UnDecorateSymbolName function (dbghelp.h)

Article
08/09/2022

Undecorates the specified decorated C++ symbol name.

Syntax

DWORD IMAGEAPI UnDecorateSymbolName(
  [in]  PCSTR name,
  [out] PSTR  outputString,
  [in]  DWORD maxStringLength,
  [in]  DWORD flags
);

Parameters

[in] name

The decorated C++ symbol name. This name can be identified by the first character of the name, which is always a question mark (?).

[out] outputString

A pointer to a string buffer that receives the undecorated name.

[in] maxStringLength

The size of the UnDecoratedName buffer, in characters.

[in] flags

The options for how the decorated name is undecorated. This parameter can be zero or more of the following values.

Value	Meaning
UNDNAME_32_BIT_DECODE 0x0800	Undecorate 32-bit decorated names.
UNDNAME_COMPLETE 0x0000	Enable full undecoration.
UNDNAME_NAME_ONLY 0x1000	Undecorate only the name for primary declaration. Returns [scope::]name. Does expand template parameters.
UNDNAME_NO_ACCESS_SPECIFIERS 0x0080	Disable expansion of access specifiers for members.
UNDNAME_NO_ALLOCATION_LANGUAGE 0x0010	Disable expansion of the declaration language specifier.
UNDNAME_NO_ALLOCATION_MODEL 0x0008	Disable expansion of the declaration model.
UNDNAME_NO_ARGUMENTS 0x2000	Do not undecorate function arguments.
UNDNAME_NO_CV_THISTYPE 0x0040	Disable expansion of CodeView modifiers on the this type for primary declaration.
UNDNAME_NO_FUNCTION_RETURNS 0x0004	Disable expansion of return types for primary declarations.
UNDNAME_NO_LEADING_UNDERSCORES 0x0001	Remove leading underscores from Microsoft keywords.
UNDNAME_NO_MEMBER_TYPE 0x0200	Disable expansion of the static or virtual attribute of members.
UNDNAME_NO_MS_KEYWORDS 0x0002	Disable expansion of Microsoft keywords.
UNDNAME_NO_MS_THISTYPE 0x0020	Disable expansion of Microsoft keywords on the this type for primary declaration.
UNDNAME_NO_RETURN_UDT_MODEL 0x0400	Disable expansion of the Microsoft model for user-defined type returns.
UNDNAME_NO_SPECIAL_SYMS 0x4000	Do not undecorate special names, such as vtable, vcall, vector, metatype, and so on.
UNDNAME_NO_THISTYPE 0x0060	Disable all modifiers on the this type.
UNDNAME_NO_THROW_SIGNATURES 0x0100	Disable expansion of throw-signatures for functions and pointers to functions.

Return value

If the function succeeds, the return value is the number of characters in the UnDecoratedName buffer, not including the NULL terminator.

If the function fails, the return value is zero. To retrieve extended error information, call GetLastError.

If the function fails and returns zero, the content of the UnDecoratedName buffer is undetermined.

Remarks

To use undecorated symbols, call the SymSetOptions function with the SYMOPT_UNDNAME option.

All DbgHelp functions, such as this one, are single threaded. Therefore, calls from more than one thread to this function will likely result in unexpected behavior or memory corruption. To avoid this, you must synchronize all concurrent calls from more than one thread to this function.

To call the Unicode version of this function, define DBGHELP_TRANSLATE_TCHAR.

Examples

For an example, see Retrieving Undecorated Symbol Names.

Requirements

Requirement	Value
Target Platform	Windows
Header	dbghelp.h
Library	Dbghelp.lib
DLL	Dbghelp.dll
Redistributable	DbgHelp.dll 5.1 or later