[lldb] Add support for displaying __float128 variables (llvm#98369)

beetrees · web-flow · commit e15b3ef704de · 2025-07-31T18:04:48.000-07:00
diff --git a/lldb/bindings/python/python-extensions.swig b/lldb/bindings/python/python-extensions.swig
@@ -594,6 +594,7 @@ def is_numeric_type(basic_type):
     if basic_type == eBasicTypeFloat: return (True,True)
     if basic_type == eBasicTypeDouble: return (True,True)
     if basic_type == eBasicTypeLongDouble: return (True,True)
+    if basic_type == eBasicTypeFloat128: return (True,True)
     if basic_type == eBasicTypeFloatComplex: return (True,True)
     if basic_type == eBasicTypeDoubleComplex: return (True,True)
     if basic_type == eBasicTypeLongDoubleComplex: return (True,True)
diff --git a/lldb/docs/python_api_enums.rst b/lldb/docs/python_api_enums.rst
@@ -321,6 +321,7 @@ Format
 .. py:data:: eFormatInstruction
 .. py:data:: eFormatVoid
 .. py:data:: eFormatUnicode8
+.. py:data:: eFormatFloat128
 
 
 .. _DescriptionLevel:
@@ -1045,6 +1046,7 @@ BasicType
 .. py:data:: eBasicTypeObjCSel
 .. py:data:: eBasicTypeNullPtr
 .. py:data:: eBasicTypeOther
+.. py:data:: eBasicTypeFloat128
 
 
 .. _TraceType:
diff --git a/lldb/include/lldb/Symbol/TypeSystem.h b/lldb/include/lldb/Symbol/TypeSystem.h
@@ -310,7 +310,8 @@ class TypeSystem : public PluginInterface,
 
   // Exploring the type
 
-  virtual const llvm::fltSemantics &GetFloatTypeSemantics(size_t byte_size) = 0;
+  virtual const llvm::fltSemantics &
+  GetFloatTypeSemantics(size_t byte_size, lldb::Format format) = 0;
 
   virtual llvm::Expected<uint64_t>
   GetBitSize(lldb::opaque_compiler_type_t type,
diff --git a/lldb/include/lldb/lldb-enumerations.h b/lldb/include/lldb/lldb-enumerations.h
@@ -198,11 +198,15 @@ enum Format {
                          ///< character arrays that can contain non printable
                          ///< characters
   eFormatAddressInfo,    ///< Describe what an address points to (func + offset
-                      ///< with file/line, symbol + offset, data, etc)
-  eFormatHexFloat,    ///< ISO C99 hex float string
-  eFormatInstruction, ///< Disassemble an opcode
-  eFormatVoid,        ///< Do not print this
+                         ///< with file/line, symbol + offset, data, etc)
+  eFormatHexFloat,       ///< ISO C99 hex float string
+  eFormatInstruction,    ///< Disassemble an opcode
+  eFormatVoid,           ///< Do not print this
   eFormatUnicode8,
+  eFormatFloat128, ///< Disambiguate between 128-bit `long double` (which uses
+                   ///< `eFormatFloat`) and `__float128` (which uses
+                   ///< `eFormatFloat128`). If the value being formatted is not
+                   ///< 128 bits, then this is identical to `eFormatFloat`.
   kNumFormats
 };
 
@@ -838,7 +842,8 @@ enum BasicType {
   eBasicTypeObjCClass,
   eBasicTypeObjCSel,
   eBasicTypeNullPtr,
-  eBasicTypeOther
+  eBasicTypeOther,
+  eBasicTypeFloat128
 };
 
 /// Deprecated
diff --git a/lldb/source/Commands/CommandObjectMemory.cpp b/lldb/source/Commands/CommandObjectMemory.cpp
@@ -156,6 +156,7 @@ class OptionGroupReadMemory : public OptionGroup {
 
     case eFormatBinary:
     case eFormatFloat:
+    case eFormatFloat128:
     case eFormatOctal:
     case eFormatDecimal:
     case eFormatEnum:
@@ -1356,6 +1357,7 @@ class CommandObjectMemoryWrite : public CommandObjectParsed {
       switch (m_format_options.GetFormat()) {
       case kNumFormats:
       case eFormatFloat: // TODO: add support for floats soon
+      case eFormatFloat128:
       case eFormatCharPrintable:
       case eFormatBytesWithASCII:
       case eFormatComplex:
diff --git a/lldb/source/Core/DumpDataExtractor.cpp b/lldb/source/Core/DumpDataExtractor.cpp
@@ -318,14 +318,15 @@ static void printMemoryTags(const DataExtractor &DE, Stream *s,
 }
 
 static const llvm::fltSemantics &GetFloatSemantics(const TargetSP &target_sp,
-                                                   size_t byte_size) {
+                                                   size_t byte_size,
+                                                   lldb::Format format) {
   if (target_sp) {
     auto type_system_or_err =
       target_sp->GetScratchTypeSystemForLanguage(eLanguageTypeC);
     if (!type_system_or_err)
       llvm::consumeError(type_system_or_err.takeError());
     else if (auto ts = *type_system_or_err)
-      return ts->GetFloatTypeSemantics(byte_size);
+      return ts->GetFloatTypeSemantics(byte_size, format);
   }
   // No target, just make a reasonable guess
   switch(byte_size) {
@@ -335,7 +336,13 @@ static const llvm::fltSemantics &GetFloatSemantics(const TargetSP &target_sp,
       return llvm::APFloat::IEEEsingle();
     case 8:
       return llvm::APFloat::IEEEdouble();
-  }
+    case 16:
+      if (format == eFormatFloat128) {
+        return llvm::APFloat::IEEEquad();
+      }
+      // Otherwise it's ambigious whether a 16-byte float is a float128 or a
+      // target-specific long double.
+    }
   return llvm::APFloat::Bogus();
 }
 
@@ -653,6 +660,7 @@ lldb::offset_t lldb_private::DumpDataExtractor(
       }
     } break;
 
+    case eFormatFloat128:
     case eFormatFloat: {
       TargetSP target_sp;
       if (exe_scope)
@@ -666,7 +674,7 @@ lldb::offset_t lldb_private::DumpDataExtractor(
       const unsigned format_precision = 0;
 
       const llvm::fltSemantics &semantics =
-          GetFloatSemantics(target_sp, item_byte_size);
+          GetFloatSemantics(target_sp, item_byte_size, item_format);
 
       // Recalculate the byte size in case of a difference. This is possible
       // when item_byte_size is 16 (128-bit), because you could get back the
diff --git a/lldb/source/DataFormatters/FormatManager.cpp b/lldb/source/DataFormatters/FormatManager.cpp
@@ -72,6 +72,7 @@ static constexpr FormatInfo g_format_infos[] = {
     {eFormatInstruction, 'i', "instruction"},
     {eFormatVoid, 'v', "void"},
     {eFormatUnicode8, 'u', "unicode8"},
+    {eFormatFloat128, '\0', "float128"},
 };
 
 static_assert((sizeof(g_format_infos) / sizeof(g_format_infos[0])) ==
diff --git a/lldb/source/DataFormatters/VectorType.cpp b/lldb/source/DataFormatters/VectorType.cpp
@@ -55,6 +55,8 @@ static CompilerType GetCompilerTypeForFormat(lldb::Format format,
 
   case lldb::eFormatFloat:
     return type_system->GetBasicTypeFromAST(lldb::eBasicTypeFloat);
+  case lldb::eFormatFloat128:
+    return type_system->GetBasicTypeFromAST(lldb::eBasicTypeFloat128);
 
   case lldb::eFormatHex:
   case lldb::eFormatHexUppercase:
diff --git a/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp b/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp
@@ -795,6 +795,8 @@ TypeSystemClang::GetBuiltinTypeForEncodingAndBitSize(Encoding encoding,
       return GetType(ast.LongDoubleTy);
     if (QualTypeMatchesBitSize(bit_size, ast, ast.HalfTy))
       return GetType(ast.HalfTy);
+    if (QualTypeMatchesBitSize(bit_size, ast, ast.Float128Ty))
+      return GetType(ast.Float128Ty);
     break;
 
   case eEncodingVector:
@@ -956,6 +958,13 @@ CompilerType TypeSystemClang::GetBuiltinTypeForDWARFEncodingAndBitSize(
     if (type_name == "long double" &&
         QualTypeMatchesBitSize(bit_size, ast, ast.LongDoubleTy))
       return GetType(ast.LongDoubleTy);
+    // As Rust currently uses `TypeSystemClang`, match `f128` here as well so it
+    // doesn't get misinterpreted as `long double` on targets where they are
+    // the same size but different formats.
+    if ((type_name == "__float128" || type_name == "_Float128" ||
+         type_name == "f128") &&
+        QualTypeMatchesBitSize(bit_size, ast, ast.Float128Ty))
+      return GetType(ast.Float128Ty);
     // Fall back to not requiring a name match
     if (QualTypeMatchesBitSize(bit_size, ast, ast.FloatTy))
       return GetType(ast.FloatTy);
@@ -965,6 +974,8 @@ CompilerType TypeSystemClang::GetBuiltinTypeForDWARFEncodingAndBitSize(
       return GetType(ast.LongDoubleTy);
     if (QualTypeMatchesBitSize(bit_size, ast, ast.HalfTy))
       return GetType(ast.HalfTy);
+    if (QualTypeMatchesBitSize(bit_size, ast, ast.Float128Ty))
+      return GetType(ast.Float128Ty);
     break;
 
   case DW_ATE_signed:
@@ -2054,6 +2065,8 @@ TypeSystemClang::GetOpaqueCompilerType(clang::ASTContext *ast,
     return ast->DoubleTy.getAsOpaquePtr();
   case eBasicTypeLongDouble:
     return ast->LongDoubleTy.getAsOpaquePtr();
+  case eBasicTypeFloat128:
+    return ast->Float128Ty.getAsOpaquePtr();
   case eBasicTypeFloatComplex:
     return ast->getComplexType(ast->FloatTy).getAsOpaquePtr();
   case eBasicTypeDoubleComplex:
@@ -4742,19 +4755,24 @@ CompilerType TypeSystemClang::CreateGenericFunctionPrototype() {
 // Exploring the type
 
 const llvm::fltSemantics &
-TypeSystemClang::GetFloatTypeSemantics(size_t byte_size) {
+TypeSystemClang::GetFloatTypeSemantics(size_t byte_size, lldb::Format format) {
   clang::ASTContext &ast = getASTContext();
   const size_t bit_size = byte_size * 8;
   if (bit_size == ast.getTypeSize(ast.FloatTy))
     return ast.getFloatTypeSemantics(ast.FloatTy);
   else if (bit_size == ast.getTypeSize(ast.DoubleTy))
     return ast.getFloatTypeSemantics(ast.DoubleTy);
+  else if (format == eFormatFloat128 &&
+           bit_size == ast.getTypeSize(ast.Float128Ty))
+    return ast.getFloatTypeSemantics(ast.Float128Ty);
   else if (bit_size == ast.getTypeSize(ast.LongDoubleTy) ||
            bit_size == llvm::APFloat::semanticsSizeInBits(
                            ast.getFloatTypeSemantics(ast.LongDoubleTy)))
     return ast.getFloatTypeSemantics(ast.LongDoubleTy);
   else if (bit_size == ast.getTypeSize(ast.HalfTy))
     return ast.getFloatTypeSemantics(ast.HalfTy);
+  else if (bit_size == ast.getTypeSize(ast.Float128Ty))
+    return ast.getFloatTypeSemantics(ast.Float128Ty);
   return llvm::APFloatBase::Bogus();
 }
 
@@ -5232,6 +5250,8 @@ lldb::Format TypeSystemClang::GetFormat(lldb::opaque_compiler_type_t type) {
     case clang::BuiltinType::Double:
     case clang::BuiltinType::LongDouble:
       return lldb::eFormatFloat;
+    case clang::BuiltinType::Float128:
+      return lldb::eFormatFloat128;
     default:
       return lldb::eFormatHex;
     }
@@ -5529,6 +5549,8 @@ TypeSystemClang::GetBasicTypeEnumeration(lldb::opaque_compiler_type_t type) {
         return eBasicTypeDouble;
       case clang::BuiltinType::LongDouble:
         return eBasicTypeLongDouble;
+      case clang::BuiltinType::Float128:
+        return eBasicTypeFloat128;
 
       case clang::BuiltinType::NullPtr:
         return eBasicTypeNullPtr;
@@ -6090,6 +6112,7 @@ uint32_t TypeSystemClang::GetNumPointeeChildren(clang::QualType type) {
     case clang::BuiltinType::Float:
     case clang::BuiltinType::Double:
     case clang::BuiltinType::LongDouble:
+    case clang::BuiltinType::Float128:
     case clang::BuiltinType::Dependent:
     case clang::BuiltinType::Overload:
     case clang::BuiltinType::ObjCId:
@@ -8733,6 +8756,7 @@ bool TypeSystemClang::DumpTypeValue(
         case eFormatHex:
         case eFormatHexUppercase:
         case eFormatFloat:
+        case eFormatFloat128:
         case eFormatOctal:
         case eFormatOSType:
         case eFormatUnsigned:
diff --git a/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.h b/lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.h
@@ -823,7 +823,8 @@ class TypeSystemClang : public TypeSystem {
 
   // Exploring the type
 
-  const llvm::fltSemantics &GetFloatTypeSemantics(size_t byte_size) override;
+  const llvm::fltSemantics &GetFloatTypeSemantics(size_t byte_size,
+                                                  lldb::Format format) override;
 
   llvm::Expected<uint64_t> GetByteSize(lldb::opaque_compiler_type_t type,
                                        ExecutionContextScope *exe_scope) {
diff --git a/lldb/source/ValueObject/ValueObject.cpp b/lldb/source/ValueObject/ValueObject.cpp
@@ -1466,8 +1466,9 @@ bool ValueObject::DumpPrintableRepresentation(
           (custom_format == eFormatComplexFloat) ||
           (custom_format == eFormatDecimal) || (custom_format == eFormatHex) ||
           (custom_format == eFormatHexUppercase) ||
-          (custom_format == eFormatFloat) || (custom_format == eFormatOctal) ||
-          (custom_format == eFormatOSType) ||
+          (custom_format == eFormatFloat) ||
+          (custom_format == eFormatFloat128) ||
+          (custom_format == eFormatOctal) || (custom_format == eFormatOSType) ||
           (custom_format == eFormatUnicode16) ||
           (custom_format == eFormatUnicode32) ||
           (custom_format == eFormatUnsigned) ||
diff --git a/lldb/unittests/Core/DumpDataExtractorTest.cpp b/lldb/unittests/Core/DumpDataExtractorTest.cpp
@@ -163,6 +163,9 @@ TEST_F(DumpDataExtractorTest, Formats) {
   TestDump(0xcafef00d, lldb::Format::eFormatHex, "0xcafef00d");
   TestDump(0xcafef00d, lldb::Format::eFormatHexUppercase, "0xCAFEF00D");
   TestDump(0.456, lldb::Format::eFormatFloat, "0.45600000000000002");
+  TestDump(std::vector<uint64_t>{0x47ae147ae147ae14, 0x40011147ae147ae1},
+           lldb::Format::eFormatFloat128,
+           "4.26999999999999999999999999999999963");
   TestDump(9, lldb::Format::eFormatOctal, "011");
   // Chars packed into an integer.
   TestDump<uint32_t>(0x4C4C4442, lldb::Format::eFormatOSType, "'LLDB'");
@@ -388,6 +391,9 @@ TEST_F(DumpDataExtractorTest, ItemByteSizeErrors) {
   TestDumpWithItemByteSize(
       18, lldb::Format::eFormatFloat,
       "error: unsupported byte size (18) for float format");
+  TestDumpWithItemByteSize(
+      17, lldb::Format::eFormatFloat128,
+      "error: unsupported byte size (17) for float format");
 
   // We want sizes to exactly match one of float/double.
   TestDumpWithItemByteSize(
diff --git a/lldb/unittests/Symbol/TestTypeSystemClang.cpp b/lldb/unittests/Symbol/TestTypeSystemClang.cpp
@@ -76,6 +76,8 @@ TEST_F(TestTypeSystemClang, TestGetBasicTypeFromEnum) {
                                   context.getComplexType(context.FloatTy)));
   EXPECT_TRUE(
       context.hasSameType(GetBasicQualType(eBasicTypeHalf), context.HalfTy));
+  EXPECT_TRUE(context.hasSameType(GetBasicQualType(eBasicTypeFloat128),
+                                  context.Float128Ty));
   EXPECT_TRUE(
       context.hasSameType(GetBasicQualType(eBasicTypeInt), context.IntTy));
   EXPECT_TRUE(context.hasSameType(GetBasicQualType(eBasicTypeInt128),
