SILLocation: remove unused flag bits.

PointsToStartBit: was never set.
IsInTopLevel: was never checked (except for SIL printing)

Author: eeckstein

include/swift/SIL/SILLocation.h

@@ -153,21 +153,12 @@ class SILLocation {
     /// code block.
     AutoGeneratedBit = 5,
 
-    /// Used to redefine the default source location used to
-    /// represent this SILLocation. For example, when the host instruction
-    /// is known to correspond to the beginning or the end of the source
-    /// range of the ASTNode.
-    PointsToStartBit = 6,
-    PointsToEndBit = 7,
-
-    /// Used to notify that this instruction belongs to the top-
-    /// level (module) scope.
-    ///
-    /// FIXME: If Module becomes a Decl, this could be removed.
-    IsInTopLevel = 8,
+    /// The location correspond to the end (instead of the beginning) of the
+    /// source range of the ASTNode.
+    PointsToEndBit = 6,
 
     /// Marks this instruction as belonging to the function prologue.
-    IsInPrologue = 9
+    IsInPrologue = 7
   };
 
   template <typename T>
@@ -314,21 +305,10 @@ class SILLocation {
     return decodeDebugLoc(SM).Line == 0;
   }
 
-  /// Changes the default source location position to point to start of
-  /// the AST node.
-  void pointToStart() { KindData |= (1 << PointsToStartBit); }
-
   /// Changes the default source location position to point to the end of
   /// the AST node.
   void pointToEnd() { KindData |= (1 << PointsToEndBit); }
 
-  /// Mark this location as the location corresponding to the top-level
-  /// (module-level) code.
-  void markAsInTopLevel() { KindData |= (1 << IsInTopLevel); }
-
-  /// Check is this location is associated with the top level/module.
-  bool isInTopLevel() const { return KindData & (1 << IsInTopLevel); }
-
   /// Mark this location as being part of the function
   /// prologue, which means that it deals with setting up the stack
   /// frame. The first breakpoint location in a function is at the end
@@ -360,10 +340,6 @@ class SILLocation {
     setStorageKind(DebugInfoKind);
   }
 
-  /// Check if the corresponding source code location definitely points
-  ///  to the start of the AST node.
-  bool alwaysPointsToStart() const { return KindData & (1 << PointsToStartBit);}
-
   /// Check if the corresponding source code location definitely points
   ///  to the end of the AST node.
   bool alwaysPointsToEnd() const { return KindData & (1 << PointsToEndBit); }
@@ -507,11 +483,7 @@ class RegularLocation : public SILLocation {
   RegularLocation(DebugLoc L) : SILLocation(L, RegularKind) {}
 
   /// Returns a location representing the module.
-  static RegularLocation getModuleLocation() {
-    RegularLocation Loc;
-    Loc.markAsInTopLevel();
-    return Loc;
-  }
+  static RegularLocation getModuleLocation() { return RegularLocation(); }
 
   /// If the current value is of the specified AST unit type T,
   /// return it, otherwise return null.
@@ -717,9 +689,7 @@ class CleanupLocation : public SILLocation {
 
   /// Returns a location representing a cleanup on the module level.
   static CleanupLocation getModuleCleanupLocation() {
-    CleanupLocation Loc;
-    Loc.markAsInTopLevel();
-    return Loc;
+    return CleanupLocation();
   }
 
 private:

lib/SIL/IR/SILLocation.cpp

@@ -15,6 +15,7 @@
 #include "swift/AST/Expr.h"
 #include "swift/AST/Pattern.h"
 #include "swift/AST/Stmt.h"
+#include "swift/AST/Module.h"
 #include "swift/Basic/SourceManager.h"
 #include "llvm/Support/raw_ostream.h"
 
@@ -40,8 +41,7 @@ SourceLoc SILLocation::getSourceLoc(ASTNodeTy N) const {
   if (N.isNull())
     return SourceLoc();
 
-  if (alwaysPointsToStart() ||
-      alwaysPointsToEnd() ||
+  if (alwaysPointsToEnd() ||
       is<CleanupLocation>() ||
       is<ImplicitReturnLocation>())
     return getEndSourceLoc(N);
@@ -158,9 +158,7 @@ void SILLocation::dump(const SourceManager &SM) const {
   print(llvm::errs(), SM);
 
   if (isAutoGenerated())     llvm::errs() << ":auto";
-  if (alwaysPointsToStart()) llvm::errs() << ":start";
   if (alwaysPointsToEnd())   llvm::errs() << ":end";
-  if (isInTopLevel())        llvm::errs() << ":toplevel";
   if (isInPrologue())        llvm::errs() << ":prologue";
   if (isSILFile())           llvm::errs() << ":sil";
   if (hasDebugLoc()) {
@@ -189,9 +187,6 @@ InlinedLocation InlinedLocation::getInlinedLocation(SILLocation L) {
   if (L.isSILFile())
     return InlinedLocation(L.Loc.SILFileLoc, L.getSpecialFlags());
 
-  if (L.isInTopLevel())
-    return InlinedLocation::getModuleLocation(L.getSpecialFlags());
-
   if (L.isAutoGenerated()) {
     InlinedLocation IL;
     IL.markAutoGenerated();
@@ -214,9 +209,6 @@ MandatoryInlinedLocation::getMandatoryInlinedLocation(SILLocation L) {
   if (L.isSILFile())
     return MandatoryInlinedLocation(L.Loc.SILFileLoc, L.getSpecialFlags());
 
-  if (L.isInTopLevel())
-    return MandatoryInlinedLocation::getModuleLocation(L.getSpecialFlags());
-
   if (L.isDebugInfoLoc())
     return MandatoryInlinedLocation(L.getDebugInfoLoc(), L.getSpecialFlags());
 
@@ -268,7 +260,7 @@ SILLocation ImplicitReturnLocation::getImplicitReturnLoc(SILLocation L) {
   assert(L.isASTNode<Expr>() ||
          L.isASTNode<ValueDecl>() ||
          L.isASTNode<PatternBindingDecl>() ||
-         (L.isNull() && L.isInTopLevel()));
+         L.isNull());
   L.setLocationKind(ImplicitReturnKind);
   return L;
 }

lib/SIL/IR/SILPrinter.cpp

@@ -921,9 +921,7 @@ class SILPrinter : public SILInstructionVisitor<SILPrinter> {
         PrintState.OS.PadToColumn(50);
         *this << "//";
       }
-      if (L.isInTopLevel())
-        *this << " top_level";
-      else if (L.isAutoGenerated())
+      if (L.isAutoGenerated())
         *this << " auto_gen";
       else
         *this << " no_loc";

test/SILGen/sil_locations_top_level.swift

@@ -16,8 +16,8 @@ class TopLevelObjectTyWithoutDestructor {
 var topLevelObject2:TopLevelObjectTyWithoutDestructor
 
 // CHECK-LABEL: sil [ossa] @main
-// CHECK: integer_literal ${{.*}}, 0, {{.*}} top_level
-// CHECK: return    {{.*}} top_level
+// CHECK: integer_literal ${{.*}}, 0, {{.*}} auto_gen
+// CHECK: return    {{.*}} auto_gen
 
 // Check allocating initializer
 // CHECK-LABEL: sil_locations_top_level.TopLevelObjectTy.__allocating_init