Move building of artifacts to separate subdirectory.

This avoids potential issues with clashing translation unit name in case
pre-existing translation units exist in the archiving directory.

Author: NlightNFotis

src/libcprover-cpp/add_dependencies.sh

@@ -19,6 +19,14 @@ LIB_LIST=$@
 # unit name collisions which affect linking against the final artefact. For more
 # details, please look at https://github.com/diffblue/cbmc/issues/7586 .
 
+# Create a temporary folder for this script to work in.
+rm -rf add_dependencies_tmp
+mkdir add_dependencies_tmp
+cd add_dependencies_tmp
+
+# The full path of the current "root" directory
+WORKING_DIR=$(pwd)
+
 # For each library to add:
 for lib in ${LIB_LIST}; do
   # We will unpack and rename all .o of dependent libraries marking them with
@@ -33,18 +41,18 @@ for lib in ${LIB_LIST}; do
   # Unpack the library
   ${AR_COMMAND} -x ${lib}
 
-  # Rename all object file in the library prepending "${LIBNAME}_" to avoid
-  # clashes.
+  # Rename all object files in the library prepending "${LIBNAME}_" to avoid
+  # clashes, and move to the "root" folder.
   for obj in *.o; do
-    mv ${obj} "${LIBNAME}_${obj}"
+    mv ${obj} "${WORKING_DIR}/${LIBNAME}_${obj}"
   done
 
   # Move back to the working directory.
-  cd ..
+  cd "${WORKING_DIR}"
 done
 
 # Append all the unpacked files to the destination library
-${AR_COMMAND} -rcs ${DESTINATION} **/*.o
+${AR_COMMAND} -rcs ${DESTINATION} *.o
 
 # TODO: See if we need to do some cleanup in order to save cache space for
 # Github actions runners.