[TypeChecker] Teach declaration type-checking about LeaveClosureBodyUnchecked flag

Propagate `LeaveClosureBodyUnchecked` flag from `typeCheckASTNodeAtLoc`
down to declaration checker to skip checking closures associated with
pattern binding entry initializers. This is no-op until multi-statement
inference becomes enabled by default.

Author: xedin

lib/Sema/TypeCheckConstraints.cpp

@@ -431,9 +431,11 @@ Type TypeChecker::typeCheckParameterDefault(Expr *&defaultValue,
                                              : CTP_DefaultParameter});
 }
 
-bool TypeChecker::typeCheckBinding(
-    Pattern *&pattern, Expr *&initializer, DeclContext *DC,
-    Type patternType, PatternBindingDecl *PBD, unsigned patternNumber) {
+bool TypeChecker::typeCheckBinding(Pattern *&pattern, Expr *&initializer,
+                                   DeclContext *DC, Type patternType,
+                                   PatternBindingDecl *PBD,
+                                   unsigned patternNumber,
+                                   TypeCheckExprOptions options) {
   SolutionApplicationTarget target =
     PBD ? SolutionApplicationTarget::forInitialization(
             initializer, DC, patternType, PBD, patternNumber,
@@ -442,7 +444,6 @@ bool TypeChecker::typeCheckBinding(
             initializer, DC, patternType, pattern,
             /*bindPatternVarsOneWay=*/false);
 
-  auto options = TypeCheckExprOptions();
   if (DC->getASTContext().LangOpts.CheckAPIAvailabilityOnly &&
       PBD && !DC->getAsDecl()) {
     // Skip checking the initializer for non-public decls when
@@ -491,7 +492,8 @@ bool TypeChecker::typeCheckBinding(
 
 bool TypeChecker::typeCheckPatternBinding(PatternBindingDecl *PBD,
                                           unsigned patternNumber,
-                                          Type patternType) {
+                                          Type patternType,
+                                          TypeCheckExprOptions options) {
   Pattern *pattern = PBD->getPattern(patternNumber);
   Expr *init = PBD->getInit(patternNumber);
 
@@ -520,8 +522,8 @@ bool TypeChecker::typeCheckPatternBinding(PatternBindingDecl *PBD,
     }
   }
 
-  bool hadError = TypeChecker::typeCheckBinding(
-      pattern, init, DC, patternType, PBD, patternNumber);
+  bool hadError = TypeChecker::typeCheckBinding(pattern, init, DC, patternType,
+                                                PBD, patternNumber, options);
   if (!init) {
     PBD->setInvalid();
     return true;

lib/Sema/TypeCheckDeclPrimary.cpp

@@ -1670,7 +1670,12 @@ class DeclChecker : public DeclVisitor<DeclChecker> {
   ASTContext &Ctx;
   SourceFile *SF;
 
-  explicit DeclChecker(ASTContext &ctx, SourceFile *SF) : Ctx(ctx), SF(SF) {}
+  bool LeaveClosureBodiesUnchecked;
+
+  explicit DeclChecker(ASTContext &ctx, SourceFile *SF,
+                       bool LeaveClosureBodiesUnchecked = false)
+      : Ctx(ctx), SF(SF),
+        LeaveClosureBodiesUnchecked(LeaveClosureBodiesUnchecked) {}
 
   ASTContext &getASTContext() const { return Ctx; }
   void addDelayedFunction(AbstractFunctionDecl *AFD) {
@@ -2044,7 +2049,13 @@ class DeclChecker : public DeclVisitor<DeclChecker> {
         continue;
 
       if (!PBD->isInitializerChecked(i)) {
-        TypeChecker::typeCheckPatternBinding(PBD, i);
+        TypeCheckExprOptions options;
+
+        if (LeaveClosureBodiesUnchecked)
+          options |= TypeCheckExprFlags::LeaveClosureBodyUnchecked;
+
+        TypeChecker::typeCheckPatternBinding(PBD, i, /*patternType=*/Type(),
+                                             options);
       }
 
       if (!PBD->isInvalid()) {
@@ -3164,9 +3175,9 @@ class DeclChecker : public DeclVisitor<DeclChecker> {
 };
 } // end anonymous namespace
 
-void TypeChecker::typeCheckDecl(Decl *D) {
+void TypeChecker::typeCheckDecl(Decl *D, bool LeaveClosureBodiesUnchecked) {
   auto *SF = D->getDeclContext()->getParentSourceFile();
-  DeclChecker(D->getASTContext(), SF).visit(D);
+  DeclChecker(D->getASTContext(), SF, LeaveClosureBodiesUnchecked).visit(D);
 }
 
 void TypeChecker::checkParameterList(ParameterList *params,

lib/Sema/TypeCheckStmt.cpp

@@ -1514,7 +1514,7 @@ void StmtChecker::typeCheckASTNode(ASTNode &node) {
 
   // Type check the declaration.
   if (auto *D = node.dyn_cast<Decl *>()) {
-    TypeChecker::typeCheckDecl(D);
+    TypeChecker::typeCheckDecl(D, LeaveBraceStmtBodyUnchecked);
     return;
   }
 

lib/Sema/TypeChecker.cpp

@@ -445,15 +445,20 @@ swift::handleSILGenericParams(GenericParamList *genericParams,
 }
 
 void swift::typeCheckPatternBinding(PatternBindingDecl *PBD,
-                                    unsigned bindingIndex) {
+                                    unsigned bindingIndex,
+                                    bool leaveClosureBodiesUnchecked) {
   assert(!PBD->isInitializerChecked(bindingIndex) &&
          PBD->getInit(bindingIndex));
 
   auto &Ctx = PBD->getASTContext();
   DiagnosticSuppression suppression(Ctx.Diags);
-  (void)evaluateOrDefault(
-      Ctx.evaluator, PatternBindingEntryRequest{PBD, bindingIndex}, nullptr);
-  TypeChecker::typeCheckPatternBinding(PBD, bindingIndex);
+
+  TypeCheckExprOptions options;
+  if (leaveClosureBodiesUnchecked)
+    options |= TypeCheckExprFlags::LeaveClosureBodyUnchecked;
+
+  TypeChecker::typeCheckPatternBinding(PBD, bindingIndex,
+                                       /*patternType=*/Type(), options);
 }
 
 bool swift::typeCheckASTNodeAtLoc(DeclContext *DC, SourceLoc TargetLoc) {

lib/Sema/TypeChecker.h

@@ -400,7 +400,7 @@ Type typeCheckParameterDefault(Expr *&defaultValue, DeclContext *DC,
 
 void typeCheckTopLevelCodeDecl(TopLevelCodeDecl *TLCD);
 
-void typeCheckDecl(Decl *D);
+void typeCheckDecl(Decl *D, bool LeaveClosureBodiesUnchecked = false);
 
 void addImplicitDynamicAttribute(Decl *D);
 void checkDeclAttributes(Decl *D);
@@ -665,9 +665,11 @@ void coerceParameterListToType(ParameterList *P, AnyFunctionType *FN);
 bool typeCheckBinding(Pattern *&P, Expr *&Init, DeclContext *DC,
                       Type patternType,
                       PatternBindingDecl *PBD = nullptr,
-                      unsigned patternNumber = 0);
+                      unsigned patternNumber = 0,
+                      TypeCheckExprOptions options = {});
 bool typeCheckPatternBinding(PatternBindingDecl *PBD, unsigned patternNumber,
-                             Type patternType = Type());
+                             Type patternType = Type(),
+                             TypeCheckExprOptions options = {});
 
 /// Type-check a for-each loop's pattern binding and sequence together.
 ///