coff_reader.cpp

/**
 * Copyright (C) 2019 Patrick Mours. All rights reserved.
 * License: https://github.com/crosire/blink#license
 */

#include "blink.hpp"
#include "coff_reader.hpp"

scoped_handle open_coff_file(const std::filesystem::path &path, COFF_HEADER &header)
{
	scoped_handle file = CreateFileW(path.native().c_str(), GENERIC_READ, FILE_SHARE_READ, nullptr, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, nullptr);

	if (GetLastError() == ERROR_SHARING_VIOLATION)
	{
		// Try a couple more times in case the file was still locked by the compiler for writing
		for (int i = 0; i < 10 && file == INVALID_HANDLE_VALUE; i++)
		{
			Sleep(100);
			file = CreateFileW(path.native().c_str(), GENERIC_READ, FILE_SHARE_READ, nullptr, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, nullptr);
		}
	}

	if (file == INVALID_HANDLE_VALUE)
	{
		print("Failed to open " + path.string() + " (error code " + std::to_string(GetLastError()) + ").");
		return INVALID_HANDLE_VALUE;
	}

	// Read COFF header from input file and check that it is of a valid format
	if (DWORD read; !ReadFile(file, &header, sizeof(header), &read, nullptr))
	{
		print("Failed to read COFF header from " + path.string() + " (error code " + std::to_string(GetLastError()) + ").");
		return INVALID_HANDLE_VALUE;
	}

	// Need to adjust file position if this is not an extended COFF, since the normal header is smaller
	if (!header.is_extended())
		SetFilePointer(file, sizeof(header.obj), nullptr, FILE_BEGIN);

	return std::move(file);
}