output: emit include statement for header

src/output.cpp

@@ -27,6 +27,7 @@
 #include "output.hpp"
 
 #include <cerrno>
+#include <cstring>
 #include <system_error>
 
 
@@ -36,7 +37,8 @@ output_t::output_t(const generator_t *generator0, const char *header, const char
 	: prefix_str("parse_"),
 	  token_prefix_str("TOK_"),
 	  stack_size(100),
-	  generator(generator0) {
+	  generator(generator0),
+	  header_filename(header) {
 	header_file = std::fopen(header, "w");
 	if (!header_file)
 		throw std::system_error(errno, std::generic_category(), "unable to open header output file for writing");
@@ -249,7 +251,22 @@ void output_t::emit_states() {
 		emit_state(i);
 }
 
+void output_t::emit_header_include() {
+#ifdef _WIN32
+	const char sep = '\\';
+#else
+	const char sep = '/';
+#endif
+
+	const char *slash = std::strrchr(header_filename.c_str(), sep);
+	const char *basename = slash ? slash+1 : header_filename.c_str();
+
+	std::fprintf(source_file, "#include \"%s\"\n\n\n", basename);
+}
+
 void output_t::emit_source() {
+	emit_header_include();
+
 	std::fprintf(source_file, "typedef union %ssymbol_value {\n", prefix());
 	std::fprintf(source_file, "\t%stoken_value_t token;\n", prefix());
 

src/output.hpp

@@ -41,6 +41,8 @@ private:
 
 	const generator_t *generator;
 
+	std::string header_filename;
+
 	std::FILE *header_file;
 	std::FILE *source_file;
 
@@ -67,6 +69,7 @@ private:
 	void emit_state_reduce(const item_t &item, int rule_id);
 	void emit_state(unsigned i);
 	void emit_states();
+	void emit_header_include();
 	void emit_source();
 
 public: