1 //===------ Interpreter.cpp - Incremental Compilation and Execution -------===//
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 the component which performs incremental code
10 // compilation and execution.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/Interpreter/Interpreter.h"
15 
16 #include "IncrementalExecutor.h"
17 #include "IncrementalParser.h"
18 
19 #include "clang/AST/ASTContext.h"
20 #include "clang/Basic/TargetInfo.h"
21 #include "clang/CodeGen/ModuleBuilder.h"
22 #include "clang/CodeGen/ObjectFilePCHContainerOperations.h"
23 #include "clang/Driver/Compilation.h"
24 #include "clang/Driver/Driver.h"
25 #include "clang/Driver/Job.h"
26 #include "clang/Driver/Options.h"
27 #include "clang/Driver/Tool.h"
28 #include "clang/Frontend/CompilerInstance.h"
29 #include "clang/Frontend/TextDiagnosticBuffer.h"
30 #include "clang/Lex/PreprocessorOptions.h"
31 
32 #include "llvm/IR/Module.h"
33 #include "llvm/Support/Host.h"
34 
35 using namespace clang;
36 
37 // FIXME: Figure out how to unify with namespace init_convenience from
38 //        tools/clang-import-test/clang-import-test.cpp and
39 //        examples/clang-interpreter/main.cpp
40 namespace {
41 /// Retrieves the clang CC1 specific flags out of the compilation's jobs.
42 /// \returns NULL on error.
43 static llvm::Expected<const llvm::opt::ArgStringList *>
44 GetCC1Arguments(DiagnosticsEngine *Diagnostics,
45                 driver::Compilation *Compilation) {
46   // We expect to get back exactly one Command job, if we didn't something
47   // failed. Extract that job from the Compilation.
48   const driver::JobList &Jobs = Compilation->getJobs();
49   if (!Jobs.size() || !isa<driver::Command>(*Jobs.begin()))
50     return llvm::createStringError(std::errc::state_not_recoverable,
51                                    "Driver initialization failed. "
52                                    "Unable to create a driver job");
53 
54   // The one job we find should be to invoke clang again.
55   const driver::Command *Cmd = cast<driver::Command>(&(*Jobs.begin()));
56   if (llvm::StringRef(Cmd->getCreator().getName()) != "clang")
57     return llvm::createStringError(std::errc::state_not_recoverable,
58                                    "Driver initialization failed");
59 
60   return &Cmd->getArguments();
61 }
62 
63 static llvm::Expected<std::unique_ptr<CompilerInstance>>
64 CreateCI(const llvm::opt::ArgStringList &Argv) {
65   std::unique_ptr<CompilerInstance> Clang(new CompilerInstance());
66   IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
67 
68   // Register the support for object-file-wrapped Clang modules.
69   // FIXME: Clang should register these container operations automatically.
70   auto PCHOps = Clang->getPCHContainerOperations();
71   PCHOps->registerWriter(std::make_unique<ObjectFilePCHContainerWriter>());
72   PCHOps->registerReader(std::make_unique<ObjectFilePCHContainerReader>());
73 
74   // Buffer diagnostics from argument parsing so that we can output them using
75   // a well formed diagnostic object.
76   IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
77   TextDiagnosticBuffer *DiagsBuffer = new TextDiagnosticBuffer;
78   DiagnosticsEngine Diags(DiagID, &*DiagOpts, DiagsBuffer);
79   bool Success = CompilerInvocation::CreateFromArgs(
80       Clang->getInvocation(), llvm::makeArrayRef(Argv.begin(), Argv.size()),
81       Diags);
82 
83   // Infer the builtin include path if unspecified.
84   if (Clang->getHeaderSearchOpts().UseBuiltinIncludes &&
85       Clang->getHeaderSearchOpts().ResourceDir.empty())
86     Clang->getHeaderSearchOpts().ResourceDir =
87         CompilerInvocation::GetResourcesPath(Argv[0], nullptr);
88 
89   // Create the actual diagnostics engine.
90   Clang->createDiagnostics();
91   if (!Clang->hasDiagnostics())
92     return llvm::createStringError(std::errc::state_not_recoverable,
93                                    "Initialization failed. "
94                                    "Unable to create diagnostics engine");
95 
96   DiagsBuffer->FlushDiagnostics(Clang->getDiagnostics());
97   if (!Success)
98     return llvm::createStringError(std::errc::state_not_recoverable,
99                                    "Initialization failed. "
100                                    "Unable to flush diagnostics");
101 
102   // FIXME: Merge with CompilerInstance::ExecuteAction.
103   llvm::MemoryBuffer *MB = llvm::MemoryBuffer::getMemBuffer("").release();
104   Clang->getPreprocessorOpts().addRemappedFile("<<< inputs >>>", MB);
105 
106   Clang->setTarget(TargetInfo::CreateTargetInfo(
107       Clang->getDiagnostics(), Clang->getInvocation().TargetOpts));
108   if (!Clang->hasTarget())
109     return llvm::createStringError(std::errc::state_not_recoverable,
110                                    "Initialization failed. "
111                                    "Target is missing");
112 
113   Clang->getTarget().adjust(Clang->getDiagnostics(), Clang->getLangOpts());
114 
115   return std::move(Clang);
116 }
117 
118 } // anonymous namespace
119 
120 llvm::Expected<std::unique_ptr<CompilerInstance>>
121 IncrementalCompilerBuilder::create(std::vector<const char *> &ClangArgv) {
122 
123   // If we don't know ClangArgv0 or the address of main() at this point, try
124   // to guess it anyway (it's possible on some platforms).
125   std::string MainExecutableName =
126       llvm::sys::fs::getMainExecutable(nullptr, nullptr);
127 
128   ClangArgv.insert(ClangArgv.begin(), MainExecutableName.c_str());
129 
130   // Prepending -c to force the driver to do something if no action was
131   // specified. By prepending we allow users to override the default
132   // action and use other actions in incremental mode.
133   // FIXME: Print proper driver diagnostics if the driver flags are wrong.
134   ClangArgv.insert(ClangArgv.begin() + 1, "-c");
135 
136   if (!llvm::is_contained(ClangArgv, " -x")) {
137     // We do C++ by default; append right after argv[0] if no "-x" given
138     ClangArgv.push_back("-x");
139     ClangArgv.push_back("c++");
140   }
141 
142   // Put a dummy C++ file on to ensure there's at least one compile job for the
143   // driver to construct.
144   ClangArgv.push_back("<<< inputs >>>");
145 
146   CompilerInvocation Invocation;
147   // Buffer diagnostics from argument parsing so that we can output them using a
148   // well formed diagnostic object.
149   IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
150   IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
151   TextDiagnosticBuffer *DiagsBuffer = new TextDiagnosticBuffer;
152   DiagnosticsEngine Diags(DiagID, &*DiagOpts, DiagsBuffer);
153   unsigned MissingArgIndex, MissingArgCount;
154   const llvm::opt::OptTable &Opts = driver::getDriverOptTable();
155   llvm::opt::InputArgList ParsedArgs =
156       Opts.ParseArgs(ArrayRef<const char *>(ClangArgv).slice(1),
157                      MissingArgIndex, MissingArgCount);
158   ParseDiagnosticArgs(*DiagOpts, ParsedArgs, &Diags);
159 
160   driver::Driver Driver(/*MainBinaryName=*/ClangArgv[0],
161                         llvm::sys::getProcessTriple(), Diags);
162   Driver.setCheckInputsExist(false); // the input comes from mem buffers
163   llvm::ArrayRef<const char *> RF = llvm::makeArrayRef(ClangArgv);
164   std::unique_ptr<driver::Compilation> Compilation(Driver.BuildCompilation(RF));
165 
166   if (Compilation->getArgs().hasArg(driver::options::OPT_v))
167     Compilation->getJobs().Print(llvm::errs(), "\n", /*Quote=*/false);
168 
169   auto ErrOrCC1Args = GetCC1Arguments(&Diags, Compilation.get());
170   if (auto Err = ErrOrCC1Args.takeError())
171     return std::move(Err);
172 
173   return CreateCI(**ErrOrCC1Args);
174 }
175 
176 Interpreter::Interpreter(std::unique_ptr<CompilerInstance> CI,
177                          llvm::Error &Err) {
178   llvm::ErrorAsOutParameter EAO(&Err);
179   auto LLVMCtx = std::make_unique<llvm::LLVMContext>();
180   TSCtx = std::make_unique<llvm::orc::ThreadSafeContext>(std::move(LLVMCtx));
181   IncrParser = std::make_unique<IncrementalParser>(std::move(CI),
182                                                    *TSCtx->getContext(), Err);
183 }
184 
185 Interpreter::~Interpreter() {}
186 
187 llvm::Expected<std::unique_ptr<Interpreter>>
188 Interpreter::create(std::unique_ptr<CompilerInstance> CI) {
189   llvm::Error Err = llvm::Error::success();
190   auto Interp =
191       std::unique_ptr<Interpreter>(new Interpreter(std::move(CI), Err));
192   if (Err)
193     return std::move(Err);
194   return std::move(Interp);
195 }
196 
197 const CompilerInstance *Interpreter::getCompilerInstance() const {
198   return IncrParser->getCI();
199 }
200 
201 llvm::Expected<PartialTranslationUnit &>
202 Interpreter::Parse(llvm::StringRef Code) {
203   return IncrParser->Parse(Code);
204 }
205 
206 llvm::Error Interpreter::Execute(PartialTranslationUnit &T) {
207   assert(T.TheModule);
208   if (!IncrExecutor) {
209     const llvm::Triple &Triple =
210         getCompilerInstance()->getASTContext().getTargetInfo().getTriple();
211     llvm::Error Err = llvm::Error::success();
212     IncrExecutor = std::make_unique<IncrementalExecutor>(*TSCtx, Err, Triple);
213 
214     if (Err)
215       return Err;
216   }
217   // FIXME: Add a callback to retain the llvm::Module once the JIT is done.
218   if (auto Err = IncrExecutor->addModule(std::move(T.TheModule)))
219     return Err;
220 
221   if (auto Err = IncrExecutor->runCtors())
222     return Err;
223 
224   return llvm::Error::success();
225 }
226