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Set -funsigned-char flag when exporting to GCC

Topic last updated 01 Mar 2016, by Austin Blackstone. 1 reply
Aaron Campbell
01 Feb 2016

Here's a minor feature request for exporting to GCC and GCC-based environments (such as KDS and Atmel Studio): add the compiler flag -funsigned-char in exported projects by default.

The mbed handbook lists the char type as being unsigned (here), but the C standard does not specify, and in GCC chars are signed by default (see http://stackoverflow.com/a/2054959/1858923). This leads to errors when exporting projects that assume that chars are unsigned, such as Neil Thiessen's SDFileSystem. If we automatically set -funsigned-char in exported projects, we reduce the inconsistencies between the mbed online compiler and other target compilers for exported projects.

Austin Blackstone
01 Mar 2016

Aaron,

I've logged the issue internally and we will look into implimenting this change. Thank you for pointing this out!

Keep up the awesome work!

-Austin