[Diagnostics] Restricting member subscript tailored diagnostics to literal within bounds of tuple elements

Author: LucianoPAlmeida

lib/Sema/CSDiagnostics.cpp

@@ -3450,16 +3450,28 @@ bool MissingMemberFailure::diagnoseForSubscriptMemberWithTupleBase() const {
   if (SE->getNumArguments() == 1) {
     auto *literal =
         dyn_cast<IntegerLiteralExpr>(index->getSemanticsProvidingExpr());
-    if (literal && !literal->isNegative()) {
-      llvm::SmallString<4> dotAccess;
-      llvm::raw_svector_ostream OS(dotAccess);
-      OS << "." << literal->getDigitsText();
 
-      emitDiagnostic(
-          diag::could_not_find_subscript_member_tuple_did_you_mean_use_dot,
-          baseType, literal->getDigitsText())
-          .fixItReplace(index->getSourceRange(), OS.str());
-      return true;
+    llvm::Regex NumericRegex("^[0-9]+$");
+    // Literal expressions may have other types of representations e.g. 0x01,
+    // 0b01. So let's make sure to only suggest this tailored literal fix-it for
+    // number only literals.
+    if (literal && NumericRegex.match(literal->getDigitsText())) {
+      unsigned int literalValue = 0;
+      literal->getDigitsText().getAsInteger(/*Radix*/ 0, literalValue);
+
+      // Verify if the literal value is within the bounds of tuple elements.
+      if (!literal->isNegative() &&
+          literalValue < tupleType->getNumElements()) {
+        llvm::SmallString<4> dotAccess;
+        llvm::raw_svector_ostream OS(dotAccess);
+        OS << "." << literalValue;
+
+        emitDiagnostic(
+            diag::could_not_find_subscript_member_tuple_did_you_mean_use_dot,
+            baseType, literal->getDigitsText())
+            .fixItReplace(index->getSourceRange(), OS.str());
+        return true;
+      }
     }
   }
 

test/Constraints/members.swift

@@ -675,23 +675,42 @@ let _ : [Int: Any] = [1 : .e] // expected-error {{type 'Any' has no member 'e'}}
 let _ : (Int, Any) = (1, .e) // expected-error {{type 'Any' has no member 'e'}}
 _ = (1, .e) // expected-error {{cannot infer contextual base in reference to member 'e'}}
 
+// SR-13359
+
 // SR-13359
 typealias Pair = (Int, Int)
 func testSR13359(_ pair: (Int, Int), _ alias: Pair, _ void: Void, labeled: (a: Int, b: Int)) {
   _ = pair[0] // expected-error {{cannot access element using subscript for tuple type '(Int, Int)'; did you mean to use '.0'?}} {{11-14=.0}}
+  _ = pair[1] // expected-error {{cannot access element using subscript for tuple type '(Int, Int)'; did you mean to use '.1'?}} {{11-14=.1}}
+  _ = pair[2] // expected-error {{cannot access element using subscript for tuple type '(Int, Int)'; use '.' notation instead}} {{none}}
+  _ = pair[100] // expected-error {{cannot access element using subscript for tuple type '(Int, Int)'; use '.' notation instead}} {{none}}
   _ = pair["strting"] // expected-error {{cannot access element using subscript for tuple type '(Int, Int)'; use '.' notation instead}} {{none}}
   _ = pair[-1] // expected-error {{cannot access element using subscript for tuple type '(Int, Int)'; use '.' notation instead}} {{none}}
   _ = pair[1, 1] // expected-error {{cannot access element using subscript for tuple type '(Int, Int)'; use '.' notation instead}} {{none}}
   _ = void[0] // expected-error {{value of type 'Void' has no subscripts}}
+  // Other representations of literals
+  _ = pair[0x00] // expected-error {{cannot access element using subscript for tuple type '(Int, Int)'; use '.' notation instead}} {{none}}
+  _ = pair[0b00] // expected-error {{cannot access element using subscript for tuple type '(Int, Int)'; use '.' notation instead}} {{none}}
 
   _ = alias[0] // expected-error {{cannot access element using subscript for tuple type 'Pair' (aka '(Int, Int)'); did you mean to use '.0'?}} {{12-15=.0}}
+  _ = alias[1] // expected-error {{cannot access element using subscript for tuple type 'Pair' (aka '(Int, Int)'); did you mean to use '.1'?}} {{12-15=.1}}
+  _ = alias[2] // expected-error {{cannot access element using subscript for tuple type 'Pair' (aka '(Int, Int)'); use '.' notation instead}} {{none}}
+  _ = alias[100] // expected-error {{cannot access element using subscript for tuple type 'Pair' (aka '(Int, Int)'); use '.' notation instead}} {{none}}
   _ = alias["strting"] // expected-error {{cannot access element using subscript for tuple type 'Pair' (aka '(Int, Int)'); use '.' notation instead}} {{none}}
   _ = alias[-1] // expected-error {{cannot access element using subscript for tuple type 'Pair' (aka '(Int, Int)'); use '.' notation instead}} {{none}}
   _ = alias[1, 1] // expected-error {{cannot access element using subscript for tuple type 'Pair' (aka '(Int, Int)'); use '.' notation instead}} {{none}}
+  _ = alias[0x00] // expected-error {{cannot access element using subscript for tuple type 'Pair' (aka '(Int, Int)'); use '.' notation instead}} {{none}}
+  _ = alias[0b00] // expected-error {{cannot access element using subscript for tuple type 'Pair' (aka '(Int, Int)'); use '.' notation instead}} {{none}}
 
   // Labeled tuple base
   _ = labeled[0] // expected-error {{cannot access element using subscript for tuple type '(a: Int, b: Int)'; did you mean to use '.0'?}} {{14-17=.0}}
+  _ = labeled[1] // expected-error {{cannot access element using subscript for tuple type '(a: Int, b: Int)'; did you mean to use '.1'?}} {{14-17=.1}}
+  _ = labeled[2] // expected-error {{cannot access element using subscript for tuple type '(a: Int, b: Int)'; use '.' notation instead}} {{none}}
+  _ = labeled[100] // expected-error {{cannot access element using subscript for tuple type '(a: Int, b: Int)'; use '.' notation instead}} {{none}}
   _ = labeled["strting"] // expected-error {{cannot access element using subscript for tuple type '(a: Int, b: Int)'; use '.' notation instead}} {{none}}
   _ = labeled[-1] // expected-error {{cannot access element using subscript for tuple type '(a: Int, b: Int)'; use '.' notation instead}} {{none}}
   _ = labeled[1, 1] // expected-error {{cannot access element using subscript for tuple type '(a: Int, b: Int)'; use '.' notation instead}} {{none}}
+  _ = labeled[0x00] // expected-error {{cannot access element using subscript for tuple type '(a: Int, b: Int)'; use '.' notation instead}} {{none}}
+  _ = labeled[0b00] // expected-error {{cannot access element using subscript for tuple type '(a: Int, b: Int)'; use '.' notation instead}} {{none}}
+
 }