[cxx-interop][IRGen] Walk initializer decls when walking constructor decls

lib/IRGen/GenClangDecl.cpp

@@ -53,6 +53,15 @@ class ClangDeclFinder
     return true;
   }
 
+  bool VisitCXXConstructorDecl(clang::CXXConstructorDecl *CXXCD) {
+    callback(CXXCD);
+    for (clang::CXXCtorInitializer *CXXCI : CXXCD->inits()) {
+      if (clang::FieldDecl *FD = CXXCI->getMember())
+        callback(FD);
+    }
+    return true;
+  }
+
   bool VisitCXXConstructExpr(clang::CXXConstructExpr *CXXCE) {
     callback(CXXCE->getConstructor());
     return true;

test/Interop/Cxx/class/inline-function-codegen/Inputs/constructor-calls-function-from-nested-calls.h

@@ -0,0 +1,13 @@
+#ifndef TEST_INTEROP_CXX_CLASS_INLINE_FUNCTION_CODEGEN_INPUTS_CONSTRUCTOR_CALLS_FUNCTION_FROM_NESTED_CALLS_H
+#define TEST_INTEROP_CXX_CLASS_INLINE_FUNCTION_CODEGEN_INPUTS_CONSTRUCTOR_CALLS_FUNCTION_FROM_NESTED_CALLS_H
+
+inline int get42Level4() { return 42; }
+inline int get42Level3() { return get42Level4(); }
+inline int get42Level2() { return get42Level3(); }
+inline int get42Level1() { return get42Level2(); }
+
+struct Hold42WithLongInitCallGraph {
+  int m = get42Level1();
+};
+
+#endif // TEST_INTEROP_CXX_CLASS_INLINE_FUNCTION_THROUGH_MEMBER_INPUTS_CONSTRUCTOR_CALLS_FUNCTION_FROM_NESTED_STRUCT_H

test/Interop/Cxx/class/inline-function-codegen/Inputs/constructor-calls-function-from-nested-struct.h

@@ -14,4 +14,18 @@ inline int callConstructor(int value) {
   return IncrementUser::Incrementor(value).value;
 }
 
+inline int get42() { return 42; }
+
+struct HoldMemberThatHolds42 {
+  struct Hold42 {
+    int m = get42();
+  };
+
+  Hold42 holder;
+};
+
+struct HoldMemberThatHoldsMemberThatHolds42 {
+  HoldMemberThatHolds42 holder;
+};
+
 #endif // TEST_INTEROP_CXX_CLASS_INLINE_FUNCTION_THROUGH_MEMBER_INPUTS_CONSTRUCTOR_CALLS_FUNCTION_FROM_NESTED_STRUCT_H

test/Interop/Cxx/class/inline-function-codegen/Inputs/constructor-calls-function.h

@@ -10,4 +10,19 @@ struct Incrementor {
 
 inline int callConstructor(int value) { return Incrementor(value).incrementee; }
 
+inline int get42() { return 42; }
+
+template <typename T>
+T passThroughArgT(T t) {
+  return t;
+}
+
+struct Hold42 {
+  int m = get42();
+};
+
+struct Hold23 {
+  int m = passThroughArgT<int>(23);
+};
+
 #endif // TEST_INTEROP_CXX_CLASS_INLINE_FUNCTION_THROUGH_MEMBER_INPUTS_CONSTRUCTOR_CALLS_FUNCTION_H

test/Interop/Cxx/class/inline-function-codegen/Inputs/module.modulemap

@@ -8,6 +8,11 @@ module ConstructorCallsFunctionFromNestedStruct {
   requires cplusplus
 }
 
+module ConstructorCallsFunctionFromNestedCalls {
+  header "constructor-calls-function-from-nested-calls.h"
+  requires cplusplus
+}
+
 module ConstructorCallsMethod {
   header "constructor-calls-method.h"
   requires cplusplus

test/Interop/Cxx/class/inline-function-codegen/constructor-calls-function-execution.swift

@@ -7,8 +7,18 @@ import StdlibUnittest
 
 var MembersTestSuite = TestSuite("MembersTestSuite")
 
-MembersTestSuite.test("constructor calls function") {
+MembersTestSuite.test("constructor calls function (explicit)") {
   expectEqual(42, callConstructor(41))
 }
 
+MembersTestSuite.test("constructor calls function (implicit)") {
+  let holder = Hold42()
+  expectEqual(42, holder.m)
+}
+
+MembersTestSuite.test("constructor calls template function (implicit)") {
+  let holder = Hold23()
+  expectEqual(23, holder.m)
+}
+
 runAllTests()

test/Interop/Cxx/class/inline-function-codegen/constructor-calls-function-from-nested-calls-execution.swift

@@ -0,0 +1,15 @@
+// RUN: %target-run-simple-swift(-I %S/Inputs -Xfrontend -enable-cxx-interop)
+//
+// REQUIRES: executable_test
+
+import ConstructorCallsFunctionFromNestedCalls
+import StdlibUnittest
+
+var MembersTestSuite = TestSuite("MembersTestSuite")
+
+MembersTestSuite.test("constructor calls function from nested calls") {
+  let holder = Hold42WithLongInitCallGraph()
+  expectEqual(42, holder.m)
+}
+
+runAllTests()

test/Interop/Cxx/class/inline-function-codegen/constructor-calls-function-from-nested-calls-irgen.swift

@@ -0,0 +1,10 @@
+// RUN: %target-swift-emit-ir %s -I %S/Inputs -enable-cxx-interop | %FileCheck %s
+
+import ConstructorCallsFunctionFromNestedCalls
+
+let a = Hold42WithLongInitCallGraph()
+
+// CHECK-DAG: define linkonce_odr{{( dso_local)?}} i32 @{{_Z11get42Level1v|"\?get42Level1@@YAHXZ"}}
+// CHECK-DAG: define linkonce_odr{{( dso_local)?}} i32 @{{_Z11get42Level2v|"\?get42Level2@@YAHXZ"}}
+// CHECK-DAG: define linkonce_odr{{( dso_local)?}} i32 @{{_Z11get42Level3v|"\?get42Level3@@YAHXZ"}}
+// CHECK-DAG: define linkonce_odr{{( dso_local)?}} i32 @{{_Z11get42Level4v|"\?get42Level4@@YAHXZ"}}

test/Interop/Cxx/class/inline-function-codegen/constructor-calls-function-from-nested-struct-execution.swift

@@ -7,8 +7,13 @@ import StdlibUnittest
 
 var MembersTestSuite = TestSuite("MembersTestSuite")
 
-MembersTestSuite.test("constructor calls function from nested struct") {
+MembersTestSuite.test("constructor calls function from nested struct (explicit)") {
   expectEqual(42, callConstructor(41))
 }
 
+MembersTestSuite.test("constructor calls function from nested struct (implicit)") {
+  let holder = HoldMemberThatHolds42()
+  expectEqual(42, holder.holder.m)
+}
+
 runAllTests()

test/Interop/Cxx/class/inline-function-codegen/constructor-calls-function-from-nested-struct-irgen.swift

@@ -6,4 +6,10 @@ public func getIncrementorValue() -> CInt {
   return callConstructor(41)
 }
 
-// CHECK: define linkonce_odr{{( dso_local)?}} i32 @{{_Z9incrementi|"\?increment@@YAHH@Z"}}(i32 %t)
+let a = HoldMemberThatHolds42()
+let b = HoldMemberThatHoldsMemberThatHolds42()
+
+let sum = a.holder.m + b.holder.holder.m
+
+// CHECK-DAG: define linkonce_odr{{( dso_local)?}} i32 @{{_Z9incrementi|"\?increment@@YAHH@Z"}}(i32 %t)
+// CHECK-DAG: define linkonce_odr{{( dso_local)?}} i32 @{{_Z5get42v|"\?get42@@YAHXZ"}}

test/Interop/Cxx/class/inline-function-codegen/constructor-calls-function-irgen.swift

@@ -6,4 +6,11 @@ public func getIncrementorValue() -> CInt {
   return callConstructor(41)
 }
 
-// CHECK: define linkonce_odr{{( dso_local)?}} i32 @{{_Z9incrementi|"\?increment@@YAHH@Z"}}(i32 %t)
+let a = Hold42()
+let b = Hold23()
+
+let sum = a.m + b.m
+
+// CHECK-DAG: define linkonce_odr{{( dso_local)?}} i32 @{{_Z9incrementi|"\?increment@@YAHH@Z"}}(i32 %t)
+// CHECK-DAG: define linkonce_odr{{( dso_local)?}} i32 @{{_Z5get42v|"\?get42@@YAHXZ"}}
+// CHECK-DAG: define linkonce_odr{{( dso_local)?}} i32 @{{_Z15passThroughArgTIiET_S0_|"\?\?\$passThroughArgT@H@@YAHH@Z"}}