Eclipse with cmake4eclipse: Editor does not recognize symbols defined in CMakeLists.txt

Question

Windows 10 Version 1809
Eclipse IDE for C/C++ Developers (Version: 2019-06 (4.12.0))
cmake4eclipse 2.1.1
cmake version 3.17.0
GNU Make 4.2.1

repository for a simple example project: https://bitbucket.org/ChristianW/cmake_driven_example_arm-none-eabi-gcc/src/master/

When using the arm-none-eabi-gcc compiler, the Eclipse C/C++ Editor does not recognize my symbols set in the CMakeLists.txt.

...
if(1)
 set(CMAKE_C_COMPILER arm-none-eabi-gcc)
else()
 set(CMAKE_C_COMPILER gcc)
endif()
...

When using the gcc compiler, the Eclipse C/C++ Editor does recognize my symbols set in the CMakeLists.txt.

...
if(0)
 set(CMAKE_C_COMPILER arm-none-eabi-gcc)
else()
 set(CMAKE_C_COMPILER gcc)
endif()
...

In both cases building the project is working. Any ideas what's the problem here?

Kind regards, Christian

Edit: content of CMakeLists.txt

cmake_minimum_required(VERSION 3.10)

#set(CMAKE_MAKE_PROGRAM "C:/Program Files/mingw-w64/x86_64-8.1.0-posix-seh-rt_v6-rev0/mingw64/bin/mingw32-make.exe")
set(CMAKE_MAKE_PROGRAM "C:/Program Files (x86)/mingw-w64/i686-8.1.0-posix-dwarf-rt_v6-rev0/mingw32/bin/mingw32-make.exe")
#set(CMAKE_MAKE_PROGRAM "C:/Tools/ON Semiconductor/RSL10_IDE_3_3/IDE_V3.2.2.13/arm_tools/bin/make.exe")

set(CMAKE_SYSTEM_NAME Generic)
set(CMAKE_SYSTEM_PROCESSOR arm)
set(CMAKE_CROSSCOMPILING 1)

set(CMAKE_TRY_COMPILE_TARGET_TYPE "STATIC_LIBRARY")
set(CMAKE_C_OBJCOPY arm-none-eabi-objcopy)

if(1)
    set(CMAKE_C_COMPILER arm-none-eabi-gcc)
else()
    set(CMAKE_C_COMPILER gcc)
endif()

project(cmake_driven_example_arm-none-eabi-gcc C)

set(SOURCES
    main.c
    modules/math/math.c
)

include_directories(
    modules/math
)

set(CMAKE_C_FLAGS "-DINCLUDE_MATH")
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DMYVAR=5")

# Invoking: Cross ARM C Linker
set(CMAKE_EXE_LINKER_FLAGS "-Xlinker --gc-sections")
set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -T\"${CMAKE_SOURCE_DIR}/sdk_packages/rsl10_sdk/source/firmware/cmsis/source/GCC/sections_modified.ld\"")


# build elf file
add_executable(${PROJECT_NAME} ${SOURCES})
target_link_libraries(${PROJECT_NAME}
                        ${CMAKE_SOURCE_DIR}/sdk_packages/rsl10_sdk/lib/ble_core/Release/libblelib.a
                        ${CMAKE_SOURCE_DIR}/sdk_packages/rsl10_sdk/lib/ble_core/Release/libkelib.a
)

related cmake4eclipse topic

You forgot to add `CMakeLists.txt` into the question post. That script is important for the question, since exactly it adds `INCLUDE_MATH` and `MYVAR` macros. (And exactly this script in your case sets the compiler, which is normally avoided in CMake projects). — Tsyvarev, Jul 07 '20 at 07:38
I added the content of the CMakeLists.txt. for simplification I set the compiler in the CMakeLists.txt. But actually I don't know why this should be avoided (we are only using one toolchain to build the firmware)? — Guti_Haz, Jul 07 '20 at 09:35
Setting the compiler inside `CMakeLists.txt` won't work with [try_compile](https://cmake.org/cmake/help/v3.9/command/try_compile.html#try-compiling-source-files) command when it compiles given source files. This compilation is performed using auto-generated CMake project which knows nothing about your compiler setting. But `try_compile` correctly works with a **toolchain**, which path is contained in `CMAKE_TOOLCHAIN_FILE` variable: this variable is passed to the auto-generated project automatically. There are several widely used modules based on `try_compile`, e.g `CheckSymbolExists`. — Tsyvarev, Jul 07 '20 at 14:55
Note, that you may set the variable `CMAKE_TOOLCHAIN_FILE` even in the `CMakeLists.txt` script (before the `project()` call). This way you would use all advantages of the toolchain mechanism but doesn't require to specify the toolchain explicitely to `cmake` call. — Tsyvarev, Jul 07 '20 at 15:01

Guti_Haz · Accepted Answer · 2020-07-09T11:56:26.903

The indexer was set to "Use a fixed build configuration". That's why I could build in different configurations, but the Editor always showed the flag values of my specified configuration (=Debug).

It should be possible to use project specific (PS) indexer settings, but...

There is a bug within Eclipse which leads to an unintuitive behaviour of the indexer (see bug205299):

WS: Window > Preferences > C/C++ > Indexer > Build configuration for the indexer: Use the build configuration specified in the projects's indexer settings

PS: Project Properties > C/C++ General > Indexer > User active build configuration

Solution: Use workspace specific (WS) indexer settings: Use active build configuration

Maybe there was also a problem caused by the path to the compiler: "...\IDE_V3.2.2.13\arm_tools\bin\arm-none-eabi-gcc.exe" -> dots in the folder name IDE_V3.2.2.13

It gave me these warnings: (fyi: in the sample project I have not defined the entry symbol Reset_Handler)

With moving arm_tools folder, the Eclipse Editor recognized the symbols.

Eclipse with cmake4eclipse: Editor does not recognize symbols defined in CMakeLists.txt

1 Answers1