X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FMC%2FMCSectionELF.h;h=4d54465760d4ead69b84fec13e35a18540fbde23;hb=f29c05e883dc46f3f1be9b3a5f5c50ee73899380;hp=c48ff03e6d79873baf019e59a952e5e4726d5019;hpb=a46918d2b1b63aa3db94aa10b9ea70209b84e274;p=oota-llvm.git diff --git a/include/llvm/MC/MCSectionELF.h b/include/llvm/MC/MCSectionELF.h index c48ff03e6d7..4d54465760d 100644 --- a/include/llvm/MC/MCSectionELF.h +++ b/include/llvm/MC/MCSectionELF.h @@ -15,174 +15,71 @@ #define LLVM_MC_MCSECTIONELF_H #include "llvm/MC/MCSection.h" +#include "llvm/Support/ELF.h" +#include "llvm/ADT/StringRef.h" namespace llvm { - + +class MCSymbol; + /// MCSectionELF - This represents a section on linux, lots of unix variants /// and some bare metal systems. class MCSectionELF : public MCSection { - std::string SectionName; - + /// SectionName - This is the name of the section. The referenced memory is + /// owned by TargetLoweringObjectFileELF's ELFUniqueMap. + StringRef SectionName; + /// Type - This is the sh_type field of a section, drawn from the enums below. unsigned Type; - + /// Flags - This is the sh_flags field of a section, drawn from the enums. /// below. unsigned Flags; - /// IsExplicit - Indicates that this section comes from globals with an - /// explicit section specfied. - bool IsExplicit; - -protected: + /// EntrySize - The size of each entry in this section. This size only + /// makes sense for sections that contain fixed-sized entries. If a + /// section does not contain fixed-sized entries 'EntrySize' will be 0. + unsigned EntrySize; + + const MCSymbol *Group; + +private: + friend class MCContext; MCSectionELF(StringRef Section, unsigned type, unsigned flags, - SectionKind K, bool isExplicit) - : MCSection(K), SectionName(Section.str()), Type(type), Flags(flags), - IsExplicit(isExplicit) {} + SectionKind K, unsigned entrySize, const MCSymbol *group) + : MCSection(SV_ELF, K), SectionName(Section), Type(type), Flags(flags), + EntrySize(entrySize), Group(group) {} + ~MCSectionELF(); public: - - static MCSectionELF *Create(StringRef Section, unsigned Type, - unsigned Flags, SectionKind K, bool isExplicit, - MCContext &Ctx); /// ShouldOmitSectionDirective - Decides whether a '.section' directive /// should be printed before the section name bool ShouldOmitSectionDirective(StringRef Name, const MCAsmInfo &MAI) const; - /// ShouldPrintSectionType - Only prints the section type if supported - bool ShouldPrintSectionType(unsigned Ty) const; - - /// HasCommonSymbols - True if this section holds common symbols, this is - /// indicated on the ELF object file by a symbol with SHN_COMMON section - /// header index. - bool HasCommonSymbols() const; - - /// These are the section type and flags fields. An ELF section can have - /// only one Type, but can have more than one of the flags specified. - /// - /// Valid section types. - enum { - // This value marks the section header as inactive. - SHT_NULL = 0x00U, - - // Holds information defined by the program, with custom format and meaning. - SHT_PROGBITS = 0x01U, - - // This section holds a symbol table. - SHT_SYMTAB = 0x02U, - - // The section holds a string table. - SHT_STRTAB = 0x03U, - - // The section holds relocation entries with explicit addends. - SHT_RELA = 0x04U, - - // The section holds a symbol hash table. - SHT_HASH = 0x05U, - - // Information for dynamic linking. - SHT_DYNAMIC = 0x06U, - - // The section holds information that marks the file in some way. - SHT_NOTE = 0x07U, - - // A section of this type occupies no space in the file. - SHT_NOBITS = 0x08U, - - // The section holds relocation entries without explicit addends. - SHT_REL = 0x09U, - - // This section type is reserved but has unspecified semantics. - SHT_SHLIB = 0x0AU, - - // This section holds a symbol table. - SHT_DYNSYM = 0x0BU, - - // This section contains an array of pointers to initialization functions. - SHT_INIT_ARRAY = 0x0EU, - - // This section contains an array of pointers to termination functions. - SHT_FINI_ARRAY = 0x0FU, - - // This section contains an array of pointers to functions that are invoked - // before all other initialization functions. - SHT_PREINIT_ARRAY = 0x10U, - - // A section group is a set of sections that are related and that must be - // treated specially by the linker. - SHT_GROUP = 0x11U, - - // This section is associated with a section of type SHT_SYMTAB, when the - // referenced symbol table contain the escape value SHN_XINDEX - SHT_SYMTAB_SHNDX = 0x12U, - - LAST_KNOWN_SECTION_TYPE = SHT_SYMTAB_SHNDX - }; - - /// Valid section flags. - enum { - // The section contains data that should be writable. - SHF_WRITE = 0x1U, - - // The section occupies memory during execution. - SHF_ALLOC = 0x2U, - - // The section contains executable machine instructions. - SHF_EXECINSTR = 0x4U, - - // The data in the section may be merged to eliminate duplication. - SHF_MERGE = 0x10U, - - // Elements in the section consist of null-terminated character strings. - SHF_STRINGS = 0x20U, - - // A field in this section holds a section header table index. - SHF_INFO_LINK = 0x40U, - - // Adds special ordering requirements for link editors. - SHF_LINK_ORDER = 0x80U, - - // This section requires special OS-specific processing to avoid incorrect - // behavior. - SHF_OS_NONCONFORMING = 0x100U, - - // This section is a member of a section group. - SHF_GROUP = 0x200U, - - // This section holds Thread-Local Storage. - SHF_TLS = 0x400U, - - /// FIRST_TARGET_DEP_FLAG - This is the first flag that subclasses are - /// allowed to specify. - FIRST_TARGET_DEP_FLAG = 0x800U, - - /// TARGET_INDEP_SHF - This is the bitmask for all the target independent - /// section flags. Targets can define their own target flags above these. - /// If they do that, they should implement their own MCSectionELF subclasses - /// and implement the virtual method hooks below to handle printing needs. - TARGET_INDEP_SHF = FIRST_TARGET_DEP_FLAG-1U - }; - - StringRef getSectionName() const { - return StringRef(SectionName); - } - + StringRef getSectionName() const { return SectionName; } unsigned getType() const { return Type; } unsigned getFlags() const { return Flags; } - - virtual void PrintSwitchToSection(const MCAsmInfo &MAI, - raw_ostream &OS) const; - - - /// PrintTargetSpecificSectionFlags - Targets that define their own - /// MCSectionELF subclasses with target specific section flags should - /// implement this method if they end up adding letters to the attributes - /// list. - virtual void PrintTargetSpecificSectionFlags(const MCAsmInfo &MAI, - raw_ostream &OS) const { + unsigned getEntrySize() const { return EntrySize; } + const MCSymbol *getGroup() const { return Group; } + + void PrintSwitchToSection(const MCAsmInfo &MAI, + raw_ostream &OS) const; + virtual bool UseCodeAlign() const; + virtual bool isVirtualSection() const; + + /// isBaseAddressKnownZero - We know that non-allocatable sections (like + /// debug info) have a base of zero. + virtual bool isBaseAddressKnownZero() const { + return (getFlags() & ELF::SHF_ALLOC) == 0; + } + + static bool classof(const MCSection *S) { + return S->getVariant() == SV_ELF; } - - + + // Return the entry size for sections with fixed-width data. + static unsigned DetermineEntrySize(SectionKind Kind); + }; } // end namespace llvm