[cxx-interop] Remove impl for constexpr members (#60154)

* Remove impl for constexpr members

* Readd some tets

* Only remove import of static constexpr

Author: Huddie

lib/ClangImporter/ImportDecl.cpp

@@ -3273,49 +3273,8 @@ namespace {
       return nullptr;
     }
 
-    AccessorDecl *tryCreateConstexprAccessor(const clang::VarDecl *clangVar,
-                                             VarDecl *swiftVar) {
-      assert(clangVar->isConstexpr());
-      clangVar->evaluateValue();
-      auto evaluated = clangVar->getEvaluatedValue();
-      if (!evaluated)
-        return nullptr;
-
-      // If we have a constexpr var with an evaluated value, try to create an
-      // accessor for it. If we can remove all references to the global (which
-      // we should be able to do for constexprs) then we can remove the global
-      // entirely.
-      auto accessor = AccessorDecl::create(
-          Impl.SwiftContext, SourceLoc(), SourceLoc(), AccessorKind::Get,
-          swiftVar, SourceLoc(), StaticSpellingKind::KeywordStatic,
-          /*Async=*/false, /*AsyncLoc=*/SourceLoc(),
-          /*throws=*/false, SourceLoc(), /*genericParams*/ nullptr,
-          ParameterList::createEmpty(Impl.SwiftContext), swiftVar->getType(),
-          swiftVar->getDeclContext());
-      Expr *value = nullptr;
-      // TODO: add non-numeric types.
-      if (evaluated->isInt()) {
-        value = IntegerLiteralExpr::createFromUnsigned(
-            Impl.SwiftContext,
-            static_cast<unsigned>(
-                clangVar->getEvaluatedValue()->getInt().getZExtValue()));
-      } else if (evaluated->isFloat()) {
-        auto floatStr = evaluated->getAsString(Impl.getClangASTContext(),
-                                               clangVar->getType());
-        auto floatIdent = Impl.SwiftContext.getIdentifier(floatStr);
-        value = new (Impl.SwiftContext)
-            FloatLiteralExpr(floatIdent.str(), SourceLoc());
-      }
-      if (!value)
-        return nullptr;
-      auto returnStmt = new (Impl.SwiftContext) ReturnStmt(SourceLoc(), value);
-      auto body = BraceStmt::create(Impl.SwiftContext, SourceLoc(),
-                                    {returnStmt}, SourceLoc());
-      accessor->setBodyParsed(body);
-      return accessor;
-    }
-
     Decl *VisitVarDecl(const clang::VarDecl *decl) {
+
       // Variables are imported as... variables.
       ImportedName importedName;
       Optional<ImportedName> correctSwiftName;
@@ -3362,6 +3321,10 @@ namespace {
       if (dc->isTypeContext())
         isStatic = true;
 
+      // For now we don't import static constexpr
+      if (isStatic && decl->isConstexpr())
+        return nullptr;
+
       auto introducer = Impl.shouldImportGlobalAsLet(decl->getType())
                         ? VarDecl::Introducer::Let
                         : VarDecl::Introducer::Var;
@@ -3385,11 +3348,6 @@ namespace {
       if (correctSwiftName)
         markAsVariant(result, *correctSwiftName);
 
-      // For constexpr vars, we can create an accessor with a numeric literal.
-      if (decl->isConstexpr())
-        if (auto acc = tryCreateConstexprAccessor(decl, result))
-          result->setAccessors(SourceLoc(), {acc}, SourceLoc());
-
       return result;
     }
 

test/Interop/Cxx/static/constexpr-static-member-var.swift

@@ -11,8 +11,4 @@ import StdlibUnittest
 
 var ConstexprStaticMemberVarTestSuite = TestSuite("ConstexprStaticMemberVarTestSuite")
 
-ConstexprStaticMemberVarTestSuite.test("constexpr-static-member") {
-  expectEqual(139, WithConstexprStaticMember.definedInline)
-}
-
 runAllTests()

test/Interop/Cxx/static/static-member-var-irgen.swift

@@ -3,20 +3,6 @@
 // CHECK: @{{_ZN16WithStaticMember12staticMemberE|"\?staticMember@WithStaticMember@@2HA"}} = external {{(dso_local )?}}global i32, align 4
 // CHECK: @{{_ZN26WithIncompleteStaticMember10selfMemberE|"\?selfMember@WithIncompleteStaticMember@@2V1@A"}} = {{external|linkonce_odr}} {{(dso_local )?}}global %class.WithIncompleteStaticMember, align 4
 
-//TODO: This test uses only values of static const members, so it does not need
-//to depend on external definitions. However, our code generation pattern loads
-//the value dynamically. Instead, we should inline known constants. That would
-//allow Swift code to even read the value of WithIncompleteStaticMember::notDefined.
-// CHECK: @{{_ZN21WithConstStaticMember7definedE|"\?defined@WithConstStaticMember@@2HB"}} = {{available_externally|linkonce_odr}} {{(dso_local )?}}constant i32 48, {{(comdat, )?}}align 4
-// CHECK: @{{_ZN21WithConstStaticMember16definedOutOfLineE|"\?definedOutOfLine@WithConstStaticMember@@2HB"}} = external {{(dso_local )?}}constant i32, align 4
-
-// Make sure we remove constexpr globals after all uses have been inlined.
-// CHECK-NOT: _ZN25WithConstexprStaticMember13definedInlineE
-// CHECK-NOT: ?definedInline@WithConstexprStaticMember@@2HB
-// CHECK-NOT: @_ZN25WithConstexprStaticMember20definedInlineWithArgE
-// CHECK-NOT: @_ZN25WithConstexprStaticMember18definedInlineFloatE
-// CHECK-NOT: @_ZN25WithConstexprStaticMember23definedInlineFromMethodE
-
 import StaticMemberVar
 
 public func readStaticMember() -> CInt {
@@ -54,55 +40,17 @@ public func writeSelfMember(_ m: WithIncompleteStaticMember) {
 // public func readNotDefinedConstMember() -> CInt {
 //   return WithConstStaticMember.notDefined
 // }
-
 public func readDefinedConstMember() -> CInt {
   return WithConstStaticMember.defined
 }
 
 // CHECK: define {{(protected |dllexport )?}}swiftcc i32 @"$s4main22readDefinedConstMembers5Int32VyF"() #0
 // CHECK: [[VALUE:%.*]] = load i32, i32* getelementptr inbounds (%Ts5Int32V, %Ts5Int32V* bitcast (i32* @{{_ZN21WithConstStaticMember7definedE|"\?defined@WithConstStaticMember@@2HB"}} to %Ts5Int32V*), i32 0, i32 0), align 4
 // CHECK: ret i32 [[VALUE]]
-
 public func readDefinedOutOfLineConstMember() -> CInt {
   return WithConstStaticMember.definedOutOfLine
 }
 
 // CHECK: define {{(protected |dllexport )?}}swiftcc i32 @"$s4main31readDefinedOutOfLineConstMembers5Int32VyF"() #0
 // CHECK: [[VALUE:%.*]] = load i32, i32* getelementptr inbounds (%Ts5Int32V, %Ts5Int32V* bitcast (i32* @{{_ZN21WithConstStaticMember16definedOutOfLineE|"\?definedOutOfLine@WithConstStaticMember@@2HB"}} to %Ts5Int32V*), i32 0, i32 0), align 4
-// CHECK: ret i32 [[VALUE]]
-
-public func readConstexprStaticIntMembers() {
-  let x = WithConstexprStaticMember.definedInline
-  let y = WithConstexprStaticMember.definedInlineWithArg
-}
-
-// CHECK-LABEL: define {{(protected |dllexport )?}}swiftcc void @"$s4main29readConstexprStaticIntMembersyyF"()
-// CHECK: call swiftcc i32 @"$sSo25WithConstexprStaticMemberV13definedInlines5Int32VvgZ"()
-// CHECK: call swiftcc i32 @"$sSo25WithConstexprStaticMemberV013definedInlineA3Args5Int32VvgZ"()
-// CHECK: ret void
-
-// CHECK-LABEL: define linkonce_odr {{.*}}swiftcc i32 @"$sSo25WithConstexprStaticMemberV13definedInlines5Int32VvgZ"()
-// CHECK-NEXT: entry
-// CHECK-NEXT: ret i32 139
-
-// CHECK-LABEL: define linkonce_odr {{.*}}swiftcc i32 @"$sSo25WithConstexprStaticMemberV013definedInlineA3Args5Int32VvgZ"()
-// CHECK-NEXT: entry
-// CHECK-NEXT: ret i32 42
-
-public func readConstexprStaticFloatMembers() {
-  let x = WithConstexprStaticMember.definedInlineFloat
-  let y = WithConstexprStaticMember.definedInlineFromMethod
-}
-
-// CHECK-LABEL: define {{(protected |dllexport )?}}swiftcc void @"$s4main31readConstexprStaticFloatMembersyyF"()
-// CHECK: call swiftcc float @"$sSo25WithConstexprStaticMemberV18definedInlineFloatSfvgZ"()
-// CHECK: call swiftcc float @"$sSo25WithConstexprStaticMemberV23definedInlineFromMethodSfvgZ"()
-// CHECK: ret void
-
-// CHECK-LABEL: define linkonce_odr {{.*}}swiftcc float @"$sSo25WithConstexprStaticMemberV18definedInlineFloatSfvgZ"()
-// CHECK-NEXT: entry
-// CHECK-NEXT: ret float 1.390000e+02
-
-// CHECK-LABEL: define linkonce_odr {{.*}}swiftcc float @"$sSo25WithConstexprStaticMemberV23definedInlineFromMethodSfvgZ"()
-// CHECK-NEXT: entry
-// CHECK-NEXT: ret float 4.200000e+01
+// CHECK: ret i32 [[VALUE]]

test/Interop/Cxx/static/static-member-var-silgen.swift

@@ -4,11 +4,6 @@
 // CHECK: sil_global public_external @{{_ZN16WithStaticMember12staticMemberE|\?staticMember@WithStaticMember@@2HA}} : $Int32
 // CHECK: // clang name: WithIncompleteStaticMember::selfMember
 // CHECK: sil_global public_external @{{_ZN26WithIncompleteStaticMember10selfMemberE|\?selfMember@WithIncompleteStaticMember@@2V1@A}} : $WithIncompleteStaticMember
-// CHECK: // clang name: WithConstStaticMember::defined
-// CHECK: sil_global public_external [let] @{{_ZN21WithConstStaticMember7definedE|\?defined@WithConstStaticMember@@2HB}} : $Int32
-// CHECK: // clang name: WithConstStaticMember::definedOutOfLine
-// CHECK: sil_global public_external [let] @{{_ZN21WithConstStaticMember16definedOutOfLineE|\?definedOutOfLine@WithConstStaticMember@@2HB}} : $Int32
-
 import StaticMemberVar
 
 func readStaticMember() -> CInt {
@@ -49,12 +44,10 @@ func writeSelfMember(_ m: WithIncompleteStaticMember) {
 // CHECK: [[ADDR:%.*]] = global_addr @{{_ZN26WithIncompleteStaticMember10selfMemberE|\?selfMember@WithIncompleteStaticMember@@2V1@A}} : $*WithIncompleteStaticMember
 // CHECK: [[ACCESS:%.*]] = begin_access [modify] [dynamic] [[ADDR]] : $*WithIncompleteStaticMember
 // CHECK:  store %0 to [[ACCESS]] : $*WithIncompleteStaticMember
-
 //TODO fix undefined reference to `WithConstStaticMember::notDefined`.
 // func readNotDefinedConstMember() -> CInt {
 //   return WithConstStaticMember.notDefined
 // }
-
 func readDefinedConstMember() -> CInt {
   return WithConstStaticMember.defined
 }
@@ -63,25 +56,6 @@ func readDefinedConstMember() -> CInt {
 // CHECK: [[ADDR:%.*]] = global_addr @{{_ZN21WithConstStaticMember7definedE|\?defined@WithConstStaticMember@@2HB}} : $*Int32
 // CHECK: [[VALUE:%.*]] = load [[ADDR]] : $*Int32
 // CHECK: return [[VALUE]] : $Int32
-
 func readDefinedOutOfLineConstMember() -> CInt {
   return WithConstStaticMember.definedOutOfLine
-}
-
-// CHECK: sil hidden @$s4main25readConstexprStaticMembers5Int32VyF : $@convention(thin) () -> Int32
-// CHECK: [[META:%.*]] = metatype $@thin WithConstexprStaticMember.Type
-// CHECK: [[ACC:%.*]] = function_ref @$sSo25WithConstexprStaticMemberV13definedInlines5Int32VvgZ : $@convention(method) (@thin WithConstexprStaticMember.Type) -> Int32
-// CHECK: [[OUT:%.*]] = apply [[ACC]]([[META]]) : $@convention(method) (@thin WithConstexprStaticMember.Type) -> Int32
-// CHECK: return [[OUT]] : $Int32
-// CHECK-LABEL: end sil function '$s4main25readConstexprStaticMembers5Int32VyF'
-
-// Make sure we also generate the accessor with a numeric literal.
-// CHECK-LABEL: sil shared @$sSo25WithConstexprStaticMemberV13definedInlines5Int32VvgZ : $@convention(method) (@thin WithConstexprStaticMember.Type) -> Int32
-// CHECK: [[IL:%.*]] = integer_literal $Builtin.Int32, 139
-// CHECK: [[OUT:%.*]] = struct $Int32 ([[IL]] : $Builtin.Int32)
-// CHECK: return [[OUT]] : $Int32
-// CHECK-LABEL: end sil function '$sSo25WithConstexprStaticMemberV13definedInlines5Int32VvgZ'
-
-func readConstexprStaticMember() -> CInt {
-  return WithConstexprStaticMember.definedInline
-}
+}

test/Interop/Cxx/static/static-var-irgen.swift

@@ -4,14 +4,9 @@ import StaticVar
 
 public func initStaticVars() -> CInt {
   return staticVar + staticVarInit + staticVarInlineInit + staticConst + staticConstInit
-    + staticConstInlineInit + staticConstexpr + staticNonTrivial.val + staticConstNonTrivial.val
-    + staticConstexprNonTrivial.val
+    + staticConstInlineInit + staticNonTrivial.val + staticConstNonTrivial.val
 }
 
-// Constexpr vars should be inlined and removed.
-// CHECK-NOT: ?staticConstexpr
-// CHECK-NOT: _ZL15staticConstexpr
-
 // CHECK: @{{_ZL9staticVar|staticVar}} = internal global i32 2, align 4
 // CHECK: @{{_ZL13staticVarInit|staticVarInit}} = internal global i32 0, align 4
 // CHECK: @{{_ZL19staticVarInlineInit|staticVarInlineInit}} = internal global i32 0, align 4
@@ -20,7 +15,6 @@ public func initStaticVars() -> CInt {
 // CHECK: @{{_ZL21staticConstInlineInit|staticConstInlineInit}} = internal global i32 0, align 4
 // CHECK: @{{_ZL16staticNonTrivial|staticNonTrivial}} = internal global %class.NonTrivial zeroinitializer, align 4
 // CHECK: @{{_ZL21staticConstNonTrivial|staticConstNonTrivial}} = internal global %class.NonTrivial zeroinitializer, align 4
-// CHECK: @{{_ZL25staticConstexprNonTrivial|staticConstexprNonTrivial}} = internal constant %class.NonTrivial { i32 8192 }, align 4
 
 // CHECK: define internal void @{{__cxx_global_var_init|"\?\?__EstaticVarInit@@YAXXZ"}}()
 // CHECK: %call = call i32 @{{_Z13makeStaticVarv|"\?makeStaticVar@@YAHXZ"}}()

test/Interop/Cxx/static/static-var-silgen.swift

@@ -4,13 +4,9 @@ import StaticVar
 
 func initStaticVars() -> CInt {
   return staticVar + staticVarInit + staticVarInlineInit + staticConst + staticConstInit
-    + staticConstInlineInit + staticConstexpr + staticNonTrivial.val + staticConstNonTrivial.val
-    + staticConstexprNonTrivial.val
+    + staticConstInlineInit + staticNonTrivial.val + staticConstNonTrivial.val
 }
 
-// Constexpr globals should be inlined and removed.
-// CHECK-NOT: sil_global public_external [let] @staticConstexpr : $Int32
-
 // CHECK: // clang name: staticVar
 // CHECK: sil_global public_external @staticVar : $Int32
 // CHECK: // clang name: staticVarInit
@@ -27,8 +23,6 @@ func initStaticVars() -> CInt {
 // CHECK: sil_global public_external @staticNonTrivial : $NonTrivial
 // CHECK: // clang name: staticConstNonTrivial
 // CHECK: sil_global public_external [let] @staticConstNonTrivial : $NonTrivial
-// CHECK: // clang name: staticConstexprNonTrivial
-// CHECK: sil_global public_external [let] @staticConstexprNonTrivial : $NonTrivial
 
 func readStaticVar() -> CInt {
   return staticVar

test/Interop/Cxx/static/static-var.swift

@@ -47,10 +47,6 @@ StaticVarTestSuite.test("static-const-int-init") {
   expectEqual(128, staticConstInit)
 }
 
-StaticVarTestSuite.test("static-constexpr-int") {
-  expectEqual(32, staticConstexpr)
-}
-
 StaticVarTestSuite.test("static-non-trivial") {
   expectEqual(1024, staticNonTrivial.val)
 }
@@ -75,8 +71,4 @@ StaticVarTestSuite.test("static-const-non-trivial") {
   expectEqual(2048, staticConstNonTrivial.val)
 }
 
-StaticVarTestSuite.test("static-constexpr-non-trivial") {
-  expectEqual(8192, staticConstexprNonTrivial.val)
-}
-
 runAllTests()