[Strict memory safety] Provide argument-specific diagnostics for calls

include/swift/AST/DiagnosticsSema.def

@@ -8341,6 +8341,15 @@ NOTE(note_reference_to_unsafe_decl,none,
 NOTE(note_reference_to_unsafe_typed_decl,none,
      "%select{reference|call}0 to %kind1 involves unsafe type %2",
      (bool, const ValueDecl *, Type))
+NOTE(note_unsafe_call_decl_argument_named,none,
+     "argument %1 in call to %kindbase0 has unsafe type %2",
+     (const ValueDecl *, Identifier, Type))
+NOTE(note_unsafe_call_decl_argument_indexed,none,
+     "argument #%1 in call to %kindbase0 has unsafe type %2",
+     (const ValueDecl *, unsigned, Type))
+NOTE(note_unsafe_call_argument_indexed,none,
+     "argument #%0 in call has unsafe type %1",
+     (unsigned, Type))
 NOTE(note_reference_to_unsafe_through_typealias,none,
      "reference to %kind0 whose underlying type involves unsafe type %1",
      (const ValueDecl *, Type))
@@ -8402,9 +8411,9 @@ GROUPED_WARNING(unsafe_without_unsafe,StrictMemorySafety,none,
       "expression uses unsafe constructs but is not marked with 'unsafe'", ())
 GROUPED_WARNING(for_unsafe_without_unsafe,StrictMemorySafety,none,
       "for-in loop uses unsafe constructs but is not marked with 'unsafe'", ())
-GROUPED_WARNING(no_unsafe_in_unsafe,StrictMemorySafety,none,
+WARNING(no_unsafe_in_unsafe,none,
         "no unsafe operations occur within 'unsafe' expression", ())
-GROUPED_WARNING(no_unsafe_in_unsafe_for,StrictMemorySafety,none,
+WARNING(no_unsafe_in_unsafe_for,none,
         "no unsafe operations occur within 'unsafe' for-in loop", ())
 NOTE(make_subclass_unsafe,none,
      "make class %0 '@unsafe' to allow unsafe overrides of safe superclass "

include/swift/AST/UnsafeUse.h

@@ -53,6 +53,8 @@ class UnsafeUse {
     ReferenceToUnsafeThroughTypealias,
     /// A call to an unsafe declaration.
     CallToUnsafe,
+    /// An unsafe argument in a call.
+    CallArgument,
     /// A @preconcurrency import.
     PreconcurrencyImport,
     /// A use of withoutActuallyEscaping that lacks enforcement that the
@@ -91,6 +93,15 @@ class UnsafeUse {
 
     MakeTemporarilyEscapableExpr *temporarilyEscaping;
 
+    struct {
+      Expr *call;
+      const Decl *calleeDecl;
+      TypeBase *paramType;
+      const void *argumentName;
+      unsigned argumentIndex;
+      Expr *argument;
+    } callArgument;
+
     const ImportDecl *importDecl;
   } storage;
 
@@ -201,6 +212,19 @@ class UnsafeUse {
                         decl, type, location);
   }
 
+  static UnsafeUse forCallArgument(
+      Expr *call, const Decl *calleeDecl, Type paramType,
+      Identifier argumentName, unsigned argumentIndex, Expr *argument) {
+    UnsafeUse result(CallArgument);
+    result.storage.callArgument.call = call;
+    result.storage.callArgument.calleeDecl = calleeDecl;
+    result.storage.callArgument.paramType = paramType.getPointer();
+    result.storage.callArgument.argumentName = argumentName.getAsOpaquePointer();
+    result.storage.callArgument.argumentIndex = argumentIndex;
+    result.storage.callArgument.argument = argument;
+    return result;
+  }
+
   static UnsafeUse forTemporarilyEscaping(MakeTemporarilyEscapableExpr *expr) {
     UnsafeUse result(TemporarilyEscaping);
     result.storage.temporarilyEscaping = expr;
@@ -242,6 +266,9 @@ class UnsafeUse {
       return SourceLoc(
           llvm::SMLoc::getFromPointer((const char *)storage.entity.location));
 
+    case CallArgument:
+      return storage.callArgument.call->getLoc();
+
     case TemporarilyEscaping:
       return storage.temporarilyEscaping->getLoc();
 
@@ -257,6 +284,7 @@ class UnsafeUse {
     case Witness:
     case TemporarilyEscaping:
     case PreconcurrencyImport:
+    case CallArgument:
       // Cannot replace location.
       return;
 
@@ -298,6 +326,9 @@ class UnsafeUse {
     case CallToUnsafe:
       return storage.entity.decl;
 
+    case CallArgument:
+      return storage.callArgument.calleeDecl;
+
     case UnsafeConformance:
     case TemporarilyEscaping:
       return nullptr;
@@ -330,6 +361,7 @@ class UnsafeUse {
     case ReferenceToUnsafeThroughTypealias:
     case ReferenceToUnsafeStorage:
     case CallToUnsafe:
+    case CallArgument:
     case UnsafeConformance:
     case PreconcurrencyImport:
     case TemporarilyEscaping:
@@ -360,6 +392,9 @@ class UnsafeUse {
     case CallToUnsafe:
       return storage.entity.type;
 
+    case CallArgument:
+      return storage.callArgument.paramType;
+
     case TemporarilyEscaping:
       return storage.temporarilyEscaping->getOpaqueValue()->getType();
     }
@@ -386,11 +421,24 @@ class UnsafeUse {
     case ReferenceToUnsafeStorage:
     case ReferenceToUnsafeThroughTypealias:
     case CallToUnsafe:
+    case CallArgument:
     case TemporarilyEscaping:
     case PreconcurrencyImport:
       return ProtocolConformanceRef::forInvalid();
     }
   }
+
+  /// Get information about the call argument.
+  ///
+  /// Produces the argument name, argument index, and argument expression for
+  /// a unsafe use describing a call argument.
+  std::tuple<Identifier, unsigned, Expr *> getCallArgument() const {
+    assert(getKind() == CallArgument);
+    return std::make_tuple(
+        Identifier::getFromOpaquePointer(storage.callArgument.argumentName),
+        storage.callArgument.argumentIndex,
+        storage.callArgument.argument);
+  }
 };
 
 } // end namespace swift

lib/Sema/CSApply.cpp

@@ -8149,7 +8149,7 @@ Expr *ExprRewriter::convertLiteralInPlace(
     Diag<> brokenProtocolDiag, Diag<> brokenBuiltinProtocolDiag) {
   // If coercing a literal to an unresolved type, we don't try to look up the
   // witness members, just do it.
-  if (type->is<UnresolvedType>()) {
+  if (type->is<UnresolvedType>() || type->is<ErrorType>()) {
     cs.setType(literal, type);
     return literal;
   }

lib/Sema/TypeCheckAvailability.cpp

@@ -2699,6 +2699,7 @@ diagnoseDeclUnsafe(ConcreteDeclRef declRef, SourceRange R,
 
   SourceLoc diagLoc = call ? call->getLoc() : R.Start;
   enumerateUnsafeUses(declRef, diagLoc, call != nullptr,
+                      /*skipTypeCheck=*/false,
                       [&](UnsafeUse unsafeUse) {
     unsafeUses->push_back(unsafeUse);
     return false;