src/scriptvm/ScriptVM.cpp

/*
 * Copyright (c) 2014 - 2016 Christian Schoenebeck
 *
 * http://www.linuxsampler.org
 *
 * This file is part of LinuxSampler and released under the same terms.
 * See README file for details.
 */

#include "ScriptVM.h"

#include <string.h>
#include <assert.h>
#include "../common/global_private.h"
#include "tree.h"
#include "CoreVMFunctions.h"
#include "CoreVMDynVars.h"
#include "editor/NkspScanner.h"

#define DEBUG_SCRIPTVM_CORE 0

int InstrScript_parse(LinuxSampler::ParserContext*);

namespace LinuxSampler {

    static void _printIndents(int n) {
        for (int i = 0; i < n; ++i) printf("  ");
        fflush(stdout);
    }

    static int _requiredMaxStackSizeFor(Statement* statement, int depth = 0) {
        if (!statement) return 1;

        switch (statement->statementType()) {
            case STMT_LEAF:
                #if DEBUG_SCRIPTVM_CORE
                _printIndents(depth);
                printf("-> STMT_LEAF\n");
                #endif
                return 1;

            case STMT_LIST: {
                #if DEBUG_SCRIPTVM_CORE
                _printIndents(depth);
                printf("-> STMT_LIST\n");
                #endif
                Statements* stmts = (Statements*) statement;
                int max = 0;
                for (int i = 0; stmts->statement(i); ++i) {
                    int size = _requiredMaxStackSizeFor( stmts->statement(i), depth+1 );
                    if (max < size) max = size;
                }
                return max + 1;
            }

            case STMT_BRANCH: {
                #if DEBUG_SCRIPTVM_CORE
                _printIndents(depth);
                printf("-> STMT_BRANCH\n");
                #endif
                BranchStatement* branchStmt = (BranchStatement*) statement;
                int max = 0;
                for (int i = 0; branchStmt->branch(i); ++i) {
                    int size = _requiredMaxStackSizeFor( branchStmt->branch(i), depth+1 );
                    if (max < size) max = size;
                }
                return max + 1;
            }

            case STMT_LOOP: {
                #if DEBUG_SCRIPTVM_CORE
                _printIndents(depth);
                printf("-> STMT_LOOP\n");
                #endif
                While* whileStmt = (While*) statement;
                if (whileStmt->statements())
                    return _requiredMaxStackSizeFor( whileStmt->statements() ) + 1;
                else
                    return 1;
            }
        }

        return 1; // actually just to avoid compiler warning
    }

    static int _requiredMaxStackSizeFor(EventHandlers* handlers) {
        int max = 1;
        for (int i = 0; i < handlers->size(); ++i) {
            int size = _requiredMaxStackSizeFor(handlers->eventHandler(i));
            if (max < size) max = size;
        }
        return max;
    }

    ScriptVM::ScriptVM() : m_eventHandler(NULL), m_parserContext(NULL) {
        m_fnMessage = new CoreVMFunction_message;
        m_fnExit = new CoreVMFunction_exit;
        m_fnWait = new CoreVMFunction_wait(this);
        m_fnAbs = new CoreVMFunction_abs;
        m_fnRandom = new CoreVMFunction_random;
        m_fnNumElements = new CoreVMFunction_num_elements;
        m_fnInc = new CoreVMFunction_inc;
        m_fnDec = new CoreVMFunction_dec;
        m_varRealTimer = new CoreVMDynVar_NKSP_REAL_TIMER;
        m_varPerfTimer = new CoreVMDynVar_NKSP_PERF_TIMER;
        m_fnShLeft = new CoreVMFunction_sh_left;
        m_fnShRight = new CoreVMFunction_sh_right;
        m_fnMin = new CoreVMFunction_min;
        m_fnMax = new CoreVMFunction_max;
    }

    ScriptVM::~ScriptVM() {
        delete m_fnMessage;
        delete m_fnExit;
        delete m_fnWait;
        delete m_fnAbs;
        delete m_fnRandom;
        delete m_fnNumElements;
        delete m_fnInc;
        delete m_fnDec;
        delete m_fnShLeft;
        delete m_fnShRight;
        delete m_fnMin;
        delete m_fnMax;
        delete m_varRealTimer;
        delete m_varPerfTimer;
    }

    VMParserContext* ScriptVM::loadScript(const String& s) {
        std::istringstream iss(s);
        return loadScript(&iss);
    }
    
    VMParserContext* ScriptVM::loadScript(std::istream* is) {
        ParserContext* context = new ParserContext(this);
        //printf("parserCtx=0x%lx\n", (uint64_t)context);

        context->registerBuiltInConstIntVariables( builtInConstIntVariables() );
        context->registerBuiltInIntVariables( builtInIntVariables() );
        context->registerBuiltInIntArrayVariables( builtInIntArrayVariables() );
        context->registerBuiltInDynVariables( builtInDynamicVariables() );

        context->createScanner(is);

        InstrScript_parse(context);
        dmsg(2,("Allocating %ld bytes of global int VM memory.\n", long(context->globalIntVarCount * sizeof(int))));
        dmsg(2,("Allocating %d of global VM string variables.\n", context->globalStrVarCount));
        if (!context->globalIntMemory)
            context->globalIntMemory = new ArrayList<int>();
        if (!context->globalStrMemory)
            context->globalStrMemory = new ArrayList<String>();
        context->globalIntMemory->resize(context->globalIntVarCount);
        memset(&((*context->globalIntMemory)[0]), 0, context->globalIntVarCount * sizeof(int));
        
        context->globalStrMemory->resize(context->globalStrVarCount);

        context->destroyScanner();

        return context;
    }

    void ScriptVM::dumpParsedScript(VMParserContext* context) {
        ParserContext* ctx = dynamic_cast<ParserContext*>(context);
        if (!ctx) {
            std::cerr << "No VM context. So nothing to dump.\n";
            return;
        }
        if (!ctx->handlers) {
            std::cerr << "No event handlers defined in script. So nothing to dump.\n";
            return;
        }
        if (!ctx->globalIntMemory) {
            std::cerr << "Internal error: no global memory assigend to script VM.\n";
            return;
        }
        ctx->handlers->dump();
    }

    VMExecContext* ScriptVM::createExecContext(VMParserContext* parserContext) {
        ParserContext* parserCtx = dynamic_cast<ParserContext*>(parserContext);
        ExecContext* execCtx = new ExecContext();
        
        if (parserCtx->requiredMaxStackSize < 0) {
             parserCtx->requiredMaxStackSize =
                _requiredMaxStackSizeFor(&*parserCtx->handlers);
        }
        execCtx->stack.resize(parserCtx->requiredMaxStackSize);
        dmsg(2,("Created VM exec context with %ld bytes VM stack size.\n",
                long(parserCtx->requiredMaxStackSize * sizeof(ExecContext::StackFrame))));
        //printf("execCtx=0x%lx\n", (uint64_t)execCtx);
        const int polySize = parserCtx->polyphonicIntVarCount;
        execCtx->polyphonicIntMemory.resize(polySize);
        memset(&execCtx->polyphonicIntMemory[0], 0, polySize * sizeof(int));

        dmsg(2,("Allocated %ld bytes polyphonic memory.\n", long(polySize * sizeof(int))));
        return execCtx;
    }

    std::vector<VMSourceToken> ScriptVM::syntaxHighlighting(const String& s) {
        std::istringstream iss(s);
        return syntaxHighlighting(&iss);
    }

    std::vector<VMSourceToken> ScriptVM::syntaxHighlighting(std::istream* is) {
        NkspScanner scanner(is);
        std::vector<SourceToken> tokens = scanner.tokens();
        std::vector<VMSourceToken> result;
        result.resize(tokens.size());
        for (int i = 0; i < tokens.size(); ++i) {
            SourceToken* st = new SourceToken;
            *st = tokens[i];
            result[i] = VMSourceToken(st);
        }
        return result;
    }

    VMFunction* ScriptVM::functionByName(const String& name) {
        if (name == "message") return m_fnMessage;
        else if (name == "exit") return m_fnExit;
        else if (name == "wait") return m_fnWait;
        else if (name == "abs") return m_fnAbs;
        else if (name == "random") return m_fnRandom;
        else if (name == "num_elements") return m_fnNumElements;
        else if (name == "inc") return m_fnInc;
        else if (name == "dec") return m_fnDec;
        else if (name == "sh_left") return m_fnShLeft;
        else if (name == "sh_right") return m_fnShRight;
        else if (name == "min") return m_fnMin;
        else if (name == "max") return m_fnMax;
        return NULL;
    }

    std::map<String,VMIntRelPtr*> ScriptVM::builtInIntVariables() {
        return std::map<String,VMIntRelPtr*>();
    }

    std::map<String,VMInt8Array*> ScriptVM::builtInIntArrayVariables() {
        return std::map<String,VMInt8Array*>();
    }

    std::map<String,VMDynVar*> ScriptVM::builtInDynamicVariables() {
        std::map<String,VMDynVar*> m;

        m["$NKSP_PERF_TIMER"] = m_varPerfTimer;
        m["$NKSP_REAL_TIMER"] = m_varRealTimer;
        m["$KSP_TIMER"] = m_varRealTimer;

        return m;
    }

    std::map<String,int> ScriptVM::builtInConstIntVariables() {
        std::map<String,int> m;

        m["$NI_CB_TYPE_INIT"] = VM_EVENT_HANDLER_INIT;
        m["$NI_CB_TYPE_NOTE"] = VM_EVENT_HANDLER_NOTE;
        m["$NI_CB_TYPE_RELEASE"] = VM_EVENT_HANDLER_RELEASE;
        m["$NI_CB_TYPE_CONTROLLER"] = VM_EVENT_HANDLER_CONTROLLER;

        return m;
    }

    VMEventHandler* ScriptVM::currentVMEventHandler() {
        return m_eventHandler;
    }

    VMParserContext* ScriptVM::currentVMParserContext() {
        return m_parserContext;
    }

    VMExecContext* ScriptVM::currentVMExecContext() {
        if (!m_parserContext) return NULL;
        return m_parserContext->execContext;
    }

    VMExecStatus_t ScriptVM::exec(VMParserContext* parserContext, VMExecContext* execContex, VMEventHandler* handler) {
        m_parserContext = dynamic_cast<ParserContext*>(parserContext);
        if (!m_parserContext) {
            std::cerr << "No VM parser context provided. Did you load a script?.\n";
            return VMExecStatus_t(VM_EXEC_NOT_RUNNING | VM_EXEC_ERROR);
        }

        // a ParserContext object is always tied to exactly one ScriptVM object
        assert(m_parserContext->functionProvider == this);

        ExecContext* ctx = dynamic_cast<ExecContext*>(execContex);
        if (!ctx) {
            std::cerr << "Invalid VM exec context.\n";
            return VMExecStatus_t(VM_EXEC_NOT_RUNNING | VM_EXEC_ERROR);
        }
        EventHandler* h = dynamic_cast<EventHandler*>(handler);
        if (!h) return VM_EXEC_NOT_RUNNING;
        m_eventHandler = handler;

        m_parserContext->execContext = ctx;

        ctx->status = VM_EXEC_RUNNING;
        StmtFlags_t flags = STMT_SUCCESS;

        int& frameIdx = ctx->stackFrame;
        if (frameIdx < 0) { // start condition ...
            frameIdx = -1;
            ctx->pushStack(h);
        }

        while (flags == STMT_SUCCESS && frameIdx >= 0) {
            if (frameIdx >= ctx->stack.size()) { // should never happen, otherwise it's a bug ...
                std::cerr << "CRITICAL: VM stack overflow! (" << frameIdx << ")\n";
                flags = StmtFlags_t(STMT_ABORT_SIGNALLED | STMT_ERROR_OCCURRED);
                break;
            }

            ExecContext::StackFrame& frame = ctx->stack[frameIdx];
            switch (frame.statement->statementType()) {
                case STMT_LEAF: {
                    #if DEBUG_SCRIPTVM_CORE
                    _printIndents(frameIdx);
                    printf("-> STMT_LEAF\n");
                    #endif
                    LeafStatement* leaf = (LeafStatement*) frame.statement;
                    flags = leaf->exec();
                    ctx->popStack();
                    break;
                }

                case STMT_LIST: {
                    #if DEBUG_SCRIPTVM_CORE
                    _printIndents(frameIdx);
                    printf("-> STMT_LIST subidx=%d\n", frame.subindex);
                    #endif
                    Statements* stmts = (Statements*) frame.statement;
                    if (stmts->statement(frame.subindex)) {
                        ctx->pushStack(
                            stmts->statement(frame.subindex++)
                        );
                    } else {
                        #if DEBUG_SCRIPTVM_CORE
                        _printIndents(frameIdx);
                        printf("[END OF LIST] subidx=%d\n", frame.subindex);
                        #endif
                        ctx->popStack();
                    }
                    break;
                }

                case STMT_BRANCH: {
                    #if DEBUG_SCRIPTVM_CORE
                    _printIndents(frameIdx);
                    printf("-> STMT_BRANCH\n");
                    #endif
                    if (frame.subindex < 0) ctx->popStack();
                    else {
                        BranchStatement* branchStmt = (BranchStatement*) frame.statement;
                        frame.subindex = branchStmt->evalBranch();
                        if (frame.subindex >= 0) {
                            ctx->pushStack(
                                branchStmt->branch(frame.subindex)
                            );
                            frame.subindex = -1;
                        } else ctx->popStack();
                    }
                    break;
                }

                case STMT_LOOP: {
                    #if DEBUG_SCRIPTVM_CORE
                    _printIndents(frameIdx);
                    printf("-> STMT_LOOP\n");
                    #endif
                    While* whileStmt = (While*) frame.statement;
                    if (whileStmt->evalLoopStartCondition() && whileStmt->statements()) {
                        ctx->pushStack(
                            whileStmt->statements()
                        );
                    } else ctx->popStack();
                }
            }
        }

        if (flags & STMT_SUSPEND_SIGNALLED) {
            ctx->status = VM_EXEC_SUSPENDED;
        } else {
            ctx->status = VM_EXEC_NOT_RUNNING;
            if (flags & STMT_ERROR_OCCURRED)
                ctx->status = VM_EXEC_ERROR;
            ctx->reset();
        }

        m_eventHandler = NULL;
        m_parserContext->execContext = NULL;
        m_parserContext = NULL;
        return ctx->status;
    }

} // namespace LinuxSampler
1	/*
2	* Copyright (c) 2014 - 2016 Christian Schoenebeck
3	*
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	#include "ScriptVM.h"
11
12	#include <string.h>
13	#include <assert.h>
14	#include "../common/global_private.h"
15	#include "tree.h"
16	#include "CoreVMFunctions.h"
17	#include "CoreVMDynVars.h"
18	#include "editor/NkspScanner.h"
19
20	#define DEBUG_SCRIPTVM_CORE 0
21
22	int InstrScript_parse(LinuxSampler::ParserContext*);
23
24	namespace LinuxSampler {
25
26	static void _printIndents(int n) {
27	for (int i = 0; i < n; ++i) printf(" ");
28	fflush(stdout);
29	}
30
31	static int _requiredMaxStackSizeFor(Statement* statement, int depth = 0) {
32	if (!statement) return 1;
33
34	switch (statement->statementType()) {
35	case STMT_LEAF:
36	#if DEBUG_SCRIPTVM_CORE
37	_printIndents(depth);
38	printf("-> STMT_LEAF\n");
39	#endif
40	return 1;
41
42	case STMT_LIST: {
43	#if DEBUG_SCRIPTVM_CORE
44	_printIndents(depth);
45	printf("-> STMT_LIST\n");
46	#endif
47	Statements* stmts = (Statements*) statement;
48	int max = 0;
49	for (int i = 0; stmts->statement(i); ++i) {
50	int size = _requiredMaxStackSizeFor( stmts->statement(i), depth+1 );
51	if (max < size) max = size;
52	}
53	return max + 1;
54	}
55
56	case STMT_BRANCH: {
57	#if DEBUG_SCRIPTVM_CORE
58	_printIndents(depth);
59	printf("-> STMT_BRANCH\n");
60	#endif
61	BranchStatement* branchStmt = (BranchStatement*) statement;
62	int max = 0;
63	for (int i = 0; branchStmt->branch(i); ++i) {
64	int size = _requiredMaxStackSizeFor( branchStmt->branch(i), depth+1 );
65	if (max < size) max = size;
66	}
67	return max + 1;
68	}
69
70	case STMT_LOOP: {
71	#if DEBUG_SCRIPTVM_CORE
72	_printIndents(depth);
73	printf("-> STMT_LOOP\n");
74	#endif
75	While* whileStmt = (While*) statement;
76	if (whileStmt->statements())
77	return _requiredMaxStackSizeFor( whileStmt->statements() ) + 1;
78	else
79	return 1;
80	}
81	}
82
83	return 1; // actually just to avoid compiler warning
84	}
85
86	static int _requiredMaxStackSizeFor(EventHandlers* handlers) {
87	int max = 1;
88	for (int i = 0; i < handlers->size(); ++i) {
89	int size = _requiredMaxStackSizeFor(handlers->eventHandler(i));
90	if (max < size) max = size;
91	}
92	return max;
93	}
94
95	ScriptVM::ScriptVM() : m_eventHandler(NULL), m_parserContext(NULL) {
96	m_fnMessage = new CoreVMFunction_message;
97	m_fnExit = new CoreVMFunction_exit;
98	m_fnWait = new CoreVMFunction_wait(this);
99	m_fnAbs = new CoreVMFunction_abs;
100	m_fnRandom = new CoreVMFunction_random;
101	m_fnNumElements = new CoreVMFunction_num_elements;
102	m_fnInc = new CoreVMFunction_inc;
103	m_fnDec = new CoreVMFunction_dec;
104	m_varRealTimer = new CoreVMDynVar_NKSP_REAL_TIMER;
105	m_varPerfTimer = new CoreVMDynVar_NKSP_PERF_TIMER;
106	m_fnShLeft = new CoreVMFunction_sh_left;
107	m_fnShRight = new CoreVMFunction_sh_right;
108	m_fnMin = new CoreVMFunction_min;
109	m_fnMax = new CoreVMFunction_max;
110	}
111
112	ScriptVM::~ScriptVM() {
113	delete m_fnMessage;
114	delete m_fnExit;
115	delete m_fnWait;
116	delete m_fnAbs;
117	delete m_fnRandom;
118	delete m_fnNumElements;
119	delete m_fnInc;
120	delete m_fnDec;
121	delete m_fnShLeft;
122	delete m_fnShRight;
123	delete m_fnMin;
124	delete m_fnMax;
125	delete m_varRealTimer;
126	delete m_varPerfTimer;
127	}
128
129	VMParserContext* ScriptVM::loadScript(const String& s) {
130	std::istringstream iss(s);
131	return loadScript(&iss);
132	}
133
134	VMParserContext* ScriptVM::loadScript(std::istream* is) {
135	ParserContext* context = new ParserContext(this);
136	//printf("parserCtx=0x%lx\n", (uint64_t)context);
137
138	context->registerBuiltInConstIntVariables( builtInConstIntVariables() );
139	context->registerBuiltInIntVariables( builtInIntVariables() );
140	context->registerBuiltInIntArrayVariables( builtInIntArrayVariables() );
141	context->registerBuiltInDynVariables( builtInDynamicVariables() );
142
143	context->createScanner(is);
144
145	InstrScript_parse(context);
146	dmsg(2,("Allocating %ld bytes of global int VM memory.\n", long(context->globalIntVarCount * sizeof(int))));
147	dmsg(2,("Allocating %d of global VM string variables.\n", context->globalStrVarCount));
148	if (!context->globalIntMemory)
149	context->globalIntMemory = new ArrayList<int>();
150	if (!context->globalStrMemory)
151	context->globalStrMemory = new ArrayList<String>();
152	context->globalIntMemory->resize(context->globalIntVarCount);
153	memset(&((context->globalIntMemory)[0]), 0, context->globalIntVarCount sizeof(int));
154
155	context->globalStrMemory->resize(context->globalStrVarCount);
156
157	context->destroyScanner();
158
159	return context;
160	}
161
162	void ScriptVM::dumpParsedScript(VMParserContext* context) {
163	ParserContext* ctx = dynamic_cast<ParserContext*>(context);
164	if (!ctx) {
165	std::cerr << "No VM context. So nothing to dump.\n";
166	return;
167	}
168	if (!ctx->handlers) {
169	std::cerr << "No event handlers defined in script. So nothing to dump.\n";
170	return;
171	}
172	if (!ctx->globalIntMemory) {
173	std::cerr << "Internal error: no global memory assigend to script VM.\n";
174	return;
175	}
176	ctx->handlers->dump();
177	}
178
179	VMExecContext* ScriptVM::createExecContext(VMParserContext* parserContext) {
180	ParserContext* parserCtx = dynamic_cast<ParserContext*>(parserContext);
181	ExecContext* execCtx = new ExecContext();
182
183	if (parserCtx->requiredMaxStackSize < 0) {
184	parserCtx->requiredMaxStackSize =
185	_requiredMaxStackSizeFor(&*parserCtx->handlers);
186	}
187	execCtx->stack.resize(parserCtx->requiredMaxStackSize);
188	dmsg(2,("Created VM exec context with %ld bytes VM stack size.\n",
189	long(parserCtx->requiredMaxStackSize * sizeof(ExecContext::StackFrame))));
190	//printf("execCtx=0x%lx\n", (uint64_t)execCtx);
191	const int polySize = parserCtx->polyphonicIntVarCount;
192	execCtx->polyphonicIntMemory.resize(polySize);
193	memset(&execCtx->polyphonicIntMemory[0], 0, polySize * sizeof(int));
194
195	dmsg(2,("Allocated %ld bytes polyphonic memory.\n", long(polySize * sizeof(int))));
196	return execCtx;
197	}
198
199	std::vector<VMSourceToken> ScriptVM::syntaxHighlighting(const String& s) {
200	std::istringstream iss(s);
201	return syntaxHighlighting(&iss);
202	}
203
204	std::vector<VMSourceToken> ScriptVM::syntaxHighlighting(std::istream* is) {
205	NkspScanner scanner(is);
206	std::vector<SourceToken> tokens = scanner.tokens();
207	std::vector<VMSourceToken> result;
208	result.resize(tokens.size());
209	for (int i = 0; i < tokens.size(); ++i) {
210	SourceToken* st = new SourceToken;
211	*st = tokens[i];
212	result[i] = VMSourceToken(st);
213	}
214	return result;
215	}
216
217	VMFunction* ScriptVM::functionByName(const String& name) {
218	if (name == "message") return m_fnMessage;
219	else if (name == "exit") return m_fnExit;
220	else if (name == "wait") return m_fnWait;
221	else if (name == "abs") return m_fnAbs;
222	else if (name == "random") return m_fnRandom;
223	else if (name == "num_elements") return m_fnNumElements;
224	else if (name == "inc") return m_fnInc;
225	else if (name == "dec") return m_fnDec;
226	else if (name == "sh_left") return m_fnShLeft;
227	else if (name == "sh_right") return m_fnShRight;
228	else if (name == "min") return m_fnMin;
229	else if (name == "max") return m_fnMax;
230	return NULL;
231	}
232
233	std::map<String,VMIntRelPtr*> ScriptVM::builtInIntVariables() {
234	return std::map<String,VMIntRelPtr*>();
235	}
236
237	std::map<String,VMInt8Array*> ScriptVM::builtInIntArrayVariables() {
238	return std::map<String,VMInt8Array*>();
239	}
240
241	std::map<String,VMDynVar*> ScriptVM::builtInDynamicVariables() {
242	std::map<String,VMDynVar*> m;
243
244	m["$NKSP_PERF_TIMER"] = m_varPerfTimer;
245	m["$NKSP_REAL_TIMER"] = m_varRealTimer;
246	m["$KSP_TIMER"] = m_varRealTimer;
247
248	return m;
249	}
250
251	std::map<String,int> ScriptVM::builtInConstIntVariables() {
252	std::map<String,int> m;
253
254	m["$NI_CB_TYPE_INIT"] = VM_EVENT_HANDLER_INIT;
255	m["$NI_CB_TYPE_NOTE"] = VM_EVENT_HANDLER_NOTE;
256	m["$NI_CB_TYPE_RELEASE"] = VM_EVENT_HANDLER_RELEASE;
257	m["$NI_CB_TYPE_CONTROLLER"] = VM_EVENT_HANDLER_CONTROLLER;
258
259	return m;
260	}
261
262	VMEventHandler* ScriptVM::currentVMEventHandler() {
263	return m_eventHandler;
264	}
265
266	VMParserContext* ScriptVM::currentVMParserContext() {
267	return m_parserContext;
268	}
269
270	VMExecContext* ScriptVM::currentVMExecContext() {
271	if (!m_parserContext) return NULL;
272	return m_parserContext->execContext;
273	}
274
275	VMExecStatus_t ScriptVM::exec(VMParserContext* parserContext, VMExecContext* execContex, VMEventHandler* handler) {
276	m_parserContext = dynamic_cast<ParserContext*>(parserContext);
277	if (!m_parserContext) {
278	std::cerr << "No VM parser context provided. Did you load a script?.\n";
279	return VMExecStatus_t(VM_EXEC_NOT_RUNNING \| VM_EXEC_ERROR);
280	}
281
282	// a ParserContext object is always tied to exactly one ScriptVM object
283	assert(m_parserContext->functionProvider == this);
284
285	ExecContext* ctx = dynamic_cast<ExecContext*>(execContex);
286	if (!ctx) {
287	std::cerr << "Invalid VM exec context.\n";
288	return VMExecStatus_t(VM_EXEC_NOT_RUNNING \| VM_EXEC_ERROR);
289	}
290	EventHandler* h = dynamic_cast<EventHandler*>(handler);
291	if (!h) return VM_EXEC_NOT_RUNNING;
292	m_eventHandler = handler;
293
294	m_parserContext->execContext = ctx;
295
296	ctx->status = VM_EXEC_RUNNING;
297	StmtFlags_t flags = STMT_SUCCESS;
298
299	int& frameIdx = ctx->stackFrame;
300	if (frameIdx < 0) { // start condition ...
301	frameIdx = -1;
302	ctx->pushStack(h);
303	}
304
305	while (flags == STMT_SUCCESS && frameIdx >= 0) {
306	if (frameIdx >= ctx->stack.size()) { // should never happen, otherwise it's a bug ...
307	std::cerr << "CRITICAL: VM stack overflow! (" << frameIdx << ")\n";
308	flags = StmtFlags_t(STMT_ABORT_SIGNALLED \| STMT_ERROR_OCCURRED);
309	break;
310	}
311
312	ExecContext::StackFrame& frame = ctx->stack[frameIdx];
313	switch (frame.statement->statementType()) {
314	case STMT_LEAF: {
315	#if DEBUG_SCRIPTVM_CORE
316	_printIndents(frameIdx);
317	printf("-> STMT_LEAF\n");
318	#endif
319	LeafStatement* leaf = (LeafStatement*) frame.statement;
320	flags = leaf->exec();
321	ctx->popStack();
322	break;
323	}
324
325	case STMT_LIST: {
326	#if DEBUG_SCRIPTVM_CORE
327	_printIndents(frameIdx);
328	printf("-> STMT_LIST subidx=%d\n", frame.subindex);
329	#endif
330	Statements* stmts = (Statements*) frame.statement;
331	if (stmts->statement(frame.subindex)) {
332	ctx->pushStack(
333	stmts->statement(frame.subindex++)
334	);
335	} else {
336	#if DEBUG_SCRIPTVM_CORE
337	_printIndents(frameIdx);
338	printf("[END OF LIST] subidx=%d\n", frame.subindex);
339	#endif
340	ctx->popStack();
341	}
342	break;
343	}
344
345	case STMT_BRANCH: {
346	#if DEBUG_SCRIPTVM_CORE
347	_printIndents(frameIdx);
348	printf("-> STMT_BRANCH\n");
349	#endif
350	if (frame.subindex < 0) ctx->popStack();
351	else {
352	BranchStatement* branchStmt = (BranchStatement*) frame.statement;
353	frame.subindex = branchStmt->evalBranch();
354	if (frame.subindex >= 0) {
355	ctx->pushStack(
356	branchStmt->branch(frame.subindex)
357	);
358	frame.subindex = -1;
359	} else ctx->popStack();
360	}
361	break;
362	}
363
364	case STMT_LOOP: {
365	#if DEBUG_SCRIPTVM_CORE
366	_printIndents(frameIdx);
367	printf("-> STMT_LOOP\n");
368	#endif
369	While* whileStmt = (While*) frame.statement;
370	if (whileStmt->evalLoopStartCondition() && whileStmt->statements()) {
371	ctx->pushStack(
372	whileStmt->statements()
373	);
374	} else ctx->popStack();
375	}
376	}
377	}
378
379	if (flags & STMT_SUSPEND_SIGNALLED) {
380	ctx->status = VM_EXEC_SUSPENDED;
381	} else {
382	ctx->status = VM_EXEC_NOT_RUNNING;
383	if (flags & STMT_ERROR_OCCURRED)
384	ctx->status = VM_EXEC_ERROR;
385	ctx->reset();
386	}
387
388	m_eventHandler = NULL;
389	m_parserContext->execContext = NULL;
390	m_parserContext = NULL;
391	return ctx->status;
392	}
393
394	} // namespace LinuxSampler