Process precompiled and ldflags properties of library.properties

[maxgerhardt]

What kind of issue is this?

• [X ] Feature Request.
  Start by telling us what problem you’re trying to solve. Often a solution
  already exists! Don’t send pull requests to implement new features without first getting our
  support. Sometimes we leave features out on purpose to keep the project small.

---

Configuration

Operating system: Windows 10 x64

PlatformIO Version (platformio --version): PlatformIO Core, version 5.2.0a6

Description of problem

When using an Arduino library which makes use of a precompiled library, PlatformIO cannot compile them correctly without additional build_flags configuration, which is not needed for the Arduino IDE.

Refer e.g. https://community.platformio.org/t/how-to-debug-collect2-link-error-in-arduino-mkriotcarrier-example-sketch/22310 in which the library https://github.com/arduino-libraries/Arduino_MCHPTouch is used. This library contains in the library.properties

precompiled=true
ldflags=-lsamd21_qt_gcc

and the library file.

However, just using this library with

lib_deps =
     arduino-libraries/Arduino_MCHPTouch @ ^1.1.0

fails as PlatformIO does not process these flags.

Steps to Reproduce

1. Create a new project for mkrwifi1010
2. Add the Arduino_MCHPTouch via lib_deps
3. Use example sketch as src\main.cpp
4. Compile

Actual Results

Linking .pio\build\mkrwifi1010\firmware.elf
.pio\build\mkrwifi1010\lib29e\libArduino_MCHPTouch.a(touch.c.o): In function `touch_sensors_init':
touch.c:(.text.touch_sensors_init+0x12): undefined reference to `touch_selfcap_sensors_init_with_rs_table'
touch.c:(.text.touch_sensors_init+0x38): undefined reference to `touch_selfcap_sensor_config'
touch.c:(.text.touch_sensors_init+0x56): undefined reference to `touch_selfcap_sensor_config'
touch.c:(.text.touch_sensors_init+0x74): undefined reference to `touch_selfcap_sensor_config'
touch.c:(.text.touch_sensors_init+0x92): undefined reference to `touch_selfcap_sensor_config'
touch.c:(.text.touch_sensors_init+0xb0): undefined reference to `touch_selfcap_sensor_config'
touch.c:(.text.touch_sensors_init+0xbc): undefined reference to `touch_selfcap_sensors_calibrate'
.pio\build\mkrwifi1010\lib29e\libArduino_MCHPTouch.a(touch.c.o): In function `touch_sensors_measure':
touch.c:(.text.touch_sensors_measure+0x16): undefined reference to `touch_selfcap_sensors_measure'
collect2.exe: error: ld returned 1 exit status
*** [.pio\build\mkrwifi1010\firmware.elf] Error 1
=========== [FAILED] Took 4.18 seconds ===========

Expected Results

Successful compilation.

If problems with PlatformIO Build System:

The content of platformio.ini:

[env:mkrwifi1010]
platform = atmelsam
board = mkrwifi1010
framework = arduino
lib_deps =
     arduino-libraries/Arduino_MCHPTouch @ ^1.1.0

Source file to reproduce issue:

#include "Arduino_MCHPTouch.h"

void setup()
{
  Serial.begin(9600);
  while (!Serial)
    ;
  // QTouch initialization
  if (!TOUCH.begin())
  {
    Serial.println("Error in sensors initialization!");
    while (1)
      ;
  }
  Serial.println("Touch initialization Done!");
}

void loop()
{
  // polling the sensor for new data
  TOUCH.poll();

  // Checks if new data are available
  if (TOUCH.available())
  {
    //reads senseors
    Serial.print("Sensor 1 status: ");
    Serial.println(TOUCH.read(0));
    Serial.print("Sensor 2 status: ");
    Serial.println(TOUCH.read(1));
    Serial.print("Sensor 3 status: ");
    Serial.println(TOUCH.read(2));
    Serial.print("Sensor 4 status: ");
    Serial.println(TOUCH.read(3));
    Serial.print("Sensor 5 status: ");
    Serial.println(TOUCH.read(4));
    Serial.println();
  }
  delay(100);
}

Additional info

After adding

build_flags =
    -L"$PROJECT_LIBDEPS_DIR/$PIOENV/Arduino_MCHPTouch/src/cortex-m0plus"
    -lsamd21_qt_gcc 

compilation is successful.

Linking .pio\build\mkrwifi1010\firmware.elf
Checking size .pio\build\mkrwifi1010\firmware.elf
Advanced Memory Usage is available via "PlatformIO Home > Project Inspect"
RAM:   [=         ]   8.6% (used 2816 bytes from 32768 bytes)
Flash: [=         ]   8.2% (used 21564 bytes from 262144 bytes)
Building .pio\build\mkrwifi1010\firmware.bin
=========== [SUCCESS] Took 2.92 seconds ===========

[maxgerhardt]

Implementing this would also make many library.json and extra scripts unnecessary, as e.g. used in https://github.com/BoschSensortec/BSEC-Arduino-library. Note that the Arduino IDE seems to use src/<CPU architecture> as the linker path directory.