[Rd] use of buffers in sprintf and snprintf

[jing hua zhao]

Hi again,

I realised it is useful to replicate the warnings locally without relying on CRAN automatic check; instead of R(-devel)  CMD check --as-cran package_version.tar.gz one can use

R CMD check --configure-args=""

and in my case the WARNINGS were initially given with https://www.stats.ox.ac.uk/pub/bdr/gcc9/README.txt and those specification might as well used in --configure-args above.

Besst regards,


Jing Hua

________________________________
From: R-devel <r-devel-bounces using r-project.org> on behalf of jing hua zhao <jinghuazhao using hotmail.com>
Sent: 29 May 2019 15:49
To: r-devel using r-project.org
Subject: [Rd] use of buffers in sprintf and snprintf

Dear R-developers,

I am struggling with packaging with sprintf and snprintf() as the following WARNINGS from gcc 9.x,

  hap_c.c:380:46: warning: �%d� directive output may be truncated writing between 1 and 10 bytes into a region of size between 0 and 127 [-Wformat-truncation=]
  hap_c.c:392:46: warning: �%d� directive output may be truncated writing between 1 and 10 bytes into a region of size between 0 and 127 [-Wformat-truncation=]

Essentially, I have

#define MAX_FILENAME_LEN 128
char of1name[MAX_FILENAME_LEN],of2name[MAX_FILENAME_LEN], tempname[MAX_FILENAME_LEN];

...

 snprintf(tempname,sizeof(tempname),"%s.%d", of1name, j);

It looks I could get around with


#define MAX_FILENAME_LEN 128

#define MAX_FILENAME_LEN2 256

char of1name[MAX_FILENAME_LEN],of2name[MAX_FILENAME_LEN], tempname[MAX_FILENAME_LEN2];

...
snprintf(tempname,2*sizeof(tempname)+1,"%s.%d", of1name, j)

It looks a bit waste of resources to me.


Any idea will be greatly appreciated,



Jing Hua

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