// ACME - a crossassembler for producing 6502/65c02/65816/65ce02 code.
// Copyright (C) 1998-2020 Marco Baye
// Have a look at "acme.c" for further info
//
// Input stuff
#ifndef input_H
#define input_H


#include <stdio.h>	// for FILE
#include "config.h"	// for bits and scope_t


// type definitions

// values for input component "src.state"
enum inputstate {
	INPUTSTATE_SOF,		// start of file (check for hashbang)
	INPUTSTATE_NORMAL,	// everything's fine
	INPUTSTATE_AGAIN,	// re-process last byte
	INPUTSTATE_SKIPBLANKS,	// shrink multiple spaces
	INPUTSTATE_LF,		// send start-of-line after end-of-statement
	INPUTSTATE_CR,		// same, but also remember to skip LF
	INPUTSTATE_SKIPLF,	// skip LF if that's next
	INPUTSTATE_COMMENT,	// skip characters until newline or EOF
	INPUTSTATE_EOB,		// send end-of-block after end-of-statement
	INPUTSTATE_EOF,		// send end-of-file after end-of-statement
};
enum inputsrc {
	INPUTSRC_FILE,
	INPUTSRC_RAM
};
struct input {
	const char	*original_filename;	// during RAM reads, too
	int		line_number;	// in file (on RAM reads, too)
	enum inputsrc	source;
	enum inputstate	state;	// state of input
	union {
		FILE	*fd;		// file descriptor
		char	*ram_ptr;	// RAM read ptr (loop or macro block)
	} src;
};


// Constants
extern const char	FILE_READBINARY[];
// Special characters
// The program *heavily* relies on CHAR_EOS (end of statement) being 0x00!
#define CHAR_EOS	(0)	// end of statement	(in high-level format)
#define CHAR_SOB	'{'	// start of block
#define CHAR_EOB	'}'	// end of block
#define CHAR_SOL	(10)	// start of line	(in high-level format)
#define CHAR_EOF	(13)	// end of file		(in high-level format)
// if the characters above are changed, don't forget to adjust global_byte_flags[]!


// Variables
extern struct input	*Input_now;	// current input structure


// Prototypes

// let current input point to start of file
extern void Input_new_file(const char *filename, FILE *fd);
// get next byte from currently active byte source in shortened high-level
// format. When inside quotes, use Input_quoted_to_dynabuf() instead!
extern char GetByte(void);
// Skip remainder of statement, for example on error
extern void Input_skip_remainder(void);
// Ensure that the remainder of the current statement is empty, for example
// after mnemonics using implied addressing.
extern void Input_ensure_EOS(void);

// read string to dynabuf until closing quote is found
// returns 1 on errors (unterminated, escaping error)
extern int Input_quoted_to_dynabuf(char closing_quote);

// process backslash escapes in GlobalDynaBuf (so size might shrink)
// returns 1 on errors (escaping errors)
extern int Input_unescape_dynabuf(int start_index);

// Skip or store block (starting with next byte, so call directly after
// reading opening brace).
// the block is read into GlobalDynaBuf.
// If "Store" is TRUE, then a copy is made and a pointer to that is returned.
// If "Store" is FALSE, NULL is returned.
// After calling this function, GotByte holds '}'. Unless EOF was found first,
// but then a serious error would have been thrown.
extern char *Input_skip_or_store_block(boolean store);

// Append to GlobalDynaBuf while characters are legal for keywords.
// Throws "missing string" error if none. Returns number of characters added.
extern int Input_append_keyword_to_global_dynabuf(void);
// Check GotByte.
// If LOCAL_PREFIX ('.'), store current local scope value and read next byte.
// If CHEAP_PREFIX ('@'), store current cheap scope value and read next byte.
// Otherwise, store global scope value.
// Then jump to Input_read_keyword(), which returns length of keyword.
extern int Input_read_scope_and_keyword(scope_t *scope);
// Clear dynamic buffer, then append to it until an illegal (for a keyword)
// character is read. Zero-terminate the string. Return its length (without
// terminator).
// Zero lengths will produce a "missing string" error.
extern int Input_read_keyword(void);
// Clear dynamic buffer, then append to it until an illegal (for a keyword)
// character is read. Zero-terminate the string, then convert to lower case.
// Return its length (without terminator).
// Zero lengths will produce a "missing string" error.
extern int Input_read_and_lower_keyword(void);
// Try to read a file name.
// If "allow_library" is TRUE, library access by using <...> quoting
// is possible as well. If "uses_lib" is non-NULL, info about library
// usage is stored there.
// The file name given in the assembler source code is converted from
// UNIX style to platform style.
// Returns nonzero on error. Filename in GlobalDynaBuf.
// Errors are handled and reported, but caller should call
// Input_skip_remainder() then.
extern int Input_read_filename(boolean library_allowed, boolean *uses_lib);
// Try to read a comma, skipping spaces before and after. Return TRUE if comma
// found, otherwise FALSE.
extern int Input_accept_comma(void);
// read optional info about parameter length
extern bits Input_get_force_bit(void);


// include path stuff - should be moved to its own file:

// add entry
extern void includepaths_add(const char *path);
// open file for reading (trying list entries as prefixes)
// "uses_lib" tells whether to access library or to make use of include paths
// file name is expected in GlobalDynaBuf
extern FILE *includepaths_open_ro(boolean uses_lib);


#endif