Improve diagnostic checking for va_start to also warn on other instances of undefined behavior, such as a parameter declared with the register keyword in C, or a parameter of a type that undergoes default argument promotion.
This helps cover some more of the CERT secure coding rule EXP58-CPP. Pass an object of the correct type to va_start (https://www.securecoding.cert.org/confluence/display/cplusplus/EXP58-CPP.+Pass+an+object+of+the+correct+type+to+va_start).
llvm-svn: 267338
diff --git a/clang/test/SemaCXX/varargs.cpp b/clang/test/SemaCXX/varargs.cpp
new file mode 100644
index 0000000..6a18837
--- /dev/null
+++ b/clang/test/SemaCXX/varargs.cpp
@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 -fsyntax-only -std=c++03 -verify %s
+
+class string;
+void f(const string& s, ...) { // expected-note {{parameter of type 'const string &' is declared here}}
+ __builtin_va_list ap;
+ __builtin_va_start(ap, s); // expected-warning {{passing an object of reference type to 'va_start' has undefined behavior}}
+}
+
+void g(register int i, ...) {
+ __builtin_va_list ap;
+ __builtin_va_start(ap, i); // okay
+}