Fix a lot of C++ build warnings (#16411)

Summary:
I went through my build log and did what I thought were reasonable fixes to all the C++ compilation warnings that came up
Pull Request resolved: https://github.com/pytorch/pytorch/pull/16411

Differential Revision: D13901006

Pulled By: jamesr66a

fbshipit-source-id: 02df4e3e5a5c8dd9e69ac9f065cd3f2a80645033

4 files changed, 8 insertions, 9 deletions

diff --git a/aten/src/ATen/SparseTensorImpl.h b/aten/src/ATen/SparseTensorImpl.h
index 84ca155b3c..7afc03d31f 100644
--- a/aten/src/ATen/SparseTensorImpl.h
+++ b/aten/src/ATen/SparseTensorImpl.h
@@ -88,7 +88,7 @@ public:
   // (this could make some of the stored indices out-of-bound and thus unsafe).
   void resize_(int64_t sparse_dim, int64_t dense_dim, IntList size) {
     AT_CHECK(allow_tensor_metadata_change(), "resize_ is not allowed on Tensor created from .data or .detach()");
-    AT_CHECK(sparse_dim + dense_dim == size.size(), "number of dimensions must be sparse_dim (", sparse_dim, ") + dense_dim (", dense_dim, "), but got ", size.size());
+    AT_CHECK(sparse_dim + dense_dim == static_cast<int64_t>(size.size()), "number of dimensions must be sparse_dim (", sparse_dim, ") + dense_dim (", dense_dim, "), but got ", size.size());
     if (nnz() > 0) {
       auto alt_options_msg = "You could try the following options:\n\
 1. If you need an empty sparse tensor of this size, call `x = torch.sparse_coo_tensor(size)`.\n\
@@ -146,7 +146,7 @@ public:
   // NOTE: this function will resize the sparse tensor and also set `indices` and `values` to empty.
   void resize_and_clear_(int64_t sparse_dim, int64_t dense_dim, IntList size) {
     AT_CHECK(allow_tensor_metadata_change(), "resize_and_clear_ is not allowed on Tensor created from .data or .detach()");
-    AT_CHECK(sparse_dim + dense_dim == size.size(), "number of dimensions must be sparse_dim (", sparse_dim, ") + dense_dim (", dense_dim, "), but got ", size.size());
+    AT_CHECK(sparse_dim + dense_dim == static_cast<int64_t>(size.size()), "number of dimensions must be sparse_dim (", sparse_dim, ") + dense_dim (", dense_dim, "), but got ", size.size());
 
     sizes_ = size.vec();
     sparse_dim_ = sparse_dim;
diff --git a/aten/src/ATen/core/jit_type.h b/aten/src/ATen/core/jit_type.h
index 54b1d02126..bca3f3b46e 100644
--- a/aten/src/ATen/core/jit_type.h
+++ b/aten/src/ATen/core/jit_type.h
@@ -309,7 +309,7 @@ struct CAFFE2_API TensorType : public DynamicType {
 
   at::ScalarType scalarType() const { return scalar_type_; }
   at::Device device() const { return device_; }
-  int dim() const { return dim_; }
+  int64_t dim() const { return dim_; }
   bool requires_grad() const override { return requires_grad_; }
 
   TensorTypePtr toScalarType(at::ScalarType type){
@@ -317,7 +317,7 @@ struct CAFFE2_API TensorType : public DynamicType {
     t->scalar_type_ = type;
     return t;
   }
-  TensorTypePtr withDim(int new_dim) {
+  TensorTypePtr withDim(size_t new_dim) {
     auto t = TensorType::create(*this);
     t->dim_ = new_dim;
     return t;
@@ -360,7 +360,7 @@ protected:
                  tensor.dim(),
                  tensor.is_variable() && tensor.requires_grad(),
                  kind) {}
-  TensorType(at::ScalarType scalar_type, at::Device device, int dim, bool requires_grad=true, TypeKind kind=TypeKind::TensorType)
+  TensorType(at::ScalarType scalar_type, at::Device device, int64_t dim, bool requires_grad=true, TypeKind kind=TypeKind::TensorType)
     : DynamicType(kind)
     , scalar_type_(scalar_type)
     , requires_grad_(at::isFloatingType(scalar_type) && requires_grad)
@@ -370,7 +370,7 @@ protected:
   at::ScalarType scalar_type_;
   bool requires_grad_;
   at::Device device_;
-  int dim_;
+  int64_t dim_;
 };
 
 struct CompleteTensorType;
diff --git a/aten/src/ATen/core/stack.h b/aten/src/ATen/core/stack.h
index 42d1b58bd2..32c07a4d53 100644
--- a/aten/src/ATen/core/stack.h
+++ b/aten/src/ATen/core/stack.h
@@ -67,7 +67,7 @@ static inline void pop(Stack& stack, Types&... args) {
 }
 template <typename... Types>
 static inline void push(Stack& stack, Types&&... args) {
-  std::initializer_list<int>{(stack.emplace_back(std::forward<Types>(args)), 0)...};
+  (void)std::initializer_list<int>{(stack.emplace_back(std::forward<Types>(args)), 0)...};
 }
 
 // The packer here is carefully written not to make any unnecessary
diff --git a/aten/src/ATen/test/basic.cpp b/aten/src/ATen/test/basic.cpp
index 7d301b4dba..83a2340dd4 100644
--- a/aten/src/ATen/test/basic.cpp
+++ b/aten/src/ATen/test/basic.cpp
@@ -207,8 +207,7 @@ void TestTensorFromTH() {
   int a = 4;
   THFloatTensor* t = THFloatTensor_newWithSize2d(a, a);
   THFloatTensor_fill(t, a);
-  Tensor tt = CPU(kFloat).unsafeTensorFromTH(t, false);
-  ASSERT_NO_THROW(tt);
+  ASSERT_NO_THROW(CPU(kFloat).unsafeTensorFromTH(t, false));
 }
 
 void TestToCFloat() {