Merge pull request #3813 from swiftwasm/main

Author: MaxDesiatov

docs/SIL.rst

@@ -5205,6 +5205,36 @@ independent of the operand. In terms of specific types:
 In ownership qualified functions, a ``copy_value`` produces a +1 value that must
 be consumed at most once along any path through the program.
 
+explicit_copy_value
+```````````````````
+
+::
+
+   sil-instruction ::= 'explicit_copy_value' sil-operand
+
+   %1 = explicit_copy_value %0 : $A
+
+Performs a copy of a loadable value as if by the value's type lowering and
+returns the copy. The returned copy semantically is a value that is completely
+independent of the operand. In terms of specific types:
+
+1. For trivial types, this is equivalent to just propagating through the trivial
+   value.
+2. For reference types, this is equivalent to performing a ``strong_retain``
+   operation and returning the reference.
+3. For ``@unowned`` types, this is equivalent to performing an
+   ``unowned_retain`` and returning the operand.
+4. For aggregate types, this is equivalent to recursively performing a
+   ``copy_value`` on its components, forming a new aggregate from the copied
+   components, and then returning the new aggregate.
+
+In ownership qualified functions, a ``explicit_copy_value`` produces a +1 value
+that must be consumed at most once along any path through the program.
+
+When move only variable checking is performed, ``explicit_copy_value`` is
+treated as an explicit copy asked for by the user that should not be rewritten
+and should be treated as a non-consuming use.
+
 move_value
 ``````````
 

include/swift/AST/Builtins.def

@@ -790,6 +790,24 @@ BUILTIN_MISC_OPERATION(DestroyTaskGroup,
 /// the SILVerifier.
 BUILTIN_MISC_OPERATION(Move, "move", "", Special)
 
+/// A builtin that can only be called from a transparent generic function. Takes
+/// two operands, the first operand the result address, the second operand the
+/// input address. Transforms into
+///
+///   %input = load [take] %inputAddr
+///   %result = explicit_copy_value %input
+///   store %result to [init] %resultAddr
+///   store %input to [init] %inputAddr
+///
+/// transparently inlined into a caller that has the generic of the callee
+/// specialized into a loadable type. If the transparent inlining does not
+/// specialize the type (due to being inlined into a non-generic context, the
+/// SILVerifier will abort).
+///
+/// Illegal to call except for in Swift._copy in the stdlib. This is enforced by
+/// the SILVerifier.
+BUILTIN_MISC_OPERATION(Copy, "copy", "", Special)
+
 // BUILTIN_MISC_OPERATION_WITH_SILGEN - Miscellaneous operations that are
 // specially emitted during SIL generation.
 //

include/swift/AST/DiagnosticsSIL.def

@@ -718,6 +718,10 @@ NOTE(capturepromotion_variable_defined_here,none,
 ERROR(move_operator_used_on_generic_or_existential_value, none,
       "move() used on a generic or existential value", ())
 
+// copy operator used on generic or evalue
+ERROR(copy_operator_used_on_generic_or_existential_value, none,
+      "copy() used on a generic or existential value", ())
+
 // noimplicitcopy on generic or existential binding
 ERROR(noimplicitcopy_used_on_generic_or_existential, none,
       "@_noImplicitCopy can not be used on a generic or existential typed "

include/swift/AST/GenericSignature.h

@@ -114,7 +114,9 @@ class GenericSignature {
 
 public:
   /// Create a new generic signature with the given type parameters and
-  /// requirements.
+  /// requirements. The requirements must already be minimal and canonical;
+  /// to build a signature from an arbitrary set of requirements, use
+  /// swift::buildGenericSignature() instead.
   static GenericSignature get(ArrayRef<GenericTypeParamType *> params,
                               ArrayRef<Requirement> requirements,
                               bool isKnownCanonical = false);
@@ -494,6 +496,31 @@ int compareAssociatedTypes(AssociatedTypeDecl *assocType1,
 
 int compareDependentTypes(Type type1, Type type2);
 
+/// Verify the correctness of the given generic signature.
+///
+/// This routine will test that the given generic signature is both minimal
+/// and canonical, emitting errors if it is not.
+void validateGenericSignature(ASTContext &context,
+                              GenericSignature sig);
+
+/// Verify all of the generic signatures in the given module.
+void validateGenericSignaturesInModule(ModuleDecl *module);
+
+/// Build a generic signature from the given requirements, which are not
+/// required to be minimal or canonical, and may contain unresolved
+/// DependentMemberTypes.
+///
+/// If \p baseSignature is non-null, the new parameters and requirements
+/// are added on; existing requirements of the base signature might become
+/// redundant.
+///
+/// If \p baseSignature is null, build a new signature from scratch.
+GenericSignature buildGenericSignature(
+    ASTContext &ctx,
+    GenericSignature baseSignature,
+    SmallVector<GenericTypeParamType *, 2> addedParameters,
+    SmallVector<Requirement, 2> addedRequirements);
+
 } // end namespace swift
 
 namespace llvm {

include/swift/AST/SemanticAttrs.def

@@ -114,6 +114,7 @@ SEMANTICS_ATTR(FORCE_EMIT_OPT_REMARK_PREFIX, "optremark")
 SEMANTICS_ATTR(OBJC_FORBID_ASSOCIATED_OBJECTS, "objc.forbidAssociatedObjects")
 
 SEMANTICS_ATTR(LIFETIMEMANAGEMENT_MOVE, "lifetimemanagement.move")
+SEMANTICS_ATTR(LIFETIMEMANAGEMENT_COPY, "lifetimemanagement.copy")
 
 SEMANTICS_ATTR(NO_PERFORMANCE_ANALYSIS, "no_performance_analysis")
 

include/swift/AST/TypeCheckRequests.h

@@ -1411,11 +1411,17 @@ class ClassAncestryFlagsRequest :
 
 void simple_display(llvm::raw_ostream &out, AncestryFlags value);
 
+/// AbstractGenericSignatureRequest and InferredGenericSignatureRequest
+/// return this type, which stores a GenericSignature together with a bit
+/// indicating if there were any errors detected in the original
+/// requirements.
+using GenericSignatureWithError = llvm::PointerIntPair<GenericSignature, 1>;
+
 class AbstractGenericSignatureRequest :
     public SimpleRequest<AbstractGenericSignatureRequest,
-                         GenericSignature (const GenericSignatureImpl *,
-                                           SmallVector<GenericTypeParamType *, 2>,
-                                           SmallVector<Requirement, 2>),
+                         GenericSignatureWithError (const GenericSignatureImpl *,
+                                                    SmallVector<GenericTypeParamType *, 2>,
+                                                    SmallVector<Requirement, 2>),
                          RequestFlags::Cached> {
 public:
   using SimpleRequest::SimpleRequest;
@@ -1424,7 +1430,7 @@ class AbstractGenericSignatureRequest :
   friend SimpleRequest;
 
   // Evaluation.
-  GenericSignature
+  GenericSignatureWithError
   evaluate(Evaluator &evaluator,
            const GenericSignatureImpl *baseSignature,
            SmallVector<GenericTypeParamType *, 2> addedParameters,
@@ -1442,13 +1448,13 @@ class AbstractGenericSignatureRequest :
 
 class InferredGenericSignatureRequest :
     public SimpleRequest<InferredGenericSignatureRequest,
-                         GenericSignature (ModuleDecl *,
-                                           const GenericSignatureImpl *,
-                                           GenericParamList *,
-                                           WhereClauseOwner,
-                                           SmallVector<Requirement, 2>,
-                                           SmallVector<TypeLoc, 2>,
-                                           bool),
+                         GenericSignatureWithError (ModuleDecl *,
+                                                    const GenericSignatureImpl *,
+                                                    GenericParamList *,
+                                                    WhereClauseOwner,
+                                                    SmallVector<Requirement, 2>,
+                                                    SmallVector<TypeLoc, 2>,
+                                                    bool),
                          RequestFlags::Cached> {
 public:
   using SimpleRequest::SimpleRequest;
@@ -1457,7 +1463,7 @@ class InferredGenericSignatureRequest :
   friend SimpleRequest;
 
   // Evaluation.
-  GenericSignature
+  GenericSignatureWithError
   evaluate(Evaluator &evaluator,
            ModuleDecl *parentModule,
            const GenericSignatureImpl *baseSignature,

include/swift/AST/TypeCheckerTypeIDZone.def

@@ -16,9 +16,9 @@
 //===----------------------------------------------------------------------===//
 
 SWIFT_REQUEST(TypeChecker, AbstractGenericSignatureRequest,
-              GenericSignature (const GenericSignatureImpl *,
-                                SmallVector<GenericTypeParamType *, 2>,
-                                SmallVector<Requirement, 2>),
+              GenericSignatureWithError (const GenericSignatureImpl *,
+                                         SmallVector<GenericTypeParamType *, 2>,
+                                         SmallVector<Requirement, 2>),
               Cached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, ApplyAccessNoteRequest,
               evaluator::SideEffect(ValueDecl *), Cached, NoLocationInfo)
@@ -131,12 +131,12 @@ SWIFT_REQUEST(TypeChecker, HasImplementationOnlyImportsRequest,
 SWIFT_REQUEST(TypeChecker, ModuleLibraryLevelRequest,
               LibraryLevel(ModuleDecl *), Cached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, InferredGenericSignatureRequest,
-              GenericSignature (ModuleDecl *,
-                                const GenericSignatureImpl *,
-                                GenericParamList *,
-                                WhereClauseOwner,
-                                SmallVector<Requirement, 2>,
-                                SmallVector<TypeLoc, 2>, bool),
+              GenericSignatureWithError (ModuleDecl *,
+                                         const GenericSignatureImpl *,
+                                         GenericParamList *,
+                                         WhereClauseOwner,
+                                         SmallVector<Requirement, 2>,
+                                         SmallVector<TypeLoc, 2>, bool),
               Cached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, DistributedModuleIsAvailableRequest,
               bool(ModuleDecl *), Cached, NoLocationInfo)

include/swift/Basic/Features.def

@@ -55,5 +55,6 @@ LANGUAGE_FEATURE(BuiltinBuildExecutor, 0, "Executor-building builtins", true)
 LANGUAGE_FEATURE(BuiltinBuildMainExecutor, 0, "MainActor executor building builtin", true)
 LANGUAGE_FEATURE(BuiltinCreateAsyncTaskInGroup, 0, "MainActor executor building builtin", true)
 LANGUAGE_FEATURE(BuiltinMove, 0, "Builtin.move()", true)
+LANGUAGE_FEATURE(BuiltinCopy, 0, "Builtin.copy()", true)
 
 #undef LANGUAGE_FEATURE

include/swift/SIL/SILBuilder.h

@@ -1237,6 +1237,15 @@ class SILBuilder {
                       CopyValueInst(getSILDebugLocation(Loc), operand));
   }
 
+  ExplicitCopyValueInst *createExplicitCopyValue(SILLocation Loc,
+                                                 SILValue operand) {
+    assert(!operand->getType().isTrivial(getFunction()) &&
+           "Should not be passing trivial values to this api. Use instead "
+           "emitCopyValueOperation");
+    return insert(new (getModule())
+                      ExplicitCopyValueInst(getSILDebugLocation(Loc), operand));
+  }
+
   DestroyValueInst *createDestroyValue(SILLocation Loc, SILValue operand,
                                        bool poisonRefs = false) {
     assert(isLoadableOrOpaque(operand->getType()));

include/swift/SIL/SILCloner.h

@@ -1713,6 +1713,21 @@ void SILCloner<ImplClass>::visitCopyValueInst(CopyValueInst *Inst) {
                                          getOpValue(Inst->getOperand())));
 }
 
+template <typename ImplClass>
+void SILCloner<ImplClass>::visitExplicitCopyValueInst(
+    ExplicitCopyValueInst *Inst) {
+  getBuilder().setCurrentDebugScope(getOpScope(Inst->getDebugScope()));
+  if (!getBuilder().hasOwnership()) {
+    SILValue newValue = getBuilder().emitCopyValueOperation(
+        getOpLocation(Inst->getLoc()), getOpValue(Inst->getOperand()));
+    return recordFoldedValue(Inst, newValue);
+  }
+
+  recordClonedInstruction(
+      Inst, getBuilder().createExplicitCopyValue(
+                getOpLocation(Inst->getLoc()), getOpValue(Inst->getOperand())));
+}
+
 template <typename ImplClass>
 void SILCloner<ImplClass>::visitMoveValueInst(MoveValueInst *Inst) {
   getBuilder().setCurrentDebugScope(getOpScope(Inst->getDebugScope()));