/[svn]/linuxsampler/trunk/src/scriptvm/common.h
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Wed Jul 13 15:51:06 2016 UTC (7 years, 8 months ago) by schoenebeck
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* NKSP: Implemented built-in script variable "$KSP_TIMER".
* NKSP: Implemented built-in script variable "$NKSP_REAL_TIMER".
* NKSP: Implemented built-in script variable "$NKSP_PERF_TIMER".
* NKSP: Implemented built-in script variable "$ENGINE_UPTIME".
* Bumped version (2.0.0.svn14).

1 schoenebeck 2581 /*
2 schoenebeck 2871 * Copyright (c) 2014-2016 Christian Schoenebeck
3 schoenebeck 2581 *
4     * http://www.linuxsampler.org
5     *
6     * This file is part of LinuxSampler and released under the same terms.
7     * See README file for details.
8     */
9    
10     // This header defines data types shared between the VM core implementation
11     // (inside the current source directory) and other parts of the sampler
12     // (located at other source directories).
13    
14     #ifndef LS_INSTR_SCRIPT_PARSER_COMMON_H
15     #define LS_INSTR_SCRIPT_PARSER_COMMON_H
16    
17     #include "../common/global.h"
18 schoenebeck 2588 #include <vector>
19 schoenebeck 2594 #include <map>
20     #include <stddef.h> // offsetof()
21 schoenebeck 2581
22     namespace LinuxSampler {
23 schoenebeck 2727
24     /**
25     * Identifies the type of a noteworthy issue identified by the script
26     * parser. That's either a parser error or parser warning.
27     */
28 schoenebeck 2581 enum ParserIssueType_t {
29 schoenebeck 2727 PARSER_ERROR, ///< Script parser encountered an error, the script cannot be executed.
30     PARSER_WARNING ///< Script parser encountered a warning, the script may be executed if desired, but the script may not necessarily behave as originally intended by the script author.
31 schoenebeck 2581 };
32    
33 schoenebeck 2727 /** @brief Expression's data type.
34     *
35     * Identifies to which data type an expression within a script evaluates to.
36     * This can for example reflect the data type of script function arguments,
37     * script function return values, but also the resulting data type of some
38     * mathematical formula within a script.
39     */
40 schoenebeck 2581 enum ExprType_t {
41 schoenebeck 2727 EMPTY_EXPR, ///< i.e. on invalid expressions or i.e. a function call that does not return a result value (the built-in wait() or message() functions for instance)
42     INT_EXPR, ///< integer (scalar) expression
43     INT_ARR_EXPR, ///< integer array expression
44     STRING_EXPR, ///< string expression
45     STRING_ARR_EXPR, ///< string array expression
46 schoenebeck 2581 };
47    
48 schoenebeck 2727 /** @brief Result flags of a script statement or script function call.
49     *
50     * A set of bit flags which provide informations about the success or
51     * failure of a statement within a script. That's also especially used for
52     * providing informations about success / failure of a call to a built-in
53     * script function. The virtual machine evaluates these flags during runtime
54     * to decide whether it should i.e. stop or suspend execution of a script.
55     *
56     * Since these are bit flags, these constants are bitwise combined.
57     */
58 schoenebeck 2581 enum StmtFlags_t {
59     STMT_SUCCESS = 0, ///< Function / statement was executed successfully, no error occurred.
60 schoenebeck 2727 STMT_ABORT_SIGNALLED = 1, ///< VM should stop the current callback execution (usually because of an error, but might also be without an error reason, i.e. when the built-in script function exit() was called).
61     STMT_SUSPEND_SIGNALLED = (1<<1), ///< VM supended execution, either because the script called the built-in wait() script function or because the script consumed too much execution time and was forced by the VM to be suspended for some time
62     STMT_ERROR_OCCURRED = (1<<2), ///< VM stopped execution due to some script runtime error that occurred
63 schoenebeck 2581 };
64    
65 schoenebeck 2727 /** @brief Virtual machine execution status.
66     *
67     * A set of bit flags which reflect the current overall execution status of
68     * the virtual machine concerning a certain script execution instance.
69     *
70     * Since these are bit flags, these constants are bitwise combined.
71     */
72 schoenebeck 2581 enum VMExecStatus_t {
73 schoenebeck 2727 VM_EXEC_NOT_RUNNING = 0, ///< Script is currently not executed by the VM.
74     VM_EXEC_RUNNING = 1, ///< The VM is currently executing the script.
75     VM_EXEC_SUSPENDED = (1<<1), ///< Script is currently suspended by the VM, either because the script called the built-in wait() script function or because the script consumed too much execution time and was forced by the VM to be suspended for some time.
76     VM_EXEC_ERROR = (1<<2), ///< A runtime error occurred while executing the script (i.e. a call to some built-in script function failed).
77 schoenebeck 2581 };
78    
79 schoenebeck 2879 /** @brief Script event handler type.
80     *
81     * Identifies one of the possible event handler callback types defined by
82     * the NKSP script language.
83     */
84     enum VMEventHandlerType_t {
85     VM_EVENT_HANDLER_INIT, ///< Initilization event handler, that is script's "on init ... end on" code block.
86     VM_EVENT_HANDLER_NOTE, ///< Note event handler, that is script's "on note ... end on" code block.
87     VM_EVENT_HANDLER_RELEASE, ///< Release event handler, that is script's "on release ... end on" code block.
88     VM_EVENT_HANDLER_CONTROLLER, ///< Controller event handler, that is script's "on controller ... end on" code block.
89     };
90    
91 schoenebeck 2727 // just symbol prototyping
92 schoenebeck 2596 class VMIntExpr;
93     class VMStringExpr;
94 schoenebeck 2619 class VMIntArrayExpr;
95     class VMStringArrayExpr;
96 schoenebeck 2596
97 schoenebeck 2727 /** @brief Virtual machine expression
98     *
99     * This is the abstract base class for all expressions of scripts.
100     * Deriving classes must implement the abstract method exprType().
101     *
102     * An expression within a script is translated into one instance of this
103     * class. It allows a high level access for the virtual machine to evaluate
104     * and handle expressions appropriately during execution. Expressions are
105     * for example all kinds of formulas, function calls, statements or a
106     * combination of them. Most of them evaluate to some kind of value, which
107     * might be further processed as part of encompassing expressions to outer
108     * expression results and so forth.
109     */
110 schoenebeck 2581 class VMExpr {
111     public:
112 schoenebeck 2727 /**
113     * Identifies the data type to which the result of this expression
114     * evaluates to. This abstract method must be implemented by deriving
115     * classes.
116     */
117 schoenebeck 2581 virtual ExprType_t exprType() const = 0;
118 schoenebeck 2727
119     /**
120     * In case this expression is an integer expression, then this method
121     * returns a casted pointer to that VMIntExpr object. It returns NULL
122     * if this expression is not an integer expression.
123     *
124     * @b Note: type casting performed by this method is strict! That means
125     * if this expression is i.e. actually a string expression like "12",
126     * calling asInt() will @b not cast that numerical string expression to
127     * an integer expression 12 for you, instead this method will simply
128     * return NULL!
129     *
130     * @see exprType()
131     */
132 schoenebeck 2596 VMIntExpr* asInt() const;
133 schoenebeck 2727
134     /**
135     * In case this expression is a string expression, then this method
136     * returns a casted pointer to that VMStringExpr object. It returns NULL
137     * if this expression is not a string expression.
138     *
139     * @b Note: type casting performed by this method is strict! That means
140     * if this expression is i.e. actually an integer expression like 120,
141     * calling asString() will @b not cast that integer expression to a
142     * string expression "120" for you, instead this method will simply
143     * return NULL!
144     *
145     * @see exprType()
146     */
147 schoenebeck 2596 VMStringExpr* asString() const;
148 schoenebeck 2727
149     /**
150     * In case this expression is an integer array expression, then this
151     * method returns a casted pointer to that VMIntArrayExpr object. It
152     * returns NULL if this expression is not an integer array expression.
153     *
154     * @b Note: type casting performed by this method is strict! That means
155     * if this expression is i.e. an integer expression or a string
156     * expression, calling asIntArray() will @b not cast those scalar
157     * expressions to an array expression for you, instead this method will
158     * simply return NULL!
159     *
160     * @see exprType()
161     */
162 schoenebeck 2619 VMIntArrayExpr* asIntArray() const;
163 schoenebeck 2581 };
164    
165 schoenebeck 2727 /** @brief Virtual machine integer expression
166     *
167     * This is the abstract base class for all expressions inside scripts which
168     * evaluate to an integer (scalar) value. Deriving classes implement the
169     * abstract method evalInt() to return the actual integer result value of
170     * the expression.
171     */
172 schoenebeck 2581 class VMIntExpr : virtual public VMExpr {
173     public:
174 schoenebeck 2727 /**
175     * Returns the result of this expression as integer (scalar) value.
176     * This abstract method must be implemented by deriving classes.
177     */
178 schoenebeck 2581 virtual int evalInt() = 0;
179 schoenebeck 2727
180     /**
181     * Returns always INT_EXPR for instances of this class.
182     */
183     ExprType_t exprType() const OVERRIDE { return INT_EXPR; }
184 schoenebeck 2581 };
185    
186 schoenebeck 2727 /** @brief Virtual machine string expression
187     *
188     * This is the abstract base class for all expressions inside scripts which
189     * evaluate to a string value. Deriving classes implement the abstract
190     * method evalStr() to return the actual string result value of the
191     * expression.
192     */
193 schoenebeck 2581 class VMStringExpr : virtual public VMExpr {
194     public:
195 schoenebeck 2727 /**
196     * Returns the result of this expression as string value. This abstract
197     * method must be implemented by deriving classes.
198     */
199 schoenebeck 2581 virtual String evalStr() = 0;
200 schoenebeck 2727
201     /**
202     * Returns always STRING_EXPR for instances of this class.
203     */
204     ExprType_t exprType() const OVERRIDE { return STRING_EXPR; }
205 schoenebeck 2581 };
206    
207 schoenebeck 2727 /** @brief Virtual Machine Array Value Expression
208     *
209     * This is the abstract base class for all expressions inside scripts which
210     * evaluate to some kind of array value. Deriving classes implement the
211     * abstract method arraySize() to return the amount of elements within the
212     * array.
213     */
214 schoenebeck 2619 class VMArrayExpr : virtual public VMExpr {
215     public:
216 schoenebeck 2727 /**
217     * Returns amount of elements in this array. This abstract method must
218     * be implemented by deriving classes.
219     */
220 schoenebeck 2619 virtual int arraySize() const = 0;
221     };
222    
223 schoenebeck 2727 /** @brief Virtual Machine Integer Array Expression
224     *
225     * This is the abstract base class for all expressions inside scripts which
226     * evaluate to an array of integer values. Deriving classes implement the
227     * abstract methods arraySize(), evalIntElement() and assignIntElement() to
228     * access the individual integer array values.
229     */
230 schoenebeck 2619 class VMIntArrayExpr : virtual public VMArrayExpr {
231     public:
232 schoenebeck 2727 /**
233     * Returns the (scalar) integer value of the array element given by
234     * element index @a i.
235     *
236     * @param i - array element index (must be between 0 .. arraySize() - 1)
237     */
238 schoenebeck 2619 virtual int evalIntElement(uint i) = 0;
239 schoenebeck 2727
240     /**
241     * Changes the current value of an element (given by array element
242     * index @a i) of this integer array.
243     *
244     * @param i - array element index (must be between 0 .. arraySize() - 1)
245     * @param value - new integer scalar value to be assigned to that array element
246     */
247 schoenebeck 2619 virtual void assignIntElement(uint i, int value) = 0;
248 schoenebeck 2727
249     /**
250     * Returns always INT_ARR_EXPR for instances of this class.
251     */
252     ExprType_t exprType() const OVERRIDE { return INT_ARR_EXPR; }
253 schoenebeck 2619 };
254    
255 schoenebeck 2727 /** @brief Arguments (parameters) for being passed to a built-in script function.
256     *
257     * An argument or a set of arguments passed to a script function are
258     * translated by the parser to an instance of this class. This abstract
259     * interface class is used by implementations of built-in functions to
260     * obtain the individual function argument values being passed to them at
261     * runtime.
262     */
263 schoenebeck 2581 class VMFnArgs {
264     public:
265 schoenebeck 2727 /**
266     * Returns the amount of arguments going to be passed to the script
267     * function.
268     */
269 schoenebeck 2581 virtual int argsCount() const = 0;
270 schoenebeck 2727
271     /**
272     * Returns the respective argument (requested by argument index @a i) of
273     * this set of arguments. This method is called by implementations of
274     * built-in script functions to obtain the value of each function
275     * argument passed to the function at runtime.
276     *
277     * @param i - function argument index (indexed from left to right)
278     */
279 schoenebeck 2581 virtual VMExpr* arg(int i) = 0;
280     };
281    
282 schoenebeck 2727 /** @brief Result value returned from a call to a built-in script function.
283     *
284     * Implementations of built-in script functions return an instance of this
285     * object to let the virtual machine obtain the result value of the function
286     * call, which might then be further processed by the virtual machine
287     * according to the script. It also provides informations about the success
288     * or failure of the function call.
289     */
290 schoenebeck 2581 class VMFnResult {
291     public:
292 schoenebeck 2727 /**
293     * Returns the result value of the function call, represented by a high
294     * level expression object.
295     */
296 schoenebeck 2581 virtual VMExpr* resultValue() = 0;
297 schoenebeck 2727
298     /**
299     * Provides detailed informations of the success / failure of the
300     * function call. The virtual machine is evaluating the flags returned
301     * here to decide whether it must abort or suspend execution of the
302     * script at this point.
303     */
304 schoenebeck 2581 virtual StmtFlags_t resultFlags() { return STMT_SUCCESS; }
305     };
306    
307 schoenebeck 2727 /** @brief Virtual machine built-in function.
308 schoenebeck 2612 *
309     * Abstract base class for built-in script functions, defining the interface
310 schoenebeck 2727 * for all built-in script function implementations. All built-in script
311     * functions are deriving from this abstract interface class in order to
312     * provide their functionality to the virtual machine with this unified
313     * interface.
314     *
315     * The methods of this interface class provide two purposes:
316     *
317     * 1. When a script is loaded, the script parser uses the methods of this
318     * interface to check whether the script author was calling the
319     * respective built-in script function in a correct way. For example
320     * the parser checks whether the required amount of parameters were
321     * passed to the function and whether the data types passed match the
322     * data types expected by the function. If not, loading the script will
323     * be aborted with a parser error, describing to the user (i.e. script
324     * author) the precise misusage of the respective function.
325     * 2. After the script was loaded successfully and the script is executed,
326     * the virtual machine calls the exec() method of the respective built-in
327     * function to provide the actual functionality of the built-in function
328     * call.
329 schoenebeck 2612 */
330 schoenebeck 2581 class VMFunction {
331     public:
332 schoenebeck 2612 /**
333     * Script data type of the function's return value. If the function does
334 schoenebeck 2727 * not return any value (void), then it returns EMPTY_EXPR here.
335 schoenebeck 2612 */
336 schoenebeck 2581 virtual ExprType_t returnType() = 0;
337 schoenebeck 2612
338     /**
339     * Minimum amount of function arguments this function accepts. If a
340     * script is calling this function with less arguments, the script
341     * parser will throw a parser error.
342     */
343 schoenebeck 2581 virtual int minRequiredArgs() const = 0;
344 schoenebeck 2612
345     /**
346     * Maximum amount of function arguments this functions accepts. If a
347     * script is calling this function with more arguments, the script
348     * parser will throw a parser error.
349     */
350 schoenebeck 2581 virtual int maxAllowedArgs() const = 0;
351 schoenebeck 2612
352     /**
353     * Script data type of the function's @c iArg 'th function argument.
354     * The information provided here is less strong than acceptsArgType().
355     * The parser will compare argument data types provided in scripts by
356 schoenebeck 2871 * calling acceptsArgType(). The return value of argType() is used by the
357 schoenebeck 2612 * parser instead to show an appropriate parser error which data type
358     * this function usually expects as "default" data type. Reason: a
359     * function may accept multiple data types for a certain function
360     * argument and would automatically cast the passed argument value in
361     * that case to the type it actually needs.
362     *
363     * @param iArg - index of the function argument in question
364 schoenebeck 2727 * (must be between 0 .. maxAllowedArgs() - 1)
365 schoenebeck 2612 */
366 schoenebeck 2581 virtual ExprType_t argType(int iArg) const = 0;
367 schoenebeck 2612
368     /**
369     * This function is called by the parser to check whether arguments
370     * passed in scripts to this function are accepted by this function. If
371     * a script calls this function with an argument's data type not
372 schoenebeck 2727 * accepted by this function, the parser will throw a parser error. On
373     * such errors the data type returned by argType() will be used to
374     * assemble an appropriate error message regarding the precise misusage
375     * of the built-in function.
376 schoenebeck 2612 *
377     * @param iArg - index of the function argument in question
378 schoenebeck 2727 * (must be between 0 .. maxAllowedArgs() - 1)
379 schoenebeck 2612 * @param type - script data type used for this function argument by
380     * currently parsed script
381 schoenebeck 2727 * @return true if the given data type would be accepted for the
382     * respective function argument by the function
383 schoenebeck 2612 */
384 schoenebeck 2581 virtual bool acceptsArgType(int iArg, ExprType_t type) const = 0;
385 schoenebeck 2612
386     /**
387 schoenebeck 2727 * Implements the actual function execution. This exec() method is
388     * called by the VM whenever this function implementation shall be
389     * executed at script runtime. This method blocks until the function
390     * call completed.
391 schoenebeck 2612 *
392     * @param args - function arguments for executing this built-in function
393 schoenebeck 2727 * @returns function's return value (if any) and general status
394     * informations (i.e. whether the function call caused a
395     * runtime error)
396 schoenebeck 2612 */
397 schoenebeck 2581 virtual VMFnResult* exec(VMFnArgs* args) = 0;
398 schoenebeck 2612
399     /**
400 schoenebeck 2727 * Convenience method for function implementations to show warning
401     * messages during actual execution of the built-in function.
402 schoenebeck 2612 *
403 schoenebeck 2727 * @param txt - runtime warning text to be shown to user
404 schoenebeck 2612 */
405 schoenebeck 2598 void wrnMsg(const String& txt);
406 schoenebeck 2612
407     /**
408 schoenebeck 2727 * Convenience method for function implementations to show error
409     * messages during actual execution of the built-in function.
410 schoenebeck 2612 *
411 schoenebeck 2727 * @param txt - runtime error text to be shown to user
412 schoenebeck 2612 */
413 schoenebeck 2598 void errMsg(const String& txt);
414 schoenebeck 2581 };
415    
416 schoenebeck 2727 /** @brief Virtual machine relative pointer.
417     *
418 schoenebeck 2594 * POD base of VMIntRelPtr and VMInt8RelPtr structures. Not intended to be
419     * used directly. Use VMIntRelPtr or VMInt8RelPtr instead.
420 schoenebeck 2727 *
421     * @see VMIntRelPtr, VMInt8RelPtr
422 schoenebeck 2594 */
423     struct VMRelPtr {
424     void** base; ///< Base pointer.
425 schoenebeck 2727 int offset; ///< Offset (in bytes) relative to base pointer.
426 schoenebeck 2594 };
427    
428     /** @brief Pointer to built-in VM integer variable (of C/C++ type int).
429     *
430 schoenebeck 2727 * Used for defining built-in 32 bit integer script variables.
431 schoenebeck 2594 *
432     * @b CAUTION: You may only use this class for pointing to C/C++ variables
433     * of type "int" (which on most systems is 32 bit in size). If the C/C++ int
434     * variable you want to reference is only 8 bit in size, then you @b must
435     * use VMInt8RelPtr instead!
436     *
437     * For efficiency reasons the actual native C/C++ int variable is referenced
438     * by two components here. The actual native int C/C++ variable in memory
439     * is dereferenced at VM run-time by taking the @c base pointer dereference
440     * and adding @c offset bytes. This has the advantage that for a large
441     * number of built-in int variables, only one (or few) base pointer need
442     * to be re-assigned before running a script, instead of updating each
443     * built-in variable each time before a script is executed.
444     *
445     * Refer to DECLARE_VMINT() for example code.
446     *
447     * @see VMInt8RelPtr, DECLARE_VMINT()
448     */
449     struct VMIntRelPtr : VMRelPtr {
450     VMIntRelPtr() {
451     base = NULL;
452     offset = 0;
453     }
454     VMIntRelPtr(const VMRelPtr& data) {
455     base = data.base;
456     offset = data.offset;
457     }
458     virtual int evalInt() { return *(int*)&(*(uint8_t**)base)[offset]; }
459     virtual void assign(int i) { *(int*)&(*(uint8_t**)base)[offset] = i; }
460     };
461    
462     /** @brief Pointer to built-in VM integer variable (of C/C++ type int8_t).
463     *
464 schoenebeck 2727 * Used for defining built-in 8 bit integer script variables.
465 schoenebeck 2594 *
466     * @b CAUTION: You may only use this class for pointing to C/C++ variables
467     * of type "int8_t" (8 bit integer). If the C/C++ int variable you want to
468     * reference is an "int" type (which is 32 bit on most systems), then you
469     * @b must use VMIntRelPtr instead!
470     *
471     * For efficiency reasons the actual native C/C++ int variable is referenced
472     * by two components here. The actual native int C/C++ variable in memory
473     * is dereferenced at VM run-time by taking the @c base pointer dereference
474     * and adding @c offset bytes. This has the advantage that for a large
475     * number of built-in int variables, only one (or few) base pointer need
476     * to be re-assigned before running a script, instead of updating each
477     * built-in variable each time before a script is executed.
478     *
479     * Refer to DECLARE_VMINT() for example code.
480     *
481     * @see VMIntRelPtr, DECLARE_VMINT()
482     */
483     struct VMInt8RelPtr : VMIntRelPtr {
484     VMInt8RelPtr() : VMIntRelPtr() {}
485     VMInt8RelPtr(const VMRelPtr& data) : VMIntRelPtr(data) {}
486     virtual int evalInt() OVERRIDE {
487     return *(uint8_t*)&(*(uint8_t**)base)[offset];
488     }
489     virtual void assign(int i) OVERRIDE {
490     *(uint8_t*)&(*(uint8_t**)base)[offset] = i;
491     }
492     };
493    
494     /**
495     * Convenience macro for initializing VMIntRelPtr and VMInt8RelPtr
496 schoenebeck 2727 * structures. Usage example:
497 schoenebeck 2594 * @code
498     * struct Foo {
499 schoenebeck 2727 * uint8_t a; // native representation of a built-in integer script variable
500     * int b; // native representation of another built-in integer script variable
501     * int c; // native representation of another built-in integer script variable
502     * uint8_t d; // native representation of another built-in integer script variable
503 schoenebeck 2594 * };
504     *
505 schoenebeck 2727 * // initializing the built-in script variables to some values
506     * Foo foo1 = (Foo) { 1, 2000, 3000, 4 };
507     * Foo foo2 = (Foo) { 5, 6000, 7000, 8 };
508 schoenebeck 2594 *
509     * Foo* pFoo;
510     *
511 schoenebeck 2727 * VMInt8RelPtr varA = DECLARE_VMINT(pFoo, class Foo, a);
512     * VMIntRelPtr varB = DECLARE_VMINT(pFoo, class Foo, b);
513     * VMIntRelPtr varC = DECLARE_VMINT(pFoo, class Foo, c);
514     * VMInt8RelPtr varD = DECLARE_VMINT(pFoo, class Foo, d);
515 schoenebeck 2594 *
516     * pFoo = &foo1;
517 schoenebeck 2727 * printf("%d\n", varA->evalInt()); // will print 1
518     * printf("%d\n", varB->evalInt()); // will print 2000
519     * printf("%d\n", varC->evalInt()); // will print 3000
520     * printf("%d\n", varD->evalInt()); // will print 4
521 schoenebeck 2594 *
522 schoenebeck 2727 * // same printf() code, just with pFoo pointer being changed ...
523     *
524 schoenebeck 2594 * pFoo = &foo2;
525 schoenebeck 2727 * printf("%d\n", varA->evalInt()); // will print 5
526     * printf("%d\n", varB->evalInt()); // will print 6000
527     * printf("%d\n", varC->evalInt()); // will print 7000
528     * printf("%d\n", varD->evalInt()); // will print 8
529 schoenebeck 2594 * @endcode
530 schoenebeck 2727 * As you can see above, by simply changing one single pointer, you can
531     * remap a huge bunch of built-in integer script variables to completely
532     * different native values/native variables. Which especially reduces code
533     * complexity inside the sampler engines which provide the actual script
534     * functionalities.
535 schoenebeck 2594 */
536     #define DECLARE_VMINT(basePtr, T_struct, T_member) ( \
537     (VMRelPtr) { \
538     (void**) &basePtr, \
539     offsetof(T_struct, T_member) \
540     } \
541     ) \
542    
543     /** @brief Built-in VM 8 bit integer array variable.
544     *
545 schoenebeck 2727 * Used for defining built-in integer array script variables (8 bit per
546     * array element). Currently there is no support for any other kind of array
547     * type. So all integer arrays of scripts use 8 bit data types.
548 schoenebeck 2594 */
549     struct VMInt8Array {
550     int8_t* data;
551     int size;
552    
553     VMInt8Array() : data(NULL), size(0) {}
554     };
555    
556 schoenebeck 2942 /** @brief Dynamically executed variable (abstract base class).
557     *
558     * Interface for the implementation of a dynamically generated content of
559     * a built-in script variable. Most built-in variables are simply pointers
560     * to some native location in memory. So when a script reads them, the
561     * memory location is simply read to get the value of the variable. A
562     * dynamic variable however is not simply a memory location. For each access
563     * to a dynamic variable some native code is executed to actually generate
564     * and provide the content (value) of this type of variable.
565     */
566     class VMDynVar : virtual public VMExpr {
567     public:
568     /**
569     * Whether a script may modify the content of this dynamic variable by
570     * assigning a new value to it.
571     *
572     * @see isConstExpr(), assign()
573     */
574     virtual bool isAssignable() const = 0;
575    
576     /**
577     * Returns true in case this dynamic variable can be considered to be a
578     * constant expression. A constant expression will retain the same value
579     * throughout the entire life time of a script and the expression's
580     * constant value may be evaluated already at script parse time, which
581     * may result in performance benefits during script runtime.
582     *
583     * However due to the "dynamic" behavior of dynamic variables, almost
584     * all dynamic variables are probably not constant expressions. That's
585     * why this method returns @c false by default. If you are really sure
586     * that your dynamic variable implementation can be considered a
587     * constant expression then you may override this method and return
588     * @c true instead. Note that when you return @c true here, your
589     * dynamic variable will really just be executed once; and exectly
590     * already when the script is loaded!
591     *
592     * As an example you may implement a "constant" built-in dynamic
593     * variable that checks for a certain operating system feature and
594     * returns the result of that OS feature check as content (value) of
595     * this dynamic variable. Since the respective OS feature might become
596     * available/unavailable after OS updates, software migration, etc. the
597     * OS feature check should at least be performed once each time the
598     * application is launched. And since the OS feature check might take a
599     * certain amount of execution time, it might make sense to only
600     * perform the check if the respective variable name is actually
601     * referenced at all in the script to be loaded. Note that the dynamic
602     * variable will still be evaluated again though if the script is
603     * loaded again. So it is up to you to probably cache the result in the
604     * implementation of your dynamic variable.
605     *
606     * On doubt, please rather consider to use a constant built-in script
607     * variable instead of implementing a "constant" dynamic variable, due
608     * to the runtime overhead a dynamic variable may cause.
609     *
610     * @see isAssignable()
611     */
612     virtual bool isConstExpr() const { return false; }
613    
614     /**
615     * In case this dynamic variable is assignable, the new value (content)
616     * to be assigned to this dynamic variable.
617     *
618     * By default this method does nothing. Override and implement this
619     * method in your subclass in case your dynamic variable allows to
620     * assign a new value by script.
621     *
622     * @param expr - new value to be assigned to this variable
623     */
624     virtual void assign(VMExpr* expr) {}
625     };
626    
627     /** @brief Dynamically executed variable (of integer data type).
628     *
629     * This is the base class for all built-in integer script variables whose
630     * variable content needs to be provided dynamically by executable native
631     * code on each script variable access.
632     */
633     class VMDynIntVar : virtual public VMDynVar, virtual public VMIntExpr {
634     public:
635     };
636    
637     /** @brief Dynamically executed variable (of string data type).
638     *
639     * This is the base class for all built-in string script variables whose
640     * variable content needs to be provided dynamically by executable native
641     * code on each script variable access.
642     */
643     class VMDynStringVar : virtual public VMDynVar, virtual public VMStringExpr {
644     public:
645     };
646    
647 schoenebeck 2612 /** @brief Provider for built-in script functions and variables.
648     *
649 schoenebeck 2727 * Abstract base class defining the high-level interface for all classes
650     * which add and implement built-in script functions and built-in script
651     * variables.
652 schoenebeck 2612 */
653 schoenebeck 2581 class VMFunctionProvider {
654     public:
655 schoenebeck 2612 /**
656     * Returns pointer to the built-in function with the given function
657 schoenebeck 2727 * @a name, or NULL if there is no built-in function with that function
658     * name.
659 schoenebeck 2612 *
660 schoenebeck 2727 * @param name - function name (i.e. "wait" or "message" or "exit", etc.)
661 schoenebeck 2612 */
662 schoenebeck 2581 virtual VMFunction* functionByName(const String& name) = 0;
663 schoenebeck 2612
664     /**
665     * Returns a variable name indexed map of all built-in script variables
666 schoenebeck 2727 * which point to native "int" scalar (usually 32 bit) variables.
667 schoenebeck 2612 */
668 schoenebeck 2594 virtual std::map<String,VMIntRelPtr*> builtInIntVariables() = 0;
669 schoenebeck 2612
670     /**
671 schoenebeck 2727 * Returns a variable name indexed map of all built-in script integer
672     * array variables with array element type "int8_t" (8 bit).
673 schoenebeck 2612 */
674 schoenebeck 2594 virtual std::map<String,VMInt8Array*> builtInIntArrayVariables() = 0;
675 schoenebeck 2612
676     /**
677     * Returns a variable name indexed map of all built-in constant script
678     * variables, which never change their value at runtime.
679     */
680 schoenebeck 2594 virtual std::map<String,int> builtInConstIntVariables() = 0;
681 schoenebeck 2942
682     /**
683     * Returns a variable name indexed map of all built-in dynamic variables,
684     * which are not simply data stores, rather each one of them executes
685     * natively to provide or alter the respective script variable data.
686     */
687     virtual std::map<String,VMDynVar*> builtInDynamicVariables() = 0;
688 schoenebeck 2581 };
689    
690 schoenebeck 2594 /** @brief Execution state of a virtual machine.
691     *
692     * An instance of this abstract base class represents exactly one execution
693     * state of a virtual machine. This encompasses most notably the VM
694 schoenebeck 2612 * execution stack, and VM polyphonic variables. It does not contain global
695 schoenebeck 2727 * variables. Global variables are contained in the VMParserContext object.
696 schoenebeck 2612 * You might see a VMExecContext object as one virtual thread of the virtual
697     * machine.
698 schoenebeck 2594 *
699 schoenebeck 2612 * In contrast to a VMParserContext, a VMExecContext is not tied to a
700     * ScriptVM instance. Thus you can use a VMExecContext with different
701     * ScriptVM instances, however not concurrently at the same time.
702     *
703 schoenebeck 2594 * @see VMParserContext
704     */
705 schoenebeck 2581 class VMExecContext {
706     public:
707     virtual ~VMExecContext() {}
708 schoenebeck 2727
709     /**
710     * In case the script was suspended for some reason, this method returns
711     * the amount of microseconds before the script shall continue its
712     * execution. Note that the virtual machine itself does never put its
713     * own execution thread(s) to sleep. So the respective class (i.e. sampler
714     * engine) which is using the virtual machine classes here, must take
715     * care by itself about taking time stamps, determining the script
716     * handlers that shall be put aside for the requested amount of
717 schoenebeck 2871 * microseconds, indicated by this method by comparing the time stamps in
718 schoenebeck 2727 * real-time, and to continue passing the respective handler to
719     * ScriptVM::exec() as soon as its suspension exceeded, etc. Or in other
720     * words: all classes in this directory never have an idea what time it
721     * is.
722     *
723     * You should check the return value of ScriptVM::exec() to determine
724     * whether the script was actually suspended before calling this method
725     * here.
726     *
727     * @see ScriptVM::exec()
728     */
729 schoenebeck 2581 virtual int suspensionTimeMicroseconds() const = 0;
730     };
731    
732 schoenebeck 2645 /** @brief Script callback for a certain event.
733     *
734     * Represents a script callback for a certain event, i.e.
735 schoenebeck 2727 * "on note ... end on" code block.
736 schoenebeck 2645 */
737 schoenebeck 2581 class VMEventHandler {
738     public:
739 schoenebeck 2645 /**
740 schoenebeck 2879 * Type of this event handler, which identifies its purpose. For example
741     * for a "on note ... end on" script callback block,
742     * @c VM_EVENT_HANDLER_NOTE would be returned here.
743     */
744     virtual VMEventHandlerType_t eventHandlerType() const = 0;
745    
746     /**
747 schoenebeck 2645 * Name of the event handler which identifies its purpose. For example
748     * for a "on note ... end on" script callback block, the name "note"
749     * would be returned here.
750     */
751 schoenebeck 2581 virtual String eventHandlerName() const = 0;
752 schoenebeck 2645
753     /**
754     * Whether or not the event handler makes any use of so called
755     * "polyphonic" variables.
756     */
757     virtual bool isPolyphonic() const = 0;
758 schoenebeck 2581 };
759    
760 schoenebeck 2727 /**
761     * Encapsulates a noteworty parser issue. This encompasses the type of the
762     * issue (either a parser error or parser warning), a human readable
763     * explanation text of the error or warning and the location of the
764     * encountered parser issue within the script.
765     */
766 schoenebeck 2581 struct ParserIssue {
767 schoenebeck 2727 String txt; ///< Human readable explanation text of the parser issue.
768 schoenebeck 2889 int firstLine; ///< The first line number within the script where this issue was encountered (indexed with 1 being the very first line).
769     int lastLine; ///< The last line number within the script where this issue was encountered.
770     int firstColumn; ///< The first column within the script where this issue was encountered (indexed with 1 being the very first column).
771     int lastColumn; ///< The last column within the script where this issue was encountered.
772 schoenebeck 2727 ParserIssueType_t type; ///< Whether this issue is either a parser error or just a parser warning.
773 schoenebeck 2581
774 schoenebeck 2727 /**
775     * Print this issue out to the console (stdio).
776     */
777 schoenebeck 2581 inline void dump() {
778     switch (type) {
779     case PARSER_ERROR:
780 schoenebeck 2889 printf("[ERROR] line %d, column %d: %s\n", firstLine, firstColumn, txt.c_str());
781 schoenebeck 2581 break;
782     case PARSER_WARNING:
783 schoenebeck 2889 printf("[Warning] line %d, column %d: %s\n", firstLine, firstColumn, txt.c_str());
784 schoenebeck 2581 break;
785     }
786     }
787 schoenebeck 2727
788     /**
789     * Returns true if this issue is a parser error. In this case the parsed
790     * script may not be executed!
791     */
792 schoenebeck 2581 inline bool isErr() const { return type == PARSER_ERROR; }
793 schoenebeck 2727
794     /**
795     * Returns true if this issue is just a parser warning. A parsed script
796     * that only raises warnings may be executed if desired, however the
797     * script may not behave exactly as intended by the script author.
798     */
799 schoenebeck 2581 inline bool isWrn() const { return type == PARSER_WARNING; }
800     };
801    
802 schoenebeck 2727 /**
803     * Convenience function used for converting an ExprType_t constant to a
804     * string, i.e. for generating error message by the parser.
805     */
806 schoenebeck 2581 inline String typeStr(const ExprType_t& type) {
807     switch (type) {
808     case EMPTY_EXPR: return "empty";
809     case INT_EXPR: return "integer";
810     case INT_ARR_EXPR: return "integer array";
811     case STRING_EXPR: return "string";
812     case STRING_ARR_EXPR: return "string array";
813     }
814     return "invalid";
815     }
816    
817 schoenebeck 2594 /** @brief Virtual machine representation of a script.
818     *
819     * An instance of this abstract base class represents a parsed script,
820 schoenebeck 2727 * translated into a virtual machine tree. You should first check if there
821     * were any parser errors. If there were any parser errors, you should
822     * refrain from executing the virtual machine. Otherwise if there were no
823     * parser errors (i.e. only warnings), then you might access one of the
824     * script's event handlers by i.e. calling eventHandlerByName() and pass the
825     * respective event handler to the ScriptVM class (or to one of the ScriptVM
826 schoenebeck 2594 * descendants) for execution.
827     *
828 schoenebeck 2727 * @see VMExecContext, ScriptVM
829 schoenebeck 2594 */
830 schoenebeck 2588 class VMParserContext {
831     public:
832     virtual ~VMParserContext() {}
833 schoenebeck 2727
834     /**
835     * Returns all noteworthy issues encountered when the script was parsed.
836     * These are parser errors and parser warnings.
837     */
838 schoenebeck 2588 virtual std::vector<ParserIssue> issues() const = 0;
839 schoenebeck 2727
840     /**
841     * Same as issues(), but this method only returns parser errors.
842     */
843 schoenebeck 2588 virtual std::vector<ParserIssue> errors() const = 0;
844 schoenebeck 2727
845     /**
846     * Same as issues(), but this method only returns parser warnings.
847     */
848 schoenebeck 2588 virtual std::vector<ParserIssue> warnings() const = 0;
849 schoenebeck 2727
850     /**
851     * Returns the translated virtual machine representation of an event
852     * handler block (i.e. "on note ... end on" code block) within the
853     * parsed script. This translated representation of the event handler
854     * can be executed by the virtual machine.
855     *
856     * @param index - index of the event handler within the script
857     */
858 schoenebeck 2588 virtual VMEventHandler* eventHandler(uint index) = 0;
859 schoenebeck 2727
860     /**
861     * Same as eventHandler(), but this method returns the event handler by
862     * its name. So for a "on note ... end on" code block of the parsed
863     * script you would pass "note" for argument @a name here.
864     *
865     * @param name - name of the event handler (i.e. "init", "note",
866     * "controller", "release")
867     */
868 schoenebeck 2588 virtual VMEventHandler* eventHandlerByName(const String& name) = 0;
869     };
870    
871 schoenebeck 2885 class SourceToken;
872    
873     /** @brief Recognized token of a script's source code.
874     *
875     * Represents one recognized token of a script's source code, for example
876     * a keyword, variable name, etc. and it provides further informations about
877     * that particular token, i.e. the precise location (line and column) of the
878     * token within the original script's source code.
879     *
880     * This class is not actually used by the sampler itself. It is rather
881     * provided for external script editor applications. Primary purpose of
882     * this class is syntax highlighting for external script editors.
883     */
884     class VMSourceToken {
885     public:
886     VMSourceToken();
887     VMSourceToken(SourceToken* ct);
888     VMSourceToken(const VMSourceToken& other);
889     virtual ~VMSourceToken();
890    
891     // original text of this token as it is in the script's source code
892     String text() const;
893    
894     // position of token in script
895 schoenebeck 2889 int firstLine() const; ///< First line this source token is located at in script source code (indexed with 0 being the very first line).
896     int firstColumn() const; ///< Last line this source token is located at in script source code.
897 schoenebeck 2885
898     // base types
899     bool isEOF() const;
900     bool isNewLine() const;
901     bool isKeyword() const;
902     bool isVariableName() const;
903     bool isIdentifier() const;
904     bool isNumberLiteral() const;
905     bool isStringLiteral() const;
906     bool isComment() const;
907     bool isPreprocessor() const;
908     bool isOther() const;
909    
910     // extended types
911     bool isIntegerVariable() const;
912     bool isStringVariable() const;
913     bool isArrayVariable() const;
914     bool isEventHandlerName() const;
915    
916     VMSourceToken& operator=(const VMSourceToken& other);
917    
918     private:
919     SourceToken* m_token;
920     };
921    
922 schoenebeck 2581 } // namespace LinuxSampler
923    
924     #endif // LS_INSTR_SCRIPT_PARSER_COMMON_H

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