[Mlir-commits] [mlir] [mlir][func] Account for named attributes without a dialect prefix in `FuncToLLVM` lowering pass (PR #182987)

[Mehdi Amini]

================
@@ -52,10 +52,15 @@ static constexpr StringRef varargsAttrName = "func.varargs";
 static constexpr StringRef linkageAttrName = "llvm.linkage";
 static constexpr StringRef barePtrAttrName = "llvm.bareptr";
 
+static constexpr StringRef varargsAttrNameNoPrefix = "varargs";
+static constexpr StringRef linkageAttrNameNoPrefix = "linkage";
+static constexpr StringRef barePtrAttrNameNoPrefix = "bareptr";
+
 /// Return `true` if the `op` should use bare pointer calling convention.
 static bool shouldUseBarePtrCallConv(Operation *op,
                                      const LLVMTypeConverter *typeConverter) {
-  return (op && op->hasAttr(barePtrAttrName)) ||
+  return (op && (op->hasAttr(barePtrAttrName) ||
+                 op->hasAttr(barePtrAttrNameNoPrefix))) ||
----------------
joker-eph wrote:

Yes the design is messy. 
This part is already hardcoding some of the LLVM func op attributes in a way that is really not good:

```
/// Only retain those attributes that are not constructed by
/// `LLVMFuncOp::build`.
static void filterFuncAttributes(FunctionOpInterface func,
                                 SmallVectorImpl<NamedAttribute> &result) {
  for (const NamedAttribute &attr : func->getDiscardableAttrs()) {
    if (attr.getName() == linkageAttrName ||
        attr.getName() == varargsAttrName ||
        attr.getName() == LLVM::LLVMDialect::getReadnoneAttrName())
      continue;
    result.push_back(attr);
  }
}
```

> I do not know of any mechanism to enumerate all ODS-defined attribute names

Actually there is: `  static ::llvm::ArrayRef<::llvm::StringRef> getAttributeNames() {`.
We could update the `filterFuncAttributes` to use `LLVMFuncOp::getAttributeNames()` instead of these three hardcoded names?


https://github.com/llvm/llvm-project/pull/182987