equivalent of old C code

**ekoc** · 06-11-2015

this code

Code:

unsigned char *fs;
u32 fssize;

fssize = *(((u32 *)fs)++);

returns

Code:

lvalue required as increment operand

error with gcc-4.7. I change it to

Code:

unsigned char *fs;
u32 fssize;
u32 * u32fs;

u32fs = ((u32 *)fs);
*u32fs = *u32fs++;
fssize = *u32fs;

But application does not work as expected. Is conversion true? What is equilavent of this code ?

**laserlight** · 06-11-2015

I suspect that this was intended:

Code:

fssize = *((u32*)fs);
fs += sizeof(fssize);

My reasoning is that the cast of fs to u32* seems intended to incremented it as one would increment a u32*, i.e., to increase its value by the number of bytes of a u32. At the same time, post-increment was used, so it looks like it is also intended to assign what fs points to to fssize.

**ekoc** · 06-11-2015

@laserlight thanks,
Can you converT this

Code:

*(((unsigned char *)dest)++) = c;

**laserlight** · 06-11-2015

I have provided my reasoning for the previous example, so perhaps you can do something along the same lines, assuming that my reasoning was reasonable.

**ekoc** · 06-11-2015

I wrote this. But I am not sure it is true?

Code:

*((unsigned char *)dest) = c;

dest += sizeof(c);

**laserlight** · 06-11-2015

Does it make sense according to the context of the code? Does it work for you, e.g., does it compile and do the tests pass?

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