[Demangling] Refactor Demangler range tracking by charles-zablit · Pull Request #140762 · llvm/llvm-project

charles-zablit · 2025-05-20T16:48:51Z

This PR is a subset of the commits made in swiftlang#10710.

The most notable change is the addition of PrefixRange and SuffixRange which are a catch-all to track anything after or before a function's demangled name. In the case of Swift, this allows to add support for name highlighting without having to track the range of the scope and specifiers of a function (this will come in another PR).

llvmbot · 2025-05-20T16:49:27Z

@llvm/pr-subscribers-lldb

Author: Charles Zablit (charles-zablit)

Changes

This PR is a subset of the commits made in swiftlang#10710.

The most notable change is the addition of PrefixRange and SuffixRange which are a catch-all to track anything after or before a function's demangled name. In the case of Swift, this allows to add support for name highlighting without having to track the range of the scope and specifiers of a function (this will come in another PR).

Full diff: https://github.com/llvm/llvm-project/pull/140762.diff

7 Files Affected:

(modified) lldb/include/lldb/Core/DemangledNameInfo.h (+17-1)
(modified) lldb/include/lldb/Core/FormatEntity.h (+1)
(modified) lldb/source/Core/FormatEntity.cpp (+3)
(modified) lldb/source/Core/Mangled.cpp (+2)
(modified) lldb/source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp (+2-2)
(modified) lldb/unittests/Core/CMakeLists.txt (+1-1)
(renamed) lldb/unittests/Core/ItaniumMangledTest.cpp (+7-6)

diff --git a/lldb/include/lldb/Core/DemangledNameInfo.h b/lldb/include/lldb/Core/DemangledNameInfo.h
index 11d3bb58871b8..76cf8908fcbe6 100644
--- a/lldb/include/lldb/Core/DemangledNameInfo.h
+++ b/lldb/include/lldb/Core/DemangledNameInfo.h
@@ -39,7 +39,7 @@ struct DemangledNameInfo {
   /// \endcode
   std::pair<size_t, size_t> ScopeRange;
 
-  /// Indicates the [start, end) of the function argument lits.
+  /// Indicates the [start, end) of the function argument list.
   /// E.g.,
   /// \code{.cpp}
   ///    int (*getFunc<float>(float, double))(int, int)
@@ -59,11 +59,27 @@ struct DemangledNameInfo {
   /// \endcode
   std::pair<size_t, size_t> QualifiersRange;
 
+  /// Indicates the [start, end) of the function's prefix. This is a
+  /// catch-all range for anything that is not tracked by the rest of
+  /// the pairs.
+  std::pair<size_t, size_t> PrefixRange;
+
+  /// Indicates the [start, end) of the function's suffix. This is a
+  /// catch-all range for anything that is not tracked by the rest of
+  /// the pairs.
+  std::pair<size_t, size_t> SuffixRange;
+
   /// Returns \c true if this object holds a valid basename range.
   bool hasBasename() const {
     return BasenameRange.second > BasenameRange.first &&
            BasenameRange.second > 0;
   }
+
+  /// Returns \c true if this object holds a valid arguments range.
+  bool hasArguments() const {
+    return ArgumentsRange.second > ArgumentsRange.first &&
+           ArgumentsRange.second > 0;
+  }
 };
 
 /// An OutputBuffer which keeps a record of where certain parts of a
diff --git a/lldb/include/lldb/Core/FormatEntity.h b/lldb/include/lldb/Core/FormatEntity.h
index 6acf6fbe43239..1aed3c6ff9e9d 100644
--- a/lldb/include/lldb/Core/FormatEntity.h
+++ b/lldb/include/lldb/Core/FormatEntity.h
@@ -88,6 +88,7 @@ struct Entry {
     FunctionNameWithArgs,
     FunctionNameNoArgs,
     FunctionMangledName,
+    FunctionPrefix,
     FunctionScope,
     FunctionBasename,
     FunctionTemplateArguments,
diff --git a/lldb/source/Core/FormatEntity.cpp b/lldb/source/Core/FormatEntity.cpp
index 4f2d39873c7fb..4dcfa43a7bb04 100644
--- a/lldb/source/Core/FormatEntity.cpp
+++ b/lldb/source/Core/FormatEntity.cpp
@@ -124,6 +124,7 @@ constexpr Definition g_function_child_entries[] = {
     Definition("initial-function", EntryType::FunctionInitial),
     Definition("changed", EntryType::FunctionChanged),
     Definition("is-optimized", EntryType::FunctionIsOptimized),
+    Definition("prefix", EntryType::FunctionPrefix),
     Definition("scope", EntryType::FunctionScope),
     Definition("basename", EntryType::FunctionBasename),
     Definition("template-arguments", EntryType::FunctionTemplateArguments),
@@ -385,6 +386,7 @@ const char *FormatEntity::Entry::TypeToCString(Type t) {
     ENUM_TO_CSTR(FunctionNameWithArgs);
     ENUM_TO_CSTR(FunctionNameNoArgs);
     ENUM_TO_CSTR(FunctionMangledName);
+    ENUM_TO_CSTR(FunctionPrefix);
     ENUM_TO_CSTR(FunctionScope);
     ENUM_TO_CSTR(FunctionBasename);
     ENUM_TO_CSTR(FunctionTemplateArguments);
@@ -1835,6 +1837,7 @@ bool FormatEntity::Format(const Entry &entry, Stream &s,
     return true;
   }
 
+  case Entry::Type::FunctionPrefix:
   case Entry::Type::FunctionScope:
   case Entry::Type::FunctionBasename:
   case Entry::Type::FunctionTemplateArguments:
diff --git a/lldb/source/Core/Mangled.cpp b/lldb/source/Core/Mangled.cpp
index ce4db4e0daa8b..e6f7d198d7316 100644
--- a/lldb/source/Core/Mangled.cpp
+++ b/lldb/source/Core/Mangled.cpp
@@ -172,6 +172,8 @@ GetItaniumDemangledStr(const char *M) {
 
     TrackingOutputBuffer OB(demangled_cstr, demangled_size);
     demangled_cstr = ipd.finishDemangle(&OB);
+    OB.NameInfo.SuffixRange.first = OB.NameInfo.QualifiersRange.second;
+    OB.NameInfo.SuffixRange.second = std::string(demangled_cstr).length();
     info = std::move(OB.NameInfo);
 
     assert(demangled_cstr &&
diff --git a/lldb/source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp b/lldb/source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp
index 542f13bef23e7..f45b4fb816b3b 100644
--- a/lldb/source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp
+++ b/lldb/source/Plugins/Language/CPlusPlus/CPlusPlusLanguage.cpp
@@ -401,8 +401,8 @@ GetDemangledFunctionSuffix(const SymbolContext &sc) {
   if (!info->hasBasename())
     return std::nullopt;
 
-  return demangled_name.slice(info->QualifiersRange.second,
-                              llvm::StringRef::npos);
+  return demangled_name.slice(info->SuffixRange.first,
+                              info->SuffixRange.second);
 }
 
 static bool PrintDemangledArgumentList(Stream &s, const SymbolContext &sc) {
diff --git a/lldb/unittests/Core/CMakeLists.txt b/lldb/unittests/Core/CMakeLists.txt
index 97268b3dbf8f8..234eb43b95257 100644
--- a/lldb/unittests/Core/CMakeLists.txt
+++ b/lldb/unittests/Core/CMakeLists.txt
@@ -6,7 +6,7 @@ add_lldb_unittest(LLDBCoreTests
   DumpDataExtractorTest.cpp
   DumpRegisterInfoTest.cpp
   FormatEntityTest.cpp
-  MangledTest.cpp
+  ItaniumMangledTest.cpp
   ModuleSpecTest.cpp
   PluginManagerTest.cpp
   ProgressReportTest.cpp
diff --git a/lldb/unittests/Core/MangledTest.cpp b/lldb/unittests/Core/ItaniumMangledTest.cpp
similarity index 98%
rename from lldb/unittests/Core/MangledTest.cpp
rename to lldb/unittests/Core/ItaniumMangledTest.cpp
index 44651eb94c23b..fef2b14af0948 100644
--- a/lldb/unittests/Core/MangledTest.cpp
+++ b/lldb/unittests/Core/ItaniumMangledTest.cpp
@@ -1,4 +1,4 @@
-//===-- MangledTest.cpp ---------------------------------------------------===//
+//===-- ItaniumMangledTest.cpp --------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -401,7 +401,7 @@ TEST(MangledTest, DemangledNameInfo_SetValue) {
   EXPECT_FALSE(mangled.GetDemangledInfo()->hasBasename());
 }
 
-struct DemanglingPartsTestCase {
+struct ItaniumDemanglingPartsTestCase {
   const char *mangled;
   DemangledNameInfo expected_info;
   std::string_view basename;
@@ -410,7 +410,7 @@ struct DemanglingPartsTestCase {
   bool valid_basename = true;
 };
 
-DemanglingPartsTestCase g_demangling_parts_test_cases[] = {
+ItaniumDemanglingPartsTestCase g_demangling_itanium_parts_test_cases[] = {
     // clang-format off
    { "_ZNVKO3BarIN2ns3QuxIiEEE1CIPFi3FooIS_IiES6_EEE6methodIS6_EENS5_IT_SC_E5InnerIiEESD_SD_",
      { /*.BasenameRange=*/{92, 98}, /*.ScopeRange=*/{36, 92}, /*.ArgumentsRange=*/{ 108, 158 },
@@ -555,7 +555,7 @@ DemanglingPartsTestCase g_demangling_parts_test_cases[] = {
 };
 
 struct DemanglingPartsTestFixture
-    : public ::testing::TestWithParam<DemanglingPartsTestCase> {};
+    : public ::testing::TestWithParam<ItaniumDemanglingPartsTestCase> {};
 
 namespace {
 class TestAllocator {
@@ -608,5 +608,6 @@ TEST_P(DemanglingPartsTestFixture, DemanglingParts) {
   std::free(OB.getBuffer());
 }
 
-INSTANTIATE_TEST_SUITE_P(DemanglingPartsTests, DemanglingPartsTestFixture,
-                         ::testing::ValuesIn(g_demangling_parts_test_cases));
+INSTANTIATE_TEST_SUITE_P(
+    DemanglingPartsTests, DemanglingPartsTestFixture,
+    ::testing::ValuesIn(g_demangling_itanium_parts_test_cases));

Michael137 · 2025-05-21T10:44:15Z

lldb/include/lldb/Core/DemangledNameInfo.h

  bool hasBasename() const {
-    return BasenameRange.second > BasenameRange.first &&
-           BasenameRange.second > 0;
+    return BasenameRange.second > BasenameRange.first;


Can you elaborate why this was needed?

It was not needed but since I added the hasArguments method I wanted to remove the redundant >0 check.

Since the start and end range are unsigned, if end > start, then end is always greater than 0, which is why I removed the second check. I might be missing something.

Michael137 · 2025-05-21T10:44:29Z

lldb/include/lldb/Core/DemangledNameInfo.h

+  }
+
+  /// Returns \c true if this object holds a valid arguments range.
+  bool hasArguments() const {


This seems unused?

Yes, it's only used in the Apple fork, I have removed the change now.

Michael137 · 2025-05-21T10:45:15Z

lldb/include/lldb/Core/FormatEntity.h

    FunctionNameWithArgs,
    FunctionNameNoArgs,
    FunctionMangledName,
+    FunctionPrefix,


If we add a new variable here we will need to update the documentation under lldb/docs/use/formatting.rst

Fixed, thanks 👍

Michael137 · 2025-05-21T10:46:13Z

lldb/unittests/Core/CMakeLists.txt

  DumpRegisterInfoTest.cpp
  FormatEntityTest.cpp
-  MangledTest.cpp
+  ItaniumMangledTest.cpp


I don't mind renaming the file but there are already swift mangling tests in this file, so ItaniumMangled isn't quite correct. What's the motivation for the rename?

The rename was to separate the Swift tests from the Itanium tests. But as you said, it does not make much sense here. I will instead rename the tests to SwiftTests in the Apple fork.

Michael137 · 2025-05-27T17:14:40Z

lldb/unittests/Core/MangledTest.cpp

@@ -320,293 +319,3 @@ TEST(MangledTest, NameIndexes_FindFunctionSymbols) {
  EXPECT_EQ(0, Count("undemangable", eFunctionNameTypeBase));
  EXPECT_EQ(0, Count("undemangable", eFunctionNameTypeMethod));
 }


Did something go wrong with renaming the test back?

Michael137

Generally makes sense

But lets add a test to confirm that no plugin currently handles the new FunctionPrefix variable (see e.g., lldb/test/Shell/Settings/TestFrameFormatFunctionBasenameObjC.test)

charles-zablit · 2025-05-27T17:16:44Z

But lets add a test to confirm that no plugin currently handles the new FunctionPrefix variable

Sorry I forgot about the test, will add it 👍

lldb/source/Core/Mangled.cpp

lldb/docs/use/formatting.rst

Co-authored-by: Michael Buch <michaelbuch12@gmail.com>

Michael137 · 2025-05-28T13:25:52Z

Getting following warning with this patch:

/Users/jonas/Git/llvm-worktrees/llvm-project/lldb/unittests/Core/MangledTest.cpp:417:40: warning: missing field 'PrefixRange' initializer [-Wmissing-field-initializers]
  417 |        /*.QualifiersRange=*/{158, 176} },                                                                                                             
      |                                        ^                                                                                                              
/Users/jonas/Git/llvm-worktrees/llvm-project/lldb/unittests/Core/MangledTest.cpp:423:122: warning: missing field 'PrefixRange' initializer [-Wmissing-field-initializers]
  423 |      { /*.BasenameRange=*/{6, 13}, /*.ScopeRange=*/{6, 6}, /*.ArgumentsRange=*/{ 20, 27 }, /*.QualifiersRange=*/{38, 38} },                           
      |                                                                                                                          ^                            
/Users/jonas/Git/llvm-worktrees/llvm-project/lldb/unittests/Core/MangledTest.cpp:430:38: warning: missing field 'PrefixRange' initializer [-Wmissing-field-initializers]
  430 |        /*.QualifiersRange=*/{12, 12} },                                                                                                               
      |                                      ^                                                                                                                
/Users/jonas/Git/llvm-worktrees/llvm-project/lldb/unittests/Core/MangledTest.cpp:437:38: warning: missing field 'PrefixRange' initializer [-Wmissing-field-initializers]
  437 |        /*.QualifiersRange=*/{58, 58} },                                                                                                               
      |                                      ^                                                                                                                
/Users/jonas/Git/llvm-worktrees/llvm-project/lldb/unittests/Core/MangledTest.cpp:444:38: warning: missing field 'PrefixRange' initializer [-Wmissing-field-initializers]
  444 |        /*.QualifiersRange=*/{79, 79} },                                                                                                               
      |                                      ^                                                                                                                
/Users/jonas/Git/llvm-worktrees/llvm-project/lldb/unittests/Core/MangledTest.cpp:451:40: warning: missing field 'PrefixRange' initializer [-Wmissing-field-initializers]
  451 |        /*.QualifiersRange=*/{168, 168} },                                                                                                             
      |                                        ^

when compiling the unit-tests.

Could you add the missing initializers to the test? I think you can just add a default value so you don't need to touch every test-case

charles-zablit · 2025-05-28T15:21:35Z

Could you add the missing initializers to the test? I think you can just add a default value so you don't need to touch every test-case

Sorry about that, fixed it with explicit default values in #141790.

…rning (#141790) #140762 introduces some compilation warnings in `lldb/unittests/Core/MangledTest.cpp`. This patch adds explicit default initialization to `DemangledNameInfo` to suppress those warnings. We only had the default initialization values to `PrefixRange` and `SuffixRange` because they are the only _optional_ fields of the structure.

…o remove warning (#141790) llvm/llvm-project#140762 introduces some compilation warnings in `lldb/unittests/Core/MangledTest.cpp`. This patch adds explicit default initialization to `DemangledNameInfo` to suppress those warnings. We only had the default initialization values to `PrefixRange` and `SuffixRange` because they are the only _optional_ fields of the structure.

This PR is a subset of the commits made in #10710. The most notable change is the addition of `PrefixRange` and `SuffixRange` which are a catch-all to track anything after or before a function's demangled name. In the case of Swift, this allows to add support for name highlighting without having to track the range of the scope and specifiers of a function (this will come in another PR).

…rning (llvm#141790) llvm#140762 introduces some compilation warnings in `lldb/unittests/Core/MangledTest.cpp`. This patch adds explicit default initialization to `DemangledNameInfo` to suppress those warnings. We only had the default initialization values to `PrefixRange` and `SuffixRange` because they are the only _optional_ fields of the structure.

* [Demangling] Refactor Demangler range tracking (llvm#140762) This PR is a subset of the commits made in #10710. The most notable change is the addition of `PrefixRange` and `SuffixRange` which are a catch-all to track anything after or before a function's demangled name. In the case of Swift, this allows to add support for name highlighting without having to track the range of the scope and specifiers of a function (this will come in another PR). * add explicit default initialization to DemangledNameInfo to remove warning (llvm#141790) llvm#140762 introduces some compilation warnings in `lldb/unittests/Core/MangledTest.cpp`. This patch adds explicit default initialization to `DemangledNameInfo` to suppress those warnings. We only had the default initialization values to `PrefixRange` and `SuffixRange` because they are the only _optional_ fields of the structure.

refactor demangler range tracking

cc3c6d1

charles-zablit requested a review from JDevlieghere as a code owner May 20, 2025 16:48

llvmbot added the lldb label May 20, 2025

remove redundant check

296a105

JDevlieghere requested a review from Michael137 May 20, 2025 23:19

Michael137 reviewed May 21, 2025

View reviewed changes

charles-zablit added 2 commits May 27, 2025 14:40

update documentation

32c5095

revert unnecessary changes

69e86fd

Michael137 reviewed May 27, 2025

View reviewed changes

charles-zablit added 3 commits May 27, 2025 18:25

revert changes to MangledTest.cpp

ce31f3a

fixup! revert changes to MangledTest.cpp

68e3fd7

add test to show that function.prefix is a no-op

0acb2a4

charles-zablit mentioned this pull request May 27, 2025

[Syntax Highlighting] Add name and parameters syntax highlighting in Swift backtraces swiftlang/llvm-project#10710

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Michael137 reviewed May 28, 2025

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lldb/source/Core/Mangled.cpp Outdated Show resolved Hide resolved

Michael137 approved these changes May 28, 2025

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Michael137 reviewed May 28, 2025

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charles-zablit and others added 2 commits May 28, 2025 11:27

Update lldb/source/Core/Mangled.cpp

c74d879

Co-authored-by: Michael Buch <michaelbuch12@gmail.com>

Update lldb/docs/use/formatting.rst

85416f9

Co-authored-by: Michael Buch <michaelbuch12@gmail.com>

Michael137 merged commit b8997c0 into llvm:main May 28, 2025
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charles-zablit mentioned this pull request May 28, 2025

add explicit default initialization to DemangledNameInfo to remove warning #141790

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charles-zablit mentioned this pull request May 30, 2025

🍒 [LLDB] Refactor demangler range tracking swiftlang/llvm-project#10767

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charles-zablit mentioned this pull request Jun 20, 2025

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