Re: [PATCH, testsuite] Prevent warnings due to dummy malloc calls.

[Doug Evans <dje@google.com>]

On Tue, Nov 26, 2013 at 11:19 AM, Luis Machado
<lgustavo@codesourcery.com> wrote:
> Hi,
>
> When running GDB's testsuite with libraries/compilers that are more
> restrictive in terms of warnings, i've found that some tests were failing
> due to malloc being called but not having its return value assigned to any
> variables, leading to this warning:
>
> warning: ignoring return value of 'malloc', declared with attribute
> warn_unused_result [-Wunused-result]
>
> The following patch adjusts those testcases to silence the warnings by (1)
> assigning malloc's return value and (2) freeing that pointer later on.
>
> In the case of gdb.base/randomize.c, we're missing a free call, which leads
> to an unused variable warning.
>
> Ok?

Coping with these kinds of warnings is a really slippery slope, the
testsuite is just not ready IMO.
OTOH, I don't mind changes like this particular one.

One nit:  Please change all occurrences of this:

+  if (p != NULL)
+    free (p);

to this

+  free (p);

It's simpler and equally correct.

The randomize.c case is a bit odd, printing p after it's freed.
Maybe just add a comment explaining why things are the way they are?

diff --git a/gdb/testsuite/gdb.base/randomize.c
b/gdb/testsuite/gdb.base/randomize.c
index 6a65663..127a4c7 100644
--- a/gdb/testsuite/gdb.base/randomize.c
+++ b/gdb/testsuite/gdb.base/randomize.c
@@ -24,5 +24,8 @@ int main()
   p = malloc (1);

+  if (p != NULL)
+    free (p);
+
   return 0; /* print p */
 }