Refactor attribute detection (#3493)

Refactor attribute detection

Author: taketwo

common/include/pcl/pcl_macros.h

@@ -365,22 +365,22 @@ aligned_free (void* ptr)
  *
  * \ingroup common
  */
-#if __has_cpp_attribute(fallthrough) && !(defined(__clang__) && __cplusplus < 201703L)
+#if (__cplusplus >= 201703L) || (defined(_MSC_VER) && (_MSC_VER >= 1910) && (_MSVC_LANG >= 201703L))
   #define PCL_FALLTHROUGH [[fallthrough]];
 #elif defined(__clang__)
   #define PCL_FALLTHROUGH [[clang::fallthrough]];
-#elif defined(__GNUC__)
-  #if __GNUC__ >= 7
-    #define PCL_FALLTHROUGH [[gnu::fallthrough]];
-  #else
-    #define PCL_FALLTHROUGH ;
-  #endif
+#elif defined(__GNUC__) && (__GNUC__ >= 7)
+  #define PCL_FALLTHROUGH [[gnu::fallthrough]];
 #else
-  #define PCL_FALLTHROUGH ;
+  #define PCL_FALLTHROUGH
 #endif
 
-#if __has_cpp_attribute(nodiscard)
+#if (__cplusplus >= 201703L) || (defined(_MSC_VER) && (_MSC_VER >= 1911) && (_MSVC_LANG >= 201703L))
   #define PCL_NODISCARD [[nodiscard]]
+#elif defined(__clang__) && (PCL_LINEAR_VERSION(__clang_major__, __clang_minor__, 0) >= PCL_LINEAR_VERSION(3, 9, 0))
+  #define PCL_NODISCARD [[clang::warn_unused_result]]
+#elif defined(__GNUC__)
+  #define PCL_NODISCARD [[gnu::warn_unused_result]]
 #else
   #define PCL_NODISCARD
 #endif

common/src/PCLPointCloud2.cpp

@@ -63,9 +63,8 @@ pcl::PCLPointCloud2::concatenate (pcl::PCLPointCloud2 &cloud1, const pcl::PCLPoi
   {
     case 1:
       cloud1 = cloud2;
-      PCL_FALLTHROUGH;
+      PCL_FALLTHROUGH
     case 0:
-      PCL_FALLTHROUGH;
     case 2:
       cloud1.header.stamp = std::max (cloud1.header.stamp, cloud2.header.stamp);
       return (true);

common/src/pcl_base.cpp

@@ -76,14 +76,14 @@ pcl::PCLBase<pcl::PCLPointCloud2>::setInputCloud (const PCLPointCloud2ConstPtr &
   {
     switch (datatype)
     {
-      case pcl::PCLPointField::INT8: PCL_FALLTHROUGH;
+      case pcl::PCLPointField::INT8:
       case pcl::PCLPointField::UINT8: return 1;
 
-      case pcl::PCLPointField::INT16: PCL_FALLTHROUGH;
+      case pcl::PCLPointField::INT16:
       case pcl::PCLPointField::UINT16: return 2;
 
-      case pcl::PCLPointField::INT32: PCL_FALLTHROUGH;
-      case pcl::PCLPointField::UINT32: PCL_FALLTHROUGH;
+      case pcl::PCLPointField::INT32:
+      case pcl::PCLPointField::UINT32:
       case pcl::PCLPointField::FLOAT32: return 4;
 
       case pcl::PCLPointField::FLOAT64: return 8;