[Mlir-commits] [mlir] [mlir] Improve error message when number of operands and types differ (PR #118488)

[Markus Böck]

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@@ -1602,14 +1602,33 @@ class OpAsmParser : public AsmParser {
                   SmallVectorImpl<Value> &result) {
     size_t operandSize = llvm::range_size(operands);
     size_t typeSize = llvm::range_size(types);
-    if (operandSize != typeSize)
-      return emitError(loc)
-             << operandSize << " operands present, but expected " << typeSize;
+    if (operandSize == typeSize) {
+      for (auto [operand, type] : llvm::zip_equal(operands, types))
+        if (resolveOperand(operand, type, result))
+          return failure();
+      return success();
+    }
 
-    for (auto [operand, type] : llvm::zip_equal(operands, types))
-      if (resolveOperand(operand, type, result))
-        return failure();
-    return success();
+    InFlightDiagnostic diag = emitError(loc)
+                              << "number of operands and types do not match";
+    std::string lesserQuantityText = "operand";
+    if (operandSize != 1)
+      lesserQuantityText += "s";
+    std::string higherQuantityText = "type";
+    if (typeSize != 1)
+      higherQuantityText += "s";
+
+    size_t lesserQuantity = operandSize;
+    size_t higherQuantity = typeSize;
+    if (operandSize > typeSize) {
+      std::swap(lesserQuantity, higherQuantity);
+      std::swap(lesserQuantityText, higherQuantityText);
+    }
+
+    diag.attachNote() << "got " << higherQuantity << " " << higherQuantityText
+                      << " but only " << lesserQuantity << " "
+                      << lesserQuantityText;
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zero9178 wrote:

I don't feel super strong about either options, so if you feel the current version is worse or not worth the extra implementation complexity I can gladly change it! 

https://github.com/llvm/llvm-project/pull/118488