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_varRealTimer = new CoreVMDynVar_NKSP_REAL_TIMER;
        m_varPerfTimer = new CoreVMDynVar_NKSP_PERF_TIMER;
    }

    ScriptVM::~ScriptVM() {
        delete m_fnMessage;
        delete m_fnExit;
        delete m_fnWait;
        delete m_fnAbs;
        delete m_fnRandom;
        delete m_fnNumElements;
        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;
        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() {
        return std::map<String,int>();
    }

    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	schoenebeck	2581	/*
2	schoenebeck	2879	* 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			#include "ScriptVM.h"
11
12	schoenebeck	2588	#include <string.h>
13	schoenebeck	2619	#include <assert.h>
14	schoenebeck	2581	#include "../common/global_private.h"
15			#include "tree.h"
16	schoenebeck	2885	#include "CoreVMFunctions.h"
17	schoenebeck	2942	#include "CoreVMDynVars.h"
18	schoenebeck	2885	#include "editor/NkspScanner.h"
19	schoenebeck	2581
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	schoenebeck	2885	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	schoenebeck	2942	m_varRealTimer = new CoreVMDynVar_NKSP_REAL_TIMER;
103			m_varPerfTimer = new CoreVMDynVar_NKSP_PERF_TIMER;
104	schoenebeck	2581	}
105
106			ScriptVM::~ScriptVM() {
107	schoenebeck	2885	delete m_fnMessage;
108			delete m_fnExit;
109			delete m_fnWait;
110			delete m_fnAbs;
111			delete m_fnRandom;
112			delete m_fnNumElements;
113	schoenebeck	2942	delete m_varRealTimer;
114			delete m_varPerfTimer;
115	schoenebeck	2581	}
116
117	schoenebeck	2588	VMParserContext* ScriptVM::loadScript(const String& s) {
118	schoenebeck	2581	std::istringstream iss(s);
119	schoenebeck	2588	return loadScript(&iss);
120	schoenebeck	2581	}
121
122	schoenebeck	2588	VMParserContext* ScriptVM::loadScript(std::istream* is) {
123			ParserContext* context = new ParserContext(this);
124			//printf("parserCtx=0x%lx\n", (uint64_t)context);
125	schoenebeck	2594
126			context->registerBuiltInConstIntVariables( builtInConstIntVariables() );
127			context->registerBuiltInIntVariables( builtInIntVariables() );
128			context->registerBuiltInIntArrayVariables( builtInIntArrayVariables() );
129	schoenebeck	2942	context->registerBuiltInDynVariables( builtInDynamicVariables() );
130	schoenebeck	2594
131	schoenebeck	2588	context->createScanner(is);
132	schoenebeck	2581
133	schoenebeck	2588	InstrScript_parse(context);
134	persson	2837	dmsg(2,("Allocating %ld bytes of global int VM memory.\n", long(context->globalIntVarCount * sizeof(int))));
135	schoenebeck	2611	dmsg(2,("Allocating %d of global VM string variables.\n", context->globalStrVarCount));
136	schoenebeck	2588	if (!context->globalIntMemory)
137			context->globalIntMemory = new ArrayList<int>();
138			if (!context->globalStrMemory)
139			context->globalStrMemory = new ArrayList<String>();
140			context->globalIntMemory->resize(context->globalIntVarCount);
141			memset(&((context->globalIntMemory)[0]), 0, context->globalIntVarCount sizeof(int));
142
143			context->globalStrMemory->resize(context->globalStrVarCount);
144	schoenebeck	2581
145	schoenebeck	2588	context->destroyScanner();
146	schoenebeck	2581
147	schoenebeck	2588	return context;
148	schoenebeck	2581	}
149
150	schoenebeck	2588	void ScriptVM::dumpParsedScript(VMParserContext* context) {
151			ParserContext* ctx = dynamic_cast<ParserContext*>(context);
152			if (!ctx) {
153	schoenebeck	2581	std::cerr << "No VM context. So nothing to dump.\n";
154			return;
155			}
156	schoenebeck	2588	if (!ctx->handlers) {
157	schoenebeck	2581	std::cerr << "No event handlers defined in script. So nothing to dump.\n";
158			return;
159			}
160	schoenebeck	2588	if (!ctx->globalIntMemory) {
161	schoenebeck	2581	std::cerr << "Internal error: no global memory assigend to script VM.\n";
162			return;
163			}
164	schoenebeck	2588	ctx->handlers->dump();
165	schoenebeck	2581	}
166
167	schoenebeck	2588	VMExecContext* ScriptVM::createExecContext(VMParserContext* parserContext) {
168			ParserContext* parserCtx = dynamic_cast<ParserContext*>(parserContext);
169			ExecContext* execCtx = new ExecContext();
170
171			if (parserCtx->requiredMaxStackSize < 0) {
172			parserCtx->requiredMaxStackSize =
173			_requiredMaxStackSizeFor(&*parserCtx->handlers);
174			}
175			execCtx->stack.resize(parserCtx->requiredMaxStackSize);
176	persson	2837	dmsg(2,("Created VM exec context with %ld bytes VM stack size.\n",
177			long(parserCtx->requiredMaxStackSize * sizeof(ExecContext::StackFrame))));
178	schoenebeck	2588	//printf("execCtx=0x%lx\n", (uint64_t)execCtx);
179			const int polySize = parserCtx->polyphonicIntVarCount;
180			execCtx->polyphonicIntMemory.resize(polySize);
181			memset(&execCtx->polyphonicIntMemory[0], 0, polySize * sizeof(int));
182
183	persson	2837	dmsg(2,("Allocated %ld bytes polyphonic memory.\n", long(polySize * sizeof(int))));
184	schoenebeck	2588	return execCtx;
185	schoenebeck	2581	}
186
187	schoenebeck	2885	std::vector<VMSourceToken> ScriptVM::syntaxHighlighting(const String& s) {
188			std::istringstream iss(s);
189			return syntaxHighlighting(&iss);
190			}
191
192			std::vector<VMSourceToken> ScriptVM::syntaxHighlighting(std::istream* is) {
193			NkspScanner scanner(is);
194			std::vector<SourceToken> tokens = scanner.tokens();
195			std::vector<VMSourceToken> result;
196			result.resize(tokens.size());
197			for (int i = 0; i < tokens.size(); ++i) {
198			SourceToken* st = new SourceToken;
199			*st = tokens[i];
200			result[i] = VMSourceToken(st);
201			}
202			return result;
203			}
204
205	schoenebeck	2581	VMFunction* ScriptVM::functionByName(const String& name) {
206	schoenebeck	2885	if (name == "message") return m_fnMessage;
207			else if (name == "exit") return m_fnExit;
208			else if (name == "wait") return m_fnWait;
209			else if (name == "abs") return m_fnAbs;
210			else if (name == "random") return m_fnRandom;
211			else if (name == "num_elements") return m_fnNumElements;
212	schoenebeck	2581	return NULL;
213			}
214	schoenebeck	2588
215	schoenebeck	2594	std::map<String,VMIntRelPtr*> ScriptVM::builtInIntVariables() {
216			return std::map<String,VMIntRelPtr*>();
217			}
218
219			std::map<String,VMInt8Array*> ScriptVM::builtInIntArrayVariables() {
220			return std::map<String,VMInt8Array*>();
221			}
222
223	schoenebeck	2942	std::map<String,VMDynVar*> ScriptVM::builtInDynamicVariables() {
224			std::map<String,VMDynVar*> m;
225
226			m["$NKSP_PERF_TIMER"] = m_varPerfTimer;
227			m["$NKSP_REAL_TIMER"] = m_varRealTimer;
228			m["$KSP_TIMER"] = m_varRealTimer;
229
230			return m;
231			}
232
233	schoenebeck	2594	std::map<String,int> ScriptVM::builtInConstIntVariables() {
234			return std::map<String,int>();
235			}
236
237	schoenebeck	2879	VMEventHandler* ScriptVM::currentVMEventHandler() {
238			return m_eventHandler;
239			}
240
241	schoenebeck	2588	VMParserContext* ScriptVM::currentVMParserContext() {
242			return m_parserContext;
243			}
244
245	schoenebeck	2581	VMExecContext* ScriptVM::currentVMExecContext() {
246	schoenebeck	2588	if (!m_parserContext) return NULL;
247			return m_parserContext->execContext;
248	schoenebeck	2581	}
249
250	schoenebeck	2588	VMExecStatus_t ScriptVM::exec(VMParserContext* parserContext, VMExecContext* execContex, VMEventHandler* handler) {
251			m_parserContext = dynamic_cast<ParserContext*>(parserContext);
252			if (!m_parserContext) {
253			std::cerr << "No VM parser context provided. Did you load a script?.\n";
254	schoenebeck	2581	return VMExecStatus_t(VM_EXEC_NOT_RUNNING \| VM_EXEC_ERROR);
255			}
256
257	schoenebeck	2611	// a ParserContext object is always tied to exactly one ScriptVM object
258			assert(m_parserContext->functionProvider == this);
259
260	schoenebeck	2581	ExecContext* ctx = dynamic_cast<ExecContext*>(execContex);
261			if (!ctx) {
262			std::cerr << "Invalid VM exec context.\n";
263			return VMExecStatus_t(VM_EXEC_NOT_RUNNING \| VM_EXEC_ERROR);
264			}
265			EventHandler* h = dynamic_cast<EventHandler*>(handler);
266			if (!h) return VM_EXEC_NOT_RUNNING;
267	schoenebeck	2879	m_eventHandler = handler;
268	schoenebeck	2581
269	schoenebeck	2588	m_parserContext->execContext = ctx;
270	schoenebeck	2581
271			ctx->status = VM_EXEC_RUNNING;
272			StmtFlags_t flags = STMT_SUCCESS;
273
274			int& frameIdx = ctx->stackFrame;
275			if (frameIdx < 0) { // start condition ...
276			frameIdx = -1;
277			ctx->pushStack(h);
278			}
279
280			while (flags == STMT_SUCCESS && frameIdx >= 0) {
281			if (frameIdx >= ctx->stack.size()) { // should never happen, otherwise it's a bug ...
282			std::cerr << "CRITICAL: VM stack overflow! (" << frameIdx << ")\n";
283			flags = StmtFlags_t(STMT_ABORT_SIGNALLED \| STMT_ERROR_OCCURRED);
284			break;
285			}
286
287			ExecContext::StackFrame& frame = ctx->stack[frameIdx];
288			switch (frame.statement->statementType()) {
289			case STMT_LEAF: {
290			#if DEBUG_SCRIPTVM_CORE
291			_printIndents(frameIdx);
292			printf("-> STMT_LEAF\n");
293			#endif
294			LeafStatement* leaf = (LeafStatement*) frame.statement;
295			flags = leaf->exec();
296			ctx->popStack();
297			break;
298			}
299
300			case STMT_LIST: {
301			#if DEBUG_SCRIPTVM_CORE
302			_printIndents(frameIdx);
303			printf("-> STMT_LIST subidx=%d\n", frame.subindex);
304			#endif
305			Statements* stmts = (Statements*) frame.statement;
306			if (stmts->statement(frame.subindex)) {
307			ctx->pushStack(
308			stmts->statement(frame.subindex++)
309			);
310			} else {
311			#if DEBUG_SCRIPTVM_CORE
312			_printIndents(frameIdx);
313			printf("[END OF LIST] subidx=%d\n", frame.subindex);
314			#endif
315			ctx->popStack();
316			}
317			break;
318			}
319
320			case STMT_BRANCH: {
321			#if DEBUG_SCRIPTVM_CORE
322			_printIndents(frameIdx);
323			printf("-> STMT_BRANCH\n");
324			#endif
325			if (frame.subindex < 0) ctx->popStack();
326			else {
327			BranchStatement* branchStmt = (BranchStatement*) frame.statement;
328			frame.subindex = branchStmt->evalBranch();
329			if (frame.subindex >= 0) {
330			ctx->pushStack(
331			branchStmt->branch(frame.subindex)
332			);
333			frame.subindex = -1;
334			} else ctx->popStack();
335			}
336			break;
337			}
338
339			case STMT_LOOP: {
340			#if DEBUG_SCRIPTVM_CORE
341			_printIndents(frameIdx);
342			printf("-> STMT_LOOP\n");
343			#endif
344			While* whileStmt = (While*) frame.statement;
345			if (whileStmt->evalLoopStartCondition() && whileStmt->statements()) {
346			ctx->pushStack(
347			whileStmt->statements()
348			);
349			} else ctx->popStack();
350			}
351			}
352			}
353
354			if (flags & STMT_SUSPEND_SIGNALLED) {
355			ctx->status = VM_EXEC_SUSPENDED;
356			} else {
357			ctx->status = VM_EXEC_NOT_RUNNING;
358			if (flags & STMT_ERROR_OCCURRED)
359			ctx->status = VM_EXEC_ERROR;
360			ctx->reset();
361			}
362
363	schoenebeck	2879	m_eventHandler = NULL;
364	schoenebeck	2588	m_parserContext->execContext = NULL;
365			m_parserContext = NULL;
366	schoenebeck	2581	return ctx->status;
367			}
368
369			} // namespace LinuxSampler