llvm-6502/lib/Bytecode/Reader/ArchiveReader.cpp
Brian Gaeke 60d6e54c72 Use the true, decoded name of the archive member in getObjectType.
In ReadArchiveBuffer, make sure that MemberName is set in the case where
getObjectType would want to return SVR4LongFilename.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12567 91177308-0d34-0410-b5e6-96231b3b80d8
2004-03-31 19:51:00 +00:00

197 lines
7.2 KiB
C++

//===- ArchiveReader.cpp - Code to read LLVM bytecode from .a files -------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the ReadArchiveFile interface, which allows a linker to
// read all of the LLVM bytecode files contained in a .a file. This file
// understands the standard system .a file format. This can only handle the .a
// variant prevalent on Linux systems so far, but may be extended. See
// information in this source file for more information:
// http://sources.redhat.com/cgi-bin/cvsweb.cgi/src/bfd/archive.c?cvsroot=src
//
//===----------------------------------------------------------------------===//
#include "llvm/Bytecode/Reader.h"
#include "llvm/Module.h"
#include "Support/FileUtilities.h"
#include "Config/sys/mman.h"
#include "Config/fcntl.h"
#include <cstdlib>
using namespace llvm;
namespace {
struct ar_hdr {
char name[16];
char date[12];
char uid[6];
char gid[6];
char mode[8];
char size[10];
char fmag[2]; // Always equal to '`\n'
};
enum ObjectType {
UserObject, // A user .o/.bc file
Unknown, // Unknown file, just ignore it
SVR4LongFilename, // a "//" section used for long file names
ArchiveSymbolTable, // Symbol table produced by ranlib.
};
}
/// getObjectType - Determine the type of object that this header represents.
/// This is capable of parsing the variety of special sections used for various
/// purposes.
///
static enum ObjectType getObjectType(ar_hdr *H, std::string MemberName,
unsigned char *MemberData, unsigned Size) {
// Check for sections with special names...
if (MemberName == "__.SYMDEF " || MemberName == "__.SYMDEF SORTED")
return ArchiveSymbolTable;
else if (MemberName == "// ")
return SVR4LongFilename;
// Check to see if it looks like an llvm object file...
if (Size >= 4 && !memcmp(MemberData, "llvm", 4))
return UserObject;
return Unknown;
}
static inline bool Error(std::string *ErrorStr, const char *Message) {
if (ErrorStr) *ErrorStr = Message;
return true;
}
static bool ParseSymbolTableSection(unsigned char *Buffer, unsigned Size,
std::string *S) {
// Currently not supported (succeeds without doing anything)
return false;
}
static bool ReadArchiveBuffer(const std::string &ArchiveName,
unsigned char *Buffer, unsigned Length,
std::vector<Module*> &Objects,
std::string *ErrorStr) {
if (Length < 8 || memcmp(Buffer, "!<arch>\n", 8))
return Error(ErrorStr, "signature incorrect for an archive file!");
Buffer += 8; Length -= 8; // Skip the magic string.
std::vector<char> LongFilenames;
while (Length >= sizeof(ar_hdr)) {
ar_hdr *Hdr = (ar_hdr*)Buffer;
unsigned SizeFromHeader = atoi(Hdr->size);
if (SizeFromHeader + sizeof(ar_hdr) > Length)
return Error(ErrorStr, "invalid record length in archive file!");
unsigned char *MemberData = Buffer + sizeof(ar_hdr);
unsigned MemberSize = SizeFromHeader;
// Get name of archive member.
char *startp = Hdr->name;
char *endp = (char *) memchr (startp, '/', sizeof(ar_hdr));
if (memcmp (Hdr->name, "#1/", 3) == 0) {
// 4.4BSD/MacOSX long filenames are abbreviated as "#1/L", where L is an
// ASCII-coded decimal number representing the length of the name buffer,
// which is prepended to the archive member's contents.
unsigned NameLength = atoi (&Hdr->name[3]);
startp = (char *) MemberData;
endp = startp + NameLength;
MemberData += NameLength;
MemberSize -= NameLength;
} else if (startp == endp && isdigit (Hdr->name[1])) {
// SVR4 long filenames are abbreviated as "/I", where I is
// an ASCII-coded decimal index into the LongFilenames vector.
unsigned NameIndex = atoi (&Hdr->name[1]);
assert (LongFilenames.size () > NameIndex
&& "SVR4-style long filename for archive member not found");
startp = &LongFilenames[NameIndex];
endp = strchr (startp, '/');
} else if (startp == endp && Hdr->name[1] == '/') {
// This is for the SVR4 long filename table (there might be other
// names starting with // but I don't know about them). Make sure that
// getObjectType sees it.
endp = &Hdr->name[sizeof (Hdr->name)];
}
if (!endp) {
// 4.4BSD/MacOSX *short* filenames are not guaranteed to have a
// terminator. Start at the end of the field and backtrack over spaces.
endp = startp + sizeof(Hdr->name);
while (endp[-1] == ' ')
--endp;
}
std::string MemberName (startp, endp);
std::string FullMemberName = ArchiveName + "(" + MemberName + ")";
switch (getObjectType(Hdr, MemberName, MemberData, MemberSize)) {
case SVR4LongFilename:
// If this is a long filename section, read all of the file names into the
// LongFilenames vector.
LongFilenames.assign (MemberData, MemberData + MemberSize);
break;
case UserObject: {
Module *M = ParseBytecodeBuffer(MemberData, MemberSize,
FullMemberName, ErrorStr);
if (!M) return true;
Objects.push_back(M);
break;
}
case ArchiveSymbolTable:
if (ParseSymbolTableSection(MemberData, MemberSize, ErrorStr))
return true;
break;
default:
std::cerr << "ReadArchiveBuffer: WARNING: Skipping unknown file: "
<< FullMemberName << "\n";
break; // Just ignore unknown files.
}
// Round SizeFromHeader up to an even number...
SizeFromHeader = (SizeFromHeader+1)/2*2;
Buffer += sizeof(ar_hdr)+SizeFromHeader; // Move to the next entry
Length -= sizeof(ar_hdr)+SizeFromHeader;
}
return Length != 0;
}
// ReadArchiveFile - Read bytecode files from the specified .a file, returning
// true on error, or false on success. This does not support reading files from
// standard input.
//
bool llvm::ReadArchiveFile(const std::string &Filename,
std::vector<Module*> &Objects,std::string *ErrorStr){
int Length = getFileSize(Filename);
if (Length == -1)
return Error(ErrorStr, "Error getting file length!");
int FD = open(Filename.c_str(), O_RDONLY);
if (FD == -1)
return Error(ErrorStr, "Error opening file!");
// mmap in the file all at once...
unsigned char *Buffer = (unsigned char*)mmap(0, Length, PROT_READ,
MAP_PRIVATE, FD, 0);
if (Buffer == (unsigned char*)MAP_FAILED)
return Error(ErrorStr, "Error mmapping file!");
// Parse the archive files we mmap'ped in
bool Result = ReadArchiveBuffer(Filename, Buffer, Length, Objects, ErrorStr);
// Unmmap the archive...
munmap((char*)Buffer, Length);
if (Result) // Free any loaded objects
while (!Objects.empty()) {
delete Objects.back();
Objects.pop_back();
}
return Result;
}