pc3.c

早期freebsd实现

			}
			    /*
			     *	something is wrong
			     *	if it's not resolved, use the header file
			     *	otherwise, it's just a regular error
			     */
			if ( symbolp -> sym_un.sym_str.rfilep == NIL ) {
			    error( ERROR ,
		    "%s, line %d: %s is already defined\n\t(%s, line %d)." ,
				ifilep -> name , nlp -> n_value , 
				nlp -> n_un.n_name , 
				symbolp -> sym_un.sym_str.fromi -> name ,
				symbolp -> sym_un.sym_str.iline );
			    return;
			}
			break;
		case N_PGFUNC:
		case N_PGPROC:
			    /*
			     *	functions may not be seen more than once.
			     *	the loader will complain about
			     *	`multiply defined', but we can, too.
			     */
			break;
		case N_PGLABEL:
		case N_PGCONST:
		case N_PGTYPE:
		case N_PGVAR:
			    /*
			     *	labels, constants, types, variables
			     *	and external declarations
			     *	may be seen as many times as they want,
			     *	as long as they come from the same include file.
			     *	make it look like they come from this .p file.
			     */
included:
			if (  nlp -> n_desc != symbolp -> desc
			   || symbolp -> sym_un.sym_str.fromi != ifilep ) {
			    break;
			}
			symbolp -> fromp = pfilep;
			return;
		case N_PLDATA:
		case N_PLTEXT:
			switch ( nlp -> n_desc ) {
			    default:
				error( FATAL , "pc3: unknown stab 0x%x"
					, nlp -> n_desc );
				return;
			    case N_PSO:
			    case N_PSOL:
			    case N_PGCONST:
			    case N_PGTYPE:
				/* these won't conflict with library */
				return;
			    case N_PGLABEL:
			    case N_PGVAR:
			    case N_PGFUNC:
			    case N_PGPROC:
			    case N_PEFUNC:
			    case N_PEPROC:
			    case N_PLDATA:
			    case N_PLTEXT:
				errtype = WARNING;
				break;
			}
			break;
	    }
		/*
		 *	this is the breaks
		 */
	    error( errtype
		, "%s, line %d: %s %s is already defined\n\t%s%s (%s, line %d)."
		, ifilep -> name
		, nlp -> n_value
		, classify( nlp -> n_desc )
		, nlp -> n_un.n_name
		, ( symbolp -> desc == nlp -> n_desc ? "" : " as " )
		, ( symbolp -> desc == nlp -> n_desc
			? "" : article( symbolp -> desc ) )
		, symbolp -> sym_un.sym_str.rfilep -> name
		, symbolp -> sym_un.sym_str.rline );
	}
    }

    /*
     *	quadratically hashed symbol table.
     *	things are never deleted from the hash symbol table.
     *	as more hash table is needed,
     *	a new one is alloc'ed and chained to the end.
     *	search is by rehashing within each table,
     *	traversing chains to next table if unsuccessful.
     */
struct symbol *
entersymbol( name )
    char	*name;
    {
	static struct symboltableinfo	symboltable;
	char				*enteredname;
	long				hashindex;
	register struct symboltableinfo	*tablep;
	register struct symbol		**herep;
	register struct symbol		**limitp;
	register long			increment;

	enteredname = enterstring( name );
	hashindex = SHORT_ABS( ( long ) enteredname ) % SYMBOLPRIME;
	for ( tablep = &symboltable ; /*return*/ ; tablep = tablep -> chain ) {
	    if ( tablep == NIL ) {
#		ifdef SPACEDEBUG
		    fprintf( stderr ,
			    "[entersymbol] calloc'ing table for %d symbols\n" , 
			    SYMBOLPRIME );
#		endif SPACEDEBUG
		for ( tablep = &symboltable
		    ; tablep->chain != NIL
		    ; tablep = tablep->chain ) {
			continue;
		}
		tablep->chain = ( struct symboltableinfo * )
			    calloc( 1 , sizeof ( struct symboltableinfo ) );
		if ( tablep->chain == NIL ) {
		    error( FATAL , "ran out of memory (entersymbol)" );
		}
		tablep = tablep->chain;
	    }
	    herep = &( tablep -> entry[ hashindex ] );
	    limitp = &( tablep -> entry[ SYMBOLPRIME ] );
	    increment = 1;
	    do {
		if ( *herep == NIL ) {
			/* empty */
		    if ( tablep -> used > ( ( SYMBOLPRIME / 4 ) * 3 ) ) {
			    /* too full, break for next table */
			break;
		    }
		    tablep -> used++;
		    *herep = symbolalloc();
		    ( *herep ) -> name = enteredname;
		    ( *herep ) -> lookup = NEW;
#		    ifdef HASHDEBUG
			fprintf( stderr ,
				"[entersymbol] name %s NEW after %d\n" ,
				enteredname , increment / 2 );
#		    endif HASHDEBUG
		    return *herep;
		}
		    /* a find? */
		if ( ( *herep ) -> name == enteredname ) {
		    ( *herep ) -> lookup = OLD;
#		    ifdef HASHDEBUG
			fprintf( stderr , "[entersymbol] name %s OLD at %d\n" ,
				enteredname , increment / 2 );
#		    endif HASHDEBUG
		    return *herep;
		}
		herep += increment;
		if ( herep >= limitp ) {
		    herep -= SYMBOLPRIME;
		}
		increment += 2;
	    } while ( increment < SYMBOLPRIME );
#	    ifdef HASHDEBUG
		fprintf( stderr , "[entersymbol] next symboltable\n" );
#	    endif HASHDEBUG
	}
    }

    /*
     *	allocate a symbol from the dynamically allocated symbol table.
     */
struct symbol *
symbolalloc()
    {
	static struct symbol	*nextsymbol = NIL;
	static long		symbolsleft = 0;
	struct symbol		*newsymbol;

	if ( symbolsleft <= 0 ) {
#	    ifdef SPACEDEBUG
		fprintf( stderr ,
			"[symbolalloc] malloc space for %d symbols\n" ,
			SYMBOLALLOC / sizeof( struct symbol ) );
#	    endif SPACEDEBUG
	    nextsymbol = ( struct symbol * ) malloc( SYMBOLALLOC );
	    if ( nextsymbol == 0 ) {
		error( FATAL , "ran out of memory (symbolalloc)" );
	    }
	    symbolsleft = SYMBOLALLOC / sizeof( struct symbol );
	}
	newsymbol = nextsymbol;
	nextsymbol++;
	symbolsleft--;
	return newsymbol;
    }

    /*
     *	hash a string based on all of its characters.
     */
long
hashstring( string )
    char	*string;
    {
	register char	*cp;
	register long	value;

	value = 0;
	for ( cp = string ; *cp ; cp++ ) {
	    value = ( value * 2 ) + *cp;
	}
	return value;
    }

    /*
     *	quadratically hashed string table.
     *	things are never deleted from the hash string table.
     *	as more hash table is needed,
     *	a new one is alloc'ed and chained to the end.
     *	search is by rehashing within each table,
     *	traversing chains to next table if unsuccessful.
     */
char *
enterstring( string )
    char	*string;
    {
	static struct stringtableinfo	stringtable;
	long				hashindex;
	register struct stringtableinfo	*tablep;
	register char			**herep;
	register char			**limitp;
	register long			increment;

	hashindex = SHORT_ABS( hashstring( string ) ) % STRINGPRIME;
	for ( tablep = &stringtable ; /*return*/ ; tablep = tablep -> chain ) {
	    if ( tablep == NIL ) {
#		ifdef SPACEDEBUG
		    fprintf( stderr ,
			    "[enterstring] calloc space for %d strings\n" ,
			    STRINGPRIME );
#		endif SPACEDEBUG
		for ( tablep = &stringtable
		    ; tablep->chain != NIL
		    ; tablep = tablep->chain ) {
			continue;
		}
		tablep->chain = ( struct stringtableinfo * )
			    calloc( 1 , sizeof ( struct stringtableinfo ) );
		if ( tablep->chain == NIL ) {
		    error( FATAL , "ran out of memory (enterstring)" );
		}
		tablep = tablep->chain;
	    }
	    herep = &( tablep -> entry[ hashindex ] );
	    limitp = &( tablep -> entry[ STRINGPRIME ] );
	    increment = 1;
	    do {
		if ( *herep == NIL ) {
			/* empty */
		    if ( tablep -> used > ( ( STRINGPRIME / 4 ) * 3 ) ) {
			    /* too full, break for next table */
			break;
		    }
		    tablep -> used++;
		    *herep = charalloc( strlen( string ) );
		    strcpy( *herep , string );
#		    ifdef HASHDEBUG
			fprintf( stderr ,
				"[enterstring] string %s copied after %d\n" , 
				*herep , increment / 2 );
#		    endif HASHDEBUG
		    return *herep;
		}
		    /* quick, check the first chars and then the rest */
		if ( **herep == *string && strcmp( *herep , string ) == 0 ) {
#		    ifdef HASHDEBUG
			fprintf( stderr ,
				"[enterstring] string %s found after %d\n" ,
				*herep , increment / 2 );
#		    endif HASHDEBUG
		    return *herep;
		}
		herep += increment;
		if ( herep >= limitp ) {
		    herep -= STRINGPRIME;
		}
		increment += 2;
	    } while ( increment < STRINGPRIME );
#	    ifdef HASHDEBUG
		fprintf( stderr , "[enterstring] next stringtable\n" );
#	    endif HASHDEBUG
	}
    }

    /*
     *	copy a string to the dynamically allocated character table.
     */
char *
charalloc( length )
    register long	length;
    {
	static char	*nextchar = NIL;
	static long	charsleft = 0;
	register long	lengthplus1 = length + 1;
	register long	askfor;
	char		*newstring;

	if ( charsleft < lengthplus1 ) {
	    askfor = lengthplus1 > CHARALLOC ? lengthplus1 : CHARALLOC;
#	    ifdef SPACEDEBUG
		fprintf( stderr , "[charalloc] malloc space for %d chars\n" 
			, askfor );
#	    endif SPACEDEBUG
	    nextchar = ( char * ) malloc( askfor );
	    if ( nextchar == 0 ) {
		error( FATAL , "no room for %d characters" , askfor );
	    }
	    charsleft = askfor;
	}
	newstring = nextchar;
	nextchar += lengthplus1;
	charsleft -= lengthplus1;
	return newstring;
    }

    /*
     *	read an archive header for the next element
     *	and find the offset of the one after this. 
     */
BOOL
nextelement( ofilep )
    struct fileinfo	*ofilep;
    {
	register char	*cp;
	register long	red;
	register off_t	arsize;
	struct ar_hdr	archdr;

	fseek( ofilep -> file , ofilep -> nextoffset , 0 );
	red = fread( (char *) &archdr , 1 , sizeof archdr , ofilep -> file );
	if ( red != sizeof archdr ) {
	    return FALSE;
	}
	    /* null terminate the blank-padded name */
	cp = &archdr.ar_name[ ( sizeof archdr.ar_name ) - 1 ];
	*cp = '\0';
	while ( *--cp == ' ' ) {
	    *cp = '\0';
	}
	    /* set up the address of the beginning of next element */
	arsize = atol( archdr.ar_size );
	    /* archive elements are aligned on 0 mod 2 boundaries */
	if ( arsize & 1 ) {
	    arsize += 1;
	}
	ofilep -> nextoffset = ftell( ofilep -> file ) + arsize;
	    /* say we had one */
	return TRUE;
    }

    /*
     *	variable number of arguments to error, like printf.
     */
error( type , message , arg1 , arg2 , arg3 , arg4 , arg5 , arg6 , arg7 , arg8 )
    int		type;
    char	*message;
    {
	errors = type > errors ? type : errors;
	if ( wflag && type == WARNING ) {
	    return;
	}
	fprintf( stderr , "%s: " , program );
	switch ( type ) {
	    case WARNING:
		    fprintf( stderr , "Warning: " );
		    break;
	    case ERROR:
		    fprintf( stderr , "Error: " );
		    break;
	    case FATAL:
		    fprintf( stderr , "Fatal: " );
		    break;
	    default:
		    fprintf( stderr , "Ooops: " );
		    break;
	}
	fprintf( stderr , message , arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8 );
	fprintf( stderr , "\n" );
	if ( type == FATAL ) {
	    exit( FATAL );
	}
    }

char *
classify( type )
    unsigned char	type;
    {
	switch ( type ) {
	    case N_PSO:
		return "source file";
	    case N_PSOL:
		return "include file";
	    case N_PGLABEL:
		return "label";
	    case N_PGCONST:
		return "constant";
	    case N_PGTYPE:
		return "type";
	    case N_PGVAR:
		return "variable";
	    case N_PGFUNC:
		return "function";
	    case N_PGPROC:
		return "procedure";
	    case N_PEFUNC:
		return "external function";
	    case N_PEPROC:
		return "external procedure";
	    case N_PLDATA:
		return "library variable";
	    case N_PLTEXT:
		return "library routine";
	    default:
		return "unknown symbol";
	}
    }

char *
article( type )
    unsigned char	type;
    {
	switch ( type ) {
	    case N_PSO:
		return "a source file";
	    case N_PSOL:
		return "an include file";
	    case N_PGLABEL:
		return "a label";
	    case N_PGCONST:
		return "a constant";
	    case N_PGTYPE:
		return "a type";
	    case N_PGVAR:
		return "a variable";
	    case N_PGFUNC:
		return "a function";
	    case N_PGPROC:
		return "a procedure";
	    case N_PEFUNC:
		return "an external function";
	    case N_PEPROC:
		return "an external procedure";
	    case N_PLDATA:
		return "a library variable";
	    case N_PLTEXT:
		return "a library routine";
	    default:
		return "an unknown symbol";
	}
    }