Fix callable type-checking.

lib/Sema/CSSimplify.cpp

@@ -4587,57 +4587,54 @@ ConstraintSystem::simplifyApplicableFnConstraint(
 
   // SWIFT_ENABLE_TENSORFLOW
   // Handle applications of types with `call` methods.
-  if (auto nominal = desugar2->getAnyNominal()) {
-    auto &ctx = getASTContext();
-    // Get all `call` methods of the nominal type.
-    SmallVector<CallDecl *, 4> callDecls;
-    auto candidates = TC.lookupMember(DC, nominal->getDeclaredTypeInContext(),
-                                      DeclName(ctx.getIdentifier("$call")));
-    for (auto entry : candidates) {
-      auto callDecl = dyn_cast<CallDecl>(entry.getValueDecl());
-      if (!callDecl)
-        continue;
-      callDecls.push_back(callDecl);
-    }
-
-     // Handle `call` methods calls.
-    if (!callDecls.empty()) {
-      // Create a type variable for the `call` method.
-      auto loc = getConstraintLocator(locator);
-      auto tv = createTypeVariable(loc, TVO_CanBindToLValue);
-
-       // Record the `call` method overload set.
-      SmallVector<OverloadChoice, 4> choices;
-      for (auto candidate : callDecls) {
-        TC.validateDecl(candidate);
-        if (candidate->isInvalid()) continue;
-        choices.push_back(
-            OverloadChoice(type2, candidate, FunctionRefKind::SingleApply));
-      }
-      if (choices.empty()) return SolutionKind::Error;
-      addOverloadSet(tv, choices, DC, loc);
-
-       // Create type variables for each parameter type.
-      SmallVector<AnyFunctionType::Param, 4> tvParams;
-      for (unsigned i : range(func1->getNumParams())) {
-        auto param = func1->getParams()[i];
-        auto paramType = param.getPlainType();
-
-         auto *tvParam = createTypeVariable(loc);
-        auto locatorBuilder =
-            locator.withPathElement(LocatorPathElt::getTupleElement(i));
-        addConstraint(ConstraintKind::ArgumentConversion, paramType,
-                      tvParam, locatorBuilder);
-        tvParams.push_back(AnyFunctionType::Param(tvParam));
-      }
-      // Create target function type and an applicable function constraint.
-      AnyFunctionType *funcType =
-          FunctionType::get(tvParams, func1->getResult());
-      addConstraint(ConstraintKind::ApplicableFunction,
-                    funcType, tv, locator);
+  auto &ctx = getASTContext();
+  // Get all `call` methods of the nominal type.
+  SmallVector<CallDecl *, 4> callDecls;
+  auto candidates = TC.lookupMember(
+      DC, desugar2, DeclName(ctx.getIdentifier("$call")));
+  for (auto entry : candidates) {
+    auto callDecl = dyn_cast<CallDecl>(entry.getValueDecl());
+    if (!callDecl)
+      continue;
+    callDecls.push_back(callDecl);
+  }
+
+   // Handle `call` methods calls.
+  if (!callDecls.empty()) {
+    // Create a type variable for the `call` method.
+    auto loc = getConstraintLocator(locator);
+    auto tv = createTypeVariable(loc, TVO_CanBindToLValue);
+
+    // Record the `call` method overload set.
+    SmallVector<OverloadChoice, 4> choices;
+    for (auto candidate : callDecls) {
+      TC.validateDecl(candidate);
+      if (candidate->isInvalid()) continue;
+      choices.push_back(
+          OverloadChoice(type2, candidate, FunctionRefKind::SingleApply));
+    }
+    if (choices.empty()) return SolutionKind::Error;
+    addOverloadSet(tv, choices, DC, loc);
+
+    // Create type variables for each parameter type.
+    SmallVector<AnyFunctionType::Param, 4> tvParams;
+    for (unsigned i : range(func1->getNumParams())) {
+      auto param = func1->getParams()[i];
+      auto paramType = param.getPlainType();
+
+      auto *tvParam = createTypeVariable(loc);
+      auto locatorBuilder =
+          locator.withPathElement(LocatorPathElt::getTupleElement(i));
+      addConstraint(ConstraintKind::ArgumentConversion, paramType,
+                    tvParam, locatorBuilder);
+      tvParams.push_back(AnyFunctionType::Param(tvParam));
+    }
+    // Create target function type and an applicable function constraint.
+    AnyFunctionType *funcType =
+        FunctionType::get(tvParams, func1->getResult());
+    addConstraint(ConstraintKind::ApplicableFunction, funcType, tv, locator);
 
-       return SolutionKind::Solved;
-    }
+    return SolutionKind::Solved;
   }
 
   // Handle applications of @dynamicCallable types.

test/decl/call/protocol.swift

@@ -7,6 +7,9 @@ protocol P0 {
 func testProtocol(_ x: P0) {
   _ = x()
 }
+func testGeneric<T : P0>(_ x: T) {
+  _ = x()
+}
 
 protocol P1 {
   call func() -> Self