced by the `TextDiagnostic`
member of `TextDiagnosticPrinter`. It got turned into a
`llvm::formatted_raw_ostream` in the commit above. When
`~TextDiagnosticPrinter` (and thus `~TextDiagnostic`) is invoked, we now
call `~formatted_raw_ostream`, which tries to access the underlying
stream. But `m_os` was already deleted because it is earlier in the
order of destruction in `TextDiagnosticPrinter`. Move the `m_os` member
before the `TextDiagnosticPrinter` to avoid a use-after-free.

Drive-by:
* Also move the `m_output` member which the `m_os` holds a reference to.
The fact it's a reference indicates the expectation is most likely that
the string outlives the stream.

The ASAN macOS bot is currently failing with this:
```
08:15:39  =================================================================
08:15:39  ==61103==ERROR: AddressSanitizer: heap-use-after-free on address 0x60600012cf40 at pc 0x00012140d304 bp 0x00016eecc850 sp 0x00016eecc848
08:15:39  READ of size 8 at 0x60600012cf40 thread T0
08:15:39      #0 0x00012140d300 in llvm::formatted_raw_ostream::releaseStream() FormattedStream.h:205
08:15:39      #1 0x00012140d3a4 in llvm::formatted_raw_ostream::~formatted_raw_ostream() FormattedStream.h:145
08:15:39      #2 0x00012604abf8 in clang::TextDiagnostic::~TextDiagnostic() TextDiagnostic.cpp:721
08:15:39      #3 0x00012605dc80 in clang::TextDiagnosticPrinter::~TextDiagnosticPrinter() TextDiagnosticPrinter.cpp:30
08:15:39      #4 0x00012605dd5c in clang::TextDiagnosticPrinter::~TextDiagnosticPrinter() TextDiagnosticPrinter.cpp:27
08:15:39      #5 0x0001231fb210 in (anonymous namespace)::StoringDiagnosticConsumer::~StoringDiagnosticConsumer() ClangModulesDeclVendor.cpp:47
08:15:39      #6 0x0001231fb3bc in (anonymous namespace)::StoringDiagnosticConsumer::~StoringDiagnosticConsumer() ClangModulesDeclVendor.cpp:47
08:15:39      #7 0x000129aa9d70 in clang::DiagnosticsEngine::~DiagnosticsEngine() Diagnostic.cpp:91
08:15:39      #8 0x0001230436b8 in llvm::RefCountedBase<clang::DiagnosticsEngine>::Release() const IntrusiveRefCntPtr.h:103
08:15:39      #9 0x0001231fe6c8 in (anonymous namespace)::ClangModulesDeclVendorImpl::~ClangModulesDeclVendorImpl() ClangModulesDeclVendor.cpp:93
08:15:39      #10 0x0001231fe858 in (anonymous namespace)::ClangModulesDeclVendorImpl::~ClangModulesDeclVendorImpl() ClangModulesDeclVendor.cpp:93
...
08:15:39
08:15:39  0x60600012cf40 is located 32 bytes inside of 56-byte region [0x60600012cf20,0x60600012cf58)
08:15:39  freed by thread T0 here:
08:15:39      #0 0x0001018abb88 in _ZdlPv+0x74 (libclang_rt.asan_osx_dynamic.dylib:arm64e+0x4bb88)
08:15:39      #1 0x0001231fb1c0 in (anonymous namespace)::StoringDiagnosticConsumer::~StoringDiagnosticConsumer() ClangModulesDeclVendor.cpp:47
08:15:39      #2 0x0001231fb3bc in (anonymous namespace)::StoringDiagnosticConsumer::~StoringDiagnosticConsumer() ClangModulesDeclVendor.cpp:47
08:15:39      #3 0x000129aa9d70 in clang::DiagnosticsEngine::~DiagnosticsEngine() Diagnostic.cpp:91
08:15:39      #4 0x0001230436b8 in llvm::RefCountedBase<clang::DiagnosticsEngine>::Release() const IntrusiveRefCntPtr.h:103
08:15:39      #5 0x0001231fe6c8 in (anonymous namespace)::ClangModulesDeclVendorImpl::~ClangModulesDeclVendorImpl() ClangModulesDeclVendor.cpp:93
08:15:39      #6 0x0001231fe858 in (anonymous namespace)::ClangModulesDeclVendorImpl::~ClangModulesDeclVendorImpl() ClangModulesDeclVendor.cpp:93
...
08:15:39
08:15:39  previously allocated by thread T0 here:
08:15:39      #0 0x0001018ab760 in _Znwm+0x74 (libclang_rt.asan_osx_dynamic.dylib:arm64e+0x4b760)
08:15:39      #1 0x0001231f8dec in lldb_private::ClangModulesDeclVendor::Create(lldb_private::Target&) ClangModulesDeclVendor.cpp:732
08:15:39      #2 0x00012320af58 in lldb_private::ClangPersistentVariables::GetClangModulesDeclVendor() ClangPersistentVariables.cpp:124
08:15:39      #3 0x0001232111f0 in lldb_private::ClangUserExpression::PrepareForParsing(lldb_private::DiagnosticManager&, lldb_private::ExecutionContext&, bool) ClangUserExpression.cpp:536
08:15:39      #4 0x000123213790 in lldb_private::ClangUserExpression::Parse(lldb_private::DiagnosticManager&, lldb_private::ExecutionContext&, lldb_private::ExecutionPolicy, bool, bool) ClangUserExpression.cpp:647
08:15:39      #5 0x00012032b258 in lldb_private::UserExpression::Evaluate(lldb_private::ExecutionContext&, lldb_private::EvaluateExpressionOptions const&, llvm::StringRef, llvm::StringRef, std::__1::shared_ptr<lldb_private::ValueObject>&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>*, lldb_private::ValueObject*) UserExpression.cpp:280
08:15:39      #6 0x000120724010 in lldb_private::Target::EvaluateExpression(llvm::StringRef, lldb_private::ExecutionContextScope*, std::__1::shared_ptr<lldb_private::ValueObject>&, lldb_private::EvaluateExpressionOptions const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>*, lldb_private::ValueObject*) Target.cpp:2905
08:15:39      #7 0x00011fc7bde0 in lldb::SBTarget::EvaluateExpression(char const*, lldb::SBExpressionOptions const&) SBTarget.cpp:2305
08:15:39  ==61103==ABORTING
...
```
EricWF pushed a commit that referenced this pull request Dec 29, 2025
…lvm#159480)

When building rustc std for arm64e, core fails to compile successfully
with the error:
```
Constant ValueID not recognized.
UNREACHABLE executed at rust/src/llvm-project/llvm/lib/Transforms/Utils/FunctionComparator.cpp:523!
```

This is a result of function merging so I modified
FunctionComparator.cpp as the ConstantPtrAuth value would go unchecked
in the switch statement.

The test case is a reduction from the failure in core and fails on main
with:
```
********************
FAIL: LLVM :: Transforms/MergeFunc/ptrauth-const-compare.ll (59809 of 59995)
******************** TEST 'LLVM :: Transforms/MergeFunc/ptrauth-const-compare.ll' FAILED ********************
Exit Code: 2

Command Output (stdout):
--
# RUN: at line 3
/Users/oskarwirga/llvm-project/build/bin/opt -S -passes=mergefunc < /Users/oskarwirga/llvm-project/llvm/test/Transforms/MergeFunc/ptrauth-const-compare.ll | /Users/oskarwirga/llvm-project/build/bin/FileCheck /Users/oskarwirga/llvm-project/llvm/test/Transforms/MergeFunc/ptrauth-const-compare.ll
# executed command: /Users/oskarwirga/llvm-project/build/bin/opt -S -passes=mergefunc
# .---command stderr------------
# | Constant ValueID not recognized.
# | UNREACHABLE executed at /Users/oskarwirga/llvm-project/llvm/lib/Transforms/Utils/FunctionComparator.cpp:523!
# | PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace and instructions to reproduce the bug.
# | Stack dump:
# | 0.	Program arguments: /Users/oskarwirga/llvm-project/build/bin/opt -S -passes=mergefunc
# | 1.	Running pass "mergefunc" on module "<stdin>"
# |  #0 0x0000000103335770 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/Users/oskarwirga/llvm-project/build/bin/opt+0x102651770)
# |  #1 0x00000001033336bc llvm::sys::RunSignalHandlers() (/Users/oskarwirga/llvm-project/build/bin/opt+0x10264f6bc)
# |  #2 0x0000000103336218 SignalHandler(int, __siginfo*, void*) (/Users/oskarwirga/llvm-project/build/bin/opt+0x102652218)
# |  #3 0x000000018e6c16a4 (/usr/lib/system/libsystem_platform.dylib+0x1804ad6a4)
# |  #4 0x000000018e68788c (/usr/lib/system/libsystem_pthread.dylib+0x18047388c)
# |  #5 0x000000018e590a3c (/usr/lib/system/libsystem_c.dylib+0x18037ca3c)
# |  #6 0x00000001032a84bc llvm::install_out_of_memory_new_handler() (/Users/oskarwirga/llvm-project/build/bin/opt+0x1025c44bc)
# |  #7 0x00000001033b37c0 llvm::FunctionComparator::cmpMDNode(llvm::MDNode const*, llvm::MDNode const*) const (/Users/oskarwirga/llvm-project/build/bin/opt+0x1026cf7c0)
# |  #8 0x00000001033b4d90 llvm::FunctionComparator::cmpBasicBlocks(llvm::BasicBlock const*, llvm::BasicBlock const*) const (/Users/oskarwirga/llvm-project/build/bin/opt+0x1026d0d90)
# |  #9 0x00000001033b5234 llvm::FunctionComparator::compare() (/Users/oskarwirga/llvm-project/build/bin/opt+0x1026d1234)
# | #10 0x0000000102d6d868 (anonymous namespace)::MergeFunctions::insert(llvm::Function*) (/Users/oskarwirga/llvm-project/build/bin/opt+0x102089868)
# | #11 0x0000000102d6bc0c llvm::MergeFunctionsPass::runOnModule(llvm::Module&) (/Users/oskarwirga/llvm-project/build/bin/opt+0x102087c0c)
# | llvm#12 0x0000000102d6b430 llvm::MergeFunctionsPass::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/Users/oskarwirga/llvm-project/build/bin/opt+0x102087430)
# | llvm#13 0x0000000102b90558 llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/Users/oskarwirga/llvm-project/build/bin/opt+0x101eac558)
# | llvm#14 0x0000000103734bc4 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::__1::function<void (llvm::PassBuilder&)>>, llvm::opt_tool::OutputKind, llvm::opt_tool::VerifierKind, bool, bool, bool, bool, bool, bool, bool, bool) (/Users/oskarwirga/llvm-project/build/bin/opt+0x102a50bc4)
# | llvm#15 0x000000010373cc28 optMain (/Users/oskarwirga/llvm-project/build/bin/opt+0x102a58c28)
# | llvm#16 0x000000018e2e6b98
# `-----------------------------
# error: command failed with exit status: -6
# executed command: /Users/oskarwirga/llvm-project/build/bin/FileCheck /Users/oskarwirga/llvm-project/llvm/test/Transforms/MergeFunc/ptrauth-const-compare.ll
# .---command stderr------------
# | FileCheck error: '<stdin>' is empty.
# | FileCheck command line:  /Users/oskarwirga/llvm-project/build/bin/FileCheck /Users/oskarwirga/llvm-project/llvm/test/Transforms/MergeFunc/ptrauth-const-compare.ll
# `-----------------------------
# error: command failed with exit status: 2
```
EricWF pushed a commit that referenced this pull request Feb 9, 2026
…lvm#178069)

Kernel panic is a special case, and there is no signal or exception for
that so we need to rely on special workaround called `dumptid`.
FreeBSDKernel plugin is supposed to find this thread and set it manually
through `SetStopInfo()` in `CalculateStopInfo()` like Mach core plugin
does.

Before (We had to find and select crashed thread list otherwise thread 1
was selected by default):
```
➜ sudo lldb /boot/panic/kernel -c /var/crash/vmcore.last
(lldb) target create "/boot/panic/kernel" --core "/var/crash/vmcore.last"
Core file '/var/crash/vmcore.last' (x86_64) was loaded.
(lldb) bt
* thread #1, name = '(pid 12991) dtrace'
  * frame #0: 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff8015882f780, flags=259) at sched_ule.c:2448:26
    frame #1: 0xffffffff80bd38d2 kernel`mi_switch(flags=259) at kern_synch.c:530:2
    frame #2: 0xffffffff80c29799 kernel`sleepq_switch(wchan=0xfffff8014edff300, pri=0) at subr_sleepqueue.c:608:2
    frame #3: 0xffffffff80c29b76 kernel`sleepq_catch_signals(wchan=0xfffff8014edff300, pri=0) at subr_sleepqueue.c:523:3
    frame #4: 0xffffffff80c29d32 kernel`sleepq_timedwait_sig(wchan=<unavailable>, pri=<unavailable>) at subr_sleepqueue.c:704:11
    frame #5: 0xffffffff80bd2e2d kernel`_sleep(ident=0xfffff8014edff300, lock=0xffffffff81df2880, priority=768, wmesg="uwait", sbt=2573804118162, pr=0, flags=512) at kern_synch.c:215:10
    frame #6: 0xffffffff80be8622 kernel`umtxq_sleep(uq=0xfffff8014edff300, wmesg="uwait", timo=0xfffffe0279cb3d20) at kern_umtx.c:843:11
    frame #7: 0xffffffff80bef87a kernel`do_wait(td=0xfffff8015882f780, addr=<unavailable>, id=0, timeout=0xfffffe0279cb3d90, compat32=1, is_private=1) at kern_umtx.c:1316:12
    frame #8: 0xffffffff80bed264 kernel`__umtx_op_wait_uint_private(td=0xfffff8015882f780, uap=0xfffffe0279cb3dd8, ops=<unavailable>) at kern_umtx.c:3990:10
    frame #9: 0xffffffff80beaabe kernel`sys__umtx_op [inlined] kern__umtx_op(td=<unavailable>, obj=<unavailable>, op=<unavailable>, val=<unavailable>, uaddr1=<unavailable>, uaddr2=<unavailable>, ops=<unavailable>) at kern_umtx.c:4999:10
    frame #10: 0xffffffff80beaa89 kernel`sys__umtx_op(td=<unavailable>, uap=<unavailable>) at kern_umtx.c:5024:10
    frame #11: 0xffffffff81122cd1 kernel`amd64_syscall [inlined] syscallenter(td=0xfffff8015882f780) at subr_syscall.c:165:11
    frame llvm#12: 0xffffffff81122c19 kernel`amd64_syscall(td=0xfffff8015882f780, traced=0) at trap.c:1208:2
    frame llvm#13: 0xffffffff810f1dbb kernel`fast_syscall_common at exception.S:570
```

After:
```
➜ sudo ./build/bin/lldb /boot/panic/kernel -c /var/crash/vmcore.last
(lldb) target create "/boot/panic/kernel" --core "/var/crash/vmcore.last"
Core file '/var/crash/vmcore.last' (x86_64) was loaded.
(lldb) bt
* thread llvm#18, name = '(pid 5409) powerd (crashed)', stop reason = kernel panic
  * frame #0: 0xffffffff80bc6c91 kernel`__curthread at pcpu_aux.h:57:2 [inlined]
    frame #1: 0xffffffff80bc6c91 kernel`doadump(textdump=0) at kern_shutdown.c:399:2
    frame #2: 0xffffffff804b3b7a kernel`db_dump(dummy=<unavailable>, dummy2=<unavailable>, dummy3=<unavailable>, dummy4=<unavailable>) at db_command.c:596:10
    frame #3: 0xffffffff804b396d kernel`db_command(last_cmdp=<unavailable>, cmd_table=<unavailable>, dopager=true) at db_command.c:508:3
    frame #4: 0xffffffff804b362d kernel`db_command_loop at db_command.c:555:3
    frame #5: 0xffffffff804b7026 kernel`db_trap(type=<unavailable>, code=<unavailable>) at db_main.c:267:3
    frame #6: 0xffffffff80c16aaf kernel`kdb_trap(type=3, code=0, tf=0xfffffe01b605b930) at subr_kdb.c:790:13
    frame #7: 0xffffffff8112154e kernel`trap(frame=<unavailable>) at trap.c:614:8
    frame #8: 0xffffffff810f14c8 kernel`calltrap at exception.S:285
    frame #9: 0xffffffff81da2290 kernel`cn_devtab + 64
    frame #10: 0xfffffe01b605b8b0
    frame #11: 0xffffffff84001c43 dtrace.ko`dtrace_panic(format=<unavailable>) at dtrace.c:652:2
    frame llvm#12: 0xffffffff84005524 dtrace.ko`dtrace_action_panic(ecb=0xfffff80539cad580) at dtrace.c:7022:2 [inlined]
    frame llvm#13: 0xffffffff840054de dtrace.ko`dtrace_probe(id=88998, arg0=14343377283488, arg1=<unavailable>, arg2=<unavailable>, arg3=<unavailable>, arg4=<unavailable>) at dtrace.c:7665:6
    frame llvm#14: 0xffffffff83e5213d systrace.ko`systrace_probe(sa=<unavailable>, type=<unavailable>, retval=<unavailable>) at systrace.c:226:2
    frame llvm#15: 0xffffffff8112318d kernel`syscallenter(td=0xfffff801318d5780) at subr_syscall.c:160:4 [inlined]
    frame llvm#16: 0xffffffff81123112 kernel`amd64_syscall(td=0xfffff801318d5780, traced=0) at trap.c:1208:2
    frame llvm#17: 0xffffffff810f1dbb kernel`fast_syscall_common at exception.S:570
```
EricWF pushed a commit that referenced this pull request Feb 9, 2026
…8306)

In FreeBSD, allproc is a prepend list and new processes are appended at
head. This results in reverse pid order, so we first need to order pid
incrementally then print threads according to the correct order.

Before:
```
Process 0 stopped
* thread #1: tid = 101866, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff8015882f780, flags=259) at sched_ule.c:2448:26, name = '(pid 12991) dtrace'
  thread #2: tid = 101915, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff80158825780, flags=259) at sched_ule.c:2448:26, name = '(pid 11509) zsh'
  thread #3: tid = 101942, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff80142599000, flags=259) at sched_ule.c:2448:26, name = '(pid 11504) ftcleanup'
  thread #4: tid = 101545, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff80131898000, flags=259) at sched_ule.c:2448:26, name = '(pid 5599) zsh'
  thread #5: tid = 100905, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff80131899000, flags=259) at sched_ule.c:2448:26, name = '(pid 5598) sshd-session'
  thread #6: tid = 101693, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff8015886e780, flags=259) at sched_ule.c:2448:26, name = '(pid 5595) sshd-session'
  thread #7: tid = 101626, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff801588be000, flags=259) at sched_ule.c:2448:26, name = '(pid 5592) sh'
...
```

After:
```
(lldb) thread list
Process 0 stopped
* thread #1: tid = 100000, 0xffffffff80bf9322 kernel`sched_switch(td=0xffffffff81abe840, flags=259) at sched_ule.c:2448:26, name = '(pid 0) kernel'
  thread #2: tid = 100035, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff801052d9780, flags=259) at sched_ule.c:2448:26, name = '(pid 0) kernel/softirq_0'
  thread #3: tid = 100036, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff801052d9000, flags=259) at sched_ule.c:2448:26, name = '(pid 0) kernel/softirq_1'
  thread #4: tid = 100037, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff801052d8780, flags=259) at sched_ule.c:2448:26, name = '(pid 0) kernel/softirq_2'
  thread #5: tid = 100038, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff801052d8000, flags=259) at sched_ule.c:2448:26, name = '(pid 0) kernel/softirq_3'
  thread #6: tid = 100039, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff801052d7780, flags=259) at sched_ule.c:2448:26, name = '(pid 0) kernel/softirq_4'
  thread #7: tid = 100040, 0xffffffff80bf9322 kernel`sched_switch(td=0xfffff801052d7000, flags=259) at sched_ule.c:2448:26, name = '(pid 0) kernel/softirq_5'
...
```

Signed-off-by: Minsoo Choo <minsoochoo0122@proton.me>
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