lint.c

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· C语言 代码 · 共 831 行 · 第 1/2 页

#ifndef lint
static char sccsid[] = "@(#)lint.c	1.5	(Berkeley)	3/30/83";
#endif lint

# include "mfile1"

# include "lmanifest"

# include <ctype.h>

# define VAL 0
# define EFF 1

extern int ddebug, idebug, bdebug, tdebug, edebug, xdebug;	/* CXREF */

int blocknos[20];	/* CXREF */
int blockptr = 0;	/* CXREF */
int nextblock = 1;	/* CXREF */

/* 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 to check precision of assignments */
int zflag = 0;  /* no 'structure never defined' error */
int Cflag = 0;  /* filter out certain output, for generating libraries */
char *libname = 0;  /* name of the library we're generating */

	/* flags for the "outdef" function */
# define USUAL (-101)
# define DECTY (-102)
# define NOFILE (-103)
# define SVLINE (-104)

# define LNAMES 250

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

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

	*pl = *pr = VAL;
	switch( p->in.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->in.op) ) break;
		if( p->in.op == UNARY MUL && ( p->in.type == STRTY || p->in.type == UNIONTY || p->in.type == UNDEF) ) {
		/* struct x f( );  main( ) {  (void) f( ); }
		 * the the cast call appears as U* UNDEF
		 */
			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 );	CXREF */
	}


astype( t, i ) ATYPE *t; {
	TWORD tt;
	int j, k=0, l=0;

	if( (tt=BTYPE(t->aty))==STRTY || tt==UNIONTY ){
		if( i<0 || i>= DIMTABSZ-3 ){
			werror( "lint's little mind is blown" );
			}
		else {
			j = dimtab[i+3];
			if( j<0 || j>SYMTSZ ){
				k = dimtab[i];
				l = X_NONAME | stab[j].suse;
				}
			else {
				if( stab[j].suse <= 0 ) {
#ifndef FLEXNAMES
					werror( "no line number for %.8s",
#else
					werror( "no line number for %s",
#endif
						stab[j].sname );
					}
				else {
					k = dimtab[i];
#ifdef FLEXNAMES
					l = hashstr(stab[j].sname);
#else
					l = hashstr(stab[j].sname, LCHNM);
#endif
					}
				}
			}
		
		t->extra = k;
		t->extra1 = l;
		return( 1 );
		}
	else return( 0 );
	}


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

lpta( p ) NODE *p; {
	static ATYPE t;

	if( p->in.op == CM ){
		lpta( p->in.left );
		p = p->in.right;
		}

	t.aty = p->in.type;
	t.extra = (p->in.op==ICON);
	t.extra1 = 0;

	if( !astype( &t, p->fn.csiz ) ) {
		switch( t.aty ){

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

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

			case FLOAT:
				t.aty = DOUBLE;
				t.extra = 0;
				break;

			default:
				t.extra = 0;
				break;
			}
		}
	fwrite( (char *)&t, sizeof(ATYPE), 1, stdout );
	}

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


	/* print the lines for lint */

	down2 = down1 = VAL;
	acount = 0;

	switch( p->in.op ){

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

	case UGE:
	case ULT:
		if( p->in.right->in.op == ICON && p->in.right->tn.lval == 0 && p->in.right->tn.rval == NONAME ){
			werror( "unsigned comparison with 0?" );
			break;
			}
	case UGT:
	case ULE:
		if( p->in.right->in.op == ICON && p->in.right->tn.lval <= 0 && !ISUNSIGNED(p->in.right->in.type) && p->in.right->tn.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->in.left, down1, use1 );
		np2 = lnp;
		lprt( p->in.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->in.right );
	case UNARY CALL:
	case UNARY STCALL:
	case UNARY FORTCALL:
		if( p->in.left->in.op == ICON && (id=p->in.left->tn.rval) != NONAME ){ /* used to be &name */
			struct symtab *sp = &stab[id];
			int lty;

			fsave( ftitle );
			/*
			 * if we're generating a library -C then
			 * we don't want to output references to functions
			 */
			if( Cflag ) break;
			/*  if a function used in an effects context is
			 *  cast to type  void  then consider its value
			 *  to have been disposed of properly
			 *  thus a call of type  undef  in an effects
			 *  context is construed to be used in a value
			 *  context
			 */
			if ((down == EFF) && (p->in.type != UNDEF)) {
				lty = LUE;
			} else if (down == EFF) {
				lty = LUV | LUE;
			} else {
				lty = LUV;
			}
			outdef( sp, lty, acount );
			if( acount ) {
				lpta( p->in.right );
				}
			}
		break;

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

	case NAME:
		if( (id = p->tn.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 && q->stype!=UNIONTY ){
#ifndef FLEXNAMES
						werror( "%.8s may be used before set", q->sname );
#else
						werror( "%s may be used before set", q->sname );
#endif
						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->tn.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->in.op) ){

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

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

	}

lmerge( np1, np2, flag ) struct lnm *np1, *np2; {
	/* np1 and np2 point to lists of lnm members, for the two sides
	 * of a binary operator
	 * flag is 1 if commutation is possible, 0 otherwise
	 * lmerge returns a merged list, starting at np1, resetting lnp
	 * it also complains, if appropriate, about side effects
	 */

	register struct lnm *npx, *npy;

	for( npx = np2; npx < lnp; ++npx ){

		/* is it already there? */
		for( npy = np1; npy < np2; ++npy ){
			if( npx->lid == npy->lid ){ /* yes */
				if( npx->flgs == 0 || npx->flgs == (VALSET|VALUSED) )
					;  /* do nothing */
				else if( (npx->flgs|npy->flgs)== (VALSET|VALUSED) ||
					(npx->flgs&npy->flgs&VALSET) ){
#ifndef FLEXNAMES
					if( flag ) werror( "%.8s evaluation order undefined", stab[npy->lid].sname );
#else
					if( flag ) werror( "%s evaluation order undefined", stab[npy->lid].sname );
#endif
					}
				if( npy->flgs == 0 ) npx->flgs = 0;
				else npy->flgs |= npx->flgs;
				goto foundit;