[lldb][test] Combine libstdc++ and libc++ tuple tests into generic test (#147139)

This combines the libc++ and libstdc++ test cases. The main difference
was that the libstdcpp tests had some tuple indexing tests that libc++
didn't have.

The libstdc++ formatter didn't support size summaries for std::tuple. So
I added a `ContainerSizeSummaryProvider` for it (like we do for libc++).
Additionally, the synthetic frontend would only apply to non-empty
tuples, so I adjusted the regex to match empty ones too. We do this for
libc++ already.

Split out from #146740

Author: Michael137

lldb/source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp

@@ -1504,6 +1504,10 @@ static void LoadLibStdcppFormatters(lldb::TypeCategoryImplSP cpp_category_sp) {
                 "^std::((__debug::)?|(__cxx11::)?)list<.+>(( )?&)?$",
                 stl_summary_flags, true);
 
+  AddCXXSummary(cpp_category_sp, ContainerSizeSummaryProvider,
+                "libstdc++ std::tuple summary provider",
+                "^std::tuple<.*>(( )?&)?$", stl_summary_flags, true);
+
   cpp_category_sp->AddTypeSummary(
       "^std::((__debug::)?|(__cxx11::)?)forward_list<.+>(( )?&)?$",
       eFormatterMatchRegex,
@@ -1546,7 +1550,7 @@ static void LoadLibStdcppFormatters(lldb::TypeCategoryImplSP cpp_category_sp) {
   AddCXXSynthetic(
       cpp_category_sp,
       lldb_private::formatters::LibStdcppTupleSyntheticFrontEndCreator,
-      "std::tuple synthetic children", "^std::tuple<.+>(( )?&)?$",
+      "std::tuple synthetic children", "^std::tuple<.*>(( )?&)?$",
       stl_synth_flags, true);
 
   static constexpr const char *const libstdcpp_std_coroutine_handle_regex =

lldb/test/API/functionalities/data-formatter/data-formatter-stl/libcxx/tuple/Makefile renamed to lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/tuple/Makefile

@@ -1,4 +1,3 @@
 CXX_SOURCES := main.cpp
 
-USE_LIBCPP := 1
 include Makefile.rules

lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/tuple/TestDataFormatterStdTuple.py

@@ -0,0 +1,76 @@
+"""
+Test lldb data formatter subsystem.
+"""
+
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+
+class TestDataFormatterStdTuple(TestBase):
+    def setUp(self):
+        TestBase.setUp(self)
+        self.line = line_number("main.cpp", "// break here")
+        self.namespace = "std"
+
+    def do_test(self):
+        """Test that std::tuple is displayed correctly"""
+        lldbutil.run_to_source_breakpoint(
+            self, "// break here", lldb.SBFileSpec("main.cpp", False)
+        )
+
+        tuple_name = self.namespace + "::tuple"
+        self.expect("frame variable empty", substrs=[tuple_name, "size=0", "{}"])
+
+        self.expect(
+            "frame variable one_elt",
+            substrs=[tuple_name, "size=1", "{", "[0] = 47", "}"],
+        )
+
+        self.expect(
+            "frame variable three_elts",
+            substrs=[
+                tuple_name,
+                "size=3",
+                "{",
+                "[0] = 1",
+                "[1] = 47",
+                '[2] = "foo"',
+                "}",
+            ],
+        )
+
+        frame = self.frame()
+        self.assertTrue(frame.IsValid())
+
+        self.assertEqual(
+            47, frame.GetValueForVariablePath("one_elt[0]").GetValueAsUnsigned()
+        )
+        self.assertFalse(frame.GetValueForVariablePath("one_elt[1]").IsValid())
+
+        self.assertEqual(
+            '"foobar"', frame.GetValueForVariablePath("string_elt[0]").GetSummary()
+        )
+        self.assertFalse(frame.GetValueForVariablePath("string_elt[1]").IsValid())
+
+        self.assertEqual(
+            1, frame.GetValueForVariablePath("three_elts[0]").GetValueAsUnsigned()
+        )
+        self.assertEqual(
+            47, frame.GetValueForVariablePath("three_elts[1]").GetValueAsUnsigned()
+        )
+        self.assertEqual(
+            '"foo"', frame.GetValueForVariablePath("three_elts[2]").GetSummary()
+        )
+        self.assertFalse(frame.GetValueForVariablePath("three_elts[3]").IsValid())
+
+    @add_test_categories(["libc++"])
+    def test_libcxx(self):
+        self.build(dictionary={"USE_LIBCPP": 1})
+        self.do_test()
+
+    @add_test_categories(["libstdcxx"])
+    def test_libstdcxx(self):
+        self.build(dictionary={"USE_LIBSTDCPP": 1})
+        self.do_test()

lldb/test/API/functionalities/data-formatter/data-formatter-stl/libcxx/tuple/main.cpp renamed to lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/tuple/main.cpp

@@ -1,9 +1,10 @@
-#include <tuple>
 #include <string>
+#include <tuple>
 
 int main() {
   std::tuple<> empty;
   std::tuple<int> one_elt{47};
+  std::tuple<std::string> string_elt{"foobar"};
   std::tuple<int, long, std::string> three_elts{1, 47l, "foo"};
   return 0; // break here
 }