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 "llvm/Support/Parallel.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 _exit().
60   // In an LTO build, allows us to get the output of -time-passes.
61   // Ensures that the thread pool for the parallel algorithms is stopped to
62   // avoid intermittent crashes on Windows when exiting.
63   llvm_shutdown();
64 
65   {
66     std::lock_guard<std::mutex> lock(mu);
67     lld::outs().flush();
68     lld::errs().flush();
69   }
70   _exit(val);
71 }
72 
73 void lld::diagnosticHandler(const DiagnosticInfo &di) {
74   SmallString<128> s;
75   raw_svector_ostream os(s);
76   DiagnosticPrinterRawOStream dp(os);
77   di.print(dp);
78   switch (di.getSeverity()) {
79   case DS_Error:
80     error(s);
81     break;
82   case DS_Warning:
83     warn(s);
84     break;
85   case DS_Remark:
86   case DS_Note:
87     message(s);
88     break;
89   }
90 }
91 
92 void lld::checkError(Error e) {
93   handleAllErrors(std::move(e),
94                   [&](ErrorInfoBase &eib) { error(eib.message()); });
95 }
96 
97 // This is for --vs-diagnostics.
98 //
99 // Normally, lld's error message starts with argv[0]. Therefore, it usually
100 // looks like this:
101 //
102 //   ld.lld: error: ...
103 //
104 // This error message style is unfortunately unfriendly to Visual Studio
105 // IDE. VS interprets the first word of the first line as an error location
106 // and make it clickable, thus "ld.lld" in the above message would become a
107 // clickable text. When you click it, VS opens "ld.lld" executable file with
108 // a binary editor.
109 //
110 // As a workaround, we print out an error location instead of "ld.lld" if
111 // lld is running in VS diagnostics mode. As a result, error message will
112 // look like this:
113 //
114 //   src/foo.c(35): error: ...
115 //
116 // This function returns an error location string. An error location is
117 // extracted from an error message using regexps.
118 std::string ErrorHandler::getLocation(const Twine &msg) {
119   if (!vsDiagnostics)
120     return std::string(logName);
121 
122   static std::regex regexes[] = {
123       std::regex(
124           R"(^undefined (?:\S+ )?symbol:.*\n)"
125           R"(>>> referenced by .+\((\S+):(\d+)\))"),
126       std::regex(
127           R"(^undefined (?:\S+ )?symbol:.*\n>>> referenced by (\S+):(\d+))"),
128       std::regex(R"(^undefined symbol:.*\n>>> referenced by (.*):)"),
129       std::regex(
130           R"(^duplicate symbol: .*\n>>> defined in (\S+)\n>>> defined in.*)"),
131       std::regex(
132           R"(^duplicate symbol: .*\n>>> defined at .+\((\S+):(\d+)\))"),
133       std::regex(R"(^duplicate symbol: .*\n>>> defined at (\S+):(\d+))"),
134       std::regex(
135           R"(.*\n>>> defined in .*\n>>> referenced by .+\((\S+):(\d+)\))"),
136       std::regex(R"(.*\n>>> defined in .*\n>>> referenced by (\S+):(\d+))"),
137       std::regex(R"((\S+):(\d+): unclosed quote)"),
138   };
139 
140   std::string str = msg.str();
141   for (std::regex &re : regexes) {
142     std::smatch m;
143     if (!std::regex_search(str, m, re))
144       continue;
145 
146     assert(m.size() == 2 || m.size() == 3);
147     if (m.size() == 2)
148       return m.str(1);
149     return m.str(1) + "(" + m.str(2) + ")";
150   }
151 
152   return std::string(logName);
153 }
154 
155 void ErrorHandler::log(const Twine &msg) {
156   if (!verbose)
157     return;
158   std::lock_guard<std::mutex> lock(mu);
159   lld::errs() << logName << ": " << msg << "\n";
160 }
161 
162 void ErrorHandler::message(const Twine &msg) {
163   std::lock_guard<std::mutex> lock(mu);
164   lld::outs() << msg << "\n";
165   lld::outs().flush();
166 }
167 
168 void ErrorHandler::warn(const Twine &msg) {
169   if (fatalWarnings) {
170     error(msg);
171     return;
172   }
173 
174   std::lock_guard<std::mutex> lock(mu);
175   lld::errs() << sep << getLocation(msg) << ": " << Colors::MAGENTA
176               << "warning: " << Colors::RESET << msg << "\n";
177   sep = getSeparator(msg);
178 }
179 
180 void ErrorHandler::error(const Twine &msg) {
181   // If Visual Studio-style error message mode is enabled,
182   // this particular error is printed out as two errors.
183   if (vsDiagnostics) {
184     static std::regex re(R"(^(duplicate symbol: .*))"
185                          R"((\n>>> defined at \S+:\d+.*\n>>>.*))"
186                          R"((\n>>> defined at \S+:\d+.*\n>>>.*))");
187     std::string str = msg.str();
188     std::smatch m;
189 
190     if (std::regex_match(str, m, re)) {
191       error(m.str(1) + m.str(2));
192       error(m.str(1) + m.str(3));
193       return;
194     }
195   }
196 
197   bool exit = false;
198   {
199     std::lock_guard<std::mutex> lock(mu);
200 
201     if (errorLimit == 0 || errorCount < errorLimit) {
202       lld::errs() << sep << getLocation(msg) << ": " << Colors::RED
203                   << "error: " << Colors::RESET << msg << "\n";
204     } else if (errorCount == errorLimit) {
205       lld::errs() << sep << getLocation(msg) << ": " << Colors::RED
206                   << "error: " << Colors::RESET << errorLimitExceededMsg
207                   << "\n";
208       exit = exitEarly;
209     }
210 
211     sep = getSeparator(msg);
212     ++errorCount;
213   }
214 
215   if (exit)
216     exitLld(1);
217 }
218 
219 void ErrorHandler::fatal(const Twine &msg) {
220   error(msg);
221   exitLld(1);
222 }
223