Fixed verification checks for character and DIM constants.

Author: vzakhari

flang/lib/Optimizer/HLFIR/IR/HLFIROps.cpp

@@ -1360,8 +1360,21 @@ llvm::LogicalResult hlfir::CShiftOp::verify() {
   mlir::Type shiftTy = hlfir::getFortranElementOrSequenceType(shift.getType());
 
   if (eleTy != resultEleTy)
-    return emitOpError(
-        "input and output arrays should have the same element type");
+    if (mlir::isa<fir::CharacterType>(eleTy) &&
+        mlir::isa<fir::CharacterType>(resultEleTy)) {
+      auto eleCharTy = mlir::cast<fir::CharacterType>(eleTy);
+      auto resultCharTy = mlir::cast<fir::CharacterType>(resultEleTy);
+      if (eleCharTy.getFKind() != resultCharTy.getFKind())
+        return emitOpError("kind mismatch between input and output arrays");
+      if (eleCharTy.getLen() != fir::CharacterType::unknownLen() &&
+          resultCharTy.getLen() != fir::CharacterType::unknownLen() &&
+          eleCharTy.getLen() != resultCharTy.getLen())
+        return emitOpError(
+            "character LEN mismatch between input and output arrays");
+    } else {
+      return emitOpError(
+          "input and output arrays should have the same element type");
+    }
 
   if (arrayRank != resultRank)
     return emitOpError("input and output arrays should have the same rank");
@@ -1379,7 +1392,10 @@ llvm::LogicalResult hlfir::CShiftOp::verify() {
   else if (auto dim = fir::getIntIfConstant(getDim()))
     dimVal = *dim;
 
-  if (dimVal != -1) {
+  // The DIM argument may be statically invalid (e.g. exceed the
+  // input array rank) in dead code after constant propagation,
+  // so avoid some checks unless useStrictIntrinsicVerifier is true.
+  if (useStrictIntrinsicVerifier && dimVal != -1) {
     if (dimVal < 1)
       return emitOpError("DIM must be >= 1");
     if (dimVal > static_cast<int64_t>(arrayRank))
@@ -1394,7 +1410,7 @@ llvm::LogicalResult hlfir::CShiftOp::verify() {
       return emitOpError(
           "SHIFT's rank must be 1 less than the input array's rank");
 
-    if (dimVal != -1) {
+    if (useStrictIntrinsicVerifier && dimVal != -1) {
       // SHIFT's shape must be [d(1), d(2), ..., d(DIM-1), d(DIM+1), ..., d(n)],
       // where [d(1), d(2), ..., d(n)] is the shape of the ARRAY.
       int64_t arrayDimIdx = 0;

flang/test/HLFIR/invalid.fir

@@ -1407,3 +1407,19 @@ func.func @bad_cshift7(%arg0: !hlfir.expr<?x2xi32>, %arg1: !hlfir.expr<3xi32>) {
   %0 = hlfir.cshift %arg0 %arg1 dim %c1 : (!hlfir.expr<?x2xi32>, !hlfir.expr<3xi32>, index) -> !hlfir.expr<2x2xi32>
   return
 }
+
+// -----
+
+func.func @bad_cshift8(%arg0: !hlfir.expr<?x!fir.char<1,?>>, %arg1: i32) {
+  // expected-error@+1 {{'hlfir.cshift' op kind mismatch between input and output arrays}}
+  %0 = hlfir.cshift %arg0 %arg1 : (!hlfir.expr<?x!fir.char<1,?>>, i32) -> !hlfir.expr<?x!fir.char<2,?>>
+  return
+}
+
+// -----
+
+func.func @bad_cshift9(%arg0: !hlfir.expr<?x!fir.char<1,1>>, %arg1: i32) {
+  // expected-error@+1 {{'hlfir.cshift' op character LEN mismatch between input and output arrays}}
+  %0 = hlfir.cshift %arg0 %arg1 : (!hlfir.expr<?x!fir.char<1,1>>, i32) -> !hlfir.expr<?x!fir.char<1,2>>
+  return
+}