[NFC] Pass SIL-specific type resolution state abstractly into Sema

This is in preparation for parsing pack element archetypes.

Author: rjmccall

include/swift/AST/DiagnosticsSema.def

@@ -5302,6 +5302,8 @@ NOTE(overridden_required_initializer_here,none,
 // Functions
 ERROR(attribute_requires_function_type,none,
       "@%0 attribute only applies to function types", (StringRef))
+ERROR(generic_function_type,none,
+      "function values cannot be generic", ())
 ERROR(unsupported_convention,none,
       "convention '%0' not supported", (StringRef))
 ERROR(unreferenced_generic_parameter,NoUsage,

include/swift/AST/TypeCheckRequests.h

@@ -3291,8 +3291,7 @@ class ModuleLibraryLevelRequest
 
 class ResolveTypeRequest
     : public SimpleRequest<ResolveTypeRequest,
-                           Type(const TypeResolution *, TypeRepr *,
-                                GenericParamList *),
+                           Type(const TypeResolution *, TypeRepr *),
                            RequestFlags::Uncached> {
 public:
   using SimpleRequest::SimpleRequest;
@@ -3301,12 +3300,15 @@ class ResolveTypeRequest
   // Cycle handling.
   void noteCycleStep(DiagnosticEngine &diags) const;
 
+  static Type evaluate(const TypeResolution &resolution,
+                       TypeRepr *repr);
+
 private:
   friend SimpleRequest;
 
   // Evaluation.
   Type evaluate(Evaluator &evaluator, const TypeResolution *resolution,
-                TypeRepr *repr, GenericParamList *silParams) const;
+                TypeRepr *repr) const;
 };
 
 void simple_display(llvm::raw_ostream &out, const TypeResolution *resolution);

include/swift/Sema/SILTypeResolutionContext.h

@@ -0,0 +1,34 @@
+//===--- SILTypeResolutionContext.h -----------------------------*- C++ -*-===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2022 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SWIFT_SEMA_SILTYPERESOLUTIONCONTEXT_H
+#define SWIFT_SEMA_SILTYPERESOLUTIONCONTEXT_H
+
+namespace swift {
+class GenericParamList;
+
+class SILTypeResolutionContext {
+public:
+  /// Are we requesting a SIL type?
+  bool IsSILType;
+
+  /// Look up types in the given parameter list.
+  GenericParamList *GenericParams;
+
+  SILTypeResolutionContext(bool isSILType,
+                           GenericParamList *genericParams)
+    : IsSILType(isSILType), GenericParams(genericParams) {}
+};
+
+}
+
+#endif

include/swift/Subsystems.h

@@ -64,6 +64,7 @@ namespace swift {
   class SerializationOptions;
   class SILOptions;
   class SILModule;
+  class SILTypeResolutionContext;
   class SourceFile;
   enum class SourceFileKind;
   class SourceManager;
@@ -163,10 +164,9 @@ namespace swift {
   /// code completion).
   ///
   /// \returns A well-formed type on success, or an \c ErrorType.
-  Type performTypeResolution(TypeRepr *TyR, ASTContext &Ctx, bool isSILMode,
-                             bool isSILType,
+  Type performTypeResolution(TypeRepr *TyR, ASTContext &Ctx,
                              GenericSignature GenericSig,
-                             GenericParamList *GenericParams,
+                             SILTypeResolutionContext *SILContext,
                              DeclContext *DC, bool ProduceDiagnostics = true);
 
   /// Expose TypeChecker's handling of GenericParamList to SIL parsing.

lib/IDE/CodeCompletion.cpp

@@ -200,10 +200,8 @@ class CodeCompletionCallbacksImpl : public IDEInspectionCallbacks {
 
     const auto ty = swift::performTypeResolution(
         ParsedTypeLoc.getTypeRepr(), P.Context,
-        /*isSILMode=*/false,
-        /*isSILType=*/false,
         CurDeclContext->getGenericSignatureOfContext(),
-        /*GenericParams=*/nullptr,
+        /*SILContext=*/nullptr,
         CurDeclContext,
         /*ProduceDiagnostics=*/false);
     if (!ty->hasError()) {

lib/IDE/ExprContextAnalysis.cpp

@@ -254,8 +254,7 @@ void swift::ide::collectPossibleReturnTypesFromContext(
         } else {
           const auto type = swift::performTypeResolution(
               CE->getExplicitResultTypeRepr(), DC->getASTContext(),
-              /*isSILMode=*/false, /*isSILType=*/false,
-              DC->getGenericSignatureOfContext(), /*GenericParams=*/nullptr,
+              DC->getGenericSignatureOfContext(), /*SILContext=*/nullptr,
               const_cast<DeclContext *>(DC), /*diagnostics=*/false);
 
           if (!type->hasError()) {

lib/SIL/Parser/ParseSIL.cpp

@@ -27,6 +27,7 @@
 #include "swift/Parse/Lexer.h"
 #include "swift/Parse/ParseSILSupport.h"
 #include "swift/Parse/Parser.h"
+#include "swift/Sema/SILTypeResolutionContext.h"
 #include "swift/SIL/AbstractionPattern.h"
 #include "swift/SIL/InstructionUtils.h"
 #include "swift/SIL/SILArgument.h"
@@ -131,6 +132,7 @@ namespace {
 } // namespace
 
 namespace swift {
+  /// The parser for an individual SIL function.
   class SILParser {
     friend SILParserState;
   public:
@@ -1255,10 +1257,10 @@ Type SILParser::performTypeResolution(TypeRepr *TyR, bool IsSILType,
   if (!GenericSig)
     GenericSig = ContextGenericSig;
 
-  return swift::performTypeResolution(TyR, P.Context,
-                                      /*isSILMode=*/true, IsSILType,
-                                      GenericSig, GenericParams,
-                                      &P.SF);
+  SILTypeResolutionContext SILContext(IsSILType, GenericParams);
+
+  return swift::performTypeResolution(TyR, P.Context, GenericSig,
+                                      &SILContext, &P.SF);
 }
 
 /// Find the top-level ValueDecl or Module given a name.
@@ -7590,12 +7592,11 @@ static bool parseSILWitnessTableEntry(
       if (TyR.isNull())
         return true;
 
+      SILTypeResolutionContext silContext(/*isSILType=*/false,
+                                          witnessParams);
       auto Ty =
           swift::performTypeResolution(TyR.get(), P.Context,
-                                       /*isSILMode=*/false,
-                                       /*isSILType=*/false,
-                                       witnessSig,
-                                       witnessParams,
+                                       witnessSig, &silContext,
                                        &P.SF);
       if (witnessSig) {
         Ty = witnessSig.getGenericEnvironment()->mapTypeIntoContext(Ty);
@@ -7655,11 +7656,11 @@ static bool parseSILWitnessTableEntry(
     if (TyR.isNull())
       return true;
 
+    SILTypeResolutionContext silContext(/*isSILType=*/false,
+                                        witnessParams);
     auto Ty =
         swift::performTypeResolution(TyR.get(), P.Context,
-                                     /*isSILMode=*/false,
-                                     /*isSILType=*/false,
-                                     witnessSig, witnessParams,
+                                     witnessSig, &silContext,
                                      &P.SF);
     if (witnessSig) {
       Ty = witnessSig.getGenericEnvironment()->mapTypeIntoContext(Ty);

lib/SIL/Parser/SILParserState.h

@@ -25,6 +25,9 @@ namespace swift {
 class Parser;
 class SILModule;
 
+/// The global state of the SIL parser that the ordinary parser needs to
+/// maintain while parsing a SIL file.  Local state, like the value map of
+/// a SIL function, does not need to be kept here.
 class SILParserState : public SILParserStateBase {
 public:
   explicit SILParserState(SILModule &M) : M(M) {}