Merge pull request #66276 from CrazyFanFan/kongkaikai/fix_66206

[Diagnostics] Fix #66206: Remove the whitespace on the left-hand side of "??"

Author: LucianoPAlmeida

lib/Sema/MiscDiagnostics.cpp

@@ -1405,10 +1405,14 @@ static void diagSyntacticUseRestrictions(const Expr *E, const DeclContext *DC,
       Expr *subExpr = nullptr;
       if (calleeName == "??" &&
           (subExpr = isImplicitPromotionToOptional(lhs))) {
-        Ctx.Diags.diagnose(DRE->getLoc(), diag::use_of_qq_on_non_optional_value,
-                           subExpr->getType())
-          .highlight(lhs->getSourceRange())
-          .fixItRemove(SourceRange(DRE->getLoc(), rhs->getEndLoc()));
+
+        Ctx.Diags
+            .diagnose(DRE->getLoc(), diag::use_of_qq_on_non_optional_value,
+                      subExpr->getType())
+            .highlight(lhs->getSourceRange())
+            .fixItRemoveChars(
+                Lexer::getLocForEndOfToken(Ctx.SourceMgr, lhs->getEndLoc()),
+                Lexer::getLocForEndOfToken(Ctx.SourceMgr, rhs->getEndLoc()));
         return;
       }
 

test/Constraints/diagnostics.swift

@@ -1557,3 +1557,26 @@ do {
     result.append(value) // expected-error {{argument type 'NonHashable' does not conform to expected type 'Hashable'}}
   }
 }
+
+// https://github.com/apple/swift/issues/66206
+func testNilCoalescingOperatorRemoveFix() {
+  let _ = "" ?? "" // expected-warning {{left side of nil coalescing operator '??' has non-optional type 'String', so the right side is never used}} {{13-19=}}
+  let _ = ""     ?? "" // expected-warning {{left side of nil coalescing operator '??' has non-optional type 'String', so the right side is never used}} {{13-23=}}
+  let _ = "" /* This is a comment */ ?? "" // expected-warning {{left side of nil coalescing operator '??' has non-optional type 'String', so the right side is never used}} {{13-43=}}
+
+  let _ = "" // This is a comment
+    ?? "" // expected-warning {{left side of nil coalescing operator '??' has non-optional type 'String', so the right side is never used}} {{1567:13-1568:10=}}
+
+  let _ = "" // This is a comment
+    /*
+     * The blank line below is part of the test case, do not delete it
+     */
+
+    ?? "" // expected-warning {{left side of nil coalescing operator '??' has non-optional type 'String', so the right side is never used}} {{1570:13-1575:10=}}
+
+  if ("" ?? // This is a comment // expected-warning {{left side of nil coalescing operator '??' has non-optional type 'String', so the right side is never used}} {{1577:9-1578:9=}}
+      "").isEmpty {}
+
+  if ("" // This is a comment
+      ?? "").isEmpty {} // expected-warning {{left side of nil coalescing operator '??' has non-optional type 'String', so the right side is never used}} {{1580:9-1581:12=}}
+}

test/expr/expressions.swift

@@ -801,7 +801,7 @@ func testNilCoalescePrecedence(cond: Bool, a: Int?, r: ClosedRange<Int>?) {
   // <rdar://problem/27457457> [Type checker] Diagnose unsavory optional injections
   // Accidental optional injection for ??.
   let i = 42
-  _ = i ?? 17 // expected-warning {{left side of nil coalescing operator '??' has non-optional type 'Int', so the right side is never used}} {{9-15=}}
+  _ = i ?? 17 // expected-warning {{left side of nil coalescing operator '??' has non-optional type 'Int', so the right side is never used}} {{8-14=}}
 }
 
 // <rdar://problem/19772570> Parsing of as and ?? regressed