used uninitialized [-Werror=uninitialized]

[sergey-safarov]

Title: var used uninitialized [-Werror=uninitialized]

Description:
I compile master (a7758b8) sources on CentOS 9 using the command

bazel build -c opt envoy --subcommands --jobs 1 --verbose_failures --sandbox_debug

And got error

    inlined from 'Envoy::UnionStringBase<Validator>::UnionStringBase() [with Validator = Envoy::Http::HeaderStringValidator]' at ./envoy/common/union_string.h:66:23,
    inlined from 'Envoy::Http::HeaderString::HeaderString(Envoy::UnionString&&)' at source/common/http/header_map_impl.cc:44:54:
external/com_google_absl/absl/container/internal/inlined_vector.h:522:5: error: '<unnamed>.absl::lts_20240722::InlinedVector<char, 128, std::allocator<char> >::storage_.absl::lts_20240722::inlined_vector_internal::Storage<char, 128, std::allocator<char> >::data_' is used uninitialized [-Werror=uninitialized]
  522 |     data_ = other_storage.data_;
      |     ^~~~~
In file included from ./envoy/http/header_map.h:14,
                 from ./source/common/http/header_map_impl.h:12,
                 from source/common/http/header_map_impl.cc:1:
./envoy/common/union_string.h: In constructor 'Envoy::Http::HeaderString::HeaderString(Envoy::UnionString&&)':
./envoy/common/union_string.h:66:31: note: '<anonymous>' declared here
   66 |   UnionStringBase() : buffer_(InlinedStringVector()) {
      |                               ^~~~~~~~~~~~~~~~~~~~~
In file included from external/com_google_absl/absl/container/inlined_vector.h:53,
                 from external/com_google_absl/absl/strings/cord.h:80,
                 from bazel-out/aarch64-opt/bin/external/com_google_protobuf/src/google/protobuf/io/_virtual_includes/io/google/protobuf/io/coded_stream.h:112,
                 from bazel-out/aarch64-opt/bin/external/envoy_api/envoy/config/core/v3/base.pb.h:20,
                 from ./source/common/http/header_map_impl.h:11,
                 from source/common/http/header_map_impl.cc:1:

Full error message

[wbpcode]

Basically, I will suggest you to use our build image and ci scripts to build the binary which would get better experience.

[sergey-safarov]

Just for your info.
This error is related to variable initialization and can be easily fixed in the source code.
As a workaround I used

--copt="-Wno-uninitialized" --cxxopt="-Wno-uninitialized"

This helps compile sources.
I think this needs to be reviewed by some devs to add variable initialization.

[github-actions]

This issue has been automatically marked as stale because it has not had activity in the last 30 days. It will be closed in the next 7 days unless it is tagged "help wanted" or "no stalebot" or other activity occurs. Thank you for your contributions.

[github-actions]

This issue has been automatically closed because it has not had activity in the last 37 days. If this issue is still valid, please ping a maintainer and ask them to label it as "help wanted" or "no stalebot". Thank you for your contributions.