Fold exportability checking into availability checking

lib/Sema/ResilienceDiagnostics.cpp

@@ -27,53 +27,47 @@
 
 using namespace swift;
 
-/// A uniquely-typed boolean to reduce the chances of accidentally inverting
-/// a check.
-enum class DowngradeToWarning: bool {
-  No,
-  Yes
-};
-
 bool TypeChecker::diagnoseInlinableDeclRef(SourceLoc loc,
-                                           ConcreteDeclRef declRef,
-                                           const DeclContext *DC,
-                                           FragileFunctionKind Kind) {
-  assert(Kind.kind != FragileFunctionKind::None);
+                                           const ValueDecl *D,
+                                           ExportContext where) {
+  auto fragileKind = where.getFragileFunctionKind();
+  if (fragileKind.kind == FragileFunctionKind::None)
+    return false;
 
-  const ValueDecl *D = declRef.getDecl();
   // Do some important fast-path checks that apply to all cases.
 
   // Type parameters are OK.
   if (isa<AbstractTypeParamDecl>(D))
     return false;
 
   // Check whether the declaration is accessible.
-  if (diagnoseInlinableDeclRefAccess(loc, D, DC, Kind))
+  if (diagnoseInlinableDeclRefAccess(loc, D, where))
     return true;
 
   // Check whether the declaration comes from a publically-imported module.
   // Skip this check for accessors because the associated property or subscript
   // will also be checked, and will provide a better error message.
   if (!isa<AccessorDecl>(D))
-    if (diagnoseDeclRefExportability(loc, declRef, DC, Kind))
+    if (diagnoseDeclRefExportability(loc, D, where))
       return true;
 
   return false;
 }
 
 bool TypeChecker::diagnoseInlinableDeclRefAccess(SourceLoc loc,
-                                           const ValueDecl *D,
-                                           const DeclContext *DC,
-                                           FragileFunctionKind Kind) {
-  assert(Kind.kind != FragileFunctionKind::None);
+                                                 const ValueDecl *D,
+                                                 ExportContext where) {
+  auto *DC = where.getDeclContext();
+  auto fragileKind = where.getFragileFunctionKind();
+  assert(fragileKind.kind != FragileFunctionKind::None);
 
   // Local declarations are OK.
   if (D->getDeclContext()->isLocalContext())
     return false;
 
   // Public declarations or SPI used from SPI are OK.
   if (D->getFormalAccessScope(/*useDC=*/nullptr,
-                              Kind.allowUsableFromInline).isPublic() &&
+                              fragileKind.allowUsableFromInline).isPublic() &&
       !(D->isSPI() && !DC->getInnermostDeclarationDeclContext()->isSPI()))
     return false;
 
@@ -133,10 +127,10 @@ bool TypeChecker::diagnoseInlinableDeclRefAccess(SourceLoc loc,
            loc, diagID,
            D->getDescriptiveKind(), diagName,
            D->getFormalAccessScope().accessLevelForDiagnostics(),
-           static_cast<unsigned>(Kind.kind),
+           static_cast<unsigned>(fragileKind.kind),
            isAccessor);
 
-  if (Kind.allowUsableFromInline) {
+  if (fragileKind.allowUsableFromInline) {
     Context.Diags.diagnose(D, diag::resilience_decl_declared_here,
                            D->getDescriptiveKind(), diagName, isAccessor);
   } else {
@@ -147,99 +141,74 @@ bool TypeChecker::diagnoseInlinableDeclRefAccess(SourceLoc loc,
   return (downgradeToWarning == DowngradeToWarning::No);
 }
 
-static bool diagnoseDeclExportability(SourceLoc loc, const ValueDecl *D,
-                                      const SourceFile &userSF,
-                                      const DeclContext *userDC,
-                                      FragileFunctionKind fragileKind) {
-  assert(fragileKind.kind != FragileFunctionKind::None);
+bool
+TypeChecker::diagnoseDeclRefExportability(SourceLoc loc,
+                                          const ValueDecl *D,
+                                          ExportContext where) {
+  if (!where.mustOnlyReferenceExportedDecls())
+    return false;
 
   auto definingModule = D->getModuleContext();
 
+  auto downgradeToWarning = DowngradeToWarning::No;
+
   auto originKind = getDisallowedOriginKind(
-      D, userSF, userDC->getInnermostDeclarationDeclContext());
+      D, where, downgradeToWarning);
   if (originKind == DisallowedOriginKind::None)
     return false;
 
-  // TODO: different diagnostics
   ASTContext &ctx = definingModule->getASTContext();
-  ctx.Diags.diagnose(loc, diag::inlinable_decl_ref_from_hidden_module,
-                     D->getDescriptiveKind(), D->getName(),
-                     static_cast<unsigned>(fragileKind.kind),
-                     definingModule->getName(),
-                     static_cast<unsigned>(originKind));
-  return true;
-}
 
-static bool
-diagnoseGenericArgumentsExportability(SourceLoc loc,
-                                      SubstitutionMap subs,
-                                      const SourceFile &userSF,
-                                      const DeclContext *userDC) {
-  bool hadAnyIssues = false;
-  for (ProtocolConformanceRef conformance : subs.getConformances()) {
-    if (!conformance.isConcrete())
-      continue;
-    const ProtocolConformance *concreteConf = conformance.getConcrete();
-
-    SubstitutionMap subConformanceSubs =
-        concreteConf->getSubstitutions(userSF.getParentModule());
-    diagnoseGenericArgumentsExportability(loc, subConformanceSubs, userSF, userDC);
-
-    const RootProtocolConformance *rootConf =
-        concreteConf->getRootConformance();
-    ModuleDecl *M = rootConf->getDeclContext()->getParentModule();
-
-    auto originKind = getDisallowedOriginKind(
-        rootConf->getDeclContext()->getAsDecl(),
-        userSF, userDC->getInnermostDeclarationDeclContext());
-    if (originKind == DisallowedOriginKind::None)
-      continue;
-
-    ASTContext &ctx = M->getASTContext();
-    ctx.Diags.diagnose(loc, diag::conformance_from_implementation_only_module,
-                       rootConf->getType(),
-                       rootConf->getProtocol()->getName(), 0, M->getName(),
+  auto fragileKind = where.getFragileFunctionKind();
+  auto reason = where.getExportabilityReason();
+
+  if (fragileKind.kind == FragileFunctionKind::None) {
+    auto errorOrWarning = downgradeToWarning == DowngradeToWarning::Yes?
+                              diag::decl_from_hidden_module_warn:
+                              diag::decl_from_hidden_module;
+    ctx.Diags.diagnose(loc, errorOrWarning,
+                       D->getDescriptiveKind(),
+                       D->getName(),
+                       static_cast<unsigned>(*reason),
+                       definingModule->getName(),
                        static_cast<unsigned>(originKind));
-    hadAnyIssues = true;
-  }
-  return hadAnyIssues;
-}
 
-void TypeChecker::diagnoseGenericTypeExportability(SourceLoc Loc, Type T,
-                                                   const DeclContext *DC) {
-  const SourceFile *SF = DC->getParentSourceFile();
-  if (!SF)
-    return;
-
-  // FIXME: It would be nice to highlight just the part of the type that's
-  // problematic, but unfortunately the TypeRepr doesn't have the
-  // information we need and the Type doesn't easily map back to it.
-  if (auto *BGT = dyn_cast<BoundGenericType>(T.getPointer())) {
-    ModuleDecl *useModule = SF->getParentModule();
-    auto subs = T->getContextSubstitutionMap(useModule, BGT->getDecl());
-    (void)diagnoseGenericArgumentsExportability(Loc, subs, *SF, DC);
-  } else if (auto *TAT = dyn_cast<TypeAliasType>(T.getPointer())) {
-    auto subs = TAT->getSubstitutionMap();
-    (void)diagnoseGenericArgumentsExportability(Loc, subs, *SF, DC);
+    D->diagnose(diag::kind_declared_here, DescriptiveDeclKind::Type);
+  } else {
+    ctx.Diags.diagnose(loc, diag::inlinable_decl_ref_from_hidden_module,
+                       D->getDescriptiveKind(), D->getName(),
+                       static_cast<unsigned>(fragileKind.kind),
+                       definingModule->getName(),
+                       static_cast<unsigned>(originKind));
   }
+  return true;
 }
 
 bool
-TypeChecker::diagnoseDeclRefExportability(SourceLoc loc,
-                                          ConcreteDeclRef declRef,
-                                          const DeclContext *DC,
-                                          FragileFunctionKind fragileKind) {
-  // We're only interested in diagnosing uses from source files.
-  auto userSF = DC->getParentSourceFile();
-  if (!userSF)
+TypeChecker::diagnoseConformanceExportability(SourceLoc loc,
+                                              const RootProtocolConformance *rootConf,
+                                              ExportContext where) {
+  if (!where.mustOnlyReferenceExportedDecls())
     return false;
 
-  const ValueDecl *D = declRef.getDecl();
-  if (diagnoseDeclExportability(loc, D, *userSF, DC, fragileKind))
-    return true;
-  if (diagnoseGenericArgumentsExportability(loc, declRef.getSubstitutions(),
-                                            *userSF, DC)) {
-    return true;
-  }
-  return false;
+  auto originKind = getDisallowedOriginKind(
+      rootConf->getDeclContext()->getAsDecl(),
+      where);
+  if (originKind == DisallowedOriginKind::None)
+    return false;
+
+  ModuleDecl *M = rootConf->getDeclContext()->getParentModule();
+  ASTContext &ctx = M->getASTContext();
+
+  auto reason = where.getExportabilityReason();
+  if (!reason.hasValue())
+    reason = ExportabilityReason::General;
+
+  ctx.Diags.diagnose(loc, diag::conformance_from_implementation_only_module,
+                     rootConf->getType(),
+                     rootConf->getProtocol()->getName(),
+                     static_cast<unsigned>(*reason),
+                     M->getName(),
+                     static_cast<unsigned>(originKind));
+  return true;
 }