1 //===- ErrorHandler.cpp ---------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "lld/Common/ErrorHandler.h"
10 
11 #include "lld/Common/Threads.h"
12 
13 #include "llvm/ADT/Twine.h"
14 #include "llvm/IR/DiagnosticInfo.h"
15 #include "llvm/IR/DiagnosticPrinter.h"
16 #include "llvm/Support/ManagedStatic.h"
17 #include "llvm/Support/raw_ostream.h"
18 #include <mutex>
19 #include <regex>
20 
21 #if !defined(_MSC_VER) && !defined(__MINGW32__)
22 #include <unistd.h>
23 #endif
24 
25 using namespace llvm;
26 using namespace lld;
27 
28 // The functions defined in this file can be called from multiple threads,
29 // but lld::outs() or lld::errs() are not thread-safe. We protect them using a
30 // mutex.
31 static std::mutex mu;
32 
33 // We want to separate multi-line messages with a newline. `sep` is "\n"
34 // if the last messages was multi-line. Otherwise "".
35 static StringRef sep;
36 
37 static StringRef getSeparator(const Twine &msg) {
38   if (StringRef(msg.str()).contains('\n'))
39     return "\n";
40   return "";
41 }
42 
43 raw_ostream *lld::stdoutOS;
44 raw_ostream *lld::stderrOS;
45 
46 raw_ostream &lld::outs() { return stdoutOS ? *stdoutOS : llvm::outs(); }
47 raw_ostream &lld::errs() { return stderrOS ? *stderrOS : llvm::errs(); }
48 
49 ErrorHandler &lld::errorHandler() {
50   static ErrorHandler handler;
51   return handler;
52 }
53 
54 void lld::exitLld(int val) {
55   // Delete any temporary file, while keeping the memory mapping open.
56   if (errorHandler().outputBuffer)
57     errorHandler().outputBuffer->discard();
58 
59   // Dealloc/destroy ManagedStatic variables before calling
60   // _exit(). In a non-LTO build, this is a nop. In an LTO
61   // build allows us to get the output of -time-passes.
62   llvm_shutdown();
63 
64   lld::outs().flush();
65   lld::errs().flush();
66   _exit(val);
67 }
68 
69 void lld::diagnosticHandler(const DiagnosticInfo &di) {
70   SmallString<128> s;
71   raw_svector_ostream os(s);
72   DiagnosticPrinterRawOStream dp(os);
73   di.print(dp);
74   switch (di.getSeverity()) {
75   case DS_Error:
76     error(s);
77     break;
78   case DS_Warning:
79     warn(s);
80     break;
81   case DS_Remark:
82   case DS_Note:
83     message(s);
84     break;
85   }
86 }
87 
88 void lld::checkError(Error e) {
89   handleAllErrors(std::move(e),
90                   [&](ErrorInfoBase &eib) { error(eib.message()); });
91 }
92 
93 // This is for --vs-diagnostics.
94 //
95 // Normally, lld's error message starts with argv[0]. Therefore, it usually
96 // looks like this:
97 //
98 //   ld.lld: error: ...
99 //
100 // This error message style is unfortunately unfriendly to Visual Studio
101 // IDE. VS interprets the first word of the first line as an error location
102 // and make it clickable, thus "ld.lld" in the above message would become a
103 // clickable text. When you click it, VS opens "ld.lld" executable file with
104 // a binary editor.
105 //
106 // As a workaround, we print out an error location instead of "ld.lld" if
107 // lld is running in VS diagnostics mode. As a result, error message will
108 // look like this:
109 //
110 //   src/foo.c(35): error: ...
111 //
112 // This function returns an error location string. An error location is
113 // extracted from an error message using regexps.
114 std::string ErrorHandler::getLocation(const Twine &msg) {
115   if (!vsDiagnostics)
116     return logName;
117 
118   static std::regex regexes[] = {
119       std::regex(
120           R"(^undefined (?:\S+ )?symbol:.*\n)"
121           R"(>>> referenced by .+\((\S+):(\d+)\))"),
122       std::regex(
123           R"(^undefined (?:\S+ )?symbol:.*\n>>> referenced by (\S+):(\d+))"),
124       std::regex(R"(^undefined symbol:.*\n>>> referenced by (.*):)"),
125       std::regex(
126           R"(^duplicate symbol: .*\n>>> defined in (\S+)\n>>> defined in.*)"),
127       std::regex(
128           R"(^duplicate symbol: .*\n>>> defined at .+\((\S+):(\d+)\))"),
129       std::regex(R"(^duplicate symbol: .*\n>>> defined at (\S+):(\d+))"),
130       std::regex(
131           R"(.*\n>>> defined in .*\n>>> referenced by .+\((\S+):(\d+)\))"),
132       std::regex(R"(.*\n>>> defined in .*\n>>> referenced by (\S+):(\d+))"),
133       std::regex(R"((\S+):(\d+): unclosed quote)"),
134   };
135 
136   std::string str = msg.str();
137   for (std::regex &re : regexes) {
138     std::smatch m;
139     if (!std::regex_search(str, m, re))
140       continue;
141 
142     assert(m.size() == 2 || m.size() == 3);
143     if (m.size() == 2)
144       return m.str(1);
145     return m.str(1) + "(" + m.str(2) + ")";
146   }
147 
148   return logName;
149 }
150 
151 void ErrorHandler::log(const Twine &msg) {
152   if (!verbose)
153     return;
154   std::lock_guard<std::mutex> lock(mu);
155   lld::errs() << logName << ": " << msg << "\n";
156 }
157 
158 void ErrorHandler::message(const Twine &msg) {
159   std::lock_guard<std::mutex> lock(mu);
160   lld::outs() << msg << "\n";
161   lld::outs().flush();
162 }
163 
164 void ErrorHandler::warn(const Twine &msg) {
165   if (fatalWarnings) {
166     error(msg);
167     return;
168   }
169 
170   std::lock_guard<std::mutex> lock(mu);
171   lld::errs() << sep << getLocation(msg) << ": " << Colors::MAGENTA
172               << "warning: " << Colors::RESET << msg << "\n";
173   sep = getSeparator(msg);
174 }
175 
176 void ErrorHandler::error(const Twine &msg) {
177   // If Visual Studio-style error message mode is enabled,
178   // this particular error is printed out as two errors.
179   if (vsDiagnostics) {
180     static std::regex re(R"(^(duplicate symbol: .*))"
181                          R"((\n>>> defined at \S+:\d+.*\n>>>.*))"
182                          R"((\n>>> defined at \S+:\d+.*\n>>>.*))");
183     std::string str = msg.str();
184     std::smatch m;
185 
186     if (std::regex_match(str, m, re)) {
187       error(m.str(1) + m.str(2));
188       error(m.str(1) + m.str(3));
189       return;
190     }
191   }
192 
193   std::lock_guard<std::mutex> lock(mu);
194 
195   if (errorLimit == 0 || errorCount < errorLimit) {
196     lld::errs() << sep << getLocation(msg) << ": " << Colors::RED
197                 << "error: " << Colors::RESET << msg << "\n";
198   } else if (errorCount == errorLimit) {
199     lld::errs() << sep << getLocation(msg) << ": " << Colors::RED
200                 << "error: " << Colors::RESET << errorLimitExceededMsg << "\n";
201     if (exitEarly)
202       exitLld(1);
203   }
204 
205   sep = getSeparator(msg);
206   ++errorCount;
207 }
208 
209 void ErrorHandler::fatal(const Twine &msg) {
210   error(msg);
211   exitLld(1);
212 }
213