rexx-things/modules/api/c++/call.example/runRexxProgram.cpp
2025-03-12 20:50:48 +00:00

234 lines
9.2 KiB
C++

/*----------------------------------------------------------------------------*/
/* */
/* Copyright (c) 2008-2017 Rexx Language Association. All rights reserved. */
/* */
/* This program and the accompanying materials are made available under */
/* the terms of the Common Public License v1.0 which accompanies this */
/* distribution. A copy is also available at the following address: */
/* https://www.oorexx.org/license.html */
/* */
/* Redistribution and use in source and binary forms, with or */
/* without modification, are permitted provided that the following */
/* conditions are met: */
/* */
/* Redistributions of source code must retain the above copyright */
/* notice, this list of conditions and the following disclaimer. */
/* Redistributions in binary form must reproduce the above copyright */
/* notice, this list of conditions and the following disclaimer in */
/* the documentation and/or other materials provided with the distribution. */
/* */
/* Neither the name of Rexx Language Association nor the names */
/* of its contributors may be used to endorse or promote products */
/* derived from this software without specific prior written permission. */
/* */
/* THIS SOFTWARE IS PROVIDED BY THE COPYright HOLDERS AND CONTRIBUTORS */
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/* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS */
/* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
/* */
/*----------------------------------------------------------------------------*/
/**
* A simple example that creates an instance of the interpreter and uses that
* instance to execute a Rexx program. The program name must be passed in the
* command line. For example:
*
* runRexxProgram HelloWorld.rex
* runRexxProgram backward.fnc
* runRexxProgram tooRecursiveTrapped.rex
* runRexxProgram tooRecursiveUnhandled.rex
*
* backward.fnc demonstrates how to pass arguments into the called program.
*/
#include "oorexxapi.h"
#include <stdio.h>
#include <string.h>
#if defined(_WIN32)
#define _CDECL __cdecl
#else
#define _CDECL
#endif
/* Prototypes for several simple helper functions that demonstrate usage of some
* of the native C++ APIs. The functions themselves are at the bottom of the
* file.
*/
bool checkForCondition(RexxThreadContext *c, bool clear);
void printInterpreterVersion(RexxInstance *);
int _CDECL main(int argc, char **argv)
{
char *programName = NULL;
if ( argc == 2 )
{
programName = argv[1];
}
if ( programName == NULL || *programName == '\0' )
{
printf("You must pass in the name of a Rexx program on the command line.\n");
printf(" For example: %s crash.rex.\n", argv[0]);
return 9;
}
// These are the arguments to RexxCreateInterpreter(). An array of any
// number of Rexx options can be passed in, but for this example we do not
// need any options. So, we use NULL.
RexxInstance *interpreter;
RexxThreadContext *threadContext;
RexxOption *options = NULL;
if ( RexxCreateInterpreter(&interpreter, &threadContext, options) == 0 )
{
printf("Failed to create interpreter, aborting.\n");
exit(1);
}
printInterpreterVersion(interpreter);
// If we want to pass arguments to the program we need to put them into an
// array of Rexx objects. We can pass null if there are no arguments.
RexxArrayObject args = NULL;
if ( strcmp("backward.fnc", programName) == 0 )
{
RexxStringObject str = threadContext->String("These words will be swapped");
args = threadContext->ArrayOfOne(str);
}
// Execute the program and get the result returned to us.
printf("Using interpreter to execute %s\n\n", programName);
RexxObjectPtr result = threadContext->CallProgram(programName, args);
// During the program execution, a condition can be raised if there is an
// unexpected error. If an exception occurred and is pending,
// CheckCondtion() will return true. In this case we print out some
// information on the condition, otherwise we print out the return, if any,
// from the program.
if (threadContext->CheckCondition())
{
checkForCondition(threadContext, true);
}
else if (result != NULLOBJECT)
{
// Note that we use ObjectToStringValue(). That is guarenteed to return
// the ASCII-Z string representation of the object. If we passed in, say
// an .array object to the CString() function, we would get a crash.
printf("\nProgram result=%s\n\n", threadContext->ObjectToStringValue(result));
}
// Now wait for the interpreter to terminate and we are done.
interpreter->Terminate();
return 0;
}
/**
* Below are several helper functions that demonstrate how to use some of the
* different C++ native APIs.
*/
/**
* Given an interpreter instance, prints out the interpreter version and
* language version. The documentation in the ooRexx programming guide explains
* the byte encoding of the version numbers.
*/
void printInterpreterVersion(RexxInstance *interpreter)
{
wholenumber_t ver = interpreter->InterpreterVersion();
wholenumber_t lang = interpreter->LanguageLevel();
printf("Created interpreter instance version=%zd.%zd.%zd language level=%zd.%02zd\n\n",
(ver & 0xff0000) >> 16, (ver & 0x00ff00) >> 8, ver & 0x0000ff, (lang & 0xff00) >> 8, lang & 0x00ff);
}
/**
* Given a condition object, extracts and returns as a whole number the subcode
* of the condition.
*/
inline wholenumber_t conditionSubCode(RexxCondition *condition)
{
return (condition->code - (condition->rc * 1000));
}
/**
* Outputs the typical condition message. For example:
*
* 4 *-* say dt~number
* Error 97 running C:\work\qTest.rex line 4: Object method not found
* Error 97.1: Object "a DateTime" does not understand message "NUMBER"
*
* @param c The thread context we are operating in.
* @param condObj The condition information object. The object returned from
* the C++ API GetConditionInfo()
* @param condition The RexxCondition struct. The filled in struct from the
* C++ API DecodeConditionInfo().
*
* @assumes There is a condition and that condObj and condition are valid.
*/
void standardConditionMsg(RexxThreadContext *c, RexxDirectoryObject condObj, RexxCondition *condition)
{
RexxObjectPtr list = c->SendMessage0(condObj, "TRACEBACK");
if ( list != NULLOBJECT )
{
RexxArrayObject a = (RexxArrayObject)c->SendMessage0(list, "ALLITEMS");
if ( a != NULLOBJECT )
{
size_t count = c->ArrayItems(a);
for ( size_t i = 1; i <= count; i++ )
{
RexxObjectPtr o = c->ArrayAt(a, i);
if ( o != NULLOBJECT )
{
printf("%s\n", c->ObjectToStringValue(o));
}
}
}
}
printf("Error %zd running %s line %zd: %s\n", condition->rc, c->CString(condition->program),
condition->position, c->CString(condition->errortext));
printf("Error %zd.%03zd: %s\n", condition->rc, conditionSubCode(condition), c->CString(condition->message));
}
/**
* Given a thread context, checks for a raised condition, and prints out the
* standard condition message if there is a condition.
*
* @param c Thread context we are operating in.
* @param clear Whether to clear the condition or not.
*
* @return True if there was a condition, otherwise false.
*/
bool checkForCondition(RexxThreadContext *c, bool clear)
{
if ( c->CheckCondition() )
{
RexxCondition condition;
RexxDirectoryObject condObj = c->GetConditionInfo();
if ( condObj != NULLOBJECT )
{
c->DecodeConditionInfo(condObj, &condition);
standardConditionMsg(c, condObj, &condition);
if ( clear )
{
c->ClearCondition();
}
return true;
}
}
return false;
}