Compute instead of store trailing angle bracket location.

Author: David Ungar

include/swift/AST/Expr.h

@@ -4666,19 +4666,16 @@ class UnresolvedPatternExpr : public Expr {
 class EditorPlaceholderExpr : public Expr {
   Identifier Placeholder;
   SourceLoc Loc;
-  SourceLoc TrailingAngleBracketLoc;
   TypeLoc PlaceholderTy;
   TypeRepr *ExpansionTyR;
   Expr *SemanticExpr;
 
 public:
   EditorPlaceholderExpr(Identifier Placeholder, SourceLoc Loc,
-                        SourceLoc TrailingAngleBracketLoc,
                         TypeLoc PlaceholderTy,
                         TypeRepr *ExpansionTyR)
     : Expr(ExprKind::EditorPlaceholder, /*Implicit=*/false),
       Placeholder(Placeholder), Loc(Loc),
-      TrailingAngleBracketLoc(TrailingAngleBracketLoc),
       PlaceholderTy(PlaceholderTy),
       ExpansionTyR(ExpansionTyR),
       SemanticExpr(nullptr) {
@@ -4689,7 +4686,7 @@ class EditorPlaceholderExpr : public Expr {
   TypeLoc &getTypeLoc() { return PlaceholderTy; }
   TypeLoc getTypeLoc() const { return PlaceholderTy; }
   SourceLoc getTrailingAngleBracketLoc() const {
-    return TrailingAngleBracketLoc;
+    return Loc.getAdvancedLoc(Placeholder.getLength() - 1);
   }
 
   /// The TypeRepr to be considered for placeholder expansion.

lib/Parse/ParseExpr.cpp

@@ -2385,7 +2385,6 @@ Expr *Parser::parseExprEditorPlaceholder(Token PlaceholderTok,
   parseTypeForPlaceholder(TyLoc, ExpansionTyR);
   return new (Context) EditorPlaceholderExpr(PlaceholderId,
                                              PlaceholderTok.getLoc(),
-                                             PlaceholderTok.getRange().getEnd(),
                                              TyLoc, ExpansionTyR);
 }
 

test/Parse/source_locs.swift

@@ -7,5 +7,5 @@ func string_interpolation() {
 
 // RUN: not %target-swift-frontend -dump-ast %s | %FileCheck %s
 // CHECK: (interpolated_string_literal_expr {{.*}} trailing_quote_loc=SOURCE_DIR{{/|\\}}test{{/|\\}}Parse{{/|\\}}source_locs.swift:4:12 {{.*}}
-// CHECK: (editor_placeholder_expr type='()' {{.*}} trailing_angle_bracket_loc=SOURCE_DIR{{/|\\}}test{{/|\\}}Parse{{/|\\}}source_locs.swift:5:10
+// CHECK: (editor_placeholder_expr type='()' {{.*}} trailing_angle_bracket_loc=SOURCE_DIR{{/|\\}}test{{/|\\}}Parse{{/|\\}}source_locs.swift:5:9