GNU Arm Embedded Toolchain

scanf fails on "%hhx"

Bug #1598122 reported by john
6
This bug affects 1 person
Affects Status Importance Assigned to Milestone
GNU Arm Embedded Toolchain
Invalid
Undecided
Unassigned

Bug Description

unsigned char i;
sscanf("9f", "%hhx", &i);
This code yields i = 9, which is wrong.

unsigned short i;
sscanf("9f", "%hx", &i);
This code yields i = 0x9f, which is correct.

Revision history for this message
Andre Vieira (andre-simoesdiasvieira) wrote :

Hi John,

I agree with the fact the behavior you are observing is wrong. However, I am not able to reproduce it with the latest release. What version are you using?

Cheers,
Andre

Revision history for this message
john (jkovach) wrote :

Hi Andre,

It's 4.8 2014q3.
LDFLAGS=-Wl,-Map=$(MAP),--gc-sections -fwhole-program -static --specs=nano.specs -lc -lm -lnosys

Revision history for this message
Andre Vieira (andre-simoesdiasvieira) wrote :

Ah that explains it. You are linking it against newlib-nano, which does not support C99 IO formats. I.e. Newlib-nano does not support 8bit types IO formatting.

Changed in gcc-arm-embedded:
status: New → Invalid
Revision history for this message
john (jkovach) wrote :

Thank you for the explanation, Andre.

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