1 //===- IRObjectFile.cpp - IR object file implementation ---------*- 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 // Part of the IRObjectFile class implementation.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/Bitcode/ReaderWriter.h"
15 #include "llvm/IR/LLVMContext.h"
16 #include "llvm/IR/GVMaterializer.h"
17 #include "llvm/IR/Mangler.h"
18 #include "llvm/IR/Module.h"
19 #include "llvm/Object/IRObjectFile.h"
20 #include "llvm/Support/MemoryBuffer.h"
21 #include "llvm/Support/raw_ostream.h"
22 using namespace llvm;
23 using namespace object;
24 
25 IRObjectFile::IRObjectFile(std::unique_ptr<MemoryBuffer> Object,
26                            std::error_code &EC, LLVMContext &Context)
27     : SymbolicFile(Binary::ID_IR, std::move(Object)) {
28   ErrorOr<Module *> MOrErr = getLazyBitcodeModule(Data.get(), Context);
29   if ((EC = MOrErr.getError()))
30     return;
31 
32   M.reset(MOrErr.get());
33 
34   // If we have a DataLayout, setup a mangler.
35   const DataLayout *DL = M->getDataLayout();
36   if (!DL)
37     return;
38 
39   Mang.reset(new Mangler(DL));
40 }
41 
42 IRObjectFile::~IRObjectFile() { M->getMaterializer()->releaseBuffer(); }
43 
44 static const GlobalValue &getGV(DataRefImpl &Symb) {
45   return *reinterpret_cast<GlobalValue*>(Symb.p & ~uintptr_t(3));
46 }
47 
48 static uintptr_t skipEmpty(Module::const_alias_iterator I, const Module &M) {
49   if (I == M.alias_end())
50     return 3;
51   const GlobalValue *GV = &*I;
52   return reinterpret_cast<uintptr_t>(GV) | 2;
53 }
54 
55 static uintptr_t skipEmpty(Module::const_global_iterator I, const Module &M) {
56   if (I == M.global_end())
57     return skipEmpty(M.alias_begin(), M);
58   const GlobalValue *GV = &*I;
59   return reinterpret_cast<uintptr_t>(GV) | 1;
60 }
61 
62 static uintptr_t skipEmpty(Module::const_iterator I, const Module &M) {
63   if (I == M.end())
64     return skipEmpty(M.global_begin(), M);
65   const GlobalValue *GV = &*I;
66   return reinterpret_cast<uintptr_t>(GV) | 0;
67 }
68 
69 void IRObjectFile::moveSymbolNext(DataRefImpl &Symb) const {
70   const GlobalValue *GV = &getGV(Symb);
71   const Module &M = *GV->getParent();
72   uintptr_t Res;
73   switch (Symb.p & 3) {
74   case 0: {
75     Module::const_iterator Iter(static_cast<const Function*>(GV));
76     ++Iter;
77     Res = skipEmpty(Iter, M);
78     break;
79   }
80   case 1: {
81     Module::const_global_iterator Iter(static_cast<const GlobalVariable*>(GV));
82     ++Iter;
83     Res = skipEmpty(Iter, M);
84     break;
85   }
86   case 2: {
87     Module::const_alias_iterator Iter(static_cast<const GlobalAlias*>(GV));
88     ++Iter;
89     Res = skipEmpty(Iter, M);
90     break;
91   }
92   case 3:
93     llvm_unreachable("Invalid symbol reference");
94   }
95 
96   Symb.p = Res;
97 }
98 
99 std::error_code IRObjectFile::printSymbolName(raw_ostream &OS,
100                                               DataRefImpl Symb) const {
101   const GlobalValue &GV = getGV(Symb);
102 
103   if (Mang)
104     Mang->getNameWithPrefix(OS, &GV, false);
105   else
106     OS << GV.getName();
107 
108   return object_error::success;
109 }
110 
111 static bool isDeclaration(const GlobalValue &V) {
112   if (V.hasAvailableExternallyLinkage())
113     return true;
114 
115   if (V.isMaterializable())
116     return false;
117 
118   return V.isDeclaration();
119 }
120 
121 uint32_t IRObjectFile::getSymbolFlags(DataRefImpl Symb) const {
122   const GlobalValue &GV = getGV(Symb);
123 
124   uint32_t Res = BasicSymbolRef::SF_None;
125   if (isDeclaration(GV))
126     Res |= BasicSymbolRef::SF_Undefined;
127   if (GV.hasPrivateLinkage())
128     Res |= BasicSymbolRef::SF_FormatSpecific;
129   if (!GV.hasLocalLinkage())
130     Res |= BasicSymbolRef::SF_Global;
131   if (GV.hasCommonLinkage())
132     Res |= BasicSymbolRef::SF_Common;
133   if (GV.hasLinkOnceLinkage() || GV.hasWeakLinkage())
134     Res |= BasicSymbolRef::SF_Weak;
135 
136   return Res;
137 }
138 
139 const GlobalValue &IRObjectFile::getSymbolGV(DataRefImpl Symb) const {
140   const GlobalValue &GV = getGV(Symb);
141   return GV;
142 }
143 
144 basic_symbol_iterator IRObjectFile::symbol_begin_impl() const {
145   Module::const_iterator I = M->begin();
146   DataRefImpl Ret;
147   Ret.p = skipEmpty(I, *M);
148   return basic_symbol_iterator(BasicSymbolRef(Ret, this));
149 }
150 
151 basic_symbol_iterator IRObjectFile::symbol_end_impl() const {
152   DataRefImpl Ret;
153   Ret.p = 3;
154   return basic_symbol_iterator(BasicSymbolRef(Ret, this));
155 }
156 
157 ErrorOr<SymbolicFile *> llvm::object::SymbolicFile::createIRObjectFile(
158     std::unique_ptr<MemoryBuffer> Object, LLVMContext &Context) {
159   std::error_code EC;
160   std::unique_ptr<IRObjectFile> Ret(
161       new IRObjectFile(std::move(Object), EC, Context));
162   if (EC)
163     return EC;
164   return Ret.release();
165 }
166