[flang] Separate temporary and user-specified object files

[awarzynski]

Summary

This patch updates the flang bash scripts to differentiate between
object files provided by the user and intermediate object files
generated by the script. The latter are an "implementation detail" that
should not be visible to the end user (i.e. deleted before the scripts
exits). The former should be preserved.

Fixes https://github.com/flang-compiler/f18-llvm-project/issues/1348

[sscalpone]

Tested and executed. Works for me!

flang/tools/f18/flang

 #   * library files (to be linked into the final executable)
 #
 # INPUTS:
 #   $1 - all input files to be categorised (array, name reference)
 # OUTPUTS:
 #   $2 - Fortran source files extracted from $1 (array, name reference)
 #   $3 - other source files extracted from $1 (array, name reference)
 #   $4 - object files extracted from $1 (array, name reference)
-#   $4 - lib files extracted from $1 (array, name reference)
+#   $5 - lib files extracted from $1 (array, name reference)
 # =============================================================================
 categorise_files()
 {
   local -n -r all_files=$1
   local -n fortran_sources=$2
   local -n other_sources=$3
-  local -n libs=$4
+  local -n objects=$4
+  local -n libs=$5
 
   for current_file in "${all_files[@]}"; do
     file_ext=${current_file##*.}
     if [[ $file_ext == "f" ]] || [[ $file_ext == "f90" ]] ||
        [[ $file_ext == "f" ]] || [[ $file_ext == "F" ]] || [[ $file_ext == "ff" ]] ||
        [[ $file_ext == "f90" ]] || [[ $file_ext == "F90" ]] || [[ $file_ext == "ff90" ]] ||
        [[ $file_ext == "f95" ]] || [[ $file_ext == "F95" ]] || [[ $file_ext == "ff95" ]] ||
        [[ $file_ext == "cuf" ]] || [[ $file_ext == "CUF" ]] || [[ $file_ext == "f18" ]] ||
        [[ $file_ext == "F18" ]] || [[ $file_ext == "ff18" ]]; then
       fortran_sources+=($current_file)
     elif [[ $file_ext == "a" ]] || [[ $file_ext == "so" ]]; then
       libs+=($current_file)
     elif [[ $file_ext == "o" ]]; then
-      object_files+=($current_file)
+      objects+=($current_file)
     else
       other_sources+=($current_file)
     fi
   done
 }
 
 # === categorise_opts ==========================================================
 #

 main() {
   parse_args "$@"
 
   if [[ $PRINT_VERSION == "True" ]]; then
     echo "flang version @FLANG_VERSION@"
     exit 0
   fi
 
+  # Source, object and library files provided by the user
   local fortran_source_files=()
   local other_source_files=()
   local object_files=()
   local lib_files=()
   categorise_files INPUT_FILES fortran_source_files other_source_files object_files lib_files
 
   if [[ $PREPROCESS_ONLY == "True" ]]; then
     preprocess fortran_source_files other_source_files OPTIONS
for idx in "${!fortran_source_files[@]}"; do
     if [[ $ret_status != 0 ]]; then
          echo flang: in "$PWD", flang-new failed with exit status "$ret_status": "$wd/bin/flang-new" "${flang_options[@]}" "$@" >&2
          exit "$ret_status"
     fi
   done
 
   # STEP 2: Compile Fortran Source Files
   readonly ext_fc="${F18_FC:-gfortran}"
+  # Temporary object files generated by this script. To be deleted at the end.
+  local temp_object_files=()
   for idx in "${!fortran_source_files[@]}"; do
     # We always have to specify the output name with `-o <out_obj_file>`. This
     # is because we are using the unparsed rather than the original source file
     # below. As a result, we cannot rely on the compiler-generated output name.
     out_obj_file=$(get_relocatable_name "${fortran_source_files[$idx]}")
 
     set +e
     $ext_fc "-c" "${ext_fc_options[@]}" "${unparsed_file_base}_${idx}.f90" "-o" "${out_obj_file}"
     ret_status=$?
     set -e
     if [[ $ret_status != 0 ]]; then
       echo flang: in "$PWD", "$ext_fc" failed with exit status "$ret_status": "$ext_fc" "${ext_fc_options[@]}" "$@" >&2
          exit "$ret_status"
     fi
-    object_files+=(${out_obj_file})
+    temp_object_files+=(${out_obj_file})
   done
 
   # Delete the unparsed files
   for idx in "${!fortran_source_files[@]}"; do
     rm "${unparsed_file_base}_${idx}.f90"
   done
 
   # STEP 3: Compile Other Source Files
   for idx in "${!other_source_files[@]}"; do
     # We always specify the output name with `-o <out_obj_file>`. The user
     # might have used `-o`, but we never add it to $OPTIONS (or
     # $ext_fc_options). Hence we need to use `get_relocatable_name`.
     out_obj_file=$(get_relocatable_name "${other_source_files[$idx]}")
 
     set +e
     $ext_fc "-c" "${ext_fc_options[@]}" "${other_source_files[${idx}]}" "-o" "${out_obj_file}"
     ret_status=$?
     set -e
     if [[ $ret_status != 0 ]]; then
       echo flang: in "$PWD", "$ext_fc" failed with exit status "$ret_status": "$ext_fc" "${ext_fc_options[@]}" "$@" >&2
          exit "$ret_status"
     fi
-    object_files+=(${out_obj_file})
+    temp_object_files+=(${out_obj_file})
   done
 
   # STEP 4: Link
   if [[ $COMPILE_ONLY == "True" ]]; then
     exit 0;
   fi
 
-  if [[ ${#object_files[@]} -ge 1 ]]; then
+  if [[ ${#temp_object_files[@]} -ge 1 ]] || [[ ${#object_files[@]} -ge 1 ]] ; then
     # If $OUTPUT_FILE was specified, use it for the output name.
     if [[ ! -z ${OUTPUT_FILE:+x} ]]; then
       output_definition="-o $OUTPUT_FILE"
     else
       output_definition=""
     fi
 
     set +e
-    $ext_fc "${ext_fc_options[@]}" "${object_files[@]}" "${lib_files[@]}" ${output_definition:+$output_definition}
+    $ext_fc "${ext_fc_options[@]}" "${object_files[@]}" "${temp_object_files[@]}" "${lib_files[@]}" ${output_definition:+$output_definition}
     ret_status=$?
     set -e
     if [[ $ret_status != 0 ]]; then
          echo flang: in "$PWD", "$ext_fc" failed with exit status "$ret_status": "$ext_fc" "${ext_fc_options[@]}" "$@" >&2
          exit "$ret_status"
     fi
   fi
 
   # Delete intermediate object files
   for idx in "${!fortran_source_files[@]}"; do
-    rm "${object_files[$idx]}"
+    rm "${temp_object_files[$idx]}"
   done
 }
 
 main "${@}"