Address comments

Author: matthias-springer

mlir/docs/DefiningDialects/AttributesAndTypes.md

@@ -1204,52 +1204,3 @@ void MyDialect::initialize() {
   >();
 }
 ```
-
-### Attribute / Type Constraints
-
-When defining the arguments of an operation in TableGen, users can specify
-either plain attributes/types or use attribute/type constraints to levy
-additional requirements on the attribute value or operand type.
-
-```tablegen
-def My_Type1 : MyDialect_Type<"Type1", "type1"> { ... }
-def My_Type2 : MyDialect_Type<"Type2", "type2"> { ... }
-
-// Plain type
-let arguments = (ins MyType1:$val);
-// Type constraint
-let arguments = (ins AnyTypeOf<[MyType1, MyType2]>:$val);
-```
-
-`AnyTypeOf` is an example for a type constraints. Many useful type constraints
-can be found in `mlir/IR/CommonTypeConstraints.td`. Additional verification
-code is generated for type/attribute constraints. Type constraints can not only
-be used when defining operation arguments, but also when defining type
-parameters.
-
-Optionally, C++ functions can be generated, so that type constraints can be
-checked from C++. The name of the C++ function must be specified in the
-`cppFunctionName` field. If no function name is specified, no C++ function is
-emitted.
-
-```tablegen
-// Example: Element type constraint for VectorType
-def Builtin_VectorTypeElementType : AnyTypeOf<[AnyInteger, Index, AnyFloat]> {
-  let cppFunctionName = "isValidVectorTypeElementType";
-}
-```
-
-An extra TableGen rule is needed to emit C++ code for type constraints. This
-will generate only the declarations/definitions of the type constaraints that
-are defined in the specified `.td` file, but not those that are in included
-`.td` files.
-
-```cmake
-mlir_tablegen(<Your Dialect>TypeConstraints.h.inc -gen-type-constraint-decls)
-mlir_tablegen(<Your Dialect>TypeConstraints.cpp.inc -gen-type-constraint-defs)
-```
-
-The generated `<Your Dialect>TypeConstraints.h.inc` will need to be included
-whereever you are referencing the type constraint in C++. Note that no C++
-namespace will be emitted by the code generator. The `#include` statements of
-the `.h.inc`/`.cpp.inc` files should be wrapped in C++ namespaces by the user.

mlir/docs/DefiningDialects/Constraints.md

@@ -0,0 +1,59 @@
+# Constraints
+
+[TOC]
+
+## Attribute / Type Constraints
+
+When defining the arguments of an operation in TableGen, users can specify
+either plain attributes/types or use attribute/type constraints to levy
+additional requirements on the attribute value or operand type.
+
+```tablegen
+def My_Type1 : MyDialect_Type<"Type1", "type1"> { ... }
+def My_Type2 : MyDialect_Type<"Type2", "type2"> { ... }
+
+// Plain type
+let arguments = (ins MyType1:$val);
+// Type constraint
+let arguments = (ins AnyTypeOf<[MyType1, MyType2]>:$val);
+```
+
+`AnyTypeOf` is an example for a type constraints. Many useful type constraints
+can be found in `mlir/IR/CommonTypeConstraints.td`. Additional verification
+code is generated for type/attribute constraints. Type constraints can not only
+be used when defining operation arguments, but also when defining type
+parameters.
+
+Optionally, C++ functions can be generated, so that type constraints can be
+checked from C++. The name of the C++ function must be specified in the
+`cppFunctionName` field. If no function name is specified, no C++ function is
+emitted.
+
+```tablegen
+// Example: Element type constraint for VectorType
+def Builtin_VectorTypeElementType : AnyTypeOf<[AnyInteger, Index, AnyFloat]> {
+  let cppFunctionName = "isValidVectorTypeElementType";
+}
+```
+
+The above example tranlates into the following C++ code:
+```c++
+bool isValidVectorTypeElementType(::mlir::Type type) {
+  return (((::llvm::isa<::mlir::IntegerType>(type))) || ((::llvm::isa<::mlir::IndexType>(type))) || ((::llvm::isa<::mlir::FloatType>(type))));
+}
+```
+
+An extra TableGen rule is needed to emit C++ code for type constraints. This
+will generate only the declarations/definitions of the type constaraints that
+are defined in the specified `.td` file, but not those that are in included
+`.td` files.
+
+```cmake
+mlir_tablegen(<Your Dialect>TypeConstraints.h.inc -gen-type-constraint-decls)
+mlir_tablegen(<Your Dialect>TypeConstraints.cpp.inc -gen-type-constraint-defs)
+```
+
+The generated `<Your Dialect>TypeConstraints.h.inc` will need to be included
+whereever you are referencing the type constraint in C++. Note that no C++
+namespace will be emitted by the code generator. The `#include` statements of
+the `.h.inc`/`.cpp.inc` files should be wrapped in C++ namespaces by the user.

mlir/tools/mlir-tblgen/AttrOrTypeDefGen.cpp

@@ -1027,16 +1027,6 @@ bool DefGenerator::emitDefs(StringRef selectedDialect) {
 // Type Constraints
 //===----------------------------------------------------------------------===//
 
-static const char *const typeConstraintDecl = R"(
-bool {0}(::mlir::Type type);
-)";
-
-static const char *const typeConstraintDef = R"(
-bool {0}(::mlir::Type type) {
-  return ({1});
-}
-)";
-
 /// Find all type constraints for which a C++ function should be generated.
 static std::vector<Constraint>
 getAllTypeConstraints(const llvm::RecordKeeper &records) {
@@ -1058,12 +1048,22 @@ getAllTypeConstraints(const llvm::RecordKeeper &records) {
 
 static void emitTypeConstraintDecls(const llvm::RecordKeeper &records,
                                     raw_ostream &os) {
+  static const char *const typeConstraintDecl = R"(
+bool {0}(::mlir::Type type);
+)";
+
   for (Constraint constr : getAllTypeConstraints(records))
     os << strfmt(typeConstraintDecl, *constr.getCppFunctionName());
 }
 
 static void emitTypeConstraintDefs(const llvm::RecordKeeper &records,
                                    raw_ostream &os) {
+  static const char *const typeConstraintDef = R"(
+bool {0}(::mlir::Type type) {
+  return ({1});
+}
+)";
+
   for (Constraint constr : getAllTypeConstraints(records)) {
     FmtContext ctx;
     ctx.withSelf("type");