Line data    Source code

       1             : //===- llvm/CodeGen/AddressPool.cpp - Dwarf Debug Framework ---------------===//
       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             : #include "AddressPool.h"
      11             : #include "llvm/ADT/SmallVector.h"
      12             : #include "llvm/CodeGen/AsmPrinter.h"
      13             : #include "llvm/IR/DataLayout.h"
      14             : #include "llvm/MC/MCStreamer.h"
      15             : #include "llvm/Target/TargetLoweringObjectFile.h"
      16             : #include <utility>
      17             : 
      18             : using namespace llvm;
      19             : 
      20         100 : unsigned AddressPool::getIndex(const MCSymbol *Sym, bool TLS) {
      21         100 :   HasBeenUsed = true;
      22             :   auto IterBool =
      23         200 :       Pool.insert(std::make_pair(Sym, AddressPoolEntry(Pool.size(), TLS)));
      24         100 :   return IterBool.first->second.Number;
      25             : }
      26             : 
      27             : 
      28           6 : void AddressPool::emitHeader(AsmPrinter &Asm, MCSection *Section) {
      29           6 :   static const uint8_t AddrSize = Asm.getDataLayout().getPointerSize();
      30             :   uint64_t Length = sizeof(uint16_t) // version
      31             :                   + sizeof(uint8_t)  // address_size
      32             :                   + sizeof(uint8_t)  // segment_selector_size
      33           6 :                   + AddrSize * Pool.size(); // entries
      34           6 :   Asm.emitInt32(Length); // TODO: Support DWARF64 format.
      35           6 :   Asm.emitInt16(Asm.getDwarfVersion());
      36           6 :   Asm.emitInt8(AddrSize);
      37           6 :   Asm.emitInt8(0); // TODO: Support non-zero segment_selector_size.
      38           6 : }
      39             : 
      40             : // Emit addresses into the section given.
      41          37 : void AddressPool::emit(AsmPrinter &Asm, MCSection *AddrSection) {
      42             :   // Start the dwarf addr section.
      43          37 :   Asm.OutStreamer->SwitchSection(AddrSection);
      44             : 
      45          37 :   if (Asm.getDwarfVersion() >= 5)
      46           6 :     emitHeader(Asm, AddrSection);
      47             : 
      48             :   // Define the symbol that marks the start of the contribution.
      49             :   // It is referenced via DW_AT_addr_base.
      50          37 :   Asm.OutStreamer->EmitLabel(AddressTableBaseSym);
      51             : 
      52          37 :   if (Pool.empty())
      53           3 :     return;
      54             : 
      55             :   // Order the address pool entries by ID
      56          34 :   SmallVector<const MCExpr *, 64> Entries(Pool.size());
      57             : 
      58         120 :   for (const auto &I : Pool)
      59         172 :     Entries[I.second.Number] =
      60          86 :         I.second.TLS
      61          86 :             ? Asm.getObjFileLowering().getDebugThreadLocalSymbol(I.first)
      62          84 :             : MCSymbolRefExpr::create(I.first, Asm.OutContext);
      63             : 
      64         120 :   for (const MCExpr *Entry : Entries)
      65          86 :     Asm.OutStreamer->EmitValue(Entry, Asm.getDataLayout().getPointerSize());
      66             : }