Debugger: allow to evaluate kotlin expressions in java files

#KT-7549 Fixed

 If the context is inside PsiJavaFile, get list of all local variables available in current frame (this logic was removed in 29778311e8 01.12.2015 Drop unnecesary logic about additional context for lambda in debugger). For each variable create KtProperty inside top-level KtFunction in KtFile and set it as contextElement for KtCodeFragment. This file should have all imports from PsiJavaFile. We do not create properties on top-level because they will be highlighted as top-level vals/vars.

compiler/frontend/src/org/jetbrains/kotlin/psi/KtCodeFragment.kt

@@ -16,6 +16,7 @@
 
 package org.jetbrains.kotlin.psi
 
+import com.intellij.openapi.diagnostic.Logger
 import com.intellij.openapi.project.Project
 import com.intellij.openapi.util.Key
 import com.intellij.psi.*
@@ -25,6 +26,7 @@ import com.intellij.psi.search.GlobalSearchScope
 import com.intellij.psi.tree.IElementType
 import com.intellij.testFramework.LightVirtualFile
 import org.jetbrains.kotlin.idea.KotlinFileType
+import org.jetbrains.kotlin.psi.psiUtil.getElementTextWithContext
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.utils.addToStdlib.check
 import java.util.*
@@ -41,6 +43,10 @@ abstract class KtCodeFragment(
     private var viewProvider = super.getViewProvider() as SingleRootFileViewProvider
     private var imports = LinkedHashSet<String>()
 
+    private val fakeContextForJavaFile: PsiElement? by lazy {
+        this.getCopyableUserData(FAKE_CONTEXT_FOR_JAVA_FILE)?.invoke()
+    }
+
     init {
         getViewProvider().forceCachedPsi(this)
         init(TokenType.CODE_FRAGMENT, elementType)
@@ -67,7 +73,15 @@ abstract class KtCodeFragment(
 
     override fun isValid() = true
 
-    override fun getContext() = context
+    override fun getContext(): PsiElement? {
+        if (fakeContextForJavaFile != null) return fakeContextForJavaFile
+        if (context !is KtElement) {
+            LOG.warn("CodeFragment with non-kotlin context should have fakeContextForJavaFile set: \noriginalContext = ${context?.getElementTextWithContext()}")
+            return null
+        }
+
+        return context
+    }
 
     override fun getResolveScope() = context?.resolveScope ?: super.getResolveScope()
 
@@ -171,6 +185,8 @@ abstract class KtCodeFragment(
     companion object {
         val IMPORT_SEPARATOR: String = ","
         val RUNTIME_TYPE_EVALUATOR: Key<Function1<KtExpression, KotlinType?>> = Key.create("RUNTIME_TYPE_EVALUATOR")
-        val ADDITIONAL_CONTEXT_FOR_LAMBDA: Key<Function0<KtElement?>> = Key.create("ADDITIONAL_CONTEXT_FOR_LAMBDA")
+        val FAKE_CONTEXT_FOR_JAVA_FILE: Key<Function0<KtElement>> = Key.create("FAKE_CONTEXT_FOR_JAVA_FILE")
+
+        private val LOG = Logger.getInstance(KtCodeFragment::class.java)
     }
 }