sparse: add __builtin_va_arg_pack() and __builtin_va_arg_pack_len()

this patch stops sparse from complaining about them not being defined:

    /usr/include/bits/stdio2.h:98:25: error: undefined identifier '__builtin_va_arg_pack'
    /usr/include/bits/stdio2.h:98:25: error: not a function <noident>

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Christopher Li <sparse@chrisli.org>

2 files changed, 22 insertions, 0 deletions

diff --git a/lib.c b/lib.c
index 7e822eb7..3f687ae9 100644
--- a/lib.c
+++ b/lib.c
@@ -777,6 +777,7 @@ void declare_builtin_functions(void)
 	add_pre_buffer("extern long __builtin_alpha_cmpbge(long, long);\n");
 	add_pre_buffer("extern long __builtin_labs(long);\n");
 	add_pre_buffer("extern double __builtin_fabs(double);\n");
+	add_pre_buffer("extern __SIZE_TYPE__ __builtin_va_arg_pack_len(void);\n");
 	add_pre_buffer("extern void __sync_synchronize();\n");
 	add_pre_buffer("extern int __sync_bool_compare_and_swap(void *, ...);\n");
 
@@ -876,6 +877,7 @@ void create_builtin_stream(void)
 	add_pre_buffer("#define __builtin_va_copy(dest, src) ({ dest = src; (void)0; })\n");
 	add_pre_buffer("#define __builtin_va_end(arg)\n");
 	add_pre_buffer("#define __builtin_ms_va_end(arg)\n");
+	add_pre_buffer("#define __builtin_va_arg_pack()\n");
 
 	/* FIXME! We need to do these as special magic macros at expansion time! */
 	add_pre_buffer("#define __BASE_FILE__ \"base_file.c\"\n");
diff --git a/validation/builtin_va_arg_pack.c b/validation/builtin_va_arg_pack.c
new file mode 100644
index 00000000..3426b86b
--- /dev/null
+++ b/validation/builtin_va_arg_pack.c
@@ -0,0 +1,20 @@
+extern void v(int a, ...);
+
+extern inline __attribute__((__always_inline__)) void f(int a, ...)
+{
+	__SIZE_TYPE__ b = __builtin_va_arg_pack_len();
+}
+
+extern inline __attribute__((__always_inline__)) void g(int a, ...)
+{
+	v(a, __builtin_va_arg_pack());
+}
+
+static void h(void)
+{
+	f(0, 0);
+	g(0, 0);
+}
+/*
+ * check-name: __builtin_va_arg_pack()
+ */