[Bug] MessageTest fails to build with GCC 15.3.0 and 16.2.1 (-Werror=stringop-truncation)

Abierto
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#621 0 comentarios 0 reacciones 0 asignados Ver en GitHub

@davlgd ya está trabajando en esto.

Desde el 31/10/2026.

  • #622 de @davlgd — abierto

Evaluación

Dificultad
1/5
Tiempo estimado
Menos de una hora
Aptitud para principiantes
25/100
Tipo de issue
Error
Claridad
Bien especificado
Estado de actividad
Estancado
Stack tecnológico
cmake, cpp
Área
testing

Línea de trabajo

The warning comes from testAllocatedContents in tests/MessageTest.cc around line 53, where strncpy copies str.length() bytes. Check the setAllocatedContent() call and the msg.getLength() comparison that follow. A linked pull request (#622) is already open against this issue, so review that first. Done means the MessageTest.* tests build under the top-level -Werror and pass.

Escrito por el modelo de indexación a partir del texto del issue.

Descripción

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Version

pulsar-client-cpp 4.2.0 on Exherbo Linux (x86_64), built with GCC 15.3.0, -O2 and -DBUILD_TESTS=ON. Also reproduced on Arch Linux with GCC 16.2.1 and protobuf 36.1; there, the build used -Wno-error=unused-result to get past a separate protobuf build failure, with -Werror=stringop-truncation still enabled. The same call is present on main at f71d7e99019d58b1d11858f05ff0dc83b718627b (source inspection).

Minimal reproduce step

With the dependencies installed and GCC 15.3.0:

cmake -S . -B build -DBUILD_TESTS=ON -DCMAKE_CXX_FLAGS=-O2
cmake --build build

On Arch Linux (GCC 16.2.1, protobuf 36.1):

cmake -S . -B build-arch -DBUILD_TESTS=ON "-DCMAKE_CXX_FLAGS=-O2 -Wno-error=unused-result" -DCMAKE_C_FLAGS=-O2
cmake --build build-arch --target pulsar-tests

The top-level CMakeLists.txt adds -Werror, so tests/MessageTest.cc fails to compile. Failing build log: https://gitlab.exherbo.org/davlgd/CleverCloud/-/jobs/223191

What did you expect to see?

The tests build.

What did you see instead?
tests/MessageTest.cc:53:12: error: 'char* strncpy(char*, const char*, size_t)' output truncated before terminating nul copying 7 bytes from a string of the same length [-Werror=stringop-truncation]
   53 |     strncpy(content, str.c_str(), str.length());
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1plus: all warnings being treated as errors
Anything else?

testAllocatedContents copies str.length() bytes with strncpy, so the terminating NUL is never written. No NUL terminator is required in this test: setAllocatedContent() takes a pointer and an explicit byte count, and the comparison is bounded by msg.getLength(). GCC's documentation uses this strncpy(d, s, strlen(s)) pattern as its example for this warning and suggests memcpy instead. With strncpy replaced by memcpy for the same byte count, all 10 MessageTest.* tests passed on Arch Linux with GCC 16.2.1 and -O2 -Wno-error=unused-result.

Are you willing to submit a PR?
  • I'm willing to submit a PR!
Lenguaje dominante
C++
Estrellas
72
Forks
93
Sin PR fusionados en 30 d

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