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I have noticed that I get error messages or I don't sometimes depending on optimization level. For example, I had a statement that tried to store a value into code space and at opt level zero, I got an error saying that it couldn't convert the lvalue. I understood this. However, at opt level 8, I got no error and in fact the 'optimizer' simply left out the offending line. Why should it do this? If it is an error, it should report it and not throw the code away.
We tried to duplicate your problem, but no matter which optimization level or compiler version we are using we are getting a correct error message. You your case must be different from ours. How can we duplicate it? Our test file is as follows:
stmt level source 1 struct { 2 unsigned char v; 3 unsigned char code *ptr; 4 } s; 5 6 void main (unsigned char t) { 7 1 *((unsigned char * )s.ptr) = t; 8 1 } *** ERROR C183 IN LINE 7 OF Y.C: unmodifiable lvalue
Well,I am puzzled. I tried your simple program and got the error on both opt level 0 and opt level 8. I am running v2.20a by the way. So, I tried making it a little bit more like our real program. This is what I did. #define BYTE int struct { unsigned char v; void code *ptr; } s; void chooseOne(BYTE a) { int i; switch(a) { case 1: i=1; break; case 2: i=2; break; case 3: *((BYTE * )s.ptr) = a; break; case 4: i=4; break; default: break; } } void main (void) { int a=3; chooseOne(a); } I set up the target options the same as our real program. I got the same error at both opt levels. I don't know why I don't get the error with opt level 8 with our actual code. I have asked my colleague who originally wrote it to try to look into it. At least he was able to reproduce my results on his computer so it is not just with my machine.
#define BYTE int
typedef int TwoBytes;
typedef int TwoBytes; #define TWO_BYTE_TYPE
Sorry, but we need an example that allows us to duplicate your initial problem. If you have a more complex example, you may want to send this to: support.intl@keil.com