1 files changed, 44 insertions, 0 deletions
diff --git a/test/Sema/implicit-ms-builtin-decl.c b/test/Sema/implicit-ms-builtin-decl.c
new file mode 100644
index 0000000000000..9a3e410c47d80
--- /dev/null
+++ b/test/Sema/implicit-ms-builtin-decl.c
@@ -0,0 +1,44 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -fsyntax-only -verify %s -fms-extensions
+// RUN: %clang_cc1 -triple i386-unknown-unknown -fsyntax-only -verify %s -fms-extensions
+
+void f() {
+  (void)_byteswap_ushort(42); // expected-warning{{implicitly declaring library function '_byteswap_ushort'}} \
+  // expected-note{{include the header <stdlib.h> or explicitly provide a declaration for '_byteswap_ushort'}}
+  (void)_byteswap_uint64(42LL); // expected-warning{{implicitly declaring library function '_byteswap_uint64'}} \
+  // expected-note{{include the header <stdlib.h> or explicitly provide a declaration for '_byteswap_uint64'}}
+}
+
+void _byteswap_ulong(); // expected-warning{{incompatible redeclaration of library function '_byteswap_ulong'}} \
+// expected-note{{'_byteswap_ulong' is a builtin}}
+
+unsigned short _byteswap_ushort(unsigned short);
+unsigned long long _byteswap_uint64(unsigned long long);
+
+void g() {
+  (void)_byteswap_ushort(42);
+  (void)_byteswap_uint64(42LL);
+}
+
+#if defined(__x86_64__)
+void h() {
+  (void)__mulh(21, 2);  // expected-warning{{implicitly declaring library function '__mulh'}} \
+  // expected-note{{include the header <intrin.h> or explicitly provide a declaration for '__mulh'}}
+  (void)__umulh(21, 2); // expected-warning{{implicitly declaring library function '__umulh'}} \
+  // expected-note{{include the header <intrin.h> or explicitly provide a declaration for '__umulh'}}
+}
+
+long long __mulh(long long, long long);
+unsigned long long __umulh(unsigned long long, unsigned long long);
+
+void i() {
+  (void)__mulh(21, 2);
+  (void)__umulh(21, 2);
+}
+#endif
+
+#if defined(i386)
+void h() {
+  (void)__mulh(21LL, 2LL);  // expected-warning{{implicit declaration of function '__mulh' is invalid}}
+  (void)__umulh(21ULL, 2ULL);  // expected-warning{{implicit declaration of function '__umulh' is invalid}}
+}
+#endif