build scripts: added option to clear incremental caches to recover after failing compilation

build/scripts/common_tests.gant

@@ -27,7 +27,8 @@ target(compile: "Compile project") {
   }
 
   loadProject()
-  projectBuilder.targetFolder = projectBuilder.buildIncrementally ? "$home/out/incremental-build" : out
+  prepareOutputFolder()
+
   if (!isDefined("avoid.project.rebuild")) {
     projectBuilder.cleanOutput()
     projectBuilder.buildAll()

build/scripts/utils.gant

@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+
+import com.intellij.openapi.util.io.FileUtil
 import org.jetbrains.jps.gant.JpsGantTool
 import org.jetbrains.jps.gant.TeamCityBuildInfoPrinter
 import org.jetbrains.jps.model.java.JavaSourceRootType
@@ -146,6 +148,14 @@ binding.setVariable("loadProject", {
   compilerOptions.ADDITIONAL_OPTIONS_STRING = compilerOptions.ADDITIONAL_OPTIONS_STRING.replace("-Xlint:unchecked", "")
 })
 
+binding.setVariable("prepareOutputFolder", {
+  projectBuilder.targetFolder = projectBuilder.buildIncrementally ? "$home/out/incremental-build" : out
+  if (projectBuilder.buildIncrementally && Boolean.parseBoolean(p("jps.build.clear.incremental.caches", "false"))) {
+    FileUtil.delete(new File(projectBuilder.targetFolder))
+    FileUtil.delete(new File(projectBuilder.dataStorageRoot))
+  }
+})
+
 boolean hasSourceRoots(JpsModule module) {
   return module.getSourceRoots(JavaSourceRootType.SOURCE).iterator().hasNext()
 }