+- MISRA Discussion Forums (https://forum.misra.org.uk)
+-- Forum: MISRA C (https://forum.misra.org.uk/forumdisplay.php?fid=4)
+--- Forum: MISRA C:2012 and MISRA C:2023 guidelines (https://forum.misra.org.uk/forumdisplay.php?fid=21)
+---- Forum: 8.8 Declarations and defnitions (https://forum.misra.org.uk/forumdisplay.php?fid=163)
+---- Thread: Definition of "object" (/showthread.php?tid=1486)
Definition of "object" - mz99 - 17-04-2019
The word "object" is used in some rules of MISRA-C:2012. (e.g. Rule-8.9)
What is the definition of "object" in MISRA-C:2012?
Which of the following are considered as "object" in MISRA-C:2012?
- Variable
- Const-qualified variable
- Function
- Object-like macro
- Function-like macro
Re: Definition of "object" - dg1980 - 17-04-2019
First sentence here: https://en.wikipedia.org/wiki/Object_(computer_science)
Anything else would really surprise me:) - but let's wait for an official reply.
Re: Definition of "object" - twakita - 23-04-2019
(This is not offical reply from MISRA)
"object" is defined in ISO-C. (MISRA C is a subset of ISO-C.)
object (ISO/IEC 9899 section 3.14):
region of data storage in the execution environment,
the contents of which can represent values (1)(2)
Mostlikely, "object" meanings RAM area which is assigned for a variable.
-- refs --
(1) ISO/IEC 9899: 1990,Programming languages ― C, ISO, 1990
(2) ISO/IEC 9899: 1990,Programming languages ― C, ISO, 1999
Re: Definition of "object" - mz99 - 26-04-2019
I accidentally posted the same replies...
Thank you for the comments.
So, according to the definition of "object", would they be regarded as an "object", or NOT an "object"?
Variable -> "object", because it's stored in RAM.
Const-qualified variable -> ?, depends on whether it's stored in ROM or RAM.
Function -> not "object", because it can't represent values.
Object-like macro -> not "object", because it's not stored in RAM.
Function-like macro -> not "object", because it's not stored in RAM.
Re: Definition of "object" - mz99 - 26-04-2019
.
Re: Definition of "object" - mz99 - 26-04-2019
.
Re: Definition of "object" - misra-c - 02-05-2019
The MISRA C:2012 guidelines uses the definition as the C99 standard. ( see section 3.14 and 6.2.1 ). Regarding your specific examples:
Code:
* Variable // object
* Const-qualified variable // object
* Function // not an object
* Object-like macro // not an object, but may expand to an object
* Function-like macro // not an object, but may expand to an objectFor example:
Code:
int x; // object
int fn(int y); // function
#define MYMAC(Z) Z
int MYMAC(r) = 3; // expands to int r = 3; which is an object definition
MYMAC(fn)(x); // expands to fn(x); which is a function call