Don't count attributes when addressing operands.

Fixes out-of-bound access in generated nested DAG rewriter matching code.

Reviewed By: tpopp

Differential Revision: https://reviews.llvm.org/D92075

mlir/test/mlir-tblgen/rewriter-indexing.td

@@ -0,0 +1,49 @@
+// RUN: mlir-tblgen -gen-rewriters -I %S/../../include %s | FileCheck %s
+
+include "mlir/IR/OpBase.td"
+
+def Test_Dialect : Dialect {
+  let name = "test";
+}
+class NS_Op<string mnemonic, list<OpTrait> traits> :
+    Op<Test_Dialect, mnemonic, traits>;
+
+def AOp : NS_Op<"a_op", []> {
+  let arguments = (ins
+    AnyInteger:$any_integer
+  );
+
+  let results = (outs AnyInteger);
+}
+
+def BOp : NS_Op<"b_op", []> {
+  let arguments = (ins
+    AnyAttr: $any_attr,
+    AnyInteger
+  );
+}
+
+// Tests dag operand indexing for ops with mixed attr and operand.
+// ---
+
+def COp : NS_Op<"c_op", []> {
+  let arguments = (ins
+    AnyAttr: $any_attr1,
+    AnyInteger,
+    AnyAttr: $any_attr2,
+    AnyInteger
+  );
+}
+
+// Only operand 0 should be addressed during matching.
+// CHECK: struct test1 : public ::mlir::RewritePattern {
+// CHECK: castedOp0.getODSOperands(0).begin()).getDefiningOp()
+def test1 : Pat<(BOp $attr, (AOp $input)),
+                (BOp $attr, $input)>;
+
+// Only operand 0 and 1 should be addressed during matching.
+// CHECK: struct test2 : public ::mlir::RewritePattern {
+// CHECK: castedOp0.getODSOperands(0);
+// CHECK: castedOp0.getODSOperands(1).begin()).getDefiningOp()
+def test2 : Pat<(COp $attr1, $op1, $attr2, (AOp $op2)),
+                (BOp $attr1, $op2)>;

mlir/tools/mlir-tblgen/RewriterGen.cpp

@@ -349,7 +349,7 @@ void PatternEmitter::emitOpMatch(DagNode tree, StringRef opName, int depth) {
   if (!name.empty())
     os << formatv("{0} = {1};\n", name, castedName);
 
-  for (int i = 0, e = tree.getNumArgs(); i != e; ++i) {
+  for (int i = 0, e = tree.getNumArgs(), nextOperand = 0; i != e; ++i) {
     auto opArg = op.getArg(i);
     std::string argName = formatv("op{0}", depth + 1);
 
@@ -365,10 +365,11 @@ void PatternEmitter::emitOpMatch(DagNode tree, StringRef opName, int depth) {
       }
       os << "{\n";
 
+      // Attributes don't count for getODSOperands.
       os.indent() << formatv(
           "auto *{0} = "
           "(*{1}.getODSOperands({2}).begin()).getDefiningOp();\n",
-          argName, castedName, i);
+          argName, castedName, nextOperand++);
       emitMatch(argTree, argName, depth + 1);
       os << formatv("tblgen_ops[{0}] = {1};\n", ++opCounter, argName);
       os.unindent() << "}\n";
@@ -377,7 +378,9 @@ void PatternEmitter::emitOpMatch(DagNode tree, StringRef opName, int depth) {
 
     // Next handle DAG leaf: operand or attribute
     if (opArg.is<NamedTypeConstraint *>()) {
+      // emitOperandMatch's argument indexing counts attributes.
       emitOperandMatch(tree, castedName, i, depth);
+      ++nextOperand;
     } else if (opArg.is<NamedAttribute *>()) {
       emitAttributeMatch(tree, opName, i, depth);
     } else {