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.
emitEntries(MCStreamer & Streamer)24 void ConstantPool::emitEntries(MCStreamer &Streamer) {
25 if (Entries.empty())
26 return;
27 Streamer.EmitDataRegion(MCDR_DataRegion);
28 for (const ConstantPoolEntry &Entry : Entries) {
29 Streamer.EmitCodeAlignment(Entry.Size); // align naturally
30 Streamer.EmitLabel(Entry.Label);
31 Streamer.EmitValue(Entry.Value, Entry.Size, Entry.Loc);
32 }
33 Streamer.EmitDataRegion(MCDR_DataRegionEnd);
34 Entries.clear();
35 }
36
addEntry(const MCExpr * Value,MCContext & Context,unsigned Size,SMLoc Loc)37 const MCExpr *ConstantPool::addEntry(const MCExpr *Value, MCContext &Context,
38 unsigned Size, SMLoc Loc) {
39 MCSymbol *CPEntryLabel = Context.createTempSymbol();
40
41 Entries.push_back(ConstantPoolEntry(CPEntryLabel, Value, Size, Loc));
42 return MCSymbolRefExpr::create(CPEntryLabel, Context);
43 }
44
empty()45 bool ConstantPool::empty() { return Entries.empty(); }
46
47 //
48 // AssemblerConstantPools implementation
49 //
getConstantPool(MCSection * Section)50 ConstantPool *AssemblerConstantPools::getConstantPool(MCSection *Section) {
51 ConstantPoolMapTy::iterator CP = ConstantPools.find(Section);
52 if (CP == ConstantPools.end())
53 return nullptr;
54
55 return &CP->second;
56 }
57
58 ConstantPool &
getOrCreateConstantPool(MCSection * Section)59 AssemblerConstantPools::getOrCreateConstantPool(MCSection *Section) {
60 return ConstantPools[Section];
61 }
62
emitConstantPool(MCStreamer & Streamer,MCSection * Section,ConstantPool & CP)63 static void emitConstantPool(MCStreamer &Streamer, MCSection *Section,
64 ConstantPool &CP) {
65 if (!CP.empty()) {
66 Streamer.SwitchSection(Section);
67 CP.emitEntries(Streamer);
68 }
69 }
70
emitAll(MCStreamer & Streamer)71 void AssemblerConstantPools::emitAll(MCStreamer &Streamer) {
72 // Dump contents of assembler constant pools.
73 for (auto &CPI : ConstantPools) {
74 MCSection *Section = CPI.first;
75 ConstantPool &CP = CPI.second;
76
77 emitConstantPool(Streamer, Section, CP);
78 }
79 }
80
emitForCurrentSection(MCStreamer & Streamer)81 void AssemblerConstantPools::emitForCurrentSection(MCStreamer &Streamer) {
82 MCSection *Section = Streamer.getCurrentSection().first;
83 if (ConstantPool *CP = getConstantPool(Section)) {
84 emitConstantPool(Streamer, Section, *CP);
85 }
86 }
87
addEntry(MCStreamer & Streamer,const MCExpr * Expr,unsigned Size,SMLoc Loc)88 const MCExpr *AssemblerConstantPools::addEntry(MCStreamer &Streamer,
89 const MCExpr *Expr,
90 unsigned Size, SMLoc Loc) {
91 MCSection *Section = Streamer.getCurrentSection().first;
92 return getOrCreateConstantPool(Section).addEntry(Expr, Streamer.getContext(),
93 Size, Loc);
94 }
95