Dump preprocessed file in verbose mode

include/cppast/libclang_parser.hpp

@@ -23,6 +23,8 @@ namespace cppast
             static int clang_version(const libclang_compile_config& config);
 
             static const std::vector<std::string>& flags(const libclang_compile_config& config);
+
+            static bool write_preprocessed(const libclang_compile_config& config);
         };
 
         void for_each_file(const libclang_compilation_database& database, void* user_data,
@@ -34,9 +36,7 @@ namespace cppast
     {
     public:
         /// \effects Creates it with a message.
-        libclang_error(std::string msg) : std::runtime_error(std::move(msg))
-        {
-        }
+        libclang_error(std::string msg) : std::runtime_error(std::move(msg)) {}
     };
 
     /// A compilation database.
@@ -121,6 +121,13 @@ namespace cppast
             clang_version_ = major * 10000 + minor * 100 + patch;
         }
 
+        /// \effects Sets whether or not the preprocessed file will be written out.
+        /// Default value is `false`.
+        void write_preprocessed(bool b) noexcept
+        {
+            write_preprocessed_ = b;
+        }
+
     private:
         void do_set_flags(cpp_standard standard, compile_flags flags) override;
 
@@ -137,6 +144,7 @@ namespace cppast
 
         std::string clang_binary_;
         int         clang_version_;
+        bool        write_preprocessed_;
 
         friend detail::libclang_compile_config_access;
     };

src/libclang/libclang_parser.cpp

@@ -5,6 +5,7 @@
 #include <cppast/libclang_parser.hpp>
 
 #include <cstring>
+#include <fstream>
 #include <vector>
 
 #include <clang-c/CXCompilationDatabase.h>
@@ -35,6 +36,12 @@ const std::vector<std::string>& detail::libclang_compile_config_access::flags(
     return config.get_flags();
 }
 
+bool detail::libclang_compile_config_access::write_preprocessed(
+    const libclang_compile_config& config)
+{
+    return config.write_preprocessed_;
+}
+
 libclang_compilation_database::libclang_compilation_database(const std::string& build_directory)
 {
     static_assert(std::is_same<database, CXCompilationDatabase>::value, "forgot to update type");
@@ -74,7 +81,7 @@ namespace
     }
 }
 
-libclang_compile_config::libclang_compile_config() : compile_config({})
+libclang_compile_config::libclang_compile_config() : compile_config({}), write_preprocessed_(false)
 {
     // set given clang binary
     auto ptr   = CPPAST_CLANG_VERSION_STRING;
@@ -446,8 +453,15 @@ std::unique_ptr<cpp_file> libclang_parser::do_parse(const cpp_entity_index& idx,
                  "config has mismatched type");
     auto& config = static_cast<const libclang_compile_config&>(c);
 
-    // preprocess + parse
+    // preprocess
     auto preprocessed = detail::preprocess(config, path.c_str(), logger());
+    if (detail::libclang_compile_config_access::write_preprocessed(config))
+    {
+        std::ofstream file(path + ".pp");
+        file << preprocessed.source;
+    }
+
+    // parse
     auto tu   = get_cxunit(logger(), pimpl_->index, config, path.c_str(), preprocessed.source);
     auto file = clang_getFile(tu.get(), path.c_str());
 

tool/main.cpp

@@ -87,12 +87,8 @@ void print_entity(std::ostream& out, const cppast::cpp_entity& e)
             }
 
             // no need to handle indentation, as only a single line is used
-            void do_indent() override
-            {
-            }
-            void do_unindent() override
-            {
-            }
+            void do_indent() override {}
+            void do_unindent() override {}
 
             // called when a generic token sequence should be generated
             // there are specialized callbacks for various token kinds,
@@ -249,6 +245,9 @@ int main(int argc, char* argv[]) try
                     cppast::libclang_compile_config(database, options["file"].as<std::string>());
         }
 
+        if (options.count("verbose"))
+            config.write_preprocessed(true);
+
         if (options.count("include_directory"))
             for (auto& include : options["include_directory"].as<std::vector<std::string>>())
                 config.add_include_dir(include);