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/Errc.h"
34 #include "llvm/Support/Host.h"
35 
36 using namespace clang;
37 
38 // FIXME: Figure out how to unify with namespace init_convenience from
39 //        tools/clang-import-test/clang-import-test.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(llvm::errc::not_supported,
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(llvm::errc::not_supported,
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::ArrayRef(Argv.begin(), Argv.size()), Diags);
81 
82   // Infer the builtin include path if unspecified.
83   if (Clang->getHeaderSearchOpts().UseBuiltinIncludes &&
84       Clang->getHeaderSearchOpts().ResourceDir.empty())
85     Clang->getHeaderSearchOpts().ResourceDir =
86         CompilerInvocation::GetResourcesPath(Argv[0], nullptr);
87 
88   // Create the actual diagnostics engine.
89   Clang->createDiagnostics();
90   if (!Clang->hasDiagnostics())
91     return llvm::createStringError(llvm::errc::not_supported,
92                                    "Initialization failed. "
93                                    "Unable to create diagnostics engine");
94 
95   DiagsBuffer->FlushDiagnostics(Clang->getDiagnostics());
96   if (!Success)
97     return llvm::createStringError(llvm::errc::not_supported,
98                                    "Initialization failed. "
99                                    "Unable to flush diagnostics");
100 
101   // FIXME: Merge with CompilerInstance::ExecuteAction.
102   llvm::MemoryBuffer *MB = llvm::MemoryBuffer::getMemBuffer("").release();
103   Clang->getPreprocessorOpts().addRemappedFile("<<< inputs >>>", MB);
104 
105   Clang->setTarget(TargetInfo::CreateTargetInfo(
106       Clang->getDiagnostics(), Clang->getInvocation().TargetOpts));
107   if (!Clang->hasTarget())
108     return llvm::createStringError(llvm::errc::not_supported,
109                                    "Initialization failed. "
110                                    "Target is missing");
111 
112   Clang->getTarget().adjust(Clang->getDiagnostics(), Clang->getLangOpts());
113 
114   // Don't clear the AST before backend codegen since we do codegen multiple
115   // times, reusing the same AST.
116   Clang->getCodeGenOpts().ClearASTBeforeBackend = false;
117 
118   Clang->getFrontendOpts().DisableFree = false;
119   Clang->getCodeGenOpts().DisableFree = false;
120 
121   return std::move(Clang);
122 }
123 
124 } // anonymous namespace
125 
126 llvm::Expected<std::unique_ptr<CompilerInstance>>
127 IncrementalCompilerBuilder::create(std::vector<const char *> &ClangArgv) {
128 
129   // If we don't know ClangArgv0 or the address of main() at this point, try
130   // to guess it anyway (it's possible on some platforms).
131   std::string MainExecutableName =
132       llvm::sys::fs::getMainExecutable(nullptr, nullptr);
133 
134   ClangArgv.insert(ClangArgv.begin(), MainExecutableName.c_str());
135 
136   // Prepending -c to force the driver to do something if no action was
137   // specified. By prepending we allow users to override the default
138   // action and use other actions in incremental mode.
139   // FIXME: Print proper driver diagnostics if the driver flags are wrong.
140   // We do C++ by default; append right after argv[0] if no "-x" given
141   ClangArgv.insert(ClangArgv.end(), "-xc++");
142   ClangArgv.insert(ClangArgv.end(), "-Xclang");
143   ClangArgv.insert(ClangArgv.end(), "-fincremental-extensions");
144   ClangArgv.insert(ClangArgv.end(), "-c");
145 
146   // Put a dummy C++ file on to ensure there's at least one compile job for the
147   // driver to construct.
148   ClangArgv.push_back("<<< inputs >>>");
149 
150   // Buffer diagnostics from argument parsing so that we can output them using a
151   // well formed diagnostic object.
152   IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
153   IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts =
154       CreateAndPopulateDiagOpts(ClangArgv);
155   TextDiagnosticBuffer *DiagsBuffer = new TextDiagnosticBuffer;
156   DiagnosticsEngine Diags(DiagID, &*DiagOpts, DiagsBuffer);
157 
158   driver::Driver Driver(/*MainBinaryName=*/ClangArgv[0],
159                         llvm::sys::getProcessTriple(), Diags);
160   Driver.setCheckInputsExist(false); // the input comes from mem buffers
161   llvm::ArrayRef<const char *> RF = llvm::ArrayRef(ClangArgv);
162   std::unique_ptr<driver::Compilation> Compilation(Driver.BuildCompilation(RF));
163 
164   if (Compilation->getArgs().hasArg(driver::options::OPT_v))
165     Compilation->getJobs().Print(llvm::errs(), "\n", /*Quote=*/false);
166 
167   auto ErrOrCC1Args = GetCC1Arguments(&Diags, Compilation.get());
168   if (auto Err = ErrOrCC1Args.takeError())
169     return std::move(Err);
170 
171   return CreateCI(**ErrOrCC1Args);
172 }
173 
174 Interpreter::Interpreter(std::unique_ptr<CompilerInstance> CI,
175                          llvm::Error &Err) {
176   llvm::ErrorAsOutParameter EAO(&Err);
177   auto LLVMCtx = std::make_unique<llvm::LLVMContext>();
178   TSCtx = std::make_unique<llvm::orc::ThreadSafeContext>(std::move(LLVMCtx));
179   IncrParser = std::make_unique<IncrementalParser>(std::move(CI),
180                                                    *TSCtx->getContext(), Err);
181 }
182 
183 Interpreter::~Interpreter() {
184   if (IncrExecutor) {
185     if (llvm::Error Err = IncrExecutor->cleanUp())
186       llvm::report_fatal_error(
187           llvm::Twine("Failed to clean up IncrementalExecutor: ") +
188           toString(std::move(Err)));
189   }
190 }
191 
192 llvm::Expected<std::unique_ptr<Interpreter>>
193 Interpreter::create(std::unique_ptr<CompilerInstance> CI) {
194   llvm::Error Err = llvm::Error::success();
195   auto Interp =
196       std::unique_ptr<Interpreter>(new Interpreter(std::move(CI), Err));
197   if (Err)
198     return std::move(Err);
199   return std::move(Interp);
200 }
201 
202 const CompilerInstance *Interpreter::getCompilerInstance() const {
203   return IncrParser->getCI();
204 }
205 
206 const llvm::orc::LLJIT *Interpreter::getExecutionEngine() const {
207   if (IncrExecutor)
208     return IncrExecutor->getExecutionEngine();
209   return nullptr;
210 }
211 
212 llvm::Expected<PartialTranslationUnit &>
213 Interpreter::Parse(llvm::StringRef Code) {
214   return IncrParser->Parse(Code);
215 }
216 
217 llvm::Error Interpreter::Execute(PartialTranslationUnit &T) {
218   assert(T.TheModule);
219   if (!IncrExecutor) {
220     const clang::TargetInfo &TI =
221         getCompilerInstance()->getASTContext().getTargetInfo();
222     llvm::Error Err = llvm::Error::success();
223     IncrExecutor = std::make_unique<IncrementalExecutor>(*TSCtx, Err, TI);
224 
225     if (Err)
226       return Err;
227   }
228   // FIXME: Add a callback to retain the llvm::Module once the JIT is done.
229   if (auto Err = IncrExecutor->addModule(T))
230     return Err;
231 
232   if (auto Err = IncrExecutor->runCtors())
233     return Err;
234 
235   return llvm::Error::success();
236 }
237 
238 llvm::Expected<llvm::JITTargetAddress>
239 Interpreter::getSymbolAddress(GlobalDecl GD) const {
240   if (!IncrExecutor)
241     return llvm::make_error<llvm::StringError>("Operation failed. "
242                                                "No execution engine",
243                                                std::error_code());
244   llvm::StringRef MangledName = IncrParser->GetMangledName(GD);
245   return getSymbolAddress(MangledName);
246 }
247 
248 llvm::Expected<llvm::JITTargetAddress>
249 Interpreter::getSymbolAddress(llvm::StringRef IRName) const {
250   if (!IncrExecutor)
251     return llvm::make_error<llvm::StringError>("Operation failed. "
252                                                "No execution engine",
253                                                std::error_code());
254 
255   return IncrExecutor->getSymbolAddress(IRName, IncrementalExecutor::IRName);
256 }
257 
258 llvm::Expected<llvm::JITTargetAddress>
259 Interpreter::getSymbolAddressFromLinkerName(llvm::StringRef Name) const {
260   if (!IncrExecutor)
261     return llvm::make_error<llvm::StringError>("Operation failed. "
262                                                "No execution engine",
263                                                std::error_code());
264 
265   return IncrExecutor->getSymbolAddress(Name, IncrementalExecutor::LinkerName);
266 }
267 
268 llvm::Error Interpreter::Undo(unsigned N) {
269 
270   std::list<PartialTranslationUnit> &PTUs = IncrParser->getPTUs();
271   if (N > PTUs.size())
272     return llvm::make_error<llvm::StringError>("Operation failed. "
273                                                "Too many undos",
274                                                std::error_code());
275   for (unsigned I = 0; I < N; I++) {
276     if (IncrExecutor) {
277       if (llvm::Error Err = IncrExecutor->removeModule(PTUs.back()))
278         return Err;
279     }
280 
281     IncrParser->CleanUpPTU(PTUs.back());
282     PTUs.pop_back();
283   }
284   return llvm::Error::success();
285 }
286