xref: /freebsd/contrib/llvm-project/llvm/lib/Support/InitLLVM.cpp (revision 770cf0a5f02dc8983a89c6568d741fbc25baa999)
1 //===-- InitLLVM.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 "llvm/Support/InitLLVM.h"
10 #include "llvm/ADT/StringRef.h"
11 #include "llvm/Support/AutoConvert.h"
12 #include "llvm/Support/Error.h"
13 #include "llvm/Support/ErrorHandling.h"
14 #include "llvm/Support/ManagedStatic.h"
15 #include "llvm/Support/Signals.h"
16 
17 #ifdef _WIN32
18 #include "llvm/Support/Windows/WindowsSupport.h"
19 #endif
20 
21 #if defined(HAVE_UNISTD_H)
22 #include <unistd.h>
23 #else
24 #ifndef STDIN_FILENO
25 #define STDIN_FILENO 0
26 #endif
27 #ifndef STDOUT_FILENO
28 #define STDOUT_FILENO 1
29 #endif
30 #ifndef STDERR_FILENO
31 #define STDERR_FILENO 2
32 #endif
33 #endif
34 
35 void CleanupStdHandles(void *Cookie) {
36   llvm::raw_ostream *Outs = &llvm::outs(), *Errs = &llvm::errs();
37   Outs->flush();
38   Errs->flush();
39   llvm::restoreStdHandleAutoConversion(STDIN_FILENO);
40   llvm::restoreStdHandleAutoConversion(STDOUT_FILENO);
41   llvm::restoreStdHandleAutoConversion(STDERR_FILENO);
42 }
43 
44 using namespace llvm;
45 using namespace llvm::sys;
46 
47 InitLLVM::InitLLVM(int &Argc, const char **&Argv,
48                    bool InstallPipeSignalExitHandler) {
49 #ifndef NDEBUG
50   static std::atomic<bool> Initialized{false};
51   assert(!Initialized && "InitLLVM was already initialized!");
52   Initialized = true;
53 #endif
54 
55   // Bring stdin/stdout/stderr into a known state.
56   sys::AddSignalHandler(CleanupStdHandles, nullptr);
57 
58   if (InstallPipeSignalExitHandler)
59     // The pipe signal handler must be installed before any other handlers are
60     // registered. This is because the Unix \ref RegisterHandlers function does
61     // not perform a sigaction() for SIGPIPE unless a one-shot handler is
62     // present, to allow long-lived processes (like lldb) to fully opt-out of
63     // llvm's SIGPIPE handling and ignore the signal safely.
64     sys::SetOneShotPipeSignalFunction(sys::DefaultOneShotPipeSignalHandler);
65   // Initialize the stack printer after installing the one-shot pipe signal
66   // handler, so we can perform a sigaction() for SIGPIPE on Unix if requested.
67   StackPrinter.emplace(Argc, Argv);
68   sys::PrintStackTraceOnErrorSignal(Argv[0]);
69   install_out_of_memory_new_handler();
70 
71 #ifdef __MVS__
72 
73   // We use UTF-8 as the internal character encoding. On z/OS, all external
74   // output is encoded in EBCDIC. In order to be able to read all
75   // error messages, we turn conversion to EBCDIC on for stderr fd.
76   std::string Banner = std::string(Argv[0]) + ": ";
77   ExitOnError ExitOnErr(Banner);
78 
79   // If turning on conversion for stderr fails then the error message
80   // may be garbled. There is no solution to this problem.
81   ExitOnErr(errorCodeToError(llvm::enableAutoConversion(STDERR_FILENO)));
82   ExitOnErr(errorCodeToError(llvm::enableAutoConversion(STDOUT_FILENO)));
83 #endif
84 
85 #ifdef _WIN32
86   // We use UTF-8 as the internal character encoding. On Windows,
87   // arguments passed to main() may not be encoded in UTF-8. In order
88   // to reliably detect encoding of command line arguments, we use an
89   // Windows API to obtain arguments, convert them to UTF-8, and then
90   // write them back to the Argv vector.
91   //
92   // There's probably other way to do the same thing (e.g. using
93   // wmain() instead of main()), but this way seems less intrusive
94   // than that.
95   std::string Banner = std::string(Argv[0]) + ": ";
96   ExitOnError ExitOnErr(Banner);
97 
98   ExitOnErr(errorCodeToError(windows::GetCommandLineArguments(Args, Alloc)));
99 
100   // GetCommandLineArguments doesn't terminate the vector with a
101   // nullptr.  Do it to make it compatible with the real argv.
102   Args.push_back(nullptr);
103 
104   Argc = Args.size() - 1;
105   Argv = Args.data();
106 #endif
107 }
108 
109 InitLLVM::~InitLLVM() {
110   CleanupStdHandles(nullptr);
111   llvm_shutdown();
112 }
113