refine some messages and adjust data type

paddle/fluid/operators/squeeze_op.cc

@@ -30,13 +30,14 @@ class SqueezeOpInferShape : public framework::InferShapeBase {
     const auto &x_dims = ctx->GetInputDim("X");
     // Check input tensor dims (<6) Eigen limit.
     PADDLE_ENFORCE(x_dims.size() <= 6,
-                   "Invalid dimnesions, dynamic dimensions must have "
-                   "between [1, 6] dimensions (Eigen limit).");
+                   "Invalid dimnesions, the rank of Input(X) "
+                   "should be in the range of [1, 6] (Eigen limit).");
 
     const auto &axes = ctx->Attrs().Get<std::vector<int>>("axes");
     for (int a : axes) {
       PADDLE_ENFORCE_LT(a, x_dims.size(),
-                        "The axis must be less than input tensor's rank.");
+                        "The squeeze axis should be less than input "
+                        "tensor's rank.");
     }
 
     auto out_dims = GetOutputShape(axes, x_dims);
@@ -50,30 +51,29 @@ class SqueezeOpInferShape : public framework::InferShapeBase {
 
   static framework::DDim GetOutputShape(const std::vector<int> squeeze_dims,
                                         const framework::DDim &in_dims) {
-    int num_squeeze_dims = static_cast<int>(squeeze_dims.size());
+    size_t num_squeeze_dims = squeeze_dims.size();
     int cnt_squeezed_dims = 0;
     bool should_squeeze[9] = {false};
 
     // Determines number of dimensions of output tensor after squeeze.
     // Mark and count the dimensions need to be squeezed
     if (num_squeeze_dims == 0) {
-      for (int idx = 0; idx < static_cast<int>(in_dims.size()); ++idx) {
+      for (int idx = 0; idx < in_dims.size(); ++idx) {
         if (in_dims[idx] == 1) {
           should_squeeze[idx] = true;
           ++cnt_squeezed_dims;
         }
       }
     } else {
-      for (int idx = 0; idx < num_squeeze_dims; ++idx) {
+      for (size_t idx = 0; idx < num_squeeze_dims; ++idx) {
         int current = squeeze_dims[idx] < 0 ? squeeze_dims[idx] + in_dims.size()
                                             : squeeze_dims[idx];
-        // Check current index.
+        // Check current index, the upper limit has beed checked in line 36.
         PADDLE_ENFORCE(current >= 0,
-                       "Invalid axis, negative axis is out of range.");
-        // PADDLE_ENFORCE_LT(current, in_dims.size(), "Invalid axis is given.");
-        PADDLE_ENFORCE(
-            in_dims[current] == 1,
-            "Invalid axis index, the axis will be squeezed should be 1.");
+                       "Invalid axis, the negative axis is out of range.");
+        PADDLE_ENFORCE(in_dims[current] == 1,
+                       "Invalid axis index, the axis that will be squeezed "
+                       "should equal 1.");
 
         if (!(should_squeeze[current])) {
           ++cnt_squeezed_dims;
@@ -84,8 +84,7 @@ class SqueezeOpInferShape : public framework::InferShapeBase {
 
     // Make output dimensions
     std::vector<int64_t> output_shape(in_dims.size() - cnt_squeezed_dims, 0);
-    for (int in_idx = 0, out_idx = 0; in_idx < static_cast<int>(in_dims.size());
-         ++in_idx) {
+    for (int in_idx = 0, out_idx = 0; in_idx < in_dims.size(); ++in_idx) {
       if (!should_squeeze[in_idx]) {
         output_shape[out_idx++] = in_dims[in_idx];
       }
@@ -123,7 +122,7 @@ class SqueezeOpMaker : public framework::OpProtoAndCheckerMaker {
     AddInput("X", "(Tensor). The input tensor of squeeze operator.");
     AddOutput("Out", "(Tensor). The output tensor of squeeze operator.");
     AddAttr<std::vector<int>>("axes",
-                              "(std::vector<int>). List of positive integers,"
+                              "(std::vector<int>). List of integers,"
                               " indicate the dimensions to squeeze.")
         .SetDefault({});
     AddAttr<bool>("inplace",