Live Variables Unable to Start

[codex653]

I am trying to get up and running with live variables on the embedded version of gdb (5.2R9) and continually keep getting this error:

VisualGDB version: 5.2.15.1452
—————— System.Exception ——————
System.Exception: Cannot evaluate ‘&(echo)’: -var-create: unable to create variable object
at e51.e3(String b, Boolean a)
at e51.t2(String a)
at zd.AddLiveVariableCmd.<>c__DisplayClass3_0.<Execute>b__0(e51 w)

I’ve been unable to find anything useful on the forums or elsewhere on the internet so far. Any ideas on how to get me up and running?

 

[support]

Hi,

It looks like you are trying to create a live variable for an expression that is not valid in the current context. Is it a global variable visible from all the source files or a local variable inside a function/method?

[codex653]

It’s just a local variable inside of my primary .cpp file that has the main(void) function. This variable, shown below as “flag”, is only accessed by the main  function and a callback function from TIM2_IRQHandler().

 

/*****************UartTesting.cpp************************/

#include <stm32f7xx_hal.h>
#include “core.h”
#include “definitions.h”
#include “gpio.h”
#include “uart.h”
#include “event.h”

/****************

*Some setup code went here

****************/

//Variable I am trying to watch live
volatile bool flag = false;

int main(void)
{
HAL_Init();
SystemClockConfig();

/****************

*Place holder for  non-important code here…

****************/
for (;;)
{
if (flag)
//Do a thing
}
}

void testCallback()
{
testPin.toggle();
ledPin_Blue.toggle();
flag = true;
}

void TIM2_IRQHandler()
{
uint32_t isrflags = READ_REG(TIM2->SR);
isrflags &= ~(1 << 1u);

testCallback();

WRITE_REG(TIM2->SR, isrflags);
HAL_NVIC_DisableIRQ(TIM2_IRQn);
}

[support]

Hi,

This should normally work. Please try adding the variable manually by typing “flag” in the Live Variables window instead of using the right-click. If you still get the “echo” error, please try renaming the variable to something unique. As VisualGDB always expands the preprocessor macros in the Live Variables, it could accidentally expand a macro with the same name that would resolve to an invalid name like “echo”.

[codex653]

Manually adding it worked. In the past when I’ve tried to manually add the variable it did not work, so I’m a tad perplexed. Oh well. It works now and that’s all that matters!

[support]

Hi,

Good to know it works. If you ever decide to diagnose this, let us know and we will help you understand why right-click adding does not work.

[Author]

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