When generating C++ code, use C++ string escaping.

[jpienaar]

Could you add a test where this difference let to a bug that could be used for regression testing?

[rdzhabarov]

I also see similar method used here and there across the codebase. Might be good to expose this as a utility method and reuse.

[Mogball]

Yeah, I agree. You can probably move this to mlir/TableGen/CodeGenHelpers.h and unify it with the other version in RewriterGen.cpp.

[matthiaskramm]

Thanks for the quick review!

Moved escapeString() into CodeGenHelpers.cpp, and added a test.

[matthiaskramm]

Adjust commit description.

[Mogball]

mlir/tools/mlir-tblgen/CodeGenHelpers.cpp

141–149

Function definitions shouldn't be enclosed in namespaces.

[matthiaskramm]

Fold namespaces into prototype.

[matthiaskramm]

Make opL test case slightly more realistic.

[Mogball]

Thanks

mlir/include/mlir/TableGen/CodeGenHelpers.h

private:
   /// ensure that the local functions have a unique name.
   std::string uniqueOutputLabel;
 
   /// A set of functions implementing type constraints, used for operand and
   /// result verification.
   llvm::DenseMap<const void *, std::string> localTypeConstraints;
 };
 
+// Escape a string using C++ encoding. E.g. foo"bar -> foo\x22bar.
+std::string escapeString(StringRef value);
+
 } // namespace tblgen
 } // namespace mlir
 
 #endif // MLIR_TABLEGEN_CODEGENHELPERS_H

mlir/test/mlir-tblgen/predicate.td

 def OpK : NS_Op<"op_for_AnyTensorOf", []> {
   let arguments = (ins TensorOf<[F32, I32]>:$x);
 }
 
 // CHECK-LABEL: OpK::verify
 // CHECK: auto valueGroup0 = getODSOperands(0);
 // CHECK: for (::mlir::Value v : valueGroup0) {
 // CHECK: if (::mlir::failed([[$TENSOR_INTEGER_FLOAT_CONSTRAINT]]
+
+def OpL : NS_Op<"op_for_StringEscaping", []> {
+  let arguments = (ins
+    StringBasedAttr<CPred<"$_self.cast<StringAttr>().getValue() == \"foo\"">,
+                    "only value \"foo\" is allowed">:$s
+  );
+}
+
+// CHECK-LABEL: OpLAdaptor::verify
+// CHECK: getValue() == "foo"
+// CHECK-SAME: only value \"foo\" is allowed

mlir/tools/mlir-tblgen/CodeGenHelpers.cpp

os.indent() << "if (!("
                 << ")) {\n";
     os.indent() << "return "
                 << formatv(errorHandlerFormat.data(), constraint.getSummary())
                 << ";\n";
     os.unindent() << "}\nreturn ::mlir::success();\n";
     os.unindent() << "}\n\n";
   }
 }
+
+std::string mlir::tblgen::escapeString(StringRef value) {
+  std::string ret;
+  llvm::raw_string_ostream os(ret);
+  os.write_escaped(value);
+  return os.str();
+}

mlir/tools/mlir-tblgen/OpDefinitionsGen.cpp

static std::string replaceAllSubstrs(std::string str, const std::string &match,
   std::string::size_type scanLoc = 0, matchLoc = std::string::npos;
   while ((matchLoc = str.find(match, scanLoc)) != std::string::npos) {
     str = str.replace(matchLoc, match.size(), substitute);
     scanLoc = matchLoc + substitute.size();
   }
   return str;
 }
 
-// Escape a string using LLVM/MLIR encoding. E.g. foo"bar -> foo\22bar.
-static std::string escapeString(StringRef value) {
-  std::string ret;
-  llvm::raw_string_ostream os(ret);
-  llvm::printEscapedString(value, os);
-  return os.str();
-}
-
 // Returns whether the record has a value of the given name that can be returned
 // via getValueAsString.
 static inline bool hasStringAttribute(const Record &record,
                                       StringRef fieldName) {
   auto valueInit = record.getValueInit(fieldName);
   return isa<StringInit>(valueInit);
 }
 

mlir/tools/mlir-tblgen/RewriterGen.cpp

 //===- RewriterGen.cpp - MLIR pattern rewriter generator ------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // RewriterGen uses pattern rewrite definitions to generate rewriter matchers.
 //
 //===----------------------------------------------------------------------===//
 
 #include "mlir/Support/IndentedOstream.h"
 #include "mlir/TableGen/Attribute.h"
+#include "mlir/TableGen/CodeGenHelpers.h"
 #include "mlir/TableGen/Format.h"
 #include "mlir/TableGen/GenInfo.h"
 #include "mlir/TableGen/Operator.h"
 #include "mlir/TableGen/Pattern.h"
 #include "mlir/TableGen/Predicate.h"
 #include "mlir/TableGen/Type.h"
 #include "llvm/ADT/FunctionExtras.h"
 #include "llvm/ADT/StringExtras.h"

 struct format_provider<mlir::tblgen::Pattern::IdentifierLine> {
   static void format(const mlir::tblgen::Pattern::IdentifierLine &v,
                      raw_ostream &os, StringRef style) {
     os << v.first << ":" << v.second;
   }
 };
 } // end namespace llvm
 
-// Escape a string for use inside a C++ literal.
-// E.g. foo"bar -> foo\x22bar.
-static std::string escapeString(StringRef value) {
-  std::string ret;
-  llvm::raw_string_ostream os(ret);
-  os.write_escaped(value, /*use_hex_escapes=*/true);
-  return os.str();
-}
-
 //===----------------------------------------------------------------------===//
 // PatternEmitter
 //===----------------------------------------------------------------------===//
 
 namespace {
 
 class StaticMatcherHelper;