basic setting of ParsedAST.

include/AST/Diagnostic.h

@@ -0,0 +1,11 @@
+#pragma once
+
+#include <clang/AST/RecursiveASTVisitor.h>
+#include <clang/Basic/Diagnostic.h>
+#include <clang/Frontend/CompilerInstance.h>
+#include <clang/Frontend/FrontendActions.h>
+#include <clang/Frontend/TextDiagnosticPrinter.h>
+#include <clang/Sema/Sema.h>
+#include <clang/Tooling/CompilationDatabase.h>
+#include <clang/Tooling/Syntax/Tokens.h>
+#include <clang/Lex/PPCallbacks.h>

include/AST/ParsedAST.h

@@ -0,0 +1,21 @@
+#pragma once
+
+#include "Preamble.h"
+
+namespace clice {
+
+struct ParsedAST {
+    std::unique_ptr<clang::FrontendAction> action;
+    std::unique_ptr<clang::CompilerInstance> instance;
+
+    static std::unique_ptr<ParsedAST>
+        build(llvm::StringRef filename, llvm::StringRef content, std::vector<const char*>& args, Preamble* preamble);
+
+    auto& ASTContext() const { return instance->getASTContext(); }
+
+    auto& SourceManager() const { return instance->getSourceManager(); }
+
+    auto TranslationUnitDecl() const { return ASTContext().getTranslationUnitDecl(); }
+};
+
+}  // namespace clice

include/AST/Preamble.h

@@ -0,0 +1,17 @@
+#pragma once
+
+#include "Diagnostic.h"
+
+namespace clice {
+
+/// Represents the preamble of a translation unit.
+/// We build preamble for the translation after first edit.
+/// The preamble is used to speed up the reparse of the translation unit.
+struct Preamble {
+    clang::PrecompiledPreamble data;
+
+    static std::unique_ptr<Preamble>
+        build(llvm::StringRef filename, llvm::StringRef content, std::vector<const char*>& args);
+};
+
+}  // namespace clice