Track included files in PATH-agnostic way. (#4329)

* Track included files in PATH-agnostic way.

Use full paths as keys in the map of included files. Store logical
include path as a value, in order to put it to the generated file.

* Fix tests by accepting null |include_filename|.

* Fix self-includes code generators.

include/flatbuffers/idl.h

@@ -610,7 +610,7 @@ private:
   std::string file_identifier_;
   std::string file_extension_;
 
-  std::map<std::string, bool> included_files_;
+  std::map<std::string, std::string> included_files_;
   std::map<std::string, std::set<std::string>> files_included_per_file_;
   std::vector<std::string> native_included_files_;
 

src/idl_gen_cpp.cpp

@@ -72,14 +72,15 @@ class CppGenerator : public BaseGenerator {
     }
     for (auto it = parser_.included_files_.begin();
          it != parser_.included_files_.end(); ++it) {
-      auto noext = flatbuffers::StripExtension(it->first);
+      if (it->second.empty())
+        continue;
+      auto noext = flatbuffers::StripExtension(it->second);
       auto basename = flatbuffers::StripPath(noext);
-      if (basename != file_name_) {
-        code_ += "#include \"" + parser_.opts.include_prefix +
-                 (parser_.opts.keep_include_path ? noext : basename) +
-                 "_generated.h\"";
-        num_includes++;
-      }
+
+      code_ += "#include \"" + parser_.opts.include_prefix +
+               (parser_.opts.keep_include_path ? noext : basename) +
+               "_generated.h\"";
+      num_includes++;
     }
     if (num_includes) code_ += "";
   }

src/idl_gen_fbs.cpp

@@ -72,12 +72,12 @@ std::string GenerateFBS(const Parser &parser, const std::string &file_name) {
     int num_includes = 0;
     for (auto it = parser.included_files_.begin();
          it != parser.included_files_.end(); ++it) {
+      if (it->second.empty())
+        continue;
       auto basename = flatbuffers::StripPath(
-                        flatbuffers::StripExtension(it->first));
-      if (basename != file_name) {
-        schema += "include \"" + basename + ".fbs\";\n";
-        num_includes++;
-      }
+                        flatbuffers::StripExtension(it->second));
+      schema += "include \"" + basename + ".fbs\";\n";
+      num_includes++;
     }
     if (num_includes) schema += "\n";
     #endif

src/idl_parser.cpp

@@ -1917,8 +1917,7 @@ CheckedError Parser::SkipJsonString() {
 
 bool Parser::Parse(const char *source, const char **include_paths,
                    const char *source_filename) {
-  return !DoParse(source, include_paths, source_filename,
-                  source_filename).Check();
+  return !DoParse(source, include_paths, source_filename, nullptr).Check();
 }
 
 CheckedError Parser::DoParse(const char *source, const char **include_paths,
@@ -1926,8 +1925,8 @@ CheckedError Parser::DoParse(const char *source, const char **include_paths,
                              const char *include_filename) {
   file_being_parsed_ = source_filename ? source_filename : "";
   if (source_filename &&
-      included_files_.find(include_filename) == included_files_.end()) {
-    included_files_[include_filename] = true;
+      included_files_.find(source_filename) == included_files_.end()) {
+    included_files_[source_filename] = include_filename ? include_filename : "";
     files_included_per_file_[source_filename] = std::set<std::string>();
   }
   if (!include_paths) {
@@ -1976,7 +1975,7 @@ CheckedError Parser::DoParse(const char *source, const char **include_paths,
         return Error("unable to locate include file: " + name);
       if (source_filename)
         files_included_per_file_[source_filename].insert(filepath);
-      if (included_files_.find(name) == included_files_.end()) {
+      if (included_files_.find(filepath) == included_files_.end()) {
         // We found an include file that we have not parsed yet.
         // Load it and parse it.
         std::string contents;