llvm-6502/lib/Bytecode/Archive/ArchiveReader.cpp
Reid Spencer dd04df0ec3 For PR495:
Get rid of the difference between file paths and directory paths. The Path
class now simply stores a path that can refer to either a file or a
directory. This required various changes in the implementation and interface
of the class with the corresponding impact to its users. Doxygen comments were
also updated to reflect these changes. Interface changes are:

appendDirectory -> appendComponent
appendFile -> appendComponent
elideDirectory -> eraseComponent
elideFile -> eraseComponent
elideSuffix -> eraseSuffix
renameFile -> rename
setDirectory -> set
setFile -> set

Changes pass Dejagnu and llvm-test/SingleSource tests.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22349 91177308-0d34-0410-b5e6-96231b3b80d8
2005-07-07 23:21:43 +00:00

535 lines
17 KiB
C++

//===-- ArchiveReader.cpp - Read LLVM archive files -------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Reid Spencer and is distributed under the
// University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Builds up standard unix archive files (.a) containing LLVM bytecode.
//
//===----------------------------------------------------------------------===//
#include "ArchiveInternals.h"
#include "llvm/Bytecode/Reader.h"
using namespace llvm;
/// Read a variable-bit-rate encoded unsigned integer
inline unsigned readInteger(const char*&At, const char*End) {
unsigned Shift = 0;
unsigned Result = 0;
do {
if (At == End)
throw std::string("Ran out of data reading vbr_uint!");
Result |= (unsigned)((*At++) & 0x7F) << Shift;
Shift += 7;
} while (At[-1] & 0x80);
return Result;
}
// Completely parse the Archive's symbol table and populate symTab member var.
void
Archive::parseSymbolTable(const void* data, unsigned size) {
const char* At = (const char*) data;
const char* End = At + size;
while (At < End) {
unsigned offset = readInteger(At, End);
unsigned length = readInteger(At, End);
if (At + length > End)
throw std::string("malformed symbol table");
// we don't care if it can't be inserted (duplicate entry)
symTab.insert(std::make_pair(std::string(At, length), offset));
At += length;
}
symTabSize = size;
}
// This member parses an ArchiveMemberHeader that is presumed to be pointed to
// by At. The At pointer is updated to the byte just after the header, which
// can be variable in size.
ArchiveMember*
Archive::parseMemberHeader(const char*& At, const char* End) {
assert(At + sizeof(ArchiveMemberHeader) < End && "Not enough data");
// Cast archive member header
ArchiveMemberHeader* Hdr = (ArchiveMemberHeader*)At;
At += sizeof(ArchiveMemberHeader);
// Instantiate the ArchiveMember to be filled
ArchiveMember* member = new ArchiveMember(this);
// Extract the size and determine if the file is
// compressed or not (negative length).
int flags = 0;
int MemberSize = atoi(Hdr->size);
if (MemberSize < 0) {
flags |= ArchiveMember::CompressedFlag;
MemberSize = -MemberSize;
}
// Check the size of the member for sanity
if (At + MemberSize > End)
throw std::string("invalid member length in archive file");
// Check the member signature
if (!Hdr->checkSignature())
throw std::string("invalid file member signature");
// Convert and check the member name
// The empty name ( '/' and 15 blanks) is for a foreign (non-LLVM) symbol
// table. The special name "//" and 14 blanks is for a string table, used
// for long file names. This library doesn't generate either of those but
// it will accept them. If the name starts with #1/ and the remainder is
// digits, then those digits specify the length of the name that is
// stored immediately following the header. The special name
// __LLVM_SYM_TAB__ identifies the symbol table for LLVM bytecode.
// Anything else is a regular, short filename that is terminated with
// a '/' and blanks.
std::string pathname;
switch (Hdr->name[0]) {
case '#':
if (Hdr->name[1] == '1' && Hdr->name[2] == '/') {
if (isdigit(Hdr->name[3])) {
unsigned len = atoi(&Hdr->name[3]);
pathname.assign(At, len);
At += len;
MemberSize -= len;
flags |= ArchiveMember::HasLongFilenameFlag;
} else
throw std::string("invalid long filename");
} else if (Hdr->name[1] == '_' &&
(0 == memcmp(Hdr->name, ARFILE_LLVM_SYMTAB_NAME, 16))) {
// The member is using a long file name (>15 chars) format.
// This format is standard for 4.4BSD and Mac OSX operating
// systems. LLVM uses it similarly. In this format, the
// remainder of the name field (after #1/) specifies the
// length of the file name which occupy the first bytes of
// the member's data. The pathname already has the #1/ stripped.
pathname.assign(ARFILE_LLVM_SYMTAB_NAME);
flags |= ArchiveMember::LLVMSymbolTableFlag;
}
break;
case '/':
if (Hdr->name[1]== '/') {
if (0 == memcmp(Hdr->name, ARFILE_STRTAB_NAME, 16)) {
pathname.assign(ARFILE_STRTAB_NAME);
flags |= ArchiveMember::StringTableFlag;
} else {
throw std::string("invalid string table name");
}
} else if (Hdr->name[1] == ' ') {
if (0 == memcmp(Hdr->name, ARFILE_SVR4_SYMTAB_NAME, 16)) {
pathname.assign(ARFILE_SVR4_SYMTAB_NAME);
flags |= ArchiveMember::SVR4SymbolTableFlag;
} else {
throw std::string("invalid SVR4 symbol table name");
}
} else if (isdigit(Hdr->name[1])) {
unsigned index = atoi(&Hdr->name[1]);
if (index < strtab.length()) {
const char* namep = strtab.c_str() + index;
const char* endp = strtab.c_str() + strtab.length();
const char* p = namep;
const char* last_p = p;
while (p < endp) {
if (*p == '\n' && *last_p == '/') {
pathname.assign(namep, last_p - namep);
flags |= ArchiveMember::HasLongFilenameFlag;
break;
}
last_p = p;
p++;
}
if (p >= endp)
throw std::string("missing name termiantor in string table");
} else {
throw std::string("name index beyond string table");
}
}
break;
case '_':
if (Hdr->name[1] == '_' &&
(0 == memcmp(Hdr->name, ARFILE_BSD4_SYMTAB_NAME, 16))) {
pathname.assign(ARFILE_BSD4_SYMTAB_NAME);
flags |= ArchiveMember::BSD4SymbolTableFlag;
break;
}
/* FALL THROUGH */
default:
char* slash = (char*) memchr(Hdr->name, '/', 16);
if (slash == 0)
slash = Hdr->name + 16;
pathname.assign(Hdr->name, slash - Hdr->name);
break;
}
// Determine if this is a bytecode file
switch (sys::IdentifyFileType(At, 4)) {
case sys::BytecodeFileType:
flags |= ArchiveMember::BytecodeFlag;
break;
case sys::CompressedBytecodeFileType:
flags |= ArchiveMember::CompressedBytecodeFlag;
flags &= ~ArchiveMember::CompressedFlag;
break;
default:
flags &= ~(ArchiveMember::BytecodeFlag|
ArchiveMember::CompressedBytecodeFlag);
break;
}
// Fill in fields of the ArchiveMember
member->next = 0;
member->prev = 0;
member->parent = this;
member->path.set(pathname);
member->info.fileSize = MemberSize;
member->info.modTime.fromEpochTime(atoi(Hdr->date));
unsigned int mode;
sscanf(Hdr->mode, "%o", &mode);
member->info.mode = mode;
member->info.user = atoi(Hdr->uid);
member->info.group = atoi(Hdr->gid);
member->flags = flags;
member->data = At;
return member;
}
void
Archive::checkSignature() {
// Check the magic string at file's header
if (mapfile->size() < 8 || memcmp(base, ARFILE_MAGIC, 8))
throw std::string("invalid signature for an archive file");
}
// This function loads the entire archive and fully populates its ilist with
// the members of the archive file. This is typically used in preparation for
// editing the contents of the archive.
void
Archive::loadArchive() {
// Set up parsing
members.clear();
symTab.clear();
const char *At = base;
const char *End = base + mapfile->size();
checkSignature();
At += 8; // Skip the magic string.
bool seenSymbolTable = false;
bool foundFirstFile = false;
while (At < End) {
// parse the member header
const char* Save = At;
ArchiveMember* mbr = parseMemberHeader(At, End);
// check if this is the foreign symbol table
if (mbr->isSVR4SymbolTable() || mbr->isBSD4SymbolTable()) {
// We just save this but don't do anything special
// with it. It doesn't count as the "first file".
if (foreignST) {
// What? Multiple foreign symbol tables? Just chuck it
// and retain the last one found.
delete foreignST;
}
foreignST = mbr;
At += mbr->getSize();
if ((intptr_t(At) & 1) == 1)
At++;
} else if (mbr->isStringTable()) {
// Simply suck the entire string table into a string
// variable. This will be used to get the names of the
// members that use the "/ddd" format for their names
// (SVR4 style long names).
strtab.assign(At, mbr->getSize());
At += mbr->getSize();
if ((intptr_t(At) & 1) == 1)
At++;
delete mbr;
} else if (mbr->isLLVMSymbolTable()) {
// This is the LLVM symbol table for the archive. If we've seen it
// already, its an error. Otherwise, parse the symbol table and move on.
if (seenSymbolTable)
throw std::string("invalid archive: multiple symbol tables");
parseSymbolTable(mbr->getData(), mbr->getSize());
seenSymbolTable = true;
At += mbr->getSize();
if ((intptr_t(At) & 1) == 1)
At++;
delete mbr; // We don't need this member in the list of members.
} else {
// This is just a regular file. If its the first one, save its offset.
// Otherwise just push it on the list and move on to the next file.
if (!foundFirstFile) {
firstFileOffset = Save - base;
foundFirstFile = true;
}
members.push_back(mbr);
At += mbr->getSize();
if ((intptr_t(At) & 1) == 1)
At++;
}
}
}
// Open and completely load the archive file.
Archive*
Archive::OpenAndLoad(const sys::Path& file, std::string* ErrorMessage) {
try {
std::auto_ptr<Archive> result ( new Archive(file, true));
result->loadArchive();
return result.release();
} catch (const std::string& msg) {
if (ErrorMessage) {
*ErrorMessage = msg;
}
return 0;
}
}
// Get all the bytecode modules from the archive
bool
Archive::getAllModules(std::vector<Module*>& Modules, std::string* ErrMessage) {
for (iterator I=begin(), E=end(); I != E; ++I) {
if (I->isBytecode() || I->isCompressedBytecode()) {
std::string FullMemberName = archPath.toString() +
"(" + I->getPath().toString() + ")";
Module* M = ParseBytecodeBuffer((const unsigned char*)I->getData(),
I->getSize(), FullMemberName, ErrMessage);
if (!M)
return true;
Modules.push_back(M);
}
}
return false;
}
// Load just the symbol table from the archive file
void
Archive::loadSymbolTable() {
// Set up parsing
members.clear();
symTab.clear();
const char *At = base;
const char *End = base + mapfile->size();
// Make sure we're dealing with an archive
checkSignature();
At += 8; // Skip signature
// Parse the first file member header
const char* FirstFile = At;
ArchiveMember* mbr = parseMemberHeader(At, End);
if (mbr->isSVR4SymbolTable() || mbr->isBSD4SymbolTable()) {
// Skip the foreign symbol table, we don't do anything with it
At += mbr->getSize();
if ((intptr_t(At) & 1) == 1)
At++;
delete mbr;
// Read the next one
FirstFile = At;
mbr = parseMemberHeader(At, End);
}
if (mbr->isStringTable()) {
// Process the string table entry
strtab.assign((const char*)mbr->getData(), mbr->getSize());
At += mbr->getSize();
if ((intptr_t(At) & 1) == 1)
At++;
delete mbr;
// Get the next one
FirstFile = At;
mbr = parseMemberHeader(At, End);
}
// See if its the symbol table
if (mbr->isLLVMSymbolTable()) {
parseSymbolTable(mbr->getData(), mbr->getSize());
At += mbr->getSize();
if ((intptr_t(At) & 1) == 1)
At++;
FirstFile = At;
} else {
// There's no symbol table in the file. We have to rebuild it from scratch
// because the intent of this method is to get the symbol table loaded so
// it can be searched efficiently.
// Add the member to the members list
members.push_back(mbr);
}
firstFileOffset = FirstFile - base;
}
// Open the archive and load just the symbol tables
Archive*
Archive::OpenAndLoadSymbols(const sys::Path& file, std::string* ErrorMessage) {
try {
std::auto_ptr<Archive> result ( new Archive(file, true) );
result->loadSymbolTable();
return result.release();
} catch (const std::string& msg) {
if (ErrorMessage) {
*ErrorMessage = msg;
}
return 0;
}
}
// Look up one symbol in the symbol table and return a ModuleProvider for the
// module that defines that symbol.
ModuleProvider*
Archive::findModuleDefiningSymbol(const std::string& symbol) {
SymTabType::iterator SI = symTab.find(symbol);
if (SI == symTab.end())
return 0;
// The symbol table was previously constructed assuming that the members were
// written without the symbol table header. Because VBR encoding is used, the
// values could not be adjusted to account for the offset of the symbol table
// because that could affect the size of the symbol table due to VBR encoding.
// We now have to account for this by adjusting the offset by the size of the
// symbol table and its header.
unsigned fileOffset =
SI->second + // offset in symbol-table-less file
firstFileOffset; // add offset to first "real" file in archive
// See if the module is already loaded
ModuleMap::iterator MI = modules.find(fileOffset);
if (MI != modules.end())
return MI->second.first;
// Module hasn't been loaded yet, we need to load it
const char* modptr = base + fileOffset;
ArchiveMember* mbr = parseMemberHeader(modptr, base + mapfile->size());
// Now, load the bytecode module to get the ModuleProvider
std::string FullMemberName = archPath.toString() + "(" +
mbr->getPath().toString() + ")";
ModuleProvider* mp = getBytecodeBufferModuleProvider(
(const unsigned char*) mbr->getData(), mbr->getSize(),
FullMemberName, 0);
modules.insert(std::make_pair(fileOffset, std::make_pair(mp, mbr)));
return mp;
}
// Look up multiple symbols in the symbol table and return a set of
// ModuleProviders that define those symbols.
void
Archive::findModulesDefiningSymbols(std::set<std::string>& symbols,
std::set<ModuleProvider*>& result)
{
assert(mapfile && base && "Can't findModulesDefiningSymbols on new archive");
if (symTab.empty()) {
// We don't have a symbol table, so we must build it now but lets also
// make sure that we populate the modules table as we do this to ensure
// that we don't load them twice when findModuleDefiningSymbol is called
// below.
// Get a pointer to the first file
const char* At = ((const char*)base) + firstFileOffset;
const char* End = ((const char*)base) + mapfile->size();
while ( At < End) {
// Compute the offset to be put in the symbol table
unsigned offset = At - base - firstFileOffset;
// Parse the file's header
ArchiveMember* mbr = parseMemberHeader(At, End);
// If it contains symbols
if (mbr->isBytecode() || mbr->isCompressedBytecode()) {
// Get the symbols
std::vector<std::string> symbols;
std::string FullMemberName = archPath.toString() + "(" +
mbr->getPath().toString() + ")";
ModuleProvider* MP = GetBytecodeSymbols((const unsigned char*)At,
mbr->getSize(), FullMemberName, symbols);
if (MP) {
// Insert the module's symbols into the symbol table
for (std::vector<std::string>::iterator I = symbols.begin(),
E=symbols.end(); I != E; ++I ) {
symTab.insert(std::make_pair(*I, offset));
}
// Insert the ModuleProvider and the ArchiveMember into the table of
// modules.
modules.insert(std::make_pair(offset, std::make_pair(MP, mbr)));
} else {
throw std::string("Can't parse bytecode member: ") +
mbr->getPath().toString();
}
}
// Go to the next file location
At += mbr->getSize();
if ((intptr_t(At) & 1) == 1)
At++;
}
}
// At this point we have a valid symbol table (one way or another) so we
// just use it to quickly find the symbols requested.
for (std::set<std::string>::iterator I=symbols.begin(),
E=symbols.end(); I != E;) {
// See if this symbol exists
ModuleProvider* mp = findModuleDefiningSymbol(*I);
if (mp) {
// The symbol exists, insert the ModuleProvider into our result,
// duplicates wil be ignored
result.insert(mp);
// Remove the symbol now that its been resolved, being careful to
// post-increment the iterator.
symbols.erase(I++);
} else {
++I;
}
}
}
bool
Archive::isBytecodeArchive()
{
//Make sure the symTab has been loaded...
//in most cases this should have been done
//when the archive was constructed, but still,
//this is just in case.
if ( !symTab.size() )
loadSymbolTable();
//Now that we know it's been loaded, return true
//if it has a size
if ( symTab.size() ) return true;
//We still can't be sure it isn't a bytecode archive
loadArchive();
std::vector<Module *> Modules;
std::string ErrorMessage;
//If getAllModules gives an error then this isn't a proper
//bytecode archive
if ( getAllModules( Modules, &ErrorMessage ) ) return false;
//Finally, if we find any bytecode modules then this is a proper
//bytecode archive
return Modules.size();
}