diff options
| -rw-r--r-- | clang/lib/Sema/SemaChecking.cpp | 13 | ||||
| -rw-r--r-- | clang/test/Sema/varargs.c | 20 |
2 files changed, 30 insertions, 3 deletions
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp index 81dc23724e9..f3f204ffa04 100644 --- a/clang/lib/Sema/SemaChecking.cpp +++ b/clang/lib/Sema/SemaChecking.cpp @@ -3240,8 +3240,17 @@ bool Sema::SemaBuiltinVAStartImpl(CallExpr *TheCall) { Diag(TheCall->getArg(1)->getLocStart(), diag::warn_second_arg_of_va_start_not_last_named_param); else if (IsCRegister || Type->isReferenceType() || - Type->isPromotableIntegerType() || - Type->isSpecificBuiltinType(BuiltinType::Float)) { + Type->isSpecificBuiltinType(BuiltinType::Float) || [=] { + // Promotable integers are UB, but enumerations need a bit of + // extra checking to see what their promotable type actually is. + if (!Type->isPromotableIntegerType()) + return false; + if (!Type->isEnumeralType()) + return true; + const EnumDecl *ED = Type->getAs<EnumType>()->getDecl(); + return !(ED && + Context.typesAreCompatible(ED->getPromotionType(), Type)); + }()) { unsigned Reason = 0; if (Type->isReferenceType()) Reason = 1; else if (IsCRegister) Reason = 2; diff --git a/clang/test/Sema/varargs.c b/clang/test/Sema/varargs.c index 457d84c212f..27d49ea1f2e 100644 --- a/clang/test/Sema/varargs.c +++ b/clang/test/Sema/varargs.c @@ -1,5 +1,6 @@ -// RUN: %clang_cc1 -fsyntax-only -verify %s +// RUN: %clang_cc1 -fsyntax-only -verify %s -triple i386-pc-unknown // RUN: %clang_cc1 -fsyntax-only -verify %s -triple x86_64-apple-darwin9 +// RUN: %clang_cc1 -fsyntax-only -fms-compatibility -DMS -verify %s void f1(int a) { @@ -94,3 +95,20 @@ void f12(register int i, ...) { // expected-note {{parameter of type 'int' is d __builtin_va_start(ap, i); // expected-warning {{passing a parameter declared with the 'register' keyword to 'va_start' has undefined behavior}} __builtin_va_end(ap); } + +enum __attribute__((packed)) E1 { + one1 +}; + +void f13(enum E1 e, ...) { + __builtin_va_list va; + __builtin_va_start(va, e); +#ifndef MS + // In Microsoft compatibility mode, all enum types are int, but in + // non-ms-compatibility mode, this enumeration type will undergo default + // argument promotions. + // expected-note@-7 {{parameter of type 'enum E1' is declared here}} + // expected-warning@-6 {{passing an object that undergoes default argument promotion to 'va_start' has undefined behavior}} +#endif + __builtin_va_end(va); +} |
