LAUNCHXL-F28P55X: Definition/Declaration of _assert in C2000 Compiler Library

Emily Birch

Tool/software:

I am getting a new linting tool set up to run with my project, and I am running into an issue with the _assert(...) function/definition. From ccs2020\ccs\tools\compiler\ti-cgt-c2000_22.6.2.LTS\lib\src\assert.h, the _assert(...) call is made. However, I cannot find anywhere where this is defined or where it is documented, and so naturally my linter raises an error that it cannot find the declaration of it. Where does _assert(...) come from?

#if defined(NDEBUG)
#define assert(_ignore) ((void)0)
#elif defined(NASSERT)
#define assert(_expr)   _nassert(_expr)
#else
#if (defined(__clang__) && defined(__arm__)) || \
    (defined(_AEABI_PORTABILITY_LEVEL) && _AEABI_PORTABILITY_LEVEL != 0)
     extern void __aeabi_assert(const char *expr, const char *file, int line);
     #define assert(__e) ((__e) ? (void)0 : \
	         __aeabi_assert(#__e, __FILE__, __LINE__))
#else
     #define assert(_expr)   _assert((_expr) != 0,      \
                    "Assertion failed, (" _STR(_expr) "), file " __FILE__ \
                    ", line " _STR(__LINE__) "\n")
#endif /* _AEABI_PORTABILITY_LEVEL, __clang__ */
#endif /* NDEBUG, NASSERT */

5 days ago

+1 George Mock 5 days ago

TI__Guru**** 249360 points

Emily Birch said:
Where does _assert(...) come from?

It is an undocumented intrinsic.

Please consider this example.

/* file.c */
#include <assert.h>

void example(int arg)
{
    assert(arg > 0);
    /* processing with arg that presumes arg is positive */
}

Compile it ...

cl2000 --opt_level=2 --src_interlist file.c

Using optimization level 2 makes the generated assembly easier to understand. (That's not always true, but it is in this case.) The option --src_interlist causes the assembly file to be kept, and comments are added. Inspect the resulting file.asm. These are the key lines ...

        CMPB      AL,#0                 ; [CPU_ALU] |6| 
        B         $C$L1,GT              ; [CPU_ALU] |6| 
        ; branchcc occurs ; [] |6| 
;***  	-----------------------    return;
        MOVL      XAR4,#$C$FSL1         ; [CPU_ARAU] |6| 
        LCR       #__abort_msg          ; [CPU_ALU] |6| 
        ; call occurs [#__abort_msg] ; [] |6| 
$C$L1:

The argument (in the register AL) is compared against 0. It if is less than or equal to 0, the function __abort_msg is called. This function is supplied in the compiler RTS library.

Thanks and regards,

-George

0 Emily Birch 1 day ago in reply to George Mock

Prodigy 110 points

Thanks George.

That would explain it, thanks. Stubbing that intrinsic out made my linter happy, so that was the right route to take.

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LAUNCHXL-F28P55X: Definition/Declaration of _assert in C2000 Compiler Library