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Date of registration: Nov 11th 2015

Posts: 10


Friday, February 10th 2017, 10:21am

Addional compiler options for Clang


i switched compiler from gcc to clang. Now we are getting a lot of warnings like :

"passing 'uint8_t *' (aka 'unsigned char *') to parameter of type 'char *' converts between pointers to integer types with different sign"

So i was trying to use "/J " compiler switch to handle chars as unsigned. But if i Add "/J" to addional compiler arguments, i always get a Error like:

"error reading '/J'" :-(
What can i do?

SEGGER - Johannes

Super Moderator

Date of registration: Aug 31st 2012

Posts: 377


Friday, February 10th 2017, 11:22am


Use -fno-signed-char instead of /J




Date of registration: Nov 11th 2015

Posts: 10


Friday, February 10th 2017, 5:33pm

Hi Johannes,

I tried your solution. The compiler was not complaining about the option anymore. But we still get the warning.
It seem's the compiler is ignoring the option... or i understand something wrong.

Please see attached pictures
jenlan has attached the following images:
  • SEGGER Embedded Studio_compileroption1.png
  • SEGGER Embedded Studio_compileroption2.png
  • SEGGER Embedded Studio_compileroption3.png