Make __builtin_types_compatible_p more like GCC's

GCC ignore qualifiers on array types. Since we seem to have this
function primarily for GCC compatibility, we should try to match that
behavior.

This also adds a few more test-cases __builtin_types_compatible_p,
which were inspired by GCC's documentation on the builtin.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@315951 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp
index 17aa8847e03d82c0c3036bd3ed5f1acc838360b1..7f5b792e8c4923561d0bf0a5363fc707b17a9c84 100644 (file)
--- a/lib/Sema/SemaExprCXX.cpp
+++ b/lib/Sema/SemaExprCXX.cpp
@@ -4824,9 +4824,13 @@ static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT,
   }
   case BTT_IsSame:
     return Self.Context.hasSameType(LhsT, RhsT);
-  case BTT_TypeCompatible:
-    return Self.Context.typesAreCompatible(LhsT.getUnqualifiedType(),
-                                           RhsT.getUnqualifiedType());
+  case BTT_TypeCompatible: {
+    // GCC ignores cv-qualifiers on arrays for this builtin.
+    Qualifiers LhsQuals, RhsQuals;
+    QualType Lhs = Self.getASTContext().getUnqualifiedArrayType(LhsT, LhsQuals);
+    QualType Rhs = Self.getASTContext().getUnqualifiedArrayType(RhsT, RhsQuals);
+    return Self.Context.typesAreCompatible(Lhs, Rhs);
+  }
   case BTT_IsConvertible:
   case BTT_IsConvertibleTo: {
     // C++0x [meta.rel]p4:

diff --git a/test/Parser/builtin_types_compatible.c b/test/Parser/builtin_types_compatible.c
index ac81e7b08dc95e97a8cecd291fd7c06f6d98da70..d967a7023a490100b65ef65efbfc2c29e732bee7 100644 (file)
--- a/test/Parser/builtin_types_compatible.c
+++ b/test/Parser/builtin_types_compatible.c
@@ -41,3 +41,20 @@ static void test()
 
 }
 
+enum E1 { E1Foo };
+enum E2 { E2Foo };
+
+static void testGccCompatibility() {
+  _Static_assert(__builtin_types_compatible_p(const volatile int, int), "");
+  _Static_assert(__builtin_types_compatible_p(int[5], int[]), "");
+  _Static_assert(!__builtin_types_compatible_p(int[5], int[4]), "");
+  _Static_assert(!__builtin_types_compatible_p(int *, int **), "");
+  _Static_assert(!__builtin_types_compatible_p(const int *, int *), "");
+  _Static_assert(!__builtin_types_compatible_p(enum E1, enum E2), "");
+
+  // GCC's __builtin_types_compatible_p ignores qualifiers on arrays.
+  _Static_assert(__builtin_types_compatible_p(const int[4], int[4]), "");
+  _Static_assert(__builtin_types_compatible_p(int[4], const int[4]), "");
+  _Static_assert(__builtin_types_compatible_p(const int[5][4], int[][4]), "");
+  _Static_assert(!__builtin_types_compatible_p(const int(*)[], int(*)[]), "");
+}