We're using MPC (Makefile, Project, and Workspace Creator) in ACE project and would like to specify different compilers (eg, for cross-compiling to different CPU or embedded, etc)
However, the Makefile always gets plain g++ set in the macro file:
#----------------------------------------------------------------------------
# Macros
#----------------------------------------------------------------------------
CXX = g++
How can we specify the compiler suite to use within the workspace (mwc), the base project (mpb), or the project file(s) (mpc) themselves?
The command line to run is:
mwc.pl -type make -include include /src/corba -relative PRJROOT=./ -expand_vars -value_template optimize=$buildOption -value_template obj_dir=obj/ $mwcFile
Thanks
Related
I have a CortexM0 project using a custom Makefile that builds and debugs successfully on a 1st machine.
Now trying to move the project to a second Mac.
Same version of Eclipse.
On build I get a linker error:
EclipseApr2019/gcc-arm-none-eabi-5_2-2015q4/bin/../lib/gcc/arm-none-eabi/5.2.1/../../../../arm-none-eabi/bin/ld: cannot find -lg
My make file looks like this (extract):
# echo "path="$(TOOLS)
$(TOOLS)arm-none-eabi-gcc -n -v -mcpu=cortex-m0 -mthumb -g -nostartfiles -T STM32F031C6_simple.ld main.c StartUp_simple.s -o $(NAME).elf
I have tried to append the ARM gcc tools directory to the PATH variable in the Project, but no luck.
I would add a -l option to the link stage in the makefile, but do not know why this library is being pulled in or where it is. My code only does a series of shifts and reads/writes to registers on an MCU. The build on the 1st machine worked fine without specifying a library location like this.
Given I have custom makefile and am not generating Makefile automatically, there are no tool settings (and Library search path) available under Properties/CC++Build/Settings.
What is library "g" that the linker is pulling in?
Where is it?
Under Eclipse, how can I point the linker to the library?
Why didn't I need to do that before?
What is some general advice for designing an Eclipse project with a custom makefile to make it most portable between machines?
Thank you.
Eclipse IDE for C/C++ Developers
Version: 2019-03 (4.11.0)
I try to use the c++ language bindings for the ev3dev lego brick: https://github.com/ddemidov/ev3dev-lang-cpp
The instruction is as follows:
mkdir build
cd build
cmake .. -DEV3DEV_PLATFORM=EV3
make
I am running windows and have cmake and mingw available. After running cmake it creates some files in the build directory. However: There is no makefile which could be picked of by make. So I am wondering how iam supposed to compile these bindings
On Windows, CMake generates a MSVC solution by default. Check for a .sln file in your build directory.
The instructions you linked are assuming a Unix-ish platform, where the default is to create Makefiles.
If you actually want Makefiles on Windows, add -G "Unix Makefiles" to the cmake line.
If you want to use MSVC as compiler but work on the command line, another option is -G "NMake Makefiles", and calling nmake after that.
Make sure to delete your build directory before trying to build a new generator target. CMake can be touchy about that.
Check cmake --help for a list of available options. (Especially the generator targets are platform-specific.)
I have a demo project and it's structure like as below:
top_dir
CMakeLists.txt
sub_dir1
CMakeLists.txt
sub_dir2
CMakeLists.txt
top_dir/sub_dir1/CMakeLists.txt used to build lib1 by using add_library(lib1 ...),
top_dir/sub_dir2/CMakeLists.txt used to build exe1 with linking lib1 by target_link_library(exe1 lib1).
And the content of top_dir/CMakeLists.txt is as below:
add_subdirectory(sub_dir2)
add_subdirectory(sub_dir1)
Normally, when build target exe1, cmake will check dependency so lib1 will be built before building exe1. The problem is I am transfering an existed makefile project into CMake, and there are many gcc link options, like "whole-archive ... no-whole-archive, allow-mutiple-definition", if use like target_link_library(exe1 "-Wl, --whole-archive ../sub_dir1/liblib1.a --no-whole-archive")(The form like this, and this may not work, it just a e.g.), cmake seem don't built lib1 any more. Is there any way i can use target_link_library like target_link_library(exe1 "-Wl, --whole-archive ../sub_dir1/liblib1.a") and cmake link dependency checking still work, or other way i can transfer these gcc link options into cmake?
Arguments for target_link_libraries are going into the resulted command line in the same order they appears. Whenever target name is used as argument, path to target's output is used in resulted command line. So, you may use library target whenever you need path to that library in the command line:
target_link_libraries(exe1 -Wl,--whole-archive lib1 -Wl,--no-whole-archive)
Such a way a target-level dependency between executable exe1 and library lib1 is automatically deduced by CMake, as usual.
The next hack permits to locally define the flags to the library to which you want to apply the flags, without modifying all exe link flags :
add_library(lib1_internal STATIC lib1.cpp)
add_library(lib1 STATIC dummy.cpp) # dummy.cpp is an empty file
target_link_libraries(lib1 PRIVATE -Wl,--whole-archive lib1_internal -Wl,--no-whole-archive )
....
target_link_libraries(exe1 lib1)
I used to use Xcode to build and run C++ program.
I use command line to compile the same source code in my Xcode project.
Compiling a individual .cpp file is OK.
Compiling more complicated project(more than one file) is NOT OK.
I have tried gcc, g++, clang, clang++.
The main problem is undefined symbol.
Could you show how to compile complicated project (more than one file) by command line?
From your description, it sounds like you're not using the -c (compile, but don't link) flag. Steps to build your project:
Compile all of the source files:
c++ -c file1.cpp
c++ -c file2.cpp
c++ -c file3.cpp
Link your final executable:
c++ file1.o file2.o file3.o
You can use an optional -o flag to specify the output program name. It probably defaults to a.out.
It would be better to use some kind of build tool (like make, for example) to automate this process, or you'll find it to be very error prone.
I'm a learning c++ developer writing a game initially on the Mac platform using XCode, but now moving to cross platform by leveraging CMake. So far I can get it compiled on my ickle linux netbook and I'm putting together a dev environment on this machine for on the go coding. However I'm finding that gcc recompiles every file whenever I make a change. Clearly I need some additional configuration to the CMakeLists.txt . My current one is very simple. Like so;
cmake_minimum_required (VERSION 2.8)
set (source
Creature.cpp
DisplayManager.cpp
Engine.cpp
EngineState.cpp
Entity.cpp
GameWorld.cpp
GfxSFML.cpp
Item.cpp
Map.cpp
Position.cpp
Projectile.cpp
ScreenTile.cpp
SquadAI.cpp
Terrain.cpp
UIButton.cpp
UICharPanel.cpp
UIView.cpp
Utility.cpp
Weapon.cpp
fov.cpp
main.cpp
)
find_package (OpenAL)
find_package (OpenGL)
find_package (SFML)
set(CMAKE_CXX_FLAGS "-g -Wall -pg")
add_executable (tractionedge ${source})
target_link_libraries(tractionedge ${SFML_LIBRARY} ${OPENGL_LIBRARY} ${OPENAL_LIBRARY})
I've concentrated so far on C++ as a language rather than build systems by sticking with XCode for everything. My knowledge of Autotools (make?) and Gcc is very limited. How do I have gcc only recompile the changed source?
Are you rerunning cmake every time? If you just modify one source file, you should be able to simply rerun make, and it should rebuild just the one object file before linking. If you rerun cmake, it might mark all of the source files dirty and rebuild everything.
Only rerun cmake if you change the actual list of source files being used, or other major changes like that.
Rebuilding only the modified sources SHOULD be the default behavior. Of course if you change a central header included by nearly all dependent cpp files it'll trigger a nearly complete rebuild. Look at what happens if you only modify one cpp file (adding a comment or alike), if more than that compilation unit is compiling then I propose you to invest more time investigating it eventually giving you my EMail to have a deeper look at the configuration.
Another possibility is that you are compiling under windows and using a 2.8 cmake that has a bug regarding this. Look at a 2.9 version to see if that defect is away then: http://www.mail-archive.com/cmake#cmake.org/msg24876.html
I would rewrite your CMakeLists.txt using glob (maybe move the files in a "src" directory if you have other *.cpp files around) and give your project a name (this sets some important variables):
cmake_minimum_required (VERSION 2.8)
project(TRACTION)
file (GLOB TRACTION_SOURCES *.cpp)
find_package (OpenAL)
find_package (OpenGL)
find_package (SFML)
set(CMAKE_CXX_FLAGS "-g -Wall -pg")
add_executable (tractionedge ${TRACTION_SOURCES})
target_link_libraries(tractionedge ${SFML_LIBRARY} ${OPENGL_LIBRARY} ${OPENAL_LIBRARY})
I also experienced unnecessary rebuilds using cmake and visual studio. The problem is related to an inappropriate x64 configuration parameter: Visual Studio 2008 Unnecessary Project Building
A simple solution in many of these cases is to completely wipe the build tree and regenerate it (and I mean something along the lines of rm -rf build && mkdir build && cd build && cmake -G "Unix Makefiles" ../src, not just make clean)