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retroforth/interfaces/rre.c
crc dd8ab89d81 split off file i/o to a separate file 
FossilOrigin-Name: 57450f699decc376e050d03791a2fb48468517ec7874d99623598898d83c7c7d
2018-11-22 05:22:53 +00:00

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/* RETRO --------------------------------------------------------------
A personal, minimalistic forth
Copyright (c) 2016 - 2018 Charles Childers
This is `rre`, short for `run retro and exit`. It's the basic
interface layer for Retro on FreeBSD, Linux and macOS.
rre embeds the image file into the binary, so the compiled version
of this is all you need to have a functional system.
I'll include commentary throughout the source, so read on.
---------------------------------------------------------------------*/
/*---------------------------------------------------------------------
RRE provides numerous extensions to RETRO. Support for these can be
enabled/disabled here. (Note that this won't remove the words, just
support for them. You should also edit `rre.forth` to remove anything
you don't want/need after making changes here).
---------------------------------------------------------------------*/
#define ENABLE_FILES
#define ENABLE_FLOATING_POINT
#define ENABLE_UNIX
#define ENABLE_GOPHER
#define USE_TERMIOS
/*---------------------------------------------------------------------
Begin by including the various C headers needed.
---------------------------------------------------------------------*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <math.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <errno.h>
#include <sys/wait.h>
#include <signal.h>
#ifdef USE_TERMIOS
#include <termios.h>
#include <sys/ioctl.h>
#endif
#define NUM_DEVICES 3
typedef void (*Handler)(void);
Handler IO_deviceHandlers[NUM_DEVICES + 1];
Handler IO_queryHandlers[NUM_DEVICES + 1];
/*---------------------------------------------------------------------
First, a few constants relating to the image format and memory
layout. If you modify the kernel (Rx.md), these will need to be
altered to match your memory layout.
---------------------------------------------------------------------*/
#define TIB 1025
#define D_OFFSET_LINK 0
#define D_OFFSET_XT 1
#define D_OFFSET_CLASS 2
#define D_OFFSET_NAME 3
/*---------------------------------------------------------------------
Next we get into some things that relate to the Nga virtual machine
that RETRO runs on.
---------------------------------------------------------------------*/
#define CELL int32_t /* Cell size (32 bit, signed integer */
#define IMAGE_SIZE 524288 * 48 /* Amount of RAM. 12MiB by default. */
#define ADDRESSES 2048 /* Depth of address stack */
#define STACK_DEPTH 512 /* Depth of data stack */
CELL sp, rp, ip; /* Data, address, instruction pointers */
CELL data[STACK_DEPTH]; /* The data stack */
CELL address[ADDRESSES]; /* The address stack */
CELL memory[IMAGE_SIZE + 1]; /* The memory for the image */
#define TOS data[sp] /* Shortcut for top item on stack */
#define NOS data[sp-1] /* Shortcut for second item on stack */
#define TORS address[rp] /* Shortcut for top item on address stack */
/*---------------------------------------------------------------------
RRE embeds the image into the binary. This includes the image data
(converted to a .c file by an external tool).
---------------------------------------------------------------------*/
#include "rre_image_unix.c"
/*---------------------------------------------------------------------
Moving forward, a few variables. These are updated to point to the
latest values in the image.
---------------------------------------------------------------------*/
CELL Dictionary;
CELL NotFound;
CELL interpret;
/*---------------------------------------------------------------------
Function prototypes.
---------------------------------------------------------------------*/
CELL stack_pop();
void stack_push(CELL value);
CELL string_inject(char *str, CELL buffer);
char *string_extract(CELL at);
CELL d_link(CELL dt);
CELL d_xt(CELL dt);
CELL d_class(CELL dt);
CELL d_name(CELL dt);
CELL d_lookup(CELL Dictionary, char *name);
CELL d_xt_for(char *Name, CELL Dictionary);
void update_rx();
void execute(CELL cell, int silent);
void evaluate(char *s, int silent);
int not_eol(int ch);
void read_token(FILE *file, char *token_buffer, int echo);
void include_file(char *fname, int run_tests);
void ngaGopherUnit();
void ngaFloatingPointUnit();
CELL ngaLoadImage(char *imageFile);
void ngaPrepare();
void ngaProcessOpcode(CELL opcode);
void ngaProcessPackedOpcodes(CELL opcode);
int ngaValidatePackedOpcodes(CELL opcode);
/*---------------------------------------------------------------------
Declare global variables related to I/O.
---------------------------------------------------------------------*/
char **sys_argv;
int sys_argc;
int silence_input;
/*---------------------------------------------------------------------
Now to the fun stuff: interfacing with the virtual machine. There are
a things I like to have here:
- push a value to the stack
- pop a value off the stack
- extract a string from the image
- inject a string into the image.
- lookup dictionary headers and access dictionary fields
---------------------------------------------------------------------*/
/*---------------------------------------------------------------------
Stack push/pop is easy. I could avoid these, but it aids in keeping
the code readable, so it's worth the slight overhead.
---------------------------------------------------------------------*/
CELL stack_pop() {
sp--;
if (sp < 0) {
printf("Data stack underflow.\n");
exit(1);
}
return data[sp + 1];
}
void stack_push(CELL value) {
sp++;
if (sp >= STACK_DEPTH) {
printf("Data stack overflow.\n");
exit(1);
}
data[sp] = value;
}
/*---------------------------------------------------------------------
Strings are next. RETRO uses C-style NULL terminated strings. So I
can easily inject or extract a string. Injection iterates over the
string, copying it into the image. This also takes care to ensure
that the NULL terminator is added.
---------------------------------------------------------------------*/
CELL string_inject(char *str, CELL buffer) {
CELL m, i;
if (!str) {
memory[buffer] = 0;
return 0;
}
m = strlen(str);
i = 0;
while (m > 0) {
memory[buffer + i] = (CELL)str[i];
memory[buffer + i + 1] = 0;
m--; i++;
}
return buffer;
}
/*---------------------------------------------------------------------
Extracting a string is similar, but I have to iterate over the VM
memory instead of a C string and copy the charaters into a buffer.
This uses a static buffer (`string_data`) as I prefer to avoid using
`malloc()`.
---------------------------------------------------------------------*/
char string_data[8192];
char *string_extract(CELL at) {
CELL starting = at;
CELL i = 0;
while(memory[starting] && i < 8192)
string_data[i++] = (char)memory[starting++];
string_data[i] = 0;
return (char *)string_data;
}
/*---------------------------------------------------------------------
Continuing along, I now define functions to access the dictionary.
RETRO's dictionary is a linked list. Each entry is setup like:
0000 Link to previous entry (NULL if this is the root entry)
0001 Pointer to definition start
0002 Pointer to class handler
0003 Start of a NULL terminated string with the word name
First, functions to access each field. The offsets were defineed at
the start of the file.
---------------------------------------------------------------------*/
CELL d_link(CELL dt) {
return dt + D_OFFSET_LINK;
}
CELL d_xt(CELL dt) {
return dt + D_OFFSET_XT;
}
CELL d_class(CELL dt) {
return dt + D_OFFSET_CLASS;
}
CELL d_name(CELL dt) {
return dt + D_OFFSET_NAME;
}
/*---------------------------------------------------------------------
Next, a more complext word. This will walk through the entries to
find one with a name that matches the specified name. This is *slow*,
but works ok unless you have a really large dictionary. (I've not
run into issues with this in practice).
---------------------------------------------------------------------*/
CELL d_lookup(CELL Dictionary, char *name) {
CELL dt = 0;
CELL i = Dictionary;
char *dname;
while (memory[i] != 0 && i != 0) {
dname = string_extract(d_name(i));
if (strcmp(dname, name) == 0) {
dt = i;
i = 0;
} else {
i = memory[i];
}
}
return dt;
}
/*---------------------------------------------------------------------
My last dictionary related word returns the `xt` pointer for a word.
This is used to help keep various important bits up to date.
---------------------------------------------------------------------*/
CELL d_xt_for(char *Name, CELL Dictionary) {
return memory[d_xt(d_lookup(Dictionary, Name))];
}
/*---------------------------------------------------------------------
This interface tracks a few words and variables in the image. These
are:
Dictionary - the latest dictionary header
NotFound - called when a word is not found
interpret - the heart of the interpreter/compiler
I have to call this periodically, as the Dictionary will change as
new words are defined, and the user might write a new error handler
or interpreter.
---------------------------------------------------------------------*/
void update_rx() {
Dictionary = memory[2];
interpret = d_xt_for("interpret", Dictionary);
NotFound = d_xt_for("err:notfound", Dictionary);
}
/*---------------------------------------------------------------------
Now on to I/O and extensions!
RRE provides a lot of additional functionality over the base RETRO
system. First up is support for files.
The RRE file model is intended to be similar to that of the standard
C libraries and wraps fopen(), fclose(), etc.
---------------------------------------------------------------------*/
void generic_output() {
putc(stack_pop(), stdout);
fflush(stdout);
}
void generic_output_query() {
stack_push(0);
stack_push(0);
}
void io_keyboard_handler() {
stack_push(getc(stdin));
if (TOS == 127) TOS = 8;
#ifdef USE_TERMIOS
if (silence_input != -1) {
putc(TOS, stdout);
fflush(stdout);
}
#endif
}
void io_keyboard_query() {
stack_push(0);
stack_push(1);
}
#ifdef ENABLE_FILES
#define MAX_OPEN_FILES 128
extern FILE *ioFileHandles[MAX_OPEN_FILES];
CELL ioGetFileHandle();
void io_filesystem_query();
void io_filesystem_handler();
#endif
/*---------------------------------------------------------------------
UNIX. Or Linux. Or BSD. Or whatever. This section adds functions for
interacting with the host OS. It's tested on FreeBSD and Linux, but
likely won't work on Windows or any other host not supporting POSIX.
---------------------------------------------------------------------*/
#ifdef ENABLE_UNIX
/*---------------------------------------------------------------------
First step is to define the instruction values for each of these.
---------------------------------------------------------------------*/
#define RRE_UNIX_SYSTEM -8000
#define RRE_UNIX_FORK -8001
#define RRE_UNIX_EXIT -8002
#define RRE_UNIX_GETPID -8003
#define RRE_UNIX_EXEC0 -8004
#define RRE_UNIX_EXEC1 -8005
#define RRE_UNIX_EXEC2 -8006
#define RRE_UNIX_EXEC3 -8007
#define RRE_UNIX_WAIT -8008
#define RRE_UNIX_KILL -8009
#define RRE_UNIX_POPEN -8010
#define RRE_UNIX_PCLOSE -8011
#define RRE_UNIX_WRITE -8012
#define RRE_UNIX_CHDIR -8013
#define RRE_UNIX_GETENV -8014
#define RRE_UNIX_PUTENV -8015
#define RRE_UNIX_SLEEP -8016
#define RRE_UNIX_IO_PUTN -8100
#define RRE_UNIX_IO_PUTS -8101
/*---------------------------------------------------------------------
`unixOpenPipe()` is like `ioOpenFile()`, but for pipes. This pulls
from the data stack:
- mode (number, TOS)
- executable (string, NOS)
Modes are:
| Mode | Corresponds To | Description |
| ---- | -------------- | -------------------- |
| 0 | r | Open for reading |
| 1 | w | Open for writing |
| 3 | r+ | Open for read/update |
The file name should be a NULL terminated string. This will attempt
to open the requested file and will return a handle (index number
into the `ioFileHandles` array).
Once opened, you can use the standard file words to read/write to the
process.
---------------------------------------------------------------------*/
CELL unixOpenPipe() {
CELL slot, mode, name;
char *request;
slot = ioGetFileHandle();
mode = stack_pop();
name = stack_pop();
request = string_extract(name);
if (slot > 0) {
if (mode == 0) ioFileHandles[slot] = popen(request, "r");
if (mode == 1) ioFileHandles[slot] = popen(request, "w");
if (mode == 3) ioFileHandles[slot] = popen(request, "r+");
}
if (ioFileHandles[slot] == NULL) {
ioFileHandles[slot] = 0;
slot = 0;
}
stack_push(slot);
return slot;
}
/*---------------------------------------------------------------------
`unixClosePipe()` closes an open pipe. This takes a file handle from
the stack.
---------------------------------------------------------------------*/
CELL unixClosePipe() {
pclose(ioFileHandles[data[sp]]);
ioFileHandles[data[sp]] = 0;
sp--;
return 0;
}
/*---------------------------------------------------------------------
`unix_system()` executes a shell command. This takes a string and
will execute it by calling the shell, returning to RRE after
execution completes.
---------------------------------------------------------------------*/
void unix_system() {
system(string_extract(stack_pop()));
}
/*---------------------------------------------------------------------
`unix_fork()` creates a new process. This returns a new process ID on
the stack.
---------------------------------------------------------------------*/
void unix_fork() {
stack_push(fork());
}
/*---------------------------------------------------------------------
UNIX provides `execl` to execute a file, with various forms for
arguments provided.
RRE wraps this in several functions, one for each number of passed
arguments. See the Glossary for details on what each takes from the
stack. Each of these will return the error code if the execution
fails.
---------------------------------------------------------------------*/
void unix_exec0() {
char path[1024];
strcpy(path, string_extract(stack_pop()));
execl(path, path, (char *)0);
stack_push(errno);
}
void unix_exec1() {
char path[1024];
char arg0[1024];
strcpy(arg0, string_extract(stack_pop()));
strcpy(path, string_extract(stack_pop()));
execl(path, path, arg0, (char *)0);
stack_push(errno);
}
void unix_exec2() {
char path[1024];
char arg0[1024], arg1[1024];
strcpy(arg1, string_extract(stack_pop()));
strcpy(arg0, string_extract(stack_pop()));
strcpy(path, string_extract(stack_pop()));
execl(path, path, arg0, arg1, (char *)0);
stack_push(errno);
}
void unix_exec3() {
char path[1024];
char arg0[1024], arg1[1024], arg2[1024];
strcpy(arg2, string_extract(stack_pop()));
strcpy(arg1, string_extract(stack_pop()));
strcpy(arg0, string_extract(stack_pop()));
strcpy(path, string_extract(stack_pop()));
execl(path, path, arg0, arg1, arg2, (char *)0);
stack_push(errno);
}
/*---------------------------------------------------------------------
`unix_exit()` exits RRE with a return code of the top value on the
stack.
---------------------------------------------------------------------*/
void unix_exit() {
exit(stack_pop());
}
/*---------------------------------------------------------------------
---------------------------------------------------------------------*/
void unix_getpid() {
stack_push(getpid());
}
/*---------------------------------------------------------------------
---------------------------------------------------------------------*/
void unix_wait() {
CELL a;
stack_push(wait(&a));
}
/*---------------------------------------------------------------------
---------------------------------------------------------------------*/
void unix_kill() {
CELL a;
a = stack_pop();
kill(stack_pop(), a);
}
/*---------------------------------------------------------------------
---------------------------------------------------------------------*/
void unix_write() {
CELL a, b, c;
c = stack_pop();
b = stack_pop();
a = stack_pop();
write(fileno(ioFileHandles[c]), string_extract(a), b);
}
/*---------------------------------------------------------------------
---------------------------------------------------------------------*/
void unix_chdir() {
chdir(string_extract(stack_pop()));
}
/*---------------------------------------------------------------------
---------------------------------------------------------------------*/
void unix_getenv() {
CELL a, b;
a = stack_pop();
b = stack_pop();
string_inject(getenv(string_extract(b)), a);
}
/*---------------------------------------------------------------------
---------------------------------------------------------------------*/
void unix_putenv() {
putenv(string_extract(stack_pop()));
}
/*---------------------------------------------------------------------
---------------------------------------------------------------------*/
void unix_sleep() {
sleep(stack_pop());
}
/*---------------------------------------------------------------------
---------------------------------------------------------------------*/
void unix_io_putn() {
printf("%ld", (long)stack_pop());
}
/*---------------------------------------------------------------------
---------------------------------------------------------------------*/
void unix_io_puts() {
printf("%s", string_extract(stack_pop()));
}
/*---------------------------------------------------------------------
---------------------------------------------------------------------*/
void ngaUnixUnit() {
switch (stack_pop()) {
case RRE_UNIX_SYSTEM: unix_system(); break;
case RRE_UNIX_FORK: unix_fork(); break;
case RRE_UNIX_EXEC0: unix_exec0(); break;
case RRE_UNIX_EXEC1: unix_exec1(); break;
case RRE_UNIX_EXEC2: unix_exec2(); break;
case RRE_UNIX_EXEC3: unix_exec3(); break;
case RRE_UNIX_EXIT: unix_exit(); break;
case RRE_UNIX_GETPID: unix_getpid(); break;
case RRE_UNIX_WAIT: unix_wait(); break;
case RRE_UNIX_KILL: unix_kill(); break;
case RRE_UNIX_POPEN: unixOpenPipe(); break;
case RRE_UNIX_PCLOSE: unixClosePipe(); break;
case RRE_UNIX_WRITE: unix_write(); break;
case RRE_UNIX_CHDIR: unix_chdir(); break;
case RRE_UNIX_GETENV: unix_getenv(); break;
case RRE_UNIX_PUTENV: unix_putenv(); break;
case RRE_UNIX_SLEEP: unix_sleep(); break;
case RRE_UNIX_IO_PUTN: unix_io_putn(); break;
case RRE_UNIX_IO_PUTS: unix_io_puts(); break;
default: break;
}
}
#endif
/*---------------------------------------------------------------------
Floating Point.
I kind of dislike floating point (it's tricky, and not as precise as
fixed point), but it is useful for certain things. I include support
for it as it's been requested frequently by my users.
---------------------------------------------------------------------*/
#ifdef ENABLE_FLOATING_POINT
/*---------------------------------------------------------------------
I have a stack of floating point values ("floats") and a stack
pointer (`fsp`).
---------------------------------------------------------------------*/
double Floats[8192];
CELL fsp;
/*---------------------------------------------------------------------
The first two functions push a float to the stack and pop a value off
the stack.
---------------------------------------------------------------------*/
void float_push(double value) {
fsp++;
Floats[fsp] = value;
}
double float_pop() {
fsp--;
return Floats[fsp + 1];
}
/*---------------------------------------------------------------------
RETRO operates on 32-bit signed integer values. This function just
pops a number from the data stack, casts it to a float, and pushes it
to the float stack.
---------------------------------------------------------------------*/
void float_from_number() {
float_push((double)stack_pop());
}
/*---------------------------------------------------------------------
To get a float from a string in the image, I provide this function.
I cheat: using `atof()` takes care of the details, so I don't have
to.
---------------------------------------------------------------------*/
void float_from_string() {
float_push(atof(string_extract(stack_pop())));
}
/*---------------------------------------------------------------------
Converting a floating point into a string is slightly more work. Here
I pass it off to `snprintf()` to deal with.
---------------------------------------------------------------------*/
void float_to_string() {
snprintf(string_data, 8192, "%f", float_pop());
string_inject(string_data, stack_pop());
}
/*---------------------------------------------------------------------
Converting a floating point back into a standard number requires a
little care due to the signed nature. This makes adjustments for the
max & min value, and then casts (rounding) the float back to a normal
number.
---------------------------------------------------------------------*/
void float_to_number() {
double a = float_pop();
if (a > 2147483647)
a = 2147483647;
if (a < -2147483648)
a = -2147483648;
stack_push((CELL)round(a));
}
/*---------------------------------------------------------------------
Now I get to define a bunch of functions that operate on floats.
These provide the basic math, and wrappers around functionality in
libm.
---------------------------------------------------------------------*/
void float_add() {
double a = float_pop();
double b = float_pop();
float_push(a+b);
}
void float_sub() {
double a = float_pop();
double b = float_pop();
float_push(b-a);
}
void float_mul() {
double a = float_pop();
double b = float_pop();
float_push(a*b);
}
void float_div() {
double a = float_pop();
double b = float_pop();
float_push(b/a);
}
void float_floor() {
float_push(floor(float_pop()));
}
void float_ceil() {
float_push(ceil(float_pop()));
}
void float_eq() {
double a = float_pop();
double b = float_pop();
if (a == b)
stack_push(-1);
else
stack_push(0);
}
void float_neq() {
double a = float_pop();
double b = float_pop();
if (a != b)
stack_push(-1);
else
stack_push(0);
}
void float_lt() {
double a = float_pop();
double b = float_pop();
if (b < a)
stack_push(-1);
else
stack_push(0);
}
void float_gt() {
double a = float_pop();
double b = float_pop();
if (b > a)
stack_push(-1);
else
stack_push(0);
}
void float_depth() {
stack_push(fsp);
}
void float_dup() {
double a = float_pop();
float_push(a);
float_push(a);
}
void float_drop() {
float_pop();
}
void float_swap() {
double a = float_pop();
double b = float_pop();
float_push(a);
float_push(b);
}
void float_log() {
double a = float_pop();
double b = float_pop();
float_push(log(b) / log(a));
}
void float_sqrt() {
float_push(sqrt(float_pop()));
}
void float_pow() {
double a = float_pop();
double b = float_pop();
float_push(pow(b, a));
}
void float_sin() {
float_push(sin(float_pop()));
}
void float_cos() {
float_push(cos(float_pop()));
}
void float_tan() {
float_push(tan(float_pop()));
}
void float_asin() {
float_push(asin(float_pop()));
}
void float_acos() {
float_push(acos(float_pop()));
}
void float_atan() {
float_push(atan(float_pop()));
}
/*---------------------------------------------------------------------
With this finally done, I implement the FPU instructions.
---------------------------------------------------------------------*/
Handler FloatHandlers[] = {
float_from_number,
float_from_string,
float_to_number,
float_to_string,
float_add,
float_sub,
float_mul,
float_div,
float_floor,
float_ceil,
float_sqrt,
float_eq,
float_neq,
float_lt,
float_gt,
float_depth,
float_dup,
float_drop,
float_swap,
float_log,
float_pow,
float_sin,
float_tan,
float_cos,
float_asin,
float_acos,
float_atan
};
void ngaFloatingPointUnit() {
switch (stack_pop()) {
case 0: float_from_number(); break;
case 1: float_from_string(); break;
case 2: float_to_string(); break;
case 3: float_add(); break;
case 4: float_sub(); break;
case 5: float_mul(); break;
case 6: float_div(); break;
case 7: float_floor(); break;
case 8: float_eq(); break;
case 9: float_neq(); break;
case 10: float_lt(); break;
case 11: float_gt(); break;
case 12: float_depth(); break;
case 13: float_dup(); break;
case 14: float_drop(); break;
case 15: float_swap(); break;
case 16: float_log(); break;
case 17: float_pow(); break;
case 18: float_to_number(); break;
case 19: float_sin(); break;
case 20: float_cos(); break;
case 21: float_tan(); break;
case 22: float_asin(); break;
case 23: float_acos(); break;
case 24: float_atan(); break;
case 25: float_ceil(); break;
case 26: float_sqrt(); break;
default: break;
}
}
#endif
/*---------------------------------------------------------------------
Gopher Support
I'm a big fan of Gopher, so RRE provides support for fetching files
via the Gopher protocol.
---------------------------------------------------------------------*/
#ifdef ENABLE_GOPHER
/*---------------------------------------------------------------------
The first Gopher related function is `error()`, which prints an
error message and exits if there is a problem.
---------------------------------------------------------------------*/
void error(const char *msg) {
perror(msg);
exit(0);
}
/*---------------------------------------------------------------------
`gopher_fetch()` is the part that does all the real work.
---------------------------------------------------------------------*/
void gopher_fetch(char *host, CELL port, char *selector, CELL dest) {
int sockfd, portno, n;
struct sockaddr_in serv_addr;
struct hostent *server;
char data[128 * 1024 + 1];
char buffer[1025];
portno = (int)port;
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd < 0)
error("ERROR opening socket");
server = gethostbyname(host);
if (server == NULL) {
fprintf(stderr,"ERROR, no such host\n");
exit(0);
}
bzero(data, 128 * 1024 + 1);
bzero((char *) &serv_addr, sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
bcopy((char *)server->h_addr,
(char *)&serv_addr.sin_addr.s_addr,
server->h_length);
serv_addr.sin_port = htons(portno);
if (connect(sockfd,(struct sockaddr *) &serv_addr,sizeof(serv_addr)) < 0)
error("ERROR connecting");
n = write(sockfd,selector,strlen(selector));
if (n < 0)
error("ERROR writing to socket");
n = write(sockfd,"\n",strlen("\n"));
if (n < 0)
error("ERROR writing to socket");
n = 1;
while (n > 0) {
bzero(buffer,1025);
n = read(sockfd,buffer,1024);
strcat(data, buffer);
}
close(sockfd);
string_inject(data, dest);
stack_push(strlen(data));
}
/*---------------------------------------------------------------------
The last Gopher function, `ngaGopherUnit()` pulls the values needed
from the stack and passes them to the `gopher_fetch()` function.
This will take the following from the stack (TOS to bottom):
Selector (NULL terminated string)
Port (Number)
Server (NULL terminated string)
Buffer (Pointer to memory that will hold the received file)
---------------------------------------------------------------------*/
void ngaGopherUnit() {
CELL port, dest;
char server[1025], selector[4097];
strcpy(selector, string_extract(stack_pop()));
port = stack_pop();
strcpy(server, string_extract(stack_pop()));
dest = stack_pop();
gopher_fetch(server, port, selector, dest);
}
#endif
/*---------------------------------------------------------------------
---------------------------------------------------------------------*/
#ifdef USE_TERMIOS
struct termios new_termios, old_termios;
void prepare_term() {
tcgetattr(0, &old_termios);
new_termios = old_termios;
new_termios.c_iflag &= ~(BRKINT+ISTRIP+IXON+IXOFF);
new_termios.c_iflag |= (IGNBRK+IGNPAR);
new_termios.c_lflag &= ~(ICANON+ISIG+IEXTEN+ECHO);
new_termios.c_cc[VMIN] = 1;
new_termios.c_cc[VTIME] = 0;
tcsetattr(0, TCSANOW, &new_termios);
}
void restore_term() {
tcsetattr(0, TCSANOW, &old_termios);
}
#endif
/*---------------------------------------------------------------------
With these out of the way, I implement `execute`, which takes an
address and runs the code at it. This has a couple of interesting
bits.
Nga uses packed instruction bundles, with up to four instructions per
bundle. Since RETRO requires an additional instruction to handle
displaying a character, I define the handler for that here.
This will also exit if the address stack depth is zero (meaning that
the word being run, and it's dependencies) are finished.
---------------------------------------------------------------------*/
void execute(CELL cell, int silent) {
CELL a, b, token;
CELL opcode;
silence_input = silent;
rp = 1;
ip = cell;
token = TIB;
while (ip < IMAGE_SIZE) {
if (ip == NotFound) {
printf("\nERROR: Word Not Found: ");
printf("`%s`\n\n", string_extract(token));
}
if (ip == interpret) {
token = TOS;
}
opcode = memory[ip];
if (ngaValidatePackedOpcodes(opcode) != 0) {
ngaProcessPackedOpcodes(opcode);
} else if (opcode >= 0 && opcode < 27) {
ngaProcessOpcode(opcode);
} else {
switch (opcode) {
case -9999: include_file(string_extract(stack_pop()), 0); break;
#ifdef ENABLE_FLOATING_POINT
case -6000: ngaFloatingPointUnit(); break;
#endif
case -6100: stack_push(sys_argc - 2); break;
case -6101: a = stack_pop();
b = stack_pop();
stack_push(string_inject(sys_argv[a + 2], b));
break;
#ifdef ENABLE_GOPHER
case -6200: ngaGopherUnit(); break;
#endif
#ifdef ENABLE_UNIX
case -6300: ngaUnixUnit(); break;
#endif
default: printf("Invalid instruction!\n");
printf("At %d, opcode %d\n", ip, opcode);
#ifdef USE_TERMIOS
restore_term();
#endif
exit(1);
}
}
ip++;
if (rp == 0)
ip = IMAGE_SIZE;
}
}
/*---------------------------------------------------------------------
RETRO's `interpret` word expects a token on the stack. This next
function copies a token to the `TIB` (text input buffer) and then
calls `interpret` to process it.
---------------------------------------------------------------------*/
void evaluate(char *s, int silent) {
if (strlen(s) == 0)
return;
update_rx();
string_inject(s, TIB);
stack_push(TIB);
execute(interpret, silent);
}
/*---------------------------------------------------------------------
`read_token` reads a token from the specified file. It will stop on
a whitespace or newline. It also tries to handle backspaces, though
the success of this depends on how your terminal is configured.
---------------------------------------------------------------------*/
int not_eol(int ch) {
return (ch != (char)10) && (ch != (char)13) && (ch != (char)32) && (ch != EOF) && (ch != 0);
}
void read_token(FILE *file, char *token_buffer, int echo) {
int ch = getc(file);
int count = 0;
if (echo != 0)
putchar(ch);
while (not_eol(ch))
{
if ((ch == 8 || ch == 127) && count > 0) {
count--;
if (echo != 0) {
putchar(8);
putchar(32);
putchar(8);
}
} else {
token_buffer[count++] = ch;
}
ch = getc(file);
if (echo != 0)
putchar(ch);
}
token_buffer[count] = '\0';
}
/*---------------------------------------------------------------------
---------------------------------------------------------------------*/
void dump_stack() {
CELL i;
if (sp == 0)
return;
printf("\nStack: ");
for (i = 1; i <= sp; i++) {
if (i == sp)
printf("[ TOS: %d ]", data[i]);
else
printf("%d ", data[i]);
}
printf("\n");
}
/*---------------------------------------------------------------------
RRE is primarily intended to be used in a batch or scripting model.
The `include_file()` function will be used to read the code in the
file, evaluating it as encountered.
I enforce a literate model, with code in fenced blocks. E.g.,
# This is a test
Display "Hello, World!"
~~~
'Hello,_World! puts nl
~~~
RRE will ignore anything outside the `~~~` blocks. To identify if the
current token is the start or end of a block, I provide a `fenced()`
function.
---------------------------------------------------------------------*/
int fenced(char *s)
{
int a = strcmp(s, "```");
int b = strcmp(s, "~~~");
if (a == 0) return 2;
if (b == 0) return 1;
return 0;
}
/*---------------------------------------------------------------------
And now for the actual `include_file()` function.
---------------------------------------------------------------------*/
void include_file(char *fname, int run_tests) {
int inBlock = 0; /* Tracks status of in/out of block */
char source[64 * 1024]; /* Line buffer [about 64K] */
char fence[4]; /* Used with `fenced()` */
FILE *fp; /* Open the file. If not found, */
fp = fopen(fname, "r"); /* exit. */
if (fp == NULL)
return;
while (!feof(fp)) /* Loop through the file */
{
read_token(fp, source, 0);
strncpy(fence, source, 3); /* Copy the first three characters */
fence[3] = '\0'; /* into `fence` to see if we are in */
if (fenced(fence) > 0) { /* a code block. */
if (fenced(fence) == 2 && run_tests == 0) {
} else {
if (inBlock == 0)
inBlock = 1;
else
inBlock = 0;
}
} else {
if (inBlock == 1) /* If we are, evaluate token */
evaluate(source, -1);
}
}
fclose(fp);
}
/*---------------------------------------------------------------------
`help()` displays a summary of the command line arguments RRE allows.
This is invoked using `rre -h`
---------------------------------------------------------------------*/
void help(char *exename) {
printf("Scripting Usage: %s filename\n\n", exename);
printf("Interactive Usage: %s [-h] [-i] [-c] [-s] [-f filename] [-t]\n\n", exename);
printf("Valid Arguments:\n\n");
printf(" -h\n");
printf(" Display this help text\n\n");
printf(" -i\n");
printf(" Launches in interactive mode (line buffered)\n\n");
printf(" -c\n");
printf(" Launches in interactive mode (character buffered)\n\n");
printf(" -s\n");
printf(" Suppress the 'ok' prompt and keyboard echo in interactive mode\n\n");
printf(" -f filename\n");
printf(" Run the contents of the specified file\n\n");
printf(" -t\n");
printf(" Run tests (in ``` blocks) in any loaded files\n\n");
}
/*---------------------------------------------------------------------
`initialize()` sets up Nga and loads the image (from the array in
`image.c`) to memory.
---------------------------------------------------------------------*/
void initialize() {
CELL i;
ngaPrepare();
for (i = 0; i < ngaImageCells; i++)
memory[i] = ngaImage[i];
update_rx();
}
/*---------------------------------------------------------------------
`arg_is()` exists to aid in readability. It compares the first actual
command line argument to a string and returns a boolean flag.
---------------------------------------------------------------------*/
int arg_is(char *t) {
return strcmp(sys_argv[1], t) == 0;
}
/*---------------------------------------------------------------------
---------------------------------------------------------------------*/
enum flags {
FLAG_HELP, FLAG_RUN_TESTS, FLAG_INCLUDE, FLAG_INTERACTIVE, FLAG_CBREAK, FLAG_SILENT
};
int main(int argc, char **argv) {
int i;
int modes[32];
char *files[16];
int fsp;
int run_tests;
if (argc <= 1) return 0; /* Guard clause: exit if no */
/* arguments are passed. */
initialize(); /* Initialize Nga & image */
IO_deviceHandlers[0] = generic_output;
IO_queryHandlers[0] = generic_output_query;
IO_deviceHandlers[1] = io_keyboard_handler;
IO_queryHandlers[1] = io_keyboard_query;
IO_deviceHandlers[2] = io_filesystem_handler;
IO_queryHandlers[2] = io_filesystem_query;
sys_argc = argc; /* Point the global argc and */
sys_argv = argv; /* argv to the actual ones */
if (argc >= 2 && argv[1][0] != '-') {
include_file(argv[1], 0); /* If no flags were passed, */
if (sp >= 1) dump_stack(); /* load the file specified, */
exit(0); /* and exit */
}
for (i = 0; i < 32; i++)
modes[i] = 0;
for (i = 0; i < 16; i++)
files[i] = "\0";
run_tests = 0;
fsp = 0;
for (i = 1; i < argc; i++) {
if (strcmp(argv[i], "-h") == 0) {
help(argv[0]);
exit(0);
} else if (strcmp(argv[i], "-i") == 0) {
modes[FLAG_INTERACTIVE] = 1;
} else if (strcmp(argv[i], "-c") == 0) {
modes[FLAG_INTERACTIVE] = 1;
modes[FLAG_CBREAK] = 1;
} else if (strcmp(argv[i], "-s") == 0) {
modes[FLAG_SILENT] = 1;
} else if (strcmp(argv[i], "-f") == 0) {
files[fsp] = argv[i + 1];
fsp++;
i++;
} else if (strcmp(argv[i], "-t") == 0) {
modes[FLAG_RUN_TESTS] = 1;
run_tests = 1;
}
}
for (i = 0; i < fsp; i++) {
if (strcmp(files[i], "\0") != 0)
include_file(files[i], run_tests);
}
if (modes[FLAG_SILENT] == 1) {
memory[d_xt_for("NoEcho", Dictionary)] = -1;
}
if (modes[FLAG_INTERACTIVE] == 1) {
execute(d_xt_for("banner", Dictionary), 0);
#ifdef USE_TERMIOS
if (modes[FLAG_CBREAK] == 1) prepare_term();
#endif
if (modes[FLAG_CBREAK] == 1) while (1) execute(d_xt_for("listen", Dictionary), 0);
if (modes[FLAG_CBREAK] == 0) while (1) execute(d_xt_for("listen", Dictionary), -1);
#ifdef USE_TERMIOS
if (modes[FLAG_CBREAK] == 1) restore_term();
#endif
exit(0);
}
}
/* Nga ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Copyright (c) 2008 - 2018, Charles Childers
Copyright (c) 2009 - 2010, Luke Parrish
Copyright (c) 2010, Marc Simpson
Copyright (c) 2010, Jay Skeer
Copyright (c) 2011, Kenneth Keating
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
enum vm_opcode {
VM_NOP, VM_LIT, VM_DUP, VM_DROP, VM_SWAP, VM_PUSH, VM_POP,
VM_JUMP, VM_CALL, VM_CCALL, VM_RETURN, VM_EQ, VM_NEQ, VM_LT,
VM_GT, VM_FETCH, VM_STORE, VM_ADD, VM_SUB, VM_MUL, VM_DIVMOD,
VM_AND, VM_OR, VM_XOR, VM_SHIFT, VM_ZRET, VM_END, VM_IE,
VM_IQ, VM_II
};
#define NUM_OPS VM_II + 1
#ifndef NUM_DEVICES
#define NUM_DEVICES 0
#endif
//Handler IO_deviceHandlers[NUM_DEVICES + 1];
//Handler IO_queryHandlers[NUM_DEVICES + 1];
CELL ngaLoadImage(char *imageFile) {
FILE *fp;
CELL imageSize;
long fileLen;
CELL i;
if ((fp = fopen(imageFile, "rb")) != NULL) {
/* Determine length (in cells) */
fseek(fp, 0, SEEK_END);
fileLen = ftell(fp) / sizeof(CELL);
rewind(fp);
/* Read the file into memory */
imageSize = fread(&memory, sizeof(CELL), fileLen, fp);
fclose(fp);
}
else {
for (i = 0; i < ngaImageCells; i++)
memory[i] = ngaImage[i];
imageSize = i;
}
return imageSize;
}
void ngaPrepare() {
ip = sp = rp = 0;
for (ip = 0; ip < IMAGE_SIZE; ip++)
memory[ip] = VM_NOP;
for (ip = 0; ip < STACK_DEPTH; ip++)
data[ip] = 0;
for (ip = 0; ip < ADDRESSES; ip++)
address[ip] = 0;
}
void inst_nop() {
}
void inst_lit() {
sp++;
ip++;
TOS = memory[ip];
}
void inst_dup() {
sp++;
data[sp] = NOS;
}
void inst_drop() {
data[sp] = 0;
if (--sp < 0)
ip = IMAGE_SIZE;
}
void inst_swap() {
CELL a;
a = TOS;
TOS = NOS;
NOS = a;
}
void inst_push() {
rp++;
TORS = TOS;
inst_drop();
}
void inst_pop() {
sp++;
TOS = TORS;
rp--;
}
void inst_jump() {
ip = TOS - 1;
inst_drop();
}
void inst_call() {
rp++;
TORS = ip;
ip = TOS - 1;
inst_drop();
}
void inst_ccall() {
CELL a, b;
a = TOS; inst_drop(); /* False */
b = TOS; inst_drop(); /* Flag */
if (b != 0) {
rp++;
TORS = ip;
ip = a - 1;
}
}
void inst_return() {
ip = TORS;
rp--;
}
void inst_eq() {
NOS = (NOS == TOS) ? -1 : 0;
inst_drop();
}
void inst_neq() {
NOS = (NOS != TOS) ? -1 : 0;
inst_drop();
}
void inst_lt() {
NOS = (NOS < TOS) ? -1 : 0;
inst_drop();
}
void inst_gt() {
NOS = (NOS > TOS) ? -1 : 0;
inst_drop();
}
void inst_fetch() {
switch (TOS) {
case -1: TOS = sp - 1; break;
case -2: TOS = rp; break;
case -3: TOS = IMAGE_SIZE; break;
default: TOS = memory[TOS]; break;
}
}
void inst_store() {
if (TOS <= IMAGE_SIZE && TOS >= 0) {
memory[TOS] = NOS;
inst_drop();
inst_drop();
} else {
ip = IMAGE_SIZE;
}
}
void inst_add() {
NOS += TOS;
inst_drop();
}
void inst_sub() {
NOS -= TOS;
inst_drop();
}
void inst_mul() {
NOS *= TOS;
inst_drop();
}
void inst_divmod() {
CELL a, b;
a = TOS;
b = NOS;
TOS = b / a;
NOS = b % a;
}
void inst_and() {
NOS = TOS & NOS;
inst_drop();
}
void inst_or() {
NOS = TOS | NOS;
inst_drop();
}
void inst_xor() {
NOS = TOS ^ NOS;
inst_drop();
}
void inst_shift() {
CELL y = TOS;
CELL x = NOS;
if (TOS < 0)
NOS = NOS << (TOS * -1);
else {
if (x < 0 && y > 0)
NOS = x >> y | ~(~0U >> y);
else
NOS = x >> y;
}
inst_drop();
}
void inst_zret() {
if (TOS == 0) {
inst_drop();
ip = TORS;
rp--;
}
}
void inst_end() {
ip = IMAGE_SIZE;
}
void inst_ie() {
sp++;
TOS = NUM_DEVICES;
}
void inst_iq() {
CELL Device = TOS;
inst_drop();
IO_queryHandlers[Device]();
}
void inst_ii() {
CELL Device = TOS;
inst_drop();
IO_deviceHandlers[Device]();
}
Handler instructions[NUM_OPS] = {
inst_nop, inst_lit, inst_dup, inst_drop, inst_swap, inst_push, inst_pop,
inst_jump, inst_call, inst_ccall, inst_return, inst_eq, inst_neq, inst_lt,
inst_gt, inst_fetch, inst_store, inst_add, inst_sub, inst_mul, inst_divmod,
inst_and, inst_or, inst_xor, inst_shift, inst_zret, inst_end, inst_ie,
inst_iq, inst_ii
};
void ngaProcessOpcode(CELL opcode) {
if (opcode != 0)
instructions[opcode]();
}
int ngaValidatePackedOpcodes(CELL opcode) {
CELL raw = opcode;
CELL current;
int valid = -1;
int i;
for (i = 0; i < 4; i++) {
current = raw & 0xFF;
if (!(current >= 0 && current <= 29))
valid = 0;
raw = raw >> 8;
}
return valid;
}
void ngaProcessPackedOpcodes(CELL opcode) {
CELL raw = opcode;
int i;
for (i = 0; i < 4; i++) {
ngaProcessOpcode(raw & 0xFF);
raw = raw >> 8;
}
}
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