CCS/SW-EK-TM4C123GXL: Reference to string not recognised.

William Herschel

Part Number: SW-EK-TM4C123GXL

Tool/software: Code Composer Studio

Hi, I am trying to use string a = "abc" for example but I cannot get the compiler to recognise the type string. I think it is trying to compile c++, but whatever I do string does not got red like it does when declaring int or char for example in the designer window. Thank you.

over 5 years ago

0 Ki over 5 years ago

TI__Guru**** 462941 points

Hi William,

I'm a little confused as to the root issue. Are getting build errors when compiling the file? Or is the issue with the functionality in the editor (syntax highlighting, static code analysis, etc)

Thanks

0 William Herschel over 5 years ago in reply to Ki

Intellectual 640 points

Hi ki,

Thanks for your reply.

Certainly when I try to build it is says the word string is not recognised and so the compile fails, but I already know it will because it was not recognised by the editor – it should have gone red as with the functions it does recognise. I hope that makes it a bit clearer.

0 William Herschel over 5 years ago in reply to William Herschel

Intellectual 640 points

For example,

    float x = 122.968;
    float y = x / 17.93;
    string a = "abc";
    char outStr[] = "In the name of! No String functions\n";

    UARTprintf("Result: y = %s",outStr);

the editor recognises float, char and UARTprintf but not string

0 Keith Barkley over 5 years ago in reply to William Herschel

Guru 42085 points

Are you using C++ or C?

C has no string class, and AFAIK, you need to include the "string" header for C++.

0 William Herschel over 5 years ago in reply to Keith Barkley

Intellectual 640 points

As far as I know the compiler treats the code as C and C++. I have #include <string>
but it makes no difference.

0 Ki over 5 years ago in reply to William Herschel

TI__Guru**** 462941 points

William Herschel said:
As far as I know the compiler treats the code as C and C++. I have #include <string>

If the code is in a source file with a *.c extension, the compiler will treat it as a C source file only. If you want to treat it as C++, you must explicitly enable it in the build options:

Also add the below line after your include statements

using std::string;

Thanks

0 William Herschel over 5 years ago in reply to Ki

Intellectual 640 points

I thought I’d read if the file has .C extension it is treated as C++ but I could be wrong. But I have that check box ticked in any case and the problem is still there.

0 Ki over 5 years ago in reply to William Herschel

TI__Guru**** 462941 points

Did you also add:

using std::string;

after your include statements?

0 William Herschel over 5 years ago in reply to Ki

Intellectual 640 points

Just tried that and it says std has no member string

0 Ki over 5 years ago in reply to William Herschel

TI__Guru**** 462941 points

Please attach a small test case that can reproduce the issue for you. I would need the whole project and source file needed to build.

Thanks

0 William Herschel over 5 years ago in reply to Ki

Intellectual 640 points

Will this be enough ?

/**
* main.c
*/
using std::string;
int main(void)
{
string = "abc";
return 0;
}
It gives the errors. The compiler flag is set to treat the file as C++

Thanks

0 Ki over 5 years ago in reply to William Herschel

TI__Guru**** 462941 points

Try this:

/**
 * main.c
 */
#include <string>

using std::string;
int main(void)
{
    string a = "abc";
    return 0;
}

0 William Herschel over 5 years ago in reply to Ki

Intellectual 640 points

Yes that seems to be an improvement – the code compiles now. The word string is not highlighted in the editor like the other declarations though. This may be a different question:

In the original code

string a = "abc";

UARTprintf("Result: String a = %s",a);

gives

#1554-D non-POD class type passed through ellipsis LearnUART.C

Is there a simple reason for this?

Thanks.

0 William Herschel over 5 years ago in reply to William Herschel

Intellectual 640 points

I've answered my own question by Googling

UARTprintf("Result: String a = %s",a.c_str());

Many thanks for your help.

0 Keith Barkley over 5 years ago in reply to William Herschel

Guru 42085 points

"string" as a type name is not highlighted since it is not a native type.

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CCS/SW-EK-TM4C123GXL: Reference to string not recognised.