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      1 //===-- llvm/MC/MCObjectFileInfo.h - Object File Info -----------*- C++ -*-===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file describes common object file formats.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #ifndef LLVM_MC_MCOBJECTFILEINFO_H
     15 #define LLVM_MC_MCOBJECTFILEINFO_H
     16 
     17 #include "llvm/ADT/Triple.h"
     18 #include "llvm/Support/CodeGen.h"
     19 
     20 namespace llvm {
     21 class MCContext;
     22 class MCSection;
     23 
     24 class MCObjectFileInfo {
     25 protected:
     26   /// True if .comm supports alignment.  This is a hack for as long as we
     27   /// support 10.4 Tiger, whose assembler doesn't support alignment on comm.
     28   bool CommDirectiveSupportsAlignment;
     29 
     30   /// True if target object file supports a weak_definition of constant 0 for an
     31   /// omitted EH frame.
     32   bool SupportsWeakOmittedEHFrame;
     33 
     34   /// True if the target object file supports emitting a compact unwind section
     35   /// without an associated EH frame section.
     36   bool SupportsCompactUnwindWithoutEHFrame;
     37 
     38   /// OmitDwarfIfHaveCompactUnwind - True if the target object file
     39   /// supports having some functions with compact unwind and other with
     40   /// dwarf unwind.
     41   bool OmitDwarfIfHaveCompactUnwind;
     42 
     43   /// PersonalityEncoding, LSDAEncoding, TTypeEncoding - Some encoding values
     44   /// for EH.
     45   unsigned PersonalityEncoding;
     46   unsigned LSDAEncoding;
     47   unsigned FDECFIEncoding;
     48   unsigned TTypeEncoding;
     49 
     50   /// Compact unwind encoding indicating that we should emit only an EH frame.
     51   unsigned CompactUnwindDwarfEHFrameOnly;
     52 
     53   /// Section directive for standard text.
     54   MCSection *TextSection;
     55 
     56   /// Section directive for standard data.
     57   MCSection *DataSection;
     58 
     59   /// Section that is default initialized to zero.
     60   MCSection *BSSSection;
     61 
     62   /// Section that is readonly and can contain arbitrary initialized data.
     63   /// Targets are not required to have a readonly section. If they don't,
     64   /// various bits of code will fall back to using the data section for
     65   /// constants.
     66   MCSection *ReadOnlySection;
     67 
     68   /// This section contains the static constructor pointer list.
     69   MCSection *StaticCtorSection;
     70 
     71   /// This section contains the static destructor pointer list.
     72   MCSection *StaticDtorSection;
     73 
     74   /// If exception handling is supported by the target, this is the section the
     75   /// Language Specific Data Area information is emitted to.
     76   MCSection *LSDASection;
     77 
     78   /// If exception handling is supported by the target and the target can
     79   /// support a compact representation of the CIE and FDE, this is the section
     80   /// to emit them into.
     81   MCSection *CompactUnwindSection;
     82 
     83   // Dwarf sections for debug info.  If a target supports debug info, these must
     84   // be set.
     85   MCSection *DwarfAbbrevSection;
     86   MCSection *DwarfInfoSection;
     87   MCSection *DwarfLineSection;
     88   MCSection *DwarfFrameSection;
     89   MCSection *DwarfPubTypesSection;
     90   const MCSection *DwarfDebugInlineSection;
     91   MCSection *DwarfStrSection;
     92   MCSection *DwarfLocSection;
     93   MCSection *DwarfARangesSection;
     94   MCSection *DwarfRangesSection;
     95   // The pubnames section is no longer generated by default.  The generation
     96   // can be enabled by a compiler flag.
     97   MCSection *DwarfPubNamesSection;
     98 
     99   /// DWARF5 Experimental Debug Info Sections
    100   /// DwarfAccelNamesSection, DwarfAccelObjCSection,
    101   /// DwarfAccelNamespaceSection, DwarfAccelTypesSection -
    102   /// If we use the DWARF accelerated hash tables then we want to emit these
    103   /// sections.
    104   MCSection *DwarfAccelNamesSection;
    105   MCSection *DwarfAccelObjCSection;
    106   MCSection *DwarfAccelNamespaceSection;
    107   MCSection *DwarfAccelTypesSection;
    108 
    109   // These are used for the Fission separate debug information files.
    110   MCSection *DwarfInfoDWOSection;
    111   MCSection *DwarfTypesDWOSection;
    112   MCSection *DwarfAbbrevDWOSection;
    113   MCSection *DwarfStrDWOSection;
    114   MCSection *DwarfLineDWOSection;
    115   MCSection *DwarfLocDWOSection;
    116   MCSection *DwarfStrOffDWOSection;
    117   MCSection *DwarfAddrSection;
    118 
    119   // These are for Fission DWP files.
    120   MCSection *DwarfCUIndexSection;
    121   MCSection *DwarfTUIndexSection;
    122 
    123   /// Section for newer gnu pubnames.
    124   MCSection *DwarfGnuPubNamesSection;
    125   /// Section for newer gnu pubtypes.
    126   MCSection *DwarfGnuPubTypesSection;
    127 
    128   MCSection *COFFDebugSymbolsSection;
    129 
    130   /// Extra TLS Variable Data section.
    131   ///
    132   /// If the target needs to put additional information for a TLS variable,
    133   /// it'll go here.
    134   MCSection *TLSExtraDataSection;
    135 
    136   /// Section directive for Thread Local data. ELF, MachO and COFF.
    137   MCSection *TLSDataSection; // Defaults to ".tdata".
    138 
    139   /// Section directive for Thread Local uninitialized data.
    140   ///
    141   /// Null if this target doesn't support a BSS section. ELF and MachO only.
    142   MCSection *TLSBSSSection; // Defaults to ".tbss".
    143 
    144   /// StackMap section.
    145   MCSection *StackMapSection;
    146 
    147   /// FaultMap section.
    148   MCSection *FaultMapSection;
    149 
    150   /// EH frame section.
    151   ///
    152   /// It is initialized on demand so it can be overwritten (with uniquing).
    153   MCSection *EHFrameSection;
    154 
    155   // ELF specific sections.
    156   MCSection *DataRelROSection;
    157   MCSection *MergeableConst4Section;
    158   MCSection *MergeableConst8Section;
    159   MCSection *MergeableConst16Section;
    160 
    161   // MachO specific sections.
    162 
    163   /// Section for thread local structure information.
    164   ///
    165   /// Contains the source code name of the variable, visibility and a pointer to
    166   /// the initial value (.tdata or .tbss).
    167   MCSection *TLSTLVSection; // Defaults to ".tlv".
    168 
    169   /// Section for thread local data initialization functions.
    170   const MCSection *TLSThreadInitSection; // Defaults to ".thread_init_func".
    171 
    172   MCSection *CStringSection;
    173   MCSection *UStringSection;
    174   MCSection *TextCoalSection;
    175   MCSection *ConstTextCoalSection;
    176   MCSection *ConstDataSection;
    177   MCSection *DataCoalSection;
    178   MCSection *DataCommonSection;
    179   MCSection *DataBSSSection;
    180   MCSection *FourByteConstantSection;
    181   MCSection *EightByteConstantSection;
    182   MCSection *SixteenByteConstantSection;
    183   MCSection *LazySymbolPointerSection;
    184   MCSection *NonLazySymbolPointerSection;
    185 
    186   /// COFF specific sections.
    187   MCSection *DrectveSection;
    188   MCSection *PDataSection;
    189   MCSection *XDataSection;
    190   MCSection *SXDataSection;
    191 
    192 public:
    193   void InitMCObjectFileInfo(const Triple &TT, Reloc::Model RM,
    194                             CodeModel::Model CM, MCContext &ctx);
    195   LLVM_ATTRIBUTE_DEPRECATED(
    196       void InitMCObjectFileInfo(StringRef TT, Reloc::Model RM,
    197                                 CodeModel::Model CM, MCContext &ctx),
    198       "StringRef GNU Triple argument replaced by a llvm::Triple object");
    199 
    200   bool getSupportsWeakOmittedEHFrame() const {
    201     return SupportsWeakOmittedEHFrame;
    202   }
    203   bool getSupportsCompactUnwindWithoutEHFrame() const {
    204     return SupportsCompactUnwindWithoutEHFrame;
    205   }
    206   bool getOmitDwarfIfHaveCompactUnwind() const {
    207     return OmitDwarfIfHaveCompactUnwind;
    208   }
    209 
    210   bool getCommDirectiveSupportsAlignment() const {
    211     return CommDirectiveSupportsAlignment;
    212   }
    213 
    214   unsigned getPersonalityEncoding() const { return PersonalityEncoding; }
    215   unsigned getLSDAEncoding() const { return LSDAEncoding; }
    216   unsigned getFDEEncoding() const { return FDECFIEncoding; }
    217   unsigned getTTypeEncoding() const { return TTypeEncoding; }
    218 
    219   unsigned getCompactUnwindDwarfEHFrameOnly() const {
    220     return CompactUnwindDwarfEHFrameOnly;
    221   }
    222 
    223   MCSection *getTextSection() const { return TextSection; }
    224   MCSection *getDataSection() const { return DataSection; }
    225   MCSection *getBSSSection() const { return BSSSection; }
    226   MCSection *getReadOnlySection() const { return ReadOnlySection; }
    227   MCSection *getLSDASection() const { return LSDASection; }
    228   MCSection *getCompactUnwindSection() const { return CompactUnwindSection; }
    229   MCSection *getDwarfAbbrevSection() const { return DwarfAbbrevSection; }
    230   MCSection *getDwarfInfoSection() const { return DwarfInfoSection; }
    231   MCSection *getDwarfLineSection() const { return DwarfLineSection; }
    232   MCSection *getDwarfFrameSection() const { return DwarfFrameSection; }
    233   MCSection *getDwarfPubNamesSection() const { return DwarfPubNamesSection; }
    234   MCSection *getDwarfPubTypesSection() const { return DwarfPubTypesSection; }
    235   MCSection *getDwarfGnuPubNamesSection() const {
    236     return DwarfGnuPubNamesSection;
    237   }
    238   MCSection *getDwarfGnuPubTypesSection() const {
    239     return DwarfGnuPubTypesSection;
    240   }
    241   const MCSection *getDwarfDebugInlineSection() const {
    242     return DwarfDebugInlineSection;
    243   }
    244   MCSection *getDwarfStrSection() const { return DwarfStrSection; }
    245   MCSection *getDwarfLocSection() const { return DwarfLocSection; }
    246   MCSection *getDwarfARangesSection() const { return DwarfARangesSection; }
    247   MCSection *getDwarfRangesSection() const { return DwarfRangesSection; }
    248 
    249   // DWARF5 Experimental Debug Info Sections
    250   MCSection *getDwarfAccelNamesSection() const {
    251     return DwarfAccelNamesSection;
    252   }
    253   MCSection *getDwarfAccelObjCSection() const { return DwarfAccelObjCSection; }
    254   MCSection *getDwarfAccelNamespaceSection() const {
    255     return DwarfAccelNamespaceSection;
    256   }
    257   MCSection *getDwarfAccelTypesSection() const {
    258     return DwarfAccelTypesSection;
    259   }
    260   MCSection *getDwarfInfoDWOSection() const { return DwarfInfoDWOSection; }
    261   MCSection *getDwarfTypesSection(uint64_t Hash) const;
    262   MCSection *getDwarfTypesDWOSection() const { return DwarfTypesDWOSection; }
    263   MCSection *getDwarfAbbrevDWOSection() const { return DwarfAbbrevDWOSection; }
    264   MCSection *getDwarfStrDWOSection() const { return DwarfStrDWOSection; }
    265   MCSection *getDwarfLineDWOSection() const { return DwarfLineDWOSection; }
    266   MCSection *getDwarfLocDWOSection() const { return DwarfLocDWOSection; }
    267   MCSection *getDwarfStrOffDWOSection() const { return DwarfStrOffDWOSection; }
    268   MCSection *getDwarfAddrSection() const { return DwarfAddrSection; }
    269   MCSection *getDwarfCUIndexSection() const { return DwarfCUIndexSection; }
    270   MCSection *getDwarfTUIndexSection() const { return DwarfTUIndexSection; }
    271 
    272   MCSection *getCOFFDebugSymbolsSection() const {
    273     return COFFDebugSymbolsSection;
    274   }
    275 
    276   MCSection *getTLSExtraDataSection() const { return TLSExtraDataSection; }
    277   const MCSection *getTLSDataSection() const { return TLSDataSection; }
    278   MCSection *getTLSBSSSection() const { return TLSBSSSection; }
    279 
    280   MCSection *getStackMapSection() const { return StackMapSection; }
    281   MCSection *getFaultMapSection() const { return FaultMapSection; }
    282 
    283   // ELF specific sections.
    284   MCSection *getDataRelROSection() const { return DataRelROSection; }
    285   const MCSection *getMergeableConst4Section() const {
    286     return MergeableConst4Section;
    287   }
    288   const MCSection *getMergeableConst8Section() const {
    289     return MergeableConst8Section;
    290   }
    291   const MCSection *getMergeableConst16Section() const {
    292     return MergeableConst16Section;
    293   }
    294 
    295   // MachO specific sections.
    296   const MCSection *getTLSTLVSection() const { return TLSTLVSection; }
    297   const MCSection *getTLSThreadInitSection() const {
    298     return TLSThreadInitSection;
    299   }
    300   const MCSection *getCStringSection() const { return CStringSection; }
    301   const MCSection *getUStringSection() const { return UStringSection; }
    302   MCSection *getTextCoalSection() const { return TextCoalSection; }
    303   const MCSection *getConstTextCoalSection() const {
    304     return ConstTextCoalSection;
    305   }
    306   const MCSection *getConstDataSection() const { return ConstDataSection; }
    307   const MCSection *getDataCoalSection() const { return DataCoalSection; }
    308   const MCSection *getDataCommonSection() const { return DataCommonSection; }
    309   MCSection *getDataBSSSection() const { return DataBSSSection; }
    310   const MCSection *getFourByteConstantSection() const {
    311     return FourByteConstantSection;
    312   }
    313   const MCSection *getEightByteConstantSection() const {
    314     return EightByteConstantSection;
    315   }
    316   const MCSection *getSixteenByteConstantSection() const {
    317     return SixteenByteConstantSection;
    318   }
    319   MCSection *getLazySymbolPointerSection() const {
    320     return LazySymbolPointerSection;
    321   }
    322   MCSection *getNonLazySymbolPointerSection() const {
    323     return NonLazySymbolPointerSection;
    324   }
    325 
    326   // COFF specific sections.
    327   MCSection *getDrectveSection() const { return DrectveSection; }
    328   MCSection *getPDataSection() const { return PDataSection; }
    329   MCSection *getXDataSection() const { return XDataSection; }
    330   MCSection *getSXDataSection() const { return SXDataSection; }
    331 
    332   MCSection *getEHFrameSection() {
    333     return EHFrameSection;
    334   }
    335 
    336   enum Environment { IsMachO, IsELF, IsCOFF };
    337   Environment getObjectFileType() const { return Env; }
    338 
    339   Reloc::Model getRelocM() const { return RelocM; }
    340 
    341 private:
    342   Environment Env;
    343   Reloc::Model RelocM;
    344   CodeModel::Model CMModel;
    345   MCContext *Ctx;
    346   Triple TT;
    347 
    348   void initMachOMCObjectFileInfo(Triple T);
    349   void initELFMCObjectFileInfo(Triple T);
    350   void initCOFFMCObjectFileInfo(Triple T);
    351 
    352 public:
    353   const Triple &getTargetTriple() const { return TT; }
    354 };
    355 
    356 } // end namespace llvm
    357 
    358 #endif
    359