shithub: scc

Info  •  Files  •  Log  •  Branches

Added accept and expected functions

This functions help in order to have a cleaner code. Some internal functions
of decl.c are set as static, because they are not intended for being called
from outside.

--- a/decl.c

+++ b/decl.c

@@ -17,20 +17,16 @@

 #include <stdio.h>	/* TODO: remove this */

-void decl(void);

+static void declarator(void);

-void dirdcl(void)

+static void dirdcl(void)

 {

 	puts("dirdecl");

-	if (yytoken == '(') {

-		gettok();

-		decl();

-		if (yytoken != ')')

-			error("expected ')'");

-		gettok();

-	} else if (yytoken == IDENTIFIER) {

-		gettok();

+	if (accept('(')) {

+		declarator();

+		expect(')');

+	} else if (accept(IDENTIFIER)) {

 		strcpy(symname, yytext);

 		symhash = yyhash;

 	} else {

@@ -38,22 +34,22 @@

 	}

 	for (;;) {

-		switch (yytoken) {

-		case '(':

+		if (accept('(')) {

+			next();

 			pushtype(FTN);

-			if (gettok() == ')')

-				gettok();

+			if (accept(')'))

+				; /* TODO: k&r function */

 			else

 				/* TODO: prototyped function */;

 			continue;

-		case '[':

+		} else if (accept('[')) {

 			pushtype(ARY);

-			if (gettok() == ']')

-				gettok();

+			if (accept(']'))

+				; /* TODO: automatic size array */

 			else

 				/* TODO: specify size of array */;

 			continue;

-		default:

+		} else {

 			printf("leaving dirdcl %c\n", yytoken);

 			return;

 		}

@@ -68,15 +64,15 @@

  *

  */

-struct type *types[][2] = {{T_VOID, NULL},

-			   {T_SCHAR, T_UCHAR},

-			   {T_SHORT, T_USHORT},

-			   {T_INT, T_UINT},

-			   {T_LONG, T_ULONG},

-			   {T_LLONG, T_ULLONG},

-			   {T_FLOAT, NULL},

-			   {T_DOUBLE, NULL},

-			   {T_LDOUBLE, NULL}};

+static struct type *types[][2] = {{T_VOID, NULL},

+				  {T_SCHAR, T_UCHAR},

+				  {T_SHORT, T_USHORT},

+				  {T_INT, T_UINT},

+				  {T_LONG, T_ULONG},

+				  {T_LLONG, T_ULLONG},

+				  {T_FLOAT, NULL},

+				  {T_DOUBLE, NULL},

+				  {T_LDOUBLE, NULL}};

 #define F_VOID    0

 #define F_CHAR    1

@@ -88,7 +84,7 @@

 #define F_DOUBLE  7

 #define F_LDOUBLE 8

-struct type *specifier(void)

+static struct type *specifier(void)

 {

 	static char sign, sclass, tqlf, nt;

 	struct type *t;

@@ -96,8 +92,8 @@

 repeat:

 	t = NULL;

 	tqlf = sign = sclass = 0;

-	for (;;) {

-		switch (gettok()) {

+	for (;; next()) {

+		switch (yytoken) {

 		case TYPEDEF:case EXTERN:case STATIC:case AUTO:case REGISTER:

 			if (sclass != 0)

 				error("Two or more storage specifier");

@@ -187,16 +183,16 @@

 #undef F_LDOUBLE

-void decl(void)

+static void declarator(void)

 {

 	unsigned char qlf[PTRLEVEL_MAX], *bp, *lim;

-	puts("decl");

+	puts("declarator");

 	lim = qlf + PTRLEVEL_MAX;

 	for (bp = qlf; yytoken == '*' && bp != lim; ++bp) {

 		*bp = 0;

 	repeat_qlf:

-		switch (gettok()) {

+		switch (next()) {

 		case CONST:

 			if (!(*bp ^= 1))

 				goto duplicated;

@@ -233,43 +229,34 @@

 	error("duplicated '%s'", yytext);

 }

-

-

-void declaration(void)

+void decl(void)

 {

 	struct type *t, *spec;

-	struct symbol *sym;

-repeat:

 	spec = specifier();

-

-	for (; ; gettok()) {

-		/* TODO: put here savepoint for error recovering */

-		decl();

-		if (yytoken != ',' && yytoken != ';')

-			error("unexpected", yytext);

+	do {

+		declarator();

 		t = decl_type(spec);

-		ptype(t);

+	} while (accept(','));

+	puts("leaving declaration");

+}

-		if (yytoken == ',')

-			continue;

-		else if (yytoken == ';')

-			goto repeat;

+void stmt(void)

+{

+	for (;;) {

+		decl();

+		expect(';');

 	}

+

 }

-

-

-

-#include <stddef.h>

-

-

 int main(int argc, char *argv[])

 {

 	init_lex();

 	open_file(NULL);

-	declaration();

+	next();

+	stmt();

 	return 0;

 }

--- a/lex.c

+++ b/lex.c

@@ -120,7 +120,7 @@

-unsigned char gettok(void)

+unsigned char next(void)

 {

 	static unsigned int c;

 	register unsigned char ch;

@@ -178,6 +178,21 @@

 	return yytoken = ch;

 }

+char accept(unsigned char tok)

+{

+	if (yytoken == tok) {

+		next();

+		return 1;

+	}

+	return 0;

+}

+

+void expect(unsigned char tok)

+{

+	if (yytoken != tok)

+		error("unexpected %s", yytext);

+	next();

+}

 void open_file(const char *file)

 {

--- a/tokens.h

+++ b/tokens.h

@@ -47,6 +47,8 @@

 extern union yyval yyval;

-extern unsigned char gettok(void);

 extern void init_lex(void);

+extern unsigned char next(void);

+extern char accept(unsigned char tok);

+extern void expect(unsigned char tok);

 #endif

--- a/types.c

+++ b/types.c

@@ -40,6 +40,7 @@

 {

 	while (stackp != stack)

 		t = mktype(t, *--stackp);

+	ptype(t);

 	return t;

 }