[extract method] prepare analyzer to be reused, simplify error handling

GitOrigin-RevId: 26054522329a8a1a4d84997fb39b957707de9737

java/java-impl-refactorings/src/com/intellij/refactoring/extractMethod/newImpl/CodeFragmentAnalyzer.kt

@@ -269,5 +269,14 @@ class CodeFragmentAnalyzer(val elements: List<PsiElement>) {
       val artificialExpression = requireNotNull(artificialReturn.returnValue)
       return inferNullability(listOf(artificialExpression))
     }
+
+    fun createAnalyzer(elements: List<PsiElement>): CodeFragmentAnalyzer? {
+      return try {
+        CodeFragmentAnalyzer(elements)
+      }
+      catch (e: ExtractException) {
+        null
+      }
+    }
   }
 }

java/java-impl-refactorings/src/com/intellij/refactoring/extractMethod/newImpl/MethodExtractor.kt

@@ -60,24 +60,27 @@ class MethodExtractor {
       return
     }
 
-    val elements = ExtractSelector().suggestElementsToExtract(file, range)
-    if (elements.isEmpty()) {
-      showExtractErrorHint(editor, RefactoringBundle.message("selected.block.should.represent.a.set.of.statements.or.an.expression"))
-      return
-    }
-
-    try {
-      val analyzer = CodeFragmentAnalyzer(elements)
-      val outputVariables = analyzer.findOutputVariables().sortedBy { variable -> variable.textRange.startOffset }
-      if (outputVariables.size > 1) {
-        ResultObjectExtractor.run(editor, outputVariables, elements)
-        return
-      }
-    } catch (_: ExtractException) {
-    }
-
     coroutineScope.launch {
       withContext(Dispatchers.EDT) { //TODO minimize edt context
+
+        val elements = ExtractSelector().suggestElementsToExtract(file, range)
+        if (elements.isEmpty()) {
+          showExtractErrorHint(editor, RefactoringBundle.message("selected.block.should.represent.a.set.of.statements.or.an.expression"))
+          return@withContext
+        }
+
+        val analyzer = CodeFragmentAnalyzer.createAnalyzer(elements)
+        if (analyzer == null) {
+          showExtractErrorHint(editor, JavaRefactoringBundle.message("extract.method.control.flow.analysis.failed"))
+          return@withContext
+        }
+
+        val outputVariables = analyzer.findOutputVariables().sortedBy { variable -> variable.textRange.startOffset }
+        if (outputVariables.size > 1) {
+          ResultObjectExtractor.run(editor, outputVariables, elements)
+          return@withContext
+        }
+
         val prepareStart = System.currentTimeMillis()
         val descriptorsForAllTargetPlaces = prepareDescriptorsForAllTargetPlaces(file.project, editor, elements)
         if (descriptorsForAllTargetPlaces.isEmpty()) return@withContext