lib/Archive/Archive.cpp

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