All: fix warnings when compiling with -Wswitch-enum

[fhuberts]

Signed-off-by: Ferry Huberts ferry.huberts@pelagic.nl

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[coveralls]

Coverage remained the same at 100.0% when pulling cdbc50b on fhuberts:fix-switch-enum into 910fabf on nlohmann:develop.

[nlohmann]

I am surprised that fixing this warning does not come at the expense of another warning coming up - at least in the past, we always have had to suppress one of the switch warnings.

Can you please remove the -Wno-switch-enum from https://github.com/nlohmann/json/blob/develop/cmake/ci.cmake#L102 and replace -Wno-switch-enum by -Wswitch-enum in https://github.com/nlohmann/json/blob/develop/cmake/ci.cmake#L329? Then the CI is actually checking whether the warning is really gone.

[fhuberts]

I am surprised that fixing this warning does not come at the expense of another warning coming up - at least in the past, we always have had to suppress one of the switch warnings.

Can you please remove the -Wno-switch-enum from https://github.com/nlohmann/json/blob/develop/cmake/ci.cmake#L102 and replace -Wno-switch-enum by -Wswitch-enum in https://github.com/nlohmann/json/blob/develop/cmake/ci.cmake#L329? Then the CI is actually checking whether the warning is really gone.

Done.
Works fine for me on Fedora 34.

g++ (GCC) 11.2.1 20210728 (Red Hat 11.2.1-1)
Copyright (C) 2021 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.

[gregmarr]

@nlohmann The warning that you're thinking of is -Wcovered-switch-default which is part of -Weverything on Clang. This will warn because these switches have all the cases covered AND have a default: statement.

#555 (comment)

See also #889 and #890

[fhuberts]

Works fine on Debian 10.10 with gcc as well.
So it indeed seems that conflicting options are to blame here.

[fhuberts]

I checked the other issues that are mentioned (did not see them before).

If the currently feeling is the same as before, then no problem because I'll just keep this as a private patch in our repo.

Personally I do prefer the gcc way because it makes the code explicit and therefore easier to read and reason about.
My 2 cents.

[nlohmann]

I think the warnings raised by Clang and GCC all complain about some switches which have not yet been touched by the PR. I think they can be fixed similarly.

[fhuberts]

I'm a bit surprised that there are now errors on files I didn't touch.
Like /home/runner/work/json/json/include/nlohmann/detail/input/binary_reader.hpp.
I compiled as prescribed.

[nlohmann]

I'm a bit surprised that there are now errors on files I didn't touch.
Like /home/runner/work/json/json/include/nlohmann/detail/input/binary_reader.hpp.
I compiled as prescribed.

Did you compile the unit test suite?

[fhuberts]

I'm a bit surprised that there are now errors on files I didn't touch.
Like /home/runner/work/json/json/include/nlohmann/detail/input/binary_reader.hpp.
I compiled as prescribed.

Did you compile the unit test suite?

I followed the instructions of the PR, I did as described here: https://github.com/nlohmann/json/blob/develop/README.md#execute-unit-tests

[nlohmann]

I see - but I guess the CI uses a different set of warnings.

[fhuberts]

Then if you let me know how I should compile it, I'll see if I can fix those warnings as well.

[nlohmann]

Try this:

mkdir build
cd build
cmake .. -DJSON_CI=ON

Then

make ci_test_gcc

for GCC with all flags and

make ci_test_clang

for Clang with all flags.

[nlohmann]

(Or just check out the results of https://github.com/nlohmann/json/pull/2927/checks?check_run_id=3314908857 and https://github.com/nlohmann/json/pull/2927/checks?check_run_id=3314909773)

[fhuberts]

Adjusted.
make ci_test_gcc didn't work for me, the clang build did work
Might be because I have ccache installed

[nlohmann]

Looks good to me.

[nlohmann]

Please also add // LCOV_EXCL_LINE to the added branches, as the coverage has decreased.

See https://coveralls.io/builds/42131077.

[nlohmann]

Looks good to me.

[nlohmann]

Thanks for the patience! I will merge this as soon as the CI is done.

[fhuberts]

success!
tnx!