[mlir] Make MLIRContext::getOrLoadDialect(StringRef, TypeID, ...) public

[math-fehr]

Summary

Having this function in a public scope is helpful to register dialects that are
defined at runtime, and thus that need a runtime-defined TypeID.

Also, a similar function in DialectRegistry, insert(TypeID, StringRef, ...), has
a public scope.

[mehdi_amini]

mlir/include/mlir/IR/MLIRContext.h

163–165

Can you document that the use of this method is discouraged in favor of getOrLoadDialect<DialectClass>() ?

[math-fehr]

Add comment explaining that the use of the method is discouraged for most of the cases.

[mehdi_amini]

Do you need me to land this for you?

[math-fehr]

Oh yes sorry I forgot to mention that! I'll remember next time.
Thanks!

mlir/include/mlir/IR/MLIRContext.h

public:
   StorageUniquer &getAttributeUniquer();
 
   /// These APIs are tracking whether the context will be used in a
   /// multithreading environment: this has no effect other than enabling
   /// assertions on misuses of some APIs.
   void enterMultiThreadedExecution();
   void exitMultiThreadedExecution();
 
-private:
-  const std::unique_ptr<MLIRContextImpl> impl;
-
   /// Get a dialect for the provided namespace and TypeID: abort the program if
   /// a dialect exist for this namespace with different TypeID. If a dialect has
   /// not been loaded for this namespace/TypeID yet, use the provided ctor to
   /// create one on the fly and load it. Returns a pointer to the dialect owned
   /// by the context.
+  /// The use of this method is in general discouraged in favor of
+  /// 'getOrLoadDialect<DialectClass>()'.
   Dialect *getOrLoadDialect(StringRef dialectNamespace, TypeID dialectID,
                             function_ref<std::unique_ptr<Dialect>()> ctor);
 
+private:
+  const std::unique_ptr<MLIRContextImpl> impl;
+
   MLIRContext(const MLIRContext &) = delete;
   void operator=(const MLIRContext &) = delete;
 };
 
 //===----------------------------------------------------------------------===//
 // MLIRContext CommandLine Options
 //===----------------------------------------------------------------------===//
 
 /// Register a set of useful command-line options that can be used to configure
 /// various flags within the MLIRContext. These flags are used when constructing
 /// an MLIR context for initialization.
 void registerMLIRContextCLOptions();
 
 } // end namespace mlir
 
 #endif // MLIR_IR_MLIRCONTEXT_H