1 files changed, 114 insertions, 0 deletions
diff --git a/contrib/llvm-project/clang/lib/Frontend/ASTMerge.cpp b/contrib/llvm-project/clang/lib/Frontend/ASTMerge.cpp
new file mode 100644
index 000000000000..14d781ccdf93
--- /dev/null
+++ b/contrib/llvm-project/clang/lib/Frontend/ASTMerge.cpp
@@ -0,0 +1,114 @@
+//===-- ASTMerge.cpp - AST Merging 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 "clang/Frontend/ASTUnit.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/ASTDiagnostic.h"
+#include "clang/AST/ASTImporter.h"
+#include "clang/AST/ASTImporterSharedState.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Frontend/CompilerInstance.h"
+#include "clang/Frontend/FrontendActions.h"
+
+using namespace clang;
+
+std::unique_ptr<ASTConsumer>
+ASTMergeAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
+  return AdaptedAction->CreateASTConsumer(CI, InFile);
+}
+
+bool ASTMergeAction::BeginSourceFileAction(CompilerInstance &CI) {
+  // FIXME: This is a hack. We need a better way to communicate the
+  // AST file, compiler instance, and file name than member variables
+  // of FrontendAction.
+  AdaptedAction->setCurrentInput(getCurrentInput(), takeCurrentASTUnit());
+  AdaptedAction->setCompilerInstance(&CI);
+  return AdaptedAction->BeginSourceFileAction(CI);
+}
+
+void ASTMergeAction::ExecuteAction() {
+  CompilerInstance &CI = getCompilerInstance();
+  CI.getDiagnostics().getClient()->BeginSourceFile(
+                                             CI.getASTContext().getLangOpts());
+  CI.getDiagnostics().SetArgToStringFn(&FormatASTNodeDiagnosticArgument,
+                                       &CI.getASTContext());
+  IntrusiveRefCntPtr<DiagnosticIDs>
+      DiagIDs(CI.getDiagnostics().getDiagnosticIDs());
+  auto SharedState = std::make_shared<ASTImporterSharedState>(
+      *CI.getASTContext().getTranslationUnitDecl());
+  for (unsigned I = 0, N = ASTFiles.size(); I != N; ++I) {
+    IntrusiveRefCntPtr<DiagnosticsEngine>
+        Diags(new DiagnosticsEngine(DiagIDs, &CI.getDiagnosticOpts(),
+                                    new ForwardingDiagnosticConsumer(
+                                          *CI.getDiagnostics().getClient()),
+                                    /*ShouldOwnClient=*/true));
+    std::unique_ptr<ASTUnit> Unit = ASTUnit::LoadFromASTFile(
+        ASTFiles[I], CI.getPCHContainerReader(), ASTUnit::LoadEverything, Diags,
+        CI.getFileSystemOpts(), false);
+
+    if (!Unit)
+      continue;
+
+    ASTImporter Importer(CI.getASTContext(), CI.getFileManager(),
+                         Unit->getASTContext(), Unit->getFileManager(),
+                         /*MinimalImport=*/false, SharedState);
+
+    TranslationUnitDecl *TU = Unit->getASTContext().getTranslationUnitDecl();
+    for (auto *D : TU->decls()) {
+      // Don't re-import __va_list_tag, __builtin_va_list.
+      if (const auto *ND = dyn_cast<NamedDecl>(D))
+        if (IdentifierInfo *II = ND->getIdentifier())
+          if (II->isStr("__va_list_tag") || II->isStr("__builtin_va_list"))
+            continue;
+
+      llvm::Expected<Decl *> ToDOrError = Importer.Import(D);
+
+      if (ToDOrError) {
+        DeclGroupRef DGR(*ToDOrError);
+        CI.getASTConsumer().HandleTopLevelDecl(DGR);
+      } else {
+        llvm::consumeError(ToDOrError.takeError());
+      }
+    }
+  }
+
+  AdaptedAction->ExecuteAction();
+  CI.getDiagnostics().getClient()->EndSourceFile();
+}
+
+void ASTMergeAction::EndSourceFileAction() {
+  return AdaptedAction->EndSourceFileAction();
+}
+
+ASTMergeAction::ASTMergeAction(std::unique_ptr<FrontendAction> adaptedAction,
+                               ArrayRef<std::string> ASTFiles)
+: AdaptedAction(std::move(adaptedAction)), ASTFiles(ASTFiles.begin(), ASTFiles.end()) {
+  assert(AdaptedAction && "ASTMergeAction needs an action to adapt");
+}
+
+ASTMergeAction::~ASTMergeAction() {
+}
+
+bool ASTMergeAction::usesPreprocessorOnly() const {
+  return AdaptedAction->usesPreprocessorOnly();
+}
+
+TranslationUnitKind ASTMergeAction::getTranslationUnitKind() {
+  return AdaptedAction->getTranslationUnitKind();
+}
+
+bool ASTMergeAction::hasPCHSupport() const {
+  return AdaptedAction->hasPCHSupport();
+}
+
+bool ASTMergeAction::hasASTFileSupport() const {
+  return AdaptedAction->hasASTFileSupport();
+}
+
+bool ASTMergeAction::hasCodeCompletionSupport() const {
+  return AdaptedAction->hasCodeCompletionSupport();
+}