[SourceKit] Don't use C++ interop to append elements to a ResolvedLocVector

This was causing build issues on Linux with Swift 5.8. Instead, wrap the `std::vector` in a `BridgedResolvedLocVector` that has a pointer to a heap-allocated `std::vector`

Author: ahoppen

include/swift/IDE/IDEBridging.h

@@ -80,16 +80,6 @@ struct ResolvedLoc {
   ResolvedLoc();
 };
 
-typedef std::vector<ResolvedLoc> ResolvedLocVector;
-
-/// Create an empty `std::vector<ResolvedLoc>`.
-///
-/// - Note: This can't be imported as an initializer on
-/// `BridgedResolvedLocVector`
-///   because initializers without any arguments aren't imported to Swift
-SWIFT_NAME("ResolvedLocVector.empty()")
-ResolvedLocVector ResolvedLocVector_createEmpty();
-
 /// A heap-allocated `std::vector<ResoledLoc>` that can be represented by an
 /// opaque pointer value.
 ///
@@ -102,29 +92,40 @@ ResolvedLocVector ResolvedLocVector_createEmpty();
 ///   In that case `swift_SwiftIDEUtilsBridging_runNameMatcher` can return a
 ///   `ResolvedLocVector`.
 class BridgedResolvedLocVector {
-  const std::vector<ResolvedLoc> *vector;
+  friend void *BridgedResolvedLocVector_getOpaqueValue(const BridgedResolvedLocVector &vector);
+
+  std::vector<ResolvedLoc> *vector;
 
 public:
   /// Create heap-allocaed vector with the same elements as `vector`.
   BridgedResolvedLocVector(const std::vector<ResolvedLoc> &vector);
 
   /// Create a `BridgedResolvedLocVector` from an opaque value obtained from
   /// `getOpaqueValue`.
-  BridgedResolvedLocVector(const void *opaqueValue);
+  BridgedResolvedLocVector(void *opaqueValue);
+
+  void push_back(const ResolvedLoc &Loc);
 
   /// Get the underlying vector.
   const std::vector<ResolvedLoc> &unbridged();
 
   /// Delete the heap-allocated memory owned by this object. Accessing
   /// `unbridged` is illegal after calling `destroy`.
   void destroy();
-
-  /// Get an opaque pointer value that describes this 
-  /// `BridgedResolvedLocVector`. This opaque value can be returned by a
-  /// `@_cdecl` function in Swift.
-  const void *getOpaqueValue() const;
 };
 
+
+SWIFT_NAME("BridgedResolvedLocVector.empty()")
+BridgedResolvedLocVector BridgedResolvedLocVector_createEmpty();
+
+/// Get an opaque pointer value that describes this
+/// `BridgedResolvedLocVector`. This opaque value can be returned by a
+/// `@_cdecl` function in Swift.
+/// 
+/// - Note: Cannot be defined as a member on BridgedResolvecLocVector because 
+///   Swift 5.8 does not import methods that return pointers. 
+void *BridgedResolvedLocVector_getOpaqueValue(const BridgedResolvedLocVector &vector);
+
 typedef std::vector<BridgedSourceLoc> SourceLocVector;
 
 /// Needed so that we can manually conform `SourceLocVectorIterator` to

lib/ASTGen/Sources/SwiftIDEUtilsBridging/NameMatcherBridging.swift

@@ -15,19 +15,6 @@ import SwiftSyntax
 import swiftASTGen
 import IDEBridging
 
-// MARK: - SourceLocVector Sequence conformance
-
-#if swift(<5.9)
-
-/// Needed because C++ interop does not automatically conform SourceLocVector to CxxSequence with a Swift 5.8 compiler.
-extension SourceLocVectorIterator: UnsafeCxxInputIterator {
-   public static func ==(lhs: SourceLocVectorIterator, rhs: SourceLocVectorIterator) -> Bool { Self.equals(lhs, rhs) }
-}
-extension SourceLocVector: CxxSequence {
-  public typealias RawIterator = SourceLocVectorIterator
-}
-#endif
-
 // MARK: - Bridged type initializers
 
 fileprivate extension BridgedCharSourceRange {
@@ -48,7 +35,7 @@ fileprivate extension CharSourceRangeVector {
   }
 }
 
-fileprivate extension ResolvedLocVector {
+fileprivate extension BridgedResolvedLocVector {
   init(from resolvedLocs: some Sequence<DeclNameLocation>, in sourceFile: ExportedSourceFile) {
     self = .empty()
     for resolvedLoc in resolvedLocs {
@@ -114,10 +101,11 @@ public func runNameMatcher(
   sourceFilePtr: UnsafeRawPointer,
   locations: UnsafePointer<BridgedSourceLoc>,
   locationsCount: UInt
-) -> UnsafeRawPointer {
+) -> UnsafeMutableRawPointer? {
   let sourceFile = sourceFilePtr.bindMemory(to: ExportedSourceFile.self, capacity: 1).pointee
   let locations = UnsafeBufferPointer(start: locations, count: Int(locationsCount))
   let positions: [AbsolutePosition] =  locations.compactMap { sourceFile.position(of: $0) }
   let resolvedLocs = NameMatcher.resolve(baseNamePositions: positions, in: sourceFile.syntax)
-  return BridgedResolvedLocVector(ResolvedLocVector(from: resolvedLocs, in: sourceFile)).getOpaqueValue()
+  let bridged = BridgedResolvedLocVector(from: resolvedLocs, in: sourceFile)
+  return BridgedResolvedLocVector_getOpaqueValue(bridged)
 }

lib/IDE/IDEBridging.cpp

@@ -35,23 +35,27 @@ ResolvedLoc::ResolvedLoc(swift::CharSourceRange range,
 
 ResolvedLoc::ResolvedLoc() {}
 
-ResolvedLocVector ResolvedLocVector_createEmpty() {
-  return ResolvedLocVector();
+BridgedResolvedLocVector BridgedResolvedLocVector_createEmpty() {
+  return BridgedResolvedLocVector(new std::vector<ResolvedLoc>());
+}
+
+void BridgedResolvedLocVector::push_back(const ResolvedLoc &Loc) {
+  this->vector->push_back(Loc);
 }
 
 BridgedResolvedLocVector::BridgedResolvedLocVector(
     const std::vector<ResolvedLoc> &vector)
     : vector(new std::vector<ResolvedLoc>(vector)) {}
 
-BridgedResolvedLocVector::BridgedResolvedLocVector(const void *opaqueValue)
-    : vector(static_cast<const std::vector<ResolvedLoc> *>(opaqueValue)) {}
+BridgedResolvedLocVector::BridgedResolvedLocVector(void *opaqueValue)
+    : vector(static_cast<std::vector<ResolvedLoc> *>(opaqueValue)) {}
 
 const std::vector<ResolvedLoc> &BridgedResolvedLocVector::unbridged() {
   return *vector;
 }
 
 void BridgedResolvedLocVector::destroy() { delete vector; }
 
-const void *BridgedResolvedLocVector::getOpaqueValue() const {
-  return static_cast<const void *>(vector);
+void *BridgedResolvedLocVector_getOpaqueValue(const BridgedResolvedLocVector &vector) {
+  return static_cast<void *>(vector.vector);
 }