Add ValueGenerics experimental feature

Author: Azoy

include/swift/AST/DiagnosticsSema.def

@@ -8024,6 +8024,8 @@ ERROR(value_generic_unexpected,none,
       "using value generic %0 here is not allowed", (Type))
 ERROR(missing_value_generic_type,none,
       "value generic %0 must have an explicit value type declared", (Identifier))
+ERROR(value_generics_missing_feature,none,
+      "value generics require '-enable-experimental-feature ValueGenerics'", ())
 
 #define UNDEFINE_DIAGNOSTIC_MACROS
 #include "DefineDiagnosticMacros.h"

include/swift/Basic/Features.def

@@ -408,6 +408,9 @@ SUPPRESSIBLE_EXPERIMENTAL_FEATURE(AllowUnsafeAttribute, true)
 /// Warn on use of unsafe constructs.
 EXPERIMENTAL_FEATURE(WarnUnsafe, true)
 
+// Enable values in generic signatures, e.g. <let N: Int>
+EXPERIMENTAL_FEATURE(ValueGenerics, true)
+
 #undef EXPERIMENTAL_FEATURE_EXCLUDED_FROM_MODULE_INTERFACE
 #undef EXPERIMENTAL_FEATURE
 #undef UPCOMING_FEATURE

lib/AST/FeatureSet.cpp

@@ -14,6 +14,7 @@
 
 #include "swift/AST/Decl.h"
 #include "swift/AST/ExistentialLayout.h"
+#include "swift/AST/GenericParamList.h"
 #include "swift/AST/NameLookup.h"
 #include "swift/AST/ParameterList.h"
 #include "swift/AST/Pattern.h"
@@ -232,6 +233,22 @@ static bool usesFeatureAllowUnsafeAttribute(Decl *decl) {
 
 UNINTERESTING_FEATURE(WarnUnsafe)
 
+static bool usesFeatureValueGenerics(Decl *decl) {
+  auto genericContext = decl->getAsGenericContext();
+
+  if (!genericContext || !genericContext->getGenericParams())
+    return false;
+
+  for (auto param : genericContext->getGenericParams()->getParams()) {
+    if (param->isValue())
+      return true;
+
+    continue;
+  }
+
+  return false;
+}
+
 // ----------------------------------------------------------------------------
 // MARK: - FeatureSet
 // ----------------------------------------------------------------------------

lib/AST/RequirementMachine/RequirementMachineRequests.cpp

@@ -825,6 +825,10 @@ InferredGenericSignatureRequest::evaluate(
              "Parsed an empty generic parameter list?");
 
       for (auto *gpDecl : *gpList) {
+        if (gpDecl->isValue() &&
+            !gpDecl->getASTContext().LangOpts.hasFeature(Feature::ValueGenerics))
+          gpDecl->diagnose(diag::value_generics_missing_feature);
+
         auto *gpType = gpDecl->getDeclaredInterfaceType()
                              ->castTo<GenericTypeParamType>();
         genericParams.push_back(gpType);

lib/Sema/TypeCheckType.cpp

@@ -761,7 +761,7 @@ namespace {
       // parameter doesn't declare a value type and we're going to diagnose it
       // later.
       if (!paramType->getValueType() || !secondType->getValueType())
-        return false;
+        return true;
 
       // Otherwise, these are both value parameters and check that both their
       // value types are the same.

test/ASTGen/decls.swift

@@ -1,15 +1,15 @@
 
 // RUN: %empty-directory(%t)
-// RUN: %target-swift-frontend %s -dump-parse -disable-availability-checking -enable-experimental-move-only -enable-experimental-feature ParserASTGen > %t/astgen.ast.raw
-// RUN: %target-swift-frontend %s -dump-parse -disable-availability-checking -enable-experimental-move-only > %t/cpp-parser.ast.raw
+// RUN: %target-swift-frontend %s -dump-parse -disable-availability-checking -enable-experimental-move-only -enable-experimental-feature ParserASTGen -enable-experimental-feature ValueGenerics > %t/astgen.ast.raw
+// RUN: %target-swift-frontend %s -dump-parse -disable-availability-checking -enable-experimental-move-only -enable-experimental-feature ValueGenerics > %t/cpp-parser.ast.raw
 
 // Filter out any addresses in the dump, since they can differ.
 // RUN: sed -E 's#0x[0-9a-fA-F]+##g' %t/cpp-parser.ast.raw > %t/cpp-parser.ast
 // RUN: sed -E 's#0x[0-9a-fA-F]+##g' %t/astgen.ast.raw > %t/astgen.ast
 
 // RUN: %diff -u %t/astgen.ast %t/cpp-parser.ast
 
-// RUN: %target-run-simple-swift(-Xfrontend -disable-availability-checking -enable-experimental-feature SwiftParser -enable-experimental-feature ParserASTGen)
+// RUN: %target-run-simple-swift(-Xfrontend -disable-availability-checking -enable-experimental-feature SwiftParser -enable-experimental-feature ParserASTGen -enable-experimental-feature ValueGenerics)
 
 // REQUIRES: executable_test
 // REQUIRES: swift_swift_parser

test/IRGen/raw_layout.swift

@@ -1,6 +1,6 @@
 // RUN: %empty-directory(%t)
 // RUN: %{python} %utils/chex.py < %s > %t/raw_layout.sil
-// RUN: %target-swift-frontend -enable-experimental-feature RawLayout -emit-ir -disable-availability-checking -I %S/Inputs -cxx-interoperability-mode=upcoming-swift %t/raw_layout.sil | %FileCheck %t/raw_layout.sil --check-prefix=CHECK --check-prefix=CHECK-%target-ptrsize
+// RUN: %target-swift-frontend -enable-experimental-feature RawLayout -enable-experimental-feature ValueGenerics -emit-ir -disable-availability-checking -I %S/Inputs -cxx-interoperability-mode=upcoming-swift %t/raw_layout.sil | %FileCheck %t/raw_layout.sil --check-prefix=CHECK --check-prefix=CHECK-%target-ptrsize
 
 import Builtin
 import Swift
@@ -428,7 +428,7 @@ entry(%0 : $*Cell<T>):
 
 // CHECK-LABEL: define {{.*}} void @"$s10raw_layout18ConcreteMoveAsLikeVwxx"(ptr {{.*}} %object, ptr %ConcreteMoveAsLike)
 // CHECK:         [[OBJ_CELL:%.*]] = getelementptr inbounds %T10raw_layout18ConcreteMoveAsLikeV, ptr %object, i32 0, i32 0
-// CHECK:         {{invoke void|invoke ptr|call void}} @{{.*}}(ptr [[OBJ_CELL]])
+// CHECK:         {{invoke void|invoke ptr|call void|call ptr}} @{{.*}}(ptr [[OBJ_CELL]])
 
 //===----------------------------------------------------------------------===//
 // ConcreteMoveAsLike initializeWithTake
@@ -555,7 +555,7 @@ entry(%0 : $*Cell<T>):
 // CHECK:         [[NEW_I:%.*]] = add {{i64|i32}} [[I]], 1
 // CHECK:         store {{i64|i32}} [[NEW_I]], ptr [[I_ALLOCA]]
 // CHECK:         [[OBJECT:%.*]] = getelementptr inbounds %TSo24NonBitwiseTakableCXXTypeV, ptr [[OBJ_VECTOR]], {{i64|i32}} [[I]]
-// CHECK-NEXT:    {{invoke void|invoke ptr|call void}} @{{.*}}(ptr [[OBJECT]])
+// CHECK-NEXT:    {{invoke void|invoke ptr|call void|call ptr}} @{{.*}}(ptr [[OBJECT]])
 
 // This may or may not be in the loop_br
 // CHECK:         [[EQ_CMP:%.*]] = icmp eq {{i64|i32}} [[NEW_I]], 2
@@ -747,7 +747,7 @@ entry(%0 : $*Cell<T>):
 // CHECK:         [[NEW_I:%.*]] = add {{i64|i32}} [[I]], 1
 // CHECK:         store {{i64|i32}} [[NEW_I]], ptr [[I_ALLOCA]]
 // CHECK:         [[OBJECT:%.*]] = getelementptr inbounds %TSo24NonBitwiseTakableCXXTypeV, ptr [[OBJ_VECTOR]], {{i64|i32}} [[I]]
-// CHECK-NEXT:    {{invoke void|invoke ptr|call void}} @{{.*}}(ptr [[OBJECT]])
+// CHECK-NEXT:    {{invoke void|invoke ptr|call void|call ptr}} @{{.*}}(ptr [[OBJECT]])
 
 // This may or may not be in the loop_br
 // CHECK:         [[EQ_CMP:%.*]] = icmp eq {{i64|i32}} [[NEW_I]], 4

test/Interpreter/value_generics.swift

@@ -1,4 +1,4 @@
-// RUN: %target-run-simple-swift | %FileCheck %s
+// RUN: %target-run-simple-swift(-enable-experimental-feature ValueGenerics) | %FileCheck %s
 
 // REQUIRES: executable_test
 

test/ModuleInterface/value_generics.swift

@@ -1,5 +1,5 @@
 // RUN: %empty-directory(%t)
-// RUN: %target-swift-emit-module-interface(%t.swiftinterface) %s -module-name ValueGeneric
+// RUN: %target-swift-emit-module-interface(%t.swiftinterface) %s -module-name ValueGeneric -enable-experimental-feature ValueGenerics
 // RUN: %target-swift-typecheck-module-from-interface(%t.swiftinterface) -module-name ValueGeneric
 // RUN: %FileCheck %s < %t.swiftinterface
 

test/SIL/Parser/basic2.sil

@@ -1,4 +1,4 @@
-// RUN: %target-sil-opt %s | %target-sil-opt | %FileCheck %s
+// RUN: %target-sil-opt %s -enable-experimental-feature ValueGenerics | %target-sil-opt -enable-experimental-feature ValueGenerics | %FileCheck %s
 
 import Builtin
 import Swift