Treatment of multi-file sketches not match Arduino build process

[twpayne]

Background: I'm porting an existing multi-file Arduino sketch to PlatformIO. It does not currently work because PlatformIO's conversion of multi-file sketches to C++ is different to the Arduino IDE's.

The Arduino IDE's process is described in the Arduino Build Process, section "Multi-file sketches" and "Transformations to the main sketch file".

PlatformIO's conversion is in ConvertInoToCpp.

Notable differences are:

• Arduino creates a single output source file containing all input .ino files, whereas PlatformIO creates one per .ino file.
• Arduino inserts forward function declarations into the single resulting sketch file, whereas PlatformIO only inserts per-file forward function declarations in each file.

Would you like a patch to change PlatformIO's behaviour to more closely match Arduino's?

[ivankravets]

Could you provide me an example which works in Arduino IDE, but doesn't work in PlatformIO?

[twpayne]

Here's a short example that demonstrates a difference. There are two source files:

src/Blink.io

void blink() {
  digitalWrite(led, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);               // wait for a second
  digitalWrite(led, LOW);    // turn the LED off by making the voltage LOW
  delay(1000);               // wait for a second
}

src/PlatformIO_example.ino

/*
  Blink
  Turns on an LED on for one second, then off for one second, repeatedly.

  This example code is in the public domain.
 */

// Pin 13 has an LED connected on most Arduino boards.
// Pin 11 has the LED on Teensy 2.0
// Pin 6  has the LED on Teensy++ 2.0
// Pin 13 has the LED on Teensy 3.0
// give it a name:
int led = 13;

// the setup routine runs once when you press reset:
void setup() {
  // initialize the digital pin as an output.
  pinMode(led, OUTPUT);
}

// the loop routine runs over and over again forever:
void loop() {
  blink();
}

The Arduino compiles and builds this just fine, but PlatformIO gives an error:

$ platformio run
[Sat Mar 21 15:58:51 2015] Processing autogen_megaADK (platform: atmelavr, board: megaADK, framework: arduino)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
avr-g++ -o .pioenvs/autogen_megaADK/src/Blink.o -c -fno-exceptions -fno-threadsafe-statics -g -Os -Wall -ffunction-sections -fdata-sections -MMD -mmcu=atmega2560 -DF_CPU=16000000L -DARDUINO_ARCH_AVR -DARDUINO_AVR_ADK -DARDUINO=10601 -DPLATFORMIO=010200 -I.pioenvs/autogen_megaADK/FrameworkArduino -I.pioenvs/autogen_megaADK/FrameworkArduinoVariant .pioenvs/autogen_megaADK/src/Blink.cpp
Blink.ino: In function 'void blink()':
Blink.ino:2:16: error: 'led' was not declared in this scope
scons: *** [.pioenvs/autogen_megaADK/src/Blink.o] Error 1
=========================================================================================================================== [ ERROR ] Took 0.54 seconds ===========================================================================================================================

The problem here is PlatformIO compiles src/Blink.ino on its own, which does not include a declaration of the variable led. The Arduino concatenates all the *.ino files together so the declaration for led appears in the same file as its use in the blink() function.

I'm not suggesting for a moment that this is a nice way to organise code, but I suspect that people would expect PlatformIO to behave the same way as the Arduino IDE.

Do tell me if you need any more info. I'm working on a very rough prototype to emulate the Arduino IDE's concatenation step at the moment.

[ivankravets]

Thanks, I got you. I will resolve this issue today and ask you to test!

[twpayne]

Thanks! Here's the rough-and-ready standalone script that seems to Do The Right Thing(tm):
https://gist.github.com/twpayne/bdea90725d3d9b6bba1c

[ivankravets]

Tom, thanks for your script. However, this issue is more interesting:

• need to detect which *.ino/pde candidate to be nominated as "main"
• need to specify preprocessor with correct lines for multi-sketches. Warnings/Errors should be reported with correct lines from original sketches ,even when they are merged into single piomain.cpp.

See how I've fixed it 7f43df4

---

Could I ask you to test it using PlatformIO Development version?

[glynhudson]

Nice work guys. I'm running latest V2.9.4, should this fix be included?

I'm trying to migrate an existing project with multiple .ino files to platformio:
https://github.com/openenergymonitor/emonpi/tree/master/firmware/firmware

There are 6 files, I have renamed firmware.ino to main.ino to help to the platoformio compiler. however I am getting 'not defined' errors:

e.g. emonPi_startup function cannot be found which is in startup.ino.

These files compile fine with Arduino IDE 1.6.8. What can I do to make these files compile on platfomio? I would very much like to switch to using platormio, it's super nice. Good work 👍

~/Downloads/dev/platformio_test$ platformio run
[Tue Jun  7 13:37:33 2016] Processing uno (platform: atmelavr, board: uno, framework: arduino)
--------------------------------------------------------------------------------------------------------------------------------------------
avr-g++ -o .pioenvs/uno/src/tmp_ino_to.o -c -fno-exceptions -fno-threadsafe-statics -std=gnu++11 -g -Os -Wall -ffunction-sections -fdata-sections -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO_ARCH_AVR -DARDUINO_AVR_UNO -DARDUINO=10608 -DPLATFORMIO=020904 -I.pioenvs/uno/FrameworkArduino -I.pioenvs/uno/FrameworkArduinoVariant -I.pioenvs/uno/JeeLib_ID252 -I.pioenvs/uno/EmonLib_ID116 -I.pioenvs/uno/OneWire_ID1 -I.pioenvs/uno/DallasTemperature_ID54 -I.pioenvs/uno/Wire -I.pioenvs/uno/Wire/utility -I.pioenvs/uno/LiquidCrystal_I2C_ID576 -Isrc src/tmp_ino_to.cpp
avr-ar rcs .pioenvs/uno/libFrameworkArduinoVariant.a
avr-ranlib .pioenvs/uno/libFrameworkArduinoVariant.a
avr-g++ -o .pioenvs/uno/FrameworkArduino/CDC.o -c -fno-exceptions -fno-threadsafe-statics -std=gnu++11 -g -Os -Wall -ffunction-sections -fdata-sections -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO_ARCH_AVR -DARDUINO_AVR_UNO -DARDUINO=10608 -I.pioenvs/uno/FrameworkArduino -I.pioenvs/uno/FrameworkArduinoVariant .pioenvs/uno/FrameworkArduino/CDC.cpp
avr-g++ -o .pioenvs/uno/FrameworkArduino/HardwareSerial.o -c -fno-exceptions -fno-threadsafe-statics -std=gnu++11 -g -Os -Wall -ffunction-sections -fdata-sections -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO_ARCH_AVR -DARDUINO_AVR_UNO -DARDUINO=10608 -I.pioenvs/uno/FrameworkArduino -I.pioenvs/uno/FrameworkArduinoVariant .pioenvs/uno/FrameworkArduino/HardwareSerial.cpp
/home/glyn/Downloads/dev/platformio_test/src/main.ino: In function 'void setup()':
/home/glyn/Downloads/dev/platformio_test/src/main.ino:186:18: error: 'emonPi_startup' was not declared in this scope
if (RF_STATUS==1) RF_Setup();
^
/home/glyn/Downloads/dev/platformio_test/src/main.ino:188:40: error: 'check_for_DS18B20' was not declared in this scope
emonPi_LCD_Startup();
^
/home/glyn/Downloads/dev/platformio_test/src/main.ino:188:8: warning: unused variable 'numSensors' [-Wunused-variable]
emonPi_LCD_Startup();
^
/home/glyn/Downloads/dev/platformio_test/src/main.ino: In function 'void loop()':
/home/glyn/Downloads/dev/platformio_test/src/main.ino:316:24: error: 'send_emonpi_serial' was not declared in this scope

^
/home/glyn/Downloads/dev/platformio_test/src/rf.ino: In function 'void handleInput(char)':
/home/glyn/Downloads/dev/platformio_test/src/rf.ino:134:60: warning: value computed is not used [-Wunused-value]
-     Serial.print((char) ('@' + (nodeID & RF12_HDR_MASK)));
^
/home/glyn/Downloads/dev/platformio_test/src/rf.ino:135:28: warning: value computed is not used [-Wunused-value]
-     Serial.print(F(" i"));
^
/home/glyn/Downloads/dev/platformio_test/src/rf.ino: In function 'boolean RF_Rx_Handle()':
/home/glyn/Downloads/dev/platformio_test/src/rf.ino:51:1: warning: control reaches end of non-void function [-Wreturn-type]
}
^
/home/glyn/Downloads/dev/platformio_test/src/temperature.ino: In function 'int get_temperature(byte)':
/home/glyn/Downloads/dev/platformio_test/src/temperature.ino:28:1: warning: control reaches end of non-void function [-Wreturn-type]
}
^
avr-g++ -o .pioenvs/uno/FrameworkArduino/HardwareSerial0.o -c -fno-exceptions -fno-threadsafe-statics -std=gnu++11 -g -Os -Wall -ffunction-sections -fdata-sections -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO_ARCH_AVR -DARDUINO_AVR_UNO -DARDUINO=10608 -I.pioenvs/uno/FrameworkArduino -I.pioenvs/uno/FrameworkArduinoVariant .pioenvs/uno/FrameworkArduino/HardwareSerial0.cpp
scons: *** [.pioenvs/uno/src/tmp_ino_to.o] Error 1

[valeros]

Hi @twpayne
The simplest workaround is to add needed function declarations to firmware.ino right before includes, something like that:

extern void emonPi_startup();
extern void send_emonpi_serial();  
extern byte check_for_DS18B20(); 

#include <JeeLib.h>

[glynhudson]

Thanks, that did the trick 👍

[ivankravets]

@glynhudson This is a bug. Please open a separate issue.

[ivankravets]

@glynhudson I've just looked into this issue and found the problem. Please place comments for the prototypes above the declaration. For example, please replace https://github.com/openenergymonitor/emonpi/blob/master/firmware/firmware/startup.ino#L2 to

//Used in emonPi startup to detect presence of AC wavefrom and estimate VRMS voltage
double calc_rms(int pin, int samples) {

PlatformIO ino to cpp coverter doesn't touch comments from the files while Arduino IDE does.

[glynhudson]

Nice, this did the trick 👍

Thanks a lot, I have now migrated my project to platformio, with travisCI build testing :-D

https://github.com/openenergymonitor/emonpi/tree/master/firmware