blob: 09f8079010d4b08120c1b4327749d2d143971776 [file] [log] [blame]
//===- tools/lld/lld.cpp - Linker Driver Dispatcher -----------------------===//
// The LLVM Linker
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
// This is the entry point to the lld driver. This is a thin wrapper which
// dispatches to the given platform specific driver.
// If there is -flavor option, it is dispatched according to the arguments.
// If the flavor parameter is not present, then it is dispatched according
// to argv[0].
#include "lld/Driver/Driver.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/PrettyStackTrace.h"
#include "llvm/Support/Signals.h"
using namespace lld;
using namespace llvm;
using namespace llvm::sys;
enum Flavor {
Gnu, // -flavor gnu
WinLink, // -flavor link
Darwin, // -flavor darwin
LLVM_ATTRIBUTE_NORETURN static void die(const Twine &S) {
errs() << S << "\n";
static Flavor getFlavor(StringRef S) {
return StringSwitch<Flavor>(S)
.CasesLower("ld", "ld.lld", "gnu", Gnu)
.CaseLower("link", WinLink)
.CaseLower("darwin", Darwin)
static Flavor parseProgname(StringRef Progname) {
#if __APPLE__
// Use Darwin driver for "ld" on Darwin.
if (Progname == "ld")
return Darwin;
// Use GNU driver for "ld" on other Unix-like system.
if (Progname == "ld")
return Gnu;
// Progname may be something like "lld-gnu". Parse it.
SmallVector<StringRef, 3> V;
Progname.split(V, "-");
for (StringRef S : V)
if (Flavor F = getFlavor(S))
return F;
return Invalid;
static Flavor parseFlavor(std::vector<const char *> &V) {
// Parse -flavor option.
if (V.size() > 1 && V[1] == StringRef("-flavor")) {
if (V.size() <= 2)
die("missing arg value for '-flavor'");
Flavor F = getFlavor(V[2]);
if (F == Invalid)
die("Unknown flavor: " + StringRef(V[2]));
V.erase(V.begin() + 1, V.begin() + 3);
return F;
// Deduct the flavor from argv[0].
StringRef Arg0 = path::filename(V[0]);
if (Arg0.endswith_lower(".exe"))
Arg0 = Arg0.drop_back(4);
return parseProgname(Arg0);
/// Universal linker main(). This linker emulates the gnu, darwin, or
/// windows linker based on the argv[0] or -flavor option.
int main(int Argc, const char **Argv) {
// Standard set up, so program fails gracefully.
PrettyStackTraceProgram StackPrinter(Argc, Argv);
llvm_shutdown_obj Shutdown;
std::vector<const char *> Args(Argv, Argv + Argc);
switch (parseFlavor(Args)) {
case Gnu:
return !elf::link(Args, true);
case WinLink:
return !coff::link(Args);
case Darwin:
return !mach_o::link(Args);
die("lld is a generic driver.\n"
"Invoke ld.lld (Unix), ld (macOS) or lld-link (Windows) instead.");