[lldb] Fix TypeSystemClang::GetBasicTypeEnumeration for 128-bit int types

lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp

@@ -849,8 +849,20 @@ lldb::BasicType TypeSystemClang::GetBasicTypeEnumeration(llvm::StringRef name) {
       {"unsigned long long int", eBasicTypeUnsignedLongLong},
 
       // "int128"
+      //
+      // The following two lines are here only
+      // for the sake of backward-compatibility.
+      // Neither "__int128_t", nor "__uint128_t" are basic-types.
+      // They are typedefs.
       {"__int128_t", eBasicTypeInt128},
       {"__uint128_t", eBasicTypeUnsignedInt128},
+      // In order to be consistent with:
+      // - gcc's C programming language extension related to 128-bit integers
+      //   https://gcc.gnu.org/onlinedocs/gcc/_005f_005fint128.html
+      // - the "BuiltinType::getName" method in LLVM
+      // the following two lines must be present:
+      {"__int128", eBasicTypeInt128},
+      {"unsigned __int128", eBasicTypeUnsignedInt128},
 
       // "bool"
       {"bool", eBasicTypeBool},

lldb/test/API/python_api/sbtype_basic_type/TestSBTypeBasicType.py

@@ -5,11 +5,14 @@
 
 
 class TestCase(TestBase):
-    def test(self):
-        """Test that SBType.GetBasicType unwraps typedefs."""
+    def setUp(self):
+        TestBase.setUp(self)
         self.build()
         lldbutil.run_to_source_breakpoint(self, "return", lldb.SBFileSpec("main.cpp"))
 
+    def testTypedefUnwrapping(self):
+        """Test that SBType.GetBasicType unwraps typedefs."""
+
         a = self.frame().FindVariable("a")
         self.assertTrue(a)
 
@@ -28,3 +31,8 @@ def test(self):
         self.assertEqual(b.GetType().GetBasicType(), int_basic_type)
         self.assertEqual(c.GetType().GetBasicType(), int_basic_type)
         self.assertEqual(d.GetType().GetBasicType(), int_basic_type)
+
+    def testBasicTypeSize(self):
+        """Check the size of the chosen basic types."""
+        self.assertEqual(self.target().FindFirstType("__int128").size, 16)
+        self.assertEqual(self.target().FindFirstType("unsigned __int128").size, 16)

lldb/unittests/Symbol/TestTypeSystemClang.cpp

@@ -162,6 +162,9 @@ TEST_F(TestTypeSystemClang, TestGetBasicTypeFromName) {
   EXPECT_EQ(GetBasicQualType(eBasicTypeInt128), GetBasicQualType("__int128_t"));
   EXPECT_EQ(GetBasicQualType(eBasicTypeUnsignedInt128),
             GetBasicQualType("__uint128_t"));
+  EXPECT_EQ(GetBasicQualType(eBasicTypeInt128), GetBasicQualType("__int128"));
+  EXPECT_EQ(GetBasicQualType(eBasicTypeUnsignedInt128),
+            GetBasicQualType("unsigned __int128"));
   EXPECT_EQ(GetBasicQualType(eBasicTypeVoid), GetBasicQualType("void"));
   EXPECT_EQ(GetBasicQualType(eBasicTypeBool), GetBasicQualType("bool"));
   EXPECT_EQ(GetBasicQualType(eBasicTypeFloat), GetBasicQualType("float"));