path: root/main.c

#define VERSION "0.0"

#if __GNUC__
#define UNUSED __attribute__((unused))
#else
#define UNUSED
#endif

#if __unix__
	#define _POSIX_C_SOURCE 200809L
	#include <sys/stat.h>
	#include <sys/wait.h>
	#include <sys/mman.h>
	#include <unistd.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <fcntl.h>
	#include <limits.h>
	#include <ctype.h>
	#include <assert.h>
	#define C_PREPROCESSOR_DEFAULT "/usr/bin/tcc"

	static int file_is_readable(const char *name) {
		return access(name, R_OK) == 0;
	}

	#if __GNUC__
		#pragma GCC diagnostic push
		#pragma GCC diagnostic error "-Wpadded"
	#endif
	typedef struct {
		unsigned magic;
		unsigned char class;
		unsigned char endianness;
		unsigned char version;
		unsigned char abi;
		unsigned char abi_version;
		char _pad1[7];
		unsigned short type;
		unsigned short architecture;
		unsigned version2;
		size_t entry;
		size_t phoff;
		size_t shoff;
		unsigned flags;
		unsigned short ehsize;
		unsigned short phentsize;
		unsigned short phnum;
		unsigned short shentsize;
		unsigned short shnum;
		unsigned short shstrndx;
	} ELFHeader;

	typedef struct {
		unsigned name;
		unsigned type;
		size_t flags;
		size_t addr;
		size_t offset;
		size_t size;
		unsigned link;
		unsigned info;
		size_t addralign;
		size_t entsize;
	} ELFSectionHeader;

	#if LONG_MAX == 0x7fffffff
	/* 32-bit struct */
	typedef struct {
		unsigned name;
		size_t value;
		size_t size;
		unsigned char info;
		unsigned char other;
		unsigned short shndx;
	} ELFSym;
	#else
	/* 64-bit struct */
	typedef struct {
		unsigned name;
		unsigned char info;
		unsigned char other;
		unsigned short shndx;
		size_t value;
		size_t size;
	} ELFSym;
	#endif

	#if __GNUC__
		#pragma GCC diagnostic pop
	#endif

#elif _WIN32
	#define C_PREPROCESSOR_DEFAULT "cl"
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <limits.h>
	#include <ctype.h>
	#include <assert.h>
	#error "@TODO"
#else
	#error "Unsupported operating system."
#endif


#define VERSION_TEXT "dlsub version " VERSION "\n"



static void show_help_text_and_exit(const char *program_name) {
	printf(VERSION_TEXT
		"\n");
	printf(
		"Usage: %s -i <header file> -l <dynamic library file> ...\n",
		program_name);
	printf(
		"Options:\n"
		"\t-i <header file>         Add a header file to be processed.\n"
		"\t-I <include directory>   Add an include directory when preprocessing header files.\n"
		"\t-l <dynamic library>     Set the dynamic library file you want to replace.\n"
		"\t-o <output name>         Set the output file name.\n"
		"\t-C <argument>            Add an argument for the C preprocessor.\n"
	);
	printf(
		"\t--no-warn                Disable warnings if a function isn't found in a header file.\n"
		"\t--help                   Show this help text and exit.\n"
		"\t--version                Show version number and exit.\n"
		"Environment variables:\n"
		"\tC_PREPROCESSOR - Program to be used for C preprocessing (default: '" C_PREPROCESSOR_DEFAULT "')\n"
	);
	exit(0);
}

/* can `c' appear in a C identifier? */
static int is_ident(int c) {
	return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9') || c == '_';
}

static unsigned long str_hash(const char *str) {
    unsigned long hash = 5381;
	const unsigned char *p;

    for (p = (const unsigned char *)str; *p; ++p)
        hash = ((hash << 5) + hash) + *p;

    return hash;
}


typedef struct {
	unsigned char declared; /* have we found this in a header file */
	char symbol[1];
} SymbolHashEntry;

typedef struct {
	size_t n_entries;
	size_t n_present_entries;
	SymbolHashEntry **entries;
} SymbolHashTable;

static void symbol_hash_table_grow(SymbolHashTable *table) {
	size_t i, new_n_entries = 2*table->n_entries + 55;
	SymbolHashEntry **new_entries = calloc(new_n_entries, sizeof *new_entries);
	if (!new_entries) {
		fprintf(stderr, "Out of memory.\n");
		exit(2);
	}
	
	for (i = 0; i < table->n_entries; ++i) {
		SymbolHashEntry *entry = table->entries[i];
		unsigned long p;
		if (!entry) continue;
		p = str_hash(entry->symbol) % new_n_entries;
		while (new_entries[p]) {
			++p;
			if (p >= new_n_entries) p -= new_n_entries;
		}
		new_entries[p] = entry;
	}

	free(table->entries);
	table->entries = new_entries;
	table->n_entries = new_n_entries;
}

static void symbol_hash_table_insert(SymbolHashTable *table, const char *sym_name) {
	unsigned long p;
	SymbolHashEntry *entry;
	if (table->n_present_entries * 2 >= table->n_entries) {
		symbol_hash_table_grow(table);
	}

	p = str_hash(sym_name) % table->n_entries;
	while ((entry = table->entries[p])) {
		if (strcmp(entry->symbol, sym_name) == 0)
			return; /* already exists */

		++p;
		if (p >= table->n_entries) p -= table->n_entries;
	}
	entry = calloc(1, sizeof *entry + strlen(sym_name) + 1);
	if (!entry) {
		fprintf(stderr, "Out of memory.\n");
		exit(2);
	}
	strcpy(entry->symbol, sym_name);
	++table->n_present_entries;
	table->entries[p] = entry;
}

static SymbolHashEntry *symbol_hash_table_get(SymbolHashTable *table, const char *name) {
	unsigned long p = str_hash(name) % table->n_entries;
	SymbolHashEntry *entry;
	while ((entry = table->entries[p])) {
		if (strcmp(entry->symbol, name) == 0)
			return entry;
		++p;
		if (p >= table->n_entries) p -= table->n_entries;
	}
	return 0;
}

static void symbol_hash_table_free(SymbolHashTable *table) {
	size_t i;
	for (i = 0; i < table->n_entries; ++i)
		free(table->entries[i]);
	free(table->entries);
	memset(table, 0, sizeof *table);
}

int main(int argc, char **argv) {
	char *preprocessed_headers;
	size_t preprocessed_headers_len = 0;
	const char *preprocessor_program = C_PREPROCESSOR_DEFAULT;
	const char *output_name = NULL;
	const char *input_filename = NULL;
	int no_warn = 0;

	SymbolHashTable all_symbols = {0}; /* all symbols in all provided libraries */

	int i;

	{
		char *p = getenv("C_PREPROCESSOR");
		if (p)
			preprocessor_program = p;
	}
	
	{
		/* parse arguments */
		for (i = 1; i < argc; ++i) {
			if (argv[i][0] == '-') {
				switch (argv[i][1]) {
				case 'i':
					if (i < argc-1) {
						++i;
					} else {
						fprintf(stderr, "-i must be followed by a file name.\n");
						exit(-1);
					}
					break;
				case 'l':
					if (i < argc-1) {
						input_filename = argv[i+1];
						++i;
					} else {
						fprintf(stderr, "-l must be followed by a file name.\n");
						exit(-1);
					}
					break;
				case 'I':
					if (i < argc-1) {
						++i;
					} else {
						fprintf(stderr, "-I must be followed by a directory name.\n");
						exit(-1);
					}
					break;
				case 'C':
					if (i < argc-1) {
						++i;
					} else {
						fprintf(stderr, "-I must be followed by a directory name.\n");
						exit(-1);
					}
					break;
				case 'o':
					if (output_name) {
						fprintf(stderr, "-o specified twice.\n");
						exit(-1);
					} else if (i < argc-1) {
						output_name = argv[i+1];
						++i;
					} else {
						fprintf(stderr, "-o must be followed by a file name.\n");
						exit(-1);
					}
					break;
				case '-':
					if (strcmp(argv[i], "--help") == 0) {
						show_help_text_and_exit(argv[0]);
					} else if (strcmp(argv[i], "--version") == 0) {
						printf(VERSION_TEXT);
						exit(0);
					} else if (strcmp(argv[i], "--no-warn") == 0) {
						no_warn = 1;
					} else goto unrecognized;
					break;
				default:
				unrecognized:
					fprintf(stderr, "Unrecognized flag: '%s'.\n", argv[i]);
					break;
				}
			} else {
				fprintf(stderr, "Stray argument (#%d): '%s'.\n", i, argv[i]);
				exit(-1);
			}
		}
		if (!input_filename) {
			show_help_text_and_exit(argv[0]);
		}
	}

	if (!output_name) {
		output_name = "out";
	}


	if (!file_is_readable(input_filename)) {
		fprintf(stderr, "Can't open provided dynamic library file: '%s'.\n", input_filename);
		exit(1);
	}

	/* read library */
	{
		const char *libname = input_filename;
		FILE *fp = fopen(libname, "rb");

		if (!fp) {
			char prefix[128];
			sprintf(prefix, "Couldn't open %.100s.\n", libname);
			perror(prefix);
			exit(1);
		}

	#if __unix__	
		{
			ELFHeader elf_header = {0};
			int any_dynsym = 0;
			size_t dynstr_offset = 0;
			unsigned shidx;

			fread(&elf_header, sizeof elf_header, 1, fp);

			if (elf_header.magic != 0x464c457f || elf_header.type != 3) {
				fprintf(stderr, "%s is not an ELF dynamic library.\n", libname);
				exit(2);
			}
			if (elf_header.endianness != 1
				|| elf_header.shentsize < (sizeof(size_t) == 4 ? 0x28 : 0x40)
				|| elf_header.class * 4 != sizeof(size_t)
				|| elf_header.shoff > LONG_MAX) {
				fprintf(stderr, "%s has an unsupported or invalid ELF format.\n", libname);
				exit(2);
			}

			{
				ELFSectionHeader strtab_header = {0}, section_header = {0};

				fseek(fp, (long)elf_header.shoff + (long)elf_header.shentsize * elf_header.shstrndx, SEEK_SET);
				fread(&strtab_header, sizeof strtab_header, 1, fp);

				for (shidx = 0; shidx < elf_header.shnum; ++shidx) {
					char secname[32] = {0};
					fseek(fp, (long)(elf_header.shoff + shidx * elf_header.shentsize), SEEK_SET);
				
					fread(&section_header, sizeof section_header, 1, fp);
					fseek(fp, (long)strtab_header.offset + (long)section_header.name, SEEK_SET);
					fread(secname, 1, sizeof secname-1, fp);
					if (strcmp(secname, ".dynstr") == 0) {
						dynstr_offset = section_header.offset;
					}
				}
			}

			if (dynstr_offset == 0) {
				fprintf(stderr, "%s has no .dynstr section.\n", libname);
				exit(2);
			}

			
			{
				ELFSectionHeader section_header = {0};
				
				for (shidx = 0; shidx < elf_header.shnum; ++shidx) {
					fseek(fp, (long)(elf_header.shoff + shidx * elf_header.shentsize), SEEK_SET);
					fread(&section_header, sizeof section_header, 1, fp);
					if (section_header.type == 0xB /* SHT_DYNSYM */) {
						ELFSym sym = {0};
						size_t nsyms, sym_idx;
						char sym_name[256] = {0};

						any_dynsym = 1;
						
						if (section_header.entsize < sizeof(ELFSym) || section_header.offset > LONG_MAX) {
							fprintf(stderr, "%s has an unsupported or invalid ELF format.\n", libname);
							exit(2);
						}

						nsyms = section_header.size / section_header.entsize;
						
						for (sym_idx = 0; sym_idx < nsyms; ++sym_idx) {

							fseek(fp, (long)(section_header.offset + sym_idx * section_header.entsize), SEEK_SET);
							fread(&sym, sizeof sym, 1, fp);
							if (sym.other == 2 || sym.other == 6 /* check visibility */
								|| (sym.info & 0xf) != 2 /* check if is function */
								|| (sym.info >> 4) != 1 /* make sure "bind" is global */
								|| sym.value == 0 /* make sure this function is actually *from* this library */) {
								/* this symbol isn't a function exported by the dynamic library. it's something else */
							} else {
								fseek(fp, (long)(dynstr_offset + sym.name), SEEK_SET);
								fread(sym_name, 1, sizeof sym_name - 1, fp);
								/*printf("%02x %02x %08lx %08lx %s\n",sym.other,sym.info,sym.value,sym.size,sym_name);*/
								symbol_hash_table_insert(&all_symbols, sym_name);
							}
						}
					}
				}
			}
			
			if (!any_dynsym) {
				fprintf(stderr, "%s does not have a symbol table.\n", libname);
				exit(2);
			}
		}
	#else
		#error "@TODO"
	#endif
		
		fclose(fp);
	}

#if __unix__
	{
		int preprocessed_headers_fd = fileno(tmpfile());
		pid_t compiler_process;
		int pipefd[2];

		if (preprocessed_headers_fd == -1) {
			perror("Couldn't create temporary preprocessing output file");
			exit(2);
		}
		
		if (pipe(pipefd) == -1) {
			perror("Couldn't create pipe");
			exit(2);
		}

		compiler_process = fork();

		switch (compiler_process) {
		case -1:
			perror("Couldn't create compiler process");
			exit(2);
		case 0: {
		#define MAX_CC_ARGV 4000
			static char *cc_argv[MAX_CC_ARGV+1];
			int a = 0;
			/* child */
			close(pipefd[1]); /* don't need write end of pipe */
			if (dup2(pipefd[0], 0) == -1) {
				perror("Couldn't redirect pipe to C compiler's stdin");
				exit(2);
			}
			if (dup2(preprocessed_headers_fd, 1) == -1) {
				perror("Couldn't redirect C compiler's stdout to file");
				exit(2);
			}

			cc_argv[a++] = (char *)preprocessor_program;
			cc_argv[a++] = "-E";
			cc_argv[a++] = "-";
			for (i = 1; i < argc-1; ++i) {
				if (strcmp(argv[i], "-I") == 0) {
					if (a + 2 > MAX_CC_ARGV) {
						fprintf(stderr, "Too many compiler arguments.\n");
						exit(-1);
					}
					cc_argv[a++] = "-I";
					cc_argv[a++] = argv[i+1];
				} else if (strcmp(argv[i], "-C") == 0) {
					if (a + 1 > MAX_CC_ARGV) {
						fprintf(stderr, "Too many compiler arguments.\n");
						exit(-1);
					}
					cc_argv[a++] = argv[i+1];
				}
				if (argv[i][0] == '-' && argv[i][1] != '-') ++i;
			}
			cc_argv[a++] = NULL;
			if (execv(preprocessor_program, cc_argv) == -1) {
				perror("Couldn't start C compiler");
				exit(2);
			}
		} break;
		default:
			break;
		}

		/* parent */
		close(pipefd[0]); /* don't need read end of pipe */
		for (i = 1; i < argc-1; ++i) {
			if (strcmp(argv[i], "-i") == 0) {
				const char *header = argv[i+1];
				int fd = open(header, O_RDONLY);
				char buf[4096];
				ssize_t bytes_read;

				if (fd == -1) {
					/* check include directories */
					char path[520];
					int j;
					for (j = 1; j < argc-1; ++j) {
						if (strcmp(argv[j], "-I") == 0) {
							const char *dir = argv[j+1];
							sprintf(path, "%.256s/%.256s", dir, header);
							fd = open(path, O_RDONLY);
							if (fd != -1) break;
						}
						if (argv[j][0] == '-' && argv[j][1] != '-') ++j;
					}
				
					if (fd == -1) {
						char prefix[128];
						sprintf(prefix, "Couldn't open %.100s", header);
						perror(prefix);
						kill(SIGKILL, compiler_process);
						exit(2);
					}
				}
				
				while ((bytes_read = read(fd, buf, sizeof buf)) > 0) {
					write(pipefd[1], buf, (size_t)bytes_read);
				}

				if (bytes_read < 0) {
					char prefix[128];
					sprintf(prefix, "Error reading %.100s", header);
					perror(prefix);
					kill(SIGKILL, compiler_process);
					exit(2);
				}

				close(fd);
			}
			if (argv[i][0] == '-' && argv[i][1] != '-') ++i;
		}
	
		close(pipefd[1]);

		/* wait for compiler to finish */
		while (1) {
			int status = 0;
			wait(&status);
			if (WIFEXITED(status)) {
				int exit_status = WEXITSTATUS(status);
				if (exit_status == 0) {
					break;
				} else {
					fprintf(stderr, "C preprocessor failed with exit code %d\n", exit_status);
					exit(exit_status);
				}
			} else if (WIFSIGNALED(status)) {
				int sig = WTERMSIG(status);
				fprintf(stderr, "C preprocessor terminated with signal %s (#%d)\n", strsignal(sig), sig);
				exit(2);
			}
		}

		{
			struct stat statbuf = {0};
			fstat(preprocessed_headers_fd, &statbuf);
			preprocessed_headers_len = (size_t)statbuf.st_size;
			preprocessed_headers = mmap(NULL, preprocessed_headers_len, PROT_READ, MAP_PRIVATE,
				preprocessed_headers_fd, 0);
			if (preprocessed_headers == MAP_FAILED) {
				perror("Couldn't map preprocessed headers file into memory");
				exit(2);
			}
		}
		
	}
#else
	#error "@TODO"
#endif


	/* figure out functions! */


	{
		FILE *c_output;
		FILE *nasm_output; 
		size_t c = 0;
		const char *semicolon;
		

		{
			char filename[1024];
			
			sprintf(filename, "%.1000s.c", output_name);
			c_output = fopen(filename, "w");
			if (!c_output) {
				perror("Couldn't open C output file");
				exit(1);
			}
			
			sprintf(filename, "%.1000s.asm", output_name);
			nasm_output = fopen(filename, "w");
			if (!nasm_output) {
				perror("Couldn't open nasm output file");
				exit(1);
			}
		}

		for (i = 1; i < argc-1; ++i) {
			if (strcmp(argv[i], "-i") == 0) {
				fprintf(c_output, "#include <%s>\n", argv[i+1]);
			}
			if (argv[i][0] == '-' && argv[i][1] != '-') ++i;
		}

		fprintf(c_output, "#define DLSUB_REAL_DL_NAME \"%s\"\n", input_filename);

		fprintf(c_output,
			"static void dlsub_init(void);\n"
			"\n"
			"#if __unix__\n"
			"#include <dlfcn.h>\n"
			"#define DLSUB_GET_DLHANDLE(filename) dlopen(filename, RTLD_LAZY)\n"
			"#define DLSUB_GET_SYM(handle, name) ((void(*)(void))dlsym(handle, name))\n"
			"#define DLSUB_EXPORT\n"
			"static void __attribute__((constructor)) dlsub_constructor(void) {\n"
			"\tdlsub_init();\n"
			"}\n"
		);
		fprintf(c_output,
			"#elif _WIN32\n"
			"extern void *__stdcall LoadLibraryA(const char *);\n"
			"extern int (*__stdcall GetProcAddress(void *, const char *))(void);\n"
			"#define DLSUB_GET_DLHANDLE LoadLibraryA\n"
			"#define DLSUB_GET_SYM GetProcAddress\n"
			"#define DLSUB_EXPORT __declspec((dllexport))\n"
			"unsigned __stdcall DllMain(void *instDLL, unsigned reason, void *_reserved) {\n"
			"\t(void)instDLL; (void)_reserved;\n"
			"\tswitch (reason) {\n"
			"\tcase 1: /* DLL loaded */\n"
			"\t\tdlsub_init();\n"
			"\t\tbreak;\n"
			"\tcase 0: /* DLL unloaded */\n"
			"\t\tbreak;\n"
			"}\n"
		);
		fprintf(c_output,
			"#else\n"
			"#error \"Unrecognized OS.\"\n"
			"#endif\n"
		);

		fprintf(c_output, "\n\n");

		while ((semicolon = memchr(preprocessed_headers + c, ';', preprocessed_headers_len - c))) {
			char statement_data[1024], *statement = statement_data;

			{

				int in_line_directive = 0;

				/* get rid of whitespace + line directives before actual statements */
				for (; c < preprocessed_headers_len; ++c) {
					switch (preprocessed_headers[c]) {
					case '\n':
						if (in_line_directive)
							in_line_directive = 0;
						break;
					case '\r':
					case '\t':
					case ' ':
					case '\v':
						break;
					case '#':
						in_line_directive = 1;
						break;
					default:
						if (!in_line_directive)
							goto brk;
						break;
					}
				}
			brk:
				{
					size_t l = (size_t)(semicolon - &preprocessed_headers[c]);
					if (l > sizeof statement_data - 5)
						l = sizeof statement_data - 5;
					memcpy(statement, &preprocessed_headers[c], l);
					statement[l] = 0;
				}
			}

			{
				char *p;
				char *in, *out;
			
				/* remove line directives */
				while ((p = strchr(statement, '#'))) {
					char *end = strchr(p, '\n');
					if (end) {
						memmove(p, end + 1, (size_t)((statement + strlen(statement) + 1) - (end + 1)));
					} else {
						*p = '\0';
					}
				}

				/* normalize whitespace */
				for (p = statement; *p; ++p) {
					if (isspace(*p)) *p = ' ';
				}
				
				/* remove duplicate/unnecessary whitespace */
				for (in = statement, out = statement; *in; ++in) {
					if (in[0] == ' ' && strchr(" (){}*,", in[1])) {
						continue;
					} else if (strchr(" (){}*,", in[0]) && in[1] == ' ') {
						*out++ = *in;
						while (in[1] == ' ') ++in;
					} else {
						*out++ = *in;
					}
				}
				*out = 0;
				
				/* remove leading whitespace */
				if (*statement == ' ')
					++statement;
				/* remove trailing whitespace */
				if (*statement && statement[strlen(statement)-1] == ' ') {
					statement[strlen(statement)-1] = '\0';
				}

				while (statement[0] == '}') {
					/* this can happen with inline functions */
					++statement;
				}

				/* remove "extern" at beginning */
				if (strncmp(statement, "extern ", 7) == 0) {
					statement += 7;
				}

				{
					/* remove GCC's __attribute__ s */
					char *attr;
					while ((attr = strstr(statement, "__attribute__(("))) {
						int paren_level = 2;

						p = attr;

						p += 15;
						for (; *p; ++p) {
							if (paren_level == 0) break;
							switch (*p) {
							case '(': ++paren_level; break;
							case ')': --paren_level; break;
							}
						}
						if (*p == ' ') ++p;
						memmove(attr, p, (size_t)(statement + strlen(statement) + 1 - p));
					}
				}
			}

			if (
				/* these conditions aren't airtight but practically speaking they're good */
				   strlen(statement) < 5 /* shortest possible function declaration is A f(); */
				|| strchr(statement, '(') == NULL
				|| strchr(statement, ')') == NULL
				|| strchr(statement, '{') != NULL
				|| strchr(statement, '}') != NULL
				|| (strncmp(statement, "struct ",  6) == 0)
				|| (strncmp(statement, "enum ",    5) == 0)
				|| (strncmp(statement, "union ",   6) == 0)
				|| (strncmp(statement, "static ",  7) == 0)
				|| (strncmp(statement, "typedef ", 8) == 0)
				) {
				/* not a function declaration */
			} else {
				/* possibly a function declaration */
				char *func_name = statement, *func_name_end;
				if (strncmp(func_name, "const ", 6) == 0) func_name += 6;
				while (is_ident(*func_name)) ++func_name;
				if (*func_name == ' ') ++func_name;
				if (strncmp(func_name, "const ", 6) == 0) func_name += 6;
				
				while (*func_name) {
					if (is_ident(*func_name) && func_name[1] == '(') {
						/* we got it! */
						func_name_end = func_name + 1;
						while (is_ident(*func_name))
							--func_name;
						++func_name;
						break;
					}
					++func_name;
				}

				if (*func_name) {
					SymbolHashEntry *entry;

					*func_name_end = '\0';
					entry = symbol_hash_table_get(&all_symbols, func_name);
					*func_name_end = '(';

					if (!entry) {
						/* ignore this function; it's not part of one of the libraries we're concerned with */
					} else if (entry->declared) {
						/* already processed this function */
					} else {
						entry->declared = 1;
						fprintf(c_output,
							"typedef %.*s (*PTR_%.*s)%.*s;\n"
							"PTR_%.*s REAL_%.*s;\n",
							(int)(func_name - statement),
							statement,
							(int)(func_name_end - func_name),
							func_name,
							(int)(statement + strlen(statement) - func_name_end),
							func_name_end,

							(int)(func_name_end - func_name),
							func_name,
							(int)(func_name_end - func_name),
							func_name
							);
					}
				}

			}
			c = (size_t)(semicolon - preprocessed_headers);
			++c;
		}
		
		{
			size_t s;
			const SymbolHashEntry *entry;
			const char *symbol;
			
			fprintf(nasm_output, "default rel\n");

			for (s = 0; s < all_symbols.n_entries; ++s) {
				entry = all_symbols.entries[s];
				if (!entry) continue;
				symbol = entry->symbol;
				fprintf(nasm_output, "extern REAL_%s\n", symbol);
				if (!entry->declared) {
					fprintf(c_output, "void (*REAL_%s)(void);\n", symbol);
					if (!no_warn)
						fprintf(stderr, "Warning: Function '%s' declared in library, not found in any header file. It will not be usable from C.\n", symbol);
				}
			}

			fprintf(nasm_output, "section .text\n");
			fprintf(c_output, "static void dlsub_init(void) {\n"
				"\tvoid *handle = DLSUB_GET_DLHANDLE(DLSUB_REAL_DL_NAME);\n");

			for (s = 0; s < all_symbols.n_entries; ++s) {
				entry = all_symbols.entries[s];
				if (!entry) continue;
				symbol = entry->symbol;
				fprintf(c_output, "\tREAL_%s = (%s%s)DLSUB_GET_SYM(handle, \"%s\");\n", symbol,
					entry->declared ? "PTR_" : "void (*)(void)", entry->declared ? symbol : "", symbol);
				fprintf(nasm_output, "global %s:function\n", symbol);
			}

		
			for (s = 0; s < all_symbols.n_entries; ++s) {
				entry = all_symbols.entries[s];
				if (!entry) continue;
				symbol = entry->symbol;
				fprintf(nasm_output, "%s: mov r11, [REAL_%s wrt ..gotpc]\njmp [r11]\n", symbol, symbol);
			}
		}

		fprintf(c_output, "}\n");


		fclose(c_output);
		fclose(nasm_output);
	}

	symbol_hash_table_free(&all_symbols);

	return 0;
}