[Bug]: cmake configuration broken for compilers without C++14

[Sickeroni]

Describe the issue

prologue: yes this sounds strange at first, since C++14 is the minimum for the project. But here are the details.

description: GTEST needs minimum C++14 to be compiled It can therefore be also compiled with C++14 or higher. higher also means C++17. proof of packages in C++17 @ conancenter As a result if your compiler supports C++17 gtest should be in theory usable.

There are some more special compilers out there not supporting C++14, but C++17. (one example is IAR) when configuring cmake with such a compiler we fail. (configure step of cmake! not build step!)

technical details: in the file googletest/googletest/cmake/internal_utils.cmake in line 198 there is following line of code

target_compile_features(${name} PUBLIC cxx_std_14)

This sets a requirement, that the compiler, used for the specified files, supports specific compiler features. CMake Docu Link cxx_std_14 means the compiler supports C++14. That's true for most compilers using C++17 (gcc, clang etc) but not for all. cxx_std_17 can also be enough for C++17 compiles. CMake Docu Link

possible solutions

1. Move the check to another place
2. specify feature based on CXX_STANDARD CMake Docu Link
3. remove this check

Steps to reproduce the problem

cmake-configure gtest with iar (or any other compiler supporting cxx_std_17, but not cxx_std_14)

What version of GoogleTest are you using?

1.15.0

What operating system and version are you using?

• ubuntu 24.04.1
• ubuntu 24.04 in docker

What compiler and version are you using?

IAR

What build system are you using?

CMake

Additional context

details on IAR CMake Module cxx_std_17 is set by the IAR CMake module

CMake Documentation The Documentation on the flags is a bit ambiguous. LINK

The following meta features indicate general support for the associated language standard. It reflects the language support claimed by the compiler, [...]

My interpretation: if feature is set, we support this explicit standard, here C++14

cxx_std_14 Compiler mode is at least C++ 14.

What does "at least" mean here?

• till C++14?
• C++14 and higher?
• C++14 and maybe others, based on other featureflags?

the last interpretation makes the most sense to me. But can still be misunderstanded.