1 //===- ConstantPools.cpp - ConstantPool class --*- 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 implements the ConstantPool and AssemblerConstantPools classes. 11 // 12 //===----------------------------------------------------------------------===// 13 #include "llvm/ADT/MapVector.h" 14 #include "llvm/MC/ConstantPools.h" 15 #include "llvm/MC/MCContext.h" 16 #include "llvm/MC/MCExpr.h" 17 #include "llvm/MC/MCStreamer.h" 18 19 using namespace llvm; 20 // 21 // ConstantPool implementation 22 // 23 // Emit the contents of the constant pool using the provided streamer. 24 void ConstantPool::emitEntries(MCStreamer &Streamer) { 25 if (Entries.empty()) 26 return; 27 Streamer.EmitDataRegion(MCDR_DataRegion); 28 for (EntryVecTy::const_iterator I = Entries.begin(), E = Entries.end(); 29 I != E; ++I) { 30 Streamer.EmitCodeAlignment(I->Size); // align naturally 31 Streamer.EmitLabel(I->Label); 32 Streamer.EmitValue(I->Value, I->Size); 33 } 34 Streamer.EmitDataRegion(MCDR_DataRegionEnd); 35 Entries.clear(); 36 } 37 38 const MCExpr *ConstantPool::addEntry(const MCExpr *Value, MCContext &Context, 39 unsigned Size) { 40 MCSymbol *CPEntryLabel = Context.createTempSymbol(); 41 42 Entries.push_back(ConstantPoolEntry(CPEntryLabel, Value, Size)); 43 return MCSymbolRefExpr::Create(CPEntryLabel, Context); 44 } 45 46 bool ConstantPool::empty() { return Entries.empty(); } 47 48 // 49 // AssemblerConstantPools implementation 50 // 51 ConstantPool *AssemblerConstantPools::getConstantPool(MCSection *Section) { 52 ConstantPoolMapTy::iterator CP = ConstantPools.find(Section); 53 if (CP == ConstantPools.end()) 54 return nullptr; 55 56 return &CP->second; 57 } 58 59 ConstantPool & 60 AssemblerConstantPools::getOrCreateConstantPool(MCSection *Section) { 61 return ConstantPools[Section]; 62 } 63 64 static void emitConstantPool(MCStreamer &Streamer, MCSection *Section, 65 ConstantPool &CP) { 66 if (!CP.empty()) { 67 Streamer.SwitchSection(Section); 68 CP.emitEntries(Streamer); 69 } 70 } 71 72 void AssemblerConstantPools::emitAll(MCStreamer &Streamer) { 73 // Dump contents of assembler constant pools. 74 for (ConstantPoolMapTy::iterator CPI = ConstantPools.begin(), 75 CPE = ConstantPools.end(); 76 CPI != CPE; ++CPI) { 77 MCSection *Section = CPI->first; 78 ConstantPool &CP = CPI->second; 79 80 emitConstantPool(Streamer, Section, CP); 81 } 82 } 83 84 void AssemblerConstantPools::emitForCurrentSection(MCStreamer &Streamer) { 85 MCSection *Section = Streamer.getCurrentSection().first; 86 if (ConstantPool *CP = getConstantPool(Section)) { 87 emitConstantPool(Streamer, Section, *CP); 88 } 89 } 90 91 const MCExpr *AssemblerConstantPools::addEntry(MCStreamer &Streamer, 92 const MCExpr *Expr, 93 unsigned Size) { 94 MCSection *Section = Streamer.getCurrentSection().first; 95 return getOrCreateConstantPool(Section).addEntry(Expr, Streamer.getContext(), 96 Size); 97 } 98