Sketch with math function fails to compile in PlatformIO

[maxgerhardt]

Basic Infos

• This issue complies with the issue POLICY doc.
• I have read the documentation at readthedocs and the issue is not addressed there.
• I have tested that the issue is present in current master branch (aka latest git).
• I have searched the issue tracker for a similar issue.
• If there is a stack dump, I have decoded it.
• I have filled out all fields below.

Platform

• Hardware: ESP-12
• Core Version: 3.0.1
• Development Env: Platformio
• Operating System: Windows

Settings in IDE

• Module: Wemos D1 mini
• Flash Mode: dio
• Flash Size: 4MB
• lwip Variant: v2 Lower Memory
• Reset Method: [ck|nodemcu]
• Flash Frequency: [40Mhz]
• CPU Frequency: 80Mhz
• Upload Using: SERIAL
• Upload Speed: 115200

Problem Description

A sketch making use of certain math functions, like ceill() and some C++ constructs fails to compile in PlatformIO, but compiles fine in the Arduino IDE.

MCVE Sketch

Per https://community.platformio.org/t/multiple-definition-of-ceill/22823.

src\main.cpp:

#include <Arduino.h>
#include <buggy_lib.h>

void setup() {
  long double res = (long double) Serial.parseFloat();
  res = ceill(res);
  Serial.print("Result: ");
  Serial.println((double) res);
  
  //make use of the global variable, otherwise we don't get that error.
  for(auto& x : RANGE_VOLTAGE) {
    Serial.println(x.first);
  }
}

void loop() {
}

with

lib\buggy_lib\buggy_lib.h:

#ifndef _BUGGY_LIB_H
#define _BUGGY_LIB_H

#include <cstdlib> // Needed for uint8_t
#include <string>
#include <unordered_map>
using std::unordered_map;
using std::string;

struct Range_Dict
{
		float value_multiplier;
		int dp_digit_position;
		string display_unit;
};

typedef unordered_map<uint8_t, Range_Dict> range_dict_map_t;

extern range_dict_map_t RANGE_VOLTAGE;

#endif /* _BUGGY_LIB_H */

---

lib\buggy_lib\buggy_lib.cpp:

#include "buggy_lib.h"

range_dict_map_t RANGE_VOLTAGE = {
    {0b0110000, {1e0, 4, "V"}},  //2.2000V
    {0b0110001, {1e0, 3, "V"}},  //22.000V
    {0b0110010, {1e0, 2, "V"}},  //220.00V
    {0b0110011, {1e0, 1, "V"}},  //2200.0V
    {0b0110100, {1e-3, 2,"mV"}}  //220.00mV
};

Result in PlatformIO:

c:/users/max/.platformio/packages/toolchain-xtensa@2.100300.0/bin/../lib/gcc/xtensa-lx106-elf/10.3.0/../../../../xtensa-lx106-elf/bin/ld.exe: C:\Users\Max\.platformio\packages\framework-arduinoespressif8266\tools\sdk\lib\libstdc++.a(math_stubs_long_double.o): in function `ceill':
/workdir/repo/gcc-gnu/libstdc++-v3/src/c++98/math_stubs_long_double.cc:76: multiple definition of `ceill'; c:/users/max/.platformio/packages/toolchain-xtensa@2.100300.0/bin/../lib/gcc/xtensa-lx106-elf/10.3.0/../../../../xtensa-lx106-elf/lib\libm.a(lib_a-ceill.o):/workdir/repo/newlib/newlib/libm/common/ceill.c:38: first defined here
collect2.exe: error: ld returned 1 exit status

Result in the Arduino IDE when the same library is also added in a new library folder:

Linking everything together...
"C:\\Users\\Max\\AppData\\Local\\Arduino15\\packages\\esp8266\\tools\\xtensa-lx106-elf-gcc\\3.0.3-gcc10.3-9bcba0b/bin/xtensa-lx106-elf-gcc" -fno-exceptions -Wl,-Map "-Wl,C:\\Users\\Max\\AppData\\Local\\Temp\\arduino_build_985255/ceill_test.ino.map" -g -w -Werror=return-type -Os -nostdlib -Wl,--no-check-sections -u app_entry -u _printf_float -u _scanf_float -Wl,-static "-LC:\\Users\\Max\\AppData\\Local\\Arduino15\\packages\\esp8266\\hardware\\esp8266\\3.0.1/tools/sdk/lib" "-LC:\\Users\\Max\\AppData\\Local\\Arduino15\\packages\\esp8266\\hardware\\esp8266\\3.0.1/tools/sdk/lib/NONOSDK22x_190703" "-LC:\\Users\\Max\\AppData\\Local\\Temp\\arduino_build_985255" "-LC:\\Users\\Max\\AppData\\Local\\Arduino15\\packages\\esp8266\\hardware\\esp8266\\3.0.1/tools/sdk/libc/xtensa-lx106-elf/lib" -Tlocal.eagle.flash.ld -Wl,--gc-sections -Wl,-wrap,system_restart_local -Wl,-wrap,spi_flash_read -o "C:\\Users\\Max\\AppData\\Local\\Temp\\arduino_build_985255/ceill_test.ino.elf" -Wl,--start-group "C:\\Users\\Max\\AppData\\Local\\Temp\\arduino_build_985255\\sketch\\ceill_test.ino.cpp.o" "C:\\Users\\Max\\AppData\\Local\\Temp\\arduino_build_985255\\libraries\\buggy_lib\\buggy_lib.cpp.o" "C:\\Users\\Max\\AppData\\Local\\Temp\\arduino_cache_987583\\core\\core_826f2e61193dda5f059720593f4d9b02.a" -lhal -lphy -lpp -lnet80211 -llwip2-536-feat -lwpa -lcrypto -lmain -lwps -lbearssl -lespnow -lsmartconfig -lairkiss -lwpa2 -lstdc++ -lm -lc -lgcc -Wl,--end-group "-LC:\\Users\\Max\\AppData\\Local\\Temp\\arduino_build_985255"
..
Der Sketch verwendet 268841 Bytes (25%) des Programmspeicherplatzes. Das Maximum sind 1044464 Bytes.
Globale Variablen verwenden 29144 Bytes (35%) des dynamischen Speichers, 52776 Bytes für lokale Variablen verbleiben. Das Maximum sind 81920 Bytes.

The cause of this lies within the linking order of the libraries libstdc++ and libm (libmath). The Arduino does

-lhal -lphy -lpp -lnet80211 -llwip2-536-feat -lwpa -lcrypto -lmain -lwps -lbearssl -lespnow -lsmartconfig -lairkiss -lwpa2 -lstdc++ -lm -lc -lgcc

While PlatformIO, due to the platformio-build.py doing a simple Append() to the end in regards to the libraries and not respecting the original position dicated by the platform.txt, does

-lhal -lphy -lpp -lnet80211 -lwpa -lcrypto -lmain -lwps -lbearssl -lespnow -lsmartconfig -lairkiss -lwpa2 -lm -lc -lgcc -llwip2-536-feat -lstdc++

A PR with a fix will follow soon.

Debug Messages

None relevant