1 //===--- tools/clang-repl/ClangRepl.cpp - clang-repl - the Clang REPL -----===//
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 // This file implements a REPL tool on top of clang.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "clang/Basic/Diagnostic.h"
14 #include "clang/Frontend/CompilerInstance.h"
15 #include "clang/Frontend/FrontendDiagnostic.h"
16 #include "clang/Interpreter/Interpreter.h"
17
18 #include "llvm/ExecutionEngine/Orc/LLJIT.h"
19 #include "llvm/LineEditor/LineEditor.h"
20 #include "llvm/Support/CommandLine.h"
21 #include "llvm/Support/ManagedStatic.h" // llvm_shutdown
22 #include "llvm/Support/Signals.h"
23 #include "llvm/Support/TargetSelect.h" // llvm::Initialize*
24
25 static llvm::cl::list<std::string>
26 ClangArgs("Xcc",
27 llvm::cl::desc("Argument to pass to the CompilerInvocation"),
28 llvm::cl::CommaSeparated);
29 static llvm::cl::opt<bool> OptHostSupportsJit("host-supports-jit",
30 llvm::cl::Hidden);
31 static llvm::cl::list<std::string> OptInputs(llvm::cl::Positional,
32 llvm::cl::desc("[code to run]"));
33
LLVMErrorHandler(void * UserData,const char * Message,bool GenCrashDiag)34 static void LLVMErrorHandler(void *UserData, const char *Message,
35 bool GenCrashDiag) {
36 auto &Diags = *static_cast<clang::DiagnosticsEngine *>(UserData);
37
38 Diags.Report(clang::diag::err_fe_error_backend) << Message;
39
40 // Run the interrupt handlers to make sure any special cleanups get done, in
41 // particular that we remove files registered with RemoveFileOnSignal.
42 llvm::sys::RunInterruptHandlers();
43
44 // We cannot recover from llvm errors. When reporting a fatal error, exit
45 // with status 70 to generate crash diagnostics. For BSD systems this is
46 // defined as an internal software error. Otherwise, exit with status 1.
47
48 exit(GenCrashDiag ? 70 : 1);
49 }
50
51 // If we are running with -verify a reported has to be returned as unsuccess.
52 // This is relevant especially for the test suite.
checkDiagErrors(const clang::CompilerInstance * CI)53 static int checkDiagErrors(const clang::CompilerInstance *CI) {
54 unsigned Errs = CI->getDiagnostics().getClient()->getNumErrors();
55 if (CI->getDiagnosticOpts().VerifyDiagnostics) {
56 // If there was an error that came from the verifier we must return 1 as
57 // an exit code for the process. This will make the test fail as expected.
58 clang::DiagnosticConsumer *Client = CI->getDiagnostics().getClient();
59 Client->EndSourceFile();
60 Errs = Client->getNumErrors();
61
62 // The interpreter expects BeginSourceFile/EndSourceFiles to be balanced.
63 Client->BeginSourceFile(CI->getLangOpts(), &CI->getPreprocessor());
64 }
65 return Errs ? EXIT_FAILURE : EXIT_SUCCESS;
66 }
67
68 llvm::ExitOnError ExitOnErr;
main(int argc,const char ** argv)69 int main(int argc, const char **argv) {
70 ExitOnErr.setBanner("clang-repl: ");
71 llvm::cl::ParseCommandLineOptions(argc, argv);
72
73 std::vector<const char *> ClangArgv(ClangArgs.size());
74 std::transform(ClangArgs.begin(), ClangArgs.end(), ClangArgv.begin(),
75 [](const std::string &s) -> const char * { return s.data(); });
76 llvm::InitializeNativeTarget();
77 llvm::InitializeNativeTargetAsmPrinter();
78
79 if (OptHostSupportsJit) {
80 auto J = llvm::orc::LLJITBuilder().create();
81 if (J)
82 llvm::outs() << "true\n";
83 else {
84 llvm::consumeError(J.takeError());
85 llvm::outs() << "false\n";
86 }
87 return 0;
88 }
89
90 // FIXME: Investigate if we could use runToolOnCodeWithArgs from tooling. It
91 // can replace the boilerplate code for creation of the compiler instance.
92 auto CI = ExitOnErr(clang::IncrementalCompilerBuilder::create(ClangArgv));
93
94 // Set an error handler, so that any LLVM backend diagnostics go through our
95 // error handler.
96 llvm::install_fatal_error_handler(LLVMErrorHandler,
97 static_cast<void *>(&CI->getDiagnostics()));
98
99 // Load any requested plugins.
100 CI->LoadRequestedPlugins();
101
102 auto Interp = ExitOnErr(clang::Interpreter::create(std::move(CI)));
103 for (const std::string &input : OptInputs) {
104 if (auto Err = Interp->ParseAndExecute(input))
105 llvm::logAllUnhandledErrors(std::move(Err), llvm::errs(), "error: ");
106 }
107
108 if (OptInputs.empty()) {
109 llvm::LineEditor LE("clang-repl");
110 // FIXME: Add LE.setListCompleter
111 while (llvm::Optional<std::string> Line = LE.readLine()) {
112 if (*Line == R"(%quit)")
113 break;
114 if (*Line == R"(%undo)") {
115 if (auto Err = Interp->Undo())
116 llvm::logAllUnhandledErrors(std::move(Err), llvm::errs(), "error: ");
117 continue;
118 }
119
120 if (auto Err = Interp->ParseAndExecute(*Line))
121 llvm::logAllUnhandledErrors(std::move(Err), llvm::errs(), "error: ");
122 }
123 }
124
125 // Our error handler depends on the Diagnostics object, which we're
126 // potentially about to delete. Uninstall the handler now so that any
127 // later errors use the default handling behavior instead.
128 llvm::remove_fatal_error_handler();
129
130 llvm::llvm_shutdown();
131
132 return checkDiagErrors(Interp->getCompilerInstance());
133 }
134