scummvm/engines/saga2/code.h
2022-10-27 13:58:18 +02:00

371 lines
12 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*
* Based on the original sources
* Faery Tale II -- The Halls of the Dead
* (c) 1993-1996 The Wyrmkeep Entertainment Co.
*/
#ifndef SAGA2_CODE_H
#define SAGA2_CODE_H
namespace Saga2 {
// types of operations for code generation
// note that the macros listed below depend on the ordering of this
// table to determine things like unary-op, binary-op, etc.
enum op_types {
kOpUndefined = 0,
// internal operations
kOpNextblock, // continue execution at next block
kOpDup, // duplicate 16-bit value on stack
kOpDrop, // drop 16-bit value on stack
// primary values
kOpZero, // push a zero on the stack
kOpOne, // push a one on the stack
kOpConstint, // constant integer
kOpConstid, // constant id reference
kOpStrlit, // string literal
kOpSym, // symbol address
kOpSymref, // symbol contents
kOpClassref, // reference to "this"
kOpDeref, // dereference of an ID
// references within this module
kOpGetflag, // read from flag bit (mode)
kOpGetbyte, // read from byte field (mode)
kOpGetint, // read from integer field (mode)
kOpGetstr, // read from string field (mode)
kOpGetid, // read from id field (mode)
kOpPutflag, // put to flag bit (mode)
kOpPutbyte, // put to byte field (mode)
kOpPutint, // put to integer field (mode)
kOpPutstr, // put to string field (mode)
kOpPutid, // put to id field (mode)
kOpPea, // push effective address onto stack
// 'void' versions consume their arguments
kOpPutflagV, // put to flag bit (mode)
kOpPutbyteV, // put to byte field (mode)
kOpPutintV, // put to integer field (mode)
kOpPutstrV, // put to string field (mode)
kOpPutidV, // put to id field (mode)
// function call
kOpCallNear, // call function in same segment
kOpCallFar, // call function in other segment
kOpCcall, // call C function
kOpCcallV, // call C function ()
kOpCallMember, // call member function
kOpCallMemberV, // call member function ()
kOpEnter, // enter a function
kOpReturn, // return from function
kOpReturn_v, // return nothing from function
// branches
kOpJmp,
kOpJmpTrueV, // test arg and consume
kOpJmpFalseV, // test arg and consume
kOpJmpTrue, // test arg and don't consume
kOpJmpDalse, // test arg and don't consume
kOpJmpSwitch, // switch statement (integer)
kOpJmpStrswitch, // switch statement (string)
kOpJmpRandom, // random jump
// unary operators
kOpNegate,
kOpNot,
kOpCompl,
kOpIncV, // increment, don't push
kOpDecV, // decrement, don't push
kOpPostinc,
kOpPostdec,
// arithmetic
kOpAdd,
kOpSub,
kOpMul,
kOpDiv,
kOpMod,
// conditional
kOpConditional,
kOpComma,
// comparison
kOpEq,
kOpNe,
kOpGt,
kOpLt,
kOpGe,
kOpLe,
// string comparison
kOpStrEq,
kOpStrNe,
kOpStrGt,
kOpStrLt,
kOpStrGe,
kOpStrLe,
// shift
kOpRsh,
kOpLsh,
// bitwise
kOpAnd,
kOpOr,
kOpXor,
// logical
kOpLand,
kOpLor,
kOpLxor,
// string functions
kOpStrcat, // string concatenation
kOpStrformat, // string formatting
// assignment operators -- none of these are actually compiled into
// code (they become get/put type operations)
kOpAssign,
// none of these are even used currently...
kOpAsplus,
kOpAsminus,
kOpAstimes,
kOpAsdiv,
kOpAsmod,
kOpAsrshift,
kOpAslshift,
kOpAsand,
kOpAsor,
// Special ops
kOpSpeak,
kOpDialogBegin,
kOpDialogEnd,
kOpReply,
kOpAnimate,
// New opcodes
kOpJmp_seedrandom, // seeded random jump
kOpSymrefX, // get the export number of the symbol
kOpLast /* about 90 so far */
};
// addressing modes for get and put
enum addr_types {
// Offset reference to the thread structure
skAddrThread = 0,
// Offset reference to the stack
skAddrStack,
// Implicit reference to the currently executing segment
skAddrNear,
// Implicit reference to data segment
skAddrData,
// This addressing mode references any external segment
// using a 16-bit segment number and a 16-bit segment offset
// which immediately follow the instruction.
skAddrFar,
// This addressing mode is used for segment-array addressing
// it's a 16-bit segment followed by a 16-bit object number,
// followed by a (byte or bit) offset within the object
skAddrArray,
// This addressing mode uses a 16-bit segment number
// and a 16-bit offset which have been put on the stack.
// skAddrIndirect, // use SEG:offset on stack
// skAddrIndirectIndex, // use SEG:index:offset on stack
// This addressing mode is used for dereferencing objects.
// It consists of an _embedded_ address for retrieving the
// object number, followed by a 16-bit segment number for
// the dereferenced objects, followed by a 16-bit index
// into the dereferenced object.
// REM: We also need a "far deref" for computing the
// dereferenced object's segment number.
skAddrDeref,
// Addressing mode used for class member functions. It
// specified that the address is relative to whatever
// object the 1st argument is referrring to.
skAddrThis // relative to arg 1
};
#define IS_CONST(x) ((x) >= kOpConstint && (x) <= kOpConststr)
#define IS_ADDRESS(x) ((x) == kOpSym)
#define IS_UNOP(x) ((x) >= kOpNegate && (x) <= kOpPostdec)
#define IS_BINOP(x) ((x) >= kOpAdd && (x) <= kOpStrcat)
#define IS_ASOP(x) ((x) >= kOpAssign && (x) <= kOpAsor)
// #define IS_UNOP2(x) ((x) == kOpGetarray || (x) == kOpPutarray)
// #define CONST(op) ((op) >= kOpConstflag && (op) <= kOpConststr)
// Flags for special statements
#define SPEAKF_NOANIMATE (1<<0) // speaker should animate
#define SPEAKF_ASYNC (1<<1) // async speech.
#define REPLYF_ONCE (1<<0) // 'once' flag
#define REPLYF_SUMMARY (1<<1) // response is only a summary
#define REPLYF_CONDITION (1<<2) // response has a condition
#define ANIMATEF_REPEAT (1<<0)
// BasicBlock describes a block of generated code
#ifdef COMPILE_H
typedef struct _BasicBlock {
struct _BasicBlock *next; // pointer to next block
short label; // label for this block
struct _BasicBlock *from[2], // where we could have come from
*jumpto, // where to go if jump
*fallto; // where to go if fall through
struct _Statement *first_st, // statement list for this bblock
*last_st; // it's a circular list
ENode *test_expr; // test expression for jump
char in_flags, // flags for entering this block
jump_type; // where to go after this block
uint16 start_offset, // offset in module of this block
jump_offset; // offset of module of jump at end
int16 source_file, // source line of statement
source_line; // source file of statement
} BasicBlock;
// Various flags for the block
#define BBLOCK_CLABEL (1<<0) /* bblock begins with a 'C' label */
#define BBLOCK_INTLABEL (1<<1) /* bblock begins with internal label */
#define BBLOCK_FIRST (1<<2) /* first bblock in the function */
#define BBLOCK_MANY (1<<3) /* many guys jump to here */
#define BBLOCK_CASE (1<<4) /* case stmts might not have 'from' ptr */
// Jump types
enum jump_types {
kJumpNever = 0, /* never jump */
kJumpFalse, /* jump on expression if false */
kJumpTrue, /* jump on expression if true */
kJumpAlways, /* jump always */
kJumpCjump, /* 'c' goto stm, jumpto is a label # */
kJumpReturn, /* block ends with a 'return' statement */
kJumpSwitch, /* jumps to lots of places */
};
#endif
/*
// Module describes all the code associated with a particular
// compilation unit.
struct Module {
uint16 exportCount, // number of symbols exported
importCount; // number of symbols imported
uint16 exportOffset, // start of export table
importOffset; // start of import table
// Q: Should ModuleName be somewhere else, like in the main program?
uint16 staticSize; // size of static data
uint16 stringOffset; // unused in this version
// int16 moduleName; // offset to name of module
// Followed by list of exports
// Followed by list of imports
// Followed by symbol names, each NULL-terminated
// Followed by actual code blocks
};
// Exports: Each Export contains the offset to find the name of
// the object. After that is the offset to find the object itself.
// The first Export is always the module entry point
struct ModuleExport { // an exported symbol
uint16 symbolOffset, // offset in module of symbol name
objectOffset; // where to find object
};
// Imports: Each Import contains the offset to find the name of
// the object. After that is a blank pointer, which will be filled
// in with the real address of the object. When addressing the
// imported object, the code in this module will refer to this
// ModuleImport entry, and indirectly locate the referenced object.
struct ModuleImport { // a module xref
uint16 symbolOffset; // where, from here, to find name
void *objectPointer; // NULL pointer, filled in on load
};
*/
} // end of namespace Saga2
#endif