1 files changed, 152 insertions, 0 deletions
diff --git a/clang/lib/Interpreter/IncrementalAction.cpp b/clang/lib/Interpreter/IncrementalAction.cpp
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index 000000000000..4d1bc4c59e85
--- /dev/null
+++ b/clang/lib/Interpreter/IncrementalAction.cpp
@@ -0,0 +1,152 @@
+//===--- IncrementalAction.h - Incremental Frontend Action -*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "IncrementalAction.h"
+
+#include "clang/AST/ASTConsumer.h"
+#include "clang/CodeGen/CodeGenAction.h"
+#include "clang/CodeGen/ModuleBuilder.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/FrontendOptions.h"
+#include "clang/FrontendTool/Utils.h"
+#include "clang/Interpreter/Interpreter.h"
+#include "clang/Lex/PreprocessorOptions.h"
+#include "clang/Sema/Sema.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Support/Error.h"
+#include "llvm/Support/ErrorHandling.h"
+
+namespace clang {
+IncrementalAction::IncrementalAction(CompilerInstance &Instance,
+                                     llvm::LLVMContext &LLVMCtx,
+                                     llvm::Error &Err, Interpreter &I,
+                                     std::unique_ptr<ASTConsumer> Consumer)
+    : WrapperFrontendAction([&]() {
+        llvm::ErrorAsOutParameter EAO(&Err);
+        std::unique_ptr<FrontendAction> Act;
+        switch (Instance.getFrontendOpts().ProgramAction) {
+        default:
+          Err = llvm::createStringError(
+              std::errc::state_not_recoverable,
+              "Driver initialization failed. "
+              "Incremental mode for action %d is not supported",
+              Instance.getFrontendOpts().ProgramAction);
+          return Act;
+        case frontend::ASTDump:
+        case frontend::ASTPrint:
+        case frontend::ParseSyntaxOnly:
+          Act = CreateFrontendAction(Instance);
+          break;
+        case frontend::PluginAction:
+        case frontend::EmitAssembly:
+        case frontend::EmitBC:
+        case frontend::EmitObj:
+        case frontend::PrintPreprocessedInput:
+        case frontend::EmitLLVMOnly:
+          Act.reset(new EmitLLVMOnlyAction(&LLVMCtx));
+          break;
+        }
+        return Act;
+      }()),
+      Interp(I), CI(Instance), Consumer(std::move(Consumer)) {}
+
+std::unique_ptr<ASTConsumer>
+IncrementalAction::CreateASTConsumer(CompilerInstance & /*CI*/,
+                                     StringRef InFile) {
+  std::unique_ptr<ASTConsumer> C =
+      WrapperFrontendAction::CreateASTConsumer(this->CI, InFile);
+
+  if (Consumer) {
+    std::vector<std::unique_ptr<ASTConsumer>> Cs;
+    Cs.push_back(std::move(Consumer));
+    Cs.push_back(std::move(C));
+    return std::make_unique<MultiplexConsumer>(std::move(Cs));
+  }
+
+  return std::make_unique<InProcessPrintingASTConsumer>(std::move(C), Interp);
+}
+
+void IncrementalAction::ExecuteAction() {
+  WrapperFrontendAction::ExecuteAction();
+  getCompilerInstance().getSema().CurContext = nullptr;
+}
+
+void IncrementalAction::EndSourceFile() {
+  if (IsTerminating && getWrapped())
+    WrapperFrontendAction::EndSourceFile();
+}
+
+void IncrementalAction::FinalizeAction() {
+  assert(!IsTerminating && "Already finalized!");
+  IsTerminating = true;
+  EndSourceFile();
+}
+
+void IncrementalAction::CacheCodeGenModule() {
+  CachedInCodeGenModule = GenModule();
+}
+
+llvm::Module *IncrementalAction::getCachedCodeGenModule() const {
+  return CachedInCodeGenModule.get();
+}
+
+std::unique_ptr<llvm::Module> IncrementalAction::GenModule() {
+  static unsigned ID = 0;
+  if (CodeGenerator *CG = getCodeGen()) {
+    // Clang's CodeGen is designed to work with a single llvm::Module. In many
+    // cases for convenience various CodeGen parts have a reference to the
+    // llvm::Module (TheModule or Module) which does not change when a new
+    // module is pushed. However, the execution engine wants to take ownership
+    // of the module which does not map well to CodeGen's design. To work this
+    // around we created an empty module to make CodeGen happy. We should make
+    // sure it always stays empty.
+    assert(((!CachedInCodeGenModule ||
+             !CI.getPreprocessorOpts().Includes.empty()) ||
+            (CachedInCodeGenModule->empty() &&
+             CachedInCodeGenModule->global_empty() &&
+             CachedInCodeGenModule->alias_empty() &&
+             CachedInCodeGenModule->ifunc_empty())) &&
+           "CodeGen wrote to a readonly module");
+    std::unique_ptr<llvm::Module> M(CG->ReleaseModule());
+    CG->StartModule("incr_module_" + std::to_string(ID++), M->getContext());
+    return M;
+  }
+  return nullptr;
+}
+
+CodeGenerator *IncrementalAction::getCodeGen() const {
+  FrontendAction *WrappedAct = getWrapped();
+  if (!WrappedAct || !WrappedAct->hasIRSupport())
+    return nullptr;
+  return static_cast<CodeGenAction *>(WrappedAct)->getCodeGenerator();
+}
+
+InProcessPrintingASTConsumer::InProcessPrintingASTConsumer(
+    std::unique_ptr<ASTConsumer> C, Interpreter &I)
+    : MultiplexConsumer(std::move(C)), Interp(I) {}
+
+bool InProcessPrintingASTConsumer::HandleTopLevelDecl(DeclGroupRef DGR) {
+  if (DGR.isNull())
+    return true;
+
+  for (Decl *D : DGR)
+    if (auto *TLSD = llvm::dyn_cast<TopLevelStmtDecl>(D))
+      if (TLSD && TLSD->isSemiMissing()) {
+        auto ExprOrErr = Interp.convertExprToValue(cast<Expr>(TLSD->getStmt()));
+        if (llvm::Error E = ExprOrErr.takeError()) {
+          llvm::logAllUnhandledErrors(std::move(E), llvm::errs(),
+                                      "Value printing failed: ");
+          return false; // abort parsing
+        }
+        TLSD->setStmt(*ExprOrErr);
+      }
+
+  return MultiplexConsumer::HandleTopLevelDecl(DGR);
+}
+
+} // namespace clang