1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
|
//===- DriverDispatcher.cpp - Support using LLD as a library --------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "lld/Common/CommonLinkerContext.h"
#include "lld/Common/Driver.h"
#include "lld/Common/ErrorHandler.h"
#include "lld/Common/Memory.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/CrashRecoveryContext.h"
#include "llvm/Support/InitLLVM.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/Process.h"
#include "llvm/TargetParser/Host.h"
#include "llvm/TargetParser/Triple.h"
#include <cstdlib>
using namespace lld;
using namespace llvm;
using namespace llvm::sys;
static void err(const Twine &s) { llvm::errs() << s << "\n"; }
static Flavor getFlavor(StringRef s) {
return StringSwitch<Flavor>(s)
.CasesLower("ld", "ld.lld", "gnu", Gnu)
.CasesLower("wasm", "ld-wasm", Wasm)
.CaseLower("link", WinLink)
.CasesLower("ld64", "ld64.lld", "darwin", Darwin)
.Default(Invalid);
}
static cl::TokenizerCallback getDefaultQuotingStyle() {
if (Triple(sys::getProcessTriple()).getOS() == Triple::Win32)
return cl::TokenizeWindowsCommandLine;
return cl::TokenizeGNUCommandLine;
}
static bool isPETargetName(StringRef s) {
return s == "i386pe" || s == "i386pep" || s == "thumb2pe" || s == "arm64pe";
}
static std::optional<bool> isPETarget(llvm::ArrayRef<const char *> args) {
for (auto it = args.begin(); it + 1 != args.end(); ++it) {
if (StringRef(*it) != "-m")
continue;
return isPETargetName(*(it + 1));
}
// Expand response files (arguments in the form of @<filename>)
// to allow detecting the -m argument from arguments in them.
SmallVector<const char *, 256> expandedArgs(args.data(),
args.data() + args.size());
BumpPtrAllocator a;
StringSaver saver(a);
cl::ExpansionContext ectx(saver.getAllocator(), getDefaultQuotingStyle());
if (Error e = ectx.expandResponseFiles(expandedArgs)) {
err(toString(std::move(e)));
return std::nullopt;
}
for (auto it = expandedArgs.begin(); it + 1 != expandedArgs.end(); ++it) {
if (StringRef(*it) != "-m")
continue;
return isPETargetName(*(it + 1));
}
#ifdef LLD_DEFAULT_LD_LLD_IS_MINGW
return true;
#else
return false;
#endif
}
static Flavor parseProgname(StringRef progname) {
// Use GNU driver for "ld" by default.
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
parseFlavorWithoutMinGW(llvm::SmallVectorImpl<const char *> &argsV) {
// Parse -flavor option.
if (argsV.size() > 1 && argsV[1] == StringRef("-flavor")) {
if (argsV.size() <= 2) {
err("missing arg value for '-flavor'");
return Invalid;
}
Flavor f = getFlavor(argsV[2]);
if (f == Invalid) {
err("Unknown flavor: " + StringRef(argsV[2]));
return Invalid;
}
argsV.erase(argsV.begin() + 1, argsV.begin() + 3);
return f;
}
// Deduct the flavor from argv[0].
StringRef arg0 = path::filename(argsV[0]);
if (arg0.ends_with_insensitive(".exe"))
arg0 = arg0.drop_back(4);
Flavor f = parseProgname(arg0);
if (f == Invalid) {
err("lld is a generic driver.\n"
"Invoke ld.lld (Unix), ld64.lld (macOS), lld-link (Windows), wasm-ld"
" (WebAssembly) instead");
return Invalid;
}
return f;
}
static Flavor parseFlavor(llvm::SmallVectorImpl<const char *> &argsV) {
Flavor f = parseFlavorWithoutMinGW(argsV);
if (f == Gnu) {
auto isPE = isPETarget(argsV);
if (!isPE)
return Invalid;
if (*isPE)
return MinGW;
}
return f;
}
static Driver whichDriver(llvm::SmallVectorImpl<const char *> &argsV,
llvm::ArrayRef<DriverDef> drivers) {
Flavor f = parseFlavor(argsV);
auto it =
llvm::find_if(drivers, [=](auto &driverdef) { return driverdef.f == f; });
if (it == drivers.end()) {
// Driver is invalid or not available in this build.
return [](llvm::ArrayRef<const char *>, llvm::raw_ostream &,
llvm::raw_ostream &, bool, bool) { return false; };
}
return it->d;
}
namespace lld {
bool inTestOutputDisabled = false;
/// Universal linker main(). This linker emulates the gnu, darwin, or
/// windows linker based on the argv[0] or -flavor option.
int unsafeLldMain(llvm::ArrayRef<const char *> args,
llvm::raw_ostream &stdoutOS, llvm::raw_ostream &stderrOS,
llvm::ArrayRef<DriverDef> drivers, bool exitEarly) {
SmallVector<const char *, 256> argsV(args);
Driver d = whichDriver(argsV, drivers);
// Run the driver. If an error occurs, false will be returned.
int r = !d(argsV, stdoutOS, stderrOS, exitEarly, inTestOutputDisabled);
// At this point 'r' is either 1 for error, and 0 for no error.
// Call exit() if we can to avoid calling destructors.
if (exitEarly)
exitLld(r);
// Delete the global context and clear the global context pointer, so that it
// cannot be accessed anymore.
CommonLinkerContext::destroy();
return r;
}
} // namespace lld
Result lld::lldMain(llvm::ArrayRef<const char *> args,
llvm::raw_ostream &stdoutOS, llvm::raw_ostream &stderrOS,
llvm::ArrayRef<DriverDef> drivers) {
int r = 0;
{
// The crash recovery is here only to be able to recover from arbitrary
// control flow when fatal() is called (through setjmp/longjmp or
// __try/__except).
llvm::CrashRecoveryContext crc;
if (!crc.RunSafely([&]() {
r = unsafeLldMain(args, stdoutOS, stderrOS, drivers,
/*exitEarly=*/false);
}))
return {crc.RetCode, /*canRunAgain=*/false};
}
// Cleanup memory and reset everything back in pristine condition. This path
// is only taken when LLD is in test, or when it is used as a library.
llvm::CrashRecoveryContext crc;
if (!crc.RunSafely([&]() { CommonLinkerContext::destroy(); })) {
// The memory is corrupted beyond any possible recovery.
return {r, /*canRunAgain=*/false};
}
return {r, /*canRunAgain=*/true};
}
|
