pe32dht22_pub

This still needs some documentation.

What is documented however, is the automatic build_version.h updates.

Auto updating build_version.h

Find platform.txt and edit platform.local.txt:

$ find ~/Jailed/arduino/ -name platform.txt -o -name 'platform.local.txt'
/home/walter/Jailed/arduino/.arduino15/packages/esp32/hardware/esp32/2.0.5/platform.local.txt
/home/walter/Jailed/arduino/.arduino15/packages/esp32/hardware/esp32/2.0.5/platform.txt
/home/walter/Jailed/arduino/.arduino15/packages/arduino/hardware/avr/1.8.6/platform.txt

$ cat >>/home/walter/Jailed/arduino/.arduino15/packages/esp32/hardware/esp32/2.0.5/platform.local.txt <<EOF
recipe.hooks.sketch.prebuild.1.pattern=/usr/local/bin/exec-build-version-h-for-arduino-ide "{build.source.path}/build_version.h" "{build.path}/sketch/build_version.h"
EOF

Add the following file with execute permissions as /usr/local/bin/exec-build-version-h-for-arduino-ide:

#!/bin/sh

# Setup, in platform.[local.]txt you add this:
# recipe.hooks.sketch.prebuild.1.pattern=/usr/local/bin/exec-build-version-h-for-arduino-ide "{build.source.path}/build_version.h" "{build.path}/sketch/build_version.h"

first_line=$(head -n1 "$1" 2>/dev/null)
if test "$first_line" != "/*#!/usr/local/bin/exec-build-version-h-for-arduino-ide 2>/dev/null"; then
    echo "$0: first line of '$1' is not '/*#!/usr/local/bin/exec-build-version-h-for-arduino-ide 2>/dev/null'" >&2
    echo "$0: skipping..." >&2
    exit 0
fi

# Check whitelist so that we do not run random stuff from the internet.
# (Double check config path if you're (fire)jailing this into a private dir.)
if ! grep -qxF "$1" "$HOME/.config/arduino-ide/exec-build-version-h.whitelist"; then
    echo "$0: '$1' not in ~/.config/arduino-ide/exec-build-version-h.whitelist" >&2
    echo "$0: not executing..." >&2
    exit 0
fi

# Jump to source directory so git can be run.
cd "$(dirname "$1")"

# Run it (and write to $2).
if test -n "$2"; then
    # Write to file {build.path}/sketch/build_version.h
    /bin/sh "$1" >"$2.tmp" && mv "$2.tmp" "$2"
    sed -e 's@^@(debug) exec-build-version-h-for-arduino-ide: @' "$2" >&2
else
    # Simply dump to stdout.
    /bin/sh "$1"
fi

Restart Arduino IDE for the platform.local.txt changes to take effect.

Changing build_version.h

A skeleton build_version.h looks like this:

/*#!/usr/local/bin/exec-build-version-h-for-arduino-ide 2>/dev/null
... shell script here ...
#(header, do not touch next two lines)
cat <</*
//*/
... header file here ...
/*
#(trailer, do not touch this and previous line)*/

For the shell script, we can add:

GIT_VERSION=$(git describe --tags --dirty --always)

For the header file, we can add:

#define GIT_VERSION "$GIT_VERSION"

When asking the Arduino IDE to compile, it will run /usr/local/bin/exec-build-version-h-for-arduino-ide on the build_version.h. If this fails, then original build_version.h which is legal C is used. If it succeeds, the output is written to a temporary build_version.h in the compilation directory.

Build output then shows:

(debug) exec-build-version-h-for-arduino-ide: //*/
(debug) exec-build-version-h-for-arduino-ide: #define GIT_VERSION "b9e7973-dirty"

And GIT_VERSION can be used as a regular macro.

wdoekes/pe32dht22_pub

pe32dht22_pub

Auto updating build_version.h

Changing build_version.h