/* 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 2 * 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, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. * * $URL$ * $Id$ * */ #include "common/debug.h" #include "common/stack.h" #include "sci/sci.h" #include "sci/debug.h" // for g_debug_weak_validations #include "sci/resource.h" #include "sci/engine/state.h" #include "sci/engine/intmap.h" #include "sci/engine/kernel.h" #include "sci/engine/kernel_types.h" #include "sci/engine/seg_manager.h" #include "sci/engine/gc.h" #include "sci/sfx/misc.h" // for sfx_reset_player namespace Sci { reg_t NULL_REG = {0, 0}; //#define VM_DEBUG_SEND #undef STRICT_SEND // Disallows variable sends with more than one parameter #undef STRICT_READ // Disallows reading from out-of-bounds parameters and locals int script_abort_flag = 0; // Set to 1 to abort execution // FIXME: Avoid non-const global vars int script_step_counter = 0; // Counts the number of steps executed // FIXME: Avoid non-const global vars int script_gc_interval = GC_INTERVAL; // Number of steps in between gcs // FIXME: Avoid non-const global vars static bool breakpointFlag = false; // FIXME: Avoid non-const global vars static reg_t _dummy_register; // FIXME: Avoid non-const global vars // validation functionality #ifndef DISABLE_VALIDATIONS static reg_t &validate_property(Object *obj, int index) { if (!obj) { debugC(2, kDebugLevelVM, "[VM] Sending to disposed object!\n"); _dummy_register = NULL_REG; return _dummy_register; } if (index < 0 || (uint)index >= obj->_variables.size()) { debugC(2, kDebugLevelVM, "[VM] Invalid property #%d (out of [0..%d]) requested!\n", index, obj->_variables.size()); _dummy_register = NULL_REG; return _dummy_register; } return obj->_variables[index]; } static StackPtr validate_stack_addr(EngineState *s, StackPtr sp) { if (sp >= s->stack_base && sp < s->stack_top) return sp; error("[VM] Stack index %d out of valid range [%d..%d]\n", (int)(sp - s->stack_base), 0, (int)(s->stack_top - s->stack_base - 1)); return 0; } static int validate_arithmetic(reg_t reg) { if (reg.segment) { if (g_debug_weak_validations) warning("[VM] Attempt to read arithmetic value from non-zero segment [%04x]\n", reg.segment); else error("[VM] Attempt to read arithmetic value from non-zero segment [%04x]\n", reg.segment); return 0; } return reg.offset; } static int signed_validate_arithmetic(reg_t reg) { if (reg.segment) { if (g_debug_weak_validations) warning("[VM] Attempt to read arithmetic value from non-zero segment [%04x]\n", reg.segment); else error("[VM] Attempt to read arithmetic value from non-zero segment [%04x]\n", reg.segment); return 0; } if (reg.offset&0x8000) return (signed)(reg.offset) - 65536; else return reg.offset; } static int validate_variable(reg_t *r, reg_t *stack_base, int type, int max, int index, int line) { const char *names[4] = {"global", "local", "temp", "param"}; if (index < 0 || index >= max) { char txt[200]; char tmp[40]; sprintf(txt, "[VM] validate_variable(): Attempt to use invalid %s variable %04x ", names[type], index); if (max == 0) strcat(txt, "(variable type invalid)"); else { sprintf(tmp, "(out of range [%d..%d])", 0, max - 1); strcat(txt, tmp); } if (g_debug_weak_validations) warning(txt); else error(txt); #ifdef STRICT_READ return 1; #else // !STRICT_READ if (type == VAR_PARAM || type == VAR_TEMP) { int total_offset = r - stack_base; if (total_offset < 0 || total_offset >= VM_STACK_SIZE) { sciprintf("[VM] Access would be outside even of the stack (%d); access denied\n", total_offset); return 1; } else { sciprintf("[VM] Access within stack boundaries; access granted.\n"); return 0; } } #endif } return 0; } static reg_t validate_read_var(reg_t *r, reg_t *stack_base, int type, int max, int index, int line, reg_t default_value) { if (!validate_variable(r, stack_base, type, max, index, line)) return r[index]; else return default_value; } static void validate_write_var(reg_t *r, reg_t *stack_base, int type, int max, int index, int line, reg_t value) { if (!validate_variable(r, stack_base, type, max, index, line)) r[index] = value; } # define ASSERT_ARITHMETIC(v) validate_arithmetic(v) #else // Non-validating alternatives # define validate_stack_addr(s, sp) sp # define validate_arithmetic(r) ((r).offset) # define signed_validate_arithmetic(r) ((int) ((r).offset) & 0x8000 ? (signed) ((r).offset) - 65536 : ((r).offset)) # define validate_variable(r, sb, t, m, i, l) # define validate_read_var(r, sb, t, m, i, l) ((r)[i]) # define validate_write_var(r, sb, t, m, i, l, v) ((r)[i] = (v)) # define validate_property(o, p) ((o)->_variables[p]) # define ASSERT_ARITHMETIC(v) (v).offset #endif #define READ_VAR(type, index, def) validate_read_var(variables[type], s->stack_base, type, variables_max[type], index, __LINE__, def) #define WRITE_VAR(type, index, value) validate_write_var(variables[type], s->stack_base, type, variables_max[type], index, __LINE__, value) #define WRITE_VAR16(type, index, value) WRITE_VAR(type, index, make_reg(0, value)); #define ACC_ARITHMETIC_L(op) make_reg(0, (op validate_arithmetic(s->r_acc))) #define ACC_AUX_LOAD() aux_acc = signed_validate_arithmetic(s->r_acc) #define ACC_AUX_STORE() s->r_acc = make_reg(0, aux_acc) #define OBJ_PROPERTY(o, p) (validate_property(o, p)) int script_error(EngineState *s, const char *file, int line, const char *reason) { error("Script error in file %s, line %d: %s\n", file, line, reason); return 0; } #define CORE_ERROR(area, msg) script_error(s, "[" area "] " __FILE__, __LINE__, msg) reg_t get_class_address(EngineState *s, int classnr, int lock, reg_t caller) { if (NULL == s) { warning("vm.c: get_class_address(): NULL passed for \"s\""); return NULL_REG; } if (classnr < 0 || (int)s->_classtable.size() <= classnr || s->_classtable[classnr].script < 0) { error("[VM] Attempt to dereference class %x, which doesn't exist (max %x)", classnr, s->_classtable.size()); return NULL_REG; } else { Class *the_class = &s->_classtable[classnr]; if (!the_class->reg.segment) { script_get_segment(s, the_class->script, lock); if (!the_class->reg.segment) { error("[VM] Trying to instantiate class %x by instantiating script 0x%x (%03d) failed;" " Entering debugger.", classnr, the_class->script, the_class->script); return NULL_REG; } } else if (caller.segment != the_class->reg.segment) s->seg_manager->getScript(the_class->reg.segment)->incrementLockers(); return the_class->reg; } } // Operating on the stack // 16 bit: #define PUSH(v) PUSH32(make_reg(0, v)) #define POP() (validate_arithmetic(POP32())) // 32 bit: #define PUSH32(a) (*(validate_stack_addr(s, (xs->sp)++)) = (a)) #define POP32() (*(validate_stack_addr(s, --(xs->sp)))) // Getting instruction parameters #define GET_OP_BYTE() ((uint8)code_buf[(xs->addr.pc.offset)++]) #define GET_OP_WORD() (READ_LE_UINT16(code_buf + ((xs->addr.pc.offset) += 2) - 2)) #define GET_OP_FLEX() ((opcode & 1)? GET_OP_BYTE() : GET_OP_WORD()) #define GET_OP_SIGNED_BYTE() ((int8)(code_buf[(xs->addr.pc.offset)++])) #define GET_OP_SIGNED_WORD() (((int16)READ_LE_UINT16(code_buf + ((xs->addr.pc.offset) += 2) - 2))) #define GET_OP_SIGNED_FLEX() ((opcode & 1)? GET_OP_SIGNED_BYTE() : GET_OP_SIGNED_WORD()) ExecStack *execute_method(EngineState *s, uint16 script, uint16 pubfunct, StackPtr sp, reg_t calling_obj, uint16 argc, StackPtr argp) { int seg = s->seg_manager->segGet(script); Script *scr = s->seg_manager->getScriptIfLoaded(seg); if (!scr) // Script not present yet? seg = script_instantiate(s, script); else scr->unmarkDeleted(); int temp = s->seg_manager->validateExportFunc(pubfunct, seg); if (!temp) { error("Request for invalid exported function 0x%x of script 0x%x\n", pubfunct, script); return NULL; } // Check if a breakpoint is set on this method if (s->have_bp & BREAK_EXPORT) { Breakpoint *bp; uint32 bpaddress; bpaddress = (script << 16 | pubfunct); bp = s->bp_list; while (bp) { if (bp->type == BREAK_EXPORT && bp->data.address == bpaddress) { sciprintf("Break on script %d, export %d\n", script, pubfunct); breakpointFlag = true; break; } bp = bp->next; } } return add_exec_stack_entry(s, make_reg(seg, temp), sp, calling_obj, argc, argp, -1, calling_obj, s->_executionStack.size()-1, seg); } static void _exec_varselectors(EngineState *s) { // Executes all varselector read/write ops on the TOS while (!s->_executionStack.empty() && s->_executionStack.back().type == EXEC_STACK_TYPE_VARSELECTOR) { ExecStack &xs = s->_executionStack.back(); // varselector access? if (xs.argc) { // write? *(xs.addr.varp) = xs.variables_argp[1]; } else // No, read s->r_acc = *(xs.addr.varp); s->_executionStack.pop_back(); } } ExecStack *send_selector(EngineState *s, reg_t send_obj, reg_t work_obj, StackPtr sp, int framesize, StackPtr argp) { // send_obj and work_obj are equal for anything but 'super' // Returns a pointer to the TOS exec_stack element assert(s); reg_t *varp; reg_t funcp; int selector; int argc; int origin = s->_executionStack.size()-1; // Origin: Used for debugging int print_send_action = 0; // We return a pointer to the new active ExecStack // The selector calls we catch are stored below: Common::Stack sendCalls; while (framesize > 0) { selector = validate_arithmetic(*argp++); argc = validate_arithmetic(*argp); if (argc > 0x800) { // More arguments than the stack could possibly accomodate for CORE_ERROR("SEND", "More than 0x800 arguments to function call\n"); return NULL; } // Check if a breakpoint is set on this method if (s->have_bp & BREAK_SELECTOR) { Breakpoint *bp; char method_name [256]; sprintf(method_name, "%s::%s", obj_get_name(s, send_obj), s->_kernel->getSelectorName(selector).c_str()); bp = s->bp_list; while (bp) { int cmplen = strlen(bp->data.name); if (bp->data.name[cmplen - 1] != ':') cmplen = 256; if (bp->type == BREAK_SELECTOR && !strncmp(bp->data.name, method_name, cmplen)) { sciprintf("Break on %s (in [%04x:%04x])\n", method_name, PRINT_REG(send_obj)); print_send_action = 1; breakpointFlag = true; break; } bp = bp->next; } } #ifdef VM_DEBUG_SEND sciprintf("Send to %04x:%04x, selector %04x (%s):", PRINT_REG(send_obj), selector, s->_selectorNames[selector].c_str()); #endif // VM_DEBUG_SEND switch (lookup_selector(s, send_obj, selector, &varp, &funcp)) { case kSelectorNone: // WORKAROUND: LSL6 tries to access the invalid 'keep' selector of the game object. // FIXME: Find out if this is a game bug. if ((s->_gameName == "LSL6") && (selector == 0x18c)) { debug("LSL6 detected, continuing..."); break; } error("Send to invalid selector 0x%x of object at %04x:%04x\n", 0xffff & selector, PRINT_REG(send_obj)); break; case kSelectorVariable: #ifdef VM_DEBUG_SEND sciprintf("Varselector: "); if (argc) sciprintf("Write %04x:%04x\n", PRINT_REG(argp[1])); else sciprintf("Read\n"); #endif // VM_DEBUG_SEND switch (argc) { case 0: // Read selector if (print_send_action) { sciprintf("[read selector]\n"); print_send_action = 0; } // fallthrough case 1: #ifndef STRICT_SEND default: #endif { // Argument is supplied -> Selector should be set if (print_send_action) { reg_t oldReg = *varp; reg_t newReg = argp[1]; sciprintf("[write to selector: change %04x:%04x to %04x:%04x]\n", PRINT_REG(oldReg), PRINT_REG(newReg)); print_send_action = 0; } CallsStruct call; call.address.var = varp; // register the call call.argp = argp; call.argc = argc; call.selector = selector; call.type = EXEC_STACK_TYPE_VARSELECTOR; // Register as a varselector sendCalls.push(call); } break; #ifdef STRICT_SEND default: sciprintf("Send error: Variable selector %04x in %04x:%04x called with %04x params\n", selector, PRINT_REG(send_obj), argc); script_debug_flag = 1; // Enter debug mode g_debug_seeking = g_debug_step_running = 0; #endif } break; case kSelectorMethod: #ifdef VM_DEBUG_SEND sciprintf("Funcselector("); for (int i = 0; i < argc; i++) { sciprintf(PREG, PRINT_REG(argp[i+1])); if (i + 1 < argc) sciprintf(", "); } sciprintf(") at %04x:%04x\n", PRINT_REG(funcp)); #endif // VM_DEBUG_SEND if (print_send_action) { sciprintf("[invoke selector]\n"); print_send_action = 0; } CallsStruct call; call.address.func = funcp; // register call call.argp = argp; call.argc = argc; call.selector = selector; call.type = EXEC_STACK_TYPE_CALL; call.sp = sp; sp = CALL_SP_CARRY; // Destroy sp, as it will be carried over sendCalls.push(call); break; } // switch(lookup_selector()) framesize -= (2 + argc); argp += argc + 1; } // Iterate over all registered calls in the reverse order. This way, the first call is // placed on the TOS; as soon as it returns, it will cause the second call to be executed. while (!sendCalls.empty()) { CallsStruct call = sendCalls.pop(); if (call.type == EXEC_STACK_TYPE_VARSELECTOR) // Write/read variable? add_exec_stack_varselector(s, work_obj, call.argc, call.argp, call.selector, call.address.var, origin); else add_exec_stack_entry(s, call.address.func, call.sp, work_obj, call.argc, call.argp, call.selector, send_obj, origin, SCI_XS_CALLEE_LOCALS); } _exec_varselectors(s); if (s->_executionStack.empty()) return NULL; return &(s->_executionStack.back()); } ExecStack *add_exec_stack_varselector(EngineState *s, reg_t objp, int argc, StackPtr argp, Selector selector, reg_t *address, int origin) { ExecStack *xstack = add_exec_stack_entry(s, NULL_REG, address, objp, argc, argp, selector, objp, origin, SCI_XS_CALLEE_LOCALS); // Store selector address in sp xstack->addr.varp = address; xstack->type = EXEC_STACK_TYPE_VARSELECTOR; return xstack; } ExecStack *add_exec_stack_entry(EngineState *s, reg_t pc, StackPtr sp, reg_t objp, int argc, StackPtr argp, Selector selector, reg_t sendp, int origin, SegmentId locals_segment) { // Returns new TOS element for the execution stack // locals_segment may be -1 if derived from the called object //sciprintf("Exec stack: [%d/%d], origin %d, at %p\n", s->execution_stack_pos, s->_executionStack.size(), origin, s->execution_stack); ExecStack xstack; xstack.objp = objp; if (locals_segment != SCI_XS_CALLEE_LOCALS) xstack.local_segment = locals_segment; else xstack.local_segment = pc.segment; xstack.sendp = sendp; xstack.addr.pc = pc; xstack.fp = xstack.sp = sp; xstack.argc = argc; xstack.variables_argp = argp; // Parameters *argp = make_reg(0, argc); // SCI code relies on the zeroeth argument to equal argc // Additional debug information xstack.selector = selector; xstack.origin = origin; xstack.type = EXEC_STACK_TYPE_CALL; // Normal call s->_executionStack.push_back(xstack); return &(s->_executionStack.back()); } #ifdef DISABLE_VALIDATONS # define kernel_matches_signature(a, b, c, d) 1 #endif void vm_handle_fatal_error(EngineState *s, int line, const char *file) { error("Fatal VM error in %s, L%d; aborting...", file, line); } static Script *script_locate_by_segment(EngineState *s, SegmentId seg) { return s->seg_manager->getScriptIfLoaded(seg); } static reg_t pointer_add(EngineState *s, reg_t base, int offset) { MemObject *mobj = GET_SEGMENT_ANY(*s->seg_manager, base.segment); if (!mobj) { error("[VM] Error: Attempt to add %d to invalid pointer %04x:%04x!", offset, PRINT_REG(base)); return NULL_REG; } switch (mobj->getType()) { case MEM_OBJ_LOCALS: base.offset += 2 * offset; return base; case MEM_OBJ_SCRIPT: case MEM_OBJ_STACK: case MEM_OBJ_DYNMEM: base.offset += offset; return base; break; default: sciprintf("[VM] Error: Attempt to add %d to pointer %04x:%04x: Pointer arithmetics of this type unsupported!", offset, PRINT_REG(base)); return NULL_REG; } } static void gc_countdown(EngineState *s) { if (s->gc_countdown-- <= 0) { s->gc_countdown = script_gc_interval; run_gc(s); } } static const byte _fake_return_buffer[2] = {op_ret << 1, op_ret << 1}; void run_vm(EngineState *s, int restoring) { assert(s); reg_t *variables[4]; // global, local, temp, param, as immediate pointers reg_t *variables_base[4]; // Used for referencing VM ops SegmentId variables_seg[4]; // Same as above, contains segment IDs #ifndef DISABLE_VALIDATIONS int variables_max[4]; // Max. values for all variables unsigned int code_buf_size = 0 ; // (Avoid spurious warning) #endif int temp; int16 aux_acc; // Auxiliary 16 bit accumulator reg_t r_temp; // Temporary register StackPtr s_temp; // Temporary stack pointer int16 opparams[4]; // opcode parameters int restadjust = s->r_amp_rest; // &rest adjusts the parameter count by this value // Current execution data: ExecStack *xs = &(s->_executionStack.back()); ExecStack *xs_new = NULL; Object *obj = obj_get(s, xs->objp); Script *local_script = script_locate_by_segment(s, xs->local_segment); int old_execution_stack_base = s->execution_stack_base; // Used to detect the stack bottom, for "physical" returns const byte *code_buf = NULL; // (Avoid spurious warning) if (!local_script) { script_error(s, __FILE__, __LINE__, "Program Counter gone astray"); return; } if (!restoring) s->execution_stack_base = s->_executionStack.size()-1; #ifndef DISABLE_VALIDATIONS // Initialize maximum variable count if (s->script_000->locals_block) variables_max[VAR_GLOBAL] = s->script_000->locals_block->_locals.size(); else variables_max[VAR_GLOBAL] = 0; #endif variables_seg[VAR_GLOBAL] = s->script_000->locals_segment; variables_seg[VAR_TEMP] = variables_seg[VAR_PARAM] = s->stack_segment; variables_base[VAR_TEMP] = variables_base[VAR_PARAM] = s->stack_base; // SCI code reads the zeroeth argument to determine argc if (s->script_000->locals_block) variables_base[VAR_GLOBAL] = variables[VAR_GLOBAL] = s->script_000->locals_block->_locals.begin(); else variables_base[VAR_GLOBAL] = variables[VAR_GLOBAL] = NULL; s->_executionStackPosChanged = true; // Force initialization while (1) { byte opcode; int old_pc_offset; StackPtr old_sp; byte opnumber; int var_type; // See description below int var_number; old_pc_offset = xs->addr.pc.offset; old_sp = xs->sp; if (s->_executionStackPosChanged) { Script *scr; xs = &(s->_executionStack.back()); s->_executionStackPosChanged = false; scr = script_locate_by_segment(s, xs->addr.pc.segment); if (!scr) { // No script? Implicit return via fake instruction buffer warning("Running on non-existant script in segment %x", xs->addr.pc.segment); code_buf = _fake_return_buffer; #ifndef DISABLE_VALIDATIONS code_buf_size = 2; #endif xs->addr.pc.offset = 1; scr = NULL; obj = NULL; } else { obj = obj_get(s, xs->objp); code_buf = scr->buf; #ifndef DISABLE_VALIDATIONS code_buf_size = scr->buf_size; #endif local_script = script_locate_by_segment(s, xs->local_segment); if (!local_script) { warning("Could not find local script from segment %x", xs->local_segment); local_script = NULL; variables_base[VAR_LOCAL] = variables[VAR_LOCAL] = NULL; #ifndef DISABLE_VALIDATIONS variables_max[VAR_LOCAL] = 0; #endif } else { variables_seg[VAR_LOCAL] = local_script->locals_segment; if (local_script->locals_block) variables_base[VAR_LOCAL] = variables[VAR_LOCAL] = local_script->locals_block->_locals.begin(); else variables_base[VAR_LOCAL] = variables[VAR_LOCAL] = NULL; #ifndef DISABLE_VALIDATIONS if (local_script->locals_block) variables_max[VAR_LOCAL] = local_script->locals_block->_locals.size(); else variables_max[VAR_LOCAL] = 0; variables_max[VAR_TEMP] = xs->sp - xs->fp; variables_max[VAR_PARAM] = xs->argc + 1; #endif } variables[VAR_TEMP] = xs->fp; variables[VAR_PARAM] = xs->variables_argp; } } if (script_abort_flag) return; // Emergency // TODO: re-enable this #if 0 // Debug if this has been requested: if (script_debug_flag || sci_debug_flags) { script_debug(s, &(xs->addr.pc), &(xs->sp), &(xs->fp), &(xs->objp), &restadjust, variables_seg, variables, variables_base, #ifdef DISABLE_VALIDATIONS NULL, #else variables_max, #endif breakpointFlag); breakpointFlag = false; } #endif #ifndef DISABLE_VALIDATIONS if (xs->sp < xs->fp) script_error(s, "[VM] "__FILE__, __LINE__, "Stack underflow"); variables_max[VAR_TEMP] = xs->sp - xs->fp; if (xs->addr.pc.offset >= code_buf_size) script_error(s, "[VM] "__FILE__, __LINE__, "Program Counter gone astray"); #endif opcode = GET_OP_BYTE(); // Get opcode opnumber = opcode >> 1; for (temp = 0; g_opcode_formats[opnumber][temp]; temp++) switch (g_opcode_formats[opnumber][temp]) { case Script_Byte: opparams[temp] = GET_OP_BYTE(); break; case Script_SByte: opparams[temp] = GET_OP_SIGNED_BYTE(); break; case Script_Word: opparams[temp] = GET_OP_WORD(); break; case Script_SWord: opparams[temp] = GET_OP_SIGNED_WORD(); break; case Script_Variable: case Script_Property: case Script_Local: case Script_Temp: case Script_Global: case Script_Param: opparams[temp] = GET_OP_FLEX(); break; case Script_SVariable: case Script_SRelative: opparams[temp] = GET_OP_SIGNED_FLEX(); break; case Script_Offset: opparams[temp] = GET_OP_FLEX(); break; case Script_None: case Script_End: break; case Script_Invalid: default: error("opcode %02x: Invalid", opcode); } // TODO: Replace the following by an opcode table, and several methods for // each opcode. switch (opnumber) { case 0x00: // bnot s->r_acc = ACC_ARITHMETIC_L(0xffff ^ /*acc*/); break; case 0x01: // add r_temp = POP32(); if (r_temp.segment || s->r_acc.segment) { reg_t r_ptr = NULL_REG; int offset; // Pointer arithmetics! if (s->r_acc.segment) { if (r_temp.segment) { error("Attempt to add two pointers, stack=%04x:%04x and acc=%04x:%04x", PRINT_REG(r_temp), PRINT_REG(s->r_acc)); offset = 0; } else { r_ptr = s->r_acc; offset = r_temp.offset; } } else { r_ptr = r_temp; offset = s->r_acc.offset; } s->r_acc = pointer_add(s, r_ptr, offset); } else s->r_acc = make_reg(0, r_temp.offset + s->r_acc.offset); break; case 0x02: // sub r_temp = POP32(); if (r_temp.segment || s->r_acc.segment) { reg_t r_ptr = NULL_REG; int offset; // Pointer arithmetics! if (s->r_acc.segment) { if (r_temp.segment) { error("Attempt to subtract two pointers, stack=%04x:%04x and acc=%04x:%04x", PRINT_REG(r_temp), PRINT_REG(s->r_acc)); offset = 0; } else { r_ptr = s->r_acc; offset = r_temp.offset; } } else { r_ptr = r_temp; offset = s->r_acc.offset; } s->r_acc = pointer_add(s, r_ptr, -offset); } else s->r_acc = make_reg(0, r_temp.offset - s->r_acc.offset); break; case 0x03: // mul s->r_acc = ACC_ARITHMETIC_L(((int16)POP()) * (int16)/*acc*/); break; case 0x04: // div ACC_AUX_LOAD(); aux_acc = aux_acc != 0 ? ((int16)POP()) / aux_acc : 0; ACC_AUX_STORE(); break; case 0x05: // mod ACC_AUX_LOAD(); aux_acc = aux_acc != 0 ? ((int16)POP()) % aux_acc : 0; ACC_AUX_STORE(); break; case 0x06: // shr s->r_acc = ACC_ARITHMETIC_L(((uint16) POP()) >> /*acc*/); break; case 0x07: // shl s->r_acc = ACC_ARITHMETIC_L(((uint16)POP()) << /*acc*/); break; case 0x08: // xor s->r_acc = ACC_ARITHMETIC_L(POP() ^ /*acc*/); break; case 0x09: // and s->r_acc = ACC_ARITHMETIC_L(POP() & /*acc*/); break; case 0x0a: // or s->r_acc = ACC_ARITHMETIC_L(POP() | /*acc*/); break; case 0x0b: // neg s->r_acc = ACC_ARITHMETIC_L(-/*acc*/); break; case 0x0c: // not s->r_acc = make_reg(0, !(s->r_acc.offset || s->r_acc.segment)); // Must allow pointers to be negated, as this is used for checking whether objects exist break; case 0x0d: // eq? s->r_prev = s->r_acc; r_temp = POP32(); s->r_acc = make_reg(0, r_temp == s->r_acc); // Explicitly allow pointers to be compared break; case 0x0e: // ne? s->r_prev = s->r_acc; r_temp = POP32(); s->r_acc = make_reg(0, r_temp != s->r_acc); // Explicitly allow pointers to be compared break; case 0x0f: // gt? s->r_prev = s->r_acc; s->r_acc = ACC_ARITHMETIC_L((int16)POP() > (int16)/*acc*/); break; case 0x10: // ge? s->r_prev = s->r_acc; s->r_acc = ACC_ARITHMETIC_L((int16)POP() >= (int16)/*acc*/); break; case 0x11: // lt? s->r_prev = s->r_acc; s->r_acc = ACC_ARITHMETIC_L((int16)POP() < (int16)/*acc*/); break; case 0x12: // le? s->r_prev = s->r_acc; s->r_acc = ACC_ARITHMETIC_L((int16)POP() <= (int16)/*acc*/); break; case 0x13: // ugt? s->r_prev = s->r_acc; r_temp = POP32(); s->r_acc = make_reg(0, (r_temp.segment == s->r_acc.segment) && r_temp.offset > s->r_acc.offset); break; case 0x14: // uge? s->r_prev = s->r_acc; r_temp = POP32(); s->r_acc = make_reg(0, (r_temp.segment == s->r_acc.segment) && r_temp.offset >= s->r_acc.offset); break; case 0x15: // ult? s->r_prev = s->r_acc; r_temp = POP32(); s->r_acc = make_reg(0, (r_temp.segment == s->r_acc.segment) && r_temp.offset < s->r_acc.offset); break; case 0x16: // ule? s->r_prev = s->r_acc; r_temp = POP32(); s->r_acc = make_reg(0, (r_temp.segment == s->r_acc.segment) && r_temp.offset <= s->r_acc.offset); break; case 0x17: // bt if (s->r_acc.offset || s->r_acc.segment) xs->addr.pc.offset += opparams[0]; break; case 0x18: // bnt if (!(s->r_acc.offset || s->r_acc.segment)) xs->addr.pc.offset += opparams[0]; break; case 0x19: // jmp xs->addr.pc.offset += opparams[0]; break; case 0x1a: // ldi s->r_acc = make_reg(0, opparams[0]); break; case 0x1b: // push PUSH32(s->r_acc); break; case 0x1c: // pushi PUSH(opparams[0]); break; case 0x1d: // toss xs->sp--; break; case 0x1e: // dup r_temp = xs->sp[-1]; PUSH32(r_temp); break; case 0x1f: { // link int i; for (i = 0; i < opparams[0]; i++) xs->sp[i] = NULL_REG; xs->sp += opparams[0]; break; } case 0x20: { // call int argc = (opparams[1] >> 1) // Given as offset, but we need count + 1 + restadjust; StackPtr call_base = xs->sp - argc; xs->sp[1].offset += restadjust; xs_new = add_exec_stack_entry(s, make_reg(xs->addr.pc.segment, xs->addr.pc.offset + opparams[0]), xs->sp, xs->objp, (validate_arithmetic(*call_base)) + restadjust, call_base, NULL_SELECTOR, xs->objp, s->_executionStack.size()-1, xs->local_segment); restadjust = 0; // Used up the &rest adjustment xs->sp = call_base; s->_executionStackPosChanged = true; break; } case 0x21: // callk gc_countdown(s); xs->sp -= (opparams[1] >> 1) + 1; if (!(s->_flags & GF_SCI0_OLD)) { xs->sp -= restadjust; s->r_amp_rest = 0; // We just used up the restadjust, remember? } if (opparams[0] >= (int)s->_kernel->_kernelFuncs.size()) { error("Invalid kernel function 0x%x requested\n", opparams[0]); } else { int argc = ASSERT_ARITHMETIC(xs->sp[0]); if (!(s->_flags & GF_SCI0_OLD)) argc += restadjust; if (s->_kernel->_kernelFuncs[opparams[0]].signature && !kernel_matches_signature(s, s->_kernel->_kernelFuncs[opparams[0]].signature, argc, xs->sp + 1)) { error("[VM] Invalid arguments to kernel call %x\n", opparams[0]); } else { s->r_acc = s->_kernel->_kernelFuncs[opparams[0]].fun(s, opparams[0], argc, xs->sp + 1); } // Call kernel function // Calculate xs again: The kernel function might // have spawned a new VM xs_new = &(s->_executionStack.back()); s->_executionStackPosChanged = true; if (!(s->_flags & GF_SCI0_OLD)) restadjust = s->r_amp_rest; } break; case 0x22: // callb temp = ((opparams[1] >> 1) + restadjust + 1); s_temp = xs->sp; xs->sp -= temp; xs->sp[0].offset += restadjust; xs_new = execute_method(s, 0, opparams[0], s_temp, xs->objp, xs->sp[0].offset, xs->sp); restadjust = 0; // Used up the &rest adjustment if (xs_new) // in case of error, keep old stack s->_executionStackPosChanged = true; break; case 0x23: // calle temp = ((opparams[2] >> 1) + restadjust + 1); s_temp = xs->sp; xs->sp -= temp; xs->sp[0].offset += restadjust; xs_new = execute_method(s, opparams[0], opparams[1], s_temp, xs->objp, xs->sp[0].offset, xs->sp); restadjust = 0; // Used up the &rest adjustment if (xs_new) // in case of error, keep old stack s->_executionStackPosChanged = true; break; case 0x24: // ret do { StackPtr old_sp2 = xs->sp; StackPtr old_fp = xs->fp; ExecStack *old_xs = &(s->_executionStack.back()); if ((int)s->_executionStack.size()-1 == s->execution_stack_base) { // Have we reached the base? s->execution_stack_base = old_execution_stack_base; // Restore stack base s->_executionStack.pop_back(); s->_executionStackPosChanged = true; s->r_amp_rest = restadjust; // Update &rest return; // "Hard" return } if (old_xs->type == EXEC_STACK_TYPE_VARSELECTOR) { // varselector access? if (old_xs->argc) // write? *(old_xs->addr.varp) = old_xs->variables_argp[1]; else // No, read s->r_acc = *(old_xs->addr.varp); } // Not reached the base, so let's do a soft return s->_executionStack.pop_back(); s->_executionStackPosChanged = true; xs = &(s->_executionStack.back()); if (xs->sp == CALL_SP_CARRY // Used in sends to 'carry' the stack pointer || xs->type != EXEC_STACK_TYPE_CALL) { xs->sp = old_sp2; xs->fp = old_fp; } } while (xs->type == EXEC_STACK_TYPE_VARSELECTOR); // Iterate over all varselector accesses s->_executionStackPosChanged = true; xs_new = xs; break; case 0x25: // send s_temp = xs->sp; xs->sp -= ((opparams[0] >> 1) + restadjust); // Adjust stack xs->sp[1].offset += restadjust; xs_new = send_selector(s, s->r_acc, s->r_acc, s_temp, (int)(opparams[0] >> 1) + (uint16)restadjust, xs->sp); if (xs_new && xs_new != xs) s->_executionStackPosChanged = true; restadjust = 0; break; case 0x28: // class s->r_acc = get_class_address(s, (unsigned)opparams[0], SCRIPT_GET_LOCK, xs->addr.pc); break; case 0x2a: // self s_temp = xs->sp; xs->sp -= ((opparams[0] >> 1) + restadjust); // Adjust stack xs->sp[1].offset += restadjust; xs_new = send_selector(s, xs->objp, xs->objp, s_temp, (int)(opparams[0] >> 1) + (uint16)restadjust, xs->sp); if (xs_new && xs_new != xs) s->_executionStackPosChanged = true; restadjust = 0; break; case 0x2b: // super r_temp = get_class_address(s, opparams[0], SCRIPT_GET_LOAD, xs->addr.pc); if (!r_temp.segment) CORE_ERROR("VM", "Invalid superclass in object"); else { s_temp = xs->sp; xs->sp -= ((opparams[1] >> 1) + restadjust); // Adjust stack xs->sp[1].offset += restadjust; xs_new = send_selector(s, r_temp, xs->objp, s_temp, (int)(opparams[1] >> 1) + (uint16)restadjust, xs->sp); if (xs_new && xs_new != xs) s->_executionStackPosChanged = true; restadjust = 0; } break; case 0x2c: // &rest temp = (uint16) opparams[0]; // First argument restadjust = xs->argc - temp + 1; // +1 because temp counts the paramcount while argc doesn't if (restadjust < 0) restadjust = 0; for (; temp <= xs->argc; temp++) PUSH32(xs->variables_argp[temp]); break; case 0x2d: // lea temp = (uint16) opparams[0] >> 1; var_number = temp & 0x03; // Get variable type // Get variable block offset r_temp.segment = variables_seg[var_number]; r_temp.offset = variables[var_number] - variables_base[var_number]; if (temp & 0x08) // Add accumulator offset if requested r_temp.offset += signed_validate_arithmetic(s->r_acc); r_temp.offset += opparams[1]; // Add index r_temp.offset *= sizeof(reg_t); // That's the immediate address now s->r_acc = r_temp; break; case 0x2e: // selfID s->r_acc = xs->objp; break; case 0x30: // pprev PUSH32(s->r_prev); break; case 0x31: // pToa s->r_acc = OBJ_PROPERTY(obj, (opparams[0] >> 1)); break; case 0x32: // aTop OBJ_PROPERTY(obj, (opparams[0] >> 1)) = s->r_acc; break; case 0x33: // pTos PUSH32(OBJ_PROPERTY(obj, opparams[0] >> 1)); break; case 0x34: // sTop OBJ_PROPERTY(obj, (opparams[0] >> 1)) = POP32(); break; case 0x35: // ipToa s->r_acc = OBJ_PROPERTY(obj, (opparams[0] >> 1)); s->r_acc = OBJ_PROPERTY(obj, (opparams[0] >> 1)) = ACC_ARITHMETIC_L(1 + /*acc*/); break; case 0x36: // dpToa s->r_acc = OBJ_PROPERTY(obj, (opparams[0] >> 1)); s->r_acc = OBJ_PROPERTY(obj, (opparams[0] >> 1)) = ACC_ARITHMETIC_L(-1 + /*acc*/); break; case 0x37: // ipTos ASSERT_ARITHMETIC(OBJ_PROPERTY(obj, (opparams[0] >> 1))); temp = ++OBJ_PROPERTY(obj, (opparams[0] >> 1)).offset; PUSH(temp); break; case 0x38: // dpTos ASSERT_ARITHMETIC(OBJ_PROPERTY(obj, (opparams[0] >> 1))); temp = --OBJ_PROPERTY(obj, (opparams[0] >> 1)).offset; PUSH(temp); break; case 0x39: // lofsa s->r_acc.segment = xs->addr.pc.segment; if (s->_version >= SCI_VERSION_1_1) { s->r_acc.offset = opparams[0] + local_script->script_size; } else { if (s->_flags & GF_SCI1_LOFSABSOLUTE) s->r_acc.offset = opparams[0]; else s->r_acc.offset = xs->addr.pc.offset + opparams[0]; } #ifndef DISABLE_VALIDATIONS if (s->r_acc.offset >= code_buf_size) { error("VM: lofsa operation overflowed: %04x:%04x beyond end" " of script (at %04x)\n", PRINT_REG(s->r_acc), code_buf_size); } #endif break; case 0x3a: // lofss r_temp.segment = xs->addr.pc.segment; if (s->_flags & GF_SCI1_LOFSABSOLUTE) r_temp.offset = opparams[0]; else r_temp.offset = xs->addr.pc.offset + opparams[0]; #ifndef DISABLE_VALIDATIONS if (r_temp.offset >= code_buf_size) { error("VM: lofss operation overflowed: %04x:%04x beyond end" " of script (at %04x)\n", PRINT_REG(r_temp), code_buf_size); } #endif PUSH32(r_temp); break; case 0x3b: // push0 PUSH(0); break; case 0x3c: // push1 PUSH(1); break; case 0x3d: // push2 PUSH(2); break; case 0x3e: // pushSelf PUSH32(xs->objp); break; case 0x40: // lag case 0x41: // lal case 0x42: // lat case 0x43: // lap var_type = (opcode >> 1) & 0x3; // Gets the variable type: g, l, t or p var_number = opparams[0]; s->r_acc = READ_VAR(var_type, var_number, s->r_acc); break; case 0x44: // lsg case 0x45: // lsl case 0x46: // lst case 0x47: // lsp var_type = (opcode >> 1) & 0x3; // Gets the variable type: g, l, t or p var_number = opparams[0]; PUSH32(READ_VAR(var_type, var_number, s->r_acc)); break; case 0x48: // lagi case 0x49: // lali case 0x4a: // lati case 0x4b: // lapi var_type = (opcode >> 1) & 0x3; // Gets the variable type: g, l, t or p var_number = opparams[0] + signed_validate_arithmetic(s->r_acc); s->r_acc = READ_VAR(var_type, var_number, s->r_acc); break; case 0x4c: // lsgi case 0x4d: // lsli case 0x4e: // lsti case 0x4f: // lspi var_type = (opcode >> 1) & 0x3; // Gets the variable type: g, l, t or p var_number = opparams[0] + signed_validate_arithmetic(s->r_acc); PUSH32(READ_VAR(var_type, var_number, s->r_acc)); break; case 0x50: // sag case 0x51: // sal case 0x52: // sat case 0x53: // sap var_type = (opcode >> 1) & 0x3; // Gets the variable type: g, l, t or p var_number = opparams[0]; WRITE_VAR(var_type, var_number, s->r_acc); break; case 0x54: // ssg case 0x55: // ssl case 0x56: // sst case 0x57: // ssp var_type = (opcode >> 1) & 0x3; // Gets the variable type: g, l, t or p var_number = opparams[0]; WRITE_VAR(var_type, var_number, POP32()); break; case 0x58: // sagi case 0x59: // sali case 0x5a: // sati case 0x5b: // sapi // Special semantics because it wouldn't really make a whole lot // of sense otherwise, with acc being used for two things // simultaneously... var_type = (opcode >> 1) & 0x3; // Gets the variable type: g, l, t or p var_number = opparams[0] + signed_validate_arithmetic(s->r_acc); WRITE_VAR(var_type, var_number, s->r_acc = POP32()); break; case 0x5c: // ssgi case 0x5d: // ssli case 0x5e: // ssti case 0x5f: // sspi var_type = (opcode >> 1) & 0x3; // Gets the variable type: g, l, t or p var_number = opparams[0] + signed_validate_arithmetic(s->r_acc); WRITE_VAR(var_type, var_number, POP32()); break; case 0x60: // +ag case 0x61: // +al case 0x62: // +at case 0x63: // +ap var_type = (opcode >> 1) & 0x3; // Gets the variable type: g, l, t or p var_number = opparams[0]; s->r_acc = make_reg(0, 1 + validate_arithmetic(READ_VAR(var_type, var_number, s->r_acc))); WRITE_VAR(var_type, var_number, s->r_acc); break; case 0x64: // +sg case 0x65: // +sl case 0x66: // +st case 0x67: // +sp var_type = (opcode >> 1) & 0x3; // Gets the variable type: g, l, t or p var_number = opparams[0]; r_temp = make_reg(0, 1 + validate_arithmetic(READ_VAR(var_type, var_number, s->r_acc))); PUSH32(r_temp); WRITE_VAR(var_type, var_number, r_temp); break; case 0x68: // +agi case 0x69: // +ali case 0x6a: // +ati case 0x6b: // +api var_type = (opcode >> 1) & 0x3; // Gets the variable type: g, l, t or p var_number = opparams[0] + signed_validate_arithmetic(s->r_acc); s->r_acc = make_reg(0, 1 + validate_arithmetic(READ_VAR(var_type, var_number, s->r_acc))); WRITE_VAR(var_type, var_number, s->r_acc); break; case 0x6c: // +sgi case 0x6d: // +sli case 0x6e: // +sti case 0x6f: // +spi var_type = (opcode >> 1) & 0x3; // Gets the variable type: g, l, t or p var_number = opparams[0] + signed_validate_arithmetic(s->r_acc); r_temp = make_reg(0, 1 + validate_arithmetic(READ_VAR(var_type, var_number, s->r_acc))); PUSH32(r_temp); WRITE_VAR(var_type, var_number, r_temp); break; case 0x70: // -ag case 0x71: // -al case 0x72: // -at case 0x73: // -ap var_type = (opcode >> 1) & 0x3; // Gets the variable type: g, l, t or p var_number = opparams[0]; s->r_acc = make_reg(0, -1 + validate_arithmetic(READ_VAR(var_type, var_number, s->r_acc))); WRITE_VAR(var_type, var_number, s->r_acc); break; case 0x74: // -sg case 0x75: // -sl case 0x76: // -st case 0x77: // -sp var_type = (opcode >> 1) & 0x3; // Gets the variable type: g, l, t or p var_number = opparams[0]; r_temp = make_reg(0, -1 + validate_arithmetic(READ_VAR(var_type, var_number, s->r_acc))); PUSH32(r_temp); WRITE_VAR(var_type, var_number, r_temp); break; case 0x78: // -agi case 0x79: // -ali case 0x7a: // -ati case 0x7b: // -api var_type = (opcode >> 1) & 0x3; // Gets the variable type: g, l, t or p var_number = opparams[0] + signed_validate_arithmetic(s->r_acc); s->r_acc = make_reg(0, -1 + validate_arithmetic(READ_VAR(var_type, var_number, s->r_acc))); WRITE_VAR(var_type, var_number, s->r_acc); break; case 0x7c: // -sgi case 0x7d: // -sli case 0x7e: // -sti case 0x7f: // -spi var_type = (opcode >> 1) & 0x3; // Gets the variable type: g, l, t or p var_number = opparams[0] + signed_validate_arithmetic(s->r_acc); r_temp = make_reg(0, -1 + validate_arithmetic(READ_VAR(var_type, var_number, s->r_acc))); PUSH32(r_temp); WRITE_VAR(var_type, var_number, r_temp); break; default: script_error(s, __FILE__, __LINE__, "Illegal opcode"); } // switch(opcode >> 1) if (s->_executionStackPosChanged) // Force initialization xs = xs_new; //#ifndef DISABLE_VALIDATIONS if (xs != &(s->_executionStack.back())) { warning("xs is stale (%p vs %p); last command was %02x", (void *)xs, (void *)&(s->_executionStack.back()), opnumber); } //#endif #if 0 if (script_error_flag) { g_debug_step_running = 0; // Stop multiple execution g_debug_seeking = 0; // Stop special seeks xs->addr.pc.offset = old_pc_offset; xs->sp = old_sp; } else #endif ++script_step_counter; } } static int _obj_locate_varselector(EngineState *s, Object *obj, Selector slc) { // Determines if obj explicitly defines slc as a varselector // Returns -1 if not found if (s->_version < SCI_VERSION_1_1) { int varnum = obj->variable_names_nr; int selector_name_offset = varnum * 2 + SCRIPT_SELECTOR_OFFSET; int i; byte *buf = obj->base_obj + selector_name_offset; obj->base_vars = (uint16 *) buf; for (i = 0; i < varnum; i++) if (READ_LE_UINT16(buf + (i << 1)) == slc) // Found it? return i; // report success return -1; // Failed } else { byte *buf = (byte *) obj->base_vars; int i; int varnum = obj->_variables[1].offset; if (!(obj->_variables[SCRIPT_INFO_SELECTOR].offset & SCRIPT_INFO_CLASS)) buf = ((byte *) obj_get(s, obj->_variables[SCRIPT_SUPERCLASS_SELECTOR])->base_vars); for (i = 0; i < varnum; i++) if (READ_LE_UINT16(buf + (i << 1)) == slc) // Found it? return i; // report success return -1; // Failed } } static int _class_locate_funcselector(EngineState *s, Object *obj, Selector slc) { // Determines if obj is a class and explicitly defines slc as a funcselector // Does NOT say anything about obj's superclasses, i.e. failure may be // returned even if one of the superclasses defines the funcselector. int funcnum = obj->methods_nr; int i; for (i = 0; i < funcnum; i++) if (VM_OBJECT_GET_FUNCSELECTOR(obj, i) == slc) // Found it? return i; // report success return -1; // Failed } static SelectorType _lookup_selector_function(EngineState *s, int seg_id, Object *obj, Selector selector_id, reg_t *fptr) { int index; // "recursive" lookup while (obj) { index = _class_locate_funcselector(s, obj, selector_id); if (index >= 0) { if (fptr) { *fptr = VM_OBJECT_READ_FUNCTION(obj, index); } return kSelectorMethod; } else { seg_id = obj->_variables[SCRIPT_SUPERCLASS_SELECTOR].segment; obj = obj_get(s, obj->_variables[SCRIPT_SUPERCLASS_SELECTOR]); } } return kSelectorNone; } SelectorType lookup_selector(EngineState *s, reg_t obj_location, Selector selector_id, reg_t **vptr, reg_t *fptr) { Object *obj = obj_get(s, obj_location); Object *species; int index; // Early SCI versions used the LSB in the selector ID as a read/write // toggle, meaning that we must remove it for selector lookup. if (s->_flags & GF_SCI0_OLD) selector_id &= ~1; if (!obj) { CORE_ERROR("SLC-LU", "Attempt to send to non-object or invalid script"); sciprintf("Address was %04x:%04x\n", PRINT_REG(obj_location)); return kSelectorNone; } if (IS_CLASS(obj)) species = obj; else species = obj_get(s, obj->_variables[SCRIPT_SPECIES_SELECTOR]); if (!obj) { CORE_ERROR("SLC-LU", "Error while looking up Species class"); sciprintf("Original address was %04x:%04x\n", PRINT_REG(obj_location)); sciprintf("Species address was %04x:%04x\n", PRINT_REG(obj->_variables[SCRIPT_SPECIES_SELECTOR])); return kSelectorNone; } index = _obj_locate_varselector(s, obj, selector_id); if (index >= 0) { // Found it as a variable if (vptr) *vptr = &obj->_variables[index]; return kSelectorVariable; } return _lookup_selector_function(s, obj_location.segment, obj, selector_id, fptr); } SegmentId script_get_segment(EngineState *s, int script_nr, int load) { SegmentId segment; if ((load & SCRIPT_GET_LOAD) == SCRIPT_GET_LOAD) script_instantiate(s, script_nr); segment = s->seg_manager->segGet(script_nr); if (segment > 0) { if ((load & SCRIPT_GET_LOCK) == SCRIPT_GET_LOCK) s->seg_manager->getScript(segment)->incrementLockers(); return segment; } else return 0; } reg_t script_lookup_export(EngineState *s, int script_nr, int export_index) { SegmentId seg = script_get_segment(s, script_nr, SCRIPT_GET_DONT_LOAD); Script *script = NULL; #ifndef DISABLE_VALIDATIONS if (!seg) { CORE_ERROR("EXPORTS", "Script invalid or not loaded"); sciprintf("Script was script.%03d (0x%x)\n", script_nr, script_nr); return NULL_REG; } #endif script = script_locate_by_segment(s, seg); #ifndef DISABLE_VALIDATIONS if (script && export_index < script->exports_nr && export_index >= 0) #endif return make_reg(seg, READ_LE_UINT16((byte *)(script->export_table + export_index))); #ifndef DISABLE_VALIDATIONS else { CORE_ERROR("EXPORTS", "Export invalid or script missing "); if (!script) sciprintf("(script.%03d missing)\n", script_nr); else sciprintf("(script.%03d: Sought export %d/%d)\n", script_nr, export_index, script->exports_nr); return NULL_REG; } #endif } #define INST_LOOKUP_CLASS(id) ((id == 0xffff)? NULL_REG : get_class_address(s, id, SCRIPT_GET_LOCK, reg)) int script_instantiate_common(EngineState *s, int script_nr, Resource **script, Resource **heap, int *was_new) { int seg_id; reg_t reg; *was_new = 1; *script = s->resmgr->findResource(kResourceTypeScript, script_nr, 0); if (s->_version >= SCI_VERSION_1_1) *heap = s->resmgr->findResource(kResourceTypeHeap, script_nr, 0); if (!*script || (s->_version >= SCI_VERSION_1_1 && !heap)) { sciprintf("Script 0x%x requested but not found\n", script_nr); if (s->_version >= SCI_VERSION_1_1) { if (*heap) sciprintf("Inconsistency: heap resource WAS found\n"); else if (*script) sciprintf("Inconsistency: script resource WAS found\n"); } return 0; } if (NULL == s) { sciprintf("vm.c: script_instantiate(): NULL passed for \"s\"\n"); return 0; } seg_id = s->seg_manager->segGet(script_nr); Script *scr = script_locate_by_segment(s, seg_id); if (scr) { if (!scr->isMarkedAsDeleted()) { scr->incrementLockers(); return seg_id; } else { scr->freeScript(); } } else { scr = s->seg_manager->allocateScript(s, script_nr, &seg_id); if (!scr) { // ALL YOUR SCRIPT BASE ARE BELONG TO US error("Not enough heap space for script size 0x%x of script 0x%x (Should this happen?)", (*script)->size, script_nr); return 0; } } s->seg_manager->initialiseScript(*scr, s, script_nr); reg.segment = seg_id; reg.offset = 0; // Set heap position (beyond the size word) scr->setLockers(1); scr->setExportTableOffset(0); scr->setSynonymsOffset(0); scr->setSynonymsNr(0); *was_new = 0; return seg_id; } int script_instantiate_sci0(EngineState *s, int script_nr) { int objtype; unsigned int objlength; reg_t reg; int seg_id; int relocation = -1; int magic_pos_adder; // Usually 0; 2 for older SCI versions Resource *script; int was_new; seg_id = script_instantiate_common(s, script_nr, &script, NULL, &was_new); if (was_new) return seg_id; reg.segment = seg_id; reg.offset = 0; Script *scr = s->seg_manager->getScript(seg_id); if (s->_flags & GF_SCI0_OLD) { // int locals_nr = READ_LE_UINT16(script->data); // Old script block // There won't be a localvar block in this case // Instead, the script starts with a 16 bit int specifying the // number of locals we need; these are then allocated and zeroed. scr->mcpyInOut(0, script->data, script->size); magic_pos_adder = 2; // Step over the funny prefix if (locals_nr) s->seg_manager->scriptInitialiseLocalsZero(reg.segment, locals_nr); } else { scr->mcpyInOut(0, script->data, script->size); magic_pos_adder = 0; } // Now do a first pass through the script objects to find the // export table and local variable block objlength = 0; reg.offset = magic_pos_adder; do { reg_t data_base; reg_t addr; reg.offset += objlength; // Step over the last checked object objtype = scr->getHeap(reg.offset); if (!objtype) break; objlength = scr->getHeap(reg.offset + 2); data_base = reg; data_base.offset += 4; addr = data_base; switch (objtype) { case SCI_OBJ_EXPORTS: { scr->setExportTableOffset(data_base.offset); } break; case SCI_OBJ_SYNONYMS: scr->setSynonymsOffset(addr.offset); // +4 is to step over the header scr->setSynonymsNr((objlength) / 4); break; case SCI_OBJ_LOCALVARS: s->seg_manager->scriptInitialiseLocals(data_base); break; case SCI_OBJ_CLASS: { int classpos = addr.offset - SCRIPT_OBJECT_MAGIC_OFFSET; int species; species = scr->getHeap(addr.offset - SCRIPT_OBJECT_MAGIC_OFFSET + SCRIPT_SPECIES_OFFSET); if (species < 0 || species >= (int)s->_classtable.size()) { error("Invalid species %d(0x%x) not in interval " "[0,%d) while instantiating script %d\n", species, species, s->_classtable.size(), script_nr); return 1; } s->_classtable[species].script = script_nr; s->_classtable[species].reg = addr; s->_classtable[species].reg.offset = classpos; // Set technical class position-- into the block allocated for it } break; default: break; } } while (objtype != 0); // And now a second pass to adjust objects and class pointers, and the general pointers objlength = 0; reg.offset = magic_pos_adder; // Reset counter do { reg_t addr; reg.offset += objlength; // Step over the last checked object objtype = scr->getHeap(reg.offset); if (!objtype) break; objlength = scr->getHeap(reg.offset + 2); reg.offset += 4; // Step over header addr = reg; switch (objtype) { case SCI_OBJ_CODE: s->seg_manager->scriptAddCodeBlock(addr); break; case SCI_OBJ_OBJECT: case SCI_OBJ_CLASS: { // object or class? Object *obj = s->seg_manager->scriptObjInit(s, addr); Object *base_obj; // Instantiate the superclass, if neccessary obj->_variables[SCRIPT_SPECIES_SELECTOR] = INST_LOOKUP_CLASS(obj->_variables[SCRIPT_SPECIES_SELECTOR].offset); base_obj = obj_get(s, obj->_variables[SCRIPT_SPECIES_SELECTOR]); obj->variable_names_nr = base_obj->_variables.size(); obj->base_obj = base_obj->base_obj; // Copy base from species class, as we need its selector IDs obj->_variables[SCRIPT_SUPERCLASS_SELECTOR] = INST_LOOKUP_CLASS(obj->_variables[SCRIPT_SUPERCLASS_SELECTOR].offset); } // if object or class break; case SCI_OBJ_POINTERS: // A relocation table relocation = addr.offset; break; default: break; } reg.offset -= 4; // Step back on header } while ((objtype != 0) && (((unsigned)reg.offset) < script->size - 2)); if (relocation >= 0) s->seg_manager->scriptRelocate(make_reg(reg.segment, relocation)); return reg.segment; // instantiation successful } int script_instantiate_sci11(EngineState *s, int script_nr) { Resource *script, *heap; int seg_id; int heap_start; reg_t reg; int was_new; seg_id = script_instantiate_common(s, script_nr, &script, &heap, &was_new); if (was_new) return seg_id; Script *scr = s->seg_manager->getScript(seg_id); heap_start = script->size; if (script->size & 2) heap_start ++; scr->mcpyInOut(0, script->data, script->size); scr->mcpyInOut(heap_start, heap->data, heap->size); if (READ_LE_UINT16(script->data + 6) > 0) scr->setExportTableOffset(6); reg.segment = seg_id; reg.offset = heap_start + 4; s->seg_manager->scriptInitialiseLocals(reg); s->seg_manager->scriptRelocateExportsSci11(seg_id); s->seg_manager->scriptInitialiseObjectsSci11(s, seg_id); reg.offset = READ_LE_UINT16(heap->data); s->seg_manager->heapRelocate(reg); return seg_id; } int script_instantiate(EngineState *s, int script_nr) { if (s->_version >= SCI_VERSION_1_1) return script_instantiate_sci11(s, script_nr); else return script_instantiate_sci0(s, script_nr); } void script_uninstantiate_sci0(EngineState *s, int script_nr, SegmentId seg) { reg_t reg = make_reg(seg, (s->_flags & GF_SCI0_OLD) ? 2 : 0); int objtype, objlength; Script *scr = s->seg_manager->getScript(seg); // Make a pass over the object in order uninstantiate all superclasses objlength = 0; do { reg.offset += objlength; // Step over the last checked object objtype = scr->getHeap(reg.offset); if (!objtype) break; objlength = scr->getHeap(reg.offset + 2); // use SEG_UGET_HEAP ?? reg.offset += 4; // Step over header if ((objtype == SCI_OBJ_OBJECT) || (objtype == SCI_OBJ_CLASS)) { // object or class? int superclass; reg.offset -= SCRIPT_OBJECT_MAGIC_OFFSET; superclass = scr->getHeap(reg.offset + SCRIPT_SUPERCLASS_OFFSET); // Get superclass... if (superclass >= 0) { int superclass_script = s->_classtable[superclass].script; if (superclass_script == script_nr) { if (scr->getLockers()) scr->decrementLockers(); // Decrease lockers if this is us ourselves } else script_uninstantiate(s, superclass_script); // Recurse to assure that the superclass lockers number gets decreased } reg.offset += SCRIPT_OBJECT_MAGIC_OFFSET; } // if object or class reg.offset -= 4; // Step back on header } while (objtype != 0); } void script_uninstantiate(EngineState *s, int script_nr) { reg_t reg = make_reg(0, (s->_flags & GF_SCI0_OLD) ? 2 : 0); reg.segment = s->seg_manager->segGet(script_nr); Script *scr = script_locate_by_segment(s, reg.segment); if (!scr) { // Is it already loaded? //warning("unloading script 0x%x requested although not loaded", script_nr); // This is perfectly valid SCI behaviour return; } scr->decrementLockers(); // One less locker if (scr->getLockers() > 0) return; // Free all classtable references to this script for (uint i = 0; i < s->_classtable.size(); i++) if (s->_classtable[i].reg.segment == reg.segment) s->_classtable[i].reg = NULL_REG; if (s->_version < SCI_VERSION_1_1) script_uninstantiate_sci0(s, script_nr, reg.segment); else sciprintf("FIXME: Add proper script uninstantiation for SCI 1.1\n"); if (scr->getLockers()) return; // if xxx.lockers > 0 // Otherwise unload it completely // Explanation: I'm starting to believe that this work is done by SCI itself. scr->markDeleted(); debugC(kDebugLevelScripts, "Unloaded script 0x%x.\n", script_nr); return; } static void _init_stack_base_with_selector(EngineState *s, Selector selector) { s->stack_base[0] = make_reg(0, (uint16)selector); s->stack_base[1] = NULL_REG; } EngineState *g_EngineState = 0; static EngineState *_game_run(EngineState *s, int restoring) { EngineState *successor = NULL; int game_is_finished = 0; g_EngineState = s; do { s->_executionStackPosChanged = false; run_vm(s, (successor || restoring) ? 1 : 0); if (s->restarting_flags & SCI_GAME_IS_RESTARTING_NOW) { // Restart was requested? successor = NULL; s->_executionStack.clear(); s->_executionStackPosChanged = false; game_exit(s); script_free_engine(s); script_init_engine(s); game_init(s); sfx_reset_player(); _init_stack_base_with_selector(s, s->_kernel->_selectorMap.play); send_selector(s, s->game_obj, s->game_obj, s->stack_base, 2, s->stack_base); script_abort_flag = 0; s->restarting_flags = SCI_GAME_WAS_RESTARTED | SCI_GAME_WAS_RESTARTED_AT_LEAST_ONCE; } else { successor = s->successor; if (successor) { game_exit(s); script_free_vm_memory(s); delete s; s = successor; g_EngineState = s; if (script_abort_flag == SCRIPT_ABORT_WITH_REPLAY) { sciprintf("Restarting with replay()\n"); s->_executionStack.clear(); // Restart with replay _init_stack_base_with_selector(s, s->_kernel->_selectorMap.replay); send_selector(s, s->game_obj, s->game_obj, s->stack_base, 2, s->stack_base); } script_abort_flag = 0; } else game_is_finished = 1; } } while (!game_is_finished); return s; } int printObject(EngineState *s, reg_t pos); int game_run(EngineState **_s) { EngineState *s = *_s; sciprintf(" Calling %s::play()\n", s->_gameName.c_str()); _init_stack_base_with_selector(s, s->_kernel->_selectorMap.play); // Call the play selector // Now: Register the first element on the execution stack- if (!send_selector(s, s->game_obj, s->game_obj, s->stack_base, 2, s->stack_base)) { printObject(s, s->game_obj); sciprintf("Failed to run the game! Aborting...\n"); return 1; } // and ENGAGE! *_s = s = _game_run(s, 0); sciprintf(" Game::play() finished.\n"); return 0; } Object *obj_get(EngineState *s, reg_t offset) { MemObject *mobj = GET_OBJECT_SEGMENT(*s->seg_manager, offset.segment); Object *obj = NULL; int idx; if (mobj != NULL) { if (mobj->getType() == MEM_OBJ_CLONES) { CloneTable *ct = (CloneTable *)mobj; if (ct->isValidEntry(offset.offset)) obj = &(ct->_table[offset.offset]); } else if (mobj->getType() == MEM_OBJ_SCRIPT) { Script *scr = (Script *)mobj; if (offset.offset <= scr->buf_size && offset.offset >= -SCRIPT_OBJECT_MAGIC_OFFSET && RAW_IS_OBJECT(scr->buf + offset.offset)) { idx = RAW_GET_CLASS_INDEX(scr, offset); if (idx >= 0 && (uint)idx < scr->_objects.size()) obj = &scr->_objects[idx]; } } } return obj; } const char *obj_get_name(EngineState *s, reg_t pos) { Object *obj = obj_get(s, pos); if (!obj) return ""; reg_t nameReg = obj->_variables[SCRIPT_NAME_SELECTOR]; if (nameReg.isNull()) return ""; const char *name = (const char*)s->seg_manager->dereference(obj->_variables[SCRIPT_NAME_SELECTOR], NULL); if (!name) return ""; return name; } void quit_vm() { script_abort_flag = 1; // Terminate VM g_debugstate_valid = 0; g_debug_seeking = 0; g_debug_step_running = 0; } void shrink_execution_stack(EngineState *s, uint size) { assert(s->_executionStack.size() >= size); Common::List::iterator iter; iter = s->_executionStack.begin(); for (uint i = 0; i < size; ++i) ++iter; s->_executionStack.erase(iter, s->_executionStack.end()); } } // End of namespace Sci