[Mlir-commits] [mlir] [mlir][bytecode] Use getChecked<T>() in bytecode reading to avoid crashes (PR #186145)

[Kelvin Li]

kkwli wrote:

@joker-eph I have a question regarding `ArrayAttr` in `BuiltinDialectBytecode.td`. The comment in `BytecodeImplementation.h` states that for `ArrayAttr` `T::getChecked(emitError, context, params...)` will not be used. However, the definition of `ArrayAttr` leads to generate `getChecked` instead of `get<...>`. As a result, the following is generated in `BuiltinDialectBytecode.cpp.inc`,

```
static ::mlir::Attribute readArrayAttr(MLIRContext* context, DialectBytecodeReader &reader) {
  SmallVector<Attribute> value;
  if (succeeded(reader.readAttributes(value))) {
    return getChecked<ArrayAttr>([&]() { return reader.emitError(); }, context, value);
  }
  return ArrayAttr();
}
```

Is it expected? The reason I ask is that somehow our downstream compiler on AIX asserts with error:
`
Assertion failed: isInitialized() && "querying uninitialized conversion", file  clang/include/clang/Sema/Overload.h, line 716, Kind clang::ImplicitConversionSequence::getKind() const()
`

The following reproducer indicates that `getChecked<ArrayAttr>([&]() { return reader.emitError(); }, context, value)` has an issue.

```c++
#include "BuiltinDialectBytecode.h"
#include "AttributeDetail.h"
#include "mlir/Bytecode/BytecodeImplementation.h"

using namespace mlir;

namespace {

static ::mlir::Attribute readArrayAttr(MLIRContext* context, DialectBytecodeReader &reader) {
  SmallVector<Attribute> value;
  return getChecked<ArrayAttr>([&]() { return reader.emitError(); }, context, value);
}

} // namespace

```

I am not familiar with the code. Any insight or hint is much appreciated.

https://github.com/llvm/llvm-project/pull/186145