Scope of the variable can be reduced

[Simone Gasparella]

Hi forum ,

I am using cppcheck 2.6 i an embedded c project .
The software is showing the style issue : "the scope of the variable can be reduced"...
It is showing this message in some variables before a switch ..
If i try to move some variables inside the cases for solving the style issue I get an error from the compiler..
How Can I fix it ?

Thanks for the suggestion

[CHR]

Hard to say from the snippets you posted, code as text would be better. Maybe you need to open a new scope for a casestatement?

...
case FOO: {
    uint8_t modbus = ...
}
...

[Simone Gasparella]

Hi CHR..
Thanks for your answer
if i try to do it I get :
a label can only be part of a statement and a declaration is not a statement

[Daniel Marjamäki]

In an embedded c code it is usual to have all variables at the start of a function. Feel free to keep that programming style. Then you can just suppress these warnings --suppress=variableScope.

a label can only be part of a statement and a declaration is not a statement

Sounds strange!

What happens if you move the variable declaration into the if.

if( uart_Crc16_In(COM_INV) == 0)
{
    uint16_t modbus_register_data_read = 0;

[Jean-Loic MARTIN]

Hi Simone,

A workaround is too put a ';' after the ':'

case FOO:; 
    uint8_t modbus = ...

No need to put braces.

[Simone Gasparella]

Hi ..

I am using cpp check..

Can you tell me the place where I can ask help for finding this issue ?

static uint64_t CalK(machine_status *machine, uint16_t chn, uint32_t adc)
{
uint16_t i, n;
int32_t k1, k2, k;

n = K_SENSE_POINTS_NUM;
for (i=0; i!=n; i++) {
if (adc <= machine->uc1_output[chn].ksense.adc[i]) {
break;
}
}
if (i == 0) {
return machine->uc1_output[chn].ksense.k[0];
}
if (i == n) {
return machine->uc1_output[chn].ksense.k[n-1];
}
k1 = machine->uc1_output[chn].ksense.k[i-1];
k2 = machine->uc1_output[chn].ksense.k[i];

k = k1 + ((k2-k1)*((int32_t)(adc-machine->uc1_output[chn].ksense.adc[i-1])))/((int32_t)(machine->uc1_output[chn].ksense.adc[i] - machine->uc1_output[chn].ksense.adc[i-1]));

return k;
}

I don't understand if cpp check is able to detect the possible divion by 0 if k2 = k1 for example .. or if machine->uc1_output[chn].ksense.adc[i] = machine->uc1_output[chn].ksense.adc[i-1]));

Is cpp check able to detect this possible issue ?

Thanks a lot for your support

--
Simone Gasparella | Software Engineering Manager

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