blob: bce4b7d28485f9036cafbe2120bc76c9cd4fa8ed [file] [log] [blame]
// Protocol Buffers - Google's data interchange format
// Copyright 2023 Google LLC. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd
#include "google/protobuf/descriptor.pb.h"
#include "absl/strings/str_replace.h"
#include "absl/strings/string_view.h"
#include "absl/strings/substitute.h"
#include "google/protobuf/compiler/code_generator.h"
#include "google/protobuf/compiler/plugin.h"
#include "google/protobuf/descriptor.h"
#include "google/protobuf/io/printer.h"
namespace protoc = ::google::protobuf::compiler;
namespace protobuf = ::google::protobuf;
class LuaGenerator : public protoc::CodeGenerator {
bool Generate(const protobuf::FileDescriptor* file,
const std::string& parameter, protoc::GeneratorContext* context,
std::string* error) const override;
};
static std::string StripExtension(absl::string_view fname) {
size_t lastdot = fname.find_last_of('.');
if (lastdot == std::string::npos) {
return std::string(fname);
}
return std::string(fname.substr(0, lastdot));
}
static std::string Filename(const protobuf::FileDescriptor* file) {
return StripExtension(file->name()) + "_pb.lua";
}
static std::string ModuleName(const protobuf::FileDescriptor* file) {
std::string ret = StripExtension(file->name()) + "_pb";
return absl::StrReplaceAll(ret, {{"/", "."}});
}
static void PrintHexDigit(char digit, protobuf::io::Printer* printer) {
char text;
if (digit < 10) {
text = '0' + digit;
} else {
text = 'A' + (digit - 10);
}
printer->WriteRaw(&text, 1);
}
static void PrintString(int max_cols, absl::string_view* str,
protobuf::io::Printer* printer) {
printer->Print("\'");
while (max_cols > 0 && !str->empty()) {
char ch = (*str)[0];
if (ch == '\\') {
printer->PrintRaw("\\\\");
max_cols--;
} else if (ch == '\'') {
printer->PrintRaw("\\'");
max_cols--;
} else if (isprint(ch)) {
printer->WriteRaw(&ch, 1);
max_cols--;
} else {
unsigned char byte = ch;
printer->PrintRaw("\\x");
PrintHexDigit(byte >> 4, printer);
PrintHexDigit(byte & 15, printer);
max_cols -= 4;
}
str->remove_prefix(1);
}
printer->Print("\'");
}
bool LuaGenerator::Generate(const protobuf::FileDescriptor* file,
const std::string& /* parameter */,
protoc::GeneratorContext* context,
std::string* /* error */) const {
std::string filename = Filename(file);
protobuf::io::ZeroCopyOutputStream* out = context->Open(filename);
protobuf::io::Printer printer(out, '$');
for (int i = 0; i < file->dependency_count(); i++) {
const protobuf::FileDescriptor* dep = file->dependency(i);
printer.Print("require('$name$')\n", "name", ModuleName(dep));
}
printer.Print("local upb = require('upb')\n");
protobuf::FileDescriptorProto file_proto;
file->CopyTo(&file_proto);
std::string file_data;
file_proto.SerializeToString(&file_data);
printer.Print("local descriptor = table.concat({\n");
absl::string_view data(file_data);
while (!data.empty()) {
printer.Print(" ");
PrintString(72, &data, &printer);
printer.Print(",\n");
}
printer.Print("})\n");
printer.Print("return upb._generated_module(descriptor)\n");
return true;
}
int main(int argc, char** argv) {
LuaGenerator generator;
return google::protobuf::compiler::PluginMain(argc, argv, &generator);
}