glsl_preprocess.cc

Go to the documentation of this file.

/* SPDX-FileCopyrightText: 2024 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */

 
#include <fstream>
#include <iostream>
#include <regex>
#include <string>
 
#include "glsl_preprocess.hh"
 
int main(int argc, char **argv)
{
  if (argc != 4) {
    std::cerr << "Usage: glsl_preprocess <data_file_from> <data_file_to> <metadata_file_to>"
              << std::endl;
    exit(1);
  }
 
  const char *input_file_name = argv[1];
  const char *output_file_name = argv[2];
  const char *metadata_file_name = argv[3];
 
  /* Open the input file for reading */
  std::ifstream input_file(input_file_name);
  if (!input_file) {
    std::cerr << "Error: Could not open input file " << input_file_name << std::endl;
    exit(1);
  }
 
  /* Open the output file for writing */
  std::ofstream output_file(output_file_name, std::ofstream::out | std::ofstream::binary);
  if (!output_file) {
    std::cerr << "Error: Could not open output file " << output_file_name << std::endl;
    input_file.close();
    exit(1);
  }
 
  /* Open the output file for writing */
  std::ofstream metadata_file(metadata_file_name, std::ofstream::out | std::ofstream::binary);
  if (!output_file) {
    std::cerr << "Error: Could not open output file " << metadata_file_name << std::endl;
    input_file.close();
    exit(1);
  }
 
  std::stringstream buffer;
  buffer << input_file.rdbuf();
 
  int error = 0;
 
  auto count_lines = [](const std::string &str) {
    size_t lines = 0;
    for (char c : str) {
      if (c == '\n') {
        lines++;
      }
    }
    return lines;
  };
 
  auto get_line = [&](size_t line) {
    std::string src = buffer.str();
    size_t start = 0, end;
    for (; line > 1; line--) {
      start = src.find('\n', start + 1);
    }
    end = src.find('\n', start + 1);
    return src.substr(start + 1, end - (start + 1));
  };
 
  auto report_error = [&](const std::smatch &match, const char *err_msg) {
    size_t remaining_lines = count_lines(match.suffix());
    size_t total_lines = count_lines(buffer.str());
 
    size_t err_line = 1 + total_lines - remaining_lines;
    size_t err_char = (match.prefix().str().size() - 1) - match.prefix().str().rfind('\n');
 
    std::cerr << input_file_name;
    std::cerr << ':' << std::to_string(err_line) << ':' << std::to_string(err_char);
    std::cerr << ": error: " << err_msg << std::endl;
    std::cerr << get_line(err_line) << std::endl;
    std::cerr << std::string(err_char, ' ') << '^' << std::endl;
 
    error++;
  };
  std::string filename(output_file_name);
  const bool is_info = filename.find("info.hh") != std::string::npos;
  const bool is_glsl = filename.find(".glsl") != std::string::npos;
  const bool is_shared = filename.find("shared.h") != std::string::npos;
  const bool is_library = is_glsl &&
                          (filename.find("gpu_shader_material_") != std::string::npos ||
                           filename.find("gpu_shader_common_") != std::string::npos ||
                           filename.find("gpu_shader_compositor_") != std::string::npos);
 
  if (is_info) {
    std::cerr << "File " << output_file_name
              << " is a create info file and should not be processed as glsl" << std::endl;
    return 1;
  }
 
  using Preprocessor = blender::gpu::shader::Preprocessor;
  Preprocessor processor;
 
  Preprocessor::SourceLanguage language = Preprocessor::language_from_filename(filename);
 
  if (language == Preprocessor::SourceLanguage::GLSL) {
    /* All build-time GLSL files should be considered blender-GLSL. */
    language = Preprocessor::SourceLanguage::BLENDER_GLSL;
  }
 
  blender::gpu::shader::metadata::Source metadata;
  output_file << processor.process(
      language, buffer.str(), input_file_name, is_library, is_shared, report_error, metadata);
 
  /* TODO(fclem): Don't use regex for that. */
  std::string metadata_function_name = "metadata_" +
                                       std::regex_replace(
                                           filename, std::regex(R"((?:.*)\/(.*))"), "$1");
  std::replace(metadata_function_name.begin(), metadata_function_name.end(), '.', '_');
 
  metadata_file << metadata.serialize(metadata_function_name);
 
  input_file.close();
  output_file.close();
  metadata_file.close();
 
  return error;
}