acd.c

操作系统源代码

/*	acd 1.9 - A compiler driver			Author: Kees J. Bot
 *								7 Jan 1993
 * Needs about 25kw heap + stack.
 *
 * Copyright 1994 Kees J. Bot, All rights reserved.
 * This program and documentation may be freely used under the following
 * restrictions: Changes that do not increase the functionality or that are
 * incompatible with the original may not be released to the public without
 * permission from the author.  Use of so called "C beautifiers" is explicitly
 * prohibited.
 */
char version[] = "1.9";

#define nil 0
#define _POSIX_SOURCE	1
#include <sys/types.h>
#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <signal.h>
#include <errno.h>
#include <ctype.h>
#include <assert.h>
#include <sys/stat.h>
#include <sys/wait.h>

#ifndef LIB
#define LIB	"/usr/lib"	/* Default library directory. */
#endif

#define arraysize(a)	(sizeof(a) / sizeof((a)[0]))
#define arraylimit(a)	((a) + arraysize(a))

char *program;		/* Call name. */

int verbose= 0;		/* -v0: Silent.
			 * -v1: Show abbreviated pass names.
			 * -v2: Show executed UNIX commands.
			 * -v3: Show executed ACD commands.
			 * -v4: Show descr file as it is read.
			 */

int action= 2;		/*   0: An error occured, don't do anything anymore.
			 *   1: (-vn) Do not execute, play-act.
			 *   2: Execute UNIX commands.
			 */

void report(char *label)
{
	if (label == nil || label[0] == 0) {
		fprintf(stderr, "%s: %s\n", program, strerror(errno));
	} else {
		fprintf(stderr, "%s: %s: %s\n",
					program, label, strerror(errno));
	}
	action= 0;
}

void quit(int exit_code);

void fatal(char *label)
{
	report(label);
	quit(-1);
}

size_t heap_chunks= 0;

void *allocate(void *mem, size_t size)
/* Safe malloc/realloc.  (I have heard that one can call realloc with a
 * null first argument with the effect below, but that is of course to
 * ridiculous to believe.)
 */
{
	assert(size > 0);

	if (mem != nil) {
		mem= realloc(mem, size);
	} else {
		mem= malloc(size);
		heap_chunks++;
	}
	if (mem == nil) fatal(nil);
	return mem;
}

void deallocate(void *mem)
{
	if (mem != nil) {
		free(mem);
		heap_chunks--;
	}
}

char *copystr(const char *s)
{
	char *c;
	c= allocate(nil, (strlen(s)+1) * sizeof(*c));
	strcpy(c, s);
	return c;
}

/* Every object, list, letter, or variable, is made with cells. */
typedef struct cell {
	unsigned short	refc;		/* Reference count. */
	char		type;		/* Type of object. */
	unsigned char	letter;		/* Simply a letter. */
	char		*name;		/* Name of a word. */
	struct cell	*hash;		/* Hash chain. */
	struct cell	*car, *cdr;	/* To form lists. */

/* For a word: */
#	define	value	car		/* Value of a variable. */
#	define	base	cdr		/* Base-name in transformations. */
#	define	suffix	cdr		/* Suffix in a treat-as. */
#	define	flags	letter		/* Special flags. */

/* A substitution: */
#	define	subst	car

} cell_t;

typedef enum type {
	CELL,		/* A list cell. */
	STRING,		/* To make a list of characters and substs. */
	SUBST,		/* Variable to substitute. */
	/* Unique objects. */
	LETTER,		/* A letter. */
	WORD,		/* A string collapses to a word. */
	EQUALS,		/* = operator, etc. */
	OPEN,
	CLOSE,
	PLUS,
	MINUS,
	STAR,
	INPUT,
	OUTPUT,
	WHITE,
	COMMENT,
	SEMI,
	EOLN,
	N_TYPES		/* number of different types */
} type_t;

#define is_unique(type) ((type) >= LETTER)

/* Flags on a word. */
#define W_SET		0x01	/* Not undefined, e.g. assigned to. */
#define W_RDONLY	0x02	/* Read only. */
#define W_LOCAL		0x04	/* Local variable, immediate substitution. */
#define W_TEMP		0x08	/* Name of a temporary file, delete on quit. */
#define W_SUFF		0x10	/* Has a suffix set on it. */

void princhar(int c)
/* Print a character, escaped if important to the shell *within* quotes. */
{
	if (strchr("\\'\"<>();~$^&*|{}[]?", c) != nil) fputc('\\', stdout);
	putchar(c);
}

void prinstr(char *s)
/* Print a string, in quotes if the shell might not like it. */
{
	int q= 0;
	char *s2= s;

	while (*s2 != 0)
		if (strchr("~`$^&*()=\\|[]{};'\"<>?", *s2++) != nil) q= 1;

	if (q) fputc('"', stdout);
	while (*s != 0) princhar(*s++);
	if (q) fputc('"', stdout);
}

void prin2(cell_t *p);

void prin1(cell_t *p)
/* Print a cell structure for debugging purposes. */
{
	if (p == nil) {
		printf("(\b(\b()\b)\b)");
		return;
	}

	switch (p->type) {
	case CELL:
		printf("(\b(\b(");
		prin2(p);
		printf(")\b)\b)");
		break;
	case STRING:
		printf("\"\b\"\b\"");
		prin2(p);
		printf("\"\b\"\b\"");
		break;
	case SUBST:
		printf("$\b$\b${%s}", p->subst->name);
		break;
	case LETTER:
		princhar(p->letter);
		break;
	case WORD:
		prinstr(p->name);
		break;
	case EQUALS:
		printf("=\b=\b=");
		break;
	case PLUS:
		printf("+\b+\b+");
		break;
	case MINUS:
		printf("-\b-\b-");
		break;
	case STAR:
		printf("*\b*\b*");
		break;
	case INPUT:
		printf(verbose >= 3 ? "<\b<\b<" : "<");
		break;
	case OUTPUT:
		printf(verbose >= 3 ? ">\b>\b>" : ">");
		break;
	default:
		assert(0);
	}
}

void prin2(cell_t *p)
/* Print a list for debugging purposes. */
{
	while (p != nil && p->type <= STRING) {
		prin1(p->car);

		if (p->type == CELL && p->cdr != nil) fputc(' ', stdout);

		p= p->cdr;
	}
	if (p != nil) prin1(p);		/* Dotted pair? */
}

void prin1n(cell_t *p) { prin1(p); fputc('\n', stdout); }

void prin2n(cell_t *p) { prin2(p); fputc('\n', stdout); }

/* A program is consists of a series of lists at a certain indentation level. */
typedef struct program {
	struct program	*next;
	cell_t		*file;		/* Associated description file. */
	unsigned	indent;		/* Line indentation level. */
	unsigned	lineno;		/* Line number where this is found. */
	cell_t		*line;		/* One line of tokens. */
} program_t;

program_t *pc;		/* Program Counter (what else?) */
program_t *nextpc;	/* Next line to execute. */

cell_t *oldcells;	/* Keep a list of old cells, don't deallocate. */

cell_t *newcell(void)
/* Make a new empty cell. */
{
	cell_t *p;

	if (oldcells != nil) {
		p= oldcells;
		oldcells= p->cdr;
		heap_chunks++;
	} else {
		p= allocate(nil, sizeof(*p));
	}

	p->refc= 0;
	p->type= CELL;
	p->letter= 0;
	p->name= nil;
	p->car= nil;
	p->cdr= nil;
	return p;
}

#define N_CHARS		(1 + (unsigned char) -1)
#define HASHDENSE	0x400

cell_t *oblist[HASHDENSE + N_CHARS + N_TYPES];

unsigned hashfun(cell_t *p)
/* Use a blender on a cell. */
{
	unsigned h;
	char *name;

	switch (p->type) {
	case WORD:
		h= 0;
		name= p->name;
		while (*name != 0) h= (h * 0x1111) + *name++;
		return h % HASHDENSE;
	case LETTER:
		return HASHDENSE + p->letter;
	default:
		return HASHDENSE + N_CHARS + p->type;
	}
}

cell_t *search(cell_t *p, cell_t ***hook)
/* Search for *p, return the one found.  *hook may be used to insert or
 * delete.
 */
{
	cell_t *sp;

	sp= *(*hook= &oblist[hashfun(p)]);

	if (p->type == WORD) {
		/* More than one name per hash slot. */
		int cmp= 0;

		while (sp != nil && (cmp= strcmp(p->name, sp->name)) > 0)
			sp= *(*hook= &sp->hash);

		if (cmp != 0) sp= nil;
	}
	return sp;
}

void dec(cell_t *p)
/* Decrease the number of references to p, if zero delete and recurse. */
{
	if (p == nil || --p->refc > 0) return;

	if (is_unique(p->type)) {
		/* Remove p from the oblist. */
		cell_t *o, **hook;

		o= search(p, &hook);

		if (o == p) {
			/* It's there, remove it. */
			*hook= p->hash;
			p->hash= nil;
		}

		if (p->type == WORD && (p->flags & W_TEMP)) {
			/* A filename to remove. */
			if (verbose >= 2) {
				printf("rm -f ");
				prinstr(p->name);
				fputc('\n', stdout);
			}
			if (unlink(p->name) < 0 && errno != ENOENT)
				report(p->name);
		}
	}
	deallocate(p->name);
	dec(p->car);
	dec(p->cdr);
	p->cdr= oldcells;
	oldcells= p;
	heap_chunks--;
}

cell_t *inc(cell_t *p)
/* Increase the number of references to p. */
{
	cell_t *o, **hook;

	if (p == nil) return nil;

	if (++p->refc > 1 || !is_unique(p->type)) return p;

	/* First appearance, put p on the oblist. */
	o= search(p, &hook);

	if (o == nil) {
		/* Not there yet, add it. */
		p->hash= *hook;
		*hook= p;
	} else {
		/* There is another object already there with the same info. */
		o->refc++;
		dec(p);
		p= o;
	}
	return p;
}

cell_t *go(cell_t *p, cell_t *field)
/* Often happening: You've got p, you want p->field. */
{
	field= inc(field);
	dec(p);
	return field;
}

cell_t *cons(type_t type, cell_t *p)
/* P is to be added to a list (or a string). */
{
	cell_t *l= newcell();
	l->type= type;
	l->refc++;
	l->car= p;
	return l;
}

cell_t *append(type_t type, cell_t *p)
/* P is to be appended to a list (or a string). */
{
	return p == nil || p->type == type ? p : cons(type, p);
}

cell_t *findnword(char *name, size_t n)
/* Find the word with the given name of length n. */
{
	cell_t *w= newcell();
	w->type= WORD;
	w->name= allocate(nil, (n+1) * sizeof(*w->name));
	memcpy(w->name, name, n);
	w->name[n]= 0;
	return inc(w);
}

cell_t *findword(char *name)
/* Find the word with the given null-terminated name. */
{
	return findnword(name, strlen(name));
}

void quit(int exstat)
/* Remove all temporary names, then exit. */
{
	cell_t **op, *p, *v, *b;
	size_t chunks;

	/* Remove cycles, like X = X. */
	for (op= oblist; op < oblist + HASHDENSE; op++) {
		p= *op;
		while (p != nil) {
			if (p->value != nil || p->base != nil) {
				v= p->value;
				b= p->base;
				p->value= nil;
				p->base= nil;
				p= *op;
				dec(v);
				dec(b);
			} else {
				p= p->hash;
			}
		}
	}
	chunks= heap_chunks;

	/* Something may remain on an early quit: tempfiles. */
	for (op= oblist; op < oblist + HASHDENSE; op++) {

		while (*op != nil) { (*op)->refc= 1; dec(*op); }
	}

	if (exstat != -1 && chunks > 0) {
		fprintf(stderr,
			"%s: internal fault: %d chunks still on the heap\n",
						program, chunks);
	}
	exit(exstat);
}

void interrupt(int sig)
{
	signal(sig, interrupt);
	if (verbose >= 2) write(1, "# interrupt\n", 12);
	action= 0;
}

int extalnum(int c)
/* Uppercase, lowercase, digit, underscore or anything non-American. */
{
	return isalnum(c) || c == '_' || c >= 0200;
}

char *descr;		/* Name of current description file. */
FILE *dfp;		/* Open description file. */
int dch;		/* Input character. */
unsigned lineno;	/* Line number in file. */
unsigned indent;	/* Indentation level. */

void getdesc(void)
{
	if (dch == EOF) return;

	if (dch == '\n') { lineno++; indent= 0; }

	if ((dch = getc(dfp)) == EOF && ferror(dfp)) fatal(descr);

	if (dch == 0) {
		fprintf(stderr, "%s: %s is a binary file.\n", program, descr);
		quit(-1);
	}
}

#define E_BASH		0x01	/* Escaped by backslash. */
#define E_QUOTE		0x02	/* Escaped by double quote. */
#define E_SIMPLE	0x04	/* More simple characters? */

cell_t *get_token(void)
/* Read one token from the description file. */
{
	int whitetype= 0;
	static int escape= 0;
	cell_t *tok;
	char *name;
	int n, i;

	if (escape & E_SIMPLE) {
		/* More simple characters?  (Note: performance hack.) */
		if (isalnum(dch)) {
			tok= newcell();
			tok->type= LETTER;
			tok->letter= dch;
			getdesc();
			return inc(tok);
		}
		escape&= ~E_SIMPLE;
	}

	/* Gather whitespace. */
	for (;;) {
		if (dch == '\\' && whitetype == 0) {
			getdesc();
			if (isspace(dch)) {
				/* \ whitespace: remove. */
				do {
					getdesc();
					if (dch == '#' && !(escape & E_QUOTE)) {
						/* \ # comment */
						do
							getdesc();
						while (dch != '\n'
								&& dch != EOF);
					}
				} while (isspace(dch));
				continue;
			}
			escape|= E_BASH;	/* Escaped character. */
		}

		if (escape != 0) break;

		if (dch == '#' && (indent == 0 || whitetype != 0)) {
			/* # Comment. */
			do getdesc(); while (dch != '\n' && dch != EOF);
			whitetype= COMMENT;
			break;
		}

		if (!isspace(dch) || dch == '\n' || dch == EOF) break;

		whitetype= WHITE;

		indent++;
		if (dch == '\t') indent= (indent + 7) & ~7;

		getdesc();
	}

	if (dch == EOF) return nil;

	/* Make a token. */
	tok= newcell();

	if (whitetype != 0) {
		tok->type= whitetype;
		return inc(tok);
	}

	if (!(escape & E_BASH) && dch == '"') {
		getdesc();
		if (!(escape & E_QUOTE)) {
			/* Start of a string, signal this with a string cell. */
			escape|= E_QUOTE;
			tok->type= STRING;
			return inc(tok);
		} else {
			/* End of a string, back to normal mode. */
			escape&= ~E_QUOTE;
			deallocate(tok);
			return get_token();
		}
	}

	if (escape & E_BASH
		|| strchr(escape & E_QUOTE ? "$" : "$=()+-*<>;\n", dch) == nil
	) {
		if (dch == '\n') {
			fprintf(stderr,
				"\"%s\", line %u: missing closing quote\n",
				descr, lineno);
			escape&= ~E_QUOTE;
			action= 0;
		}
		if (escape & E_BASH && dch == 'n') dch= '\n';
		escape&= ~E_BASH;

		/* A simple character. */
		tok->type= LETTER;
		tok->letter= dch;
		getdesc();
		escape|= E_SIMPLE;
		return inc(tok);
	}

	if (dch != '$') {
		/* Single character token. */
		switch (dch) {
		case '=':	tok->type= EQUALS;	break;
		case '(':	tok->type= OPEN;	break;
		case ')':	tok->type= CLOSE;	break;
		case '+':	tok->type= PLUS;	break;
		case '-':	tok->type= MINUS;	break;
		case '*':	tok->type= STAR;	break;
		case '<':	tok->type= INPUT;	break;
		case '>':	tok->type= OUTPUT;	break;
		case ';':	tok->type= SEMI;	break;
		case '\n':	tok->type= EOLN;	break;
		}
		getdesc();
		return inc(tok);
	}

	/* Substitution. */
	getdesc();
	if (dch == EOF || isspace(dch)) {
		fprintf(stderr, "\"%s\", line %u: Word expected after '$'\n",
			descr, lineno);
		action= 0;
		deallocate(tok);
		return get_token();
	}

	name= allocate(nil, (n= 16) * sizeof(*name));
	i= 0;

	if (dch == '{' || dch == '('  /* )} */ ) {
		/* $(X), ${X} */
		int lpar= dch;		/* ( */
		int rpar= lpar == '{' ? '}' : ')';

		for (;;) {
			getdesc();
			if (dch == rpar) { getdesc(); break; }
			if (isspace(dch) || dch == EOF) {
				fprintf(stderr,
				"\"%s\", line %u: $%c unmatched, no '%c'\n",
					descr, lineno, lpar, rpar);
				action= 0;
				break;
			}
			name[i++]= dch;
			if (i == n)
				name= allocate(name, (n*= 2) * sizeof(char));
		}
	} else
	if (extalnum(dch)) {
		/* $X */
		do {
			name[i++]= dch;
			if (i == n)