28 expression must have a constant value - line working in other compiler but not in TI compiler

Bilal Dastagir

Hello there,

I am having problem with line in my code which is

NOTE: typedef unsigned char mz_uint8;

mz_uint8 pnghdr[41]={0x89,0x50,0x4e,0x47,0x0d,0x0a,0x1a,0x0a,0x00,0x00,0x00,0x0d,0x49,0x48,0x44,0x52,0,0,(mz_uint8)(w>>8),(mz_uint8)w,0,0,(mz_uint8)(h>>8),(mz_uint8)h,8,"\0\0\04\02\06"[num_chans],0,0,0,0,0,0,0,(mz_uint8)(*pLen_out>>24),(mz_uint8)(*pLen_out>>16),(mz_uint8)(*pLen_out>>8),(mz_uint8)*pLen_out,0x49,0x44,0x41,0x54};

I am to implement code from this open source file

https://code.google.com/p/miniz/source/browse/trunk/miniz.c#2780

What is wrong with line of code ? It is working other compiler but not TI compiler? How to get rid of this?

Error Detail :

Description Resource Path Location Type
#28 expression must have a constant value mbad1CODE.c /mmcsd2 line 2818 C/C++ Problem

Thanks in Advance.

over 12 years ago

0 Gunay Turan over 12 years ago

Intellectual 595 points

Hi Bilal,

You can put / at the end of each line which makes the compiler understand that you will continue on the next line. Also if you divide the lines after the commas it should work either.

Regards,

Gunay.

0 Ilmars over 12 years ago

Guru 46710 points

Bilal Dastagir said:
How to get rid of this?

If you have an array initialization that does not work, like this:

char arr[4] = {0,0,(char)(w>>8),0};

Then rewrite it as follows:

char arr[4] = {0,0,0,0};
arr[2] = (char)(w>>8);

0 Ilmars over 12 years ago in reply to Gunay Turan

Guru 46710 points

Gunay Turan said:
You can put / at the end of each line

Put \ at the end of each line.

0 Gunay Turan over 12 years ago in reply to Ilmars

Intellectual 595 points

Ilmars said:

[Put \ at the end of each line.

Oops sorry.

I think I also misunderstood the question, nevermind if (probably) it does not help

0 Bilal Dastagir over 12 years ago in reply to Ilmars

Prodigy 30 points

That's was very helpful and it solved that error.

0 Jens-Michael Gross over 12 years ago in reply to Ilmars

Guru 227245 points

Ilmars said:
If you have an array initialization that does not work, like this:

You should add why it doesn't work :)

Initializing an array is different from assigning something to an array. For initialization, the compiler just copies stored values to the array. These values need to be precompiled and have to be known at compiletime and therefore constant.

Expressions like *data can only be evaluated at runtime and must not appear in an initialization.

0 Ilmars over 12 years ago in reply to Jens-Michael Gross

Guru 46710 points

Jens-Michael Gross said:
You should add why it doesn't work :)

I left this part especially for you, can't compete here :DD

0 Chester Gillon over 12 years ago

Guru 92251 points

Bilal Dastagir said:
What is wrong with line of code ? It is working other compiler but not TI compiler? How to get rid of this?

It is a GCC extension to allow local array variables to be initialized from other variables. Found that with MSP430 compiler v4.1.6 if enabled GCC extensions then the compiler accepted such an array initialization (only as a local array variable inside a function).

void main(void)
{
int w = 257;
char arr[4] = {0,0,(char)(w>>8),0};
}

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28 expression must have a constant value - line working in other compiler but not in TI compiler