Implement experimental module selectors (MyMod::someName) feature

include/swift/AST/ASTBridging.h

@@ -198,10 +198,13 @@ BridgedDeclNameRef_createParsed(BridgedDeclBaseName cBaseName);
 
 class BridgedDeclNameLoc {
   const void *_Nullable LocationInfo;
-  size_t NumArgumentLabels;
+  uint32_t NumArgumentLabels;
+  bool HasModuleSelectorLoc;
 
 public:
-  BridgedDeclNameLoc() : LocationInfo(nullptr), NumArgumentLabels(0) {}
+  BridgedDeclNameLoc()
+    : LocationInfo(nullptr), NumArgumentLabels(0), HasModuleSelectorLoc(false)
+  {}
 
   BRIDGED_INLINE BridgedDeclNameLoc(swift::DeclNameLoc loc);
 
@@ -1015,11 +1018,12 @@ BridgedDocumentationAttr BridgedDocumentationAttr_createParsed(
 
 SWIFT_NAME(
     "BridgedDynamicReplacementAttr.createParsed(_:atLoc:attrNameLoc:lParenLoc:"
-    "replacedFunction:rParenLoc:)")
+    "replacedFunction:replacedFunctionLoc:rParenLoc:)")
 BridgedDynamicReplacementAttr BridgedDynamicReplacementAttr_createParsed(
     BridgedASTContext cContext, BridgedSourceLoc cAtLoc,
     BridgedSourceLoc cAttrNameLoc, BridgedSourceLoc cLParenLoc,
-    BridgedDeclNameRef cReplacedFunction, BridgedSourceLoc cRParenLoc);
+    BridgedDeclNameRef cReplacedFunction,
+    BridgedDeclNameLoc cReplacedFunctionLoc, BridgedSourceLoc cRParenLoc);
 
 enum ENUM_EXTENSIBILITY_ATTR(closed) BridgedEffectsKind {
   BridgedEffectsKindReadNone,
@@ -1388,13 +1392,14 @@ enum ENUM_EXTENSIBILITY_ATTR(closed) BridgedSpecializationKind : uint8_t {
 };
 
 SWIFT_NAME("BridgedSpecializeAttr.createParsed(_:atLoc:range:whereClause:"
-           "exported:kind:taretFunction:spiGroups:availableAttrs:)")
+           "exported:kind:targetFunction:targetFunctionLoc:spiGroups:"
+           "availableAttrs:)")
 BridgedSpecializeAttr BridgedSpecializeAttr_createParsed(
     BridgedASTContext cContext, BridgedSourceLoc cAtLoc,
     BridgedSourceRange cRange, BridgedNullableTrailingWhereClause cWhereClause,
     bool exported, BridgedSpecializationKind cKind,
-    BridgedDeclNameRef cTargetFunction, BridgedArrayRef cSPIGroups,
-    BridgedArrayRef cAvailableAttrs);
+    BridgedDeclNameRef cTargetFunction, BridgedDeclNameLoc cTargetFunctionLoc,
+    BridgedArrayRef cSPIGroups, BridgedArrayRef cAvailableAttrs);
 
 SWIFT_NAME(
     "BridgedSPIAccessControlAttr.createParsed(_:atLoc:range:spiGroupName:)")

include/swift/AST/ASTBridgingImpl.h

@@ -87,10 +87,12 @@ swift::DeclNameRef BridgedDeclNameRef::unbridged() const {
 
 BridgedDeclNameLoc::BridgedDeclNameLoc(swift::DeclNameLoc loc)
     : LocationInfo(loc.LocationInfo),
-      NumArgumentLabels(loc.NumArgumentLabels) {}
+      NumArgumentLabels(loc.NumArgumentLabels),
+      HasModuleSelectorLoc(loc.HasModuleSelectorLoc) {}
 
 swift::DeclNameLoc BridgedDeclNameLoc::unbridged() const {
-  return swift::DeclNameLoc(LocationInfo, NumArgumentLabels);
+  return swift::DeclNameLoc(LocationInfo, NumArgumentLabels,
+                            HasModuleSelectorLoc);
 }
 
 //===----------------------------------------------------------------------===//

include/swift/AST/Attr.h

@@ -1207,19 +1207,22 @@ class DynamicReplacementAttr final
   friend class DynamicallyReplacedDeclRequest;
 
   DeclNameRef ReplacedFunctionName;
+  DeclNameLoc ReplacedFunctionNameLoc;
   LazyMemberLoader *Resolver = nullptr;
   uint64_t ResolverContextData;
 
   /// Create an @_dynamicReplacement(for:) attribute written in the source.
   DynamicReplacementAttr(SourceLoc atLoc, SourceRange baseRange,
                          DeclNameRef replacedFunctionName,
+                         DeclNameLoc replacedFunctionNameLoc,
                          SourceRange parenRange);
 
   DynamicReplacementAttr(DeclNameRef name, AbstractFunctionDecl *f)
       : DeclAttribute(DeclAttrKind::DynamicReplacement, SourceLoc(),
                       SourceRange(),
                       /*Implicit=*/false),
-        ReplacedFunctionName(name), Resolver(nullptr), ResolverContextData(0) {
+        ReplacedFunctionName(name), ReplacedFunctionNameLoc(),
+        Resolver(nullptr), ResolverContextData(0) {
     Bits.DynamicReplacementAttr.HasTrailingLocationInfo = false;
   }
 
@@ -1228,8 +1231,8 @@ class DynamicReplacementAttr final
       : DeclAttribute(DeclAttrKind::DynamicReplacement, SourceLoc(),
                       SourceRange(),
                       /*Implicit=*/false),
-        ReplacedFunctionName(name), Resolver(Resolver),
-        ResolverContextData(Data) {
+        ReplacedFunctionName(name), ReplacedFunctionNameLoc(),
+        Resolver(Resolver), ResolverContextData(Data) {
     Bits.DynamicReplacementAttr.HasTrailingLocationInfo = false;
   }
 
@@ -1250,7 +1253,8 @@ class DynamicReplacementAttr final
 public:
   static DynamicReplacementAttr *
   create(ASTContext &Context, SourceLoc AtLoc, SourceLoc DynReplLoc,
-         SourceLoc LParenLoc, DeclNameRef replacedFunction, SourceLoc RParenLoc);
+         SourceLoc LParenLoc, DeclNameRef replacedFunction,
+         DeclNameLoc replacedFunctionNameLoc, SourceLoc RParenLoc);
 
   static DynamicReplacementAttr *create(ASTContext &ctx,
                                         DeclNameRef replacedFunction,
@@ -1265,6 +1269,10 @@ class DynamicReplacementAttr final
     return ReplacedFunctionName;
   }
 
+  DeclNameLoc getReplacedFunctionNameLoc() const {
+    return ReplacedFunctionNameLoc;
+  }
+
   /// Retrieve the location of the opening parentheses, if there is one.
   SourceLoc getLParenLoc() const;
 
@@ -1752,6 +1760,7 @@ class SpecializeAttr final
   GenericSignature specializedSignature;
 
   DeclNameRef targetFunctionName;
+  DeclNameLoc targetFunctionNameLoc;
   LazyMemberLoader *resolver = nullptr;
   uint64_t resolverContextData;
   size_t numSPIGroups;
@@ -1762,15 +1771,18 @@ class SpecializeAttr final
   SpecializeAttr(SourceLoc atLoc, SourceRange Range,
                  TrailingWhereClause *clause, bool exported,
                  SpecializationKind kind, GenericSignature specializedSignature,
-                 DeclNameRef targetFunctionName, ArrayRef<Identifier> spiGroups,
+                 DeclNameRef targetFunctionName,
+                 DeclNameLoc targetFunctionNameLoc,
+                 ArrayRef<Identifier> spiGroups,
                  ArrayRef<AvailableAttr *> availabilityAttrs,
                  size_t typeErasedParamsCount);
 
 public:
   static SpecializeAttr *
   create(ASTContext &Ctx, SourceLoc atLoc, SourceRange Range,
          TrailingWhereClause *clause, bool exported, SpecializationKind kind,
-         DeclNameRef targetFunctionName, ArrayRef<Identifier> spiGroups,
+         DeclNameRef targetFunctionName, DeclNameLoc targetFunctionNameLoc,
+         ArrayRef<Identifier> spiGroups,
          ArrayRef<AvailableAttr *> availabilityAttrs,
          GenericSignature specializedSignature = nullptr);
 
@@ -1849,6 +1861,10 @@ class SpecializeAttr final
     return targetFunctionName;
   }
 
+  DeclNameLoc getTargetFunctionNameLoc() const {
+    return targetFunctionNameLoc;
+  }
+
   /// \p forDecl is the value decl that the attribute belongs to.
   ValueDecl *getTargetFunctionDecl(const ValueDecl *forDecl) const;
 

include/swift/AST/Decl.h

@@ -2995,11 +2995,10 @@ class ValueDecl : public Decl {
     return Name.getBaseIdentifier();
   }
 
-  /// Generates a DeclNameRef referring to this declaration with as much
-  /// specificity as possible.
-  DeclNameRef createNameRef() const {
-    return DeclNameRef(Name);
-  }
+  /// Generates a DeclNameRef referring to this declaration.
+  ///
+  /// \param moduleSelector If true, the name ref includes the module name.
+  DeclNameRef createNameRef(bool moduleSelector = false) const;
 
   /// Retrieve the C declaration name that names this function, or empty
   /// string if it has none.

include/swift/AST/DeclNameLoc.h

@@ -35,61 +35,69 @@ class DeclNameLoc {
 
   /// Source location information.
   ///
-  /// If \c NumArgumentLabels == 0, this is the SourceLoc for the base name.
-  /// Otherwise, it points to an array of SourceLocs, which contains:
+  /// If \c NumArgumentLabels == 0 and \c !HasModuleSelectorLoc, this is the
+  /// SourceLoc for the base name. Otherwise, it points to an array of
+  /// SourceLocs, which contains:
   /// * The base name location
+  /// * The module selector location
   /// * The left parentheses location
   /// * The right parentheses location
   /// * The locations of each of the argument labels.
   const void *LocationInfo;
 
   /// The number of argument labels stored in the name.
-  unsigned NumArgumentLabels;
+  uint32_t NumArgumentLabels;
+  bool HasModuleSelectorLoc;
 
   enum {
     BaseNameIndex = 0,
-    LParenIndex = 1,
-    RParenIndex = 2,
-    FirstArgumentLabelIndex = 3,
+    ModuleSelectorIndex = 1,
+    LParenIndex = 2,
+    RParenIndex = 3,
+    FirstArgumentLabelIndex = 4,
   };
 
   /// Retrieve a pointer to either the only source location that was
   /// stored or to the array of source locations that was stored.
   SourceLoc const * getSourceLocs() const {
-    if (NumArgumentLabels == 0) 
+    if (NumArgumentLabels == 0 && !HasModuleSelectorLoc)
       return reinterpret_cast<SourceLoc const *>(&LocationInfo);
 
     return reinterpret_cast<SourceLoc const *>(LocationInfo);
   }
 
-  DeclNameLoc(const void *LocationInfo, unsigned NumArgumentLabels)
-      : LocationInfo(LocationInfo), NumArgumentLabels(NumArgumentLabels) {}
+  DeclNameLoc(const void *LocationInfo, unsigned NumArgumentLabels,
+              bool HasModuleSelectorLoc)
+      : LocationInfo(LocationInfo), NumArgumentLabels(NumArgumentLabels),
+        HasModuleSelectorLoc(HasModuleSelectorLoc) {}
 
 public:
   /// Create an invalid declaration name location.
-  DeclNameLoc() : DeclNameLoc(nullptr, 0) {}
+  DeclNameLoc() : DeclNameLoc(nullptr, 0, false) {}
 
   /// Create declaration name location information for a base name.
   explicit DeclNameLoc(SourceLoc baseNameLoc)
-      : DeclNameLoc(baseNameLoc.getOpaquePointerValue(), 0) {}
+      : DeclNameLoc(baseNameLoc.getOpaquePointerValue(), 0, false) {}
 
   explicit DeclNameLoc(ASTContext &ctx, SourceLoc moduleSelectorLoc,
                        SourceLoc baseNameLoc)
-    : DeclNameLoc(baseNameLoc) { }
+    : DeclNameLoc(ctx, moduleSelectorLoc, baseNameLoc,
+                  SourceLoc(), {}, SourceLoc()) { }
 
   /// Create declaration name location information for a compound
   /// name.
   DeclNameLoc(ASTContext &ctx, SourceLoc baseNameLoc,
               SourceLoc lParenLoc,
               ArrayRef<SourceLoc> argumentLabelLocs,
-              SourceLoc rParenLoc);
+              SourceLoc rParenLoc)
+    : DeclNameLoc(ctx, SourceLoc(), baseNameLoc,
+                  lParenLoc, argumentLabelLocs, rParenLoc) { }
 
   DeclNameLoc(ASTContext &ctx, SourceLoc moduleSelectorLoc,
               SourceLoc baseNameLoc,
               SourceLoc lParenLoc,
               ArrayRef<SourceLoc> argumentLabelLocs,
-              SourceLoc rParenLoc)
-    : DeclNameLoc(ctx, baseNameLoc, lParenLoc, argumentLabelLocs, rParenLoc) { }
+              SourceLoc rParenLoc);
 
   /// Whether the location information is valid.
   bool isValid() const { return getBaseNameLoc().isValid(); }
@@ -125,11 +133,12 @@ class DeclNameLoc {
   }
 
   SourceLoc getModuleSelectorLoc() const {
-    return SourceLoc();
+    if (!HasModuleSelectorLoc) return SourceLoc();
+    return getSourceLocs()[ModuleSelectorIndex];
   }
 
   SourceLoc getStartLoc() const {
-    return getBaseNameLoc();
+    return HasModuleSelectorLoc ? getModuleSelectorLoc() : getBaseNameLoc();
   }
 
   SourceLoc getEndLoc() const {
@@ -138,9 +147,7 @@ class DeclNameLoc {
 
   /// Retrieve the complete source range for this declaration name.
   SourceRange getSourceRange() const {
-    if (NumArgumentLabels == 0) return getBaseNameLoc();
-
-    return SourceRange(getBaseNameLoc(), getRParenLoc());
+    return SourceRange(getStartLoc(), getEndLoc());
   }
 };
 

include/swift/AST/DiagnosticsParse.def

@@ -93,6 +93,21 @@ ERROR(forbidden_interpolated_string,none,
 ERROR(forbidden_extended_escaping_string,none,
       "%0 cannot be an extended escaping string literal", (StringRef))
 
+ERROR(expected_identifier_in_module_selector,none,
+      "expected identifier in module selector", ())
+ERROR(module_selector_not_allowed,none,
+      "%select{%error|%error|name in %1 declaration|captured variable name|"
+      "parameter name|generic parameter name|argument label|SPI group|"
+      "Objective-C name|name of sibling declaration|precedence group name|"
+      "attribute parameter value|%error}0 cannot be qualified with a module "
+      "selector",
+      (uint8_t, StringRef))
+NOTE(fixit_remove_module_selector,none,
+     "remove module selector from this name", ())
+NOTE(fixit_capture_with_explicit_name,none,
+     "explicitly capture into a variable named '%0'",
+     (StringRef))
+
 //------------------------------------------------------------------------------
 // MARK: Lexer diagnostics
 //------------------------------------------------------------------------------
@@ -2183,5 +2198,9 @@ ERROR(nonisolated_nonsending_expected_rparen,PointsToFirstBadToken,
 ERROR(nonisolated_nonsending_repeated,none,
       "parameter may have at most one 'nonisolated(nonsending)' specifier", ())
 
+ERROR(impossible_parse,none,
+      "parser entered impossible state; please file a bug report with this "
+      "source file", ())
+
 #define UNDEFINE_DIAGNOSTIC_MACROS
 #include "DefineDiagnosticMacros.h"

include/swift/AST/DiagnosticsSema.def

@@ -1159,6 +1159,16 @@ ERROR(cannot_find_type_in_cast_expression,none,
       "type-casting operator expects a type on its right-hand side (got: %kind0)", (const ValueDecl *))
 ERROR(cannot_find_type_in_scope_did_you_mean,none,
       "cannot find type %0 in scope; did you mean to use '%1'?", (DeclNameRef, StringRef))
+ERROR(type_not_in_module,none,
+      "type %0 is not imported through module %1", (DeclName, Identifier))
+ERROR(decl_not_in_module,none,
+      "declaration %0 is not imported through module %1", (DeclName, Identifier))
+NOTE(note_change_module_selector,none,
+     "did you mean module %0?", (Identifier))
+NOTE(note_remove_module_selector,none,
+     "did you mean the local declaration?", ())
+NOTE(note_add_explicit_self_with_module_selector,none,
+     "did you mean the member of 'self'?", ())
 NOTE(note_typo_candidate_implicit_member,none,
      "did you mean the implicitly-synthesized %kindbase0?", (const ValueDecl *))
 NOTE(note_remapped_type,none,