Optimize logic

Author: 5265325

build.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 
-VERSION="1.14"
+VERSION="1.15"
 
 help() {
     echo "Version v"$VERSION
@@ -88,7 +88,9 @@ build_diff_proj() {
     # create soft link ($BUILD_PATH/*.v -> $PROJECT_PATH/$VSRC_FOLDER/*.v)
     create_soft_link $BUILD_PATH $PROJECT_PATH/$VSRC_FOLDER \"*.v\"
     # create soft link ($PROJECT_PATH/difftest -> $LIBRARIES_HOME/difftest)
-    eval "ln -s \"`realpath --relative-to="$PROJECT_PATH" "$LIBRARIES_HOME"`/$DIFFTEST_FOLDER\" \"$PROJECT_PATH/$DIFFTEST_FOLDER\" 1>/dev/null 2>&1"
+    if [[ ! -L $PROJECT_PATH/$DIFFTEST_FOLDER ]]; then
+        eval "ln -s \"`realpath --relative-to="$PROJECT_PATH" "$LIBRARIES_HOME"`/$DIFFTEST_FOLDER\" \"$PROJECT_PATH/$DIFFTEST_FOLDER\" 1>/dev/null 2>&1"
+    fi
 
     compile_dramsim3
     compile_nemu