Compiler/CC1350: vsnprintf extra format character not working

spanky

Part Number: CC1350

Tool/software: TI C/C++ Compiler

This is a total mystery to me. My code was working previously. I made some minor unrelated changes then put it on the shelf for a while. Now the vsnprintf doesn't handle extra formatting. I cant figure out what I would have done.

vsnprintf doesn't respect "%08x" (for leading zeros), but it does "%x". It just outputs "8x" instead of replacing the format specifier with the argument.

vsnprintf also doesn't handle "%u"

Any idea what could be causing that? This code was previously working, so its not a problem with my immediate code. Maybe some configuration or system code?

Also, the same format specifiers work fine when using System_printf.

over 7 years ago

0 Keith Barkley over 7 years ago

Guru 41995 points

The usual suspect for problems like this is to increase the amount of stack. The other thing to look at is if the extra code you added is clobbering the stack somehow.

0 Archaeologist over 7 years ago

TI__Guru* 84225 points

Make sure you are using the compiler option --printf_support=full
Some targets default --printf_support=minimal to save code size; this disables things like format width specifiers.

0 spanky over 7 years ago in reply to Archaeologist

Expert 2710 points

Ahhh, looks like I had set --printf_support=minimal to try and get more stack space, but forgot to set it back before I shelved the project.

That brings up a bigger question:
If printf_support was set to minimal, why did System_printf() handle the extra specifiers? Does vsnprintf (and its siblings) use a different codebase from System_printf?

0 Keith Barkley over 7 years ago in reply to spanky

Guru 41995 points

I can't find the thread now, but the System_printf() comes from xdc.

0 George Mock over 7 years ago in reply to spanky

TI__Guru**** 244790 points

spanky said:
Does vsnprintf (and its siblings) use a different codebase from System_printf?

Yes. -George

0 Keith Barkley over 7 years ago in reply to spanky

Guru 41995 points

Here is the thread I was referring to:
e2e.ti.com/.../697865

0 spanky over 7 years ago in reply to Keith Barkley

Expert 2710 points

So if there are System_xxprintf functions in the XDC tools, and another completely independent xxprintf implementation in the standard libraries, which one should I use?

I guess I'm only using System_printf for printing out debugging messages, so i could probably cut that.

0 Chester Gillon over 7 years ago in reply to spanky

Guru 92251 points

spanky said:
So if there are System_xxprintf functions in the XDC tools, and another completely independent xxprintf implementation in the standard libraries, which one should I use?

The System_xxprintf functions don't support the full range of format strings. E.g. see CCS: How to print unsigned long long (uint64_t ) using System_printf() and System_flush()

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Compiler/CC1350: vsnprintf extra format character not working