AVR Freaks

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Yes gcc is full of holes but some are useful. Problem is, some programmers will rely on them working and then updating to a new avr-gcc version will break the code (in fact, just reveal holes already present).

Here is a small C++ example, it's kind of my pet issue 

#include <stdint.h>
#define MMREGADDR 0x20

#define MMREG (*(volatile uint8_t*) MMREGADDR)

typedef struct
{
  volatile uint8_t data;
} port_t;

#define MMREG_s (*(port_t*) MMREGADDR)

// The following 2 lines should always generate errors, since they violate C++ standard regarding valid constant expressions
// (they include a reinterpret_cast, in fact 2: int -> pointer -> int)
constexpr uint16_t mmreg_addr = (uint16_t) &(MMREG_s.data);   // v5 compiles (AS7), v7 compiles (Arduino), v9, v10 fail
//constexpr uint16_t mmreg_addr = (uint16_t) &MMREG;              // v5 compiles (AS7), v7 fails (Arduino), v9, v10 fail

int main(void){
  return mmreg_addr;
}

Basically this is a cast from int to pointer and back to int. Even though the compiler actually knows this value at compile time and could use it as a constant expression, the C++ standard says it should pretend it doesn't and generate an error (I don't agree with the standard here, but hey, I hear these people are very smart so whatever they say must surely be right).

Only newer versions of avr-gcc do the check, version 7 currently used in the Arduino suite does the check only in some situations. It's quite a mess.

edit: link to live compiler (v5 and v9 only) https://godbolt.org/z/d9K4sY

I guess I'm ranting because I've seen people using things like &PORTB as template arguments, because AS7 will accept that even though it's invalid code. I blame Microchip for still using avr-gcc v5 in their official toolchain when it has so many bugs.

Besides you added features like the optimized ISR prologue/epilogue to one of the v8 sub-versions, right? An  important feature IMO. Yet lots of people won't ever benefit from it because v5 ships with AS7 and v7 with Arduino.

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The work is not that much the problem. Dealing with a mismanaged project, terrible infrastructure and rude ["co-workers and management"]

Sorry to have to tell you, but those sorts of problems are ALWAYS "part of the work."  :-)

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I would guess... no.

I received a ping on the bounty payout today.   It looks legit.  Thanks for the work , saaadu.   Here is the link: gcc issue on avr CCmode