Fix AppleClang warnings (LBANN#2453)

* Make the debug flag handling in CMake more robust

* Fix clang warnings

CMakeLists.txt

@@ -819,20 +819,33 @@ endif (LBANN_HAS_CUDA)
 
 # Fix the -g issue with Clang on OSX
 if (APPLE)
+  message("** CMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS}")
+  message("** CMAKE_CXX_FLAGS_DEBUG=${CMAKE_CXX_FLAGS_DEBUG}")
+
   # Remove -g from the options
-  string(REPLACE  "-g" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
-  string(REPLACE  "-g" "" CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG}")
+  string(REGEX REPLACE
+    " ?-g[gdb0-9]*"
+    ""
+    CMAKE_CXX_FLAGS
+    "${CMAKE_CXX_FLAGS}")
+  string(REGEX REPLACE
+    " ?-g[gdb0-9]*"
+    ""
+    CMAKE_CXX_FLAGS_DEBUG
+    "${CMAKE_CXX_FLAGS_DEBUG}")
 
   # Get all the sources and add "-g" to all of them.
   get_target_property(_LBANN_SRCS lbann SOURCES)
-  set_source_files_properties(${_LBANN_SRCS}
-    PROPERTIES COMPILE_OPTIONS "-g")
 
   # Cleanup source files
   foreach (bad_file IN LISTS _LBANN_SRCS)
     get_source_file_property(
       _SRC_COMPILE_OPTS "${bad_file}" COMPILE_OPTIONS)
-    string(REPLACE "-g" "" _SRC_COMPILE_OPTS "${COMPILE_OPTIONS}")
+    string(REGEX REPLACE
+      " ?-g[gdb0-9]*"
+      ""
+      _SRC_COMPILE_OPTS
+      "${COMPILE_OPTIONS}")
     set_source_files_properties(
       "${bad_file}" PROPERTIES COMPILE_OPTIONS "${_SRC_COMPILE_OPTS}")
   endforeach ()

include/lbann/data_ingestion/readers/sample_list_open_files_impl.hpp

@@ -642,7 +642,7 @@ inline void sample_list_open_files<sample_name_t, file_handle_t>::reorder()
 {
   // Interleaving was done over files (all samples in a file are consecutive
   if (this->m_stride > 1ul) { // undo interleaving
-    samples_t tmp_sample_list[this->m_stride];
+    std::vector<samples_t> tmp_sample_list(this->m_stride);
     sample_file_id_t last_index = 0;
     size_t interleave_idx = 0;
     for (const auto& s : this->m_sample_list) {

src/data_ingestion/readers/data_reader_mesh.cpp

@@ -140,9 +140,9 @@ std::string mesh_reader::construct_filename(std::string channel,
                                             uint64_t data_id)
 {
   std::string filename = get_file_dir() + channel + m_suffix + "/" + channel;
-  char idx[m_index_length + 1];
-  std::snprintf(idx, m_index_length + 1, m_index_format_str.c_str(), data_id);
-  return filename + std::string(idx) + ".bin";
+  std::vector<char> idx(m_index_length + 1, '\0');
+  std::snprintf(idx.data(), m_index_length + 1, m_index_format_str.c_str(), data_id);
+  return filename + std::string(idx.data()) + ".bin";
 }
 
 void mesh_reader::horizontal_flip(CPUMat& mat)

src/layers/image/bilinear_resize.cpp

@@ -67,11 +67,11 @@ void bilinear_resize_layer<TensorDataType, Layout, Device>::fp_compute()
 
           // Find input pixels near interpolation point
           const auto input_col = static_cast<El::Int>(std::floor(x - half));
-          const auto& input_col0 = std::max(input_col, El::Int(0));
-          const auto& input_col1 = std::min(input_col + 1, input_width - 1);
+          const auto input_col0 = std::max(input_col, El::Int(0));
+          const auto input_col1 = std::min(input_col + 1, input_width - 1);
           const auto input_row = static_cast<El::Int>(std::floor(y - half));
-          const auto& input_row0 = std::max(input_row, El::Int(0));
-          const auto& input_row1 = std::min(input_row + 1, input_height - 1);
+          const auto input_row0 = std::max(input_row, El::Int(0));
+          const auto input_row1 = std::min(input_row + 1, input_height - 1);
 
           // Interpolation point relative to input pixel centers
           const auto& unit_x = x - (input_col + half);