lib/Target/PowerPC/PPCTargetAsmInfo.cpp

   1 //===-- PPCTargetAsmInfo.cpp - PPC asm properties ---------------*- 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 contains the declarations of the DarwinTargetAsmInfo properties.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "PPCTargetAsmInfo.h"
  15 #include "PPCTargetMachine.h"
  16 #include "llvm/Function.h"
  17 #include "llvm/Support/Dwarf.h"
  18
  19 using namespace llvm;
  20 using namespace llvm::dwarf;
  21
  22 PPCDarwinTargetAsmInfo::PPCDarwinTargetAsmInfo(const PPCTargetMachine &TM):
  23   PPCTargetAsmInfo<DarwinTargetAsmInfo>(TM) {
  24   PCSymbol = ".";
  25   CommentString = ";";
  26   GlobalPrefix = "_";
  27   PrivateGlobalPrefix = "L";
  28   LessPrivateGlobalPrefix = "l";
  29   StringConstantPrefix = "\1LC";
  30   ConstantPoolSection = "\t.const\t";
  31   JumpTableDataSection = ".const";
  32   CStringSection = "\t.cstring";
  33   if (TM.getRelocationModel() == Reloc::Static) {
  34     StaticCtorsSection = ".constructor";
  35     StaticDtorsSection = ".destructor";
  36   } else {
  37     StaticCtorsSection = ".mod_init_func";
  38     StaticDtorsSection = ".mod_term_func";
  39   }
  40   HasSingleParameterDotFile = false;
  41   SwitchToSectionDirective = "\t.section ";
  42   UsedDirective = "\t.no_dead_strip\t";
  43   WeakDefDirective = "\t.weak_definition ";
  44   WeakRefDirective = "\t.weak_reference ";
  45   HiddenDirective = "\t.private_extern ";
  46   SupportsExceptionHandling = true;
  47   NeedsIndirectEncoding = true;
  48   NeedsSet = true;
  49   BSSSection = 0;
  50
  51   DwarfEHFrameSection =
  52   ".section __TEXT,__eh_frame,coalesced,no_toc+strip_static_syms+live_support";
  53   DwarfExceptionSection = ".section __DATA,__gcc_except_tab";
  54   GlobalEHDirective = "\t.globl\t";
  55   SupportsWeakOmittedEHFrame = false;
  56
  57   DwarfAbbrevSection = ".section __DWARF,__debug_abbrev,regular,debug";
  58   DwarfInfoSection = ".section __DWARF,__debug_info,regular,debug";
  59   DwarfLineSection = ".section __DWARF,__debug_line,regular,debug";
  60   DwarfFrameSection = ".section __DWARF,__debug_frame,regular,debug";
  61   DwarfPubNamesSection = ".section __DWARF,__debug_pubnames,regular,debug";
  62   DwarfPubTypesSection = ".section __DWARF,__debug_pubtypes,regular,debug";
  63   DwarfStrSection = ".section __DWARF,__debug_str,regular,debug";
  64   DwarfLocSection = ".section __DWARF,__debug_loc,regular,debug";
  65   DwarfARangesSection = ".section __DWARF,__debug_aranges,regular,debug";
  66   DwarfRangesSection = ".section __DWARF,__debug_ranges,regular,debug";
  67   DwarfMacInfoSection = ".section __DWARF,__debug_macinfo,regular,debug";
  68
  69   // In non-PIC modes, emit a special label before jump tables so that the
  70   // linker can perform more accurate dead code stripping.
  71   if (TM.getRelocationModel() != Reloc::PIC_) {
  72     // Emit a local label that is preserved until the linker runs.
  73     JumpTableSpecialLabelPrefix = "l";
  74   }
  75 }
  76
  77 /// PreferredEHDataFormat - This hook allows the target to select data
  78 /// format used for encoding pointers in exception handling data. Reason is
  79 /// 0 for data, 1 for code labels, 2 for function pointers. Global is true
  80 /// if the symbol can be relocated.
  81 unsigned
  82 PPCDarwinTargetAsmInfo::PreferredEHDataFormat(DwarfEncoding::Target Reason,
  83                                               bool Global) const {
  84   if (Reason == DwarfEncoding::Functions && Global)
  85     return (DW_EH_PE_pcrel | DW_EH_PE_indirect | DW_EH_PE_sdata4);
  86   else if (Reason == DwarfEncoding::CodeLabels || !Global)
  87     return DW_EH_PE_pcrel;
  88   else
  89     return DW_EH_PE_absptr;
  90 }
  91
  92 const char *
  93 PPCDarwinTargetAsmInfo::getEHGlobalPrefix() const
  94 {
  95   const PPCSubtarget* Subtarget = &TM.getSubtarget<PPCSubtarget>();
  96   if (Subtarget->getDarwinVers() > 9)
  97     return PrivateGlobalPrefix;
  98   else
  99     return "";
 100 }
 101
 102 PPCLinuxTargetAsmInfo::PPCLinuxTargetAsmInfo(const PPCTargetMachine &TM) :
 103   PPCTargetAsmInfo<ELFTargetAsmInfo>(TM) {
 104   CommentString = "#";
 105   GlobalPrefix = "";
 106   PrivateGlobalPrefix = ".L";
 107   ConstantPoolSection = "\t.section .rodata.cst4\t";
 108   JumpTableDataSection = ".section .rodata.cst4";
 109   CStringSection = ".rodata.str";
 110   StaticCtorsSection = ".section\t.ctors,\"aw\",@progbits";
 111   StaticDtorsSection = ".section\t.dtors,\"aw\",@progbits";
 112   UsedDirective = "\t# .no_dead_strip\t";
 113   WeakRefDirective = "\t.weak\t";
 114   BSSSection = "\t.section\t\".sbss\",\"aw\",@nobits";
 115
 116   // PPC/Linux normally uses named section for BSS.
 117   BSSSection_  = getNamedSection("\t.bss",
 118                                  SectionFlags::Writeable | SectionFlags::BSS,
 119                                  /* Override */ true);
 120
 121   // Debug Information
 122   AbsoluteDebugSectionOffsets = true;
 123   SupportsDebugInformation = true;
 124   DwarfAbbrevSection =  "\t.section\t.debug_abbrev,\"\",@progbits";
 125   DwarfInfoSection =    "\t.section\t.debug_info,\"\",@progbits";
 126   DwarfLineSection =    "\t.section\t.debug_line,\"\",@progbits";
 127   DwarfFrameSection =   "\t.section\t.debug_frame,\"\",@progbits";
 128   DwarfPubNamesSection ="\t.section\t.debug_pubnames,\"\",@progbits";
 129   DwarfPubTypesSection ="\t.section\t.debug_pubtypes,\"\",@progbits";
 130   DwarfStrSection =     "\t.section\t.debug_str,\"\",@progbits";
 131   DwarfLocSection =     "\t.section\t.debug_loc,\"\",@progbits";
 132   DwarfARangesSection = "\t.section\t.debug_aranges,\"\",@progbits";
 133   DwarfRangesSection =  "\t.section\t.debug_ranges,\"\",@progbits";
 134   DwarfMacInfoSection = "\t.section\t.debug_macinfo,\"\",@progbits";
 135
 136   PCSymbol = ".";
 137
 138   // Set up DWARF directives
 139   HasLEB128 = true;  // Target asm supports leb128 directives (little-endian)
 140
 141   // Exceptions handling
 142   if (!TM.getSubtargetImpl()->isPPC64())
 143     SupportsExceptionHandling = true;
 144   AbsoluteEHSectionOffsets = false;
 145   DwarfEHFrameSection = "\t.section\t.eh_frame,\"aw\",@progbits";
 146   DwarfExceptionSection = "\t.section\t.gcc_except_table,\"a\",@progbits";
 147 }
 148
 149 /// PreferredEHDataFormat - This hook allows the target to select data
 150 /// format used for encoding pointers in exception handling data. Reason is
 151 /// 0 for data, 1 for code labels, 2 for function pointers. Global is true
 152 /// if the symbol can be relocated.
 153 unsigned
 154 PPCLinuxTargetAsmInfo::PreferredEHDataFormat(DwarfEncoding::Target Reason,
 155                                              bool Global) const {
 156   // We really need to write something here.
 157   return TargetAsmInfo::PreferredEHDataFormat(Reason, Global);
 158 }
 159
 160 // Instantiate default implementation.
 161 TEMPLATE_INSTANTIATION(class PPCTargetAsmInfo<TargetAsmInfo>);