Warnings when documenting members of classes in unnamed namespaces (Origin: bugzilla #412978)

[doxygen]

status NEW severity normal in component general for --- Reported in version 1.5.3-SVN on platform Other Assigned to: Dimitri van Heesch

On 2007-02-28 07:46:59 +0000, Braden wrote:

Please describe the problem:
Using doxygen 1.5.1-20070219, I'm getting warnings that look like this:

/home/braden/src/openvrml/openvrml-0.16/src/libopenvrml/openvrml/vrml97node.cpp:12276:
    Warning: no uniquely matching class member found for
      font_style_node::font_style_metatype
    Possible candidates:
      friend class @29::font_style_node::font_style_metatype at line 3056 of
    file
    /home/braden/src/openvrml/openvrml-0.16/src/libopenvrml/openvrml/vrml97node.cpp
/home/braden/src/openvrml/openvrml-0.16/src/libopenvrml/openvrml/vrml97node.cpp:12282:
    Warning: no matching class member found for
      openvrml::mfstring font_style_node::family_
    Possible candidates:
      mfstring @29::font_style_node::family_

Corresponding doc-comments:

    /**
     * @var font_style_node::font_style_metatype
     *
     * @brief Class object for FontStyle nodes.
     */

    /**
     * @var openvrml::mfstring font_style_node::family_
     *
     * @brief family field.
     */

font_style_metatype is a friend class; family_ is a member variable. This
seems to be happening for all @var documentation where the class is in an
unnamed namespace.

Steps to reproduce:

Actual results:

Expected results:

Does this happen every time?

Other information:

[AlexisWilke]

I (and I'm sure many others) have run in the same problem.

I get the same error:

Searching for member function documentation... /tmp/sample.cpp:73: warning: no uniquely matching class member found for void anonymous_namespace sample A::anonymous_namespace{sample.cpp}::A::cpp::D::init()

From the following sample.cpp file:

/** \file
 * \brief Sample to test the problem with a no-name namespace.
 *
 * There seems to be a problem with name spaces that are unamed
 * and overloaded functions.
 */

/** \brief Named namespaces seem okay.
 *
 * When you give the namespace a valid name, it looks like it works as
 * expected.
 */
namespace A
{

/** \brief Base class
 *
 * This is the base class.
 */
class B
{
public:
    virtual void    init();
};

/** \brief Base class init info.
 *
 * This is the init() function in the base class.
 */
void B::init()
{
}

} // A namespace

// usually in another file
namespace A
{

/** \brief Make sure the derived class is anonymous.
 *
 * In C++ we use unnamed namespaces instead of "static" like in C.
 * This is in part because "static" doesn't work against classes
 * and many other declarations. It pretty much only works for
 * variables and functions. In C++ that can be a problem, though.
 */
namespace
{

/** \brief Derived class.
 *
 * We derive D from the base class B.
 */
class D : public B
{
public:
    virtual void    init();
};

/** \brief Derived class init info.
 *
 * This should show up in the D class init function documentation.
 */
void D::init()
{
}

} // no name namespace

} // A namespace

And a pretty standard sample.doxy file as follow:

DOXYFILE_ENCODING      = UTF-8
PROJECT_NAME           = "sample"
PROJECT_NUMBER         = 1.2
PROJECT_BRIEF          = "sample showing the failing unnamed namespace"
PROJECT_LOGO           =
OUTPUT_DIRECTORY       = docs
CREATE_SUBDIRS         = NO
ALLOW_UNICODE_NAMES    = NO
OUTPUT_LANGUAGE        = English
BRIEF_MEMBER_DESC      = YES
REPEAT_BRIEF           = NO
ABBREVIATE_BRIEF       =
ALWAYS_DETAILED_SEC    = NO
INLINE_INHERITED_MEMB  = YES
FULL_PATH_NAMES        = YES
STRIP_FROM_PATH        =
STRIP_FROM_INC_PATH    =
SHORT_NAMES            = NO
JAVADOC_AUTOBRIEF      = NO
QT_AUTOBRIEF           = NO
MULTILINE_CPP_IS_BRIEF = NO
INHERIT_DOCS           = YES
SEPARATE_MEMBER_PAGES  = NO
TAB_SIZE               = 4
ALIASES                = "TODO=@todo" \
                         "FIXME=@todo" \
                         "TBD=@todo"
TCL_SUBST              =
OPTIMIZE_OUTPUT_FOR_C  = NO
OPTIMIZE_OUTPUT_JAVA   = NO
OPTIMIZE_FOR_FORTRAN   = NO
OPTIMIZE_OUTPUT_VHDL   = NO
EXTENSION_MAPPING      =
MARKDOWN_SUPPORT       = YES
AUTOLINK_SUPPORT       = YES
BUILTIN_STL_SUPPORT    = NO
CPP_CLI_SUPPORT        = NO
SIP_SUPPORT            = NO
IDL_PROPERTY_SUPPORT   = YES
DISTRIBUTE_GROUP_DOC   = NO
GROUP_NESTED_COMPOUNDS = NO
SUBGROUPING            = YES
INLINE_GROUPED_CLASSES = NO
INLINE_SIMPLE_STRUCTS  = NO
TYPEDEF_HIDES_STRUCT   = NO
LOOKUP_CACHE_SIZE      = 0
EXTRACT_ALL            = YES
EXTRACT_PRIVATE        = YES
EXTRACT_PACKAGE        = NO
EXTRACT_STATIC         = YES
EXTRACT_LOCAL_CLASSES  = YES
EXTRACT_LOCAL_METHODS  = NO
EXTRACT_ANON_NSPACES   = YES
HIDE_UNDOC_MEMBERS     = NO
HIDE_UNDOC_CLASSES     = NO
HIDE_FRIEND_COMPOUNDS  = NO
HIDE_IN_BODY_DOCS      = NO
INTERNAL_DOCS          = YES
CASE_SENSE_NAMES       = YES
HIDE_SCOPE_NAMES       = NO
HIDE_COMPOUND_REFERENCE= NO
SHOW_INCLUDE_FILES     = YES
SHOW_GROUPED_MEMB_INC  = NO
FORCE_LOCAL_INCLUDES   = NO
INLINE_INFO            = YES
SORT_MEMBER_DOCS       = YES
SORT_BRIEF_DOCS        = YES
SORT_MEMBERS_CTORS_1ST = YES
SORT_GROUP_NAMES       = NO
SORT_BY_SCOPE_NAME     = NO
STRICT_PROTO_MATCHING  = NO
GENERATE_TODOLIST      = YES
GENERATE_TESTLIST      = YES
GENERATE_BUGLIST       = YES
GENERATE_DEPRECATEDLIST= YES
ENABLED_SECTIONS       =
MAX_INITIALIZER_LINES  = 30
SHOW_USED_FILES        = YES
SHOW_FILES             = YES
SHOW_NAMESPACES        = YES
FILE_VERSION_FILTER    =
LAYOUT_FILE            =
CITE_BIB_FILES         =
QUIET                  = NO
WARNINGS               = YES
WARN_IF_UNDOCUMENTED   = YES
WARN_IF_DOC_ERROR      = YES
WARN_NO_PARAMDOC       = YES
WARN_AS_ERROR          = NO
WARN_FORMAT            = "$file:$line: $text"
WARN_LOGFILE           =
INPUT                  = .
INPUT_ENCODING         = UTF-8
FILE_PATTERNS          = *.h \
                         *.h.in \
                         *.hpp \
                         *.hpp.in \
                         *.cpp \
                         *.c
RECURSIVE              = YES
EXCLUDE                =
EXCLUDE_SYMLINKS       = NO
EXCLUDE_PATTERNS       =
EXCLUDE_SYMBOLS        =
EXAMPLE_PATH           = .
EXAMPLE_PATTERNS       = *example*.cpp
EXAMPLE_RECURSIVE      = NO
IMAGE_PATH             =
INPUT_FILTER           =
FILTER_PATTERNS        =
FILTER_SOURCE_FILES    = NO
FILTER_SOURCE_PATTERNS =
USE_MDFILE_AS_MAINPAGE =
SOURCE_BROWSER         = YES
INLINE_SOURCES         = NO
STRIP_CODE_COMMENTS    = YES
REFERENCED_BY_RELATION = YES
REFERENCES_RELATION    = YES
REFERENCES_LINK_SOURCE = YES
SOURCE_TOOLTIPS        = YES
USE_HTAGS              = NO
VERBATIM_HEADERS       = YES
CLANG_ASSISTED_PARSING = NO
CLANG_OPTIONS          =
ALPHABETICAL_INDEX     = YES
COLS_IN_ALPHA_INDEX    = 5
IGNORE_PREFIX          = m_
GENERATE_HTML          = YES
HTML_OUTPUT            = html
HTML_FILE_EXTENSION    = .html
HTML_HEADER            =
HTML_FOOTER            =
HTML_STYLESHEET        =
HTML_EXTRA_STYLESHEET  =
HTML_EXTRA_FILES       =
HTML_COLORSTYLE_HUE    = 220
HTML_COLORSTYLE_SAT    = 100
HTML_COLORSTYLE_GAMMA  = 80
HTML_TIMESTAMP         = YES
HTML_DYNAMIC_SECTIONS  = NO
HTML_INDEX_NUM_ENTRIES = 100
GENERATE_DOCSET        = NO
DOCSET_FEEDNAME        = "Doxygen generated docs"
DOCSET_BUNDLE_ID       = org.doxygen.Project
DOCSET_PUBLISHER_ID    = org.doxygen.Publisher
DOCSET_PUBLISHER_NAME  = Publisher
GENERATE_HTMLHELP      = NO
CHM_FILE               =
HHC_LOCATION           =
GENERATE_CHI           = NO
CHM_INDEX_ENCODING     =
BINARY_TOC             = NO
TOC_EXPAND             = NO
GENERATE_QHP           = NO
QCH_FILE               =
QHP_NAMESPACE          = org.doxygen.Project
QHP_VIRTUAL_FOLDER     = doc
QHP_CUST_FILTER_NAME   =
QHP_CUST_FILTER_ATTRS  =
QHP_SECT_FILTER_ATTRS  =
QHG_LOCATION           =
GENERATE_ECLIPSEHELP   = NO
ECLIPSE_DOC_ID         = org.doxygen.Project
DISABLE_INDEX          = NO
GENERATE_TREEVIEW      = NO
ENUM_VALUES_PER_LINE   = 1
TREEVIEW_WIDTH         = 250
EXT_LINKS_IN_WINDOW    = NO
FORMULA_FONTSIZE       = 10
FORMULA_TRANSPARENT    = YES
USE_MATHJAX            = YES
MATHJAX_FORMAT         = HTML-CSS
MATHJAX_RELPATH        = http://cdn.mathjax.org/mathjax/latest
MATHJAX_EXTENSIONS     =
MATHJAX_CODEFILE       =
SEARCHENGINE           = NO
SERVER_BASED_SEARCH    = NO
EXTERNAL_SEARCH        = NO
SEARCHENGINE_URL       =
SEARCHDATA_FILE        = searchdata.xml
EXTERNAL_SEARCH_ID     =
EXTRA_SEARCH_MAPPINGS  =
GENERATE_LATEX         = YES
LATEX_OUTPUT           = latex
LATEX_CMD_NAME         = latex
MAKEINDEX_CMD_NAME     = makeindex
COMPACT_LATEX          = NO
PAPER_TYPE             = a4
EXTRA_PACKAGES         =
LATEX_HEADER           =
LATEX_FOOTER           =
LATEX_EXTRA_STYLESHEET =
LATEX_EXTRA_FILES      =
PDF_HYPERLINKS         = YES
USE_PDFLATEX           = YES
LATEX_BATCHMODE        = NO
LATEX_HIDE_INDICES     = NO
LATEX_SOURCE_CODE      = NO
LATEX_BIB_STYLE        = plain
LATEX_TIMESTAMP        = NO
GENERATE_RTF           = NO
RTF_OUTPUT             = rtf
COMPACT_RTF            = NO
RTF_HYPERLINKS         = NO
RTF_STYLESHEET_FILE    =
RTF_EXTENSIONS_FILE    =
RTF_SOURCE_CODE        = NO
GENERATE_MAN           = YES
MAN_OUTPUT             = man
MAN_EXTENSION          = .3
MAN_SUBDIR             =
MAN_LINKS              = NO
GENERATE_XML           = NO
XML_OUTPUT             = xml
XML_PROGRAMLISTING     = YES
GENERATE_DOCBOOK       = NO
DOCBOOK_OUTPUT         = docbook
DOCBOOK_PROGRAMLISTING = NO
GENERATE_AUTOGEN_DEF   = NO
GENERATE_PERLMOD       = NO
PERLMOD_LATEX          = NO
PERLMOD_PRETTY         = YES
PERLMOD_MAKEVAR_PREFIX =
ENABLE_PREPROCESSING   = YES
MACRO_EXPANSION        = NO
EXPAND_ONLY_PREDEF     = NO
SEARCH_INCLUDES        = YES
INCLUDE_PATH           =
INCLUDE_FILE_PATTERNS  =
PREDEFINED             =
EXPAND_AS_DEFINED      =
SKIP_FUNCTION_MACROS   = YES
TAGFILES               =
GENERATE_TAGFILE       =
ALLEXTERNALS           = NO
EXTERNAL_GROUPS        = YES
EXTERNAL_PAGES         = YES
PERL_PATH              = /usr/bin/perl
CLASS_DIAGRAMS         = YES
MSCGEN_PATH            =
DIA_PATH               =
HIDE_UNDOC_RELATIONS   = YES
HAVE_DOT               = YES
DOT_NUM_THREADS        = 0
DOT_FONTNAME           = Helvetica
DOT_FONTSIZE           = 10
DOT_FONTPATH           =
CLASS_GRAPH            = YES
COLLABORATION_GRAPH    = YES
GROUP_GRAPHS           = YES
UML_LOOK               = NO
UML_LIMIT_NUM_FIELDS   = 10
TEMPLATE_RELATIONS     = NO
INCLUDE_GRAPH          = YES
INCLUDED_BY_GRAPH      = YES
CALL_GRAPH             = NO
CALLER_GRAPH           = NO
GRAPHICAL_HIERARCHY    = YES
DIRECTORY_GRAPH        = YES
DOT_IMAGE_FORMAT       = png
INTERACTIVE_SVG        = NO
DOT_PATH               =
DOTFILE_DIRS           =
MSCFILE_DIRS           =
DIAFILE_DIRS           =
PLANTUML_JAR_PATH      =
PLANTUML_INCLUDE_PATH  =
DOT_GRAPH_MAX_NODES    = 150
MAX_DOT_GRAPH_DEPTH    = 0
DOT_TRANSPARENT        = NO
DOT_MULTI_TARGETS      = YES
GENERATE_LEGEND        = YES
DOT_CLEANUP            = YES

I ran the command line:

doxygen sample.doxy

and get the error message mentioned above. Also, the documentation of the D::init() function is completely ignored (not present in the final HTML documentation.)

From other things I've seen in Doxygen, it feels like the unnamed namespaces are given a name which is the name of the file in which they appear and the line number. It seems to me that this is unique enough to end up with a clearly distinct name for each element in such a block.

Current fix for those who do not mind is to give the namespace a name. So in my example above, I could change:

namespace
{

With:

namespace internals
{

and Doxygen is all happy and gets it right.

[AlexisWilke]

Here is another reference where someone reported a problem with an unnamed namespace.

Doxygen complains about overloaded functions that take same template but with different template parameter

For those interested I added a possible solution as an answer. It's a hack, but it seems to work, at least in my situation. It may help others similarly.

[albert-github]

@AlexisWilke The example is nice but it is preferred to have it as an attached, small, self contained example (source+configuration file in a tar or zip) that allows us to reproduce the problem? Please don't add external links as they might not be persistent. Saves a lot of cutting and pasting.

[AlexisWilke]

The sample code from above in a tarball.

sample.tar.gz

[albert-github]

With the doxygen 1.8.16 version we get the warning as indicated for the example given by @AlexisWilke . With the current doxygen version (1.9.6) this warning is gone (and as far as I can see the documentation is as intended).

Also for the original problem the indicated warnings are gone.

I think the problem has been solved in the mean time.