shithub: scc

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Merge remote-tracking branch 'origin/master'

--- a/cc1/Makefile

+++ b/cc1/Makefile

@@ -12,6 +12,9 @@

 cc1: $(OBJS) ../lib/libcc.a

 	$(CC) $(LDFLAGS) $(OBJS) ../lib/libcc.a -o $@

+cpp: cc1

+	ln -f cc1 cpp

+

 test:

 	cd tests && ./chktest.sh

--- a/cc1/cc1.h

+++ b/cc1/cc1.h

@@ -46,6 +46,10 @@

 	} min;

 };

+struct keyword {

+	char *str;

+	unsigned char token, value;

+};

 struct type {

 	unsigned char op;           /* type builder operator */

@@ -345,9 +349,9 @@

 extern Symbol *install(int ns, Symbol *sym);

 extern Symbol *newsym(int ns);

 extern void pushctx(void), popctx(void);

-extern void ikeywords(void);

-extern void delmacro(Symbol *sym);

+extern void killsym(Symbol *sym);

 extern Symbol *newlabel(void);

+extern void keywords(struct keyword *key, int ns);

 /* stmt.c */

 extern void compound(Symbol *lbreak, Symbol *lcont, Caselist *lswitch);

@@ -396,6 +400,8 @@

 extern bool cpp(void);

 extern bool expand(char *begin, Symbol *sym);

 extern void incdir(char *dir);

+extern void outcpp(void);

+extern Symbol *defmacro(char *s);

 /*

  * Definition of global variables

@@ -407,7 +413,7 @@

 extern int cppoff, disexpand;

 extern unsigned cppctx;

 extern Input *input;

-extern int lexmode, namespace;

+extern int lexmode, namespace, onlycpp;

 extern unsigned curctx;

 extern Symbol *curfun, *zero, *one;

--- a/cc1/cpp.c

+++ b/cc1/cpp.c

@@ -25,10 +25,23 @@

 unsigned cppctx;

 int disexpand;

-static Symbol *

+Symbol *

 defmacro(char *s)

 {

-	return install(NS_CPP, lookup(NS_CPP, s));

+	char *p, *q;

+	Symbol *sym;

+	size_t len;

+

+	if ((p = strchr(s, '=')) != NULL) {

+		*p++='\0';

+		len = strlen(p);

+		q = xmalloc(len+4);

+		sprintf(q, "-1#%s", p);

+		p = q;

+	}

+	sym = install(NS_CPP, lookup(NS_CPP, s));

+	sym->u.s = p;

+	return sym;

 }

 void

@@ -37,12 +50,27 @@

 	static char sdate[17], stime[14];

 	struct tm *tm;

 	time_t t;

-	char **bp, *list[] = {

+	static char **bp, *list[] = {

 		"__STDC__",

 		"__STDC_HOSTED__",

 		"__SCC__",

 		NULL

 	};

+	static struct keyword keys[] = {

+		{"define", DEFINE, DEFINE},

+		{"include", INCLUDE, INCLUDE},

+		{"line", LINE, LINE},

+		{"ifdef", IFDEF, IFDEF},

+		{"if", IF, IF},

+		{"elif", ELIF, ELIF},

+		{"else", ELSE, ELSE},

+		{"ifndef", IFNDEF, IFNDEF},

+		{"endif", ENDIF, ENDIF},

+		{"undef", UNDEF, UNDEF},

+		{"pragma", PRAGMA, PRAGMA},

+		{"error", ERROR, ERROR},

+		{NULL, 0, 0}

+	};

 	t = time(NULL);

 	tm = localtime(&t);

@@ -57,6 +85,7 @@

 	for (bp = list; *bp; ++bp)

 		defmacro(*bp)->u.s = "-1#1";

+	keywords(keys, NS_CPPCLAUSES);

 }

 static void

@@ -145,21 +174,39 @@

 	return 1;

 }

+/* FIXME: characters in the definition break the macro definition */

 static size_t

 copymacro(char *buffer, char *s, size_t bufsiz, char *arglist[])

 {

-	char prevc, c, *arg, *bp = buffer;

+	char prevc, c, *p, *arg, *bp = buffer;

+	size_t size;

 	for (prevc = '\0'; c = *s; prevc = c, ++s) {

 		if (c != '@') {

-			if (c == '#')

+			switch (c) {

+			case '$':

+				while (bp[-1] == ' ')

+					--bp, ++bufsiz;

+				while (s[1] == ' ')

+					++s;

+			case '#':

 				continue;

+			case '\"':

+				for (p = s; *++s != '"'; )

+					/* nothing */;

+				size = s - p + 1;

+				if (size > bufsiz)

+					goto expansion_too_long;

+				memcpy(bp, p, size);

+				bufsiz -= size;

+				bp += size;

+				continue;

+			// case '\'';

+			}

 			if (bufsiz-- == 0)

 				goto expansion_too_long;

 			*bp++ = c;

 		} else {

-			size_t size;

-

 			if (prevc == '#')

 				bufsiz -= 2;

 			arg = arglist[atoi(++s)];

@@ -194,7 +241,9 @@

 	char *arglist[NR_MACROARG], arguments[INPUTSIZ], buffer[BUFSIZE];

 	macroname = sym->name;

-	if (!(sym->flags & ISDECLARED)) {

+	if ((sym->flags & ISDECLARED) == 0) {

+		if (namespace == NS_CPP && !strcmp(sym->name, "defined"))

+			return 0;  /* we found a 'defined in an #if */

 		/*

 		 * This case happens in #if were macro not defined must

 		 * be expanded to 0

@@ -216,12 +265,12 @@

 	if (!parsepars(arguments, arglist, atoi(s)))

 		return 0;

 	for (n = 0; n < atoi(s); ++n)

-		DBG("MACRO par%d:%s\n", n, arglist[n]);

+		DBG("MACRO par%d:%s", n, arglist[n]);

 	elen = copymacro(buffer, s+3, INPUTSIZ-1, arglist);

 substitute:

-	DBG("MACRO '%s' expanded to :'%s'\n", macroname, buffer);

+	DBG("MACRO '%s' expanded to :'%s'", macroname, buffer);

 	rlen = strlen(input->p);      /* rigth length */

 	llen = begin - input->line;   /* left length */

 	ilen = input->p - begin;      /* invocation length */

@@ -241,7 +290,7 @@

 	input->p = input->begin = begin;

 	if (!(sym->flags & ISDECLARED))

-		delmacro(sym);

+		killsym(sym);

 	return 1;

 }

@@ -285,6 +334,11 @@

 	size_t len;

 	int prevc = 0, ispar;

+	if (yytoken == '$') {

+		cpperror("'##' cannot appear at either end of a macro expansion");

+		return 0;

+	}

+

 	for (;;) {

 		ispar = 0;

 		if (yytoken == IDEN && nargs >= 0) {

@@ -308,10 +362,15 @@

 			cpperror("too long macro");

 			return 0;

 		}

-		memcpy(bp, yytext, len);

-		bp += len;

-		bufsiz -= len;

-		if ((prevc = yytoken) != '#')

+		if (yytoken == '$') {

+			*bp++ = '$';

+			 --bufsiz;

+		} else {

+			memcpy(bp, yytext, len);

+			bp += len;

+			bufsiz -= len;

+		}

+		if ((prevc  = yytoken) != '#')

 			*bp++ = ' ';

 		next();

 	}

@@ -342,7 +401,7 @@

 		free(sym->u.s);

 	} else {

 		sym = install(NS_CPP, sym);

-		sym->flags |= ISDECLARED;

+		sym->flags |= ISDECLARED|ISSTRING;

 	}

 	namespace = NS_IDEN;       /* Avoid polution in NS_CPP */

@@ -353,11 +412,11 @@

 	if (!getdefs(args, n, buff+3, LINESIZ-3))

 		goto delete;

 	sym->u.s = xstrdup(buff);

-	DBG("MACRO '%s' defined as '%s'\n", sym->name, buff);

+	DBG("MACRO '%s' defined as '%s'", sym->name, buff);

 	return;

 delete:

-	delmacro(sym);

+	killsym(sym);

 }

 void

@@ -531,7 +590,7 @@

 		next();

 		status = (sym->flags & ISDECLARED) != 0;

 		if (!status)

-			delmacro(sym);

+			killsym(sym);

 	} else {

 		/* TODO: catch recovery here */

 		if ((expr = iconstexpr()) == NULL) {

@@ -589,6 +648,7 @@

 elif(void)

 {

 	elseclause();

+	--cppctx;

 	cppif();

 }

@@ -614,7 +674,7 @@

 		error("no macro name given in #undef directive");

 		return;

 	}

-	delmacro(yylval.sym);

+	killsym(yylval.sym);

 	next();

 }

@@ -670,3 +730,47 @@

 	return 1;

 }

+

+void

+outcpp(void)

+{

+	char c, *s, *t;

+

+	for (next(); yytoken != EOFTOK; next()) {

+		if (yytoken != CONSTANT || *yytext != '"') {

+			printf("%s ", yytext);

+			continue;

+		}

+		for (s = yylval.sym->u.s; c = *s; ++s) {

+			switch (c) {

+			case '\n':

+				t = "\\n";

+				goto print_str;

+			case '\v':

+				t = "\\v";

+				goto print_str;

+			case '\b':

+				t = "\\b";

+				goto print_str;

+			case '\t':

+				t = "\\t";

+				goto print_str;

+			case '\a':

+				t = "\\a";

+			print_str:

+				fputs(t, stdout);

+				break;

+			case '\\':

+				putchar('\\');

+			default:

+				if (!isprint(c))

+					printf("\\x%x", c);

+				else

+					putchar(c);

+				break;

+			}

+		}

+	}

+	putchar('\n');

+}

+

--- a/cc1/expr.c

+++ b/cc1/expr.c

@@ -496,6 +496,32 @@

 	}

 }

+static Symbol *

+notdefined(Symbol *sym)

+{

+	int isdef;

+

+	if (namespace == NS_CPP && !strcmp(sym->name, "defined")) {

+		disexpand = 1;

+		next();

+		expect('(');

+		sym = yylval.sym;

+		expect(IDEN);

+		expect(')');

+

+		isdef = (sym->flags & ISDECLARED) != 0;

+		sym = newsym(NS_IDEN);

+		sym->type = inttype;

+		sym->flags |= ISCONSTANT;

+		sym->u.i = isdef;

+		disexpand = 0;

+		return sym;

+	}

+	errorp("'%s' undeclared", yytext);

+	sym->type = inttype;

+	return install(sym->ns, yylval.sym);

+}

+

 /*************************************************************

  * grammar functions                                         *

  *************************************************************/

@@ -505,17 +531,18 @@

 	Node *np;

 	Symbol *sym;

+	sym = yylval.sym;

 	switch (yytoken) {

 	case CONSTANT:

-		np = constnode(yylval.sym);

+		np = constnode(sym);

 		next();

 		break;

 	case IDEN:

-		sym = yylval.sym;

-		if ((sym->flags & ISDECLARED) == 0) {

-			errorp("'%s' undeclared", yytext);

-			sym->type = inttype;

-			install(sym->ns, yylval.sym);

+		if ((sym->flags & ISDECLARED) == 0)

+			sym = notdefined(sym);

+		if (sym->flags & ISCONSTANT) {

+			np = constnode(sym);

+			break;

 		}

 		sym->flags |= ISUSED;

 		np = varnode(sym);

@@ -566,8 +593,6 @@

 					arg = convert(arg, doubletype, 1);

 				break;

 			}

-			if (arg->type->op == INT)

-				arg = promote(arg);

 			par = node(OPAR, arg->type, par, arg);

 			continue;

 		}

--- a/cc1/fold.c

+++ b/cc1/fold.c

@@ -480,6 +480,11 @@

 	return NULL;

 }

+/*

+ * TODO: transform simplify in a recursivity

+ * function, because we are losing optimization

+ * chances

+ */

 Node *

 simplify(int op, Type *tp, Node *lp, Node *rp)

 {

--- a/cc1/lex.c

+++ b/cc1/lex.c

@@ -39,6 +39,44 @@

 void

 ilex(char *fname)

 {

+	static struct keyword keys[] = {

+		{"auto", SCLASS, AUTO},

+		{"break", BREAK, BREAK},

+		{"_Bool", TYPE, BOOL},

+		{"case", CASE, CASE},

+		{"char", TYPE, CHAR},

+		{"const", TQUALIFIER, CONST},

+		{"continue", CONTINUE, CONTINUE},

+		{"default", DEFAULT, DEFAULT},

+		{"do", DO, DO},

+		{"double", TYPE, DOUBLE},

+		{"else", ELSE, ELSE},

+		{"enum", TYPE, ENUM},

+		{"extern", SCLASS, EXTERN},

+		{"float", TYPE, FLOAT},

+		{"for", FOR, FOR},

+		{"goto", GOTO, GOTO},

+		{"if", IF, IF},

+		{"inline", TQUALIFIER, INLINE},

+		{"int", TYPE, INT},

+		{"long", TYPE, LONG},

+		{"register", SCLASS, REGISTER},

+		{"restrict", TQUALIFIER, RESTRICT},

+		{"return", RETURN, RETURN},

+		{"short", TYPE, SHORT},

+		{"signed", TYPE, SIGNED},

+		{"sizeof", SIZEOF, SIZEOF},

+		{"static", SCLASS, STATIC},

+		{"struct", TYPE, STRUCT},

+		{"switch", SWITCH, SWITCH},

+		{"typedef", SCLASS, TYPEDEF},

+		{"union", TYPE, UNION},

+		{"unsigned", TYPE, UNSIGNED},

+		{"void", TYPE, VOID},

+		{"volatile", TQUALIFIER, VOLATILE},

+		{"while", WHILE, WHILE},

+		{NULL, 0, 0},

+	};

 	FILE *fp;

 	if (!fname) {

@@ -52,6 +90,7 @@

 	}

 	allocinput(fname, fp);

 	*input->begin = '\0';

+	keywords(keys, NS_KEYWORD);

 }

 bool

@@ -176,6 +215,10 @@

 bool

 moreinput(void)

 {

+	static char file[FILENAME_MAX];

+	static unsigned nline;

+	char *s;

+

 repeat:

 	if (!readline())

 		return 0;

@@ -187,6 +230,19 @@

 		goto repeat;

 	}

+	if (onlycpp) {

+		putchar('\n');

+		if (strcmp(file, input->fname)) {

+			strcpy(file, input->fname);

+			s = "#line %u %s\n";

+		} else if (nline+1 != input->nline) {

+			s = "#line %u\n";

+		} else {

+			s = "";

+		}

+		nline = input->nline;

+		printf(s, nline, file);

+	}

 	input->begin = input->p;

 	return 1;

 }

@@ -525,6 +581,7 @@

 	case '*': t = follow('=', MUL_EQ, '*'); break;

 	case '/': t = follow('=', DIV_EQ, '/'); break;

 	case '!': t = follow('=', NE, '!'); break;

+	case '#': t = follow('#', '$', '#'); break;

 	case '-': t = minus(); break;

 	case '+': t = plus(); break;

 	case '.': t = dot(); break;

@@ -576,7 +633,7 @@

 		yytoken = operator();

 exit:

-	DBG("TOKEN %s\n", yytext);

+	DBG("TOKEN %s", yytext);

 	return yytoken;

 }

--- a/cc1/main.c

+++ b/cc1/main.c

@@ -12,8 +12,8 @@

 int warnings;

 jmp_buf recover;

-static char *output;

-static int onlycpp;

+static char *output, *arg0;

+int onlycpp;

 static void

 clean(void)

@@ -27,7 +27,9 @@

 static void

 usage(void)

 {

-	fputs("usage: cc1 [-w] [-o output] [input]\n", stderr);

+	fprintf(stderr,

+	        "usage: %s [-E] [-Dmacro[=value]] [-Idir] [-w] [-d] [-o output] [input]\n",

+	        arg0);

 	exit(1);

 }

@@ -38,6 +40,10 @@

 	atexit(clean);

+	arg0 = (cp = strrchr(*argv, '/')) ? cp+1 : *argv;

+	if (!strcmp(arg0, "cpp"))

+		onlycpp = 1;

+

 	for (;;) {

 	nextiter:

 		--argc, ++argv;

@@ -51,6 +57,12 @@

 			case 'E':

 				onlycpp = 1;

 				break;

+			case 'D':

+				defmacro(cp+1);

+				goto nextiter;

+			case 'd':

+				DBGON();

+				break;

 			case 'I':

 				incdir(cp+1);

 				goto nextiter;

@@ -72,12 +84,10 @@

 		usage();

 	icpp();

-	ikeywords();

 	ilex(*argv);

 	if (onlycpp) {

-		for (next(); yytoken != EOFTOK; next())

-			printf("%s ", yytext);

+		outcpp();

 	} else {

 		for (next(); yytoken != EOFTOK; decl())

 			/* nothing */;

--- a/cc1/symbol.c

+++ b/cc1/symbol.c

@@ -76,7 +76,7 @@

 		error("too much nested blocks");

 }

-static void

+void

 killsym(Symbol *sym)

 {

 	short f;

@@ -87,14 +87,14 @@

 		free(sym->u.s);

 	if (sym->ns == NS_TAG)

 		sym->type->defined = 0;

-	if ((name = sym->name) != NULL) {

-		unlinkhash(sym);

+	unlinkhash(sym);

+	if ((name = sym->name) != NULL && sym->ns != NS_CPP) {

 		if ((f & (ISUSED|ISGLOBAL|ISDECLARED)) == ISDECLARED)

 			warn("'%s' defined but not used", name);

 		if ((f & ISDEFINED) == 0 && sym->ns == NS_LABEL)

 			errorp("label '%s' is not defined", name);

-		free(name);

 	}

+	free(name);

 	free(sym);

 }

@@ -168,7 +168,6 @@

 {

 	Symbol *p, *prev;

-	sym->flags |= ISDECLARED;

 	switch (sym->ns) {

 	case NS_CPP:

 		return sym;

@@ -198,7 +197,6 @@

 	Symbol **h, *p, *prev;

 	h = &htab[hash(sym->name)];

-

 	for (prev = p = *h; p; prev = p, p = p->hash) {

 		if (p->ctx <= sym->ctx)

 			break;

@@ -214,6 +212,7 @@

 	if (sym->ns != NS_CPP)

 		sym->id = newid();

+	sym->flags |= ISDECLARED;

 	return linksym(sym);

 }

@@ -220,10 +219,7 @@

 Symbol *

 newsym(int ns)

 {

-	Symbol *sym;

-

-	sym = linksym(allocsym(ns, NULL));

-	return sym;

+	return linksym(allocsym(ns, NULL));

 }

 Symbol *

@@ -253,15 +249,6 @@

 	return allocsym(ns, name);

 }

-void

-delmacro(Symbol *sym)

-{

-	unlinkhash(sym);

-	free(sym->name);

-	free(sym->u.s);

-	free(sym);

-}

-

 Symbol *

 nextsym(Symbol *sym, int ns)

 {

@@ -296,77 +283,14 @@

 }

 void

-ikeywords(void)

+keywords(struct keyword *key, int ns)

 {

-	static struct {

-		char *str;

-		unsigned char token, value;

-	} *bp, keywords[] = {

-		{"auto", SCLASS, AUTO},

-		{"break", BREAK, BREAK},

-		{"_Bool", TYPE, BOOL},

-		{"case", CASE, CASE},

-		{"char", TYPE, CHAR},

-		{"const", TQUALIFIER, CONST},

-		{"continue", CONTINUE, CONTINUE},

-		{"default", DEFAULT, DEFAULT},

-		{"do", DO, DO},

-		{"double", TYPE, DOUBLE},

-		{"else", ELSE, ELSE},

-		{"enum", TYPE, ENUM},

-		{"extern", SCLASS, EXTERN},

-		{"float", TYPE, FLOAT},

-		{"for", FOR, FOR},

-		{"goto", GOTO, GOTO},

-		{"if", IF, IF},

-		{"inline", TQUALIFIER, INLINE},

-		{"int", TYPE, INT},

-		{"long", TYPE, LONG},

-		{"register", SCLASS, REGISTER},

-		{"restrict", TQUALIFIER, RESTRICT},

-		{"return", RETURN, RETURN},

-		{"short", TYPE, SHORT},

-		{"signed", TYPE, SIGNED},

-		{"sizeof", SIZEOF, SIZEOF},

-		{"static", SCLASS, STATIC},

-		{"struct", TYPE, STRUCT},

-		{"switch", SWITCH, SWITCH},

-		{"typedef", SCLASS, TYPEDEF},

-		{"union", TYPE, UNION},

-		{"unsigned", TYPE, UNSIGNED},

-		{"void", TYPE, VOID},

-		{"volatile", TQUALIFIER, VOLATILE},

-		{"while", WHILE, WHILE},

-		{NULL, 0, 0},

-	}, cppclauses[] = {

-		{"define", DEFINE, DEFINE},

-		{"include", INCLUDE, INCLUDE},

-		{"line", LINE, LINE},

-		{"ifdef", IFDEF, IFDEF},

-		{"if", IF, IF},

-		{"elif", ELIF, ELIF},

-		{"else", ELSE, ELSE},

-		{"ifndef", IFNDEF, IFNDEF},

-		{"endif", ENDIF, ENDIF},

-		{"undef", UNDEF, UNDEF},

-		{"pragma", PRAGMA, PRAGMA},

-		{"error", ERROR, ERROR},

-		{NULL, 0, 0}

-	}, *list[] = {

-		keywords,

-		cppclauses,

-		NULL

-	}, **lp;

 	Symbol *sym;

-	int ns = NS_KEYWORD;

-	for (lp = list; *lp; ++lp) {

-		for (bp = *lp; bp->str; ++bp) {

-			sym = linkhash(allocsym(ns, bp->str));

-			sym->token = bp->token;

-			sym->u.token = bp->value;

-		}

-		ns = NS_CPPCLAUSES;

+	for ( ; key->str; ++key) {

+		sym = linkhash(allocsym(ns, key->str));

+		sym->token = key->token;

+		sym->u.token = key->value;

 	}

 	/*

 	 * Remove all the predefined symbols from * the symbol list. It

--- /dev/null

+++ b/cc1/tests/test031.c

@@ -1,0 +1,33 @@

+

+/*

+name: TEST031

+description: Test concatenation in preprocessor

+output:

+F5	I

+G6	F5	main

+{

+\

+A7	I	foo

+A8	I	bar

+A9	I	foobar

+	A9	A7	A8	+I	:I

+	A9	A7	A8	+I	:I

+	r	#I0

+}

+*/

+

+#define CAT(x,y) x ## y

+#define XCAT(x,y) CAT(x,y)

+#define FOO foo

+#define BAR bar

+

+int

+main(void)

+{

+	int foo, bar, foobar;

+

+	CAT(foo,bar) = foo + bar;

+	XCAT(FOO,BAR) = foo + bar;

+	return 0;

+}

+

--- /dev/null

+++ b/cc1/tests/test032.c

@@ -1,0 +1,25 @@

+

+/*

+name: TEST032

+description: test special characters @ and $ in macro definitions

+output:

+F3	I

+G4	F3	main

+{

+\

+A6	P	p

+	A6	"54686973206973206120737472696E672024206F722023206F72202323616E64206974206973206F6B2021	'P	:P

+	r	A6	#P0	!I

+}

+*/

+

+#define M1(x) "This is a string $ or # or ##" ## #x

+

+int

+main(void)

+{

+	char *p = M1(and it is ok!);

+

+	return p != 0;

+}

+

--- /dev/null

+++ b/cc1/tests/test033.c

@@ -1,0 +1,17 @@

+/*

+name: TEST033

+description: test for #if defined()

+output:

+G1	I	c

+*/

+

+#if defined(FOO)

+int a;

+#elif !defined(FOO) && defined(BAR)

+int b;

+#elif !defined(FOO) && !defined(BAR)

+int c;

+#else

+int d;

+#endif

+

--- a/cc1/tests/update.sh

+++ b/cc1/tests/update.sh

@@ -1,8 +1,26 @@

 #!/bin/sh

+update()

+{

+	(echo '/^output/+;/^\*\//-c'

+	../cc1 -I./ -w $1 2>&1

+	printf ".\nw\n") | ed -s $1

+}

+

+

+case $# in

+1)

+	update $1

+	exit

+	;;

+*)

+	echo "usage: update.sh [test]" >&2

+	exit 1

+	;;

+esac

+

+

 for i in *.c

 do

-	(echo '/^output/+;/^\*\//-c'

-	../cc1 -w $i 2>&1

-	printf ".\nw\n") | ed -s $i

+	update $i

 done

--- a/inc/cc.h

+++ b/inc/cc.h

@@ -8,9 +8,12 @@

 #endif

 #ifndef NDEBUG

-#define DBG(...) fprintf(stderr, __VA_ARGS__)

+extern int debug;

+#define DBG(fmt, ...) dbg(fmt, __VA_ARGS__)

+#define DBGON() (debug = 1)

 #else

 #define DBG(...)

+#define DBGON()

 #endif

 #define L_INT8      'C'

@@ -39,8 +42,8 @@

 #define L_EXTERN    'X'

 extern void die(const char *fmt, ...);

+extern void dbg(const char *fmt, ...);

 extern void *xmalloc(size_t size);

 extern void *xcalloc(size_t nmemb, size_t size);

 extern char *xstrdup(const char *s);

 extern void *xrealloc(void *buff, register size_t size);

-

--- a/lib/Makefile

+++ b/lib/Makefile

@@ -1,6 +1,6 @@

 include ../config.mk

-OBJS = die.o xcalloc.o xmalloc.o xrealloc.o xstrdup.o

+OBJS = die.o xcalloc.o xmalloc.o xrealloc.o xstrdup.o debug.o

 all: libcc.a

--- /dev/null

+++ b/lib/debug.c

@@ -1,0 +1,20 @@

+

+#include <stdarg.h>

+#include <stdio.h>

+

+#include "../inc/cc.h"

+

+int debug;

+

+void

+dbg(const char *fmt, ...)

+{

+	if (!debug)

+		return;

+	va_list va;

+	va_start(va, fmt);

+	vfprintf(stderr, fmt, va);

+	putc('\n', stderr);

+	va_end(va);

+	return;

+}