xref: /llvm-project/llvm/lib/Support/InitLLVM.cpp (revision 9cada109115ec67b573b988b5408b2caaaa2abf7)
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 #ifdef __MVS__
22 #include <unistd.h>
23 
24 void CleanupStdHandles(void *Cookie) {
25   llvm::raw_ostream *Outs = &llvm::outs(), *Errs = &llvm::errs();
26   Outs->flush();
27   Errs->flush();
28   llvm::restorezOSStdHandleAutoConversion(STDIN_FILENO);
29   llvm::restorezOSStdHandleAutoConversion(STDOUT_FILENO);
30   llvm::restorezOSStdHandleAutoConversion(STDERR_FILENO);
31 }
32 #endif
33 
34 using namespace llvm;
35 using namespace llvm::sys;
36 
37 InitLLVM::InitLLVM(int &Argc, const char **&Argv,
38                    bool InstallPipeSignalExitHandler) {
39 #ifndef NDEBUG
40   static std::atomic<bool> Initialized{false};
41   assert(!Initialized && "InitLLVM was already initialized!");
42   Initialized = true;
43 #endif
44 #ifdef __MVS__
45   // Bring stdin/stdout/stderr into a known state.
46   sys::AddSignalHandler(CleanupStdHandles, nullptr);
47 #endif
48   if (InstallPipeSignalExitHandler)
49     // The pipe signal handler must be installed before any other handlers are
50     // registered. This is because the Unix \ref RegisterHandlers function does
51     // not perform a sigaction() for SIGPIPE unless a one-shot handler is
52     // present, to allow long-lived processes (like lldb) to fully opt-out of
53     // llvm's SIGPIPE handling and ignore the signal safely.
54     sys::SetOneShotPipeSignalFunction(sys::DefaultOneShotPipeSignalHandler);
55   // Initialize the stack printer after installing the one-shot pipe signal
56   // handler, so we can perform a sigaction() for SIGPIPE on Unix if requested.
57   StackPrinter.emplace(Argc, Argv);
58   sys::PrintStackTraceOnErrorSignal(Argv[0]);
59   install_out_of_memory_new_handler();
60 
61 #ifdef __MVS__
62 
63   // We use UTF-8 as the internal character encoding. On z/OS, all external
64   // output is encoded in EBCDIC. In order to be able to read all
65   // error messages, we turn conversion to EBCDIC on for stderr fd.
66   std::string Banner = std::string(Argv[0]) + ": ";
67   ExitOnError ExitOnErr(Banner);
68 
69   // If turning on conversion for stderr fails then the error message
70   // may be garbled. There is no solution to this problem.
71   ExitOnErr(errorCodeToError(llvm::enablezOSAutoConversion(STDERR_FILENO)));
72   ExitOnErr(errorCodeToError(llvm::enablezOSAutoConversion(STDOUT_FILENO)));
73 #endif
74 
75 #ifdef _WIN32
76   // We use UTF-8 as the internal character encoding. On Windows,
77   // arguments passed to main() may not be encoded in UTF-8. In order
78   // to reliably detect encoding of command line arguments, we use an
79   // Windows API to obtain arguments, convert them to UTF-8, and then
80   // write them back to the Argv vector.
81   //
82   // There's probably other way to do the same thing (e.g. using
83   // wmain() instead of main()), but this way seems less intrusive
84   // than that.
85   std::string Banner = std::string(Argv[0]) + ": ";
86   ExitOnError ExitOnErr(Banner);
87 
88   ExitOnErr(errorCodeToError(windows::GetCommandLineArguments(Args, Alloc)));
89 
90   // GetCommandLineArguments doesn't terminate the vector with a
91   // nullptr.  Do it to make it compatible with the real argv.
92   Args.push_back(nullptr);
93 
94   Argc = Args.size() - 1;
95   Argv = Args.data();
96 #endif
97 }
98 
99 InitLLVM::~InitLLVM() {
100 #ifdef __MVS__
101   CleanupStdHandles(nullptr);
102 #endif
103   llvm_shutdown();
104 }
105