Add current sketch dir to include path when compile library

[sadr0b0t]

Hello,

I am writing a library for Arduino and I want to make it configurable at compile time with some defines in include file.

1. Create library with module.h and module.cpp inside.
2. Add #include"module_config.h" to my library module.cpp file (module_config.h file does not exist library dir)
3. Create sketch using the library with #include"module.h".
4. Create additional module_config.h file in sketch dir and put some defines inside.
5. Try to compile the sketch and receive module_config.h not found compilation error from library files.

So I open
~/.arduino15/packages/arduino/hardware/avr/1.6.13/platform.txt

file and add -I{build.path}/sketch C++ compile option:

Compile c++ files

recipe.cpp.o.pattern="{compiler.path}{compiler.cpp.cmd}" {compiler.cpp.flags} -mmcu={build.mcu} -DF_CPU={build.f_cpu} -DARDUINO={runtime.ide.version} -DARDUINO_{build.board} -DARDUINO_ARCH_{build.arch} {compiler.cpp.extra_flags} {build.extra_flags} -I{build.path}/sketch {includes} "{source_file}" -o "{object_file}"

At this time all compiles just fine.

I have taken this option from ChipKIT platform.txt, by the way:
http://chipkit.net/wiki/index.php?title=ChipKIT_core

[ReeceWeb]

+1

This is a really important feature for library developers, since it allows compile-time optimizations based on conditional compilation without requiring the user to edit files in the library.

The include path search order should be: first the sketch dir, and then fall back to the library. This lets a library developer deliver a default version of the header inside the library. It would be used if the sketch does not provide one, and has the secondary advantage of serving as a template.

To make this more formal, perhaps introduce a new file extension like ".cfg" or ".libcfg"? Having a different extension allows the nice convention that if "libname.h" is the main include file for the library, then "libname.cfg" is the config file that goes with it. For bonus points, "Sketch->Include Library" could copy the "libname.cfg" from the requested library into the sketch to seamlessly provide a template ready for the user to edit.

[per1234]

+1

Closing as duplicate of #2547, which was in turn closed as a duplicate of the similar arduino/arduino-builder#15.