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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/DenseMap.h"
     18 #include "llvm/ADT/Triple.h"
     19 #include "llvm/MC/MCSymbol.h"
     20 #include "llvm/Support/CodeGen.h"
     21 
     22 namespace llvm {
     23 class MCContext;
     24 class MCSection;
     25 
     26 class MCObjectFileInfo {
     27 protected:
     28   /// True if .comm supports alignment.  This is a hack for as long as we
     29   /// support 10.4 Tiger, whose assembler doesn't support alignment on comm.
     30   bool CommDirectiveSupportsAlignment;
     31 
     32   /// True if target object file supports a weak_definition of constant 0 for an
     33   /// omitted EH frame.
     34   bool SupportsWeakOmittedEHFrame;
     35 
     36   /// True if the target object file supports emitting a compact unwind section
     37   /// without an associated EH frame section.
     38   bool SupportsCompactUnwindWithoutEHFrame;
     39 
     40   /// OmitDwarfIfHaveCompactUnwind - True if the target object file
     41   /// supports having some functions with compact unwind and other with
     42   /// dwarf unwind.
     43   bool OmitDwarfIfHaveCompactUnwind;
     44 
     45   /// PersonalityEncoding, LSDAEncoding, TTypeEncoding - Some encoding values
     46   /// for EH.
     47   unsigned PersonalityEncoding;
     48   unsigned LSDAEncoding;
     49   unsigned FDECFIEncoding;
     50   unsigned TTypeEncoding;
     51 
     52   /// Compact unwind encoding indicating that we should emit only an EH frame.
     53   unsigned CompactUnwindDwarfEHFrameOnly;
     54 
     55   /// Section directive for standard text.
     56   MCSection *TextSection;
     57 
     58   /// Section directive for standard data.
     59   MCSection *DataSection;
     60 
     61   /// Section that is default initialized to zero.
     62   MCSection *BSSSection;
     63 
     64   /// Section that is readonly and can contain arbitrary initialized data.
     65   /// Targets are not required to have a readonly section. If they don't,
     66   /// various bits of code will fall back to using the data section for
     67   /// constants.
     68   MCSection *ReadOnlySection;
     69 
     70   /// If exception handling is supported by the target, this is the section the
     71   /// Language Specific Data Area information is emitted to.
     72   MCSection *LSDASection;
     73 
     74   /// If exception handling is supported by the target and the target can
     75   /// support a compact representation of the CIE and FDE, this is the section
     76   /// to emit them into.
     77   MCSection *CompactUnwindSection;
     78 
     79   // Dwarf sections for debug info.  If a target supports debug info, these must
     80   // be set.
     81   MCSection *DwarfAbbrevSection;
     82   MCSection *DwarfInfoSection;
     83   MCSection *DwarfLineSection;
     84   MCSection *DwarfLineStrSection;
     85   MCSection *DwarfFrameSection;
     86   MCSection *DwarfPubTypesSection;
     87   const MCSection *DwarfDebugInlineSection;
     88   MCSection *DwarfStrSection;
     89   MCSection *DwarfLocSection;
     90   MCSection *DwarfARangesSection;
     91   MCSection *DwarfRangesSection;
     92   MCSection *DwarfMacinfoSection;
     93   // The pubnames section is no longer generated by default.  The generation
     94   // can be enabled by a compiler flag.
     95   MCSection *DwarfPubNamesSection;
     96 
     97   /// Accelerator table sections. DwarfDebugNamesSection is the DWARF v5
     98   /// accelerator table, while DwarfAccelNamesSection, DwarfAccelObjCSection,
     99   /// DwarfAccelNamespaceSection, DwarfAccelTypesSection are pre-DWARF v5
    100   /// extensions.
    101   MCSection *DwarfDebugNamesSection;
    102   MCSection *DwarfAccelNamesSection;
    103   MCSection *DwarfAccelObjCSection;
    104   MCSection *DwarfAccelNamespaceSection;
    105   MCSection *DwarfAccelTypesSection;
    106 
    107   // These are used for the Fission separate debug information files.
    108   MCSection *DwarfInfoDWOSection;
    109   MCSection *DwarfTypesDWOSection;
    110   MCSection *DwarfAbbrevDWOSection;
    111   MCSection *DwarfStrDWOSection;
    112   MCSection *DwarfLineDWOSection;
    113   MCSection *DwarfLocDWOSection;
    114   MCSection *DwarfStrOffDWOSection;
    115 
    116   /// The DWARF v5 string offset and address table sections.
    117   MCSection *DwarfStrOffSection;
    118   MCSection *DwarfAddrSection;
    119   /// The DWARF v5 range list section.
    120   MCSection *DwarfRnglistsSection;
    121 
    122   /// The DWARF v5 range list section for fission.
    123   MCSection *DwarfRnglistsDWOSection;
    124 
    125   // These are for Fission DWP files.
    126   MCSection *DwarfCUIndexSection;
    127   MCSection *DwarfTUIndexSection;
    128 
    129   /// Section for newer gnu pubnames.
    130   MCSection *DwarfGnuPubNamesSection;
    131   /// Section for newer gnu pubtypes.
    132   MCSection *DwarfGnuPubTypesSection;
    133 
    134   // Section for Swift AST
    135   MCSection *DwarfSwiftASTSection;
    136 
    137   MCSection *COFFDebugSymbolsSection;
    138   MCSection *COFFDebugTypesSection;
    139   MCSection *COFFGlobalTypeHashesSection;
    140 
    141   /// Extra TLS Variable Data section.
    142   ///
    143   /// If the target needs to put additional information for a TLS variable,
    144   /// it'll go here.
    145   MCSection *TLSExtraDataSection;
    146 
    147   /// Section directive for Thread Local data. ELF, MachO, COFF, and Wasm.
    148   MCSection *TLSDataSection; // Defaults to ".tdata".
    149 
    150   /// Section directive for Thread Local uninitialized data.
    151   ///
    152   /// Null if this target doesn't support a BSS section. ELF and MachO only.
    153   MCSection *TLSBSSSection; // Defaults to ".tbss".
    154 
    155   /// StackMap section.
    156   MCSection *StackMapSection;
    157 
    158   /// FaultMap section.
    159   MCSection *FaultMapSection;
    160 
    161   /// EH frame section.
    162   ///
    163   /// It is initialized on demand so it can be overwritten (with uniquing).
    164   MCSection *EHFrameSection;
    165 
    166   /// Section containing metadata on function stack sizes.
    167   MCSection *StackSizesSection;
    168   mutable DenseMap<const MCSymbol *, unsigned> StackSizesUniquing;
    169 
    170   // ELF specific sections.
    171   MCSection *DataRelROSection;
    172   MCSection *MergeableConst4Section;
    173   MCSection *MergeableConst8Section;
    174   MCSection *MergeableConst16Section;
    175   MCSection *MergeableConst32Section;
    176 
    177   // MachO specific sections.
    178 
    179   /// Section for thread local structure information.
    180   ///
    181   /// Contains the source code name of the variable, visibility and a pointer to
    182   /// the initial value (.tdata or .tbss).
    183   MCSection *TLSTLVSection; // Defaults to ".tlv".
    184 
    185   /// Section for thread local data initialization functions.
    186   const MCSection *TLSThreadInitSection; // Defaults to ".thread_init_func".
    187 
    188   MCSection *CStringSection;
    189   MCSection *UStringSection;
    190   MCSection *TextCoalSection;
    191   MCSection *ConstTextCoalSection;
    192   MCSection *ConstDataSection;
    193   MCSection *DataCoalSection;
    194   MCSection *ConstDataCoalSection;
    195   MCSection *DataCommonSection;
    196   MCSection *DataBSSSection;
    197   MCSection *FourByteConstantSection;
    198   MCSection *EightByteConstantSection;
    199   MCSection *SixteenByteConstantSection;
    200   MCSection *LazySymbolPointerSection;
    201   MCSection *NonLazySymbolPointerSection;
    202   MCSection *ThreadLocalPointerSection;
    203 
    204   /// COFF specific sections.
    205   MCSection *DrectveSection;
    206   MCSection *PDataSection;
    207   MCSection *XDataSection;
    208   MCSection *SXDataSection;
    209   MCSection *GFIDsSection;
    210 
    211 public:
    212   void InitMCObjectFileInfo(const Triple &TT, bool PIC, MCContext &ctx,
    213                             bool LargeCodeModel = false);
    214 
    215   bool getSupportsWeakOmittedEHFrame() const {
    216     return SupportsWeakOmittedEHFrame;
    217   }
    218   bool getSupportsCompactUnwindWithoutEHFrame() const {
    219     return SupportsCompactUnwindWithoutEHFrame;
    220   }
    221   bool getOmitDwarfIfHaveCompactUnwind() const {
    222     return OmitDwarfIfHaveCompactUnwind;
    223   }
    224 
    225   bool getCommDirectiveSupportsAlignment() const {
    226     return CommDirectiveSupportsAlignment;
    227   }
    228 
    229   unsigned getPersonalityEncoding() const { return PersonalityEncoding; }
    230   unsigned getLSDAEncoding() const { return LSDAEncoding; }
    231   unsigned getFDEEncoding() const { return FDECFIEncoding; }
    232   unsigned getTTypeEncoding() const { return TTypeEncoding; }
    233 
    234   unsigned getCompactUnwindDwarfEHFrameOnly() const {
    235     return CompactUnwindDwarfEHFrameOnly;
    236   }
    237 
    238   MCSection *getTextSection() const { return TextSection; }
    239   MCSection *getDataSection() const { return DataSection; }
    240   MCSection *getBSSSection() const { return BSSSection; }
    241   MCSection *getReadOnlySection() const { return ReadOnlySection; }
    242   MCSection *getLSDASection() const { return LSDASection; }
    243   MCSection *getCompactUnwindSection() const { return CompactUnwindSection; }
    244   MCSection *getDwarfAbbrevSection() const { return DwarfAbbrevSection; }
    245   MCSection *getDwarfInfoSection() const { return DwarfInfoSection; }
    246   MCSection *getDwarfLineSection() const { return DwarfLineSection; }
    247   MCSection *getDwarfLineStrSection() const { return DwarfLineStrSection; }
    248   MCSection *getDwarfFrameSection() const { return DwarfFrameSection; }
    249   MCSection *getDwarfPubNamesSection() const { return DwarfPubNamesSection; }
    250   MCSection *getDwarfPubTypesSection() const { return DwarfPubTypesSection; }
    251   MCSection *getDwarfGnuPubNamesSection() const {
    252     return DwarfGnuPubNamesSection;
    253   }
    254   MCSection *getDwarfGnuPubTypesSection() const {
    255     return DwarfGnuPubTypesSection;
    256   }
    257   const MCSection *getDwarfDebugInlineSection() const {
    258     return DwarfDebugInlineSection;
    259   }
    260   MCSection *getDwarfStrSection() const { return DwarfStrSection; }
    261   MCSection *getDwarfLocSection() const { return DwarfLocSection; }
    262   MCSection *getDwarfARangesSection() const { return DwarfARangesSection; }
    263   MCSection *getDwarfRangesSection() const { return DwarfRangesSection; }
    264   MCSection *getDwarfRnglistsSection() const { return DwarfRnglistsSection; }
    265   MCSection *getDwarfMacinfoSection() const { return DwarfMacinfoSection; }
    266 
    267   MCSection *getDwarfDebugNamesSection() const {
    268     return DwarfDebugNamesSection;
    269   }
    270   MCSection *getDwarfAccelNamesSection() const {
    271     return DwarfAccelNamesSection;
    272   }
    273   MCSection *getDwarfAccelObjCSection() const { return DwarfAccelObjCSection; }
    274   MCSection *getDwarfAccelNamespaceSection() const {
    275     return DwarfAccelNamespaceSection;
    276   }
    277   MCSection *getDwarfAccelTypesSection() const {
    278     return DwarfAccelTypesSection;
    279   }
    280   MCSection *getDwarfInfoDWOSection() const { return DwarfInfoDWOSection; }
    281   MCSection *getDwarfTypesSection(uint64_t Hash) const;
    282   MCSection *getDwarfTypesDWOSection() const { return DwarfTypesDWOSection; }
    283   MCSection *getDwarfAbbrevDWOSection() const { return DwarfAbbrevDWOSection; }
    284   MCSection *getDwarfStrDWOSection() const { return DwarfStrDWOSection; }
    285   MCSection *getDwarfLineDWOSection() const { return DwarfLineDWOSection; }
    286   MCSection *getDwarfLocDWOSection() const { return DwarfLocDWOSection; }
    287   MCSection *getDwarfStrOffDWOSection() const { return DwarfStrOffDWOSection; }
    288   MCSection *getDwarfStrOffSection() const { return DwarfStrOffSection; }
    289   MCSection *getDwarfAddrSection() const { return DwarfAddrSection; }
    290   MCSection *getDwarfRnglistsDWOSection() const {
    291     return DwarfRnglistsDWOSection;
    292   }
    293   MCSection *getDwarfCUIndexSection() const { return DwarfCUIndexSection; }
    294   MCSection *getDwarfTUIndexSection() const { return DwarfTUIndexSection; }
    295   MCSection *getDwarfSwiftASTSection() const { return DwarfSwiftASTSection; }
    296 
    297   MCSection *getCOFFDebugSymbolsSection() const {
    298     return COFFDebugSymbolsSection;
    299   }
    300   MCSection *getCOFFDebugTypesSection() const {
    301     return COFFDebugTypesSection;
    302   }
    303   MCSection *getCOFFGlobalTypeHashesSection() const {
    304     return COFFGlobalTypeHashesSection;
    305   }
    306 
    307   MCSection *getTLSExtraDataSection() const { return TLSExtraDataSection; }
    308   const MCSection *getTLSDataSection() const { return TLSDataSection; }
    309   MCSection *getTLSBSSSection() const { return TLSBSSSection; }
    310 
    311   MCSection *getStackMapSection() const { return StackMapSection; }
    312   MCSection *getFaultMapSection() const { return FaultMapSection; }
    313 
    314   MCSection *getStackSizesSection(const MCSection &TextSec) const;
    315 
    316   // ELF specific sections.
    317   MCSection *getDataRelROSection() const { return DataRelROSection; }
    318   const MCSection *getMergeableConst4Section() const {
    319     return MergeableConst4Section;
    320   }
    321   const MCSection *getMergeableConst8Section() const {
    322     return MergeableConst8Section;
    323   }
    324   const MCSection *getMergeableConst16Section() const {
    325     return MergeableConst16Section;
    326   }
    327   const MCSection *getMergeableConst32Section() const {
    328     return MergeableConst32Section;
    329   }
    330 
    331   // MachO specific sections.
    332   const MCSection *getTLSTLVSection() const { return TLSTLVSection; }
    333   const MCSection *getTLSThreadInitSection() const {
    334     return TLSThreadInitSection;
    335   }
    336   const MCSection *getCStringSection() const { return CStringSection; }
    337   const MCSection *getUStringSection() const { return UStringSection; }
    338   MCSection *getTextCoalSection() const { return TextCoalSection; }
    339   const MCSection *getConstTextCoalSection() const {
    340     return ConstTextCoalSection;
    341   }
    342   const MCSection *getConstDataSection() const { return ConstDataSection; }
    343   const MCSection *getDataCoalSection() const { return DataCoalSection; }
    344   const MCSection *getConstDataCoalSection() const {
    345     return ConstDataCoalSection;
    346   }
    347   const MCSection *getDataCommonSection() const { return DataCommonSection; }
    348   MCSection *getDataBSSSection() const { return DataBSSSection; }
    349   const MCSection *getFourByteConstantSection() const {
    350     return FourByteConstantSection;
    351   }
    352   const MCSection *getEightByteConstantSection() const {
    353     return EightByteConstantSection;
    354   }
    355   const MCSection *getSixteenByteConstantSection() const {
    356     return SixteenByteConstantSection;
    357   }
    358   MCSection *getLazySymbolPointerSection() const {
    359     return LazySymbolPointerSection;
    360   }
    361   MCSection *getNonLazySymbolPointerSection() const {
    362     return NonLazySymbolPointerSection;
    363   }
    364   MCSection *getThreadLocalPointerSection() const {
    365     return ThreadLocalPointerSection;
    366   }
    367 
    368   // COFF specific sections.
    369   MCSection *getDrectveSection() const { return DrectveSection; }
    370   MCSection *getPDataSection() const { return PDataSection; }
    371   MCSection *getXDataSection() const { return XDataSection; }
    372   MCSection *getSXDataSection() const { return SXDataSection; }
    373   MCSection *getGFIDsSection() const { return GFIDsSection; }
    374 
    375   MCSection *getEHFrameSection() {
    376     return EHFrameSection;
    377   }
    378 
    379   enum Environment { IsMachO, IsELF, IsCOFF, IsWasm };
    380   Environment getObjectFileType() const { return Env; }
    381 
    382   bool isPositionIndependent() const { return PositionIndependent; }
    383 
    384 private:
    385   Environment Env;
    386   bool PositionIndependent;
    387   MCContext *Ctx;
    388   Triple TT;
    389 
    390   void initMachOMCObjectFileInfo(const Triple &T);
    391   void initELFMCObjectFileInfo(const Triple &T, bool Large);
    392   void initCOFFMCObjectFileInfo(const Triple &T);
    393   void initWasmMCObjectFileInfo(const Triple &T);
    394 
    395 public:
    396   const Triple &getTargetTriple() const { return TT; }
    397 };
    398 
    399 } // end namespace llvm
    400 
    401 #endif
    402