[PATCH] Fix gimple-ssa-sprintf.c ICE (PR tree-optimization/83198)

[Richard Biener]

On Wed, 13 Dec 2017, Jakub Jelinek wrote:

> Hi!
> 
> This patch fixes 2 issues in format_floating.  One is that when determining
> precision, we should consider solely the type *printf* will read the
> argument as (i.e. double unless L or ll modifier is used, in which case
> long double), not the type of the argument, because the corresponding
> argument could have any type, even not floating, or say __float128 etc.
> 
> This is fixed in the first 2 hunks.
> 
> The last hunk is to treat REAL_CSTs arguments of incompatible types
> as unknown argument, we really don't know what say __float128 passed to
> %f or double passed to %La will do; that is something diagnosed by -Wformat,
> so the patch just treats it as arbitrary value of the type.
> 
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

Ok.

Richard.

> 2017-12-13  Jakub Jelinek  <jakub@redhat.com>
> 
> 	PR tree-optimization/83198
> 	* gimple-ssa-sprintf.c (format_floating): Set type solely based on
> 	dir.modifier, regardless of TREE_TYPE (arg).  Assume non-REAL_CST
> 	value if arg is a REAL_CST with incompatible type.
> 
> 	* gcc.dg/pr83198.c: New test.
> 
> --- gcc/gimple-ssa-sprintf.c.jj	2017-11-03 15:37:04.000000000 +0100
> +++ gcc/gimple-ssa-sprintf.c	2017-12-13 13:37:59.289435623 +0100
> @@ -1885,6 +1885,8 @@ static fmtresult
>  format_floating (const directive &dir, tree arg)
>  {
>    HOST_WIDE_INT prec[] = { dir.prec[0], dir.prec[1] };
> +  tree type = (dir.modifier == FMT_LEN_L || dir.modifier == FMT_LEN_ll
> +	       ? long_double_type_node : double_type_node);
>  
>    /* For an indeterminate precision the lower bound must be assumed
>       to be zero.  */
> @@ -1892,10 +1894,6 @@ format_floating (const directive &dir, t
>      {
>        /* Get the number of fractional decimal digits needed to represent
>  	 the argument without a loss of accuracy.  */
> -      tree type = arg ? TREE_TYPE (arg) :
> -	(dir.modifier == FMT_LEN_L || dir.modifier == FMT_LEN_ll
> -	 ? long_double_type_node : double_type_node);
> -
>        unsigned fmtprec
>  	= REAL_MODE_FORMAT (TYPE_MODE (type))->p;
>  
> @@ -1946,7 +1944,9 @@ format_floating (const directive &dir, t
>  	}
>      }
>  
> -  if (!arg || TREE_CODE (arg) != REAL_CST)
> +  if (!arg
> +      || TREE_CODE (arg) != REAL_CST
> +      || !useless_type_conversion_p (type, TREE_TYPE (arg)))
>      return format_floating (dir, prec);
>  
>    /* The minimum and maximum number of bytes produced by the directive.  */
> --- gcc/testsuite/gcc.dg/pr83198.c.jj	2017-12-13 13:43:36.056192309 +0100
> +++ gcc/testsuite/gcc.dg/pr83198.c	2017-12-13 13:47:11.716474956 +0100
> @@ -0,0 +1,18 @@
> +/* PR tree-optimization/83198 */
> +/* { dg-do compile } */
> +/* { dg-options "-Wall -Wno-format" } */
> +
> +int
> +foo (char *d[6], int x)
> +{
> +  int r = 0;
> +  r += __builtin_sprintf (d[0], "%f", x);
> +  r += __builtin_sprintf (d[1], "%a", x);
> +  r += __builtin_sprintf (d[2], "%f", "foo");
> +  r += __builtin_sprintf (d[3], "%a", "bar");
> +#ifdef __SIZEOF_FLOAT128__
> +  r += __builtin_sprintf (d[4], "%a", 1.0Q);
> +  r += __builtin_sprintf (d[5], "%Lf", 1.0Q);
> +#endif
> +  return r;
> +}
> 
> 	Jakub
> 
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nuernberg)