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/ModuleProvider.h"
  18 #include "llvm/Module.h"
  19 #include "llvm/Support/MemoryBuffer.h"
  20 #include "llvm/System/Process.h"
  21 #include <memory>
  22 #include <cstring>
  23 using namespace llvm;
  24
  25 // getMemberSize - compute the actual physical size of the file member as seen
  26 // on disk. This isn't the size of member's payload. Use getSize() for that.
  27 unsigned
  28 ArchiveMember::getMemberSize() const {
  29   // Basically its the file size plus the header size
  30   unsigned result =  info.fileSize + sizeof(ArchiveMemberHeader);
  31
  32   // If it has a long filename, include the name length
  33   if (hasLongFilename())
  34     result += path.toString().length() + 1;
  35
  36   // If its now odd lengthed, include the padding byte
  37   if (result % 2 != 0 )
  38     result++;
  39
  40   return result;
  41 }
  42
  43 // This default constructor is only use by the ilist when it creates its
  44 // sentry node. We give it specific static values to make it stand out a bit.
  45 ArchiveMember::ArchiveMember()
  46   : parent(0), path("--invalid--"), flags(0), data(0)
  47 {
  48   info.user = sys::Process::GetCurrentUserId();
  49   info.group = sys::Process::GetCurrentGroupId();
  50   info.mode = 0777;
  51   info.fileSize = 0;
  52   info.modTime = sys::TimeValue::now();
  53 }
  54
  55 // This is the constructor that the Archive class uses when it is building or
  56 // reading an archive. It just defaults a few things and ensures the parent is
  57 // set for the iplist. The Archive class fills in the ArchiveMember's data.
  58 // This is required because correctly setting the data may depend on other
  59 // things in the Archive.
  60 ArchiveMember::ArchiveMember(Archive* PAR)
  61   : parent(PAR), path(), flags(0), data(0)
  62 {
  63 }
  64
  65 // This method allows an ArchiveMember to be replaced with the data for a
  66 // different file, presumably as an update to the member. It also makes sure
  67 // the flags are reset correctly.
  68 bool ArchiveMember::replaceWith(const sys::Path& newFile, std::string* ErrMsg) {
  69   if (!newFile.exists()) {
  70     if (ErrMsg)
  71       *ErrMsg = "Can not replace an archive member with a non-existent file";
  72     return true;
  73   }
  74
  75   data = 0;
  76   path = newFile;
  77
  78   // SVR4 symbol tables have an empty name
  79   if (path.toString() == ARFILE_SVR4_SYMTAB_NAME)
  80     flags |= SVR4SymbolTableFlag;
  81   else
  82     flags &= ~SVR4SymbolTableFlag;
  83
  84   // BSD4.4 symbol tables have a special name
  85   if (path.toString() == ARFILE_BSD4_SYMTAB_NAME)
  86     flags |= BSD4SymbolTableFlag;
  87   else
  88     flags &= ~BSD4SymbolTableFlag;
  89
  90   // LLVM symbol tables have a very specific name
  91   if (path.toString() == ARFILE_LLVM_SYMTAB_NAME)
  92     flags |= LLVMSymbolTableFlag;
  93   else
  94     flags &= ~LLVMSymbolTableFlag;
  95
  96   // String table name
  97   if (path.toString() == ARFILE_STRTAB_NAME)
  98     flags |= StringTableFlag;
  99   else
 100     flags &= ~StringTableFlag;
 101
 102   // If it has a slash then it has a path
 103   bool hasSlash = path.toString().find('/') != std::string::npos;
 104   if (hasSlash)
 105     flags |= HasPathFlag;
 106   else
 107     flags &= ~HasPathFlag;
 108
 109   // If it has a slash or its over 15 chars then its a long filename format
 110   if (hasSlash || path.toString().length() > 15)
 111     flags |= HasLongFilenameFlag;
 112   else
 113     flags &= ~HasLongFilenameFlag;
 114
 115   // Get the signature and status info
 116   const char* signature = (const char*) data;
 117   std::string magic;
 118   if (!signature) {
 119     path.getMagicNumber(magic,4);
 120     signature = magic.c_str();
 121     std::string err;
 122     const sys::FileStatus *FSinfo = path.getFileStatus(false, ErrMsg);
 123     if (FSinfo)
 124       info = *FSinfo;
 125     else
 126       return true;
 127   }
 128
 129   // Determine what kind of file it is.
 130   switch (sys::IdentifyFileType(signature,4)) {
 131     case sys::Bitcode_FileType:
 132       flags |= BitcodeFlag;
 133       break;
 134     default:
 135       flags &= ~BitcodeFlag;
 136       break;
 137   }
 138   return false;
 139 }
 140
 141 // Archive constructor - this is the only constructor that gets used for the
 142 // Archive class. Everything else (default,copy) is deprecated. This just
 143 // initializes and maps the file into memory, if requested.
 144 Archive::Archive(const sys::Path& filename, LLVMContext& C)
 145   : archPath(filename), members(), mapfile(0), base(0), symTab(), strtab(),
 146     symTabSize(0), firstFileOffset(0), modules(), foreignST(0), Context(C) {
 147 }
 148
 149 bool
 150 Archive::mapToMemory(std::string* ErrMsg) {
 151   mapfile = MemoryBuffer::getFile(archPath.c_str(), ErrMsg);
 152   if (mapfile == 0)
 153     return true;
 154   base = mapfile->getBufferStart();
 155   return false;
 156 }
 157
 158 void Archive::cleanUpMemory() {
 159   // Shutdown the file mapping
 160   delete mapfile;
 161   mapfile = 0;
 162   base = 0;
 163
 164   // Forget the entire symbol table
 165   symTab.clear();
 166   symTabSize = 0;
 167
 168   firstFileOffset = 0;
 169
 170   // Free the foreign symbol table member
 171   if (foreignST) {
 172     delete foreignST;
 173     foreignST = 0;
 174   }
 175
 176   // Delete any ModuleProviders and ArchiveMember's we've allocated as a result
 177   // of symbol table searches.
 178   for (ModuleMap::iterator I=modules.begin(), E=modules.end(); I != E; ++I ) {
 179     delete I->second.first;
 180     delete I->second.second;
 181   }
 182 }
 183
 184 // Archive destructor - just clean up memory
 185 Archive::~Archive() {
 186   cleanUpMemory();
 187 }
 188
 189
 190
 191 static void getSymbols(Module*M, std::vector<std::string>& symbols) {
 192   // Loop over global variables
 193   for (Module::global_iterator GI = M->global_begin(), GE=M->global_end(); GI != GE; ++GI)
 194     if (!GI->isDeclaration() && !GI->hasLocalLinkage())
 195       if (!GI->getName().empty())
 196         symbols.push_back(GI->getName());
 197
 198   // Loop over functions
 199   for (Module::iterator FI = M->begin(), FE = M->end(); FI != FE; ++FI)
 200     if (!FI->isDeclaration() && !FI->hasLocalLinkage())
 201       if (!FI->getName().empty())
 202         symbols.push_back(FI->getName());
 203
 204   // Loop over aliases
 205   for (Module::alias_iterator AI = M->alias_begin(), AE = M->alias_end();
 206        AI != AE; ++AI) {
 207     if (AI->hasName())
 208       symbols.push_back(AI->getName());
 209   }
 210 }
 211
 212 // Get just the externally visible defined symbols from the bitcode
 213 bool llvm::GetBitcodeSymbols(const sys::Path& fName,
 214                              LLVMContext& Context,
 215                              std::vector<std::string>& symbols,
 216                              std::string* ErrMsg) {
 217   std::auto_ptr<MemoryBuffer> Buffer(
 218                        MemoryBuffer::getFileOrSTDIN(fName.c_str()));
 219   if (!Buffer.get()) {
 220     if (ErrMsg) *ErrMsg = "Could not open file '" + fName.toString() + "'";
 221     return true;
 222   }
 223
 224   ModuleProvider *MP = getBitcodeModuleProvider(Buffer.get(), Context, ErrMsg);
 225   if (!MP)
 226     return true;
 227
 228   // Get the module from the provider
 229   Module* M = MP->materializeModule();
 230   if (M == 0) {
 231     delete MP;
 232     return true;
 233   }
 234
 235   // Get the symbols
 236   getSymbols(M, symbols);
 237
 238   // Done with the module.
 239   delete MP;
 240   return true;
 241 }
 242
 243 ModuleProvider*
 244 llvm::GetBitcodeSymbols(const unsigned char *BufPtr, unsigned Length,
 245                         const std::string& ModuleID,
 246                         LLVMContext& Context,
 247                         std::vector<std::string>& symbols,
 248                         std::string* ErrMsg) {
 249   // Get the module provider
 250   MemoryBuffer *Buffer =MemoryBuffer::getNewMemBuffer(Length, ModuleID.c_str());
 251   memcpy((char*)Buffer->getBufferStart(), BufPtr, Length);
 252
 253   ModuleProvider *MP = getBitcodeModuleProvider(Buffer, Context, ErrMsg);
 254   if (!MP)
 255     return 0;
 256
 257   // Get the module from the provider
 258   Module* M = MP->materializeModule();
 259   if (M == 0) {
 260     delete MP;
 261     return 0;
 262   }
 263
 264   // Get the symbols
 265   getSymbols(M, symbols);
 266
 267   // Done with the module. Note that ModuleProvider will delete the
 268   // Module when it is deleted. Also note that its the caller's responsibility
 269   // to delete the ModuleProvider.
 270   return MP;
 271 }