analyzer: avoid saying "'0' is NULL"

gcc/analyzer/ChangeLog:
	* sm-malloc.cc (malloc_diagnostic::describe_state_change): Tweak
	the "EXPR is NULL" message for the case where EXPR is a null
	pointer.

gcc/testsuite/ChangeLog:
	* c-c++-common/analyzer/data-model-path-1.c: Check for
	"using NULL here" message.
	* c-c++-common/analyzer/null-deref-pr108251-smp_fetch_ssl_fc_has_early.c:
	Likewise.  Check for "return of NULL" message.
	* c-c++-common/analyzer/null-deref-pr108400-SoftEtherVPN-WebUi.c:
	Likewise.
	* gcc.dg/analyzer/data-model-5.c: Likewise.
	* gcc.dg/analyzer/data-model-5b.c: Likewise.
	* gcc.dg/analyzer/data-model-5c.c: Likewise.
	* gcc.dg/analyzer/torture/pr93647.c: Likewise.

Signed-off-by: David Malcolm <dmalcolm@redhat.com>

8 files changed, 15 insertions, 10 deletions

diff --git a/gcc/analyzer/sm-malloc.cc b/gcc/analyzer/sm-malloc.cc
index 0186268..333dfea 100644
--- a/gcc/analyzer/sm-malloc.cc
+++ b/gcc/analyzer/sm-malloc.cc
@@ -785,8 +785,13 @@ public:
 	else
 	  {
 	    if (change.m_expr)
-	      pp_printf (&pp, "%qE is NULL",
-			 change.m_expr);
+	      {
+		if (zerop (change.m_expr))
+		  pp_printf (&pp, "using NULL here");
+		else
+		  pp_printf (&pp, "%qE is NULL",
+			     change.m_expr);
+	      }
 	    else
 	      pp_printf (&pp, "%qs is NULL",
 			 "<unknown>");
diff --git a/gcc/testsuite/c-c++-common/analyzer/data-model-path-1.c b/gcc/testsuite/c-c++-common/analyzer/data-model-path-1.c
index d7058ea..0609dc8 100644
--- a/gcc/testsuite/c-c++-common/analyzer/data-model-path-1.c
+++ b/gcc/testsuite/c-c++-common/analyzer/data-model-path-1.c
@@ -3,7 +3,7 @@
 static int *__attribute__((noinline))
 callee (void)
 {
-  return NULL;
+  return NULL; /* { dg-message "using NULL here" } */
 }
 
 void test_1 (void)
diff --git a/gcc/testsuite/c-c++-common/analyzer/null-deref-pr108251-smp_fetch_ssl_fc_has_early.c b/gcc/testsuite/c-c++-common/analyzer/null-deref-pr108251-smp_fetch_ssl_fc_has_early.c
index c5f1fa4..4f04e46 100644
--- a/gcc/testsuite/c-c++-common/analyzer/null-deref-pr108251-smp_fetch_ssl_fc_has_early.c
+++ b/gcc/testsuite/c-c++-common/analyzer/null-deref-pr108251-smp_fetch_ssl_fc_has_early.c
@@ -66,7 +66,7 @@ static inline struct connection *__objt_conn(enum obj_type *t)
 static inline struct connection *objt_conn(enum obj_type *t)
 {
  if (!t || *t != OBJ_TYPE_CONN)
-   return (struct connection *) ((void *)0);
+   return (struct connection *) ((void *)0); /* { dg-message "using NULL here" } */
  return __objt_conn(t);
 }
 struct session {
@@ -85,7 +85,7 @@ smp_fetch_ssl_fc_has_early(const struct arg *args, struct sample *smp, const cha
  SSL *ssl;
  struct connection *conn;
 
- conn = objt_conn(smp->sess->origin);
+ conn = objt_conn(smp->sess->origin); /* { dg-message "return of NULL" } */
  ssl = ssl_sock_get_ssl_object(conn);
  if (!ssl)
   return 0;
diff --git a/gcc/testsuite/c-c++-common/analyzer/null-deref-pr108400-SoftEtherVPN-WebUi.c b/gcc/testsuite/c-c++-common/analyzer/null-deref-pr108400-SoftEtherVPN-WebUi.c
index 9dcf7aa..0ebeeff 100644
--- a/gcc/testsuite/c-c++-common/analyzer/null-deref-pr108400-SoftEtherVPN-WebUi.c
+++ b/gcc/testsuite/c-c++-common/analyzer/null-deref-pr108400-SoftEtherVPN-WebUi.c
@@ -60,7 +60,7 @@ void WuExpireSessionKey(WEBUI *wu)
 
 	for(i=0; i<LIST_NUM(wu->Contexts); i++)
 	{
-		STRMAP_ENTRY *entry = (STRMAP_ENTRY*)LIST_DATA(wu->Contexts, i);
+		STRMAP_ENTRY *entry = (STRMAP_ENTRY*)LIST_DATA(wu->Contexts, i); /* { dg-message "'entry' is NULL" } */
 		WU_CONTEXT *context = (WU_CONTEXT*)entry->Value; /* { dg-bogus "dereference of NULL 'entry'" "PR analyzer/108400" { xfail *-*-* } } */
 		if(context->ExpireDate < Tick64())
 		{
diff --git a/gcc/testsuite/gcc.dg/analyzer/data-model-5.c b/gcc/testsuite/gcc.dg/analyzer/data-model-5.c
index b71bad7..78e2752 100644
--- a/gcc/testsuite/gcc.dg/analyzer/data-model-5.c
+++ b/gcc/testsuite/gcc.dg/analyzer/data-model-5.c
@@ -60,7 +60,7 @@ base_obj *alloc_obj (type_obj *ob_type, size_t sz)
 {
   base_obj *obj = (base_obj *)malloc (sz);
   if (!obj)
-    return NULL;
+    return NULL; /* { dg-message "using NULL here" } */
   obj->ob_type = ob_type;
   obj->ob_refcnt = 1;
   return obj;
diff --git a/gcc/testsuite/gcc.dg/analyzer/data-model-5b.c b/gcc/testsuite/gcc.dg/analyzer/data-model-5b.c
index cd6a4df..f66c8c4 100644
--- a/gcc/testsuite/gcc.dg/analyzer/data-model-5b.c
+++ b/gcc/testsuite/gcc.dg/analyzer/data-model-5b.c
@@ -44,7 +44,7 @@ base_obj *alloc_obj (type_obj *ob_type, size_t sz)
 {
   base_obj *obj = (base_obj *)malloc (sz);
   if (!obj)
-    return NULL;
+    return NULL; /* { dg-message "using NULL here" } */
   obj->ob_type = ob_type;
   obj->ob_refcnt = 1;
   return obj;
diff --git a/gcc/testsuite/gcc.dg/analyzer/data-model-5c.c b/gcc/testsuite/gcc.dg/analyzer/data-model-5c.c
index ad4e1d2..1ce355f 100644
--- a/gcc/testsuite/gcc.dg/analyzer/data-model-5c.c
+++ b/gcc/testsuite/gcc.dg/analyzer/data-model-5c.c
@@ -38,7 +38,7 @@ base_obj *alloc_obj (type_obj *ob_type, size_t sz)
 {
   base_obj *obj = (base_obj *)malloc (sz);
   if (!obj)
-    return NULL;
+    return NULL; /* { dg-message "using NULL here" } */
   obj->ob_type = ob_type;
   obj->ob_refcnt = 1;
   return obj;
diff --git a/gcc/testsuite/gcc.dg/analyzer/torture/pr93647.c b/gcc/testsuite/gcc.dg/analyzer/torture/pr93647.c
index fbfe570..194c99a 100644
--- a/gcc/testsuite/gcc.dg/analyzer/torture/pr93647.c
+++ b/gcc/testsuite/gcc.dg/analyzer/torture/pr93647.c
@@ -8,7 +8,7 @@ ky (int);
 void
 wd (void)
 {
-  tz = 0;
+  tz = 0; /* { dg-message "using NULL here" } */
   ky (*tz); /* { dg-warning "dereference of NULL" } */
 }