// 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, std::string* error)
{
if (At + sizeof(ArchiveMemberHeader) >= End) {
if (error)
*error = "Unexpected end of file";
return 0;
}
// Cast archive member header
ArchiveMemberHeader* Hdr = (ArchiveMemberHeader*)At;
At += sizeof(ArchiveMemberHeader);
// 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) {
if (error)
*error = "invalid member length in archive file";
return 0;
}
// Check the member signature
if (!Hdr->checkSignature()) {
if (error)
*error = "invalid file member signature";
return 0;
}
// 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 bitcode.
// 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]);
const char *nulp = (const char *)memchr(At, '\0', len);
pathname.assign(At, nulp != 0 ? (uintptr_t)(nulp - At) : len);
At += len;
MemberSize -= len;
flags |= ArchiveMember::HasLongFilenameFlag;
} else {
if (error)
*error = "invalid long filename";
return 0;
}
} 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 {
if (error)
*error = "invalid string table name";
return 0;
}
} 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 {
if (error)
*error = "invalid SVR4 symbol table name";
return 0;
}
} 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) {
if (error)
*error = "missing name termiantor in string table";
return 0;
}
} else {
if (error)
*error = "name index beyond string table";
return 0;
}
}
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 bitcode file
switch (sys::IdentifyFileType(At, 4)) {
case sys::Bitcode_FileType:
flags |= ArchiveMember::BitcodeFlag;
break;
default:
flags &= ~ArchiveMember::BitcodeFlag;
break;
}
// Instantiate the ArchiveMember to be filled
ArchiveMember* member = new ArchiveMember(this);
// Fill in fields of the ArchiveMember
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;
}
