Merge branch 'master' of github.com:apple/swift into autodiff-upstream-stdlib-differentiation

Author: dan-zheng

include/swift/AST/ClangModuleLoader.h

@@ -128,7 +128,9 @@ class ClangModuleLoader : public ModuleLoader {
 
   /// Retrieves the Swift wrapper for the given Clang module, creating
   /// it if necessary.
-  virtual ModuleDecl *getWrapperForModule(const clang::Module *mod) const = 0;
+  virtual ModuleDecl *
+  getWrapperForModule(const clang::Module *mod,
+                      bool returnOverlayIfPossible = false) const = 0;
 
   /// Adds a new search path to the Clang CompilerInstance, as if specified with
   /// -I or -F.

include/swift/AST/DiagnosticsSIL.def

@@ -512,6 +512,8 @@ NOTE(autodiff_cannot_param_subset_thunk_partially_applied_orig_fn,none,
      "function; use an explicit closure instead", ())
 NOTE(autodiff_cannot_differentiate_through_multiple_results,none,
      "cannot differentiate through multiple results", ())
+NOTE(autodiff_cannot_differentiate_through_inout_arguments,none,
+     "cannot differentiate through 'inout' arguments", ())
 // TODO(TF-1149): Remove this diagnostic.
 NOTE(autodiff_loadable_value_addressonly_tangent_unsupported,none,
      "cannot yet differentiate value whose type %0 has a compile-time known "

include/swift/AST/DiagnosticsSema.def

@@ -585,6 +585,9 @@ ERROR(expr_swift_keypath_invalid_component,none,
       "invalid component of Swift key path", ())
 ERROR(expr_swift_keypath_not_starting_with_type,none,
       "a Swift key path must begin with a type", ())
+ERROR(expr_swift_keypath_not_starting_with_dot,none,
+      "a Swift key path with contextual root must begin with a leading dot",
+      ())
 ERROR(expr_smart_keypath_value_covert_to_contextual_type,none,
       "key path value type %0 cannot be converted to contextual type %1",
       (Type, Type))

include/swift/AST/Expr.h

@@ -5035,6 +5035,10 @@ class KeyPathExpr : public Expr {
   // The processed/resolved type, like Foo.Bar in \Foo.Bar.?.baz.
   TypeRepr *RootType = nullptr;
 
+  /// Determines whether a key path starts with '.' which denotes necessity for
+  /// a contextual root type.
+  bool HasLeadingDot = false;
+
 public:
   /// A single stored component, which will be one of:
   /// - an unresolved DeclNameRef, which has to be type-checked
@@ -5396,10 +5400,11 @@ class KeyPathExpr : public Expr {
               bool isImplicit = false);
 
   KeyPathExpr(SourceLoc backslashLoc, Expr *parsedRoot, Expr *parsedPath,
-              bool isImplicit = false)
+              bool hasLeadingDot, bool isImplicit = false)
       : Expr(ExprKind::KeyPath, isImplicit), StartLoc(backslashLoc),
         EndLoc(parsedPath ? parsedPath->getEndLoc() : parsedRoot->getEndLoc()),
-        ParsedRoot(parsedRoot), ParsedPath(parsedPath) {
+        ParsedRoot(parsedRoot), ParsedPath(parsedPath),
+        HasLeadingDot(hasLeadingDot) {
     assert((parsedRoot || parsedPath) &&
            "keypath must have either root or path");
     Bits.KeyPathExpr.IsObjC = false;
@@ -5463,6 +5468,9 @@ class KeyPathExpr : public Expr {
   /// True if this is an ObjC key path expression.
   bool isObjC() const { return Bits.KeyPathExpr.IsObjC; }
 
+  /// True if this key path expression has a leading dot.
+  bool expectsContextualRoot() const { return HasLeadingDot; }
+
   static bool classof(const Expr *E) {
     return E->getKind() == ExprKind::KeyPath;
   }

include/swift/AST/Module.h

@@ -465,7 +465,7 @@ class ModuleDecl : public DeclContext, public TypeDecl {
   /// Retrieve the top-level module. If this module is already top-level, this
   /// returns itself. If this is a submodule such as \c Foo.Bar.Baz, this
   /// returns the module \c Foo.
-  ModuleDecl *getTopLevelModule();
+  ModuleDecl *getTopLevelModule(bool overlay = false);
 
   bool isResilient() const {
     return getResilienceStrategy() != ResilienceStrategy::Default;

include/swift/ClangImporter/ClangImporter.h

@@ -330,7 +330,9 @@ class ClangImporter final : public ClangModuleLoader {
 
   /// Retrieves the Swift wrapper for the given Clang module, creating
   /// it if necessary.
-  ModuleDecl *getWrapperForModule(const clang::Module *mod) const override;
+  ModuleDecl *
+  getWrapperForModule(const clang::Module *mod,
+                      bool returnOverlayIfPossible = false) const override;
 
   std::string getBridgingHeaderContents(StringRef headerPath, off_t &fileSize,
                                         time_t &fileModTime);

include/swift/ClangImporter/SwiftAbstractBasicReader.h

@@ -19,6 +19,7 @@
 #ifndef SWIFT_CLANGIMPORTER_SWIFTABSTRACTBASICREADER_H
 #define SWIFT_CLANGIMPORTER_SWIFTABSTRACTBASICREADER_H
 
+#include "clang/AST/ASTContext.h"
 #include "clang/AST/AbstractTypeReader.h"
 
 // This include is required to instantiate the template code in

include/swift/SILOptimizer/Utils/Differentiation/AdjointValue.h

@@ -148,7 +148,7 @@ class AdjointValue final {
               std::get<1>(elt).print(s);
             },
             [&s] { s << ", "; });
-      } else if (auto tupleType = getType().getAs<TupleType>()) {
+      } else if (getType().is<TupleType>()) {
         s << "Tuple>(";
         interleave(
             base->value.aggregate,