Build fails with gcc 11 / C++20

[urp]

Problem

Compiler error when including node.h with NAPI_VERSION=8:

napi.h:2477:60: error: expected unqualified-id before ‘)’ token
 2477 |     TypedThreadSafeFunction<ContextType, DataType, CallJs>();
      |                                                            ^
/home/adiletkutmanov/Development/lauda_measurement_napi/node_modules/node-addon-api/napi.h:2479:33: error: expected ‘)’ before ‘tsFunctionValue’
 2479 |         napi_threadsafe_function tsFunctionValue);
      |                                 ^~~~~~~~~~~~~~~~
      |                                 )
/home/adiletkutmanov/Development/lauda_measurement_napi/node_modules/node-addon-api/napi.h:2478:59: note: to match this ‘(’
 2478 |     TypedThreadSafeFunction<ContextType, DataType, CallJs>(
      |                                                           ^
In file included from /home/adiletkutmanov/Development/lauda_measurement_napi/node_modules/node-addon-api/napi.h:2725,
                 from /home/adiletkutmanov/Development/lauda_measurement_napi/src/lauda_measurement.cpp:1:
/home/adiletkutmanov/Development/lauda_measurement_napi/node_modules/node-addon-api/napi-inl.h:4764:8: error: no declaration matches ‘Napi::TypedThreadSafeFunction<ContextType, DataType, CallJs>::TypedThreadSafeFunction()’
 4764 | inline TypedThreadSafeFunction<ContextType, DataType, CallJs>::
      |        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/adiletkutmanov/Development/lauda_measurement_napi/node_modules/node-addon-api/napi-inl.h:4764:8: note: no functions named ‘Napi::TypedThreadSafeFunction<ContextType, DataType, CallJs>::TypedThreadSafeFunction()’
In file included from /home/adiletkutmanov/Development/lauda_measurement_napi/src/lauda_measurement.cpp:1:
/home/adiletkutmanov/Development/lauda_measurement_napi/node_modules/node-addon-api/napi.h:2347:9: note: ‘class Napi::TypedThreadSafeFunction<ContextType, DataType, CallJs>’ defined here
 2347 |   class TypedThreadSafeFunction {​​​​​​​
      |         ^~~~~~~~~~~~~~~~~~~~~~~
In file included from /home/adiletkutmanov/Development/lauda_measurement_napi/node_modules/node-addon-api/napi.h:2725,
                 from /home/adiletkutmanov/Development/lauda_measurement_napi/src/lauda_measurement.cpp:1:
/home/adiletkutmanov/Development/lauda_measurement_napi/node_modules/node-addon-api/napi-inl.h:4771:8: error: no declaration matches ‘Napi::TypedThreadSafeFunction<ContextType, DataType, CallJs>::TypedThreadSafeFunction(napi_threadsafe_function)’
 4771 | inline TypedThreadSafeFunction<ContextType, DataType, CallJs>::
      |        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/adiletkutmanov/Development/lauda_measurement_napi/node_modules/node-addon-api/napi-inl.h:4771:8: note: no functions named ‘Napi::TypedThreadSafeFunction<ContextType, DataType, CallJs>::TypedThreadSafeFunction(napi_threadsafe_function)’
In file included from /home/adiletkutmanov/Development/lauda_measurement_napi/src/lauda_measurement.cpp:1:
/home/adiletkutmanov/Development/lauda_measurement_napi/node_modules/node-addon-api/napi.h:2347:9: note: ‘class Napi::TypedThreadSafeFunction<ContextType, DataType, CallJs>’ defined here
 2347 |   class TypedThreadSafeFunction {​​​​​​​
      |         ^~~~~~~~~~~~~~~~~~~~~~~

Workarounds:

• Use gcc 11 with c++17
• Use gcc 10 with c++20

[KevinEady]

Hi @urp ,

I am able to replicate this issue the example in the readme.

Start container on gcc-11.1:

docker run -it --rm -v $(pwd):/app gcc:11.1 /bin/bash

And run these commands:

apt-get update && apt-get install -y cmake
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.38.0/install.sh | bash

export NVM_DIR="$HOME/.nvm"
[ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"  # This loads nvm
[ -s "$NVM_DIR/bash_completion" ] && \. "$NVM_DIR/bash_completion"  # This loads nvm bash_completion
nvm install node

cd /tmp
git clone --branch add-typed-tsfn-example https://github.com/nodejs/node-addon-examples.git
cd node-addon-examples/typed_threadsafe_function/node-addon-api
npm i

I have noticed that using c++20 on my Mac (Apple clang version 12.0.0 (clang-1200.0.32.29)) does work. Not sure exactly how to proceed. We can discuss in the Node-API weekly meeting

cc: @mhdawson

[richardlau]

FWIW C++20 support in gcc 11 is marked experimental: https://gcc.gnu.org/onlinedocs/gcc-11.1.0/gcc/C-Dialect-Options.html#C-Dialect-Options

[KevinEady]

Thanks @richardlau for the insight! I am in the process of reporting the bug to GCC compiler team, currently waiting account creation.

@urp, unfortunately I think we will have to go with "known incompatibility" until GCC updates their compiler; since other c++20 compilers work, it is strictly an issue with GCC.

I will keep this issue open until I can link the GCC bug report in this ticket and our setup documentation page.

Thanks, Kevin

[KevinEady]

This issue will be fixed when the associated PR is merged.

Thanks for reporting!

Edit: Please see the not-a-bug bug report comment for more information.