[MiscDiagnostics] Update diagnostics for IUO to Any coercion

include/swift/AST/DiagnosticsSema.def

@@ -3012,6 +3012,15 @@ WARNING(optional_pattern_match_promotion,none,
         (Type, Type))
 WARNING(optional_to_any_coercion,none,
         "expression implicitly coerced from %0 to %1", (Type, Type))
+WARNING(iuo_to_any_coercion,none,
+        "coercion of implicitly unwrappable value of type %0 to %1 does not "
+        "unwrap optional", (Type, Type))
+NOTE(iuo_to_any_coercion_note,none,
+     "implicitly unwrapped %0 %1 declared here",
+     (DescriptiveDeclKind, DeclName))
+NOTE(iuo_to_any_coercion_note_func_result,none,
+     "%0 %1 with implicitly unwrapped result type is declared here",
+     (DescriptiveDeclKind, DeclName))
 NOTE(default_optional_to_any,none,
      "provide a default value to avoid this warning", ())
 NOTE(force_optional_to_any,none,

lib/Sema/MiscDiagnostics.cpp

@@ -3395,36 +3395,39 @@ static void diagnoseUnintendedOptionalBehavior(TypeChecker &TC, const Expr *E,
     }
 
     static bool hasImplicitlyUnwrappedResult(Expr *E) {
-      auto getDeclForExpr = [&](Expr *E) -> ValueDecl * {
-        if (auto *call = dyn_cast<CallExpr>(E))
-          E = call->getDirectCallee();
+      auto *decl = getDeclForImplicitlyUnwrappedExpr(E);
 
-        if (auto *subscript = dyn_cast<SubscriptExpr>(E)) {
-          if (subscript->hasDecl())
-            return subscript->getDecl().getDecl();
-
-          return nullptr;
-        }
-
-        if (auto *memberRef = dyn_cast<MemberRefExpr>(E))
-          return memberRef->getMember().getDecl();
-        if (auto *declRef = dyn_cast<DeclRefExpr>(E))
-          return declRef->getDecl();
-        if (auto *apply = dyn_cast<ApplyExpr>(E))
-          return apply->getCalledValue();
+      return decl
+        && decl->getAttrs().hasAttribute<ImplicitlyUnwrappedOptionalAttr>();
+    }
 
-        return nullptr;
-      };
+    static ValueDecl *getDeclForImplicitlyUnwrappedExpr(Expr *E) {
+      E = E->getValueProvidingExpr();
 
       // Look through implicit conversions like loads, derived-to-base
       // conversion, etc.
-      if (auto *ICE = dyn_cast<ImplicitConversionExpr>(E))
+      if (auto *ICE = dyn_cast<ImplicitConversionExpr>(E)) {
         E = ICE->getSubExpr();
+      }
 
-      auto *decl = getDeclForExpr(E);
+      if (auto *subscript = dyn_cast<SubscriptExpr>(E)) {
+        if (subscript->hasDecl())
+          return subscript->getDecl().getDecl();
+        return nullptr;
+      }
 
-      return decl
-        && decl->getAttrs().hasAttribute<ImplicitlyUnwrappedOptionalAttr>();
+      if (auto *memberRef = dyn_cast<MemberRefExpr>(E))
+        return memberRef->getMember().getDecl();
+
+      if (auto *declRef = dyn_cast<DeclRefExpr>(E))
+        return declRef->getDecl();
+
+      if (auto *apply = dyn_cast<ApplyExpr>(E)) {
+        auto *decl = apply->getCalledValue();
+        if (decl && isa<AbstractFunctionDecl>(decl))
+          return decl;
+      }
+      return nullptr;
     }
 
     void visitErasureExpr(ErasureExpr *E, OptionalToAnyCoercion coercion) {
@@ -3455,15 +3458,32 @@ static void diagnoseUnintendedOptionalBehavior(TypeChecker &TC, const Expr *E,
       size_t optionalityDifference = 0;
       if (!isOptionalToAnyCoercion(srcType, destType, optionalityDifference))
         return;
-
-      TC.diagnose(subExpr->getStartLoc(), diag::optional_to_any_coercion,
-                  /* from */ srcType, /* to */ destType)
-        .highlight(subExpr->getSourceRange());
-
+
+      // If we're implicitly unwrapping from IUO to Any then emit a custom
+      // diagnostic
+      if (hasImplicitlyUnwrappedResult(subExpr)) {
+        if (auto decl = getDeclForImplicitlyUnwrappedExpr(subExpr)) {
+          TC.diagnose(subExpr->getStartLoc(), diag::iuo_to_any_coercion,
+                      /* from */ srcType, /* to */ destType)
+              .highlight(subExpr->getSourceRange());
+
+          auto noteDiag = isa<FuncDecl>(decl)
+                              ? diag::iuo_to_any_coercion_note_func_result
+                              : diag::iuo_to_any_coercion_note;
+
+          TC.diagnose(decl->getLoc(), noteDiag, decl->getDescriptiveKind(),
+                      decl->getFullName());
+        }
+      } else {
+        TC.diagnose(subExpr->getStartLoc(), diag::optional_to_any_coercion,
+                    /* from */ srcType, /* to */ destType)
+            .highlight(subExpr->getSourceRange());
+      }
+
       if (optionalityDifference == 1) {
         TC.diagnose(subExpr->getLoc(), diag::default_optional_to_any)
-          .highlight(subExpr->getSourceRange())
-          .fixItInsertAfter(subExpr->getEndLoc(), " ?? <#default value#>");
+            .highlight(subExpr->getSourceRange())
+            .fixItInsertAfter(subExpr->getEndLoc(), " ?? <#default value#>");
       }
 
       SmallString<4> forceUnwrapString;

test/Sema/diag_unintended_optional_behavior_swift_5.swift

@@ -9,69 +9,69 @@ func takeAny(_ left: Any, _ right: Any) -> Int? {
 func takesOptionalAny(_: Any?, _: Any?) {}
 
 class C {
-  var a: Int!
-  var b: Any?!
-  func returningIUO() -> Int! { return a }
-  func returningAny() -> Any { return a } // expected-warning {{expression implicitly coerced from 'Int?' to 'Any'}}
+  var a: Int! // expected-note 2{{implicitly unwrapped property 'a' declared here}}
+  var b: Any?! // expected-note {{implicitly unwrapped property 'b' declared here}}
+  func returningIUO() -> Int! { return a } // expected-note {{instance method 'returningIUO()' with implicitly unwrapped result type is declared here}}
+  func returningAny() -> Any { return a } // expected-warning {{coercion of implicitly unwrappable value of type 'Int?' to 'Any' does not unwrap optional}}
   // expected-note@-1 {{provide a default value to avoid this warning}}{{40-40= ?? <#default value#>}}
   // expected-note@-2 {{force-unwrap the value to avoid this warning}}{{40-40=!}}
   // expected-note@-3 {{explicitly cast to 'Any' with 'as Any' to silence this warning}}{{40-40= as Any}}
 
-  subscript(i: Int) -> Int! { return 0 }
-  subscript(i: Float) -> Any! { return 0 }
+  subscript(i: Int) -> Int! { return 0 } // expected-note {{implicitly unwrapped subscript 'subscript(_:)' declared here}}
+  subscript(i: Float) -> Any! { return 0 } // expected-note {{implicitly unwrapped subscript 'subscript(_:)' declared here}}
 }
 
 class D {
-  init!() {}
+  init!() {} // expected-note 2{{implicitly unwrapped initializer 'init()' declared here}}
 }
 
-func returningIUO() -> Int! { return 1 }
+func returningIUO() -> Int! { return 1 } // expected-note {{global function 'returningIUO()' with implicitly unwrapped result type is declared here}}
 
-func warnIUOToAnyCoercion(_ a: Int!, _ b: Any?!) {
-  _ = takeAny(a, b) // expected-warning {{expression implicitly coerced from 'Int?' to 'Any'}}
+func warnIUOToAnyCoercion(_ a: Int!, _ b: Any?!) { // expected-note {{implicitly unwrapped parameter 'a' declared here}} // expected-note {{implicitly unwrapped parameter 'b' declared here}}
+  _ = takeAny(a, b) // expected-warning {{coercion of implicitly unwrappable value of type 'Int?' to 'Any' does not unwrap optional}}
   // expected-note@-1 {{provide a default value to avoid this warning}}{{16-16= ?? <#default value#>}}
   // expected-note@-2 {{force-unwrap the value to avoid this warning}}{{16-16=!}}
   // expected-note@-3 {{explicitly cast to 'Any' with 'as Any' to silence this warning}}{{16-16= as Any}}
-  // expected-warning@-4 {{expression implicitly coerced from 'Any??' to 'Any'}}
+  // expected-warning@-4 {{coercion of implicitly unwrappable value of type 'Any??' to 'Any' does not unwrap optional}}
   // expected-note@-5 {{force-unwrap the value to avoid this warning}}{{19-19=!!}}
   // expected-note@-6 {{explicitly cast to 'Any' with 'as Any' to silence this warning}}{{19-19= as Any}}
-  _ = takeAny(returningIUO(), C().returningIUO()) // expected-warning {{expression implicitly coerced from 'Int?' to 'Any'}}
+  _ = takeAny(returningIUO(), C().returningIUO()) // expected-warning {{coercion of implicitly unwrappable value of type 'Int?' to 'Any' does not unwrap optional}}
   // expected-note@-1 {{provide a default value to avoid this warning}}{{29-29= ?? <#default value#>}}
   // expected-note@-2 {{force-unwrap the value to avoid this warning}}{{29-29=!}}
   // expected-note@-3 {{explicitly cast to 'Any' with 'as Any' to silence this warning}}{{29-29= as Any}}
-  // expected-warning@-4 {{expression implicitly coerced from 'Int?' to 'Any'}}
+  // expected-warning@-4 {{coercion of implicitly unwrappable value of type 'Int?' to 'Any' does not unwrap optional}}
   // expected-note@-5 {{provide a default value to avoid this warning}}{{49-49= ?? <#default value#>}}
   // expected-note@-6 {{force-unwrap the value to avoid this warning}}{{49-49=!}}
   // expected-note@-7 {{explicitly cast to 'Any' with 'as Any' to silence this warning}}{{49-49= as Any}}
-  _ = takeAny(C().a, C().b) // expected-warning {{expression implicitly coerced from 'Int?' to 'Any'}}
+  _ = takeAny(C().a, C().b) // expected-warning {{coercion of implicitly unwrappable value of type 'Int?' to 'Any' does not unwrap optional}}
   // expected-note@-1 {{provide a default value to avoid this warning}}{{20-20= ?? <#default value#>}}
   // expected-note@-2 {{force-unwrap the value to avoid this warning}}{{20-20=!}}
   // expected-note@-3 {{explicitly cast to 'Any' with 'as Any' to silence this warning}}{{20-20= as Any}}
-  // expected-warning@-4 {{expression implicitly coerced from 'Any??' to 'Any'}}
+  // expected-warning@-4 {{coercion of implicitly unwrappable value of type 'Any??' to 'Any' does not unwrap optional}}
   // expected-note@-5 {{force-unwrap the value to avoid this warning}}{{27-27=!!}}
   // expected-note@-6 {{explicitly cast to 'Any' with 'as Any' to silence this warning}}{{27-27= as Any}}
-  _ = takeAny(C()[0], C()[1.0]) // expected-warning {{expression implicitly coerced from 'Int?' to 'Any'}}
+  _ = takeAny(C()[0], C()[1.0]) // expected-warning {{coercion of implicitly unwrappable value of type 'Int?' to 'Any' does not unwrap optional}}
   // expected-note@-1 {{provide a default value to avoid this warning}}{{21-21= ?? <#default value#>}}
   // expected-note@-2 {{force-unwrap the value to avoid this warning}}{{21-21=!}}
   // expected-note@-3 {{explicitly cast to 'Any' with 'as Any' to silence this warning}}{{21-21= as Any}}
-  // expected-warning@-4 {{expression implicitly coerced from 'Any?' to 'Any'}}
+  // expected-warning@-4 {{coercion of implicitly unwrappable value of type 'Any?' to 'Any' does not unwrap optional}}
   // expected-note@-5 {{provide a default value to avoid this warning}}{{31-31= ?? <#default value#>}}
   // expected-note@-6 {{force-unwrap the value to avoid this warning}}{{31-31=!}}
   // expected-note@-7 {{explicitly cast to 'Any' with 'as Any' to silence this warning}}{{31-31= as Any}}
-  _ = takeAny(D(), D()) // expected-warning {{expression implicitly coerced from 'D?' to 'Any'}}
+  _ = takeAny(D(), D()) // expected-warning {{coercion of implicitly unwrappable value of type 'D?' to 'Any' does not unwrap optional}}
   // expected-note@-1 {{provide a default value to avoid this warning}}{{18-18= ?? <#default value#>}}
   // expected-note@-2 {{force-unwrap the value to avoid this warning}}{{18-18=!}}
   // expected-note@-3 {{explicitly cast to 'Any' with 'as Any' to silence this warning}}{{18-18= as Any}}
-  // expected-warning@-4 {{expression implicitly coerced from 'D?' to 'Any'}}
+  // expected-warning@-4 {{coercion of implicitly unwrappable value of type 'D?' to 'Any' does not unwrap optional}}
   // expected-note@-5 {{provide a default value to avoid this warning}}{{23-23= ?? <#default value#>}}
   // expected-note@-6 {{force-unwrap the value to avoid this warning}}{{23-23=!}}
   // expected-note@-7 {{explicitly cast to 'Any' with 'as Any' to silence this warning}}{{23-23= as Any}}
 
   _ = takeAny(a as Any, b as Any)
 }
 
-func warnIUOToOptionalAnyCoercion(_ a: Int!, _ b: Any?!, _ c: Int??!, _ d: Any???!) {
-  takesOptionalAny(a, b) // expected-warning {{expression implicitly coerced from 'Any??' to 'Any?'}}
+func warnIUOToOptionalAnyCoercion(_ a: Int!, _ b: Any?!, _ c: Int??!, _ d: Any???!) { // expected-note {{implicitly unwrapped parameter 'b' declared here}} // expected-note {{implicitly unwrapped parameter 'c' declared here}} // expected-note {{implicitly unwrapped parameter 'd' declared here}}
+  takesOptionalAny(a, b) // expected-warning {{coercion of implicitly unwrappable value of type 'Any??' to 'Any?' does not unwrap optional}}
   // expected-note@-1 {{provide a default value to avoid this warning}}{{24-24= ?? <#default value#>}}
   // expected-note@-2 {{force-unwrap the value to avoid this warning}}{{24-24=!}}
   // expected-note@-3 {{explicitly cast to 'Any?' with 'as Any?' to silence this warning}}{{24-24= as Any?}}
@@ -80,10 +80,10 @@ func warnIUOToOptionalAnyCoercion(_ a: Int!, _ b: Any?!, _ c: Int??!, _ d: Any??
   takesOptionalAny(a, b!)
   takesOptionalAny(a, b as Any?)
 
-  takesOptionalAny(c, d) // expected-warning {{expression implicitly coerced from 'Int???' to 'Any?'}}
+  takesOptionalAny(c, d) // expected-warning {{coercion of implicitly unwrappable value of type 'Int???' to 'Any?' does not unwrap optional}}
   // expected-note@-1 {{force-unwrap the value to avoid this warning}}{{21-21=!!}}
   // expected-note@-2 {{explicitly cast to 'Any?' with 'as Any?' to silence this warning}}{{21-21= as Any?}}
-  // expected-warning@-3 {{expression implicitly coerced from 'Any????' to 'Any?'}}
+  // expected-warning@-3 {{coercion of implicitly unwrappable value of type 'Any????' to 'Any?' does not unwrap optional}}
   // expected-note@-4 {{force-unwrap the value to avoid this warning}}{{24-24=!!!}}
   // expected-note@-5 {{explicitly cast to 'Any?' with 'as Any?' to silence this warning}}{{24-24= as Any?}}
 
@@ -93,13 +93,21 @@ func warnIUOToOptionalAnyCoercion(_ a: Int!, _ b: Any?!, _ c: Int??!, _ d: Any??
 
 func takesCollectionOfAny(_ a: [Any], _ d: [String : Any]) {}
 
-func warnCollectionOfIUOToAnyCoercion(_ a: Int!) {
-  takesCollectionOfAny([a], ["test" : a]) // expected-warning {{expression implicitly coerced from 'Int?' to 'Any'}}
+func warnCollectionOfIUOToAnyCoercion(_ a: Int!) { // expected-note 2{{implicitly unwrapped parameter 'a' declared here}}
+  takesCollectionOfAny([a], ["test" : a]) // expected-warning {{coercion of implicitly unwrappable value of type 'Int?' to 'Any' does not unwrap optional}}
   // expected-note@-1 {{provide a default value to avoid this warning}}{{26-26= ?? <#default value#>}}
   // expected-note@-2 {{force-unwrap the value to avoid this warning}}{{26-26=!}}
   // expected-note@-3 {{explicitly cast to 'Any' with 'as Any' to silence this warning}}{{26-26= as Any}}
-  // expected-warning@-4 {{expression implicitly coerced from 'Int?' to 'Any'}}
+  // expected-warning@-4 {{coercion of implicitly unwrappable value of type 'Int?' to 'Any' does not unwrap optional}}
   // expected-note@-5 {{provide a default value to avoid this warning}}{{40-40= ?? <#default value#>}}
   // expected-note@-6 {{force-unwrap the value to avoid this warning}}{{40-40=!}}
   // expected-note@-7 {{explicitly cast to 'Any' with 'as Any' to silence this warning}}{{40-40= as Any}}
 }
+
+func takesAny_sr10199(_ x: Any) {}
+
+let fn_sr10199: (() -> Int?)! = { return nil }
+takesAny_sr10199(fn_sr10199()) // expected-warning {{expression implicitly coerced from 'Int?' to 'Any'}}
+// expected-note@-1 {{provide a default value to avoid this warning}}
+// expected-note@-2 {{force-unwrap the value to avoid this warning}}
+// expected-note@-3 {{explicitly cast to 'Any' with 'as Any' to silence this warning}}