refactor: check for buffer validity and emit errors instead of match failures

Author: maxbartel

mlir/lib/Conversion/ArithToSPIRV/ArithToSPIRV.cpp

@@ -230,8 +230,10 @@ struct ConstantCompositeOpPattern final
     if (!srcType || srcType.getNumElements() == 1)
       return failure();
 
-    // arith.constant should only have vector or tensor types.
-    assert((isa<VectorType, RankedTensorType>(srcType)));
+    // arith.constant should only have vector or tensor types. This is a MLIR
+    // wide problem at the moment.
+    if (!isa<VectorType, RankedTensorType>(srcType))
+      return rewriter.notifyMatchFailure(constOp, "unsupported ShapedType");
 
     Type dstType = getTypeConverter()->convertType(srcType);
     if (!dstType)
@@ -246,12 +248,22 @@ struct ConstantCompositeOpPattern final
     } else if (auto resourceAttr =
                    dyn_cast<DenseResourceElementsAttr>(constOp.getValue())) {
 
-      ArrayRef<char> ptr = resourceAttr.getRawHandle().getBlob()->getData();
+      AsmResourceBlob *blob = resourceAttr.getRawHandle().getBlob();
+      if (!blob)
+        return constOp->emitError("could not find resource blob");
+
+      ArrayRef<char> ptr = blob->getData();
+
+      // Check that the buffer meets the requirements to get converted to a
+      // DenseElementsAttr
+      bool detectedSplat = false;
+      if (!DenseElementsAttr::isValidRawBuffer(srcType, ptr, detectedSplat))
+        return constOp->emitError("resource is not a valid buffer");
+
       dstElementsAttr =
           DenseElementsAttr::getFromRawBuffer(resourceAttr.getType(), ptr);
     } else {
-      return rewriter.notifyMatchFailure(constOp,
-                                         "Could not decode ElementsAttr");
+      return constOp->emitError("unsupported elements attribute");
     }
 
     ShapedType dstAttrType = dstElementsAttr.getType();

mlir/test/Conversion/ArithToSPIRV/arith-to-spirv-unsupported.mlir

@@ -95,6 +95,34 @@ func.func @unsupported_constant_tensor_2xf64_0() {
   return
 }
 
+// -----
+
+func.func @constant_dense_resource_non_existant() {
+  // expected-error @+2 {{failed to legalize operation 'arith.constant'}}
+  // expected-error @+1 {{could not find resource blob}}
+  %0 = arith.constant dense_resource<non_existant> : tensor<5xf32>  
+  return
+}
+
+// -----
+
+module {
+func.func @constant_dense_resource_invalid_buffer() {
+  // expected-error @+2 {{failed to legalize operation 'arith.constant'}}
+  // expected-error @+1 {{resource is not a valid buffer}}
+  %0 = arith.constant dense_resource<dense_resource_test_2xi32> : vector<2xi32>  
+  return
+  }
+}
+// This is a buffer of wrong type and shape
+{-#
+  dialect_resources: {
+    builtin: {
+      dense_resource_test_2xi32: "0x0800000054A3B53ED6C0B33E55D1A2BDE5D2BB3E"
+    }
+  }
+#-}
+
 ///===----------------------------------------------------------------------===//
 // Type emulation
 //===----------------------------------------------------------------------===//