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// license:BSD-3-Clause
// copyright-holders:Aaron Giles
/***************************************************************************
express.h
Generic expressions engine.
***************************************************************************/
#pragma once
#ifndef __EXPRESS_H__
#define __EXPRESS_H__
#include "emu.h"
//**************************************************************************
// CONSTANTS
//**************************************************************************
// values for the address space passed to external_read/write_memory
enum expression_space
{
EXPSPACE_INVALID,
EXPSPACE_PROGRAM_LOGICAL,
EXPSPACE_DATA_LOGICAL,
EXPSPACE_IO_LOGICAL,
EXPSPACE_SPACE3_LOGICAL,
EXPSPACE_PROGRAM_PHYSICAL,
EXPSPACE_DATA_PHYSICAL,
EXPSPACE_IO_PHYSICAL,
EXPSPACE_SPACE3_PHYSICAL,
EXPSPACE_OPCODE,
EXPSPACE_RAMWRITE,
EXPSPACE_REGION
};
//**************************************************************************
// TYPE DEFINITIONS
//**************************************************************************
// forward references
class symbol_table;
// ======================> expression_error
// an expression_error holds an error code and a string offset
class expression_error
{
public:
// codes
enum error_code
{
NONE,
NOT_LVAL,
NOT_RVAL,
SYNTAX,
UNKNOWN_SYMBOL,
INVALID_NUMBER,
INVALID_TOKEN,
STACK_OVERFLOW,
STACK_UNDERFLOW,
UNBALANCED_PARENS,
DIVIDE_BY_ZERO,
OUT_OF_MEMORY,
INVALID_PARAM_COUNT,
UNBALANCED_QUOTES,
TOO_MANY_STRINGS,
INVALID_MEMORY_SIZE,
INVALID_MEMORY_SPACE,
NO_SUCH_MEMORY_SPACE,
INVALID_MEMORY_NAME,
MISSING_MEMORY_NAME
};
// construction/destruction
expression_error(error_code code, int offset = 0)
: m_code(code),
m_offset(offset) { }
// operators
operator error_code() const { return m_code; }
// getters
error_code code() const { return m_code; }
int offset() const { return m_offset; }
const char *code_string() const;
private:
// internal state
error_code m_code;
int m_offset;
};
// ======================> symbol_entry
// symbol_entry describes a symbol in a symbol table
class symbol_entry
{
friend class simple_list<symbol_entry>;
protected:
// symbol types
enum symbol_type
{
SMT_INTEGER,
SMT_FUNCTION
};
// construction/destruction
symbol_entry(symbol_table &table, symbol_type type, const char *name, void *ref);
virtual ~symbol_entry();
public:
// getters
symbol_entry *next() const { return m_next; }
const char *name() const { return m_name.c_str(); }
// type checking
bool is_function() const { return (m_type == SMT_FUNCTION); }
// symbol access
virtual bool is_lval() const = 0;
virtual UINT64 value() const = 0;
virtual void set_value(UINT64 newvalue) = 0;
protected:
// internal state
symbol_entry * m_next; // link to next entry
symbol_table & m_table; // pointer back to the owning table
symbol_type m_type; // type of symbol
std::string m_name; // name of the symbol
void * m_ref; // internal reference
};
// ======================> symbol_table
// a symbol_table holds symbols of various types which the expression engine
// queries to look up symbols
class symbol_table
{
public:
// callback functions for getting/setting a symbol value
typedef UINT64 (*getter_func)(symbol_table &table, void *symref);
typedef void (*setter_func)(symbol_table &table, void *symref, UINT64 value);
// callback functions for function execution
typedef UINT64 (*execute_func)(symbol_table &table, void *symref, int numparams, const UINT64 *paramlist);
// callback functions for memory reads/writes
typedef expression_error::error_code (*valid_func)(void *cbparam, const char *name, expression_space space);
typedef UINT64 (*read_func)(void *cbparam, const char *name, expression_space space, UINT32 offset, int size);
typedef void (*write_func)(void *cbparam, const char *name, expression_space space, UINT32 offset, int size, UINT64 value);
enum read_write
{
READ_ONLY = 0,
READ_WRITE
};
// construction/destruction
symbol_table(void *globalref, symbol_table *parent = NULL);
// getters
symbol_entry *first() const { return m_symlist.first(); }
symbol_table *parent() const { return m_parent; }
void *globalref() const { return m_globalref; }
// setters
void configure_memory(void *param, valid_func valid, read_func read, write_func write);
// symbol access
void add(const char *name, read_write rw, UINT64 *ptr = NULL);
void add(const char *name, UINT64 constvalue);
void add(const char *name, void *ref, getter_func getter, setter_func setter = NULL);
void add(const char *name, void *ref, int minparams, int maxparams, execute_func execute);
symbol_entry *find(const char *name) { return m_symlist.find(name); }
symbol_entry *find_deep(const char *name);
// value getter/setter
UINT64 value(const char *symbol);
void set_value(const char *symbol, UINT64 value);
// memory accessors
expression_error::error_code memory_valid(const char *name, expression_space space);
UINT64 memory_value(const char *name, expression_space space, UINT32 offset, int size);
void set_memory_value(const char *name, expression_space space, UINT32 offset, int size, UINT64 value);
private:
// internal state
symbol_table * m_parent; // pointer to the parent symbol table
void * m_globalref; // global reference parameter
tagged_list<symbol_entry> m_symlist; // list of symbols
void * m_memory_param; // callback parameter for memory
valid_func m_memory_valid; // validation callback
read_func m_memory_read; // read callback
write_func m_memory_write; // write callback
};
// ======================> parsed_expression
// a parsed_expression holds a pre-parsed expression that can be
// efficiently executed at a later time
class parsed_expression
{
public:
// construction/destruction
parsed_expression(const parsed_expression &src) { copy(src); }
parsed_expression(symbol_table *symtable = NULL, const char *expression = NULL, UINT64 *result = NULL);
// operators
parsed_expression &operator=(const parsed_expression &src) { copy(src); return *this; }
// getters
bool is_empty() const { return (m_tokenlist.count() == 0); }
const char *original_string() const { return m_original_string.c_str(); }
symbol_table *symbols() const { return m_symtable; }
// setters
void set_symbols(symbol_table *symtable) { m_symtable = symtable; }
// execution
void parse(const char *string);
UINT64 execute() { return execute_tokens(); }
private:
// a single token
class parse_token
{
friend class simple_list<parse_token>;
// operator flags
enum
{
TIN_OPTYPE_SHIFT = 0, // 8 bits (0-7)
TIN_OPTYPE_MASK = 0xff << TIN_OPTYPE_SHIFT,
TIN_RIGHT_TO_LEFT_SHIFT = 16, // 1 bit (16)
TIN_RIGHT_TO_LEFT_MASK = 1 << TIN_RIGHT_TO_LEFT_SHIFT,
TIN_FUNCTION_SHIFT = 17, // 1 bit (17)
TIN_FUNCTION_MASK = 1 << TIN_FUNCTION_SHIFT,
TIN_MEMORY_SIZE_SHIFT = 18, // 2 bits (18-19)
TIN_MEMORY_SIZE_MASK = 3 << TIN_MEMORY_SIZE_SHIFT,
TIN_MEMORY_SPACE_SHIFT = 20, // 4 bits (20-23)
TIN_MEMORY_SPACE_MASK = 0xf << TIN_MEMORY_SPACE_SHIFT,
TIN_PRECEDENCE_SHIFT = 24, // 8 bits (24-31)
TIN_PRECEDENCE_MASK = 0xff << TIN_PRECEDENCE_SHIFT
};
// types of tokens
enum token_type
{
INVALID = 0,
NUMBER,
STRING,
MEMORY,
SYMBOL,
OPERATOR
};
public:
// construction/destruction
parse_token(int offset = 0);
// getters
parse_token *next() const { return m_next; }
int offset() const { return m_offset; }
bool is_number() const { return (m_type == NUMBER); }
bool is_string() const { return (m_type == STRING); }
bool is_memory() const { return (m_type == MEMORY); }
bool is_symbol() const { return (m_type == SYMBOL); }
bool is_operator() const { return (m_type == OPERATOR); }
bool is_operator(UINT8 type) const { return (m_type == OPERATOR && optype() == type); }
bool is_lval() const { return ((m_type == SYMBOL && m_symbol->is_lval()) || m_type == MEMORY); }
UINT64 value() const { assert(m_type == NUMBER); return m_value; }
UINT32 address() const { assert(m_type == MEMORY); return m_value; }
symbol_entry *symbol() const { assert(m_type == SYMBOL); return m_symbol; }
UINT8 optype() const { assert(m_type == OPERATOR); return (m_flags & TIN_OPTYPE_MASK) >> TIN_OPTYPE_SHIFT; }
UINT8 precedence() const { assert(m_type == OPERATOR); return (m_flags & TIN_PRECEDENCE_MASK) >> TIN_PRECEDENCE_SHIFT; }
bool is_function_separator() const { assert(m_type == OPERATOR); return ((m_flags & TIN_FUNCTION_MASK) != 0); }
bool right_to_left() const { assert(m_type == OPERATOR); return ((m_flags & TIN_RIGHT_TO_LEFT_MASK) != 0); }
expression_space memory_space() const { assert(m_type == OPERATOR || m_type == MEMORY); return expression_space((m_flags & TIN_MEMORY_SPACE_MASK) >> TIN_MEMORY_SPACE_SHIFT); }
int memory_size() const { assert(m_type == OPERATOR || m_type == MEMORY); return (m_flags & TIN_MEMORY_SIZE_MASK) >> TIN_MEMORY_SIZE_SHIFT; }
// setters
parse_token &set_offset(int offset) { m_offset = offset; return *this; }
parse_token &set_offset(const parse_token &src) { m_offset = src.m_offset; return *this; }
parse_token &set_offset(const parse_token &src1, const parse_token &src2) { m_offset = MIN(src1.m_offset, src2.m_offset); return *this; }
parse_token &configure_number(UINT64 value) { m_type = NUMBER; m_value = value; return *this; }
parse_token &configure_string(const char *string) { m_type = STRING; m_string = string; return *this; }
parse_token &configure_memory(UINT32 address, parse_token &memoryat) { m_type = MEMORY; m_value = address; m_flags = memoryat.m_flags; m_string = memoryat.m_string; return *this; }
parse_token &configure_symbol(symbol_entry &symbol) { m_type = SYMBOL; m_symbol = &symbol; return *this; }
parse_token &configure_operator(UINT8 optype, UINT8 precedence)
{ m_type = OPERATOR; m_flags = ((optype << TIN_OPTYPE_SHIFT) & TIN_OPTYPE_MASK) | ((precedence << TIN_PRECEDENCE_SHIFT) & TIN_PRECEDENCE_MASK); return *this; }
parse_token &set_function_separator() { assert(m_type == OPERATOR); m_flags |= TIN_FUNCTION_MASK; return *this; }
parse_token &set_right_to_left() { assert(m_type == OPERATOR); m_flags |= TIN_RIGHT_TO_LEFT_MASK; return *this; }
parse_token &set_memory_space(expression_space space) { assert(m_type == OPERATOR || m_type == MEMORY); m_flags = (m_flags & ~TIN_MEMORY_SPACE_MASK) | ((space << TIN_MEMORY_SPACE_SHIFT) & TIN_MEMORY_SPACE_MASK); return *this; }
parse_token &set_memory_size(int log2ofbits) { assert(m_type == OPERATOR || m_type == MEMORY); m_flags = (m_flags & ~TIN_MEMORY_SIZE_MASK) | ((log2ofbits << TIN_MEMORY_SIZE_SHIFT) & TIN_MEMORY_SIZE_MASK); return *this; }
parse_token &set_memory_source(const char *string) { assert(m_type == OPERATOR || m_type == MEMORY); m_string = string; return *this; }
// access
UINT64 get_lval_value(symbol_table *symtable);
void set_lval_value(symbol_table *symtable, UINT64 value);
private:
// internal state
parse_token * m_next; // next token in list
token_type m_type; // type of token
int m_offset; // offset within the string
UINT64 m_value; // integral value
UINT32 m_flags; // additional flags/info
const char * m_string; // associated string
symbol_entry * m_symbol; // symbol pointer
};
// an expression_string holds an indexed string parsed from the expression
class expression_string
{
friend class simple_list<expression_string>;
public:
// construction/destruction
expression_string(const char *string, int length = 0)
: m_next(NULL),
m_string(string, (length == 0) ? strlen(string) : length) { }
// operators
operator const char *() { return m_string.c_str(); }
operator const char *() const { return m_string.c_str(); }
private:
// internal state
expression_string * m_next; // next string in list
std::string m_string; // copy of the string
};
// internal helpers
void copy(const parsed_expression &src);
void print_tokens(FILE *out);
// parsing helpers
void parse_string_into_tokens();
void parse_symbol_or_number(parse_token &token, const char *&string);
void parse_number(parse_token &token, const char *string, int base, expression_error::error_code errcode);
void parse_quoted_char(parse_token &token, const char *&string);
void parse_quoted_string(parse_token &token, const char *&string);
void parse_memory_operator(parse_token &token, const char *string);
void normalize_operator(parse_token *prevtoken, parse_token &thistoken);
void infix_to_postfix();
// execution helpers
void push_token(parse_token &token);
void pop_token(parse_token &token);
parse_token *peek_token(int count);
void pop_token_lval(parse_token &token);
void pop_token_rval(parse_token &token);
UINT64 execute_tokens();
void execute_function(parse_token &token);
// constants
static const int MAX_FUNCTION_PARAMS = 16;
static const int MAX_STACK_DEPTH = 16;
// internal state
symbol_table * m_symtable; // symbol table
std::string m_original_string; // original string (prior to parsing)
simple_list<parse_token> m_tokenlist; // token list
simple_list<expression_string> m_stringlist; // string list
int m_token_stack_ptr; // stack pointer (used during execution)
parse_token m_token_stack[MAX_STACK_DEPTH]; // token stack (used during execution)
};
#endif
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