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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?
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?
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);
}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”.
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!
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