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/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>
  24 using 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.
  28 unsigned
  29 ArchiveMember::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.
  46 ArchiveMember::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.
  61 ArchiveMember::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.
  69 bool 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.
 145 Archive::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
 150 bool
 151 Archive::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
 163 void 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
 190 Archive::~Archive() {
 191   cleanUpMemory();
 192 }
 193
 194
 195
 196 static 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
 218 bool 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
 241 Module*
 242 llvm::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 }