Overhaul the handling of return locations for auto-generated code.

- change SILGenFunction to use Cleanup and Implicit return locations for
  auto-generated cleanups/returns where sensible.
- Fix a bug in where ConstructorDecl that would return the wrong
  source range.
- Move the expected locations of some errors to the end of the function
  where they should belong.

Fixes <rdar://problem/15609768> Line tables for classes that don't have
init but just initialize ivars are odd

Swift SVN r11086

Author: adrian-prantl

include/swift/SIL/SILInstruction.h

@@ -104,7 +104,7 @@ class SILInstruction : public ValueBase,public llvm::ilist_node<SILInstruction>{
 
   SILLocation getLoc() const { return Loc; }
   SILDebugScope *getDebugScope() const { return DebugScope; }
-  void setDebugScope(SILDebugScope *DS)  { DebugScope = DS; }
+  SILInstruction *setDebugScope(SILDebugScope *DS)  { DebugScope = DS; return this; }
 
   /// removeFromParent - This method unlinks 'self' from the containing basic
   /// block, but does not delete it.

include/swift/SIL/SILLocation.h

@@ -131,14 +131,6 @@ class SILLocation {
     return cast<T>(Node.get<typename base_type<T>::type*>());
   }
 
-  /// \brief Check if the corresponding source code location definitely points
-  ///  to the start of the AST node.
-  bool alwaysPointsToStart() const { return KindData & (1 << PointsToStartBit);}
-
-  /// \brief Check if the corresponding source code location definitely points
-  ///  to the end of the AST node.
-  bool alwaysPointsToEnd() const { return KindData & (1 << PointsToEndBit); }
-
   // SILLocation constructors.
   SILLocation(LocationKind K) : KindData(K) {}
   SILLocation(Stmt *S, LocationKind K) : ASTNode(S), KindData(K) {}
@@ -208,6 +200,14 @@ class SILLocation {
 
   bool hasASTLocation() const { return !ASTNode.isNull(); }
 
+  /// \brief Check if the corresponding source code location definitely points
+  ///  to the start of the AST node.
+  bool alwaysPointsToStart() const { return KindData & (1 << PointsToStartBit);}
+
+  /// \brief Check if the corresponding source code location definitely points
+  ///  to the end of the AST node.
+  bool alwaysPointsToEnd() const { return KindData & (1 << PointsToEndBit); }
+
   LocationKind getKind() const { return (LocationKind)(KindData & BaseMask); }
 
   template <typename T>
@@ -340,21 +340,20 @@ class ImplicitReturnLocation : public SILLocation {
 public:
 
   ImplicitReturnLocation(AbstractClosureExpr *E)
-    : SILLocation(E, ImplicitReturnKind) { pointToEnd(); }
+    : SILLocation(E, ImplicitReturnKind) { }
 
   ImplicitReturnLocation(AbstractFunctionDecl *AFD)
-    : SILLocation(AFD, ImplicitReturnKind) { pointToEnd(); }
+    : SILLocation(AFD, ImplicitReturnKind) { }
 
   /// \brief Construct from a RegularLocation; preserve all special bits.
   ///
   /// Note, this can construct an implicit return for an arbitrary expression
   /// (specifically, in case of auto-generated bodies).
   static SILLocation getImplicitReturnLoc(SILLocation L) {
     assert(L.isASTNode<Expr>() ||
-           L.isASTNode<AbstractFunctionDecl>() ||
+           L.isASTNode<ValueDecl>() ||
            (L.isNull() && L.isInTopLevel()));
     L.setKind(ImplicitReturnKind);
-    L.pointToEnd();
     return L;
   }
 
@@ -446,7 +445,7 @@ class MandatoryInlinedLocation : public SILLocation {
 /// \brief Used on the instruction performing auto-generated cleanup such as
 /// deallocs, destructor calls.
 ///
-/// The cleanups are performed after completing the evaluztion of the AST Node
+/// The cleanups are performed after completing the evaluation of the AST Node
 /// wrapped inside the SILLocation. This location wraps the statement
 /// representing the enclosing scope, for example, FuncDecl, ParenExpr. The
 /// scope's end location points to the SourceLoc that shows when the operation

lib/AST/Decl.cpp

@@ -1525,9 +1525,9 @@ SourceRange ConstructorDecl::getSourceRange() const {
     const DeclContext *DC = getDeclContext();
     switch (DC->getContextKind()) {
     case DeclContextKind::ExtensionDecl:
-      return cast<ExtensionDecl>(DC)->getLoc();
+      return cast<ExtensionDecl>(DC)->getSourceRange();
     case DeclContextKind::NominalTypeDecl:
-      return cast<NominalTypeDecl>(DC)->getLoc();
+      return cast<NominalTypeDecl>(DC)->getSourceRange();
     default:
       if (isInvalid())
         return getConstructorLoc();

lib/IRGen/IRGenDebugInfo.cpp

@@ -189,6 +189,7 @@ static FullLocation getLocation(SourceManager &SM, Optional<SILLocation> OptLoc)
     return {};
 
   SILLocation Loc = OptLoc.getValue();
+  bool UseEnd = Loc.alwaysPointsToEnd();
 
   if (Loc.isNull()) return {};
   if (Expr *E = Loc.getAsASTNode<Expr>()) {
@@ -198,29 +199,29 @@ static FullLocation getLocation(SourceManager &SM, Optional<SILLocation> OptLoc)
     // on how we decide to resolve rdar://problem/14627460, we may
     // want to use the regular getLoc instead and rather use the
     // column info.
-    auto ELoc = getLoc(SM, E);
+    auto ELoc = getLoc(SM, E, UseEnd);
     if (isa<AutoClosureExpr>(E))
       return {{}, ELoc};
     return {ELoc, ELoc};
   }
   if (Pattern* P = Loc.getAsASTNode<Pattern>()) {
-    auto PLoc = getLoc(SM, P);
+    auto PLoc = getLoc(SM, P, UseEnd);
     return {PLoc, PLoc};
   }
   if (Stmt* S = Loc.getAsASTNode<Stmt>()) {
-    auto SLoc = getLoc(SM, S);
+    auto SLoc = getLoc(SM, S, UseEnd);
     return {SLoc, SLoc};
   }
 
   if (Decl* D = Loc.getAsASTNode<Decl>()) {
-    auto DLoc = getLoc(SM, D);
+    auto DLoc = getLoc(SM, D, UseEnd);
     auto LinetableLoc = DLoc;
     if (Loc.isInPrologue())
       LinetableLoc = {};
 
-    // FIXME: It may or may not be better to fix this in SILLocation.
-    // If this is an implicit return, we want the end of the
-    // AbstractFunctionDecl's body.
+    // For return and cleanup code SILLocation points to the start,
+    // because this is where we want diagnostics to appear. For the
+    // line table, we want them to point to the end of the Decl.
     else if (Loc.getKind() == SILLocation::ImplicitReturnKind ||
              Loc.getKind() == SILLocation::CleanupKind)
       LinetableLoc = getLoc(SM, D, true);