[mlir] Revert "Tighten access of RewritePattern methods."

This reverts commit 02c9050155.
Painted myself into a corner with -Wvirtual_overload, private access, and final.

Differential Revision: https://reviews.llvm.org/D92855

mlir/include/mlir/Conversion/StandardToLLVM/ConvertStandardToLLVM.h

@@ -571,9 +571,11 @@ public:
                              &typeConverter.getContext(), typeConverter,
                              benefit) {}
 
-private:
-  /// Wrappers around the ConversionPattern methods that pass the derived op
-  /// type.
+  /// Wrappers around the RewritePattern methods that pass the derived op type.
+  void rewrite(Operation *op, ArrayRef<Value> operands,
+               ConversionPatternRewriter &rewriter) const final {
+    rewrite(cast<SourceOp>(op), operands, rewriter);
+  }
   LogicalResult match(Operation *op) const final {
     return match(cast<SourceOp>(op));
   }
@@ -582,10 +584,6 @@ private:
                   ConversionPatternRewriter &rewriter) const final {
     return matchAndRewrite(cast<SourceOp>(op), operands, rewriter);
   }
-  void rewrite(Operation *op, ArrayRef<Value> operands,
-               ConversionPatternRewriter &rewriter) const final {
-    rewrite(cast<SourceOp>(op), operands, rewriter);
-  }
 
   /// Rewrite and Match methods that operate on the SourceOp type. These must be
   /// overridden by the derived pattern class.
@@ -605,6 +603,10 @@ private:
     }
     return failure();
   }
+
+private:
+  using ConvertToLLVMPattern::match;
+  using ConvertToLLVMPattern::matchAndRewrite;
 };
 
 namespace LLVM {
@@ -634,7 +636,6 @@ public:
   using ConvertOpToLLVMPattern<SourceOp>::ConvertOpToLLVMPattern;
   using Super = OneToOneConvertToLLVMPattern<SourceOp, TargetOp>;
 
-private:
   /// Converts the type of the result to an LLVM type, pass operands as is,
   /// preserve attributes.
   LogicalResult
@@ -654,7 +655,6 @@ public:
   using ConvertOpToLLVMPattern<SourceOp>::ConvertOpToLLVMPattern;
   using Super = VectorConvertToLLVMPattern<SourceOp, TargetOp>;
 
-private:
   LogicalResult
   matchAndRewrite(SourceOp op, ArrayRef<Value> operands,
                   ConversionPatternRewriter &rewriter) const override {

mlir/include/mlir/IR/PatternMatch.h

@@ -156,6 +156,17 @@ class RewritePattern : public Pattern {
 public:
   virtual ~RewritePattern() {}
 
+  /// Rewrite the IR rooted at the specified operation with the result of
+  /// this pattern, generating any new operations with the specified
+  /// builder.  If an unexpected error is encountered (an internal
+  /// compiler error), it is emitted through the normal MLIR diagnostic
+  /// hooks and the IR is left in a valid state.
+  virtual void rewrite(Operation *op, PatternRewriter &rewriter) const;
+
+  /// Attempt to match against code rooted at the specified operation,
+  /// which is the same operation code as getRootKind().
+  virtual LogicalResult match(Operation *op) const;
+
   /// Attempt to match against code rooted at the specified operation,
   /// which is the same operation code as getRootKind(). If successful, this
   /// function will automatically perform the rewrite.
@@ -172,18 +183,6 @@ protected:
   /// Inherit the base constructors from `Pattern`.
   using Pattern::Pattern;
 
-  /// Attempt to match against code rooted at the specified operation,
-  /// which is the same operation code as getRootKind().
-  virtual LogicalResult match(Operation *op) const;
-
-private:
-  /// Rewrite the IR rooted at the specified operation with the result of
-  /// this pattern, generating any new operations with the specified
-  /// builder.  If an unexpected error is encountered (an internal
-  /// compiler error), it is emitted through the normal MLIR diagnostic
-  /// hooks and the IR is left in a valid state.
-  virtual void rewrite(Operation *op, PatternRewriter &rewriter) const;
-
   /// An anchor for the virtual table.
   virtual void anchor();
 };
@@ -192,14 +191,12 @@ private:
 /// matching and rewriting against an instance of a derived operation class as
 /// opposed to a raw Operation.
 template <typename SourceOp>
-class OpRewritePattern : public RewritePattern {
-public:
+struct OpRewritePattern : public RewritePattern {
   /// Patterns must specify the root operation name they match against, and can
   /// also specify the benefit of the pattern matching.
   OpRewritePattern(MLIRContext *context, PatternBenefit benefit = 1)
       : RewritePattern(SourceOp::getOperationName(), benefit, context) {}
 
-private:
   /// Wrappers around the RewritePattern methods that pass the derived op type.
   void rewrite(Operation *op, PatternRewriter &rewriter) const final {
     rewrite(cast<SourceOp>(op), rewriter);

mlir/include/mlir/Transforms/DialectConversion.h

@@ -313,6 +313,30 @@ private:
 /// patterns of this type can only be used with the 'apply*' methods below.
 class ConversionPattern : public RewritePattern {
 public:
+  /// Hook for derived classes to implement rewriting. `op` is the (first)
+  /// operation matched by the pattern, `operands` is a list of the rewritten
+  /// operand values that are passed to `op`, `rewriter` can be used to emit the
+  /// new operations. This function should not fail. If some specific cases of
+  /// the operation are not supported, these cases should not be matched.
+  virtual void rewrite(Operation *op, ArrayRef<Value> operands,
+                       ConversionPatternRewriter &rewriter) const {
+    llvm_unreachable("unimplemented rewrite");
+  }
+
+  /// Hook for derived classes to implement combined matching and rewriting.
+  virtual LogicalResult
+  matchAndRewrite(Operation *op, ArrayRef<Value> operands,
+                  ConversionPatternRewriter &rewriter) const {
+    if (failed(match(op)))
+      return failure();
+    rewrite(op, operands, rewriter);
+    return success();
+  }
+
+  /// Attempt to match and rewrite the IR root at the specified operation.
+  LogicalResult matchAndRewrite(Operation *op,
+                                PatternRewriter &rewriter) const final;
+
   /// Return the type converter held by this pattern, or nullptr if the pattern
   /// does not require type conversion.
   TypeConverter *getTypeConverter() const { return typeConverter; }
@@ -336,46 +360,19 @@ protected:
                     MatchAnyOpTypeTag tag)
       : RewritePattern(benefit, tag), typeConverter(&typeConverter) {}
 
-private:
-  /// Hook for derived classes to implement rewriting. `op` is the (first)
-  /// operation matched by the pattern, `operands` is a list of the rewritten
-  /// operand values that are passed to `op`, `rewriter` can be used to emit the
-  /// new operations. This function should not fail. If some specific cases of
-  /// the operation are not supported, these cases should not be matched.
-  virtual void rewrite(Operation *op, ArrayRef<Value> operands,
-                       ConversionPatternRewriter &rewriter) const {
-    llvm_unreachable("unimplemented rewrite");
-  }
-
-  void rewrite(Operation *op, PatternRewriter &rewriter) const final {
-    llvm_unreachable("never called");
-  }
-
-  /// Hook for derived classes to implement combined matching and rewriting.
-  virtual LogicalResult
-  matchAndRewrite(Operation *op, ArrayRef<Value> operands,
-                  ConversionPatternRewriter &rewriter) const {
-    if (failed(match(op)))
-      return failure();
-    rewrite(op, operands, rewriter);
-    return success();
-  }
-
-  /// Attempt to match and rewrite the IR root at the specified operation.
-  LogicalResult matchAndRewrite(Operation *op,
-                                PatternRewriter &rewriter) const final;
-
 protected:
   /// An optional type converter for use by this pattern.
   TypeConverter *typeConverter = nullptr;
+
+private:
+  using RewritePattern::rewrite;
 };
 
 /// OpConversionPattern is a wrapper around ConversionPattern that allows for
 /// matching and rewriting against an instance of a derived operation class as
 /// opposed to a raw Operation.
 template <typename SourceOp>
-class OpConversionPattern : public ConversionPattern {
-public:
+struct OpConversionPattern : public ConversionPattern {
   OpConversionPattern(MLIRContext *context, PatternBenefit benefit = 1)
       : ConversionPattern(SourceOp::getOperationName(), benefit, context) {}
   OpConversionPattern(TypeConverter &typeConverter, MLIRContext *context,
@@ -383,7 +380,6 @@ public:
       : ConversionPattern(SourceOp::getOperationName(), benefit, typeConverter,
                           context) {}
 
-private:
   /// Wrappers around the ConversionPattern methods that pass the derived op
   /// type.
   void rewrite(Operation *op, ArrayRef<Value> operands,
@@ -413,6 +409,9 @@ private:
     rewrite(op, operands, rewriter);
     return success();
   }
+
+private:
+  using ConversionPattern::matchAndRewrite;
 };
 
 /// Add a pattern to the given pattern list to convert the signature of a FuncOp