[WIP] Run the ROMFS through a CPP with the boardconfig

Tools/px_romfs_preprocess.py

@@ -0,0 +1,188 @@
+#!/usr/bin/env python3
+"""
+Preprocesses ROMFS files with C preprocessor to enable KConfig support.
+
+This script processes all rc* files in the ROMFS directory through the C preprocessor,
+allowing use of #ifdef, #ifndef, #if, #else, #endif directives with KConfig definitions.
+"""
+
+import argparse
+import os
+import subprocess
+import sys
+import tempfile
+from pathlib import Path
+
+
+def preprocess_file(file_path, kconfig_header, cpp_command):
+    """
+    Preprocess a single file through the C preprocessor.
+
+    Uses % as the preprocessor directive symbol (instead of #) to avoid conflicts
+    with shell comments. Converts %ifdef, %ifndef, %if, %else, %endif to
+    #ifdef, #ifndef, #if, #else, #endif before preprocessing.
+
+    Args:
+        file_path: Path to the file to preprocess
+        kconfig_header: Path to the px4_boardconfig.h header
+        cpp_command: C preprocessor command (usually the C compiler)
+    """
+    # Read original file
+    with open(file_path, 'r') as f:
+        original_content = f.read()
+
+    # Process the file line by line:
+    # 1. Remove shell comment lines (to avoid conflicts with CPP)
+    # 2. Convert % preprocessor directives to # directives
+    lines = original_content.split('\n')
+    converted_lines = []
+
+    for line in lines:
+        stripped = line.lstrip()
+
+        # Check if line starts with % followed by a preprocessor keyword
+        if stripped.startswith('%ifdef ') or stripped.startswith('%ifdef\t'):
+            # Preserve leading whitespace, convert %ifdef to #ifdef
+            converted_lines.append(line.replace('%ifdef', '#ifdef', 1))
+        elif stripped.startswith('%ifndef ') or stripped.startswith('%ifndef\t'):
+            converted_lines.append(line.replace('%ifndef', '#ifndef', 1))
+        elif stripped.startswith('%if '):
+            converted_lines.append(line.replace('%if', '#if', 1))
+        elif stripped.startswith('%elif '):
+            converted_lines.append(line.replace('%elif', '#elif', 1))
+        elif stripped.startswith('%else'):
+            converted_lines.append(line.replace('%else', '#else', 1))
+        elif stripped.startswith('%endif'):
+            converted_lines.append(line.replace('%endif', '#endif', 1))
+        elif stripped.startswith('#') and not stripped.startswith('#!'):
+            # Remove shell comment lines (but keep shebang)
+            # This prevents "# if ..." comments from being interpreted as "#if" by CPP
+            continue
+        else:
+            converted_lines.append(line)
+    converted_content = '\n'.join(converted_lines)
+
+    # Create temporary file with include directive and converted content
+    with tempfile.NamedTemporaryFile(mode='w', suffix='.in', delete=False) as tmp:
+        tmp.write(f'#include "{kconfig_header}"\n')
+        tmp.write(converted_content)
+        tmp_path = tmp.name
+
+    try:
+        # Run C preprocessor
+        # -P: don't generate #line directives
+        # -E: preprocess only
+        # -undef: don't predefine any non-standard macros
+        # -nostdinc: don't search standard include directories
+        # -x assembler-with-cpp: treat input as assembly (allows # comments to pass through)
+        result = subprocess.run(
+            [cpp_command, '-P', '-E', '-undef', '-nostdinc', '-x', 'assembler-with-cpp', tmp_path],
+            capture_output=True,
+            text=True,
+            check=True
+        )
+
+        preprocessed = result.stdout
+
+        # Clean up the output:
+        # 1. Remove empty lines at the beginning
+        # 2. Remove lines that are just whitespace
+        lines = preprocessed.split('\n')
+        cleaned_lines = []
+        started = False
+
+        for line in lines:
+            # Skip empty lines at the beginning
+            if not started and not line.strip():
+                continue
+            started = True
+            cleaned_lines.append(line)
+
+        # Remove trailing empty lines
+        while cleaned_lines and not cleaned_lines[-1].strip():
+            cleaned_lines.pop()
+
+        # Write preprocessed content back
+        with open(file_path, 'w') as f:
+            f.write('\n'.join(cleaned_lines))
+            if cleaned_lines:  # Add final newline if file is not empty
+                f.write('\n')
+
+        return True
+
+    except subprocess.CalledProcessError as e:
+        print(f"Error preprocessing {file_path}: {e}")
+        print(f"stderr: {e.stderr}")
+        return False
+    finally:
+        # Clean up temporary file
+        try:
+            os.unlink(tmp_path)
+        except:
+            pass
+
+
+def main():
+    parser = argparse.ArgumentParser(description='Preprocess ROMFS files with KConfig definitions')
+    parser.add_argument('--romfs-dir', required=True, help='ROMFS root directory')
+    parser.add_argument('--kconfig-header', required=True, help='Path to px4_boardconfig.h')
+    parser.add_argument('--cpp', required=True, help='C preprocessor command')
+    parser.add_argument('--pattern', default='rc*', help='File pattern to preprocess (default: rc*)')
+
+    args = parser.parse_args()
+
+    # Verify inputs
+    romfs_dir = Path(args.romfs_dir)
+    kconfig_header = Path(args.kconfig_header)
+
+    if not romfs_dir.exists():
+        print(f"Error: ROMFS directory not found: {romfs_dir}")
+        return 1
+
+    if not kconfig_header.exists():
+        print(f"Error: KConfig header not found: {kconfig_header}")
+        return 1
+
+    # Find all files to preprocess in init.d directory
+    init_d_dir = romfs_dir / 'init.d'
+    if not init_d_dir.exists():
+        print(f"Warning: init.d directory not found in {romfs_dir}")
+        return 0
+
+    # Find all rc* files (shell scripts)
+    files_to_process = []
+    for pattern in ['rc*', 'rcS']:
+        files_to_process.extend(init_d_dir.glob(pattern))
+
+    # Also check subdirectories like airframes
+    for subdir in init_d_dir.iterdir():
+        if subdir.is_dir():
+            for pattern in ['rc*']:
+                files_to_process.extend(subdir.glob(pattern))
+
+    # Remove duplicates and filter only files
+    files_to_process = list(set([f for f in files_to_process if f.is_file()]))
+
+    if not files_to_process:
+        print(f"Warning: No files matching pattern '{args.pattern}' found in {init_d_dir}")
+        return 0
+
+    print(f"Preprocessing {len(files_to_process)} ROMFS files with KConfig definitions...")
+
+    # Process each file
+    success_count = 0
+    for file_path in sorted(files_to_process):
+        rel_path = file_path.relative_to(romfs_dir)
+        print(f"  Processing: {rel_path}")
+        if preprocess_file(file_path, kconfig_header.absolute(), args.cpp):
+            success_count += 1
+        else:
+            print(f"  Warning: Failed to preprocess {rel_path}")
+
+    print(f"Successfully preprocessed {success_count}/{len(files_to_process)} files")
+
+    return 0 if success_count == len(files_to_process) else 1
+
+
+if __name__ == '__main__':
+    sys.exit(main())