使用g++编译含Google Test子模块程序时提示“g++ is not a full path”

Let's break down your problem and fix it step by step.

Core Cause of the Error #

The error "g++ is not a full path" pops up because CMake often requires an absolute path for the compiler executable when you set CMAKE_CXX_COMPILER directly in your CMakeLists.txt. Using just g++ might fail if CMake can't reliably resolve the full executable path from your system's environment variables.

Solution 1: Use an Absolute Path for g++ #

First, find the full path to your g++ executable. Run this in your terminal:

which g++

You'll get an output like /usr/bin/g++ (the path varies by system). Update your CMAKE_CXX_COMPILER line to use this absolute path:

set(CMAKE_CXX_COMPILER "/usr/bin/g++")

Solution 2: Let CMake Detect the Compiler (Recommended) #

You don't need to hardcode CMAKE_CXX_COMPILER in your CMakeLists.txt at all. CMake automatically detects available C++ compilers on your system. If you specifically want to use g++, specify it when running CMake instead:

cmake -DCMAKE_CXX_COMPILER=g++ ..

This avoids hardcoding paths that might differ across systems.

Fixing Other Issues in Your CMakeLists.txt #

Your current CMakeLists has a few other problems that will cause errors once you fix the compiler issue:

1. Incorrect add_subdirectory path: Since you added googletest as a submodule in your testgoogletest directory, the path should be googletest, not ../googletest.
2. Unfinished target_include_directories line: You need to specify your own test target and complete the include directory setup.
3. Better include directory handling: Linking against gtest/gmock targets automatically pulls in their header directories, so you don't need to set them manually.

Here's a corrected, complete CMakeLists.txt example for your project:

cmake_minimum_required(VERSION 3.5.1)
project(try_googletest)

# Optional: Auto-find g++ path to avoid hardcoding
find_program(GPP_EXECUTABLE g++)
if(GPP_EXECUTABLE)
    set(CMAKE_CXX_COMPILER ${GPP_EXECUTABLE})
endif()

# Add the googletest submodule with correct path
add_subdirectory(googletest gtest_build)

# Create your test executable (replace test_main.cpp with your actual test file)
add_executable(my_tests test_main.cpp)

# Link against gtest/gmock - this auto-includes their header directories
target_link_libraries(my_tests gtest gmock_main)

# Optional: Enforce C++ standard (adjust version as needed)
target_compile_features(my_tests PRIVATE cxx_std_17)

Final Build Steps #

Once your CMakeLists.txt is fixed, run these commands to build your project:

mkdir build
cd build
cmake ..
make

内容的提问来源于stack exchange，提问作者Codoscope