[Mlir-commits] [flang] [mlir] [mlir][func] Refactor FuncToLLVM discardable attributes algorithm (PR #188232)

[Hocky Yudhiono]

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@@ -59,19 +68,114 @@ static bool shouldUseBarePtrCallConv(Operation *op,
          typeConverter->getOptions().useBarePtrCallConv;
 }
 
+static bool isDiscardableAttr(StringRef name) {
+  return name == linkageAttrName || name == varargsAttrName ||
+         name == LLVM::LLVMDialect::getReadnoneAttrName();
+}
+
 /// 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())
+    if (isDiscardableAttr(attr.getName().strref()))
       continue;
     result.push_back(attr);
   }
 }
 
+/// Add custom lowered funcOp to llvm.func attributes here.
+struct LoweredFuncAttrs {
+  LLVM::Linkage linkage = LLVM::Linkage::External;
+  bool hasReadnone = false;
+  SmallVector<NamedAttribute, 4> attrs;
+};
+
+static LogicalResult lowerLinkageAttr(FunctionOpInterface func,
+                                      Attribute attrValue,
+                                      LoweredFuncAttrs &lowered) {
+  auto linkageAttr = dyn_cast<mlir::LLVM::LinkageAttr>(attrValue);
+  if (!linkageAttr) {
+    func->emitError() << "Contains " << linkageAttrName
+                      << " attribute not of type LLVM::LinkageAttr";
+    return failure();
+  }
+  lowered.linkage = linkageAttr.getLinkage();
+  return success();
+}
+
+static LogicalResult lowerReadnoneAttr(FunctionOpInterface func,
+                                       Attribute attrValue,
+                                       LoweredFuncAttrs &lowered) {
+  StringRef readnoneAttrName = LLVM::LLVMDialect::getReadnoneAttrName();
+  if (!isa<UnitAttr>(attrValue)) {
+    func->emitError() << "Contains " << readnoneAttrName
+                      << " attribute not of type UnitAttr";
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hockyy wrote:

Refactored this function, I'm returning a failure in the call site.

https://github.com/llvm/llvm-project/pull/188232