Fix Clang 19 -Wc++20-extensions warning

[archie2x]

Description

1. IInitial work (commit 5) removes WS/unrelated changes from PR Fix: Clang 19 -Wc++20-extensions warning #2910  #2934 meant to address issue Clang 19 -Wc++20-extensions warning #2910.
2. commit 6 discards changes from PR Fix: Clang 19 -Wc++20-extensions warning #2910  #2934 in favor of correct clang-version specific warning suppression pragmas for CATCH_INTERNAL_SUPPRESS_ZERO_VARIADIC_WARNINGS

GitHub Issues

#2910

Minimal reproduction

Tested with:

// test.cpp
#include <catch2/catch_template_test_macros.hpp>
#include <catch2/catch_test_macros.hpp>

#include <vector>

TEMPLATE_TEST_CASE( "one-arg", "[bar]", int)
{
	std::vector<TestType> vec;
	vec.push_back(2);
}

> clang-${VERSION} -I Catch2/src -I ${GENERATED_INCLUDES} -Wall -Wextra -Wpedantic -Werror -c test.cpp 

Patch Results

Catch2	Ubuntu clang-19	Ubuntu clang-20	OSX clang-19
devel	fail	success	fail
patch	success	success	success

Error seen (clang-19 only):
test.cpp:6:1: error: passing no argument for the '...' parameter of a variadic macro is a C++20 extension [-Werror,-Wc++20-extensions]

[ChrisThrasher]

I'm still seeing the same problem present in #2934 as well as this implementation.

[archie2x]

In my tests, (osx/linux, arm64) this seemed to cause other problems.

For anybody w/ cmake I'm going with the following and moving on:

if(CMAKE_CXX_STANDARD EQUAL 17
   AND CMAKE_CXX_COMPILER_ID STREQUAL "Clang"
   AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL "19.0.0")
  # Fix for https://github.com/catchorg/Catch2/issues/2910 TEMPLATE_TEST_CASE()
  # "error: passing no argument for the '...' parameter of a variadic macro is a
  # C++20 extension [-Werror,-Wc++20-extensions]"
  target_compile_options(Catch2 INTERFACE -Wno-c++20-extensions)
endif()

[archie2x]

Pretty sure commit 6 is the right thing to do here. Test clang-{19,20} for simple:

#include <catch2/catch_template_test_macros.hpp>
#include <catch2/catch_test_macros.hpp>

#include <vector>

TEMPLATE_TEST_CASE( "one-arg", "[bar]", int)
{
	std::vector<TestType> vec;
	vec.push_back(2);
}

TEMPLATE_TEST_CASE("two-arg", "[bar]", int, float) {
  std::vector<TestType> vec;
  vec.push_back(2);
}

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.98%. Comparing base (76f70b1) to head (998dda5).
Report is 1 commits behind head on devel.

Additional details and impacted files

@@           Coverage Diff           @@
##            devel    #2968   +/-   ##
=======================================
  Coverage   90.98%   90.98%           
=======================================
  Files         198      198           
  Lines        8599     8599           
=======================================
  Hits         7823     7823           
  Misses        776      776           

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[horenmar]

Ugh, the differences in the warning name are annoying.

The changes seem fine.

@ChrisThrasher If you want me to take a second look at something, you need to ping me on Discord. I have about 100 notifications from Catch2 on GH, and I am currently ignoring them all.

[archie2x]

Merge?

[ChrisThrasher]

I was able to test this with Catch 19 and 20 and confirm that it works. Thanks!