Add CMake OTELCPP_MAINTAINER_MODE

[marcalff]

Fixes #1648

Changes

CMake OTELCPP_MAINTAINER_MODE

Add a new CMake option, OTELCPP_MAINTAINER_MODE.

Option OTELCPP_MAINTAINER_MODE=ON is supported for:

• GCC
• CLANG
• MSVC

and causes the build to fail on warnings (-Wall -Werror).

This option is useful for maintainers, when testing a build locally.

New CI builds

Add new builds in Github [CI]

• GCC (maintainer mode)
• CLANG (maintainer mode)
• MSVC (maintainer mode)

These build use OTELCPP_MAINTAINER_MODE=ON,
to enforce the build is warnings free for all compilers.

• CHANGELOG.md updated for non-trivial changes
• Unit tests have been added
• Changes in public API reviewed (no change)

[codecov]

Codecov Report

Merging #1650 (97ad7ae) into main (89eb1ec) will decrease coverage by 0.06%.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1650      +/-   ##
==========================================
- Coverage   85.82%   85.77%   -0.05%     
==========================================
  Files         169      169              
  Lines        5133     5134       +1     
==========================================
- Hits         4405     4403       -2     
- Misses        728      731       +3     

Impacted Files	Coverage Δ
...dk/metrics/exemplar/histogram_exemplar_reservoir.h	81.25% <100.00%> (+1.25%)	⬆️
ext/src/http/client/curl/http_client_curl.cc	80.31% <0.00%> (-1.13%)	⬇️

[marcalff]

To @open-telemetry/cpp-approvers

This PR adds three new builds in CI:

• CI / CMake gcc (maintainer mode)
• CI / CMake clang (maintainer mode)
• CI / CMake msvc (maintainer mode)

These new build actually fail, which is the point: find additional warnings in the code.

Failure seen by GCC:

[ 55%] Building CXX object sdk/test/trace/CMakeFiles/tracer_test.dir/tracer_test.cc.o
/home/runner/work/opentelemetry-cpp/opentelemetry-cpp/sdk/test/trace/tracer_test.cc: In member function ‘virtual opentelemetry::v1::sdk::trace::SamplingResult MockSampler::ShouldSample(const opentelemetry::v1::trace::SpanContext&, opentelemetry::v1::trace::TraceId, opentelemetry::v1::nostd::string_view, opentelemetry::v1::trace::SpanKind, const opentelemetry::v1::common::KeyValueIterable&, const opentelemetry::v1::trace::SpanContextKeyValueIterable&)’:
/home/runner/work/opentelemetry-cpp/opentelemetry-cpp/sdk/test/trace/tracer_test.cc:51:80: error: missing initializer for member ‘opentelemetry::v1::sdk::trace::SamplingResult::trace_state’ [-Werror=missing-field-initializers]
   51 |                       {{"sampling_attr1", 123}, {"sampling_attr2", "string"}}))};
      |                                                                                ^
/home/runner/work/opentelemetry-cpp/opentelemetry-cpp/sdk/test/trace/tracer_test.cc:57:29: error: missing initializer for member ‘opentelemetry::v1::sdk::trace::SamplingResult::attributes’ [-Werror=missing-field-initializers]
   57 |       return {Decision::DROP};
      |                             ^
/home/runner/work/opentelemetry-cpp/opentelemetry-cpp/sdk/test/trace/tracer_test.cc:57:29: error: missing initializer for member ‘opentelemetry::v1::sdk::trace::SamplingResult::trace_state’ [-Werror=missing-field-initializers]
cc1plus: all warnings being treated as errors

Failure seen by CLang:

[  7%] Building CXX object api/test/context/CMakeFiles/runtime_context_test.dir/runtime_context_test.cc.o
In file included from /home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/test/context/runtime_context_test.cc:4:
In file included from /home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/include/opentelemetry/context/runtime_context.h:7:
In file included from /home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/include/opentelemetry/context/context.h:7:
In file included from /home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/include/opentelemetry/context/context_value.h:8:
In file included from /home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/include/opentelemetry/baggage/baggage.h:8:
In file included from /home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/include/opentelemetry/common/kv_properties.h:6:
In file included from /home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/include/opentelemetry/common/key_value_iterable_view.h:10:
In file included from /home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/include/opentelemetry/common/key_value_iterable.h:6:
In file included from /home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/include/opentelemetry/common/attribute_value.h:10:
In file included from /home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/include/opentelemetry/nostd/variant.h:52:
In file included from /home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/include/opentelemetry/nostd/./internal/absl/types/variant.h:79:
In file included from /home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/include/opentelemetry/nostd/./internal/absl/types/../types/internal/variant.h:37:
/home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/include/opentelemetry/nostd/./internal/absl/types/../types/internal/../../types/bad_variant_access.h:78:2: error: extra ';' outside of a function is incompatible with C++98 [-Werror,-Wc++98-compat-extra-semi]
};
 ^
In file included from /home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/test/context/runtime_context_test.cc:4:
In file included from /home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/include/opentelemetry/context/runtime_context.h:7:
In file included from /home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/include/opentelemetry/context/context.h:7:
In file included from /home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/include/opentelemetry/context/context_value.h:8:
In file included from /home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/include/opentelemetry/baggage/baggage.h:8:
/home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/include/opentelemetry/common/kv_properties.h:273:28: error: no newline at end of file [-Werror,-Wnewline-eof]
OPENTELEMETRY_END_NAMESPACE
                           ^
In file included from /home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/test/context/runtime_context_test.cc:4:
In file included from /home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/include/opentelemetry/context/runtime_context.h:7:
In file included from /home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/include/opentelemetry/context/context.h:7:
In file included from /home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/include/opentelemetry/context/context_value.h:13:
In file included from /home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/include/opentelemetry/trace/span.h:17:
/home/runner/work/opentelemetry-cpp/opentelemetry-cpp/api/include/opentelemetry/trace/span_metadata.h:43:28: error: no newline at end of file [-Werror,-Wnewline-eof]
OPENTELEMETRY_END_NAMESPACE
                           ^
3 errors generated.

This PR is ready for review.

Once more warnings are reported by the build, subsequent warning cleanups PR can be filed to fix the issues found, like #1649

Note that the new builds are not required to pass, so this will not block any work.

[marcalff]

Setting to draft:

Using this branch to check existing warnings,
and pushing fixes independently.

Once the main branch is clean, this can be then merged to main.

[marcalff]

Status:

As of 2022-10-10, remaining issues count is:

• 66 errors with gcc
• 19 errors with clang
• 21 errors with msvc

[marcalff]

Status:

As of 2022-10-12:

• gcc build is clean
• clang build is clean
• 4 errors remaining with msvc

[owent]

LGTM

[lalitb]

LGTM. Thanks.

[esigo]

LGTM
Thanks for the PR :)

[marcalff]

Thanks all for the review.

Ready to merge.