http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59773
Bug ID: 59773
Summary: Mixing pointers to different memory spaces shows no
warning (gcc for AVR)
Product: gcc
Version: 4.7.2
Status: UNCONFIRMED
Severity: major
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: visenri at yahoo dot es
I'll explain it with an example.
Having these strings declared:
const char __flash strF[] = "Flash";
const char strR[] = "RAM";
And a function with a 24 bit flat pointer like this:
Foo( const char __memx * str );
Calling it like this is ok (16 bit pointer is enlarged to 24 generating correct
code):
Foo(strF);
Foo(strR);
But using functions with 16 bit pointer:
FooR( const char * str ); //16 bit pointer to RAM
FooF( const char _flash * str ); //16 bit pointer to FLASH
And these variables:
const char __memx * pstr;
const char * pstrR;
const char __flash * pstrF;
These lines should show at least a warning:
FooR(strF); // same size, different memory space
FooF(strR); // same size, different memory space
FooR(pstr); // pstr is 24 bit, bigger than 16 bit ram pointer in function
FooF(pstr); // pstr is 24 bit, bigger than 16 bit flash pointer in function
pstrR = strF; // same size, different memory space
pstrF = strR; // same size, different memory space
pstrR = pstr; // pstr is 24 bit, bigger than 16 bit ram pointer
pstrF = pstr; // pstr is 24 bit, bigger than 16 bit flash pointer
Because we are going to use a ROM/FLASH pointer as a RAM pointer or the other
way.
