/* Copyright (C) 2003-2013 Runtime Revolution Ltd.

This file is part of LiveCode.

LiveCode is free software; you can redistribute it and/or modify it under

the terms of the GNU General Public License v3 as published by the Free

Software Foundation.

LiveCode 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 LiveCode. If not see <http://www.gnu.org/licenses/>. */

#include "libscript/script.h"

#include "script-private.h"

#include "ffi.h"

#include "foundation-auto.h"

#ifdef _WIN32

#include <windows.h>

#else

#include <dlfcn.h>

#endif

////////////////////////////////////////////////////////////////////////////////

// This context struct, callbacks and associated functions provide an implementation

// of MCHandler for handlers coming from libscript. It enables an MCHandlerRef

// created from within LCB to be used 'out-of-frame' - i.e. not just from direct

// invocation within the LCB VM.

struct __MCScriptHandlerContext

{

MCScriptInstanceRef instance;

MCScriptCommonHandlerDefinition *definition;

};

extern MCHandlerCallbacks __kMCScriptHandlerCallbacks;

bool __MCScriptHandlerInvoke(void *context, MCValueRef *p_arguments, uindex_t p_argument_count, MCValueRef& r_value);

void __MCScriptHandlerRelease(void *context);

bool __MCScriptHandlerDescribe(void *context, MCStringRef &r_desc);

////////////////////////////////////////////////////////////////////////////////

// This is the module of the most recent LCB stack frame on the current thread's

// stack. It is set before and after a foreign handler call so that the native

// code can get some element of context.

static MCScriptModuleRef s_current_module = nil;

////////////////////////////////////////////////////////////////////////////////

bool MCScriptCreateInstanceOfModule(MCScriptModuleRef p_module, MCScriptInstanceRef& r_instance)

{

bool t_success;

t_success = true;

MCScriptInstanceRef t_instance;

t_instance = nil;

// If the module is not usable, then we cannot create an instance.

if (t_success)

if (!p_module -> is_usable)

return false;

// If this is a module which shares a single instance, then return that if we have

// one.

if (p_module -> module_kind != kMCScriptModuleKindWidget &&

p_module -> shared_instance != nil)

{

r_instance = MCScriptRetainInstance(p_module -> shared_instance);

return true;

}

// Attempt to create a script object.

if (t_success)

t_success = MCScriptCreateObject(kMCScriptObjectKindInstance, sizeof(MCScriptInstance), (MCScriptObject*&)t_instance);

// Now associate the script object with the module (so the 'slots' field make sense).

if (t_success)

{

t_instance -> module = MCScriptRetainModule(p_module);

}

// Now allocate the slots field.

if (t_success)

t_success = MCMemoryNewArray(p_module -> slot_count, t_instance -> slots);

if (t_success)

{

for(uindex_t i = 0; i < p_module -> slot_count; i++)

t_instance -> slots[i] = MCValueRetain(kMCNull);

// If this is a module which shares its instance, then add a link to it.

// (Note this is weak reference - we don't retain, otherwise we would have

// a cycle!).

if (p_module -> module_kind != kMCScriptModuleKindWidget)

p_module -> shared_instance = t_instance;

r_instance = t_instance;

}

else

MCScriptDestroyObject(t_instance);

return t_success;

}

void MCScriptDestroyInstance(MCScriptInstanceRef self)

{

__MCScriptValidateObjectAndKind__(self, kMCScriptObjectKindInstance);

// If the object had slots initialized, then free them.

if (self -> slots != nil)

{

for(uindex_t i = 0; i < self -> module -> slot_count; i++)

MCValueRelease(self -> slots[i]);

MCMemoryDeleteArray(self -> slots);

}

// If the instance has a module, and this is the shared instance then set

// the shared instance field to nil.

if (self -> module != nil &&

self -> module -> shared_instance == self)

self -> module -> shared_instance = nil;

// If the instance was associated with its module, then release it.

if (self -> module != nil)

MCScriptReleaseModule(self -> module);

// The rest of the deallocation is handled by MCScriptDestroyObject.

}

////////////////////////////////////////////////////////////////////////////////

MCScriptInstanceRef MCScriptRetainInstance(MCScriptInstanceRef self)

{

__MCScriptValidateObjectAndKind__(self, kMCScriptObjectKindInstance);

return (MCScriptInstanceRef)MCScriptRetainObject(self);

}

void MCScriptReleaseInstance(MCScriptInstanceRef self)

{

if (nil == self)

return;

__MCScriptValidateObjectAndKind__(self, kMCScriptObjectKindInstance);

MCScriptReleaseObject(self);

}

////////////////////////////////////////////////////////////////////////////////

MCScriptModuleRef MCScriptGetModuleOfInstance(MCScriptInstanceRef self)

{

return self -> module;

}

////////////////////////////////////////////////////////////////////////////////

bool MCHandlerTypeInfoConformsToPropertyGetter(MCTypeInfoRef typeinfo)

{

return MCHandlerTypeInfoGetParameterCount(typeinfo) == 0 &&

MCHandlerTypeInfoGetReturnType(typeinfo) != kMCNullTypeInfo;

}

bool MCHandlerTypeInfoConformsToPropertySetter(MCTypeInfoRef typeinfo)

{

return MCHandlerTypeInfoGetParameterCount(typeinfo) == 1 &&

MCHandlerTypeInfoGetParameterMode(typeinfo, 0) == kMCHandlerTypeFieldModeIn;

}

///////////

bool MCScriptThrowAttemptToSetReadOnlyPropertyError(MCScriptModuleRef p_module, MCNameRef p_property)

{

return MCErrorCreateAndThrow(kMCScriptCannotSetReadOnlyPropertyErrorTypeInfo, "module", p_module -> name, "property", p_property, nil);

}

bool MCScriptThrowInvalidValueForPropertyError(MCScriptModuleRef p_module, MCNameRef p_property, MCTypeInfoRef p_expected_type, MCValueRef p_value)

{

return MCErrorCreateAndThrow(kMCScriptInvalidPropertyValueErrorTypeInfo, "module", p_module -> name, "property", p_property, "type", MCNamedTypeInfoGetName(p_expected_type), "value", p_value, nil);

}

bool MCScriptThrowInvalidValueForResultError(MCScriptModuleRef p_module, MCScriptDefinition *p_handler, MCTypeInfoRef p_expected_type, MCValueRef p_value)

{

return MCErrorCreateAndThrow(kMCScriptInvalidReturnValueErrorTypeInfo, "module", p_module -> name, "handler", MCScriptGetNameOfDefinitionInModule(p_module, p_handler), "type", MCNamedTypeInfoGetName(p_expected_type), "value", p_value, nil);

}

bool MCScriptThrowInParameterNotDefinedError(MCScriptModuleRef p_module, MCScriptDefinition *p_handler, uindex_t p_index)

{

return MCErrorCreateAndThrow(kMCScriptInParameterNotDefinedErrorTypeInfo, "module", p_module -> name, "handler", MCScriptGetNameOfDefinitionInModule(p_module, p_handler), "parameter", MCScriptGetNameOfParameterInModule(p_module, p_handler, p_index), nil);

}

bool MCScriptThrowOutParameterNotDefinedError(MCScriptModuleRef p_module, MCScriptDefinition *p_handler, uindex_t p_index)

{

return MCErrorCreateAndThrow(kMCScriptOutParameterNotDefinedErrorTypeInfo, "module", p_module -> name, "handler", MCScriptGetNameOfDefinitionInModule(p_module, p_handler), "parameter", MCScriptGetNameOfParameterInModule(p_module, p_handler, p_index), nil);

}

bool MCScriptThrowLocalVariableUsedBeforeDefinedError(MCScriptModuleRef p_module, MCScriptDefinition *p_handler, uindex_t p_index)

{

return MCErrorCreateAndThrow(kMCScriptVariableUsedBeforeDefinedErrorTypeInfo, "module", p_module -> name, "handler", MCScriptGetNameOfDefinitionInModule(p_module, p_handler), "variable", MCScriptGetNameOfLocalVariableInModule(p_module, p_handler, p_index), nil);

}

bool MCScriptThrowGlobalVariableUsedBeforeDefinedError(MCScriptModuleRef p_module, uindex_t p_index)

{

return MCErrorCreateAndThrow(kMCScriptVariableUsedBeforeDefinedErrorTypeInfo, "module", p_module -> name, "variable", MCScriptGetNameOfGlobalVariableInModule(p_module, p_index), nil);

}

bool MCScriptThrowInvalidValueForLocalVariableError(MCScriptModuleRef p_module, MCScriptDefinition *p_handler, uindex_t p_index, MCTypeInfoRef p_expected_type, MCValueRef p_value)

{

return MCErrorCreateAndThrow(kMCScriptInvalidVariableValueErrorTypeInfo, "module", p_module -> name, "handler", MCScriptGetNameOfDefinitionInModule(p_module, p_handler), "variable", MCScriptGetNameOfLocalVariableInModule(p_module, p_handler, p_index), "type", MCNamedTypeInfoGetName(p_expected_type), "value", p_value, nil);

}

bool MCScriptThrowInvalidValueForGlobalVariableError(MCScriptModuleRef p_module, uindex_t p_index, MCTypeInfoRef p_expected_type, MCValueRef p_value)

{

return MCErrorCreateAndThrow(kMCScriptInvalidVariableValueErrorTypeInfo, "module", p_module -> name, "variable", MCScriptGetNameOfGlobalVariableInModule(p_module, p_index), "type", MCNamedTypeInfoGetName(p_expected_type), "value", p_value, nil);

}

bool MCScriptThrowInvalidValueForContextVariableError(MCScriptModuleRef p_module, uindex_t p_index, MCTypeInfoRef p_expected_type, MCValueRef p_value)

{

return MCErrorCreateAndThrow(kMCScriptInvalidVariableValueErrorTypeInfo, "module", p_module -> name, "variable", MCScriptGetNameOfContextVariableInModule(p_module, p_index), "type", MCNamedTypeInfoGetName(p_expected_type), "value", p_value, nil);

}

bool MCScriptThrowNotABooleanError(MCValueRef p_value)

{

return MCErrorCreateAndThrow(kMCScriptNotABooleanValueErrorTypeInfo, "value", p_value, nil);

}

bool MCScriptThrowWrongNumberOfArgumentsForInvokeError(MCScriptModuleRef p_module, MCScriptDefinition *p_definition, uindex_t p_provided)

{

// TODO: Encode provided / expected.

return MCErrorCreateAndThrow(kMCScriptWrongNumberOfArgumentsErrorTypeInfo, "module", p_module -> name, "handler", MCScriptGetNameOfDefinitionInModule(p_module, p_definition), nil);

}

bool MCScriptThrowInvalidValueForArgumentError(MCScriptModuleRef p_module, MCScriptDefinition *p_definition, uindex_t p_arg_index, MCTypeInfoRef p_expected_type, MCValueRef p_value)

{

return MCErrorCreateAndThrow(kMCScriptInvalidArgumentValueErrorTypeInfo, "module", p_module -> name, "handler", MCScriptGetNameOfDefinitionInModule(p_module, p_definition), "parameter", MCScriptGetNameOfParameterInModule(p_module, p_definition, p_arg_index), "type", MCNamedTypeInfoGetName(p_expected_type), "value", p_value, nil);

}

bool MCScriptThrowUnableToResolveForeignHandlerError(MCScriptModuleRef p_module, MCScriptDefinition *p_definition)

{

return MCErrorCreateAndThrow(kMCScriptForeignHandlerBindingErrorTypeInfo, "module", p_module -> name, "handler", MCScriptGetNameOfDefinitionInModule(p_module, p_definition), nil);

}

bool MCScriptThrowUnableToResolveTypeError(MCTypeInfoRef p_type)

{

return MCErrorCreateAndThrow(kMCScriptTypeBindingErrorTypeInfo, "type", MCNamedTypeInfoGetName(p_type), nil);

}

bool MCScriptThrowUnableToResolveMultiInvoke(MCScriptModuleRef p_module, MCScriptDefinition *p_definition, MCProperListRef p_arguments)

{

MCAutoListRef t_handlers;

if (!MCListCreateMutable(',', &t_handlers))

return false;

MCScriptDefinitionGroupDefinition *t_group;

t_group = static_cast<MCScriptDefinitionGroupDefinition *>(p_definition);

for(uindex_t i = 0; i < t_group -> handler_count; i++)

{

MCNameRef t_name;

t_name = MCScriptGetNameOfDefinitionInModule(p_module, p_module -> definitions[t_group -> handlers[i]]);

if (!MCListAppend(*t_handlers, t_name))

return false;

}

MCAutoListRef t_types;

if (!MCListCreateMutable(',', &t_types))

return false;

for(uindex_t i = 0; i < MCProperListGetLength(p_arguments); i++)

if (!MCListAppend(*t_types, MCNamedTypeInfoGetName(MCValueGetTypeInfo(MCProperListFetchElementAtIndex(p_arguments, i)))))

return false;

MCAutoStringRef t_handler_list, t_type_list;

if (!MCListCopyAsString(*t_handlers, &t_handler_list) ||

!MCListCopyAsString(*t_types, &t_type_list))

return false;

return MCErrorCreateAndThrow(kMCScriptNoMatchingHandlerErrorTypeInfo, "handlers", *t_handler_list, "types", *t_type_list, nil);

}

bool MCScriptThrowNotAHandlerValueError(MCValueRef p_value)

{

return MCErrorCreateAndThrow(kMCScriptNotAHandlerValueErrorTypeInfo, "value", p_value, nil);

}

bool MCScriptThrowCannotCallContextHandlerError(MCScriptModuleRef p_module, MCScriptDefinition *p_handler)

{

return MCErrorCreateAndThrow(kMCScriptCannotCallContextHandlerErrorTypeInfo, "module", p_module -> name, "handler", MCScriptGetNameOfDefinitionInModule(p_module, p_handler), nil);

}

bool MCScriptThrowHandlerNotFoundError(MCScriptModuleRef p_module, MCNameRef p_handler)

{

return MCErrorCreateAndThrow(kMCScriptHandlerNotFoundErrorTypeInfo, "module", p_module -> name, "handler", p_handler, nil);

}

bool MCScriptThrowPropertyNotFoundError(MCScriptModuleRef p_module, MCNameRef p_property)

{

return MCErrorCreateAndThrow(kMCScriptPropertyNotFoundErrorTypeInfo, "module", p_module -> name, "property", p_property, nil);

}

///////////

MCScriptVariableDefinition *MCScriptDefinitionAsVariable(MCScriptDefinition *self)

{

__MCScriptAssert__(self -> kind == kMCScriptDefinitionKindVariable,

"definition not a variable");

return static_cast<MCScriptVariableDefinition *>(self);

}

MCScriptHandlerDefinition *MCScriptDefinitionAsHandler(MCScriptDefinition *self)

{

__MCScriptAssert__(self -> kind == kMCScriptDefinitionKindHandler,

"definition not a handler");

return static_cast<MCScriptHandlerDefinition *>(self);

}

MCScriptForeignHandlerDefinition *MCScriptDefinitionAsForeignHandler(MCScriptDefinition *self)

{

__MCScriptAssert__(self -> kind == kMCScriptDefinitionKindForeignHandler,

"definition not a foreign handler");

return static_cast<MCScriptForeignHandlerDefinition *>(self);

}

MCScriptDefinitionGroupDefinition *MCScriptDefinitionAsDefinitionGroup(MCScriptDefinition *self)

{

__MCScriptAssert__(self -> kind == kMCScriptDefinitionKindDefinitionGroup,

"definition not a definition group");

return static_cast<MCScriptDefinitionGroupDefinition *>(self);

}

///////////

bool MCScriptGetPropertyOfInstance(MCScriptInstanceRef self, MCNameRef p_property, MCValueRef& r_value)

{

__MCScriptValidateObjectAndKind__(self, kMCScriptObjectKindInstance);

// Lookup the definition (throws if not found).

MCScriptPropertyDefinition *t_definition;

if (!MCScriptLookupPropertyDefinitionInModule(self -> module, p_property, t_definition))

return MCScriptThrowPropertyNotFoundError(self -> module, p_property);

MCScriptDefinition *t_getter;

t_getter = t_definition -> getter != 0 ? self -> module -> definitions[t_definition -> getter - 1] : nil;

/* LOAD CHECK */ __MCScriptAssert__(t_getter != nil,

"property has no getter");

/* LOAD CHECK */ __MCScriptAssert__(t_getter -> kind == kMCScriptDefinitionKindVariable ||

t_getter -> kind == kMCScriptDefinitionKindHandler,

"property getter is not a variable or handler");

if (t_getter -> kind == kMCScriptDefinitionKindVariable)

{

// The easy case - fetching a variable-based property.

MCScriptVariableDefinition *t_variable_def;

t_variable_def = MCScriptDefinitionAsVariable(t_getter);

// Variables are backed by an slot in the instance.

uindex_t t_slot_index;

t_slot_index = t_variable_def -> slot_index;

/* COMPUTE CHECK */ __MCScriptAssert__(t_slot_index < self -> module -> slot_count,

"computed variable slot out of range");

// Slot based properties are easy, we just copy the value out of the slot.

r_value = MCValueRetain(self -> slots[t_slot_index]);

}

else if (t_getter -> kind == kMCScriptDefinitionKindHandler)

{

// The more difficult case - we have to execute a handler.

MCScriptHandlerDefinition *t_handler_def;

t_handler_def = MCScriptDefinitionAsHandler(t_getter);

/* LOAD CHECK */ __MCScriptAssert__(MCHandlerTypeInfoConformsToPropertyGetter(self -> module -> types[t_handler_def -> type] -> typeinfo),

"incorrect signature for property getter");

if (!MCScriptCallHandlerOfInstanceInternal(self, t_handler_def, nil, 0, r_value))

return false;

}

else

{

__MCScriptUnreachable__("inconsistency with definition kind in property fetching");

}

return true;

}

bool MCScriptSetPropertyOfInstance(MCScriptInstanceRef self, MCNameRef p_property, MCValueRef p_value)

{

__MCScriptValidateObjectAndKind__(self, kMCScriptObjectKindInstance);

// Lookup the definition.

MCScriptPropertyDefinition *t_definition;

if (!MCScriptLookupPropertyDefinitionInModule(self -> module, p_property, t_definition))

return MCScriptThrowPropertyNotFoundError(self -> module, p_property);

MCScriptDefinition *t_setter;

t_setter = t_definition -> setter != 0 ? self -> module -> definitions[t_definition -> setter - 1] : nil;

// If there is no setter for the property then this is an error.

if (t_setter == nil)

return MCScriptThrowAttemptToSetReadOnlyPropertyError(self -> module, p_property);

/* LOAD CHECK */ __MCScriptAssert__(t_setter != nil,

"property has no setter");

/* LOAD CHECK */ __MCScriptAssert__(t_setter -> kind == kMCScriptDefinitionKindVariable ||

t_setter -> kind == kMCScriptDefinitionKindHandler,

"property setter is not a variable or handler");

if (t_setter -> kind == kMCScriptDefinitionKindVariable)

{

// The easy case - storing a variable-based property.

MCScriptVariableDefinition *t_variable_def;

t_variable_def = MCScriptDefinitionAsVariable(t_setter);

MCTypeInfoRef t_type;

t_type = self -> module -> types[t_variable_def -> type] -> typeinfo;

// Make sure the value is of the correct type - if not it is an error.

// (The caller has to ensure things are converted as appropriate).

if (!MCTypeInfoConforms(MCValueGetTypeInfo(p_value), t_type))

return MCScriptThrowInvalidValueForPropertyError(self -> module, p_property, t_type, p_value);

// Variables are backed by an slot in the instance.

uindex_t t_slot_index;

t_slot_index = t_variable_def -> slot_index;

/* COMPUTE CHECK */ __MCScriptAssert__(t_slot_index < self -> module -> slot_count,

"computed variable slot out of range");

// If the value of the slot isn't changing, assign our new value.

if (p_value != self -> slots[t_slot_index])

{

MCValueRelease(self -> slots[t_slot_index]);

self -> slots[t_slot_index] = MCValueRetain(p_value);

}

}

else if (t_setter -> kind == kMCScriptDefinitionKindHandler)

{

// The more difficult case - we have to execute a handler.

MCScriptHandlerDefinition *t_handler_def;

t_handler_def = MCScriptDefinitionAsHandler(t_setter);

/* LOAD CHECK */ __MCScriptAssert__(MCHandlerTypeInfoConformsToPropertySetter(self -> module -> types[t_handler_def -> type] -> typeinfo),

"incorrect signature for property setter");

// Get the required type of the parameter.

MCTypeInfoRef t_property_type;

t_property_type = MCHandlerTypeInfoGetParameterType(self -> module -> types[t_handler_def -> type] -> typeinfo, 0);

// Make sure the value if of the correct type - if not it is an error.

// (The caller has to ensure things are converted as appropriate).

if (!MCTypeInfoConforms(MCValueGetTypeInfo(p_value), t_property_type))

return MCScriptThrowInvalidValueForPropertyError(self -> module, p_property, t_property_type, p_value);

MCValueRef t_result;

if (!MCScriptCallHandlerOfInstanceInternal(self, t_handler_def, &p_value, 1, t_result))

return false;

MCValueRelease(t_result);

}

else

{

__MCScriptUnreachable__("inconsistency with definition kind in property fetching");

}

return true;

}

static bool MCScriptCallHandlerOfInstanceDirect(MCScriptInstanceRef self, MCScriptHandlerDefinition *p_handler, MCValueRef *p_arguments, uindex_t p_argument_count, MCValueRef& r_value)

{

// Get the signature of the handler.

MCTypeInfoRef t_signature;

t_signature = self -> module -> types[p_handler -> type] -> typeinfo;

// If the handler is of context scope, then we cannot call it directly - only

// from a LCB frame.

if (p_handler -> scope == kMCScriptHandlerScopeContext)

return MCScriptThrowCannotCallContextHandlerError(self -> module, p_handler);

// Check the number of arguments.

uindex_t t_required_param_count;

t_required_param_count = MCHandlerTypeInfoGetParameterCount(t_signature);

if (t_required_param_count != p_argument_count)

return MCScriptThrowWrongNumberOfArgumentsForInvokeError(self -> module, p_handler, p_argument_count);

// Check the types of the arguments.

for(uindex_t i = 0; i < t_required_param_count; i++)

{

MCHandlerTypeFieldMode t_mode;

t_mode = MCHandlerTypeInfoGetParameterMode(t_signature, i);

if (t_mode != kMCHandlerTypeFieldModeOut)

{

if (p_arguments[i] == nil)

return MCScriptThrowInParameterNotDefinedError(self -> module, p_handler, i);

MCTypeInfoRef t_type;

t_type = MCHandlerTypeInfoGetParameterType(t_signature, i);

if (!MCTypeInfoConforms(MCValueGetTypeInfo(p_arguments[i]), t_type))

return MCScriptThrowInvalidValueForArgumentError(self -> module, p_handler, i, t_type, p_arguments[i]);

}

}

// Now the input argument array is appropriate, we can just call the handler.

if (!MCScriptCallHandlerOfInstanceInternal(self, p_handler, p_arguments, p_argument_count, r_value))

return false;

return true;

}

bool MCScriptCallHandlerOfInstance(MCScriptInstanceRef self, MCNameRef p_handler, MCValueRef *p_arguments, uindex_t p_argument_count, MCValueRef& r_value)

{

__MCScriptValidateObjectAndKind__(self, kMCScriptObjectKindInstance);

// Lookup the definition (throws if not found).

MCScriptHandlerDefinition *t_definition;

if (!MCScriptLookupHandlerDefinitionInModule(self -> module, p_handler, t_definition))

return MCScriptThrowHandlerNotFoundError(self -> module, p_handler);

return MCScriptCallHandlerOfInstanceDirect(self, t_definition, p_arguments, p_argument_count, r_value);

}

bool MCScriptCallHandlerOfInstanceIfFound(MCScriptInstanceRef self, MCNameRef p_handler, MCValueRef *p_arguments, uindex_t p_argument_count, MCValueRef& r_value)

{

__MCScriptValidateObjectAndKind__(self, kMCScriptObjectKindInstance);

// Lookup the definition (throws if not found).

MCScriptHandlerDefinition *t_definition;

if (!MCScriptLookupHandlerDefinitionInModule(self -> module, p_handler, t_definition))

{

r_value = MCValueRetain(kMCNull);

return true;

}

return MCScriptCallHandlerOfInstanceDirect(self, t_definition, p_arguments, p_argument_count, r_value);

}

////////////////////////////////////////////////////////////////////////////////

struct MCScriptFrameContext

{

uindex_t count;

MCValueRef slots[1];

};

// This structure is a single frame on the execution stack.

struct MCScriptFrame

{

// The calling frame.

MCScriptFrame *caller;

// The instance we are executing within.

MCScriptInstanceRef instance;

// The handler of the instance's module being run right now.

MCScriptHandlerDefinition *handler;

// The address (instruction pointer) into the instance's module bytecode.

uindex_t address;

// The slots for the current handler invocation. The slots are in this order:

// <parameters>

// <locals>

// <registers>

MCValueRef *slots;

// The context slots for the current handler invocation (if initialized)

MCScriptFrameContext *context;

// The result register in the caller.

uindex_t result;

// The mapping array - this lists the mapping from parameters to registers

// in the callers frame, for handling inout/out parameters.

uindex_t *mapping;

};

static inline bool MCScriptIsRegisterValidInFrame(MCScriptFrame *p_frame, int p_register)

{

return p_register >= 0 && p_register < p_frame -> handler -> slot_count;

}

static inline bool MCScriptIsConstantValidInFrame(MCScriptFrame *p_frame, int p_constant)

{

return p_constant >= 0 && p_constant < p_frame -> instance -> module -> value_count;

}

static bool MCScriptCreateFrame(MCScriptFrame *p_caller, MCScriptInstanceRef p_instance, MCScriptHandlerDefinition *p_handler, MCScriptFrame*& r_frame)

{

MCScriptFrame *self;

self = nil;

if (!MCMemoryNew(self) ||

!MCMemoryNewArray(p_handler -> slot_count, self -> slots))

{

MCMemoryDelete(self);

return false;

}

for(uindex_t i = 0; i < p_handler -> slot_count; i++)

self -> slots[i] = MCValueRetain(kMCNull);

self -> caller = p_caller;

self -> instance = MCScriptRetainInstance(p_instance);

self -> handler = p_handler;

self -> address = p_handler -> start_address;

self -> mapping = nil;

r_frame = self;

return true;

}

static MCScriptFrame *MCScriptDestroyFrame(MCScriptFrame *self)

{

MCScriptFrame *t_caller;

t_caller = self -> caller;

for(int i = 0; i < self -> handler -> slot_count; i++)

MCValueRelease(self -> slots[i]);

MCScriptReleaseInstance(self -> instance);

MCMemoryDeleteArray(self -> slots);

MCMemoryDeleteArray(self -> mapping);

MCMemoryDelete(self);

return t_caller;

}

static inline void MCScriptBytecodeDecodeOp(byte_t*& x_bytecode_ptr, MCScriptBytecodeOp& r_op, uindex_t& r_arity)

{

byte_t t_op_byte;

t_op_byte = *x_bytecode_ptr++;

// The lower nibble is the bytecode operation.

MCScriptBytecodeOp t_op;

t_op = (MCScriptBytecodeOp)(t_op_byte & 0xf);

// The upper nibble is the arity.

uindex_t t_arity;

t_arity = (t_op_byte >> 4);

// If the arity is 15, then overflow to a subsequent byte.

if (t_arity == 15)

t_arity += *x_bytecode_ptr++;

r_op = t_op;

r_arity = t_arity;

}

// TODO: Make this better for negative numbers.

static inline uindex_t MCScriptBytecodeDecodeArgument(byte_t*& x_bytecode_ptr)

{

uindex_t t_value;

t_value = 0;

int t_shift;

t_shift = 0;

for(;;)

{

byte_t t_next;

t_next = *x_bytecode_ptr++;

t_value |= (t_next & 0x7f) << t_shift;

if ((t_next & 0x80) == 0)

break;

t_shift += 7;

}

return t_value;

}

static inline void MCScriptResolveDefinitionInFrame(MCScriptFrame *p_frame, uindex_t p_index, MCScriptInstanceRef& r_instance, MCScriptDefinition*& r_definition)

{

MCScriptInstanceRef t_instance;

t_instance = p_frame -> instance;

MCScriptDefinition *t_definition;

t_definition = t_instance -> module -> definitions[p_index];

if (t_definition -> kind == kMCScriptDefinitionKindExternal)

{

MCScriptExternalDefinition *t_ext_def;

t_ext_def = static_cast<MCScriptExternalDefinition *>(t_definition);

MCScriptImportedDefinition *t_import_def;

t_import_def = &t_instance -> module -> imported_definitions[t_ext_def -> index];

t_instance = t_import_def -> resolved_module -> shared_instance;

t_definition = t_import_def -> resolved_definition;

}

r_instance = t_instance;

r_definition = t_definition;

}

static inline MCTypeInfoRef MCScriptGetRegisterTypeInFrame(MCScriptFrame *p_frame, int p_register)

{

/* LOAD CHECK */ __MCScriptAssert__(MCScriptIsRegisterValidInFrame(p_frame, p_register),

"register out of range on fetch register type");

MCTypeInfoRef t_handler_type;

t_handler_type = p_frame -> instance -> module -> types[p_frame -> handler -> type] -> typeinfo;

uindex_t t_parameter_count;

t_parameter_count = MCHandlerTypeInfoGetParameterCount(t_handler_type);

if (p_register < t_parameter_count)

return MCHandlerTypeInfoGetParameterType(t_handler_type, p_register);

if (p_register < t_parameter_count + p_frame -> handler -> local_type_count)

return p_frame -> instance -> module -> types[p_frame -> handler -> local_types[p_register - t_parameter_count]] -> typeinfo;

return nil;

}

static bool MCScriptGetRegisterTypeIsOptionalInFrame(MCScriptFrame *p_frame, int p_register)

{

/* LOAD CHECK */ __MCScriptAssert__(MCScriptIsRegisterValidInFrame(p_frame, p_register),

"register out of range on fetch register type is optional");

MCTypeInfoRef t_type;

t_type = MCScriptGetRegisterTypeInFrame(p_frame, p_register);

if (t_type == nil)

return true;

MCResolvedTypeInfo t_resolved_type;

if (!MCTypeInfoResolve(t_type, t_resolved_type))

return true; /* RESOLVE UNCHECKED */

return t_resolved_type . is_optional;

}

static inline MCValueRef MCScriptFetchFromRegisterInFrame(MCScriptFrame *p_frame, int p_register)

{

/* LOAD CHECK */ __MCScriptAssert__(MCScriptIsRegisterValidInFrame(p_frame, p_register),

"register out of range on fetch");

return p_frame -> slots[p_register];

}

static inline void MCScriptStoreToRegisterInFrameAndRelease(MCScriptFrame *p_frame, int p_register, MCValueRef p_value)

{

/* LOAD CHECK */ __MCScriptAssert__(MCScriptIsRegisterValidInFrame(p_frame, p_register),

"register out of range on store");

if (p_frame -> slots[p_register] != p_value)

{

MCValueRelease(p_frame -> slots[p_register]);

p_frame -> slots[p_register] = p_value;

}

}

static inline void MCScriptStoreToRegisterInFrame(MCScriptFrame *p_frame, int p_register, MCValueRef p_value)

{

/* LOAD CHECK */ __MCScriptAssert__(MCScriptIsRegisterValidInFrame(p_frame, p_register),

"register out of range on store");

if (p_frame -> slots[p_register] != p_value)

{

MCValueRelease(p_frame -> slots[p_register]);

p_frame -> slots[p_register] = MCValueRetain(p_value);

}

}

static bool MCScriptCheckedFetchFromRegisterInFrame(MCScriptFrame *p_frame, int p_register, MCValueRef& r_value)

{

MCValueRef t_value;

t_value = MCScriptFetchFromRegisterInFrame(p_frame, p_register);

if (t_value == kMCNull &&

!MCScriptGetRegisterTypeIsOptionalInFrame(p_frame, p_register))

return MCScriptThrowLocalVariableUsedBeforeDefinedError(p_frame -> instance -> module, p_frame -> handler, p_register);

r_value = t_value;

return true;

}

static bool MCScriptCheckedStoreToRegisterInFrame(MCScriptFrame *p_frame, int p_register, MCValueRef p_value)

{

MCTypeInfoRef t_type;

t_type = MCScriptGetRegisterTypeInFrame(p_frame, p_register);

if (t_type != nil &&

!MCTypeInfoConforms(MCValueGetTypeInfo(p_value), t_type))

return MCScriptThrowInvalidValueForLocalVariableError(p_frame -> instance -> module, p_frame -> handler, p_register, t_type, p_value);

MCScriptStoreToRegisterInFrame(p_frame, p_register, p_value);

return true;

}

static inline MCValueRef MCScriptFetchConstantInFrame(MCScriptFrame *p_frame, int p_index)

{

/* LOAD CHECK */ __MCScriptAssert__(MCScriptIsConstantValidInFrame(p_frame, p_index),

"constant out of range on fetch");

return p_frame -> instance -> module -> values[p_index];

}

static bool MCScriptPerformScriptInvoke(MCScriptFrame*& x_frame, byte_t*& x_next_bytecode, MCScriptInstanceRef p_instance, MCScriptHandlerDefinition *p_handler, uindex_t *p_arguments, uindex_t p_arity)

{

MCTypeInfoRef t_signature;

t_signature = p_instance -> module -> types[p_handler -> type] -> typeinfo;

// If the signature of the handler includes a return value, then the first

// argument will be the register to place it in.

uindex_t t_result_reg;

t_result_reg = p_arguments[0];

p_arity -= 1;

p_arguments += 1;

// If the number of remaining arguments is not the same as the parameter count then

// it is an error.

if (MCHandlerTypeInfoGetParameterCount(t_signature) != p_arity)

return MCScriptThrowWrongNumberOfArgumentsForInvokeError(p_instance -> module, p_handler, p_arity);

// Check that the arguments all conform to the required types and that we aren't

// using any local variables before they have been assigned.

for(uindex_t i = 0; i < p_arity; i++)

{

// Out parameters are initialized to undefined, so we don't care about

// their values on input.

if (MCHandlerTypeInfoGetParameterMode(t_signature, i) == kMCHandlerTypeFieldModeOut)

continue;

MCValueRef t_value;

if (!MCScriptCheckedFetchFromRegisterInFrame(x_frame, p_arguments[i], t_value))

return false;

MCTypeInfoRef t_type;

t_type = MCHandlerTypeInfoGetParameterType(t_signature, i);

if (!MCTypeInfoConforms(MCValueGetTypeInfo(t_value), t_type))

return MCScriptThrowInvalidValueForArgumentError(p_instance -> module, p_handler, i, t_type, t_value);

}

// Create a (stack) frame for the handler.

MCScriptFrame *t_callee;

if (!MCScriptCreateFrame(x_frame, p_instance, p_handler, t_callee))

return false;

// We need to record a mapping vector if we have any out parameters.

bool t_needs_mapping;

t_needs_mapping = false;

// Fetch the parameter values and store them in the appropriate slots. The

// parameters are always the first 'arity' slots in the frame.

for(int i = 0; i < MCHandlerTypeInfoGetParameterCount(t_signature); i++)

{

MCHandlerTypeFieldMode t_mode;

t_mode = MCHandlerTypeInfoGetParameterMode(t_signature, i);

MCValueRef t_value;

if (t_mode != kMCHandlerTypeFieldModeOut)

t_value = MCScriptFetchFromRegisterInFrame(x_frame, p_arguments[i]);

else

t_value = kMCNull;

if (t_mode != kMCHandlerTypeFieldModeIn)

t_needs_mapping = true;

MCValueAssign(t_callee -> slots[i], t_value);

}

if (t_needs_mapping)

{

if (!MCMemoryNewArray(p_arity, t_callee -> mapping))

{

MCScriptDestroyFrame (t_callee);

return false;

}

MCMemoryCopy(t_callee -> mapping, p_arguments, sizeof(int) * p_arity);

}

t_callee -> result = t_result_reg;

x_frame = t_callee;

x_next_bytecode = x_frame -> instance -> module -> bytecode + x_frame -> address;

return true;

}

// This method resolves the binding string in the foreign function. The format is:

// [lang:][library>][class.]function[!calling]

//

// lang - one of c, cpp, objc or java. If not present, it is taken to be c.

// library - the library to load the symbol from. If not present, it is taken to be the

// main executable.

// class - only valid for cpp, objc, or java. If not present, it is taken to be no class.

// function - the name of the function or method.

// calling - the calling convention, if not present it is taken to be the platform default.

//

// The calling conventions are:

// default (sysv on 32-bit unix intel, unix64 on 64-bit unix intel, win64 on 64-bit windows, cdelc on 32-bit windows)

// stdcall (windows 32-bit)

// thiscall (windows 32-bit)

// fastcall (windows 32-bit)

// cdecl (windows 32-bit)

// pascal (windows 32-bit)

// register (windows 32-bit)

// If a windows calling convention is specified, it is taken to be 'default' on

// other platforms.

//

static bool __split_binding(MCStringRef& x_string, codepoint_t p_char, MCStringRef& r_field)

{

MCStringRef t_head, t_tail;

if (!MCStringDivideAtChar(x_string, p_char, kMCStringOptionCompareExact, t_head, t_tail))

return false;

if (!MCStringIsEmpty(t_tail))

{

r_field = t_head;

MCValueRelease(x_string);

x_string = t_tail;

}

else

{

MCValueRelease(x_string);

MCValueRelease(t_tail);

x_string = t_head;

}

return true;

}

static bool MCScriptPlatformLoadSharedLibrary(MCStringRef p_path, void*& r_handle)

{

#if defined(_WIN32)

HMODULE t_module;

MCAutoStringRefAsWString t_library_wstr;

if (!t_library_wstr.Lock(p_path))

return false;

t_module = LoadLibraryW(*t_library_wstr);

if (t_module == NULL)

return false;

r_handle = (void *)t_module;

#else

MCAutoStringRefAsUTF8String t_utf8_library;

if (!t_utf8_library.Lock(p_path))

return false;

void *t_module;

t_module = dlopen(*t_utf8_library, RTLD_LAZY);

if (t_module == NULL)

return false;

r_handle = (void *)t_module;

#endif

return true;

}

static bool MCScriptPlatformLoadSharedLibraryFunction(void *p_module, MCStringRef p_function, void*& r_pointer)

{

MCAutoStringRefAsCString t_function_name;

if (!t_function_name.Lock(p_function))

return false;

void *t_pointer;

#if defined(_WIN32)

t_pointer = GetProcAddress((HMODULE)p_module, *t_function_name);

#else

t_pointer = dlsym(p_module, *t_function_name);

#endif

r_pointer = t_pointer;

return true;

}

static bool MCScriptLoadSharedLibrary(MCScriptModuleRef p_module, MCStringRef p_library, void*& r_handle)

{

// If there is no library name then we resolve to the executable module.

if (MCStringIsEmpty(p_library))

{

#if defined(_WIN32)

r_handle = GetModuleHandle(NULL);

#elif defined(TARGET_SUBPLATFORM_ANDROID)

r_handle = dlopen("librevandroid.so", 0);

#else

r_handle = dlopen(NULL, 0);

#endif

return true;

}

// If there is no slash in the name, we try to resolve based on the module.

uindex_t t_offset;

if (!MCStringFirstIndexOfChar(p_library, '/', 0, kMCStringOptionCompareExact, t_offset))

{

MCAutoStringRef t_mapped_library;