Compiler options in arduino-cli

Development Tools Arduino Command Line Tools
1

Hi there,

Please excuse me if this question has been answered before. I have been looking for a way to specify project specific compiler options. I have read the threads where hardware.local.txt and boards.local.txt are discussed, but if I understand correctly, these are all global settings.

As an example, I have a project that needs the following to compile.

arduino-cli compile --build-property compiler.cpp.extra_flags=-fexceptions

It would be nice if the compiler.cpp.extra_flags=-fexceptions settings could be put in a project specific file like sketch.json.

With kind regards,
Jeroen.

2

There is talk about adding this sort of capability to Arduino CLI, but it is only in the planning stage at this point.

For now, I think your best solution would be to add a build script (or makefile or whatever you like) to the sketch that contains the necessary arduino-cli compile command. That way you don't need to bother with manually adding the right build flags every time you want to compile.

3

Thank you for the information, I thought about adding a Makefile too, but it is good to hear that I did not miss something obvious.

4

In case anyone has the same question, I include a reasonably generic Makefile for future reference.

FQBN := arduino:avr:pro
PORT := /dev/ttyUSB0
BUILD := build
FLAGS :=

ARDUINO := arduino-cli

SKETCH := $(wildcard *.ino)
LIBS := $(wildcard *.cpp *.h *.tcc)
HEX := $(BUILD)/$(subst :,.,$(FQBN))/$(addsuffix .hex, $(SKETCH))


all: $(HEX)

$(HEX): $(SKETCH) $(LIBS)
        $(ARDUINO) compile -b $(FQBN) \
    --build-property compiler.cpp.extra_flags="$(FLAGS)" -e

upload: $(HEX)
        $(ARDUINO) upload -b $(FQBN) -p $(PORT) -i $(HEX)