Not possible to remove -fno-rtti from build flags

#1

Operating system:
Windows 10, using Atom with PlatformIO Package.

PlatformIO Version (platformio --version):
3.5.3

Description of problem
I tried every information found in the platformio docs to remove the build flag ‘-fno-rtti’ from the build process, because I want to use the typeid() operator of C++.
However, it seems to compile with the flag every time, regardless of what I do.

Compiler output:

error: cannot use typeid with -fno-rtti
Serial.printf(typeid(test).name());

The content of platformio.ini:

[env:nodemcuv2]
platform = espressif8266
board = nodemcuv2
framework = arduino
upload_port = COM11
upload_speed = 921600
build_unflags = -fno-rtti
1 Like
#2

The -fno-rtti is added as CXX Flag in platform-espressif8266/main.py at develop · platformio/platform-espressif8266 · GitHub

This file is in your .platformio folder in your Home directory (C:\Users\<Username>\.platformio). Uncommenting this line with # makes your code compile (while additionally defining test as something like struct test { int t; };)

1 Like
#3

Hm I’ve tried a few ways to remove the -fno-rtti flag at runtime and all have failed.

platformio.ini

[env:nodemcuv2]
platform = espressif8266
board = nodemcuv2
framework = arduino
extra_scripts = add_rtti.py

main.cpp

#include <Arduino.h>

struct test { int someThing; };

void setup() {
	Serial.begin(115200);
	Serial.printf("%s", typeid(test).name());
}

void loop() { }

add_rtti.py

Import("env")

print(env)
print(type(env))
print(type(env['CXXFLAGS']))
print("Before")
print(str(env['CXXFLAGS']))
env['CXXFLAGS'].remove("-fno-rtti")
print("After")
print(str(env['CXXFLAGS']))

env.ProcessUnFlags("-fno-rtti")

The script appears to be removing the flag but it’s in the final build command anyways.

No dependencies
<SCons.Script.SConscript.SConsEnvironment object at 0x042F0AD0>
<class 'SCons.Script.SConscript.SConsEnvironment'>
<class 'SCons.Util.CLVar'>
Before
-fno-rtti -fno-exceptions -std=c++11
After
-fno-exceptions -std=c++11

@ivankravets, wasn’t there a case before with -DVECT_TAB_ADDR where this worked but there were regressions later? Is my script wrong or is something broken? Adding build_unflags = -fno-rtti has no effect either.

1 Like
#4

Fixed in