//===-- llvm-ar.cpp - LLVM archive librarian utility ----------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Builds up (relatively) standard unix archive files (.a) containing LLVM
// bitcode or other files.
//
//===----------------------------------------------------------------------===//
#include "llvm/LLVMContext.h"
#include "llvm/Module.h"
#include "llvm/Bitcode/Archive.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/PrettyStackTrace.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/Signals.h"
#include <algorithm>
#include <memory>
#include <fstream>
using namespace llvm;
// Option for compatibility with AIX, not used but must allow it to be present.
static cl::opt<bool>
X32Option ("X32_64", cl::Hidden,
cl::desc("Ignored option for compatibility with AIX"));
// llvm-ar operation code and modifier flags. This must come first.
static cl::opt<std::string>
Options(cl::Positional, cl::Required, cl::desc("{operation}[modifiers]..."));
// llvm-ar remaining positional arguments.
static cl::list<std::string>
RestOfArgs(cl::Positional, cl::OneOrMore,
cl::desc("[relpos] [count] <archive-file> [members]..."));
// MoreHelp - Provide additional help output explaining the operations and
// modifiers of llvm-ar. This object instructs the CommandLine library
// to print the text of the constructor when the --help option is given.
static cl::extrahelp MoreHelp(
"\nOPERATIONS:\n"
" d[NsS] - delete file(s) from the archive\n"
" m[abiSs] - move file(s) in the archive\n"
" p[kN] - print file(s) found in the archive\n"
" q[ufsS] - quick append file(s) to the archive\n"
" r[abfiuzRsS] - replace or insert file(s) into the archive\n"
" t - display contents of archive\n"
" x[No] - extract file(s) from the archive\n"
"\nMODIFIERS (operation specific):\n"
" [a] - put file(s) after [relpos]\n"
" [b] - put file(s) before [relpos] (same as [i])\n"
" [f] - truncate inserted file names\n"
" [i] - put file(s) before [relpos] (same as [b])\n"
" [k] - always print bitcode files (default is to skip them)\n"
" [N] - use instance [count] of name\n"
" [o] - preserve original dates\n"
" [P] - use full path names when matching\n"
" [R] - recurse through directories when inserting\n"
" [s] - create an archive index (cf. ranlib)\n"
" [S] - do not build a symbol table\n"
" [u] - update only files newer than archive contents\n"
" [z] - compress files before inserting/extracting\n"
"\nMODIFIERS (generic):\n"
" [c] - do not warn if the library had to be created\n"
" [v] - be verbose about actions taken\n"
" [V] - be *really* verbose about actions taken\n"
);
// This enumeration delineates the kinds of operations on an archive
// that are permitted.
enum ArchiveOperation {
NoOperation, ///< An operation hasn't been specified
Print, ///< Print the contents of the archive
Delete, ///< Delete the specified members
Move, ///< Move members to end or as given by {a,b,i} modifiers
QuickAppend, ///< Quickly append to end of archive
ReplaceOrInsert, ///< Replace or Insert members
DisplayTable, ///< Display the table of contents
Extract ///< Extract files back to file system
};
// Modifiers to follow operation to vary behavior
bool AddAfter = false; ///< 'a' modifier
bool AddBefore = false; ///< 'b' modifier
bool Create = false; ///< 'c' modifier
bool TruncateNames = false; ///< 'f' modifier
bool InsertBefore = false; ///< 'i' modifier
bool DontSkipBitcode = false; ///< 'k' modifier
bool UseCount = false; ///< 'N' modifier
bool OriginalDates = false; ///< 'o' modifier
bool FullPath = false; ///< 'P' modifier
bool RecurseDirectories = false; ///< 'R' modifier
bool SymTable = true; ///< 's' & 'S' modifiers
bool OnlyUpdate = false; ///< 'u' modifier
bool Verbose = false; ///< 'v' modifier
bool ReallyVerbose = false; ///< 'V' modifier
bool Compression = false; ///< 'z' modifier
// Relative Positional Argument (for insert/move). This variable holds
// the name of the archive member to which the 'a', 'b' or 'i' modifier
// refers. Only one of 'a', 'b' or 'i' can be specified so we only need
// one variable.
std::string RelPos;
// Select which of multiple entries in the archive with the same name should be
// used (specified with -N) for the delete and extract operations.
int Count = 1;
// This variable holds the name of the archive file as given on the
// command line.
std::string ArchiveName;
// This variable holds the list of member files to proecess, as given
// on the command line.
std::vector<std::string> Members;
// This variable holds the (possibly expanded) list of path objects that
// correspond to files we will
std::set<sys::Path> Paths;
// The Archive object to which all the editing operations will be sent.
Archive* TheArchive = 0;
// getRelPos - Extract the member filename from the command line for
// the [relpos] argument associated with a, b, and i modifiers
void getRelPos() {
if(RestOfArgs.size() > 0) {
RelPos = RestOfArgs[0];
RestOfArgs.erase(RestOfArgs.begin());
}
else
throw "Expected [relpos] for a, b, or i modifier";
}
// getCount - Extract the [count] argument associated with the N modifier
// from the command line and check its value.
void getCount() {
if(RestOfArgs.size() > 0) {
Count = atoi(RestOfArgs[0].c_str());
RestOfArgs.erase(RestOfArgs.begin());
}
else
throw "Expected [count] value with N modifier";
// Non-positive counts are not allowed
if (Count < 1)
throw "Invalid [count] value (not a positive integer)";
}
// getArchive - Get the archive file name from the command line
void getArchive() {
if(RestOfArgs.size() > 0) {
ArchiveName = RestOfArgs[0];
RestOfArgs.erase(RestOfArgs.begin());
}
else
throw "An archive name must be specified.";
}
// getMembers - Copy over remaining items in RestOfArgs to our Members vector
// This is just for clarity.
void getMembers() {
if(RestOfArgs.size() > 0)
Members = std::vector<std::string>(RestOfArgs);
}
// parseCommandLine - Parse the command line options as presented and return the
// operation specified. Process all modifiers and check to make sure that
// constraints on modifier/operation pairs have not been violated.
ArchiveOperation parseCommandLine() {
// Keep track of number of operations. We can only specify one
// per execution.
unsigned NumOperations = 0;
// Keep track of the number of positional modifiers (a,b,i). Only
// one can be specified.
unsigned NumPositional = 0;
// Keep track of which operation was requested
ArchiveOperation Operation = NoOperation;
for(unsigned i=0; i<Options.size(); ++i) {
switch(Options[i]) {
case 'd': ++NumOperations; Operation = Delete; break;
case 'm': ++NumOperations; Operation = Move ; break;
case 'p': ++NumOperations; Operation = Print; break;
case 'q': ++NumOperations; Operation = QuickAppend; break;
case 'r': ++NumOperations; Operation = ReplaceOrInsert; break;
case 't': ++NumOperations; Operation = DisplayTable; break;
case 'x': ++NumOperations; Operation = Extract; break;
case 'c': Create = true; break;
case 'f': TruncateNames = true; break;
case 'k': DontSkipBitcode = true; break;
case 'l': /* accepted but unused */ break;
case 'o': OriginalDates = true; break;
case 'P': FullPath = true; break;
case 'R': RecurseDirectories = true; break;
case 's': SymTable = true; break;
case 'S': SymTable = false; break;
case 'u': OnlyUpdate = true; break;
case 'v': Verbose = true; break;
case 'V': Verbose = ReallyVerbose = true; break;
case 'z': Compression = true; break;
case 'a':
getRelPos();
AddAfter = true;
NumPositional++;
break;
case 'b':
getRelPos();
AddBefore = true;
NumPositional++;
break;
case 'i':
getRelPos();
InsertBefore = true;
NumPositional++;
break;
case 'N':
getCount();
UseCount = true;
break;
default:
cl::PrintHelpMessage();
}
}
// At this point, the next thing on the command line must be
// the archive name.
getArchive();
// Everything on the command line at this point is a member.
getMembers();
// Perform various checks on the operation/modifier specification
// to make sure we are dealing with a legal request.
if (NumOperations == 0)
throw "You must specify at least one of the operations";
if (NumOperations > 1)
throw "Only one operation may be specified";
if (NumPositional > 1)
throw "You may only specify one of a, b, and i modifiers";
if (AddAfter || AddBefore || InsertBefore)
if (Operation != Move && Operation != ReplaceOrInsert)
throw "The 'a', 'b' and 'i' modifiers can only be specified with "
"the 'm' or 'r' operations";
if (RecurseDirectories && Operation != ReplaceOrInsert)
throw "The 'R' modifiers is only applicabe to the 'r' operation";
if (OriginalDates && Operation != Extract)
throw "The 'o' modifier is only applicable to the 'x' operation";
if (TruncateNames && Operation!=QuickAppend && Operation!=ReplaceOrInsert)
throw "The 'f' modifier is only applicable to the 'q' and 'r' operations";
if (OnlyUpdate && Operation != ReplaceOrInsert)
throw "The 'u' modifier is only applicable to the 'r' operation";
if (Compression && Operation!=ReplaceOrInsert && Operation!=Extract)
throw "The 'z' modifier is only applicable to the 'r' and 'x' operations";
if (Count > 1 && Members.size() > 1)
throw "Only one member name may be specified with the 'N' modifier";
// Return the parsed operation to the caller
return Operation;
}
// recurseDirectories - Implements the "R" modifier. This function scans through
// the Paths vector (built by buildPaths, below) and replaces any directories it
// finds with all the files in that directory (recursively). It uses the
// sys::Path::getDirectoryContent method to perform the actual directory scans.
bool
recurseDirectories(const sys::Path& path,
std::set<sys::Path>& result, std::string* ErrMsg) {
result.clear();
if (RecurseDirectories) {
std::set<sys::Path> content;
if (path.getDirectoryContents(content, ErrMsg))
return true;
for (std::set<sys::Path>::iterator I = content.begin(), E = content.end();
I != E; ++I) {
// Make sure it exists and is a directory
sys::PathWithStatus PwS(*I);
const sys::FileStatus *Status = PwS.getFileStatus(false, ErrMsg);
if (!Status)
return true;
if (Status->isDir) {
std::set<sys::Path> moreResults;
if (recurseDirectories(*I, moreResults, ErrMsg))
return true;
result.insert(moreResults.begin(), moreResults.end());
} else {
result.insert(*I);
}
}
}
return false;
}
// buildPaths - Convert the strings in the Members vector to sys::Path objects
// and make sure they are valid and exist exist. This check is only needed for
// the operations that add/replace files to the archive ('q' and 'r')
bool buildPaths(bool checkExistence, std::string* ErrMsg) {
for (unsigned i = 0; i < Members.size(); i++) {
sys::Path aPath;
if (!aPath.set(Members[i]))
throw std::string("File member name invalid: ") + Members[i];
if (checkExistence) {
bool Exists;
if (sys::fs::exists(aPath.str(), Exists) || !Exists)
throw std::string("File does not exist: ") + Members[i];
std::string Err;
sys::PathWithStatus PwS(aPath);
const sys::FileStatus *si = PwS.getFileStatus(false, &Err);
if (!si)
throw Err;
if (si->isDir) {
std::set<sys::Path> dirpaths;
if (recurseDirectories(aPath, dirpaths, ErrMsg))
return true;
Paths.insert(dirpaths.begin(),dirpaths.end());
} else {
Paths.insert(aPath);
}
} else {
Paths.insert(aPath);
}
}
return false;
}
// printSymbolTable - print out the archive's symbol table.
void printSymbolTable() {
outs() << "\nArchive Symbol Table:\n";
const Archive::SymTabType& symtab = TheArchive->getSymbolTable();
for (Archive::SymTabType::const_iterator I=symtab.begin(), E=symtab.end();
I != E; ++I ) {
unsigned offset = TheArchive->getFirstFileOffset() + I->second;
outs() << " " << format("%9u", offset) << "\t" << I->first <<"\n";
}
}
// doPrint - Implements the 'p' operation. This function traverses the archive
// looking for members that match the path list. It is careful to uncompress
// things that should be and to skip bitcode files unless the 'k' modifier was
// given.
bool doPrint(std::string* ErrMsg) {
if (buildPaths(false, ErrMsg))
return true;
unsigned countDown = Count;
for (Archive::iterator I = TheArchive->begin(), E = TheArchive->end();
I != E; ++I ) {
if (Paths.empty() ||
(std::find(Paths.begin(), Paths.end(), I->getPath()) != Paths.end())) {
if (countDown == 1) {
const char* data = reinterpret_cast<const char*>(I->getData());
// Skip things that don't make sense to print
if (I->isLLVMSymbolTable() || I->isSVR4SymbolTable() ||
I->isBSD4SymbolTable() || (!DontSkipBitcode && I->isBitcode()))
continue;
if (Verbose)
outs() << "Printing " << I->getPath().str() << "\n";
unsigned len = I->getSize();
outs().write(data, len);
} else {
countDown--;
}
}
}
return false;
}
// putMode - utility function for printing out the file mode when the 't'
// operation is in verbose mode.
void
printMode(unsigned mode) {
if (mode & 004)
outs() << "r";
else
outs() << "-";
if (mode & 002)
outs() << "w";
else
outs() << "-";
if (mode & 001)
outs() << "x";
else
outs() << "-";
}
// doDisplayTable - Implement the 't' operation. This function prints out just
// the file names of each of the members. However, if verbose mode is requested
// ('v' modifier) then the file type, permission mode, user, group, size, and
// modification time are also printed.
bool
doDisplayTable(std::string* ErrMsg) {
if (buildPaths(false, ErrMsg))
return true;
for (Archive::iterator I = TheArchive->begin(), E = TheArchive->end();
I != E; ++I ) {
if (Paths.empty() ||
(std::find(Paths.begin(), Paths.end(), I->getPath()) != Paths.end())) {
if (Verbose) {
// FIXME: Output should be this format:
// Zrw-r--r-- 500/ 500 525 Nov 8 17:42 2004 Makefile
if (I->isBitcode())
outs() << "b";
else if (I->isCompressed())
outs() << "Z";
else
outs() << " ";
unsigned mode = I->getMode();
printMode((mode >> 6) & 007);
printMode((mode >> 3) & 007);
printMode(mode & 007);
outs() << " " << format("%4u", I->getUser());
outs() << "/" << format("%4u", I->getGroup());
outs() << " " << format("%8u", I->getSize());
outs() << " " << format("%20s", I->getModTime().str().substr(4).c_str());
outs() << " " << I->getPath().str() << "\n";
} else {
outs() << I->getPath().str() << "\n";
}
}
}
if (ReallyVerbose)
printSymbolTable();
return false;
}
// doExtract - Implement the 'x' operation. This function extracts files back to
// the file system, making sure to uncompress any that were compressed
bool
doExtract(std::string* ErrMsg) {
if (buildPaths(false, ErrMsg))
return true;
for (Archive::iterator I = TheArchive->begin(), E = TheArchive->end();
I != E; ++I ) {
if (Paths.empty() ||
(std::find(Paths.begin(), Paths.end(), I->getPath()) != Paths.end())) {
// Make sure the intervening directories are created
if (I->hasPath()) {
sys::Path dirs(I->getPath());
dirs.eraseComponent();
if (dirs.createDirectoryOnDisk(/*create_parents=*/true, ErrMsg))
return true;
}
// Open up a file stream for writing
std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
std::ios::binary;
std::ofstream file(I->getPath().c_str(), io_mode);
// Get the data and its length
const char* data = reinterpret_cast<const char*>(I->getData());
unsigned len = I->getSize();
// Write the data.
file.write(data,len);
file.close();
// If we're supposed to retain the original modification times, etc. do so
// now.
if (OriginalDates)
I->getPath().setStatusInfoOnDisk(I->getFileStatus());
}
}
return false;
}
// doDelete - Implement the delete operation. This function deletes zero or more
// members from the archive. Note that if the count is specified, there should
// be no more than one path in the Paths list or else this algorithm breaks.
// That check is enforced in parseCommandLine (above).
bool
doDelete(std::string* ErrMsg) {
if (buildPaths(false, ErrMsg))
return true;
if (Paths.empty())
return false;
unsigned countDown = Count;
for (Archive::iterator I = TheArchive->begin(), E = TheArchive->end();
I != E; ) {
if (std::find(Paths.begin(), Paths.end(), I->getPath()) != Paths.end()) {
if (countDown == 1) {
Archive::iterator J = I;
++I;
TheArchive->erase(J);
} else
countDown--;
} else {
++I;
}
}
// We're done editting, reconstruct the archive.
if (TheArchive->writeToDisk(SymTable,TruncateNames,Compression,ErrMsg))
return true;
if (ReallyVerbose)
printSymbolTable();
return false;
}
// doMore - Implement the move operation. This function re-arranges just the
// order of the archive members so that when the archive is written the move
// of the members is accomplished. Note the use of the RelPos variable to
// determine where the items should be moved to.
bool
doMove(std::string* ErrMsg) {
if (buildPaths(false, ErrMsg))
return true;
// By default and convention the place to move members to is the end of the
// archive.
Archive::iterator moveto_spot = TheArchive->end();
// However, if the relative positioning modifiers were used, we need to scan
// the archive to find the member in question. If we don't find it, its no
// crime, we just move to the end.
if (AddBefore || InsertBefore || AddAfter) {
for (Archive::iterator I = TheArchive->begin(), E= TheArchive->end();
I != E; ++I ) {
if (RelPos == I->getPath().str()) {
if (AddAfter) {
moveto_spot = I;
moveto_spot++;
} else {
moveto_spot = I;
}
break;
}
}
}
// Keep a list of the paths remaining to be moved
std::set<sys::Path> remaining(Paths);
// Scan the archive again, this time looking for the members to move to the
// moveto_spot.
for (Archive::iterator I = TheArchive->begin(), E= TheArchive->end();
I != E && !remaining.empty(); ++I ) {
std::set<sys::Path>::iterator found =
std::find(remaining.begin(),remaining.end(),I->getPath());
if (found != remaining.end()) {
if (I != moveto_spot)
TheArchive->splice(moveto_spot,*TheArchive,I);
remaining.erase(found);
}
}
// We're done editting, reconstruct the archive.
if (TheArchive->writeToDisk(SymTable,TruncateNames,Compression,ErrMsg))
return true;
if (ReallyVerbose)
printSymbolTable();
return false;
}
// doQuickAppend - Implements the 'q' operation. This function just
// indiscriminantly adds the members to the archive and rebuilds it.
bool
doQuickAppend(std::string* ErrMsg) {
// Get the list of paths to append.
if (buildPaths(true, ErrMsg))
return true;
if (Paths.empty())
return false;
// Append them quickly.
for (std::set<sys::Path>::iterator PI = Paths.begin(), PE = Paths.end();
PI != PE; ++PI) {
if (TheArchive->addFileBefore(*PI,TheArchive->end(),ErrMsg))
return true;
}
// We're done editting, reconstruct the archive.
if (TheArchive->writeToDisk(SymTable,TruncateNames,Compression,ErrMsg))
return true;
if (ReallyVerbose)
printSymbolTable();
return false;
}
// doReplaceOrInsert - Implements the 'r' operation. This function will replace
// any existing files or insert new ones into the archive.
bool
doReplaceOrInsert(std::string* ErrMsg) {
// Build the list of files to be added/replaced.
if (buildPaths(true, ErrMsg))
return true;
if (Paths.empty())
return false;
// Keep track of the paths that remain to be inserted.
std::set<sys::Path> remaining(Paths);
// Default the insertion spot to the end of the archive
Archive::iterator insert_spot = TheArchive->end();
// Iterate over the archive contents
for (Archive::iterator I = TheArchive->begin(), E = TheArchive->end();
I != E && !remaining.empty(); ++I ) {
// Determine if this archive member matches one of the paths we're trying
// to replace.
std::set<sys::Path>::iterator found = remaining.end();
for (std::set<sys::Path>::iterator RI = remaining.begin(),
RE = remaining.end(); RI != RE; ++RI ) {
std::string compare(RI->str());
if (TruncateNames && compare.length() > 15) {
const char* nm = compare.c_str();
unsigned len = compare.length();
size_t slashpos = compare.rfind('/');
if (slashpos != std::string::npos) {
nm += slashpos + 1;
len -= slashpos +1;
}
if (len > 15)
len = 15;
compare.assign(nm,len);
}
if (compare == I->getPath().str()) {
found = RI;
break;
}
}
if (found != remaining.end()) {
std::string Err;
sys::PathWithStatus PwS(*found);
const sys::FileStatus *si = PwS.getFileStatus(false, &Err);
if (!si)
return true;
if (!si->isDir) {
if (OnlyUpdate) {
// Replace the item only if it is newer.
if (si->modTime > I->getModTime())
if (I->replaceWith(*found, ErrMsg))
return true;
} else {
// Replace the item regardless of time stamp
if (I->replaceWith(*found, ErrMsg))
return true;
}
} else {
// We purposefully ignore directories.
}
// Remove it from our "to do" list
remaining.erase(found);
}
// Determine if this is the place where we should insert
if ((AddBefore || InsertBefore) && RelPos == I->getPath().str())
insert_spot = I;
else if (AddAfter && RelPos == I->getPath().str()) {
insert_spot = I;
insert_spot++;
}
}
// If we didn't replace all the members, some will remain and need to be
// inserted at the previously computed insert-spot.
if (!remaining.empty()) {
for (std::set<sys::Path>::iterator PI = remaining.begin(),
PE = remaining.end(); PI != PE; ++PI) {
if (TheArchive->addFileBefore(*PI,insert_spot, ErrMsg))
return true;
}
}
// We're done editting, reconstruct the archive.
if (TheArchive->writeToDisk(SymTable,TruncateNames,Compression,ErrMsg))
return true;
if (ReallyVerbose)
printSymbolTable();
return false;
}
// main - main program for llvm-ar .. see comments in the code
int main(int argc, char **argv) {
// Print a stack trace if we signal out.
sys::PrintStackTraceOnErrorSignal();
PrettyStackTraceProgram X(argc, argv);
LLVMContext &Context = getGlobalContext();
llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
// Have the command line options parsed and handle things
// like --help and --version.
cl::ParseCommandLineOptions(argc, argv,
"LLVM Archiver (llvm-ar)\n\n"
" This program archives bitcode files into single libraries\n"
);
int exitCode = 0;
// Make sure we don't exit with "unhandled exception".
try {
// Do our own parsing of the command line because the CommandLine utility
// can't handle the grouped positional parameters without a dash.
ArchiveOperation Operation = parseCommandLine();
// Check the path name of the archive
sys::Path ArchivePath;
if (!ArchivePath.set(ArchiveName))
throw std::string("Archive name invalid: ") + ArchiveName;
// Create or open the archive object.
bool Exists;
if (llvm::sys::fs::exists(ArchivePath.str(), Exists) || !Exists) {
// Produce a warning if we should and we're creating the archive
if (!Create)
errs() << argv[0] << ": creating " << ArchivePath.str() << "\n";
TheArchive = Archive::CreateEmpty(ArchivePath, Context);
TheArchive->writeToDisk();
} else {
std::string Error;
TheArchive = Archive::OpenAndLoad(ArchivePath, Context, &Error);
if (TheArchive == 0) {
errs() << argv[0] << ": error loading '" << ArchivePath.str() << "': "
<< Error << "!\n";
return 1;
}
}
// Make sure we're not fooling ourselves.
assert(TheArchive && "Unable to instantiate the archive");
// Make sure we clean up the archive even on failure.
std::auto_ptr<Archive> AutoArchive(TheArchive);
// Perform the operation
std::string ErrMsg;
bool haveError = false;
switch (Operation) {
case Print: haveError = doPrint(&ErrMsg); break;
case Delete: haveError = doDelete(&ErrMsg); break;
case Move: haveError = doMove(&ErrMsg); break;
case QuickAppend: haveError = doQuickAppend(&ErrMsg); break;
case ReplaceOrInsert: haveError = doReplaceOrInsert(&ErrMsg); break;
case DisplayTable: haveError = doDisplayTable(&ErrMsg); break;
case Extract: haveError = doExtract(&ErrMsg); break;
case NoOperation:
errs() << argv[0] << ": No operation was selected.\n";
break;
}
if (haveError) {
errs() << argv[0] << ": " << ErrMsg << "\n";
return 1;
}
} catch (const char*msg) {
// These errors are usage errors, thrown only by the various checks in the
// code above.
errs() << argv[0] << ": " << msg << "\n\n";
cl::PrintHelpMessage();
exitCode = 1;
} catch (const std::string& msg) {
// These errors are thrown by LLVM libraries (e.g. lib System) and represent
// a more serious error so we bump the exitCode and don't print the usage.
errs() << argv[0] << ": " << msg << "\n";
exitCode = 2;
} catch (...) {
// This really shouldn't happen, but just in case ....
errs() << argv[0] << ": An unexpected unknown exception occurred.\n";
exitCode = 3;
}
// Return result code back to operating system.
return exitCode;
}