Added translationUnitForInference

Author: oxisto

cpg-core/src/main/kotlin/de/fraunhofer/aisec/cpg/ScopeManager.kt

@@ -868,6 +868,27 @@ class ScopeManager : ScopeProvider {
 
         return symbols.singleOrNull()
     }
+
+    /**
+     * Returns the [TranslationUnitDeclaration] that should be used for inference, especially for
+     * global declarations.
+     *
+     * @param TypeToInfer the type of the node that should be inferred
+     * @param source the source that was responsible for the inference
+     */
+    fun <TypeToInfer : Node> translationUnitForInference(
+        source: Node
+    ): TranslationUnitDeclaration? {
+        // TODO(oxisto): This workaround is needed because it seems that not all types have a proper
+        //  context :(. In this case we need to fall back to the global scope's astNode, which can
+        // be
+        //  error-prone in a multi-language scenario.
+        return if (source.ctx == null) {
+            globalScope?.astNode as? TranslationUnitDeclaration
+        } else {
+            source.language.translationUnitForInference<TypeToInfer>(source)
+        }
+    }
 }
 
 /**

cpg-core/src/main/kotlin/de/fraunhofer/aisec/cpg/frontends/Language.kt

@@ -30,20 +30,28 @@ import com.fasterxml.jackson.core.JsonGenerator
 import com.fasterxml.jackson.databind.JsonSerializer
 import com.fasterxml.jackson.databind.SerializerProvider
 import com.fasterxml.jackson.databind.annotation.JsonSerialize
-import de.fraunhofer.aisec.cpg.*
+import de.fraunhofer.aisec.cpg.CallResolutionResult
+import de.fraunhofer.aisec.cpg.SignatureResult
+import de.fraunhofer.aisec.cpg.TranslationContext
+import de.fraunhofer.aisec.cpg.ancestors
 import de.fraunhofer.aisec.cpg.graph.Name
 import de.fraunhofer.aisec.cpg.graph.Node
 import de.fraunhofer.aisec.cpg.graph.OverlayNode
 import de.fraunhofer.aisec.cpg.graph.declarations.Declaration
 import de.fraunhofer.aisec.cpg.graph.declarations.FunctionDeclaration
+import de.fraunhofer.aisec.cpg.graph.declarations.NamespaceDeclaration
+import de.fraunhofer.aisec.cpg.graph.declarations.TranslationUnitDeclaration
 import de.fraunhofer.aisec.cpg.graph.edges.ast.TemplateArguments
+import de.fraunhofer.aisec.cpg.graph.scopes.GlobalScope
+import de.fraunhofer.aisec.cpg.graph.scopes.Scope
 import de.fraunhofer.aisec.cpg.graph.statements.expressions.BinaryOperator
 import de.fraunhofer.aisec.cpg.graph.statements.expressions.CallExpression
 import de.fraunhofer.aisec.cpg.graph.statements.expressions.Reference
 import de.fraunhofer.aisec.cpg.graph.types.*
 import de.fraunhofer.aisec.cpg.graph.unknownType
 import de.fraunhofer.aisec.cpg.helpers.Util
 import de.fraunhofer.aisec.cpg.passes.SymbolResolver
+import de.fraunhofer.aisec.cpg.passes.inference.Inference
 import java.io.File
 import kotlin.reflect.KClass
 import kotlin.reflect.full.primaryConstructor
@@ -388,6 +396,35 @@ abstract class Language<T : LanguageFrontend<*, *>> : Node() {
             ref.candidates.singleOrNull()
         }
     }
+
+    /**
+     * There are some cases where our [Inference] system needs to place declarations, e.g., a
+     * [NamespaceDeclaration] in the [GlobalScope]. The issue with that is that the [Scope.astNode]
+     * of the global scope is always the last parsed [TranslationUnitDeclaration] and we might end
+     * up adding the declaration to some random translation unit, where it does not really belong.
+     *
+     * Therefore, we give the language a chance to return a [TranslationUnitDeclaration] where the
+     * declaration should be placed. If the language does not override this function, the default
+     * implementation will return the first [TranslationUnitDeclaration] in
+     * [TranslationContext.currentComponent].
+     *
+     * But languages might choose to take the information of [TypeToInfer] and [source] and create a
+     * specific [TranslationUnitDeclaration], e.g., for each namespace that is inferred globally or
+     * try to put all inferred declarations into one specific (inferred) new translation unit.
+     *
+     * @param TypeToInfer the type of the node that should be inferred
+     * @param source the source that was responsible for the inference
+     */
+    fun <TypeToInfer : Node> translationUnitForInference(source: Node): TranslationUnitDeclaration {
+        val tu = source.ctx?.currentComponent?.translationUnits?.firstOrNull()
+        if (tu == null) {
+            throw TranslationException(
+                "No translation unit found that should be used for inference"
+            )
+        }
+
+        return tu
+    }
 }
 
 /**

cpg-core/src/main/kotlin/de/fraunhofer/aisec/cpg/passes/TypeResolver.kt

@@ -49,6 +49,7 @@ open class TypeResolver(ctx: TranslationContext) : ComponentPass(ctx) {
     lateinit var walker: SubgraphWalker.ScopedWalker
 
     override fun accept(component: Component) {
+        ctx.currentComponent = component
         resolveFirstOrderTypes()
         refreshNames()
 

cpg-core/src/main/kotlin/de/fraunhofer/aisec/cpg/passes/inference/PassHelper.kt

@@ -83,7 +83,7 @@ fun Pass<*>.tryNamespaceInference(name: Name, source: Node): NamespaceDeclaratio
         holder = tryScopeInference(parentName, source)
     }
 
-    return (holder ?: source.translationUnit ?: scopeManager.globalScope?.astNode)
+    return (holder ?: scopeManager.translationUnitForInference<NamespaceDeclaration>(source))
         ?.startInference(ctx)
         ?.inferNamespaceDeclaration(name, null, source)
 }
@@ -133,7 +133,7 @@ internal fun Pass<*>.tryRecordInference(type: Type, source: Node): RecordDeclara
     }
 
     val record =
-        (holder ?: source.translationUnit ?: scopeManager.globalScope?.astNode)
+        (holder ?: scopeManager.translationUnitForInference<RecordDeclaration>(source))
             ?.startInference(ctx)
             ?.inferRecordDeclaration(type, kind, source)
 
@@ -197,7 +197,10 @@ internal fun Pass<*>.tryVariableInference(ref: Reference): VariableDeclaration?
     } else if (ref.language is HasGlobalVariables) {
         // We can try to infer a possible global variable (at top-level), if the language
         // supports this
-        scopeManager.globalScope?.astNode?.startInference(this.ctx)?.inferVariableDeclaration(ref)
+        scopeManager
+            .translationUnitForInference<VariableDeclaration>(ref)
+            ?.startInference(this.ctx)
+            ?.inferVariableDeclaration(ref)
     } else {
         // Nothing to infer
         null