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A simple library to extract a code property graph out of source code. It has support for multiple passes that can extend the analysis after the graph is constructed.
/*
* Copyright (c) 2019, Fraunhofer AISEC. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* $$$$$$\ $$$$$$$\ $$$$$$\
* $$ __$$\ $$ __$$\ $$ __$$\
* $$ / \__|$$ | $$ |$$ / \__|
* $$ | $$$$$$$ |$$ |$$$$\
* $$ | $$ ____/ $$ |\_$$ |
* $$ | $$\ $$ | $$ | $$ |
* \$$$$$ |$$ | \$$$$$ |
* \______/ \__| \______/
*
*/
package de.fraunhofer.aisec.cpg
import de.fraunhofer.aisec.cpg.frontends.HasFirstClassFunctions
import de.fraunhofer.aisec.cpg.frontends.LanguageFrontend
import de.fraunhofer.aisec.cpg.graph.*
import de.fraunhofer.aisec.cpg.graph.declarations.*
import de.fraunhofer.aisec.cpg.graph.scopes.*
import de.fraunhofer.aisec.cpg.graph.statements.*
import de.fraunhofer.aisec.cpg.graph.statements.expressions.Block
import de.fraunhofer.aisec.cpg.graph.statements.expressions.CallExpression
import de.fraunhofer.aisec.cpg.graph.statements.expressions.Reference
import de.fraunhofer.aisec.cpg.graph.statements.expressions.ReferenceTag
import de.fraunhofer.aisec.cpg.graph.types.FunctionPointerType
import de.fraunhofer.aisec.cpg.graph.types.IncompleteType
import de.fraunhofer.aisec.cpg.graph.types.Type
import de.fraunhofer.aisec.cpg.helpers.Util
import de.fraunhofer.aisec.cpg.sarif.PhysicalLocation
import java.util.*
import java.util.function.Predicate
import org.slf4j.LoggerFactory
/**
* The scope manager builds a multi-tree structure of nodes associated to a scope. These scopes
* capture the validity of certain (Variable-, Field-, Record-)declarations but are also used to
* identify outer scopes that should be the target of a jump (continue, break, throw).
*
* Language frontends MUST call [enterScope] and [leaveScope] when they encounter nodes that modify
* the scope and [resetToGlobal] when they first handle a new [TranslationUnitDeclaration].
* Afterwards the currently valid "stack" of scopes within the tree can be accessed.
*
* If a language frontend encounters a [Declaration] node, it MUST call [addDeclaration], rather
* than adding the declaration to the node itself. This ensures that all declarations are properly
* registered in the scope map and can be resolved later.
*/
class ScopeManager : ScopeProvider {
/**
* A map associating each CPG node with its scope. The key type is intentionally a nullable
* [Node] because the [GlobalScope] is not associated to a CPG node when it is first created. It
* is later associated using the [resetToGlobal] function.
*/
private val scopeMap: MutableMap = IdentityHashMap()
/** A lookup map for each scope and its associated FQN. */
private val fqnScopeMap: MutableMap = mutableMapOf()
/** The currently active scope. */
var currentScope: Scope? = null
private set
/** Represents an alias with the name [to] for the particular name [from]. */
data class Alias(var from: Name, var to: Name)
/**
* A cache map of reference tags (computed with [Reference.referenceTag]) and their respective
* pair of original [Reference] and resolved [ValueDeclaration]. This is used by
* [resolveReference] as a caching mechanism.
*/
private val symbolTable = mutableMapOf>()
/**
* In some languages, we can define aliases for names. An example is renaming package imports in
* Go, e.g., to avoid name conflicts.
*
* In reality, they can probably be defined at different scopes for other languages, but for now
* we only allow it for the current file.
*
* This can potentially be used to replace [addTypedef] at some point, which still relies on the
* existence of a [LanguageFrontend].
*/
private val aliases = mutableMapOf>()
/** True, if the scope manager is currently in a [BlockScope]. */
val isInBlock: Boolean
get() = this.firstScopeOrNull { it is BlockScope } != null
/** True, if the scope manager is currently in a [FunctionScope]. */
val isInFunction: Boolean
get() = this.firstScopeOrNull { it is FunctionScope } != null
/** True, if the scope manager is currently in a [RecordScope], e.g. a class. */
val isInRecord: Boolean
get() = this.firstScopeOrNull { it is RecordScope } != null
val globalScope: GlobalScope?
get() = scopeMap[null] as? GlobalScope
/** The current block, according to the scope that is currently active. */
val currentBlock: Block?
get() = this.firstScopeIsInstanceOrNull()?.astNode as? Block
/** The current function, according to the scope that is currently active. */
val currentFunction: FunctionDeclaration?
get() = this.firstScopeIsInstanceOrNull()?.astNode as? FunctionDeclaration
/** The current record, according to the scope that is currently active. */
val currentRecord: RecordDeclaration?
get() = this.firstScopeIsInstanceOrNull()?.astNode as? RecordDeclaration
val currentTypedefs: Collection
get() = this.getCurrentTypedefs(currentScope)
val currentNamespace: Name?
get() {
val namedScope = this.firstScopeIsInstanceOrNull()
return if (namedScope is NameScope) namedScope.name else null
}
init {
pushScope(GlobalScope())
}
companion object {
private val LOGGER = LoggerFactory.getLogger(ScopeManager::class.java)
}
/**
* Combines the state of several scope managers into this one. Primarily used in combination
* with concurrent frontends.
*
* @param toMerge The scope managers to merge into this one
*/
fun mergeFrom(toMerge: Collection) {
val globalScopes = toMerge.mapNotNull { it.globalScope }
val currGlobalScope = scopeMap[null]
if (currGlobalScope !is GlobalScope) {
LOGGER.error("Scope for null node is not a GlobalScope or is null")
} else {
currGlobalScope.mergeFrom(globalScopes)
scopeMap[null] = currGlobalScope
}
for (manager in toMerge) {
// loop through all scopes in the FQN map to check for potential duplicates we need to
// merge
for (entry in manager.fqnScopeMap.entries) {
val existing = fqnScopeMap[entry.key]
if (existing != null) {
// a name scope with an identical FQN already exist. we transfer all
// declarations over to it. We are NOT using [addValueDeclaration] because this
// will add it to the underlying AST node as well. This was already done by the
// respective sub-scope manager. We add it directly to the declarations array
// instead.
existing.valueDeclarations.addAll(entry.value.valueDeclarations)
existing.structureDeclarations.addAll(entry.value.structureDeclarations)
// copy over the typedefs as well just to be sure
existing.typedefs.putAll(entry.value.typedefs)
// also update the AST node of the existing scope to the "latest" we have seen
existing.astNode = entry.value.astNode
// now it gets more tricky. we also need to "redirect" the AST nodes in the sub
// scope manager to our
// existing NameScope (currently, they point to their own, invalid copy of the
// NameScope).
//
// The only way to do this, is to filter for the particular
// scope (the value of the map) and return the keys (the nodes)
val keys =
manager.scopeMap
.filter { it.value.astNode == entry.value.astNode }
.map { it.key }
// now, we redirect it to the existing scope
keys.forEach { manager.scopeMap[it] = existing }
} else {
// this is the first we see for this particular FQN, so we add it to our map
fqnScopeMap[entry.key] = entry.value
}
}
// We need to make sure that we do not put the "null" key (aka the global scope) of the
// individual scope manager into our map, otherwise we would overwrite our merged global
// scope.
scopeMap.putAll(manager.scopeMap.filter { it.key != null })
// free the maps, just to clear up some things. this scope manager will not be used
// anymore
manager.fqnScopeMap.clear()
manager.scopeMap.clear()
}
}
/**
* Pushes the scope on the current scope stack. Used internally by [enterScope].
*
* @param scope the scope
*/
private fun pushScope(scope: Scope) {
if (scopeMap.containsKey(scope.astNode)) {
LOGGER.error(
"Node cannot be scoped twice. A node must be at most one associated scope apart from the parent scopes."
)
return
}
scopeMap[scope.astNode] = scope
if (scope is NameScope) {
// for this to work, it is essential that RecordDeclaration and NamespaceDeclaration
// nodes have a FQN as their name.
fqnScopeMap[scope.astNode?.name.toString()] = scope
}
currentScope?.let {
it.children.add(scope)
scope.parent = it
}
currentScope = scope
}
/**
* This function, in combination with [leaveScope] is the main interaction point with the scope
* manager for language frontends. Every time a language frontend handles a node that begins a
* new scope, this function needs to be called. Appropriate scopes will then be created
* on-the-fly, if they do not exist.
*
* The scope manager has an internal association between the type of scope, e.g. a [BlockScope]
* and the CPG node it represents, e.g. a [Block].
*
* Afterwards, all calls to [addDeclaration] will be distributed to the
* [de.fraunhofer.aisec.cpg.graph.DeclarationHolder] that is currently in-scope.
*/
fun enterScope(nodeToScope: Node) {
var newScope: Scope? = null
// check, if the node does not have an entry in the scope map
if (!scopeMap.containsKey(nodeToScope)) {
newScope =
when (nodeToScope) {
is Block -> BlockScope(nodeToScope)
is WhileStatement,
is DoStatement,
is AssertStatement -> LoopScope(nodeToScope as Statement)
is ForStatement,
is ForEachStatement -> LoopScope(nodeToScope as Statement)
is SwitchStatement -> SwitchScope(nodeToScope)
is FunctionDeclaration -> FunctionScope(nodeToScope)
is IfStatement -> ValueDeclarationScope(nodeToScope)
is CatchClause -> ValueDeclarationScope(nodeToScope)
is RecordDeclaration -> RecordScope(nodeToScope)
is TemplateDeclaration -> TemplateScope(nodeToScope)
is TryStatement -> TryScope(nodeToScope)
is NamespaceDeclaration -> newNameScopeIfNecessary(nodeToScope)
else -> {
LOGGER.error(
"No known scope for AST node of type {}",
nodeToScope.javaClass
)
return
}
}
}
// push the new scope
if (newScope != null) {
pushScope(newScope)
newScope.scopedName = currentNamespace?.toString()
} else {
currentScope = scopeMap[nodeToScope]
}
}
/**
* A small internal helper function used by [enterScope] to create a [NameScope].
*
* The issue with name scopes, such as a namespace, is that it can exist across several files,
* i.e. translation units, represented by different [NamespaceDeclaration] nodes. But, in order
* to make namespace resolution work across files, only one [NameScope] must exist that holds
* all declarations, such as classes, independently of the translation units. Therefore, we need
* to check, whether such as node already exists. If it does already exist:
* - we update the scope map so that the current [NamespaceDeclaration] points to the existing
* [NameScope]
* - we return null, indicating to [enterScope], that no new scope needs to be pushed by
* [enterScope].
*
* Otherwise, we return a new name scope.
*/
private fun newNameScopeIfNecessary(nodeToScope: NamespaceDeclaration): NameScope? {
val existingScope =
currentScope?.children?.firstOrNull { it is NameScope && it.name == nodeToScope.name }
return if (existingScope != null) {
// update the AST node to this namespace declaration
existingScope.astNode = nodeToScope
// make it also available in the scope map. Otherwise, we cannot leave the
// scope
scopeMap[nodeToScope] = existingScope
// do NOT return a new name scope, but rather return null, so enterScope knows that it
// does not need to push a new scope
null
} else {
NameScope(nodeToScope)
}
}
/**
* Similar to [enterScope], but does so in a "read-only" mode, e.g. it does not modify the scope
* tree and does not create new scopes on the fly, as [enterScope] does.
*/
fun enterScopeIfExists(nodeToScope: Node?) {
if (scopeMap.containsKey(nodeToScope)) {
val scope = scopeMap[nodeToScope]
// we need a special handling of name spaces, because
// they are associated to more than one AST node
if (scope is NameScope) {
// update AST (see enterScope for an explanation)
scope.astNode = nodeToScope
}
currentScope = scope
}
}
/**
* The counter-part of [enterScope]. Language frontends need to call this function, when the
* scope of the currently processed AST node ends. There MUST have been a corresponding
* [enterScope] call with the same [nodeToLeave], otherwise the scope-tree might be corrupted.
*
* @param nodeToLeave the AST node
* @return the scope that was just left
*/
fun leaveScope(nodeToLeave: Node): Scope? {
// Check to return as soon as we know that there is no associated scope. This check could be
// omitted but will increase runtime if leaving a node without scope will happen often.
if (!scopeMap.containsKey(nodeToLeave)) {
return null
}
val leaveScope = firstScopeOrNull { it.astNode == nodeToLeave }
if (leaveScope == null) {
if (scopeMap.containsKey(nodeToLeave)) {
Util.errorWithFileLocation(
nodeToLeave,
LOGGER,
"Node of type {} has a scope but is not active in the moment.",
nodeToLeave.javaClass
)
} else {
Util.errorWithFileLocation(
nodeToLeave,
LOGGER,
"Node of type {} is not associated with a scope.",
nodeToLeave.javaClass
)
}
return null
}
// go back to the parent of the scope we just left
currentScope = leaveScope.parent
return leaveScope
}
/**
* This function MUST be called when a language frontend first handles a [Declaration]. It adds
* a declaration to the scope manager, taking into account the currently active scope.
* Furthermore, it adds the declaration to the [de.fraunhofer.aisec.cpg.graph.DeclarationHolder]
* that is associated with the current scope through [ValueDeclarationScope.addValueDeclaration]
* and [StructureDeclarationScope.addStructureDeclaration].
*
* Setting [Scope.astNode] to false is useful, if you want to make sure a certain declaration is
* visible within a scope, but is not directly part of the scope's AST. An example is the way
* C/C++ handles unscoped enum constants. They are visible in the enclosing scope, e.g., a
* translation unit, but they are added to the AST of their enum declaration, not the
* translation unit. The enum declaration is then added to the translation unit.
*
* @param declaration the declaration to add
* @param addToAST specifies, whether the declaration also gets added to the [Scope.astNode] of
* the current scope (if it implements [DeclarationHolder]). Defaults to true.
*/
@JvmOverloads
fun addDeclaration(declaration: Declaration?, addToAST: Boolean = true) {
when (declaration) {
is ProblemDeclaration,
is IncludeDeclaration -> {
// directly add problems and includes to the global scope
this.globalScope?.addDeclaration(declaration, addToAST)
}
is ValueDeclaration -> {
val scope = this.firstScopeIsInstanceOrNull()
scope?.addValueDeclaration(declaration, addToAST)
}
is RecordDeclaration,
is NamespaceDeclaration,
is EnumDeclaration,
is TemplateDeclaration -> {
val scope = this.firstScopeIsInstanceOrNull()
scope?.addDeclaration(declaration, addToAST)
}
}
}
/**
* This function tries to find the first scope that satisfies the condition specified in
* [predicate]. It starts searching in the [searchScope], moving up-wards using the
* [Scope.parent] attribute.
*
* @param searchScope the scope to start the search in
* @param predicate the search predicate
*/
@JvmOverloads
fun firstScopeOrNull(searchScope: Scope? = currentScope, predicate: Predicate): Scope? {
// start at searchScope
var scope = searchScope
while (scope != null) {
if (predicate.test(scope)) {
return scope
}
// go up-wards in the scope tree
scope = scope.parent
}
return null
}
/**
* Tries to find the first scope that is an instance of the scope type [T]. Calls
* [firstScopeOrNull] internally.
*
* @param searchScope the scope to start the search in
*/
inline fun firstScopeIsInstanceOrNull(
searchScope: Scope? = currentScope
): T? {
return this.firstScopeOrNull(searchScope) { it is T } as? T
}
/**
* Retrieves all unique scopes that satisfy the condition specified in [predicate],
* independently of their hierarchy.
*
* @param predicate the search predicate
*/
fun filterScopes(predicate: (Scope) -> Boolean): List {
return scopeMap.values.filter(predicate).distinct()
}
/** This function returns the [Scope] associated with a node. */
fun lookupScope(node: Node): Scope? {
return if (node is TranslationUnitDeclaration) {
globalScope
} else scopeMap[node]
}
/** This function looks up scope by its FQN. This only works for [NameScope]s */
fun lookupScope(fqn: String): NameScope? {
return this.fqnScopeMap[fqn]
}
/**
* This function SHOULD only be used by the
* [de.fraunhofer.aisec.cpg.passes.EvaluationOrderGraphPass] while building up the EOG. It adds
* a [BreakStatement] to the list of break statements of the current "breakable" scope.
*/
fun addBreakStatement(breakStatement: BreakStatement) {
if (breakStatement.label == null) {
val scope = firstScopeOrNull { scope: Scope? -> scope?.isBreakable() == true }
if (scope == null) {
Util.errorWithFileLocation(
breakStatement,
LOGGER,
"Break inside of unbreakable scope. The break will be ignored, but may lead " +
"to an incorrect graph. The source code is not valid or incomplete."
)
return
}
(scope as Breakable).addBreakStatement(breakStatement)
} else {
val labelStatement = getLabelStatement(breakStatement.label)
labelStatement?.subStatement?.let {
val scope = lookupScope(it)
(scope as Breakable?)?.addBreakStatement(breakStatement)
}
}
}
/**
* This function SHOULD only be used by the
* [de.fraunhofer.aisec.cpg.passes.EvaluationOrderGraphPass] while building up the EOG. It adds
* a [ContinueStatement] to the list of continue statements of the current "continuable" scope.
*/
fun addContinueStatement(continueStatement: ContinueStatement) {
if (continueStatement.label == null) {
val scope = firstScopeOrNull { scope: Scope? -> scope?.isContinuable() == true }
if (scope == null) {
LOGGER.error(
"Continue inside of not continuable scope. The continue will be ignored, but may lead " +
"to an incorrect graph. The source code is not valid or incomplete."
)
return
}
(scope as Continuable).addContinueStatement(continueStatement)
} else {
val labelStatement = getLabelStatement(continueStatement.label)
labelStatement?.subStatement?.let {
val scope = lookupScope(it)
(scope as Continuable?)?.addContinueStatement(continueStatement)
}
}
}
/**
* This function SHOULD only be used by the
* [de.fraunhofer.aisec.cpg.passes.EvaluationOrderGraphPass] while building up the EOG. It adds
* a [LabelStatement] to the list of label statements of the current scope.
*/
fun addLabelStatement(labelStatement: LabelStatement) {
currentScope?.addLabelStatement(labelStatement)
}
/**
* This function is internal to the scope manager and primarily used by [addBreakStatement] and
* [addContinueStatement]. It retrieves the [LabelStatement] associated with the [labelString].
*/
private fun getLabelStatement(labelString: String?): LabelStatement? {
if (labelString == null) return null
var labelStatement: LabelStatement?
var searchScope = currentScope
while (searchScope != null) {
labelStatement = searchScope.labelStatements[labelString]
if (labelStatement != null) {
return labelStatement
}
searchScope = searchScope.parent
}
return null
}
/**
* This function MUST be called when a language frontend first enters a translation unit. It
* sets the [GlobalScope] to the current translation unit specified in [declaration].
*/
fun resetToGlobal(declaration: TranslationUnitDeclaration?) {
val global = this.globalScope
if (global != null) {
// update the AST node to this translation unit declaration
global.astNode = declaration
currentScope = global
}
}
/** Only used by the [TypeManager], adds typedefs to the current [ValueDeclarationScope]. */
fun addTypedef(typedef: TypedefDeclaration) {
val scope = this.firstScopeIsInstanceOrNull()
if (scope == null) {
LOGGER.error("Cannot add typedef. Not in declaration scope.")
return
}
scope.addTypedef(typedef)
}
private fun getCurrentTypedefs(searchScope: Scope?): Collection {
val typedefs = mutableMapOf()
val path = mutableListOf()
var current = searchScope
// We need to build a path from the current scope to the top most one
while (current != null) {
if (current is ValueDeclarationScope) {
path += current
}
current = current.parent
}
// And then follow the path in reverse. This ensures us that a local definition
// overwrites / shadows one that was there on a higher scope.
for (scope in path.reversed()) {
typedefs.putAll(scope.typedefs)
}
return typedefs.values
}
/**
* Resolves only references to Values in the current scope, static references to other visible
* records are not resolved over the ScopeManager.
*
* @param ref
* @return
*
* TODO: We should merge this function with [.resolveFunction]
*/
fun resolveReference(ref: Reference): ValueDeclaration? {
val startScope = ref.scope
// Retrieve a unique tag for the particular reference based on the current scope
val tag = ref.referenceTag
// If we find a match in our symbol table, we can immediately return the declaration. We
// need to be careful about potential collisions in our tags, since they are based on the
// hash-code of the scope. We therefore take the extra precaution to compare the scope in
// case we get a hit. This should not take too much performance overhead.
val pair = symbolTable[tag]
if (pair != null && ref.scope == pair.first.scope) {
return pair.second
}
val (scope, name) = extractScope(ref, startScope)
// Try to resolve value declarations according to our criteria
val decl =
resolve(scope) {
if (it.name.lastPartsMatch(name)) {
val helper = ref.resolutionHelper
return@resolve when {
// If the reference seems to point to a function (using a function
// pointer) the entire signature is checked for equality
helper?.type is FunctionPointerType && it is FunctionDeclaration -> {
val fptrType = helper.type as FunctionPointerType
// TODO(oxisto): Support multiple return values
val returnType = it.returnTypes.firstOrNull() ?: IncompleteType()
returnType == fptrType.returnType &&
it.hasSignature(fptrType.parameters)
}
// If our language has first-class functions, we can safely return them
// as a reference
ref.language is HasFirstClassFunctions -> {
true
}
// Otherwise, we are not looking for functions here
else -> {
it !is FunctionDeclaration
}
}
}
return@resolve false
}
.firstOrNull()
// Update the symbol cache, if we found a declaration for the tag
if (decl != null) {
symbolTable[tag] = Pair(ref, decl)
}
return decl
}
/**
* Tries to resolve a function in a call expression.
*
* @param call the call expression
* @return a list of possible functions
*/
@JvmOverloads
fun resolveFunction(
call: CallExpression,
startScope: Scope? = currentScope
): List {
val (scope, name) = extractScope(call, startScope)
val func =
resolve(scope) {
it.name.lastPartsMatch(name) && it.hasSignature(call)
}
return func
}
/**
* This function extracts a possible scope out of a [Name], e.g. if the name is fully qualified.
* This also resolves possible name aliases (e.g. because of imports). It returns a pair of a
* scope (if found) as well as the name, which is possibly adjusted for the aliases.
*
* Note: Currently only *fully* qualified names are properly resolved. This function will
* probably return imprecise results for partially qualified names, e.g. if a name `A` inside
* `B` points to `A::B`, rather than to `A`.
*/
fun extractScope(node: Node, scope: Scope? = currentScope): Pair {
var name: Name = node.name
var s = scope
// First, we need to check, whether we have some kind of scoping.
if (node.name.isQualified()) {
// extract the scope name, it is usually a name space, but could probably be something
// else as well in other languages
var scopeName = node.name.parent
// We need to check, whether we have an alias for the scope name in this file
val list = aliases[node.location?.artifactLocation]
val alias = list?.firstOrNull { it.to == scopeName }?.from
if (alias != null) {
scopeName = alias
// Reconstruct the original name with the alias, so we can resolve declarations with
// the namespace
name = Name(name.localName, alias)
}
// this is a scoped call. we need to explicitly jump to that particular scope
val scopes = filterScopes { (it is NameScope && it.name == scopeName) }
s =
if (scopes.isEmpty()) {
Util.errorWithFileLocation(
node,
LOGGER,
"Could not find the scope $scopeName needed to resolve the call ${node.name}"
)
scope
} else {
scopes[0]
}
}
return Pair(s, name)
}
/**
* Directly jumps to a given scope. Returns the previous scope. Do not forget to set the scope
* back to the old scope after performing the actions inside this scope.
*
* Handle with care, here be dragons. Should not be exposed outside the cpg-core module.
*/
@PleaseBeCareful
internal fun jumpTo(scope: Scope?): Scope? {
val oldScope = currentScope
currentScope = scope
return oldScope
}
/**
* This function can be used to execute multiple statements contained in [init] in the scope of
* [scope]. The specified scope will be selected using [jumpTo]. The last expression in [init]
* will also be used as a return value of this function. This can be useful, if you create
* objects, such as a [Node] inside this scope and want to return it to the calling function.
*/
fun withScope(scope: Scope?, init: () -> T): T {
val oldScope = jumpTo(scope)
val ret = init()
jumpTo(oldScope)
return ret
}
fun resolveFunctionStopScopeTraversalOnDefinition(
call: CallExpression
): List {
return resolve(currentScope, true) { f -> f.name.lastPartsMatch(call.name) }
}
/**
* Traverses the scope upwards and looks for declarations of type [T] which matches the
* condition [predicate].
*
* It returns a list of all declarations that match the predicate, ordered by reachability in
* the scope stack. This means that "local" declarations will be in the list first, global items
* will be last.
*
* @param searchScope the scope to start the search in
* @param predicate predicate the element must match to
* @param
*/
inline fun resolve(
searchScope: Scope?,
stopIfFound: Boolean = false,
noinline predicate: (T) -> Boolean
): List {
return resolve(T::class.java, searchScope, stopIfFound, predicate)
}
fun resolve(
klass: Class,
searchScope: Scope?,
stopIfFound: Boolean = false,
predicate: (T) -> Boolean
): List {
var scope = searchScope
val declarations = mutableListOf()
while (scope != null) {
if (scope is ValueDeclarationScope) {
declarations.addAll(
scope.valueDeclarations.filterIsInstance(klass).filter(predicate)
)
}
if (scope is StructureDeclarationScope) {
var list = scope.structureDeclarations.filterIsInstance(klass).filter(predicate)
// this was taken over from the old resolveStructureDeclaration.
// TODO(oxisto): why is this only when the list is empty?
if (list.isEmpty()) {
for (declaration in scope.structureDeclarations) {
if (declaration is RecordDeclaration) {
list = declaration.templates.filterIsInstance(klass).filter(predicate)
}
}
}
declarations.addAll(list)
}
// some (all?) languages require us to stop immediately if we found something on this
// scope. This is the case where function overloading is allowed, but only within the
// same scope
if (stopIfFound && declarations.isNotEmpty()) {
return declarations
}
// go upwards in the scope tree
scope = scope.parent
}
return declarations
}
/**
* Resolves function templates of the given [CallExpression].
*
* @param scope where we are searching for the FunctionTemplateDeclarations
* @param call CallExpression we want to resolve an invocation target for
* @return List of FunctionTemplateDeclaration that match the name provided in the
* CallExpression and therefore are invocation candidates
*/
@JvmOverloads
fun resolveFunctionTemplateDeclaration(
call: CallExpression,
scope: Scope? = currentScope
): List {
return resolve(scope, true) { c -> c.name.lastPartsMatch(call.name) }
}
/**
* Retrieves the [RecordDeclaration] for the given name in the given scope.
*
* @param name the name
* * @param scope the scope. Default is [currentScope]
*
* @return the declaration, or null if it does not exist
*/
fun getRecordForName(name: Name, scope: Scope? = currentScope): RecordDeclaration? {
return resolve(scope, true) { it.name.lastPartsMatch(name) }
.firstOrNull()
}
fun addAlias(file: PhysicalLocation.ArtifactLocation, from: Name, to: Name) {
val list = aliases.computeIfAbsent(file) { mutableSetOf() }
list += Alias(from, to)
}
fun typedefFor(alias: Type): Type? {
var current = currentScope
// We need to build a path from the current scope to the top most one. This ensures us that
// a local definition overwrites / shadows one that was there on a higher scope.
while (current != null) {
if (current is ValueDeclarationScope) {
val decl = current.typedefs[alias]
if (decl != null) {
return decl.type
}
}
current = current.parent
}
return null
}
/** Returns the current scope for the [ScopeProvider] interface. */
override val scope: Scope?
get() = currentScope
}