Rev 2 | Blame | Compare with Previous | Last modification | View Log | RSS feed
/*
Crown Copyright (c) 1997
This TenDRA(r) Computer Program is subject to Copyright
owned by the United Kingdom Secretary of State for Defence
acting through the Defence Evaluation and Research Agency
(DERA). It is made available to Recipients with a
royalty-free licence for its use, reproduction, transfer
to other parties and amendment for any purpose not excluding
product development provided that any such use et cetera
shall be deemed to be acceptance of the following conditions:-
(1) Its Recipients shall ensure that this Notice is
reproduced upon any copies or amended versions of it;
(2) Any amended version of it shall be clearly marked to
show both the nature of and the organisation responsible
for the relevant amendment or amendments;
(3) Its onward transfer from a recipient to another
party shall be deemed to be that party's acceptance of
these conditions;
(4) DERA gives no warranty or assurance as to its
quality or suitability for any purpose and DERA accepts
no liability whatsoever in relation to any use to which
it may be put.
*/
#include "config.h"
#include "calculus.h"
#include "error.h"
#include "lex.h"
#include "syntax.h"
#include "xalloc.h"
/*
INPUT FLAGS
The flag new_format is set to true to indicate the new input format.
The flags allow_stack and allow_vec are set to false to suppress the
stack and vector operations respectively.
*/
int new_format = 1 ;
int allow_stack = 1 ;
int allow_vec = 1 ;
/*
CHECK STACK FLAG
This routine is called if the STACK keyword is encountered to check the
value of allow_stack.
*/
static int check_stack
PROTO_N ( ( t ) )
PROTO_T ( int t )
{
if ( !allow_stack ) {
error ( ERROR_SERIOUS, "Stack operations have been suppressed" ) ;
allow_stack = 1 ;
}
return ( t ) ;
}
/*
CHECK VECTOR FLAG
This routine is called if the VEC or VEC_PTR keywords are encountered
to check the value of allow_vec.
*/
static int check_vec
PROTO_N ( ( t ) )
PROTO_T ( int t )
{
if ( !allow_vec ) {
error ( ERROR_SERIOUS, "Vector operations have been suppressed" ) ;
allow_vec = 1 ;
}
return ( t ) ;
}
/*
INPUT FILE
This is the file from which the lexical routine read their input.
*/
static FILE *lex_input ;
/*
PENDING BUFFER
Pending characters are dealt with by means of this buffer. pending
is set to the start of the buffer to indicate that there are no
characters pending, otherwise the pending characters are stored in
the buffer. The buffer may need increasing in size if the look-ahead
required by the lexical analyser increases.
*/
static int pending_buff [12] = { '?' } ;
static int *pending = pending_buff ;
/*
MAPPINGS AND DECLARATIONS FOR AUTOMATICALLY GENERATED SECTION
These macros give the mappings between the actions used in the
automatically generated lexical analyser and the routines defined
in this file.
*/
static int read_char PROTO_S ( ( void ) ) ;
static int read_comment PROTO_S ( ( void ) ) ;
static int read_hex PROTO_S ( ( int ) ) ;
static int read_identifier PROTO_S ( ( int ) ) ;
static int read_number PROTO_S ( ( int ) ) ;
static int read_string PROTO_S ( ( void ) ) ;
#define get_comment( A, B ) read_comment ()
#define get_hex( A, B, C ) read_hex ( C )
#define get_identifier( A ) read_identifier ( A )
#define get_number( A ) read_number ( A )
#define get_string( A ) read_string ()
#define get_stack() check_stack ( lex_stack )
#define get_vec() check_vec ( lex_vec )
#define get_vec_ptr() check_vec ( lex_vec_Hptr )
#define unknown_token( A ) lex_unknown
#define unread_char( A ) *( ++pending ) = ( A )
/*
AUTOMATICALLY GENERATED SECTION
The main body of the lexical analyser is automatically generated.
*/
#include "lexer.h"
/*
GET THE NEXT CHARACTER
This routine reads the next character, either from the pending buffer
or from the input file.
*/
static int read_char
PROTO_Z ()
{
int c ;
if ( pending != pending_buff ) {
c = *( pending-- ) ;
} else {
c = fgetc ( lex_input ) ;
if ( c == '\n' ) crt_line_no++ ;
if ( c == EOF ) return ( LEX_EOF ) ;
c &= 0xff ;
}
return ( c ) ;
}
/*
TOKEN BUFFER
This buffer is used by read_token to hold the values of identifiers
and strings. The variable token_value is also used to hold the
values of numbers.
*/
char token_buff [2000] ;
static char *token_end = token_buff + sizeof ( token_buff ) ;
char *first_comment = NULL ;
number token_value ;
/*
READ AN IDENTIFIER
This routine reads an identifier beginning with a, returning the
corresponding lexical token. Keywords are dealt with locally.
*/
static int read_identifier
PROTO_N ( ( a ) )
PROTO_T ( int a )
{
int c = a, cl ;
char *t = token_buff ;
do {
*( t++ ) = ( char ) c ;
if ( t == token_end ) error ( ERROR_FATAL, "Buffer overflow" ) ;
c = read_char () ;
cl = lookup_char ( c ) ;
} while ( is_alphanum ( cl ) ) ;
*t = 0 ;
unread_char ( c ) ;
/* Check for keywords */
t = token_buff ;
#define MAKE_KEYWORD( A, B )\
if ( streq ( t, ( A ) ) ) return ( B ) ;
#include "keyword.h"
return ( lex_identifier ) ;
}
/*
READ A NUMBER
This routine reads a number beginning with a, returning the
corresponding lexical token. The actual value of the number is built
up in token_value.
*/
static int read_number
PROTO_N ( ( a ) )
PROTO_T ( int a )
{
int c = a, cl ;
number n = 0 ;
do {
n = 10 * n + ( number ) ( c - '0' ) ;
c = read_char () ;
cl = lookup_char ( c ) ;
} while ( is_digit ( cl ) ) ;
unread_char ( c ) ;
token_value = n ;
return ( lex_number ) ;
}
/*
READ A HEXADECIMAL NUMBER
This routine reads a hexadecimal number beginning with a, returning the
corresponding lexical token. The actual value of the number is built
up in token_value.
*/
static int read_hex
PROTO_N ( ( a ) )
PROTO_T ( int a )
{
int c = a, cl ;
number n = 0 ;
do {
number d ;
if ( c >= '0' && c <= '9' ) {
d = ( number ) ( c - '0' ) ;
} else if ( c >= 'A' && c <= 'Z' ) {
d = ( number ) ( c - 'A' ) + 10 ;
} else {
d = ( number ) ( c - 'a' ) + 10 ;
}
n = 16 * n + d ;
c = read_char () ;
cl = lookup_char ( c ) ;
} while ( is_hexdigit ( cl ) ) ;
unread_char ( c ) ;
token_value = n ;
return ( lex_number ) ;
}
/*
READ A STRING
This routine reads a string. It is entered after the initial
quote has been read. Note that there are no escape sequences.
*/
static int read_string
PROTO_Z ()
{
int c ;
char *t = token_buff ;
while ( c = read_char (), c != '"' ) {
if ( c == '\n' || c == LEX_EOF ) {
error ( ERROR_SERIOUS, "Unexpected end of string" ) ;
break ;
}
*( t++ ) = ( char ) c ;
if ( t == token_end ) error ( ERROR_FATAL, "Buffer overflow" ) ;
}
*t = 0 ;
return ( lex_string ) ;
}
/*
READ A COMMENT
This routine reads a C style comment, returning the lexical token
immediately following. It is entered after the first two characters
have been read.
*/
static int read_comment
PROTO_Z ()
{
int state = 0 ;
char *t = token_buff ;
*( t++ ) = '/' ;
*( t++ ) = '*' ;
while ( state != 2 ) {
int c = read_char () ;
if ( c == LEX_EOF ) {
error ( ERROR_SERIOUS, "End of file in comment" ) ;
return ( lex_eof ) ;
}
if ( c == '*' ) {
state = 1 ;
} else if ( state == 1 && c == '/' ) {
state = 2 ;
} else {
state = 0 ;
}
*( t++ ) = ( char ) c ;
if ( t == token_end ) t = token_buff + 2 ;
}
*t = 0 ;
if ( first_comment == NULL ) first_comment = xstrcpy ( token_buff ) ;
return ( read_token () ) ;
}
/*
CURRENT TOKEN
These variables are used by the parser to hold the current and former
lexical tokens.
*/
int crt_lex_token ;
int saved_lex_token ;
/*
PROCESS FILE
This routine processes the input file nm. If r is true then it is
processed using read_calculus, otherwise extra_calculus is used.
*/
void process_file
PROTO_N ( ( nm, r ) )
PROTO_T ( char *nm X int r )
{
crt_line_no = 1 ;
crt_file_name = nm ;
lex_input = fopen ( nm, "r" ) ;
if ( lex_input == NULL ) {
error ( ERROR_SERIOUS, "Can't open input file, '%s'", nm ) ;
return ;
}
ADVANCE_LEXER ;
if ( r ) {
read_calculus () ;
} else {
extra_calculus () ;
}
if ( crt_lex_token != lex_eof ) {
error ( ERROR_SERIOUS, "Terminating due to syntax error" ) ;
}
fclose_v ( lex_input ) ;
return ;
}