[mlir] Make StringRefParameter roundtrippable

mlir/include/mlir/IR/AttrTypeBase.td

@@ -363,7 +363,7 @@ class DefaultValuedParameter<string type, string value, string desc = ""> :
 class StringRefParameter<string desc = "", string value = ""> :
     AttrOrTypeParameter<"::llvm::StringRef", desc> {
   let allocator = [{$_dst = $_allocator.copyInto($_self);}];
-  let printer = [{$_printer << '"' << $_self << '"';}];
+  let printer = [{$_printer.printString($_self);}];
   let cppStorageType = "std::string";
   let defaultValue = value;
 }

mlir/include/mlir/IR/OpImplementation.h

@@ -184,6 +184,10 @@ class AsmPrinter {
   /// has any special or non-printable characters in it.
   virtual void printKeywordOrString(StringRef keyword);
 
+  /// Print the given string as a quoted string, escaping any special or
+  /// non-printable characters in it.
+  virtual void printString(StringRef string);
+
   /// Print the given string as a symbol reference, i.e. a form representable by
   /// a SymbolRefAttr. A symbol reference is represented as a string prefixed
   /// with '@'. The reference is surrounded with ""'s and escaped if it has any

mlir/lib/IR/AsmPrinter.cpp

@@ -779,6 +779,7 @@ class DummyAliasOperationPrinter : private OpAsmPrinter {
     os << "%";
   }
   void printKeywordOrString(StringRef) override {}
+  void printString(StringRef) override {}
   void printResourceHandle(const AsmDialectResourceHandle &) override {}
   void printSymbolName(StringRef) override {}
   void printSuccessor(Block *) override {}
@@ -919,6 +920,7 @@ class DummyAliasDialectAsmPrinter : public DialectAsmPrinter {
   /// determining potential aliases.
   void printFloat(const APFloat &) override {}
   void printKeywordOrString(StringRef) override {}
+  void printString(StringRef) override {}
   void printSymbolName(StringRef) override {}
   void printResourceHandle(const AsmDialectResourceHandle &) override {}
 
@@ -2767,6 +2769,13 @@ void AsmPrinter::printKeywordOrString(StringRef keyword) {
   ::printKeywordOrString(keyword, impl->getStream());
 }
 
+void AsmPrinter::printString(StringRef keyword) {
+  assert(impl && "expected AsmPrinter::printString to be overriden");
+  *this << '"';
+  printEscapedString(keyword, getStream());
+  *this << '"';
+}
+
 void AsmPrinter::printSymbolName(StringRef symbolRef) {
   assert(impl && "expected AsmPrinter::printSymbolName to be overriden");
   ::printSymbolReference(symbolRef, impl->getStream());

mlir/test/mlir-tblgen/attr-or-type-format-roundtrip.mlir

@@ -70,6 +70,7 @@ attributes {
 // CHECK: !test.optional_type_string
 // CHECK: !test.optional_type_string
 // CHECK: !test.optional_type_string<"non default">
+// CHECK: !test.optional_type_string<"containing\0A \22escape\22 characters\0F">
 
 func.func private @test_roundtrip_default_parsers_struct(
   !test.no_parser<255, [1, 2, 3, 4, 5], "foobar", 4>
@@ -111,5 +112,6 @@ func.func private @test_roundtrip_default_parsers_struct(
   !test.custom_type_string<"bar" bar>,
   !test.optional_type_string,
   !test.optional_type_string<"default">,
-  !test.optional_type_string<"non default">
+  !test.optional_type_string<"non default">,
+  !test.optional_type_string<"containing\n \"escape\" characters\0f">
 )