lint.c

unix v7是最后一个广泛发布的研究型UNIX版本

# include "mfile1"

# include "lmanifest"

# include <ctype.h>

# define VAL 0
# define EFF 1

/* these are appropriate for the -p flag */
int  SZCHAR = 8;
int  SZINT = 16;
int  SZFLOAT = 32;
int  SZDOUBLE = 64;
int  SZLONG = 32;
int  SZSHORT = 16;
int SZPOINT = 16;
int ALCHAR = 8;
int ALINT = 16;
int ALFLOAT = 32;
int ALDOUBLE = 64;
int ALLONG = 32;
int ALSHORT = 16;
int ALPOINT = 16;
int ALSTRUCT = 16;

int vflag = 1;  /* tell about unused argments */
int xflag = 0;  /* tell about unused externals */
int argflag = 0;  /* used to turn off complaints about arguments */
int libflag = 0;  /* used to generate library descriptions */
int vaflag = -1;  /* used to signal functions with a variable number of args */
int aflag = 0;  /* used th check precision of assignments */

char *flabel = "xxx";

# define LNAMES 100

struct lnm {
	short lid, flgs;
	}  lnames[LNAMES], *lnp;

contx( p, down, pl, pr ) register NODE *p; register *pl, *pr; {

	*pl = *pr = VAL;
	switch( p->op ){

	case ANDAND:
	case OROR:
	case QUEST:
		*pr = down;
		break;

	case SCONV:
	case PCONV:
	case COLON:
		*pr = *pl = down;
		break;

	case COMOP:
		*pl = EFF;
		*pr = down;

	case FORCE:
	case INIT:
	case UNARY CALL:
	case STCALL:
	case UNARY STCALL:
	case CALL:
	case UNARY FORTCALL:
	case FORTCALL:
	case CBRANCH:
		break;

	default:
		if( asgop(p->op) ) break;
		if( p->op == UNARY MUL && ( p->type == STRTY || p->type == UNIONTY) ) {
			break;  /* the compiler does this... */
			}
		if( down == EFF && hflag ) werror( "null effect" );

		}
	}

ecode( p ) NODE *p; {
	/* compile code for p */

	fwalk( p, contx, EFF );
	lnp = lnames;
	lprt( p, EFF, 0 );
	}

ejobcode( flag ){
	/* called after processing each job */
	/* flag is nonzero if errors were detected */
	register k;
	register struct symtab *p;

	for( p=stab; p< &stab[SYMTSZ]; ++p ){

		if( p->stype != TNULL ) {

			if( p->stype == STRTY || p->stype == UNIONTY ){
				if( dimtab[p->sizoff+1] < 0 ){ /* never defined */
					if( hflag ) werror( "struct/union %.7s never defined", p->sname );
					}
				}

			switch( p->sclass ){
			
			case STATIC:
				if( p->suse > 0 ){
					k = lineno;
					lineno = p->suse;
					uerror( "static variable %s unused",
						p->sname );
					lineno = k;
					break;
					}

			case EXTERN:
			case USTATIC:
				/* with the xflag, worry about externs not used */
				/* the filename may be wrong here... */
				if( xflag && p->suse >= 0 && !libflag ){
					printf( "%.7s\t%03d\t%o\t%d\t", p->sname, LDX, p->stype, 0 );
					/* we don't really know the file number; we know only the line 
						number, so we put only that out */
					printf( "\"???\"\t%d\t%s\n", p->suse, flabel );
					}
			
			case EXTDEF:
				if( p->suse < 0 ){  /* used */
					printf( "%.7s\t%03d\t%o\t%d\t", exname(p->sname), LUM, p->stype, 0 );
					fident( -p->suse );
					}
				break;
				}
			
			}

		}
	exit( 0 );
	}

fident( line ){ /* like ident, but lineno = line */
	register temp;
	temp = lineno;
	lineno = line;
	ident();
	lineno = temp;
	}

ident(){ /* write out file and line identification  */
	printf( "%s\t%d\t%s\n", ftitle, lineno, flabel );
	}

bfcode( a, n ) int a[]; {
	/* code for the beginning of a function; a is an array of
		indices in stab for the arguments; n is the number */
	/* this must also set retlab */
	register i;
	register struct symtab *cfp;
	register unsigned t;

	retlab = 1;
	cfp = &stab[curftn];

	/* if variable number of arguments, only print the ones which will be checked */
	if( vaflag > 0 ){
		if( n < vaflag ) werror( "declare the VARARGS arguments you want checked!" );
		else n = vaflag;
		}
	printf( "%.7s\t%03d\t%o\t%d\t", exname(cfp->sname), libflag?LIB:LDI,
		cfp->stype, vaflag>=0?-n:n );
	vaflag = -1;

	for( i=0; i<n; ++i ) {
		switch( t = stab[a[i]].stype ){

		case ULONG:
			break;

		case CHAR:
		case SHORT:
			t = INT;
			break;

		case UCHAR:
		case USHORT:
		case UNSIGNED:
			t = UNSIGNED;
			break;

			}

		printf( "%o\t", t );
		}
	ident();
	}

ctargs( p ) NODE *p; {
	/* count arguments; p points to at least one */
	/* the arguemnts are a tower of commasto the left */
	register c;
	c = 1; /* count the rhs */
	while( p->op == CM ){
		++c;
		p = p->left;
		}
	return( c );
	}

lpta( p ) NODE *p; {
	TWORD t;

	if( p->op == CM ){
		lpta( p->left );
		p = p->right;
		}
	switch( t = p->type ){

		case CHAR:
		case SHORT:
			t = INT;
		case LONG:
		case ULONG:
		case INT:
		case UNSIGNED:
			break;

		case UCHAR:
		case USHORT:
			t = UNSIGNED;
			break;

		case FLOAT:
			printf( "%o\t", DOUBLE );
			return;

		default:
			printf( "%o\t", p->type );
			return;
		}

	if( p->op == ICON ) printf( "%o<1\t", t );
	else printf( "%o\t", t );
	}

# define VALSET 1
# define VALUSED 2
# define VALASGOP 4
# define VALADDR 8

lprt( p, down, uses ) register NODE *p; {
	register struct symtab *q;
	register id;
	register acount;
	register down1, down2;
	register use1, use2;
	register struct lnm *np1, *np2;

	/* first, set variables which are set... */

	use1 = use2 = VALUSED;
	if( p->op == ASSIGN ) use1 = VALSET;
	else if( p->op == UNARY AND ) use1 = VALADDR;
	else if( asgop( p->op ) ){ /* =ops */
		use1 = VALUSED|VALSET;
		if( down == EFF ) use1 |= VALASGOP;
		}


	/* print the lines for lint */

	down2 = down1 = VAL;
	acount = 0;

	switch( p->op ){

	case EQ:
	case NE:
	case GT:
	case GE:
	case LT:
	case LE:
		if( p->left->type == CHAR && p->right->op==ICON && p->right->lval < 0 ){
			werror( "nonportable character comparison" );
			}
		if( (p->op==EQ || p->op==NE ) && ISUNSIGNED(p->left->type) && p->right->op == ICON ){
			if( p->right->lval < 0 && p->right->rval == NONAME && !ISUNSIGNED(p->right->type) ){
				werror( "comparison of unsigned with negative constant" );
				}
			}
		break;

	case UGE:
	case ULT:
		if( p->right->op == ICON && p->right->lval == 0 && p->right->rval == NONAME ){
			werror( "unsigned comparison with 0?" );
			break;
			}
	case UGT:
	case ULE:
		if( p->right->op == ICON && p->right->lval <= 0 && !ISUNSIGNED(p->right->type) && p->right->rval == NONAME ){
			werror( "degenerate unsigned comparison" );
			}
		break;

	case COMOP:
		down1 = EFF;

	case ANDAND:
	case OROR:
	case QUEST:
		down2 = down;
		/* go recursively left, then right  */
		np1 = lnp;
		lprt( p->left, down1, use1 );
		np2 = lnp;
		lprt( p->right, down2, use2 );
		lmerge( np1, np2, 0 );
		return;

	case SCONV:
	case PCONV:
	case COLON:
		down1 = down2 = down;
		break;

	case CALL:
	case STCALL:
	case FORTCALL:
		acount = ctargs( p->right );
	case UNARY CALL:
	case UNARY STCALL:
	case UNARY FORTCALL:
		if( p->left->op == ICON && (id=p->left->rval) != NONAME ){ /* used to be &name */
			printf( "%.7s\t%03d\t%o\t%d\t",
				exname(stab[id].sname),
				down==EFF ? LUE : LUV,
				DECREF(p->left->type), acount );
			if( acount ) lpta( p->right );
			ident();
			}
		break;

	case ICON:
		/* look for &name case */
		if( (id = p->rval) >= 0 && id != NONAME ){
			q = &stab[id];
			q->sflags |= (SREF|SSET);
			}
		return;

	case NAME:
		if( (id = p->rval) >= 0 && id != NONAME ){
			q = &stab[id];
			if( (uses&VALUSED) && !(q->sflags&SSET) ){
				if( q->sclass == AUTO || q->sclass == REGISTER ){
					if( !ISARY(q->stype ) && !ISFTN(q->stype) && q->stype!=STRTY ){
						werror( "%.7s may be used before set", q->sname );
						q->sflags |= SSET;
						}
					}
				}
			if( uses & VALASGOP ) break;  /* not a real use */
			if( uses & VALSET ) q->sflags |= SSET;
			if( uses & VALUSED ) q->sflags |= SREF;
			if( uses & VALADDR ) q->sflags |= (SREF|SSET);
			if( p->lval == 0 ){
				lnp->lid = id;
				lnp->flgs = (uses&VALADDR)?0:((uses&VALSET)?VALSET:VALUSED);
				if( ++lnp >= &lnames[LNAMES] ) --lnp;
				}
			}
		return;

		}

	/* recurse, going down the right side first if we can */

	switch( optype(p->op) ){

	case BITYPE:
		np1 = lnp;
		lprt( p->right, down2, use2 );
	case UTYPE:
		np2 = lnp;
		lprt( p->left, down1, use1 );
		}

	if( optype(p->op) == BITYPE ){
		if( p->op == ASSIGN && p->left->op == NAME ){ /* special case for a =  .. a .. */
			lmerge( np1, np2, 0 );
			}
		else lmerge( np1, np2, p->op != COLON );
		/* look for assignments to fields, and complain */