builtin.h does not compile with Arduino IDE g++

[martijn-heil]

I am compiling psnip using the Arduino IDE for use on a Teensy, but it results in a compilation error when including psnip/builtin/builtin.h in a .cpp file. When I include it in a .c file it works fine, so that it suggests it has something to do specifically with C++.
In another issue I've read that you intend to support C++, but that it's just less well-tested.

In file included from C:\Users\ninjoh\AppData\Local\Temp\arduino_build_148318\sketch\test.cpp:2:0:
C:\Users\ninjoh\AppData\Local\Temp\arduino_build_148318\sketch\psnip/builtin/builtin.h: In function 'unsigned char psnip_intrin_BitScanForward64(long unsigned int*, uint64_t)':
C:\Users\ninjoh\AppData\Local\Temp\arduino_build_148318\sketch\psnip/builtin/builtin.h:636:63: error: '_' was not declared in this scope
 #  define psnip_builtin_ctz64(x) PSNIP_BUILTIN__VARIANT_INT64(_,ctz)(x)
                                                               ^
C:\Users\ninjoh\AppData\Local\Temp\arduino_build_148318\sketch\psnip/builtin/builtin.h:1253:61: note: in expansion of macro 'psnip_builtin_ctz64'
   return PSNIP_BUILTIN_UNLIKELY(Mask == 0) ? 0 : ((*Index = psnip_builtin_ctz64 (Mask)), 1);
                                                             ^
C:\Users\ninjoh\AppData\Local\Temp\arduino_build_148318\sketch\psnip/builtin/builtin.h:636:65: error: 'ctz' was not declared in this scope
 #  define psnip_builtin_ctz64(x) PSNIP_BUILTIN__VARIANT_INT64(_,ctz)(x)
                                                                 ^
C:\Users\ninjoh\AppData\Local\Temp\arduino_build_148318\sketch\psnip/builtin/builtin.h:1253:61: note: in expansion of macro 'psnip_builtin_ctz64'
   return PSNIP_BUILTIN_UNLIKELY(Mask == 0) ? 0 : ((*Index = psnip_builtin_ctz64 (Mask)), 1);
                                                             ^
C:\Users\ninjoh\AppData\Local\Temp\arduino_build_148318\sketch\psnip/builtin/builtin.h:636:68: error: 'PSNIP_BUILTIN__VARIANT_INT64' was not declared in this scope
 #  define psnip_builtin_ctz64(x) PSNIP_BUILTIN__VARIANT_INT64(_,ctz)(x)
                                                                    ^
C:\Users\ninjoh\AppData\Local\Temp\arduino_build_148318\sketch\psnip/builtin/builtin.h:1253:61: note: in expansion of macro 'psnip_builtin_ctz64'
   return PSNIP_BUILTIN_UNLIKELY(Mask == 0) ? 0 : ((*Index = psnip_builtin_ctz64 (Mask)), 1);
                                                             ^
C:\Users\ninjoh\AppData\Local\Temp\arduino_build_148318\sketch\psnip/builtin/builtin.h: In function 'unsigned char psnip_intrin_BitScanReverse64(long unsigned int*, uint64_t)':
C:\Users\ninjoh\AppData\Local\Temp\arduino_build_148318\sketch\psnip/builtin/builtin.h:481:63: error: '_' was not declared in this scope
 #  define psnip_builtin_clz64(x) PSNIP_BUILTIN__VARIANT_INT64(_,clz)(x)
                                                               ^
C:\Users\ninjoh\AppData\Local\Temp\arduino_build_148318\sketch\psnip/builtin/builtin.h:1287:97: note: in expansion of macro 'psnip_builtin_clz64'
   return (PSNIP_BUILTIN_UNLIKELY(Mask == 0)) ? 0 : ((*Index = ((sizeof(Mask) * CHAR_BIT) - 1) - psnip_builtin_clz64 (Mask)), 1);
                                                                                                 ^
C:\Users\ninjoh\AppData\Local\Temp\arduino_build_148318\sketch\psnip/builtin/builtin.h:481:65: error: 'clz' was not declared in this scope
 #  define psnip_builtin_clz64(x) PSNIP_BUILTIN__VARIANT_INT64(_,clz)(x)
                                                                 ^
C:\Users\ninjoh\AppData\Local\Temp\arduino_build_148318\sketch\psnip/builtin/builtin.h:1287:97: note: in expansion of macro 'psnip_builtin_clz64'
   return (PSNIP_BUILTIN_UNLIKELY(Mask == 0)) ? 0 : ((*Index = ((sizeof(Mask) * CHAR_BIT) - 1) - psnip_builtin_clz64 (Mask)), 1);
                                                                                                 ^
C:\Users\ninjoh\AppData\Local\Temp\arduino_build_148318\sketch\psnip/builtin/builtin.h:481:68: error: 'PSNIP_BUILTIN__VARIANT_INT64' was not declared in this scope
 #  define psnip_builtin_clz64(x) PSNIP_BUILTIN__VARIANT_INT64(_,clz)(x)
                                                                    ^
C:\Users\ninjoh\AppData\Local\Temp\arduino_build_148318\sketch\psnip/builtin/builtin.h:1287:97: note: in expansion of macro 'psnip_builtin_clz64'
   return (PSNIP_BUILTIN_UNLIKELY(Mask == 0)) ? 0 : ((*Index = ((sizeof(Mask) * CHAR_BIT) - 1) - psnip_builtin_clz64 (Mask)), 1);

sample code:

test.cpp
---
#include <stdint.h>
#include "psnip/builtin/builtin.h"
#include "psnip/endian/endian.h"

void test_do_nothing(void)
{
  uint16_t be = psnip_endian_be16(200);
}

How g++ is actually called by the Arduino IDE (newlines added for clarity):

"C:\\Users\\ninjoh\\arduino-1.8.13\\hardware\\teensy/../tools/arm/bin/arm-none-eabi-g++" 
-c 
-O3 
-flto 
-fno-fat-lto-objects 
-g 
-Wall 
-ffunction-sections 
-fdata-sections 
-nostdlib
-MMD 
-fno-exceptions 
-fpermissive 
-felide-constructors 
-std=gnu++14 
-Wno-error=narrowing 
-fno-rtti 
-mthumb 
-mcpu=cortex-m4 
-fsingle-precision-constant 
-D__MK20DX256__ 
-DTEENSYDUINO=153 
-DARDUINO=10813 
-DARDUINO_TEENSY32 
-DF_CPU=24000000 
-DUSB_SERIAL_HID 
-DLAYOUT_US_ENGLISH
"-IC:\\Users\\ninjoh\\AppData\\Local\\Temp\\arduino_build_148318/pch" 
"-IC:\\Users\\ninjoh\\arduino-1.8.13\\hardware\\teensy\\avr\\cores\\teensy3"
"-IC:\\Users\\ninjoh\\arduino-1.8.13\\portable\\sketchbook\\libraries\\MFRC522\\src" 
"-IC:\\Users\\ninjoh\\arduino-1.8.13\\hardware\\teensy\\avr\\libraries\\SPI"
"-IC:\\Users\\ninjoh\\arduino-1.8.13\\portable\\sketchbook\\libraries\\Base64\\src" 
"-IC:\\Users\\ninjoh\\arduino-1.8.13\\portable\\sketchbook\\libraries\\ArduinoBearSSL\\src" 
"-IC:\\Users\\ninjoh\\arduino-1.8.13\\hardware\\teensy\\avr\\libraries\\EEPROM" 
"-IC:\\Users\\ninjoh\\arduino-1.8.13\\portable\\sketchbook\\libraries\\EDB"
"-IC:\\Users\\ninjoh\\arduino-1.8.13\\hardware\\teensy\\avr\\libraries\\Wire" 
"-IC:\\Users\\ninjoh\\arduino-1.8.13\\hardware\\teensy\\avr\\libraries\\SD"
"-IC:\\Users\\ninjoh\\arduino-1.8.13\\portable\\sketchbook\\libraries\\ArduinoJson\\src" 
"C:\\Users\\ninjoh\\AppData\\Local\\Temp\\arduino_build_148318\\sketch\\test.cpp"
-o "C:\\Users\\ninjoh\\AppData\\Local\\Temp\\arduino_build_148318\\sketch\\test.cpp.o"

[martijn-heil]

Trying at home on Linux I can reproduce the problem using the g++ bundled with the Arduino IDE v1.8.16
This time without all the related junk, just calling it directly, without arguments.

$ /usr/share/arduino/hardware/tools/arm/bin/arm-none-eabi-g++ -o /dev/null psnip/builtin/builtin.h 

psnip/builtin/builtin.h: In function 'unsigned char psnip_intrin_BitScanForward64(long unsigned int*, uint64_t)':
psnip/builtin/builtin.h:636:63: error: '_' was not declared in this scope
 #  define psnip_builtin_ctz64(x) PSNIP_BUILTIN__VARIANT_INT64(_,ctz)(x)
                                                               ^
psnip/builtin/builtin.h:1253:61: note: in expansion of macro 'psnip_builtin_ctz64'
   return PSNIP_BUILTIN_UNLIKELY(Mask == 0) ? 0 : ((*Index = psnip_builtin_ctz64 (Mask)), 1);
                                                             ^
psnip/builtin/builtin.h:636:65: error: 'ctz' was not declared in this scope
 #  define psnip_builtin_ctz64(x) PSNIP_BUILTIN__VARIANT_INT64(_,ctz)(x)
                                                                 ^
psnip/builtin/builtin.h:1253:61: note: in expansion of macro 'psnip_builtin_ctz64'
   return PSNIP_BUILTIN_UNLIKELY(Mask == 0) ? 0 : ((*Index = psnip_builtin_ctz64 (Mask)), 1);
                                                             ^
psnip/builtin/builtin.h:636:68: error: 'PSNIP_BUILTIN__VARIANT_INT64' was not declared in this scope
 #  define psnip_builtin_ctz64(x) PSNIP_BUILTIN__VARIANT_INT64(_,ctz)(x)
                                                                    ^
psnip/builtin/builtin.h:1253:61: note: in expansion of macro 'psnip_builtin_ctz64'
   return PSNIP_BUILTIN_UNLIKELY(Mask == 0) ? 0 : ((*Index = psnip_builtin_ctz64 (Mask)), 1);
                                                             ^
psnip/builtin/builtin.h: In function 'unsigned char psnip_intrin_BitScanReverse64(long unsigned int*, uint64_t)':
psnip/builtin/builtin.h:481:63: error: '_' was not declared in this scope
 #  define psnip_builtin_clz64(x) PSNIP_BUILTIN__VARIANT_INT64(_,clz)(x)
                                                               ^
psnip/builtin/builtin.h:1287:97: note: in expansion of macro 'psnip_builtin_clz64'
   return (PSNIP_BUILTIN_UNLIKELY(Mask == 0)) ? 0 : ((*Index = ((sizeof(Mask) * CHAR_BIT) - 1) - psnip_builtin_clz64 (Mask)), 1);
                                                                                                 ^
psnip/builtin/builtin.h:481:65: error: 'clz' was not declared in this scope
 #  define psnip_builtin_clz64(x) PSNIP_BUILTIN__VARIANT_INT64(_,clz)(x)
                                                                 ^
psnip/builtin/builtin.h:1287:97: note: in expansion of macro 'psnip_builtin_clz64'
   return (PSNIP_BUILTIN_UNLIKELY(Mask == 0)) ? 0 : ((*Index = ((sizeof(Mask) * CHAR_BIT) - 1) - psnip_builtin_clz64 (Mask)), 1);
                                                                                                 ^
psnip/builtin/builtin.h:481:68: error: 'PSNIP_BUILTIN__VARIANT_INT64' was not declared in this scope
 #  define psnip_builtin_clz64(x) PSNIP_BUILTIN__VARIANT_INT64(_,clz)(x)
                                                                    ^
psnip/builtin/builtin.h:1287:97: note: in expansion of macro 'psnip_builtin_clz64'
   return (PSNIP_BUILTIN_UNLIKELY(Mask == 0)) ? 0 : ((*Index = ((sizeof(Mask) * CHAR_BIT) - 1) - psnip_builtin_clz64 (Mask)), 1);

arm-none-eabi-g++ (GNU Tools for ARM Embedded Processors) 5.4.1 20160919 (release) [ARM/embedded-5-branch revision 240496]
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

[martijn-heil]

Which leads me to the central problem:

psnip/builtin/builtin.h:636:68: error: 'PSNIP_BUILTIN__VARIANT_INT64' was not declared in this scope
 #  define psnip_builtin_ctz64(x) PSNIP_BUILTIN__VARIANT_INT64(_,ctz)(x)

[martijn-heil]

PSNIP_BUILTIN__VARIANT_INT64 is not defined because it depends on
PSNIP_BUILTIN_SUFFIXINT64 which is not defined because it depends on one of

PSNIP_BUILTIN__SIZEOF_CHAR
PSNIP_BUILTIN__SIZEOF_SHRT
PSNIP_BUILTIN__SIZEOF_INT
PSNIP_BUILTIN__SIZEOF_LONG
PSNIP_BUILTIN__SIZEOF_LLONG

being equal to 64.
Their respective values are:

PSNIP_BUILTIN__SIZEOF_CHAR:   (undefined)
PSNIP_BUILTIN__SIZEOF_SHRT:   16
PSNIP_BUILTIN__SIZEOF_INT:    32
PSNIP_BUILTIN__SIZEOF_LONG:   32
PSNIP_BUILTIN__SIZEOF_LLONG:  (undefined)

For PSNIP_BUILTIN__SIZEOF_LLONG the following code defines it:

#if !defined(PSNIP_BUILTIN__SIZEOF_LLONG)
#  if   LLONG_MIN == (-0x7fLL-1) && LLONG_MAX == 0x7fLL
#    define PSNIP_BUILTIN__SIZEOF_LLONG 8
#  elif LLONG_MIN == (-0x7fffLL-1) && LLONG_MAX == 0x7fffLL
#    define PSNIP_BUILTIN__SIZEOF_LLONG 16
#  elif LLONG_MIN == (-0x7fffffffLL-1) && LLONG_MAX == 0x7fffffffLL
#    define PSNIP_BUILTIN__SIZEOF_LLONG 32
#  elif LLONG_MIN == (-0x7fffffffffffffffLL-1) && LLONG_MAX == 0x7fffffffffffffffLL
#    define PSNIP_BUILTIN__SIZEOF_LLONG 64
#  endif
#endif

But in this environment, LLONG_MIN and LLONG_MAX are apparently not defined.

CHAR_MIN is defined as 0.
CHAR_MAX is defined as (0x7f * 2 + 1).

Relevant extract from /usr/share/arduino/hardware/tools/arm/lib/gcc/arm-none-eabi/5.4.1/include-fixed/limits.h:

#if defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
/* Minimum and maximum values a `signed long long int' can hold.  */
# undef LLONG_MIN
# define LLONG_MIN (-LLONG_MAX - 1LL)
# undef LLONG_MAX
# define LLONG_MAX __LONG_LONG_MAX__

/* Maximum value an `unsigned long long int' can hold.  (Minimum is 0).  */
# undef ULLONG_MAX
# define ULLONG_MAX (LLONG_MAX * 2ULL + 1ULL)
#endif

#if defined (__GNU_LIBRARY__) ? defined (__USE_GNU) : !defined (__STRICT_ANSI__)
/* Minimum and maximum values a `signed long long int' can hold.  */
# undef LONG_LONG_MIN
# define LONG_LONG_MIN (-LONG_LONG_MAX - 1LL)
# undef LONG_LONG_MAX
# define LONG_LONG_MAX __LONG_LONG_MAX__

/* Maximum value an `unsigned long long int' can hold.  (Minimum is 0).  */
# undef ULONG_LONG_MAX
# define ULONG_LONG_MAX (LONG_LONG_MAX * 2ULL + 1ULL)
#endif

the cplusplus.com article about limits.h states the following:

LLONG_MIN, LLONG_MAX and ULLONG_MAX are defined for libraries complying with the C standard of 1999 or later (which only includes the C++ standard since 2011: C++11).

But even compiling with -std=gnu++17, the issue remains.
Changing the #include <limits.h> at the top of builtin.h to #include <climits> does solve the issue on this environment though.