1//===-- Archive.cpp - Generic LLVM archive functions ------------*- 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 implementation of the Archive and ArchiveMember
11// classes that is common to both reading and writing archives..
12//
13//===----------------------------------------------------------------------===//
14
15#include "ArchiveInternals.h"
16#include "llvm/Bitcode/ReaderWriter.h"
17#include "llvm/Module.h"
18#include "llvm/Support/FileSystem.h"
19#include "llvm/Support/MemoryBuffer.h"
20#include "llvm/Support/Process.h"
21#include "llvm/Support/system_error.h"
22#include <memory>
23#include <cstring>
24using namespace llvm;
25
26// getMemberSize - compute the actual physical size of the file member as seen
27// on disk. This isn't the size of member's payload. Use getSize() for that.
28unsigned
29ArchiveMember::getMemberSize() const {
30  // Basically its the file size plus the header size
31  unsigned result =  info.fileSize + sizeof(ArchiveMemberHeader);
32
33  // If it has a long filename, include the name length
34  if (hasLongFilename())
35    result += path.str().length() + 1;
36
37  // If its now odd lengthed, include the padding byte
38  if (result % 2 != 0 )
39    result++;
40
41  return result;
42}
43
44// This default constructor is only use by the ilist when it creates its
45// sentry node. We give it specific static values to make it stand out a bit.
46ArchiveMember::ArchiveMember()
47  : parent(0), path("--invalid--"), flags(0), data(0)
48{
49  info.user = sys::Process::GetCurrentUserId();
50  info.group = sys::Process::GetCurrentGroupId();
51  info.mode = 0777;
52  info.fileSize = 0;
53  info.modTime = sys::TimeValue::now();
54}
55
56// This is the constructor that the Archive class uses when it is building or
57// reading an archive. It just defaults a few things and ensures the parent is
58// set for the iplist. The Archive class fills in the ArchiveMember's data.
59// This is required because correctly setting the data may depend on other
60// things in the Archive.
61ArchiveMember::ArchiveMember(Archive* PAR)
62  : parent(PAR), path(), flags(0), data(0)
63{
64}
65
66// This method allows an ArchiveMember to be replaced with the data for a
67// different file, presumably as an update to the member. It also makes sure
68// the flags are reset correctly.
69bool ArchiveMember::replaceWith(const sys::Path& newFile, std::string* ErrMsg) {
70  bool Exists;
71  if (sys::fs::exists(newFile.str(), Exists) || !Exists) {
72    if (ErrMsg)
73      *ErrMsg = "Can not replace an archive member with a non-existent file";
74    return true;
75  }
76
77  data = 0;
78  path = newFile;
79
80  // SVR4 symbol tables have an empty name
81  if (path.str() == ARFILE_SVR4_SYMTAB_NAME)
82    flags |= SVR4SymbolTableFlag;
83  else
84    flags &= ~SVR4SymbolTableFlag;
85
86  // BSD4.4 symbol tables have a special name
87  if (path.str() == ARFILE_BSD4_SYMTAB_NAME)
88    flags |= BSD4SymbolTableFlag;
89  else
90    flags &= ~BSD4SymbolTableFlag;
91
92  // LLVM symbol tables have a very specific name
93  if (path.str() == ARFILE_LLVM_SYMTAB_NAME)
94    flags |= LLVMSymbolTableFlag;
95  else
96    flags &= ~LLVMSymbolTableFlag;
97
98  // String table name
99  if (path.str() == ARFILE_STRTAB_NAME)
100    flags |= StringTableFlag;
101  else
102    flags &= ~StringTableFlag;
103
104  // If it has a slash then it has a path
105  bool hasSlash = path.str().find('/') != std::string::npos;
106  if (hasSlash)
107    flags |= HasPathFlag;
108  else
109    flags &= ~HasPathFlag;
110
111  // If it has a slash or its over 15 chars then its a long filename format
112  if (hasSlash || path.str().length() > 15)
113    flags |= HasLongFilenameFlag;
114  else
115    flags &= ~HasLongFilenameFlag;
116
117  // Get the signature and status info
118  const char* signature = (const char*) data;
119  SmallString<4> magic;
120  if (!signature) {
121    sys::fs::get_magic(path.str(), magic.capacity(), magic);
122    signature = magic.c_str();
123    const sys::FileStatus *FSinfo = path.getFileStatus(false, ErrMsg);
124    if (FSinfo)
125      info = *FSinfo;
126    else
127      return true;
128  }
129
130  // Determine what kind of file it is.
131  switch (sys::IdentifyFileType(signature,4)) {
132    case sys::Bitcode_FileType:
133      flags |= BitcodeFlag;
134      break;
135    default:
136      flags &= ~BitcodeFlag;
137      break;
138  }
139  return false;
140}
141
142// Archive constructor - this is the only constructor that gets used for the
143// Archive class. Everything else (default,copy) is deprecated. This just
144// initializes and maps the file into memory, if requested.
145Archive::Archive(const sys::Path& filename, LLVMContext& C)
146  : archPath(filename), members(), mapfile(0), base(0), symTab(), strtab(),
147    symTabSize(0), firstFileOffset(0), modules(), foreignST(0), Context(C) {
148}
149
150bool
151Archive::mapToMemory(std::string* ErrMsg) {
152  OwningPtr<MemoryBuffer> File;
153  if (error_code ec = MemoryBuffer::getFile(archPath.c_str(), File)) {
154    if (ErrMsg)
155      *ErrMsg = ec.message();
156    return true;
157  }
158  mapfile = File.take();
159  base = mapfile->getBufferStart();
160  return false;
161}
162
163void Archive::cleanUpMemory() {
164  // Shutdown the file mapping
165  delete mapfile;
166  mapfile = 0;
167  base = 0;
168
169  // Forget the entire symbol table
170  symTab.clear();
171  symTabSize = 0;
172
173  firstFileOffset = 0;
174
175  // Free the foreign symbol table member
176  if (foreignST) {
177    delete foreignST;
178    foreignST = 0;
179  }
180
181  // Delete any Modules and ArchiveMember's we've allocated as a result of
182  // symbol table searches.
183  for (ModuleMap::iterator I=modules.begin(), E=modules.end(); I != E; ++I ) {
184    delete I->second.first;
185    delete I->second.second;
186  }
187}
188
189// Archive destructor - just clean up memory
190Archive::~Archive() {
191  cleanUpMemory();
192}
193
194
195
196static void getSymbols(Module*M, std::vector<std::string>& symbols) {
197  // Loop over global variables
198  for (Module::global_iterator GI = M->global_begin(), GE=M->global_end(); GI != GE; ++GI)
199    if (!GI->isDeclaration() && !GI->hasLocalLinkage())
200      if (!GI->getName().empty())
201        symbols.push_back(GI->getName());
202
203  // Loop over functions
204  for (Module::iterator FI = M->begin(), FE = M->end(); FI != FE; ++FI)
205    if (!FI->isDeclaration() && !FI->hasLocalLinkage())
206      if (!FI->getName().empty())
207        symbols.push_back(FI->getName());
208
209  // Loop over aliases
210  for (Module::alias_iterator AI = M->alias_begin(), AE = M->alias_end();
211       AI != AE; ++AI) {
212    if (AI->hasName())
213      symbols.push_back(AI->getName());
214  }
215}
216
217// Get just the externally visible defined symbols from the bitcode
218bool llvm::GetBitcodeSymbols(const sys::Path& fName,
219                             LLVMContext& Context,
220                             std::vector<std::string>& symbols,
221                             std::string* ErrMsg) {
222  OwningPtr<MemoryBuffer> Buffer;
223  if (error_code ec = MemoryBuffer::getFileOrSTDIN(fName.c_str(), Buffer)) {
224    if (ErrMsg) *ErrMsg = "Could not open file '" + fName.str() + "'" + ": "
225                        + ec.message();
226    return true;
227  }
228
229  Module *M = ParseBitcodeFile(Buffer.get(), Context, ErrMsg);
230  if (!M)
231    return true;
232
233  // Get the symbols
234  getSymbols(M, symbols);
235
236  // Done with the module.
237  delete M;
238  return true;
239}
240
241Module*
242llvm::GetBitcodeSymbols(const char *BufPtr, unsigned Length,
243                        const std::string& ModuleID,
244                        LLVMContext& Context,
245                        std::vector<std::string>& symbols,
246                        std::string* ErrMsg) {
247  // Get the module.
248  OwningPtr<MemoryBuffer> Buffer(
249    MemoryBuffer::getMemBufferCopy(StringRef(BufPtr, Length),ModuleID.c_str()));
250
251  Module *M = ParseBitcodeFile(Buffer.get(), Context, ErrMsg);
252  if (!M)
253    return 0;
254
255  // Get the symbols
256  getSymbols(M, symbols);
257
258  // Done with the module. Note that it's the caller's responsibility to delete
259  // the Module.
260  return M;
261}
262