tflite-micro is breaking complex.h

[pschatzmann]

Board

Any

Device Description

The issue is with all boards: I tried with the ESP32 and a C6

Hardware Configuration

n/a

Version

latest development Release Candidate (RC-X)

IDE Name

Arduino IDE

Operating System

Linux Mint

Flash frequency

n/a

PSRAM enabled

no

Upload speed

n/a

Description

The new version (4.0.0) contains espressif__esp-tflite-micro which has a complex.h in the src directory:
~/.arduino15/packages/esp32/tools/esp32-arduino-libs/idf-release_v5.1-3662303f312/esp32/include/espressif__esp-tflite-micro/signal/src/complex.h

This is preventing that the regular complex.h from the c and c++ library can be used!
So all libraries containing complex.h are broken and will produce compile errors.

Sketch

#include <complex.h>

std::complex<double> mycomplex(10.0, 2.0);

void setup() {}

void loop() {}

Debug Message

Compile error:

/tmp/.arduinoIDE-unsaved2024315-466177-1nzbc94.mycl/sketch_apr15c/sketch_apr15c.ino:3:6: error: 'complex' in namespace 'std' does not name a template type
    3 | std::complex<double> mycomplex(10.0, 2.0);
      |      ^~~~~~~
/tmp/.arduinoIDE-unsaved2024315-466177-1nzbc94.mycl/sketch_apr15c/sketch_apr15c.ino:2:1: note: 'std::complex' is defined in header '<complex>'; did you forget to '#include <complex>'?
    1 | #include <complex.h>
  +++ |+#include <complex>
    2 | 

exit status 1

Compilation error: 'complex' in namespace 'std' does not name a template type

Other Steps to Reproduce

No response

I have checked existing issues, online documentation and the Troubleshooting Guide

• I confirm I have checked existing issues, online documentation and Troubleshooting guide.

[pschatzmann]

I messed up with the version info: of cause it is 3.0.0-rc1

[lucasssvaz]

The CPP STD header name is complex without the .h

This will compile without any issue:

#include <complex>

std::complex<double> mycomplex(10.0, 2.0);

void setup() {}

void loop() {}

[me-no-dev]

#include <complex> not <complex.h>. Would that work?

[pschatzmann]

For the indicated example it would work, but I filed the issue because some sketches which are using c libraries (some audio codecs and fft) are not compiling any more and it was too tedious to demo the issue in c.

I wanted proof the point that complex.h is broken in C!

e.g.
https://github.com/pschatzmann/esp32-fft
https://github.com/pschatzmann/arduino-codec2
https://github.com/pschatzmann/kissfft

[me-no-dev]

If you think that complex.h is broken, maybe file an issue in the toolchain repository: https://github.com/espressif/crosstool-NG/issues

[pschatzmann]

So it is the toolchain and not arduino-esp32 that decides to include and make available tflite-micro ?

[me-no-dev]

@pschatzmann we did resolve your original issue. For the others it's too tedious for you to properly report. I am still trying to offer you a way to resolve the problem, for which I only know that it has to do with complex.h.

[pschatzmann]

I can create an additional simple example (on top of the mentioned libraries that give compile errors) if that helps you to understand the issue. Please let me know!

[me-no-dev]

Yes it will. thanks!

[pschatzmann]

In Arduino, create a new tab: test.c with the following lines:

#include <complex.h> 
double complex  z  = 3.2 + 4.1 * I; 

This gives the following error:

In file included from /tmp/.arduinoIDE-unsaved2024316-5867-1odft3o.2uay/sketch_apr16a/test.c:1:
/home/pschatzmann/.arduino15/packages/esp32/tools/esp32-arduino-libs/idf-release_v5.1-3662303f312/esp32/include/espressif__esp-tflite-micro/signal/src/complex.h:23:10: error: expected '=', ',', ';', 'asm' or '__attribute__' before '<' token
   23 | template <typename T>
      |          ^
/tmp/.arduinoIDE-unsaved2024316-5867-1odft3o.2uay/sketch_apr16a/test.c:2:17: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'z'
    2 | double complex  z  = 3.2 + 4.1 * I;
      |                 ^

exit status 1

Compilation error: expected '=', ',', ';', 'asm' or '__attribute__' before 'z'

Deleting the file ~/.arduino15/packages/esp32/tools/esp32-arduino-libs/idf-release_v5.1-3662303f312/esp32/include/espressif__esp-tflite-micro/signal/src/complex.h is correcting the issue!

So this is the root cause of the issue! and any Arduino library using complex.h in a c file will not work any more.

This example is working properly in prior versions

[pschatzmann]

I cross posted the issue in tflite-micro as well, since it could be resolved easily there

[me-no-dev]

This would be easily fixable in the header itself. Seems to not have guards for CPP and also does not include the next complex.h. With the following changes your example compiled

[pschatzmann]

Just for my better understanding: am I correct in the assumption that it was the decision of the arduino-esp32 project to include tflite-micro into the basic functionality instead of relying on an Arduino library ?

From my point of view an Arduino library would be a better fit and would provide much more flexibility.

[me-no-dev]

differences is that this "version" of tflite is written to support the hardware accelerators in some of our chips, so on S3 you would get better results. I do not see how external Arduino library would help in this case. The header comes from tflite itself.

[me-no-dev]

Also tflite is precompiled, so you only need to link against it and not compile the whole thing (it's a lot)