Merge from 'main' to 'sycl-web' (#16)

  CONFLICT (content): Merge conflict in clang/utils/TableGen/TableGenBackends.h
  CONFLICT (content): Merge conflict in clang/utils/TableGen/TableGen.cpp

Author: abhinavgaba

clang/include/clang/Driver/Options.td

@@ -6358,6 +6358,7 @@ def _SLASH_Zo_ : CLIgnoredFlag<"Zo-">;
 // Unsupported:
 
 def _SLASH_await : CLFlag<"await">;
+def _SLASH_await_COLON : CLJoined<"await:">;
 def _SLASH_constexpr : CLJoined<"constexpr:">;
 def _SLASH_AI : CLJoinedOrSeparate<"AI">;
 def _SLASH_Bt : CLFlag<"Bt">;

clang/include/clang/Sema/Initialization.h

@@ -804,7 +804,7 @@ class InitializationSequence {
     SK_ResolveAddressOfOverloadedFunction,
 
     /// Perform a derived-to-base cast, producing an rvalue.
-    SK_CastDerivedToBaseRValue,
+    SK_CastDerivedToBasePRValue,
 
     /// Perform a derived-to-base cast, producing an xvalue.
     SK_CastDerivedToBaseXValue,

clang/lib/Frontend/InitPreprocessor.cpp

@@ -608,7 +608,7 @@ static void InitializeCPlusPlusFeatureTestMacros(const LangOptions &LangOpts,
     Builder.defineMacro("__cpp_designated_initializers", "201707L");
     Builder.defineMacro("__cpp_impl_three_way_comparison", "201907L");
     //Builder.defineMacro("__cpp_modules", "201907L");
-    //Builder.defineMacro("__cpp_using_enum", "201907L");
+    Builder.defineMacro("__cpp_using_enum", "201907L");
   }
   // C++2b features.
   if (LangOpts.CPlusPlus2b)

clang/lib/Sema/SemaExpr.cpp

@@ -15800,8 +15800,46 @@ ExprResult Sema::BuildVAArgExpr(SourceLocation BuiltinLoc,
     QualType PromoteType;
     if (TInfo->getType()->isPromotableIntegerType()) {
       PromoteType = Context.getPromotedIntegerType(TInfo->getType());
-      if (Context.typesAreCompatible(PromoteType, TInfo->getType()))
+      // [cstdarg.syn]p1 defers the C++ behavior to what the C standard says,
+      // and C2x 7.16.1.1p2 says, in part:
+      //   If type is not compatible with the type of the actual next argument
+      //   (as promoted according to the default argument promotions), the
+      //   behavior is undefined, except for the following cases:
+      //     - both types are pointers to qualified or unqualified versions of
+      //       compatible types;
+      //     - one type is a signed integer type, the other type is the
+      //       corresponding unsigned integer type, and the value is
+      //       representable in both types;
+      //     - one type is pointer to qualified or unqualified void and the
+      //       other is a pointer to a qualified or unqualified character type.
+      // Given that type compatibility is the primary requirement (ignoring
+      // qualifications), you would think we could call typesAreCompatible()
+      // directly to test this. However, in C++, that checks for *same type*,
+      // which causes false positives when passing an enumeration type to
+      // va_arg. Instead, get the underlying type of the enumeration and pass
+      // that.
+      QualType UnderlyingType = TInfo->getType();
+      if (const auto *ET = UnderlyingType->getAs<EnumType>())
+        UnderlyingType = ET->getDecl()->getIntegerType();
+      if (Context.typesAreCompatible(PromoteType, UnderlyingType,
+                                     /*CompareUnqualified*/ true))
         PromoteType = QualType();
+
+      // If the types are still not compatible, we need to test whether the
+      // promoted type and the underlying type are the same except for
+      // signedness. Ask the AST for the correctly corresponding type and see
+      // if that's compatible.
+      if (!PromoteType.isNull() &&
+          PromoteType->isUnsignedIntegerType() !=
+              UnderlyingType->isUnsignedIntegerType()) {
+        UnderlyingType =
+            UnderlyingType->isUnsignedIntegerType()
+                ? Context.getCorrespondingSignedType(UnderlyingType)
+                : Context.getCorrespondingUnsignedType(UnderlyingType);
+        if (Context.typesAreCompatible(PromoteType, UnderlyingType,
+                                       /*CompareUnqualified*/ true))
+          PromoteType = QualType();
+      }
     }
     if (TInfo->getType()->isSpecificBuiltinType(BuiltinType::Float))
       PromoteType = Context.DoubleTy;

clang/lib/Sema/SemaInit.cpp

@@ -3457,7 +3457,7 @@ LLVM_DUMP_METHOD void InitializedEntity::dump() const {
 void InitializationSequence::Step::Destroy() {
   switch (Kind) {
   case SK_ResolveAddressOfOverloadedFunction:
-  case SK_CastDerivedToBaseRValue:
+  case SK_CastDerivedToBasePRValue:
   case SK_CastDerivedToBaseXValue:
   case SK_CastDerivedToBaseLValue:
   case SK_BindReference:
@@ -3585,7 +3585,7 @@ void InitializationSequence::AddDerivedToBaseCastStep(QualType BaseType,
   Step S;
   switch (VK) {
   case VK_PRValue:
-    S.Kind = SK_CastDerivedToBaseRValue;
+    S.Kind = SK_CastDerivedToBasePRValue;
     break;
   case VK_XValue: S.Kind = SK_CastDerivedToBaseXValue; break;
   case VK_LValue: S.Kind = SK_CastDerivedToBaseLValue; break;
@@ -8107,7 +8107,7 @@ ExprResult InitializationSequence::Perform(Sema &S,
   // initializer.
   switch (Steps.front().Kind) {
   case SK_ResolveAddressOfOverloadedFunction:
-  case SK_CastDerivedToBaseRValue:
+  case SK_CastDerivedToBasePRValue:
   case SK_CastDerivedToBaseXValue:
   case SK_CastDerivedToBaseLValue:
   case SK_BindReference:
@@ -8192,7 +8192,7 @@ ExprResult InitializationSequence::Perform(Sema &S,
                                                  Step->Function.Function);
       break;
 
-    case SK_CastDerivedToBaseRValue:
+    case SK_CastDerivedToBasePRValue:
     case SK_CastDerivedToBaseXValue:
     case SK_CastDerivedToBaseLValue: {
       // We have a derived-to-base cast that produces either an rvalue or an
@@ -9628,8 +9628,8 @@ void InitializationSequence::dump(raw_ostream &OS) const {
       OS << "resolve address of overloaded function";
       break;
 
-    case SK_CastDerivedToBaseRValue:
-      OS << "derived-to-base (rvalue)";
+    case SK_CastDerivedToBasePRValue:
+      OS << "derived-to-base (prvalue)";
       break;
 
     case SK_CastDerivedToBaseXValue:

clang/test/Driver/cl-options.c

@@ -420,6 +420,7 @@
 // (/Zs is for syntax-only)
 // RUN: %clang_cl /Zs \
 // RUN:     /await \
+// RUN:     /await:strict \
 // RUN:     /constexpr:depth1000 /constexpr:backtrace1000 /constexpr:steps1000 \
 // RUN:     /AIfoo \
 // RUN:     /AI foo_does_not_exist \

clang/test/Lexer/cxx-features.cpp

@@ -98,8 +98,7 @@
 #error "wrong value for __cpp_modules"
 #endif
 
-#if check(using_enum, 0, 0, 0, 0, 0, 0)
-// FIXME: 201907 in C++20
+#if check(using_enum, 0, 0, 0, 0, 201907, 201907)
 #error "wrong value for __cpp_using_enum"
 #endif
 

clang/test/SemaCXX/varargs.cpp

@@ -1,5 +1,5 @@
-// RUN: %clang_cc1 -std=c++03 -verify %s
-// RUN: %clang_cc1 -std=c++11 -verify %s
+// RUN: %clang_cc1 -std=c++03 -Wno-c++11-extensions -triple i386-pc-unknown -verify %s
+// RUN: %clang_cc1 -std=c++11 -triple x86_64-apple-darwin9 -verify %s
 
 __builtin_va_list ap;
 
@@ -28,6 +28,33 @@ void record_context(int a, ...) {
   };
 }
 
+// Ensure the correct behavior for promotable type UB checking.
+void promotable(int a, ...) {
+  enum Unscoped1 { One = 0x7FFFFFFF };
+  (void)__builtin_va_arg(ap, Unscoped1); // ok
+
+  enum Unscoped2 { Two = 0xFFFFFFFF };
+  (void)__builtin_va_arg(ap, Unscoped2); // ok
+
+  enum class Scoped { Three };
+  (void)__builtin_va_arg(ap, Scoped); // ok
+
+  enum Fixed : int { Four };
+  (void)__builtin_va_arg(ap, Fixed); // ok
+
+  enum FixedSmall : char { Five };
+  (void)__builtin_va_arg(ap, FixedSmall); // expected-warning {{second argument to 'va_arg' is of promotable type 'FixedSmall'; this va_arg has undefined behavior because arguments will be promoted to 'int'}}
+
+  enum FixedLarge : long long { Six };
+  (void)__builtin_va_arg(ap, FixedLarge); // ok
+
+  // Ensure that qualifiers are ignored.
+  (void)__builtin_va_arg(ap, const volatile int);  // ok
+
+  // Ensure that signed vs unsigned doesn't matter either.
+  (void)__builtin_va_arg(ap, unsigned int);
+}
+
 #if __cplusplus >= 201103L
 // We used to have bugs identifying the correct enclosing function scope in a
 // lambda.