[5.0] Sema: Request the layout for generic parameters if there is a body

Cherry-picked: "Merge pull request #14411 from
aschwaighofer/sema_require_layout_generic_params"

Generic parameters can become sources of metadata types and
conformances. To access them the layout needs to be available to IRGen.

rdar://37086144
SR-6879

Author: aschwaighofer

lib/Sema/CSApply.cpp

@@ -7531,6 +7531,10 @@ namespace {
         if (tc.coerceParameterListToType(params, closure, fnType))
           return { false, nullptr };
 
+        // Require layout of dependent types that could be used to materialize
+        // metadata types/conformances during IRGen.
+        tc.requestRequiredNominalTypeLayoutForParameters(params);
+
         // If this is a single-expression closure, convert the expression
         // in the body to the result type of the closure.
         if (closure->hasSingleExpressionBody()) {

lib/Sema/TypeCheckPattern.cpp

@@ -775,6 +775,25 @@ static bool validateParameterType(ParamDecl *decl, DeclContext *DC,
   return hadError;
 }
 
+/// Request nominal layout for any types that could be sources of typemetadata
+/// or conformances.
+void TypeChecker::requestRequiredNominalTypeLayoutForParameters(
+    ParameterList *PL) {
+  for (auto param : *PL) {
+    if (!param->hasType())
+      continue;
+
+    // Generic types are sources for typemetadata and conformances. If a
+    // parameter is of dependent type then the body of a function with said
+    // parameter could potentially require the generic type's layout to
+    // recover them.
+    if (auto *nominalDecl = dyn_cast_or_null<NominalTypeDecl>(
+            param->getType()->getAnyGeneric())) {
+      requestNominalLayout(nominalDecl);
+    }
+  }
+}
+
 /// Type check a parameter list.
 bool TypeChecker::typeCheckParameterList(ParameterList *PL, DeclContext *DC,
                                          TypeResolutionOptions options,

lib/Sema/TypeCheckStmt.cpp

@@ -1373,6 +1373,9 @@ bool TypeChecker::typeCheckAbstractFunctionBody(AbstractFunctionDecl *AFD) {
   if (DebugTimeFunctionBodies || WarnLongFunctionBodies)
     timer.emplace(AFD, DebugTimeFunctionBodies, WarnLongFunctionBodies);
 
+  for (auto paramList : AFD->getParameterLists())
+    requestRequiredNominalTypeLayoutForParameters(paramList);
+
   if (typeCheckAbstractFunctionBodyUntil(AFD, SourceLoc()))
     return true;
 

lib/Sema/TypeChecker.h

@@ -1810,11 +1810,15 @@ class TypeChecker final : public LazyResolver {
 
   bool typeCheckCatchPattern(CatchStmt *S, DeclContext *dc);
 
+  /// Request nominal layout for any types that could be sources of typemetadata
+  /// or conformances.
+  void requestRequiredNominalTypeLayoutForParameters(ParameterList *PL);
+
   /// Type check a parameter list.
   bool typeCheckParameterList(ParameterList *PL, DeclContext *dc,
                               TypeResolutionOptions options,
                               GenericTypeResolver &resolver);
-  
+
   /// Coerce a pattern to the given type.
   ///
   /// \param P The pattern, which may be modified by this coercion.

test/multifile/Inputs/require-layout-generic-class.swift

@@ -0,0 +1,13 @@
+public class Base<T> {
+  var t: T
+  init(_ a: T) {
+    t = a
+  }
+}
+
+public class Sub<T> : Base<T> {
+}
+
+public func requestTypeThrough<T>(closure: (Sub<T>) -> (), arg: T) {
+  closure(Sub(arg))
+}

test/multifile/require-layout-generic-arg-closure.swift

@@ -0,0 +1,29 @@
+// RUN: %target-swift-frontend -module-name test -emit-ir -verify -primary-file %s %S/Inputs/require-layout-generic-class.swift | %FileCheck --check-prefix=FILE1 %s
+// RUN: %target-swift-frontend -module-name test -emit-ir -verify %s -primary-file %S/Inputs/require-layout-generic-class.swift | %FileCheck --check-prefix=FILE2 %s
+
+// REQUIRES: CPU=x86_64
+
+// The offset of the typemetadata in the class typemetadata must match.
+
+// FILE1-LABEL: define internal swiftcc void @"$S4test12requestType21xyx_tlFyAA3SubCyxGcfU_"(%T4test3SubC*)
+// FILE1: entry:
+// FILE1:   [[T1:%.*]] = bitcast %T4test3SubC* %0 to %swift.type**
+// FILE1:   [[TYPEMETADATA:%.*]] = load %swift.type*, %swift.type** [[T1]]
+// FILE1:   [[T2:%.*]] = bitcast %swift.type* [[TYPEMETADATA]] to %swift.type**
+// This offset of T needs to be the same as the offset below.
+// FILE1:   [[T_PTR:%.*]] = getelementptr inbounds %swift.type*, %swift.type** [[T2]], i64 16
+// FILE1:   [[T:%.*]] = load %swift.type*, %swift.type** [[T_PTR]]
+// FILE1:   call %swift.type* @"$S4test3SubCMa"(%swift.type* [[T]])
+
+public func requestType2<T>(x: T) {
+  requestTypeThrough(closure: { x in print(x) }, arg: x)
+}
+// FILE2-LABEL: define private %swift.type* @create_generic_metadata_Sub(%swift.type_pattern*, i8**)
+// FILE2:   [[T_ADDR:%.*]] = bitcast i8** %1 to %swift.type**
+// FILE2:   [[T:%.*]] = load %swift.type*, %swift.type** %2
+// FILE2:   [[CLASSMETADATA:%.*]] = call %swift.type* @swift_allocateGenericClassMetadata
+// FILE2:   [[ADDR:%.*]] = bitcast %swift.type* [[CLASSMETADATA]] to i8**
+// This offset of T here needs to be the same as the offset above.
+// FILE2:   [[T_IN_CLASSMETADATA:%.*]] = getelementptr inbounds i8*, i8** [[ADDR]], i64 16
+// FILE2:   [[T2:%.*]] = bitcast %swift.type* [[T]] to i8*
+// FILE2:   store i8* [[T2]], i8** [[T_IN_CLASSMETADATA]]

test/multifile/require-layout-generic-arg-subscript.swift

@@ -0,0 +1,33 @@
+// RUN: %target-swift-frontend -module-name test -emit-ir -verify -primary-file %s %S/Inputs/require-layout-generic-class.swift | %FileCheck --check-prefix=FILE1 %s
+// RUN: %target-swift-frontend -module-name test -emit-ir -verify %s -primary-file %S/Inputs/require-layout-generic-class.swift | %FileCheck --check-prefix=FILE2 %s
+
+// REQUIRES: CPU=x86_64
+
+// The offset of the typemetadata in the class typemetadata must match.
+
+// FILE1: define hidden swiftcc i64 @"$S4test12AccessorTestCySiAA3SubCyxGcluig"(%T4test3SubC*, %T4test12AccessorTestC* swiftself)
+// FILE1:   [[T1:%.*]] = bitcast %T4test3SubC* %0 to %swift.type**
+// FILE1:   [[TYPEMETADATA:%.*]] = load %swift.type*, %swift.type** [[T1]]
+// FILE1:   [[T2:%.*]] = bitcast %swift.type* [[TYPEMETADATA]] to %swift.type**
+// This offset must match the offset below.
+// FILE1:   [[T_IN_CLASSMETADATA:%.*]] = getelementptr inbounds %swift.type*, %swift.type** [[T2]], i64 16
+// FILE1:   [[T:%.*]] = load %swift.type*, %swift.type** [[T_IN_CLASSMETADATA]]
+// FILE1:   call %swift.type* @swift_getMetatypeMetadata(%swift.type* [[T]])
+public class AccessorTest {
+  subscript<T>(_ a: Sub<T>) -> Int {
+    get {
+      print(T.self)
+      return 1
+    }
+  }
+}
+
+// FILE2-LABEL: define private %swift.type* @create_generic_metadata_Sub(%swift.type_pattern*, i8**)
+// FILE2:   [[T_ADDR:%.*]] = bitcast i8** %1 to %swift.type**
+// FILE2:   [[T:%.*]] = load %swift.type*, %swift.type** %2
+// FILE2:   [[CLASSMETADATA:%.*]] = call %swift.type* @swift_allocateGenericClassMetadata
+// FILE2:   [[ADDR:%.*]] = bitcast %swift.type* [[CLASSMETADATA]] to i8**
+// This offset must match the offset above.
+// FILE2:   [[T_IN_CLASSMETADATA:%.*]] = getelementptr inbounds i8*, i8** [[ADDR]], i64 16
+// FILE2:   [[T2:%.*]] = bitcast %swift.type* [[T]] to i8*
+// FILE2:   store i8* [[T2]], i8** [[T_IN_CLASSMETADATA]]

test/multifile/require-layout-generic-arg.swift

@@ -0,0 +1,27 @@
+// RUN: %target-swift-frontend -module-name test -emit-ir -verify -primary-file %s %S/Inputs/require-layout-generic-class.swift | %FileCheck --check-prefix=FILE1 %s
+// RUN: %target-swift-frontend -module-name test -emit-ir -verify %s -primary-file %S/Inputs/require-layout-generic-class.swift | %FileCheck --check-prefix=FILE2 %s
+
+// REQUIRES: CPU=x86_64
+
+// The offset of the typemetadata in the class typemetadata must match.
+
+// FILE1-LABEL: define{{.*}} swiftcc void @"$S4test11requestTypeyyAA3SubCyxGlF"(%T4test3SubC*)
+// FILE1:  [[T1:%.*]] = bitcast %T4test3SubC* %0 to %swift.type**
+// FILE1:  [[TYPEMETADATA:%.*]] = load %swift.type*, %swift.type** [[T1]]
+// FILE1:  [[T2:%.*]] = bitcast %swift.type* [[TYPEMETADATA]] to %swift.type**
+// This offset must match the offset below.
+// FILE1:  [[T_PTR:%.*]] = getelementptr inbounds %swift.type*, %swift.type** [[T2]], i64 16
+// FILE1:  [[T:%.*]] = load %swift.type*, %swift.type** [[T_PTR]]
+public func requestType<T>(_ c: Sub<T>) {
+  print(T.self)
+}
+
+// FILE2-LABEL: define private %swift.type* @create_generic_metadata_Sub(%swift.type_pattern*, i8**)
+// FILE2:   [[T_ADDR:%.*]] = bitcast i8** %1 to %swift.type**
+// FILE2:   [[T:%.*]] = load %swift.type*, %swift.type** %2
+// FILE2:   [[CLASSMETADATA:%.*]] = call %swift.type* @swift_allocateGenericClassMetadata
+// FILE2:   [[ADDR:%.*]] = bitcast %swift.type* [[CLASSMETADATA]] to i8**
+// This offset must match the offset above.
+// FILE2:   [[T_IN_CLASSMETADATA:%.*]] = getelementptr inbounds i8*, i8** [[ADDR]], i64 16
+// FILE2:   [[T2:%.*]] = bitcast %swift.type* [[T]] to i8*
+// FILE2:   store i8* [[T2]], i8** [[T_IN_CLASSMETADATA]]

test/multifile/require-layout/main.swift

@@ -0,0 +1,12 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-build-swift %S/../require-layout-generic-arg.swift %S/../Inputs/require-layout-generic-class.swift %s -o %t/test
+// RUN: %target-run %t/test | %FileCheck %s
+
+// REQUIRES: executable_test
+
+func test() {
+  requestType(Sub(1))
+}
+
+// CHECK: Int
+test()

test/multifile/require-layout2/main.swift

@@ -0,0 +1,12 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-build-swift %S/../require-layout-generic-arg-closure.swift %S/../Inputs/require-layout-generic-class.swift %s -o %t/test
+// RUN: %target-run %t/test | %FileCheck %s
+
+// REQUIRES: executable_test
+
+func test() {
+  requestType2(x: 1)
+}
+
+// CHECK: test.Sub<Swift.Int>
+test()

test/multifile/require-layout3/main.swift

@@ -0,0 +1,12 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-build-swift %S/../require-layout-generic-arg-subscript.swift %S/../Inputs/require-layout-generic-class.swift %s -o %t/test
+// RUN: %target-run %t/test | %FileCheck %s
+
+// REQUIRES: executable_test
+
+func test() {
+  _ = AccessorTest()[Sub(1)]
+}
+
+// CHECK: Int
+test()