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

[Luis Machado <lgustavo at codesourcery dot com>]

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?

2013-11-26  Luis Machado  <lgustavo@codesourcery.com>

	gdb/testsuite/
	* gdb.base/callfuncs.c (main): Assign malloc's return value
	and free it afterwards.
	* gdb.base/charset-malloc.c (malloc_stub): Likewise.
	* gdb.base/printcmds.c (main): Likewise.
	* gdb.base/randomize.c (main): Free "p".
	* gdb.base/setvar.c (dummy): Assign malloc's return value
	and free it afterwards.

diff --git a/gdb/testsuite/gdb.base/callfuncs.c b/gdb/testsuite/gdb.base/callfuncs.c
index 0d76ee9..3872f5c 100644
--- a/gdb/testsuite/gdb.base/callfuncs.c
+++ b/gdb/testsuite/gdb.base/callfuncs.c
@@ -652,9 +652,13 @@ voidfunc (void)
 
 int main ()
 {
-  malloc(1);
+  void *p = malloc (1);
   t_double_values(double_val1, double_val2);
   t_structs_c(struct_val1);
+
+  if (p != NULL)
+    free (p);
+
   return 0 ;
 }
 
diff --git a/gdb/testsuite/gdb.base/charset-malloc.c b/gdb/testsuite/gdb.base/charset-malloc.c
index 58242a2..54a9bd6 100644
--- a/gdb/testsuite/gdb.base/charset-malloc.c
+++ b/gdb/testsuite/gdb.base/charset-malloc.c
@@ -31,5 +31,8 @@ malloc_stub (void)
 {
   /* charset.exp wants to allocate memory for constants.  So make sure malloc
      gets linked into the program.  */
-  malloc (1);
+  void *p = malloc (1);
+
+  if (p != NULL)
+    free (p);
 }
diff --git a/gdb/testsuite/gdb.base/printcmds.c b/gdb/testsuite/gdb.base/printcmds.c
index d80c13d..806f421 100644
--- a/gdb/testsuite/gdb.base/printcmds.c
+++ b/gdb/testsuite/gdb.base/printcmds.c
@@ -218,10 +218,13 @@ char invalid_RRR[] = "aaaaaaaaaaaaaaaaaaaa"
 
 int main ()
 {
-  malloc(1);
+  void *p = malloc (1);
 
   /* Prevent AIX linker from removing variables.  */
   return ctable1[0] + ctable2[0] + int1dim[0] + int2dim[0][0]
     + int3dim[0][0][0] + int4dim[0][0][0][0] + teststring[0] +
       *parrays -> array1 + a1[0] + a2[0];
+
+  if (p != NULL)
+    free (p);
 }
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 */
 }
diff --git a/gdb/testsuite/gdb.base/setvar.c b/gdb/testsuite/gdb.base/setvar.c
index 3a80b22..0022dc0 100644
--- a/gdb/testsuite/gdb.base/setvar.c
+++ b/gdb/testsuite/gdb.base/setvar.c
@@ -204,7 +204,7 @@ dummy ()
 {
   /* setvar.exp wants to allocate memory for constants.  So make sure malloc
      gets linked into the program.  */
-  malloc (1);
+  void *p = malloc (1);
 
   /* Some linkers (e.g. on AIX) remove unreferenced variables,
      so make sure to reference them. */
@@ -278,4 +278,7 @@ dummy ()
   sef.field = s1;
   uef.field = u1;
 #endif
+
+  if (p != NULL)
+    free (p);
 }