[LLDB] Add type summaries for MSVC STL strings

Author: Nerixyz

lldb/include/lldb/DataFormatters/StringPrinter.h

@@ -152,6 +152,21 @@ class StringPrinter {
   template <StringElementType element_type>
   static bool
   ReadBufferAndDumpToStream(const ReadBufferAndDumpToStreamOptions &options);
+
+  template <StringElementType element_type>
+  static constexpr uint64_t ElementByteSize() {
+    switch (element_type) {
+    case StringElementType::ASCII:
+    case StringElementType::UTF8:
+      return 1;
+    case StringElementType::UTF16:
+      return 2;
+    case StringElementType::UTF32:
+      return 3;
+    default:
+      return 0;
+    }
+  }
 };
 
 } // namespace formatters

lldb/packages/Python/lldbsuite/test/configuration.py

@@ -134,6 +134,8 @@
 libcxx_include_target_dir = None
 libcxx_library_dir = None
 
+target_triple = None
+
 # A plugin whose tests will be enabled, like intel-pt.
 enabled_plugins = []
 

lldb/packages/Python/lldbsuite/test/dotest.py

@@ -299,6 +299,8 @@ def parseOptionsAndInitTestdirs():
     configuration.libcxx_library_dir = args.libcxx_library_dir
     configuration.cmake_build_type = args.cmake_build_type.lower()
 
+    configuration.target_triple = args.target_triple
+
     if args.channels:
         lldbtest_config.channels = args.channels
 
@@ -831,6 +833,26 @@ def checkLibstdcxxSupport():
     configuration.skip_categories.append("libstdcxx")
 
 
+def canRunMsvcStlTests():
+    if "windows-msvc" in configuration.target_triple:
+        return True, "MSVC STL is present on *windows-msvc*"
+    return (
+        False,
+        f"Don't know how to build with MSVC's STL on {configuration.target_triple}",
+    )
+
+
+def checkMsvcStlSupport():
+    result, reason = canRunMsvcStlTests()
+    if result:
+        return  # msvcstl supported
+    if "msvcstl" in configuration.categories_list:
+        return  # msvcstl category explicitly requested, let it run.
+    if configuration.verbose:
+        print(f"msvcstl tests will not be run because: {reason}")
+    configuration.skip_categories.append("msvcstl")
+
+
 def canRunWatchpointTests():
     from lldbsuite.test import lldbplatformutil
 
@@ -1044,6 +1066,7 @@ def run_suite():
 
     checkLibcxxSupport()
     checkLibstdcxxSupport()
+    checkMsvcStlSupport()
     checkWatchpointSupport()
     checkDebugInfoSupport()
     checkDebugServerSupport()

lldb/packages/Python/lldbsuite/test/dotest_args.py

@@ -116,6 +116,12 @@ def create_parser():
             "The location of llvm tools used for testing (yaml2obj, FileCheck, etc.)."
         ),
     )
+    group.add_argument(
+        "--target-triple",
+        help=textwrap.dedent(
+            "The target triple the tests will run on (e.g. x86_64-pc-windows-msvc)."
+        ),
+    )
 
     # Test filtering options
     group = parser.add_argument_group("Test filtering options")

lldb/packages/Python/lldbsuite/test/test_categories.py

@@ -33,6 +33,7 @@
     "lldb-server": "Tests related to lldb-server",
     "lldb-dap": "Tests for the Debug Adapter Protocol with lldb-dap",
     "llgs": "Tests for the gdb-server functionality of lldb-server",
+    "msvcstl": "Test for MSVC STL data formatters",
     "pexpect": "Tests requiring the pexpect library to be available",
     "objc": "Tests related to the Objective-C programming language support",
     "pyapi": "Tests related to the Python API",

lldb/source/Plugins/Language/CPlusPlus/CMakeLists.txt

@@ -32,6 +32,7 @@ add_lldb_library(lldbPluginCPlusPlusLanguage PLUGIN
   LibStdcpp.cpp
   LibStdcppTuple.cpp
   LibStdcppUniquePointer.cpp
+  MsvcStl.cpp
   MSVCUndecoratedNameParser.cpp
 
   LINK_COMPONENTS

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

@@ -46,6 +46,7 @@
 #include "LibCxxVariant.h"
 #include "LibStdcpp.h"
 #include "MSVCUndecoratedNameParser.h"
+#include "MsvcStl.h"
 #include "lldb/lldb-enumerations.h"
 
 using namespace lldb;
@@ -1372,6 +1373,36 @@ static void LoadLibCxxFormatters(lldb::TypeCategoryImplSP cpp_category_sp) {
           "${var.__y_} ${var.__m_} ${var.__wdl_}")));
 }
 
+static void RegisterStdStringSummaryProvider(
+    const lldb::TypeCategoryImplSP &category_sp, llvm::StringRef string_ty,
+    llvm::StringRef char_ty, lldb::TypeSummaryImplSP summary_sp) {
+  auto makeSpecifier = [](llvm::StringRef name) {
+    return std::make_shared<lldb_private::TypeNameSpecifierImpl>(
+        name, eFormatterMatchExact);
+  };
+
+  category_sp->AddTypeSummary(makeSpecifier(string_ty), summary_sp);
+
+  // std::basic_string<char>
+  category_sp->AddTypeSummary(
+      makeSpecifier((llvm::Twine("std::basic_string<") + char_ty + ">").str()),
+      summary_sp);
+  // std::basic_string<char,std::char_traits<char>,std::allocator<char> >
+  category_sp->AddTypeSummary(
+      makeSpecifier((llvm::Twine("std::basic_string<") + char_ty +
+                     ",std::char_traits<" + char_ty + ">,std::allocator<" +
+                     char_ty + "> >")
+                        .str()),
+      summary_sp);
+  // std::basic_string<char, std::char_traits<char>, std::allocator<char> >
+  category_sp->AddTypeSummary(
+      makeSpecifier((llvm::Twine("std::basic_string<") + char_ty +
+                     ", std::char_traits<" + char_ty + ">, std::allocator<" +
+                     char_ty + "> >")
+                        .str()),
+      summary_sp);
+}
+
 static void LoadLibStdcppFormatters(lldb::TypeCategoryImplSP cpp_category_sp) {
   if (!cpp_category_sp)
     return;
@@ -1385,27 +1416,13 @@ static void LoadLibStdcppFormatters(lldb::TypeCategoryImplSP cpp_category_sp) {
       .SetShowMembersOneLiner(false)
       .SetHideItemNames(false);
 
-  lldb::TypeSummaryImplSP std_string_summary_sp(
-      new StringSummaryFormat(stl_summary_flags, "${var._M_dataplus._M_p}"));
-
   lldb::TypeSummaryImplSP cxx11_string_summary_sp(new CXXFunctionSummaryFormat(
       stl_summary_flags, LibStdcppStringSummaryProvider,
       "libstdc++ c++11 std::string summary provider"));
   lldb::TypeSummaryImplSP cxx11_wstring_summary_sp(new CXXFunctionSummaryFormat(
       stl_summary_flags, LibStdcppWStringSummaryProvider,
       "libstdc++ c++11 std::wstring summary provider"));
 
-  cpp_category_sp->AddTypeSummary("std::string", eFormatterMatchExact,
-                                  std_string_summary_sp);
-  cpp_category_sp->AddTypeSummary("std::basic_string<char>",
-                                  eFormatterMatchExact, std_string_summary_sp);
-  cpp_category_sp->AddTypeSummary(
-      "std::basic_string<char,std::char_traits<char>,std::allocator<char> >",
-      eFormatterMatchExact, std_string_summary_sp);
-  cpp_category_sp->AddTypeSummary(
-      "std::basic_string<char, std::char_traits<char>, std::allocator<char> >",
-      eFormatterMatchExact, std_string_summary_sp);
-
   cpp_category_sp->AddTypeSummary("std::__cxx11::string", eFormatterMatchExact,
                                   cxx11_string_summary_sp);
   cpp_category_sp->AddTypeSummary(
@@ -1418,23 +1435,6 @@ static void LoadLibStdcppFormatters(lldb::TypeCategoryImplSP cpp_category_sp) {
                                   eFormatterMatchExact,
                                   cxx11_string_summary_sp);
 
-  // making sure we force-pick the summary for printing wstring (_M_p is a
-  // wchar_t*)
-  lldb::TypeSummaryImplSP std_wstring_summary_sp(
-      new StringSummaryFormat(stl_summary_flags, "${var._M_dataplus._M_p%S}"));
-
-  cpp_category_sp->AddTypeSummary("std::wstring", eFormatterMatchExact,
-                                  std_wstring_summary_sp);
-  cpp_category_sp->AddTypeSummary("std::basic_string<wchar_t>",
-                                  eFormatterMatchExact, std_wstring_summary_sp);
-  cpp_category_sp->AddTypeSummary("std::basic_string<wchar_t,std::char_traits<"
-                                  "wchar_t>,std::allocator<wchar_t> >",
-                                  eFormatterMatchExact, std_wstring_summary_sp);
-  cpp_category_sp->AddTypeSummary(
-      "std::basic_string<wchar_t, std::char_traits<wchar_t>, "
-      "std::allocator<wchar_t> >",
-      eFormatterMatchExact, std_wstring_summary_sp);
-
   cpp_category_sp->AddTypeSummary("std::__cxx11::wstring", eFormatterMatchExact,
                                   cxx11_wstring_summary_sp);
   cpp_category_sp->AddTypeSummary(
@@ -1629,6 +1629,81 @@ static void LoadLibStdcppFormatters(lldb::TypeCategoryImplSP cpp_category_sp) {
                 "^std::optional<.+>(( )?&)?$", stl_summary_flags, true);
 }
 
+static void LoadCommonStlFormatters(lldb::TypeCategoryImplSP cpp_category_sp) {
+  if (!cpp_category_sp)
+    return;
+
+  TypeSummaryImpl::Flags stl_summary_flags;
+  stl_summary_flags.SetCascades(true)
+      .SetSkipPointers(false)
+      .SetSkipReferences(false)
+      .SetDontShowChildren(true)
+      .SetDontShowValue(false)
+      .SetShowMembersOneLiner(false)
+      .SetHideItemNames(false);
+  using StringElementType = StringPrinter::StringElementType;
+
+  RegisterStdStringSummaryProvider(
+      cpp_category_sp, "std::string", "char",
+      std::make_shared<CXXFunctionSummaryFormat>(
+          stl_summary_flags,
+          [](ValueObject &valobj, Stream &stream,
+             const TypeSummaryOptions &options) {
+            if (IsMsvcStdStringType(valobj))
+              return MsvcStlStringSummaryProvider<StringElementType::ASCII>(
+                  valobj, stream, options);
+            return LibStdcppPre11StringSummaryProvider(valobj, stream, options);
+          },
+          "MSVC STL/libstdc++ std::string summary provider"));
+  RegisterStdStringSummaryProvider(
+      cpp_category_sp, "std::wstring", "wchar_t",
+      std::make_shared<CXXFunctionSummaryFormat>(
+          stl_summary_flags,
+          [](ValueObject &valobj, Stream &stream,
+             const TypeSummaryOptions &options) {
+            if (IsMsvcStdStringType(valobj))
+              return MsvcStlWStringSummaryProvider(valobj, stream, options);
+            return LibStdcppPre11WStringSummaryProvider(valobj, stream,
+                                                        options);
+          },
+          "MSVC STL/libstdc++ std::wstring summary provider"));
+}
+
+static void LoadMsvcStlFormatters(lldb::TypeCategoryImplSP cpp_category_sp) {
+  if (!cpp_category_sp)
+    return;
+
+  TypeSummaryImpl::Flags stl_summary_flags;
+  stl_summary_flags.SetCascades(true)
+      .SetSkipPointers(false)
+      .SetSkipReferences(false)
+      .SetDontShowChildren(true)
+      .SetDontShowValue(false)
+      .SetShowMembersOneLiner(false)
+      .SetHideItemNames(false);
+
+  using StringElementType = StringPrinter::StringElementType;
+
+  RegisterStdStringSummaryProvider(
+      cpp_category_sp, "std::u8string", "char8_t",
+      std::make_shared<CXXFunctionSummaryFormat>(
+          stl_summary_flags,
+          MsvcStlStringSummaryProvider<StringElementType::UTF8>,
+          "MSVC STL std::u8string summary provider"));
+  RegisterStdStringSummaryProvider(
+      cpp_category_sp, "std::u16string", "char16_t",
+      std::make_shared<CXXFunctionSummaryFormat>(
+          stl_summary_flags,
+          MsvcStlStringSummaryProvider<StringElementType::UTF16>,
+          "MSVC STL std::u16string summary provider"));
+  RegisterStdStringSummaryProvider(
+      cpp_category_sp, "std::u32string", "char32_t",
+      std::make_shared<CXXFunctionSummaryFormat>(
+          stl_summary_flags,
+          MsvcStlStringSummaryProvider<StringElementType::UTF32>,
+          "MSVC STL std::u32string summary provider"));
+}
+
 static void LoadSystemFormatters(lldb::TypeCategoryImplSP cpp_category_sp) {
   if (!cpp_category_sp)
     return;
@@ -1743,6 +1818,8 @@ lldb::TypeCategoryImplSP CPlusPlusLanguage::GetFormatters() {
       // LLDB prioritizes the last loaded matching formatter.
       LoadLibCxxFormatters(g_category);
       LoadLibStdcppFormatters(g_category);
+      LoadMsvcStlFormatters(g_category);
+      LoadCommonStlFormatters(g_category);
       LoadSystemFormatters(g_category);
     }
   });

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

@@ -7,6 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "LibStdcpp.h"
+#include "CxxStringTypes.h"
 #include "LibCxx.h"
 
 #include "Plugins/TypeSystem/Clang/TypeSystemClang.h"
@@ -237,6 +238,43 @@ VectorIteratorSyntheticFrontEnd::GetIndexOfChildWithName(ConstString name) {
                                  name.AsCString());
 }
 
+bool lldb_private::formatters::LibStdcppPre11StringSummaryProvider(
+    ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
+  ValueObjectSP dataplus = valobj.GetChildMemberWithName("_M_dataplus");
+  if (!dataplus)
+    return false;
+  ValueObjectSP ptr = dataplus->GetChildMemberWithName("_M_p");
+  if (!ptr)
+    return false;
+
+  Address valobj_addr = valobj.GetPointerValue().address;
+  if (!valobj_addr.IsValid())
+    return false;
+
+  StringPrinter::ReadStringAndDumpToStreamOptions printer_opts(valobj);
+  printer_opts.SetLocation(valobj_addr);
+  printer_opts.SetTargetSP(valobj.GetTargetSP());
+  printer_opts.SetStream(&stream);
+
+  if (!StringPrinter::ReadStringAndDumpToStream<
+          StringPrinter::StringElementType::ASCII>(printer_opts))
+    stream.Printf("Summary Unavailable");
+
+  return true;
+}
+
+bool lldb_private::formatters::LibStdcppPre11WStringSummaryProvider(
+    ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
+  ValueObjectSP dataplus = valobj.GetChildMemberWithName("_M_dataplus");
+  if (!dataplus)
+    return false;
+  ValueObjectSP ptr = dataplus->GetChildMemberWithName("_M_p");
+  if (!ptr)
+    return false;
+
+  return WCharStringSummaryProvider(*ptr, stream, options);
+}
+
 bool lldb_private::formatters::LibStdcppStringSummaryProvider(
     ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
   const bool scalar_is_load_addr = true;

lldb/source/Plugins/Language/CPlusPlus/LibStdcpp.h

@@ -16,6 +16,14 @@
 
 namespace lldb_private {
 namespace formatters {
+bool LibStdcppPre11StringSummaryProvider(
+    ValueObject &valobj, Stream &stream,
+    const TypeSummaryOptions &options); // libstdc++ pre-c++11 std::string
+
+bool LibStdcppPre11WStringSummaryProvider(
+    ValueObject &valobj, Stream &stream,
+    const TypeSummaryOptions &options); // libstdc++ pre-c++11 std::wstring
+
 bool LibStdcppStringSummaryProvider(
     ValueObject &valobj, Stream &stream,
     const TypeSummaryOptions &options); // libcstdc++ c++11 std::string