diff options
Diffstat (limited to 'include/clang/AST/DeclBase.h')
| -rw-r--r-- | include/clang/AST/DeclBase.h | 155 |
1 files changed, 97 insertions, 58 deletions
diff --git a/include/clang/AST/DeclBase.h b/include/clang/AST/DeclBase.h index c26e2d7bde95..0f1f481ae49b 100644 --- a/include/clang/AST/DeclBase.h +++ b/include/clang/AST/DeclBase.h @@ -202,26 +202,33 @@ public: OBJC_TQ_CSNullability = 0x40 }; -protected: - // Enumeration values used in the bits stored in NextInContextAndBits. - enum { - /// \brief Whether this declaration is a top-level declaration (function, - /// global variable, etc.) that is lexically inside an objc container - /// definition. - TopLevelDeclInObjCContainerFlag = 0x01, - - /// \brief Whether this declaration is private to the module in which it was - /// defined. - ModulePrivateFlag = 0x02 + /// The kind of ownership a declaration has, for visibility purposes. + /// This enumeration is designed such that higher values represent higher + /// levels of name hiding. + enum class ModuleOwnershipKind : unsigned { + /// This declaration is not owned by a module. + Unowned, + /// This declaration has an owning module, but is globally visible + /// (typically because its owning module is visible and we know that + /// modules cannot later become hidden in this compilation). + /// After serialization and deserialization, this will be converted + /// to VisibleWhenImported. + Visible, + /// This declaration has an owning module, and is visible when that + /// module is imported. + VisibleWhenImported, + /// This declaration has an owning module, but is only visible to + /// lookups that occur within that module. + ModulePrivate }; - + +protected: /// \brief The next declaration within the same lexical /// DeclContext. These pointers form the linked list that is /// traversed via DeclContext's decls_begin()/decls_end(). /// - /// The extra two bits are used for the TopLevelDeclInObjCContainer and - /// ModulePrivate bits. - llvm::PointerIntPair<Decl *, 2, unsigned> NextInContextAndBits; + /// The extra two bits are used for the ModuleOwnershipKind. + llvm::PointerIntPair<Decl *, 2, ModuleOwnershipKind> NextInContextAndBits; private: friend class DeclContext; @@ -282,6 +289,11 @@ private: /// are regarded as "referenced" but not "used". unsigned Referenced : 1; + /// \brief Whether this declaration is a top-level declaration (function, + /// global variable, etc.) that is lexically inside an objc container + /// definition. + unsigned TopLevelDeclInObjCContainer : 1; + /// \brief Whether statistic collection is enabled. static bool StatisticsEnabled; @@ -294,11 +306,6 @@ protected: /// \brief Whether this declaration was loaded from an AST file. unsigned FromASTFile : 1; - /// \brief Whether this declaration is hidden from normal name lookup, e.g., - /// because it is was loaded from an AST file is either module-private or - /// because its submodule has not been made visible. - unsigned Hidden : 1; - /// IdentifierNamespace - This specifies what IDNS_* namespace this lives in. unsigned IdentifierNamespace : 13; @@ -332,26 +339,38 @@ protected: private: bool AccessDeclContextSanity() const; + /// Get the module ownership kind to use for a local lexical child of \p DC, + /// which may be either a local or (rarely) an imported declaration. + static ModuleOwnershipKind getModuleOwnershipKindForChildOf(DeclContext *DC) { + if (DC) { + auto *D = cast<Decl>(DC); + auto MOK = D->getModuleOwnershipKind(); + if (MOK != ModuleOwnershipKind::Unowned && + (!D->isFromASTFile() || D->hasLocalOwningModuleStorage())) + return MOK; + // If D is not local and we have no local module storage, then we don't + // need to track module ownership at all. + } + return ModuleOwnershipKind::Unowned; + } + protected: Decl(Kind DK, DeclContext *DC, SourceLocation L) - : NextInContextAndBits(), DeclCtx(DC), Loc(L), DeclKind(DK), - InvalidDecl(0), HasAttrs(false), Implicit(false), Used(false), - Referenced(false), Access(AS_none), FromASTFile(0), - Hidden(DC && cast<Decl>(DC)->Hidden && - (!cast<Decl>(DC)->isFromASTFile() || - hasLocalOwningModuleStorage())), + : NextInContextAndBits(nullptr, getModuleOwnershipKindForChildOf(DC)), + DeclCtx(DC), Loc(L), DeclKind(DK), InvalidDecl(0), HasAttrs(false), + Implicit(false), Used(false), Referenced(false), + TopLevelDeclInObjCContainer(false), Access(AS_none), FromASTFile(0), IdentifierNamespace(getIdentifierNamespaceForKind(DK)), CacheValidAndLinkage(0) { if (StatisticsEnabled) add(DK); } Decl(Kind DK, EmptyShell Empty) - : NextInContextAndBits(), DeclKind(DK), InvalidDecl(0), - HasAttrs(false), Implicit(false), Used(false), Referenced(false), - Access(AS_none), FromASTFile(0), Hidden(0), - IdentifierNamespace(getIdentifierNamespaceForKind(DK)), - CacheValidAndLinkage(0) - { + : NextInContextAndBits(), DeclKind(DK), InvalidDecl(0), HasAttrs(false), + Implicit(false), Used(false), Referenced(false), + TopLevelDeclInObjCContainer(false), Access(AS_none), FromASTFile(0), + IdentifierNamespace(getIdentifierNamespaceForKind(DK)), + CacheValidAndLinkage(0) { if (StatisticsEnabled) add(DK); } @@ -551,16 +570,11 @@ public: /// global variable, etc.) that is lexically inside an objc container /// definition. bool isTopLevelDeclInObjCContainer() const { - return NextInContextAndBits.getInt() & TopLevelDeclInObjCContainerFlag; + return TopLevelDeclInObjCContainer; } void setTopLevelDeclInObjCContainer(bool V = true) { - unsigned Bits = NextInContextAndBits.getInt(); - if (V) - Bits |= TopLevelDeclInObjCContainerFlag; - else - Bits &= ~TopLevelDeclInObjCContainerFlag; - NextInContextAndBits.setInt(Bits); + TopLevelDeclInObjCContainer = V; } /// \brief Looks on this and related declarations for an applicable @@ -570,7 +584,7 @@ public: /// \brief Whether this declaration was marked as being private to the /// module in which it was defined. bool isModulePrivate() const { - return NextInContextAndBits.getInt() & ModulePrivateFlag; + return getModuleOwnershipKind() == ModuleOwnershipKind::ModulePrivate; } /// \brief Whether this declaration is exported (by virtue of being lexically @@ -585,15 +599,14 @@ public: const Attr *getDefiningAttr() const; protected: - /// \brief Specify whether this declaration was marked as being private + /// \brief Specify that this declaration was marked as being private /// to the module in which it was defined. - void setModulePrivate(bool MP = true) { - unsigned Bits = NextInContextAndBits.getInt(); - if (MP) - Bits |= ModulePrivateFlag; - else - Bits &= ~ModulePrivateFlag; - NextInContextAndBits.setInt(Bits); + void setModulePrivate() { + // The module-private specifier has no effect on unowned declarations. + // FIXME: We should track this in some way for source fidelity. + if (getModuleOwnershipKind() == ModuleOwnershipKind::Unowned) + return; + setModuleOwnershipKind(ModuleOwnershipKind::ModulePrivate); } /// \brief Set the owning module ID. @@ -692,7 +705,7 @@ public: /// \brief Get the imported owning module, if this decl is from an imported /// (non-local) module. Module *getImportedOwningModule() const { - if (!isFromASTFile()) + if (!isFromASTFile() || !hasOwningModule()) return nullptr; return getOwningModuleSlow(); @@ -701,31 +714,57 @@ public: /// \brief Get the local owning module, if known. Returns nullptr if owner is /// not yet known or declaration is not from a module. Module *getLocalOwningModule() const { - if (isFromASTFile() || !Hidden) + if (isFromASTFile() || !hasOwningModule()) return nullptr; assert(hasLocalOwningModuleStorage() && - "hidden local decl but no local module storage"); + "owned local decl but no local module storage"); return reinterpret_cast<Module *const *>(this)[-1]; } void setLocalOwningModule(Module *M) { - assert(!isFromASTFile() && Hidden && hasLocalOwningModuleStorage() && + assert(!isFromASTFile() && hasOwningModule() && + hasLocalOwningModuleStorage() && "should not have a cached owning module"); reinterpret_cast<Module **>(this)[-1] = M; } + /// Is this declaration owned by some module? + bool hasOwningModule() const { + return getModuleOwnershipKind() != ModuleOwnershipKind::Unowned; + } + + /// Get the module that owns this declaration. Module *getOwningModule() const { return isFromASTFile() ? getImportedOwningModule() : getLocalOwningModule(); } - /// \brief Determine whether this declaration is hidden from name lookup. - bool isHidden() const { return Hidden; } + /// \brief Determine whether this declaration might be hidden from name + /// lookup. Note that the declaration might be visible even if this returns + /// \c false, if the owning module is visible within the query context. + // FIXME: Rename this to make it clearer what it does. + bool isHidden() const { + return (int)getModuleOwnershipKind() > (int)ModuleOwnershipKind::Visible; + } + + /// Set that this declaration is globally visible, even if it came from a + /// module that is not visible. + void setVisibleDespiteOwningModule() { + if (hasOwningModule()) + setModuleOwnershipKind(ModuleOwnershipKind::Visible); + } + + /// \brief Get the kind of module ownership for this declaration. + ModuleOwnershipKind getModuleOwnershipKind() const { + return NextInContextAndBits.getInt(); + } /// \brief Set whether this declaration is hidden from name lookup. - void setHidden(bool Hide) { - assert((!Hide || isFromASTFile() || hasLocalOwningModuleStorage()) && - "declaration with no owning module can't be hidden"); - Hidden = Hide; + void setModuleOwnershipKind(ModuleOwnershipKind MOK) { + assert(!(getModuleOwnershipKind() == ModuleOwnershipKind::Unowned && + MOK != ModuleOwnershipKind::Unowned && !isFromASTFile() && + !hasLocalOwningModuleStorage()) && + "no storage available for owning module for this declaration"); + NextInContextAndBits.setInt(MOK); } unsigned getIdentifierNamespace() const { |