[LLDB] Add formatters for MSVC STL std::deque (#150097)

This PR adds synthetic children for std::deque from MSVC's STL.

Similar to libstdc++ and libc++, the elements are in a `T**`, so we need
to "subscript" twice. The [NatVis for
deque](https://github.com/microsoft/STL/blob/313964b78a8fd5a52e7965e13781f735bcce13c5/stl/debugger/STL.natvis#L1103-L1112)
uses `_EEN_DS` which contains the block size. We can't access this, but
we can access the [constexpr
`_Block_size`](https://github.com/microsoft/STL/blob/313964b78a8fd5a52e7965e13781f735bcce13c5/stl/inc/deque#L641).

Towards #24834.

1 files changed, 21 insertions, 11 deletions

diff --git a/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/deque/TestDataFormatterGenericDeque.py b/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/deque/TestDataFormatterGenericDeque.py
index f52f6f7ec3ff..2332eff7b10d 100644
--- a/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/deque/TestDataFormatterGenericDeque.py
+++ b/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/deque/TestDataFormatterGenericDeque.py
@@ -3,9 +3,6 @@ from lldbsuite.test.decorators import *
 from lldbsuite.test.lldbtest import *
 from lldbsuite.test import lldbutil
 
-USE_LIBSTDCPP = "USE_LIBSTDCPP"
-USE_LIBCPP = "USE_LIBCPP"
-
 
 class GenericDequeDataFormatterTestCase(TestBase):
     def findVariable(self, name):
@@ -56,8 +53,7 @@ class GenericDequeDataFormatterTestCase(TestBase):
             ],
         )
 
-    def do_test(self, stdlib_type):
-        self.build(dictionary={stdlib_type: "1"})
+    def do_test(self):
         (_, process, _, bkpt) = lldbutil.run_to_source_breakpoint(
             self, "break here", lldb.SBFileSpec("main.cpp")
         )
@@ -135,15 +131,22 @@ class GenericDequeDataFormatterTestCase(TestBase):
 
     @add_test_categories(["libstdcxx"])
     def test_libstdcpp(self):
-        self.do_test(USE_LIBSTDCPP)
+        self.build(dictionary={"USE_LIBSTDCPP": 1})
+        self.do_test()
 
     @add_test_categories(["libc++"])
     def test_libcpp(self):
-        self.do_test(USE_LIBCPP)
+        self.build(dictionary={"USE_LIBCPP": 1})
+        self.do_test()
+
+    @add_test_categories(["msvcstl"])
+    def test_msvcstl(self):
+        # No flags, because the "msvcstl" category checks that the MSVC STL is used by default.
+        self.build()
+        self.do_test()
 
-    def do_test_ref_and_ptr(self, stdlib_type: str):
+    def do_test_ref_and_ptr(self):
         """Test formatting of std::deque& and std::deque*"""
-        self.build(dictionary={stdlib_type: "1"})
         (self.target, process, thread, bkpt) = lldbutil.run_to_source_breakpoint(
             self, "stop here", lldb.SBFileSpec("main.cpp", False)
         )
@@ -157,8 +160,15 @@ class GenericDequeDataFormatterTestCase(TestBase):
 
     @add_test_categories(["libstdcxx"])
     def test_libstdcpp_ref_and_ptr(self):
-        self.do_test_ref_and_ptr(USE_LIBSTDCPP)
+        self.build(dictionary={"USE_LIBSTDCPP": 1})
+        self.do_test_ref_and_ptr()
 
     @add_test_categories(["libc++"])
     def test_libcpp_ref_and_ptr(self):
-        self.do_test_ref_and_ptr(USE_LIBCPP)
+        self.build(dictionary={"USE_LIBCPP": 1})
+        self.do_test_ref_and_ptr()
+
+    @add_test_categories(["msvcstl"])
+    def test_msvcstl_ref_and_ptr(self):
+        self.build()
+        self.do_test_ref_and_ptr()