Declaring a variable inside a for loop; getting error with c2000 compiler

Question

I am working on a C project for a TI TMS320x DSP with the C2000 compiler. I tried to initialized a loop variable directly inside a for loop, but somehow I get a compiler error:

Code:

for (int TabCnt = 0; TabCnt < 10; TabCnt++)
{
    x++;
}

Error:

error #20: identifier "TabCnt" is undefined

I figure this might be a wrong compiler setting? If I declare the variable outside of the loop, it works perfectly.

Possible duplicate of [C: for loop int initial declaration](https://stackoverflow.com/questions/1287863/c-for-loop-int-initial-declaration) — Evan Carroll, Jul 24 '18 at 19:23

score 4 · Accepted Answer · edited Jan 09 '19 at 09:16

4

That's because you are using a compiler that supports only C89.

This syntax:

for (int TabCnt = 0; TabCnt < 10; TabCnt++)

is only valid since C99. The solution is either enable C99 if supported, or declare variables in the beginning of a block, e.g:

void foo()
{
    int x = 0;
    int TabCnt;
    for (TabCnt = 0; TabCnt < 10; TabCnt++)
    {
        x++;
    }
}

edited Jan 09 '19 at 09:16

Supr

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answered Mar 24 '15 at 08:59

Yu Hao

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Ok, I thought it might be something like that. Thanks! – Simon Mar 24 '15 at 09:11

score 0 · Answer 2 · answered Mar 24 '15 at 09:01

0

int TabCnt;

for(TabCnt = 0; TabCnt < 10; TabCnt++)

will solve your problem as it seems your compiler doesn't support C99.

Try compiling with -std=c99 since the syntax you have is allowed only from C99

answered Mar 24 '15 at 09:01

Gopi

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score 0 · Answer 3 · answered Aug 08 '23 at 07:43

For anyone looking how to enable c99 in Code Composer Studio (the editor used to develop embedded C for Texas Instruments microcontrollers), go to Project -> Properties and then in the left hand side go to Build -> C2000 compiler -> Advanced Options -> Language options. You can select c99 in the drop-down menu of the "C Dialect" parameter.

Note: I am using CCS v11.2.0.00007

Declaring a variable inside a for loop; getting error with c2000 compiler

3 Answers3