analyzer: fix -Wanalyzer-va-arg-type-mismatch false +ve on int types [PR111289]

gcc/analyzer/ChangeLog:
	PR analyzer/111289
	* varargs.cc (representable_in_integral_type_p): New.
	(va_arg_compatible_types_p): Add "arg_sval" param.  Handle integer
	types.
	(kf_va_arg::impl_call_pre): Pass arg_sval to
	va_arg_compatible_types_p.

gcc/testsuite/ChangeLog:
	PR analyzer/111289
	* c-c++-common/analyzer/stdarg-pr111289-int.c: New test.
	* c-c++-common/analyzer/stdarg-pr111289-ptr.c: New test.

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

2 files changed, 108 insertions, 0 deletions

diff --git a/gcc/testsuite/c-c++-common/analyzer/stdarg-pr111289-int.c b/gcc/testsuite/c-c++-common/analyzer/stdarg-pr111289-int.c
new file mode 100644
index 0000000..33d8316
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/analyzer/stdarg-pr111289-int.c
@@ -0,0 +1,69 @@
+#include <stdarg.h>
+#include <stdint.h>
+#include <limits.h>
+
+typedef unsigned int mode_t;
+
+extern void openat (int, const char *, int, mode_t);
+
+/* Signed vs unsigned of same integral type.  */
+
+static void
+test_1 (char const *name, ...)
+{
+  va_list arg;
+  va_start (arg, name);
+
+  mode_t mode = va_arg (arg, mode_t); /* { dg-bogus "-Wanalyzer-va-arg-type-mismatch" } */
+
+  va_end (arg);
+  openat (-42, name, 0, mode);
+}
+
+void
+call_test_1 ()
+{
+  test_1 ("nonexist.ent/", 0600);
+}
+
+/* Not the same size: small enough for int promotion.  */
+
+int16_t global_2;
+
+static void
+test_2 (char const *name, ...)
+{
+  va_list arg;
+  va_start (arg, name);
+
+  global_2 = va_arg (arg, int16_t); /* { dg-warning "promoted to 'int'" } */
+
+  va_end (arg);
+}
+
+void
+call_test_2 ()
+{
+  test_2 ("nonexist.ent/", 42);
+}
+
+/* Not the same size: too big for int promotion.  */
+
+long long global_3;
+
+static void
+test_3 (char const *name, ...)
+{
+  va_list arg;
+  va_start (arg, name);
+
+  global_3 = va_arg (arg, long long); /* { dg-warning "'va_arg' expected 'long long int' but received 'int' for variadic argument 1 of 'arg'" } */
+
+  va_end (arg);
+}
+
+void
+call_test_3 ()
+{
+  test_3 ("nonexist.ent/", 42);
+}
diff --git a/gcc/testsuite/c-c++-common/analyzer/stdarg-pr111289-ptr.c b/gcc/testsuite/c-c++-common/analyzer/stdarg-pr111289-ptr.c
new file mode 100644
index 0000000..7bdbf25
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/analyzer/stdarg-pr111289-ptr.c
@@ -0,0 +1,39 @@
+#include <stdarg.h>
+
+static void *
+test_1 (const char *fmt, ...)
+{
+  va_list arg;
+  va_start (arg, fmt);
+
+  void *p = va_arg (arg, void *); /* { dg-bogus "-Wanalyzer-va-arg-type-mismatch" } */
+
+  va_end (arg);
+
+  return p;
+}
+
+void *
+call_test_1 ()
+{
+  return test_1 ("fmt", "foo");
+}
+
+static char *
+test_2 (const char *fmt, ...)
+{
+  va_list arg;
+  va_start (arg, fmt);
+
+  char *p = va_arg (arg, char *); /* { dg-bogus "-Wanalyzer-va-arg-type-mismatch" } */
+
+  va_end (arg);
+
+  return p;
+}
+
+char *
+call_test_2 (void *q)
+{
+  return test_2 ("fmt", q);
+}