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// SPDX-License-Identifier: MIT OR MPL-2.0 OR LGPL-2.1-or-later OR GPL-2.0-or-later
// Copyright 2010, SIL International, All rights reserved.
// This general interpreter interface.
// Author: Tim Eves
// Build one of direct_machine.cpp or call_machine.cpp to implement this
// interface.
#pragma once
#include <cstring>
#include <limits>
#include <graphite2/Types.h>
#include "inc/Main.h"
#if defined(__GNUC__)
#if defined(__clang__) || (__GNUC__ * 100 + __GNUC_MINOR__ * 10) < 430
#define HOT
#if defined(__x86_64)
#define REGPARM(n) __attribute__((regparm(n)))
#else
#define REGPARM(n)
#endif
#else
#define HOT __attribute__((hot))
#if defined(__x86_64)
#define REGPARM(n) __attribute__((hot, regparm(n)))
#else
#define REGPARM(n)
#endif
#endif
#else
#define HOT
#define REGPARM(n)
#endif
#if defined(__MINGW32__)
// MinGW's <limits> at some point includes winnt.h which #define's a
// DELETE macro, which conflicts with enum opcode below, so we undefine
// it here.
#undef DELETE
#endif
namespace graphite2 {
// Forward declarations
class Segment;
class Slot;
class SlotMap;
namespace vm
{
typedef void * instr;
typedef Slot * slotref;
enum {VARARGS = 0xff, MAX_NAME_LEN=32};
enum opcode {
NOP = 0,
PUSH_BYTE, PUSH_BYTEU, PUSH_SHORT, PUSH_SHORTU, PUSH_LONG,
ADD, SUB, MUL, DIV,
MIN_, MAX_,
NEG,
TRUNC8, TRUNC16,
COND,
AND, OR, NOT,
EQUAL, NOT_EQ,
LESS, GTR, LESS_EQ, GTR_EQ,
NEXT, NEXT_N, COPY_NEXT,
PUT_GLYPH_8BIT_OBS, PUT_SUBS_8BIT_OBS, PUT_COPY,
INSERT, DELETE,
ASSOC,
CNTXT_ITEM,
ATTR_SET, ATTR_ADD, ATTR_SUB,
ATTR_SET_SLOT,
IATTR_SET_SLOT,
PUSH_SLOT_ATTR, PUSH_GLYPH_ATTR_OBS,
PUSH_GLYPH_METRIC, PUSH_FEAT,
PUSH_ATT_TO_GATTR_OBS, PUSH_ATT_TO_GLYPH_METRIC,
PUSH_ISLOT_ATTR,
PUSH_IGLYPH_ATTR, // not implemented
POP_RET, RET_ZERO, RET_TRUE,
IATTR_SET, IATTR_ADD, IATTR_SUB,
PUSH_PROC_STATE, PUSH_VERSION,
PUT_SUBS, PUT_SUBS2, PUT_SUBS3,
PUT_GLYPH, PUSH_GLYPH_ATTR, PUSH_ATT_TO_GLYPH_ATTR,
BITOR, BITAND, BITNOT,
BITSET, SET_FEAT,
MAX_OPCODE,
// private opcodes for internal use only, comes after all other on disk opcodes
TEMP_COPY = MAX_OPCODE
};
struct opcode_t
{
instr impl[2];
uint8 param_sz;
char name[MAX_NAME_LEN];
};
class Machine
{
public:
typedef int32 stack_t;
static size_t const STACK_ORDER = 10,
STACK_MAX = 1 << STACK_ORDER,
STACK_GUARD = 2;
class Code;
enum status_t {
finished = 0,
stack_underflow,
stack_not_empty,
stack_overflow,
slot_offset_out_bounds,
died_early
};
Machine(SlotMap &) throw();
static const opcode_t * getOpcodeTable() throw();
CLASS_NEW_DELETE;
SlotMap & slotMap() const throw();
status_t status() const throw();
// operator bool () const throw();
private:
void check_final_stack(const stack_t * const sp);
stack_t run(const instr * program, const byte * data,
slotref * & map) HOT;
SlotMap & _map;
stack_t _stack[STACK_MAX + 2*STACK_GUARD];
status_t _status;
};
inline Machine::Machine(SlotMap & map) throw()
: _map(map), _status(finished)
{
// Initialise stack guard +1 entries as the stack pointer points to the
// current top of stack, hence the first push will never write entry 0.
// Initialising the guard space like this is unnecessary and is only
// done to keep valgrind happy during fuzz testing. Hopefully loop
// unrolling will flatten this.
for (size_t n = STACK_GUARD + 1; n; --n) _stack[n-1] = 0;
}
inline SlotMap& Machine::slotMap() const throw()
{
return _map;
}
inline Machine::status_t Machine::status() const throw()
{
return _status;
}
inline void Machine::check_final_stack(const stack_t * const sp)
{
if (_status != finished) return;
stack_t const * const base = _stack + STACK_GUARD,
* const limit = base + STACK_MAX;
if (sp < base) _status = stack_underflow; // This should be impossible now.
else if (sp >= limit) _status = stack_overflow; // So should this.
else if (sp != base) _status = stack_not_empty;
}
} // namespace vm
} // namespace graphite2
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