Why are C++ constructors for static objects not called?

David Aldrich92784

Our design uses a number of small C++ classes. We declare the objects statically, rather than using new, because we don't want to use the heap.

For such objects we have found that their constructors are not called (or rather that the member initialisation specified by the constructors does not happen).

Why is this? Is it to do with the selection of RAM-based or ROM-based initialization?

Could I work around this issue by using the C++ 'placement new' operator?

Best regards

David

over 11 years ago

0 Archaeologist over 11 years ago

TI__Guru* 84285 points

The parser generates functions to perform the initialization and the compiler arranges for these functions to be listed in .init_array (EABI) or .pinit (COFF ABI). This list is processed by the boot routine. Are you using the default boot routines in the compiler's RTS or do you have a custom boot routine?

0 David Aldrich92784 over 11 years ago in reply to Archaeologist

Genius 3720 points

No, we don't have a custom boot routine. Currently, we are just debugging using CCS.

David

0 Archaeologist over 11 years ago in reply to David Aldrich92784

TI__Guru* 84285 points

Could you generate and post your linker map file? (Linker option --map_file=map.txt)

0 David Aldrich92784 over 11 years ago in reply to Archaeologist

Genius 3720 points

Actually, I am unable to reproduce the problem now. A colleague tells me that, in a previous project, we found that C++ constructors were not called if linker option --zero_init was set to 'off'. But I can't reproduce that issue.

Are there any compiler or linker options that would prevent C++ constructors being called for static objects?

Best regards

David

0 Archaeologist over 11 years ago in reply to David Aldrich92784

TI__Guru* 84285 points

Do not use --zero_init=off with a C or C++ program. It explicitly instructs the linker not to zero-initialize global variables. This includes the hidden guard bits that tell the RTS whether a static object has been constructed or not, so those guard bits will have a garbage value.

To my knowledge, there aren't any options that directly disable C++ constructors. Any indirect effects would have to be something dealing with initialization or linking, and --zero_init=off is the one that comes to mind.

If you cannot reproduce this problem, there's not much more I can do.

0 David Aldrich92784 over 11 years ago in reply to Archaeologist

Genius 3720 points

Thanks very much for your answer.

Best regards

David

0 guohua wei over 11 years ago in reply to David Aldrich92784

Intellectual 350 points

Hi David,

How did you solved the problem finally？ The constructor of global varibale is not called even not static in my project. I have try the zero_init..=on/off, but it no works.

Best regards.

Code Composer Studio™︎

Code Composer Studio forum

Why are C++ constructors for static objects not called?