[SAM core 1.6.5] 'max' was not declared in this scope

[per1234]

Using Arduino IDE 1.6.7 2015/11/04 03:53 with Arduino SAM Boards 1.6.5 and Windows 7 64 bit

Maybe the same issue solved in the SAMD core by: arduino/ArduinoCore-samd@a546da2

Sketch:

byte x = max(1, 2);
void setup() {
}
void loop() {
}

Error when compiled with Due selected in Boards menu:

sketch_nov04a:1: error: 'max' was not declared in this scope
 byte x = max(1, 2);
                  ^
exit status 1
'max' was not declared in this scope

The sketch compiles fine with Arduino SAM Boards 1.6.4 or with an AVR board selected

Reported at http://forum.arduino.cc/index.php?topic=357312.msg2463840#msg2463840

[odbol]

haha just found this same problem.

Here's a bit more info, seems that there are some redefinitions loose in the USB_device.h file:

In file included from /Users/tyler/Library/Arduino15/packages/arduino/hardware/sam/1.6.5/system/libsam/chip.h:66:0,
                 from /Users/tyler/Library/Arduino15/packages/arduino/hardware/sam/1.6.5/cores/arduino/Arduino.h:42,
                 from /var/folders/lh/s5d4j74j4kgg0cydtkjz46780000gn/T/build2e4adf3305ada44c20a2a50ec8690852.tmp/sketch/TestMax.ino.cpp:1:
/Users/tyler/Documents/Arduino/TestMax/TestMax.ino: In function 'void setup()':
TestMax:4: error: 'max' was not declared in this scope
     int newBpm = min(max(0, 5), 6);
                              ^
/Users/tyler/Library/Arduino15/packages/arduino/hardware/sam/1.6.5/system/libsam/include/USB_device.h:364:32: note: in definition of macro 'Min'
 #define Min(a, b)           (((a) < (b)) ?  (a) : (b))
                                ^
/Users/tyler/Documents/Arduino/TestMax/TestMax.ino:4:18: note: in expansion of macro 'min'
     int newBpm = min(max(0, 5), 6);
                  ^
exit status 1
'max' was not declared in this scope 

For me, using Min() worked but min() did not. My guess is that the precompiler is running out of recursion? For instance, this didn't work:

    int newBpm = min(max(0, 5), 6);

But this does:

    int newBpm = Min(Max(0, 5), 6);

[cmaglie]

I confirm the issue, this is a regression on the SAM core, as @per1234 said, it may be something similar to the same issue appeared on the Zero.

[cmaglie]

I've pushed a fix for this bug:
f678ad4

This is a major bug, we are probably going to do another release of the SAM core only to fix this one, please check if this fix is effective.

[per1234]

The fix works for me with my simple test sketch and the sketch from the user who originally reported the issue. I will ask them to test also and report their findings if they don't have a GitHub account.

[per1234]

The user who reported the issue on the Arduino forum says the fix resolved their problem with max() and Due: http://forum.arduino.cc/index.php?topic=357312.msg2466769#msg2466769

[cmaglie]

The fix has been released.

@per1234
Thanks for the great feedback!