BlitzNext/Linker/lib/dlltoexe.cpp

#include "dlltoexe.hpp"
#include <fstream>

#include <Windows.h>

#pragma pack(push, 1)
struct Head {
	short machine, num_sects;
	int   timedata, sym_table, num_syms;
	short opt_size, chars;
};

struct Opt1 {
	short magic;
	char  major, minor;
	int   code_size, data_size, udata_size;
	int   entry, code_base, data_base;
};

struct Sect {
	char  name[8];
	int   virt_size, virt_addr; //in mem
	int   data_size, data_addr; //on disk
	int   relocs, lines;        //file ptrs
	short num_relocs, num_lines;
	int   chars;
};
#pragma pack(pop)

bool dllToExe(const char* exe_file, const char* dll_file, const char* entry_func)
{
	//find proc address of bbWinMain
	HMODULE hmod = LoadLibrary(dll_file);
	if (!hmod)
		return false;
	int proc  = (int)GetProcAddress(hmod, entry_func);
	int entry = proc - (int)hmod;
	FreeLibrary(hmod);
	if (!proc)
		return false;

	//Convert dll to exe
	std::fstream in(dll_file, std::ios_base::binary | std::ios_base::in);
	if (!in.is_open())
		return false;
	std::fstream out(exe_file, std::ios::binary | std::ios_base::out | std::ios_base::trunc);
	if (!out.is_open())
		return false;

	int offs;
	in.seekg(0x3c);
	in.read((char*)&offs, 4);

	//copy first bit...
	in.seekg(0);
	for (int k = 0; k < offs + 4; ++k)
		out.put(in.get());

	//reader file header
	Head head = {0};
	in.read((char*)&head, sizeof(head));
	//change DLL to EXE
	head.chars = 0x10e;
	out.write((char*)&head, sizeof(head));

	//read opts 1
	Opt1 opt1 = {0};
	in.read((char*)&opt1, sizeof(opt1));
	opt1.entry = entry;
	out.write((char*)&opt1, sizeof(opt1));

	//copy rest of file...
	while (!in.eof()) {
		out.put(in.get());
	}

	out.close();
	in.close();

	return true;
}