[clang] [CIR] Upstream initial attribute support (PR #121069)

[Erich Keane via cfe-commits]

================
@@ -21,18 +39,160 @@ using namespace cir;
 
 Attribute CIRDialect::parseAttribute(DialectAsmParser &parser,
                                      Type type) const {
-  // No attributes yet to parse
-  return Attribute{};
+  llvm::SMLoc typeLoc = parser.getCurrentLocation();
+  llvm::StringRef mnemonic;
+  Attribute genAttr;
+  OptionalParseResult parseResult =
+      generatedAttributeParser(parser, &mnemonic, type, genAttr);
+  if (parseResult.has_value())
+    return genAttr;
+  parser.emitError(typeLoc, "unknown attribute in CIR dialect");
+  return Attribute();
 }
 
 void CIRDialect::printAttribute(Attribute attr, DialectAsmPrinter &os) const {
-  // No attributes yet to print
+  if (failed(generatedAttributePrinter(attr, os)))
+    llvm_unreachable("unexpected CIR type kind");
+}
+
+//===----------------------------------------------------------------------===//
+// ConstPtrAttr definitions
+//===----------------------------------------------------------------------===//
+
+// TODO(CIR): Consider encoding the null value differently and use conditional
+// assembly format instead of custom parsing/printing.
+static ParseResult parseConstPtr(AsmParser &parser, mlir::IntegerAttr &value) {
+
+  if (parser.parseOptionalKeyword("null").succeeded()) {
+    value = mlir::IntegerAttr::get(
+        mlir::IntegerType::get(parser.getContext(), 64), 0);
+    return success();
+  }
+
+  return parser.parseAttribute(value);
+}
+
+static void printConstPtr(AsmPrinter &p, mlir::IntegerAttr value) {
+  if (!value.getInt())
+    p << "null";
+  else
+    p << value;
+}
+
+//===----------------------------------------------------------------------===//
+// IntAttr definitions
+//===----------------------------------------------------------------------===//
+
+Attribute IntAttr::parse(AsmParser &parser, Type odsType) {
+  mlir::APInt apValue;
+
+  if (!mlir::isa<IntType>(odsType))
+    return {};
+  auto type = mlir::cast<IntType>(odsType);
+
+  // Consume the '<' symbol.
+  if (parser.parseLess())
+    return {};
+
+  // Fetch arbitrary precision integer value.
+  if (type.isSigned()) {
+    int64_t value;
+    if (parser.parseInteger(value))
+      parser.emitError(parser.getCurrentLocation(), "expected integer value");
----------------
erichkeane wrote:

Makes sense, this LGTM.

https://github.com/llvm/llvm-project/pull/121069