Bug: Extension error on double definition

[arwedus]

When running sphinx-build (5.3) with sphinxcontrib.doxylink (1.12.2) added on a doxygen XML generated with doxygen 1.9.7, I get the following errors in the build.

Example 1: the same local definition, but different

Extension error (sphinxcontrib.doxylink.doxylink):
Handler <function setup_doxylink_roles at 0x7f57602343a0> for event 'builder-inited' threw an exception (exception: Cannot add override to non-function 'msr::g_stopWatch')

I can't post the full example because the project is huge (and proprietary), so maybe could you give a few hints for which things to look out first?

The symbol that sphinx complains about is a global variable in two files:

// file: msr_rsp_runnable.cpp
namespace msr
{
extern msr::CStopWatch g_stopWatch;
}

second cpp file:

// file: msr_sfm_runnable.cpp
namespace msr
{
msr::CStopWatch g_stopWatch(12000);
} // namespace msr

The doxygen.tag file contains the symbol 4 times:

  <compound kind="file">
    <name>msr_rsp_runnable.cpp</name>
    <path>msr/msr_rsp/src/</path>
    <filename>msr__rsp__runnable_8cpp.html</filename>
    <namespace>msr</namespace>
    <member kind="variable">
      <type>msr::CStopWatch</type>
      <name>g_stopWatch</name>
      <anchorfile>namespacemsr.html</anchorfile>
      <anchor>a8dd8d700e0974fec9a7f7e38c55d1642</anchor>
      <arglist></arglist>
    </member>
  </compound>
  <compound kind="file">
    <name>msr_sfm_runnable.cpp</name>
    <path>msr/msr_sfm/src/</path>
    <filename>msr__sfm__runnable_8cpp.html</filename>
    <namespace>msr</namespace>
    <member kind="function">
      <type>msr::CStopWatch</type>
      <name>g_stopWatch</name>
      <anchorfile>namespacemsr.html</anchorfile>
      <anchor>af171e57ba75ecc541531fc57d7452bc5</anchor>
      <arglist>(12000)</arglist>
    </member>
  <compound kind="namespace">
    <name>msr</name>
    <filename>namespacemsr.html</filename>
    <member kind="function">
      <type>msr::CStopWatch</type>
      <name>g_stopWatch</name>
      <anchorfile>namespacemsr.html</anchorfile>
      <anchor>af171e57ba75ecc541531fc57d7452bc5</anchor>
      <arglist>(12000)</arglist>
    </member>
    <member kind="variable">
      <type>msr::CStopWatch</type>
      <name>g_stopWatch</name>
      <anchorfile>namespacemsr.html</anchorfile>
      <anchor>a8dd8d700e0974fec9a7f7e38c55d1642</anchor>
      <arglist></arglist>
    </member>
    <!-- ... -->
  </compound>

I think it is a problem of doxygen that it adds the variable with initalizer value as a function. Anyhow, would it be possible to catch this gently?

Example 2: Overriding #define

The same problem occurs in other kinds of "double definition by doxygen" situations, like:

// NEON_2_SSE.h
_NEON2SSESTORAGE uint8x8_t vadd_u8(uint8x8_t a, uint8x8_t b); // VADD.I8 d0,d0,d0
#define vadd_u8 vadd_s8

Doxygen XML:

  <compound kind="file">
    <name>NEON_2_SSE.h</name>
    <member kind="define">
      <type>#define</type>
      <name>vadd_u8</name>
      <anchorfile>NEON__2__SSE_8h.html</anchorfile>
      <anchor>a8744a9ca1aa66ab5e9cf9bc706a318c1</anchor>
      <arglist></arglist>
    </member>
    <member kind="function" static="yes">
      <type>static uint8x8_t</type>
      <name>vadd_u8</name>
      <anchorfile>NEON__2__SSE_8h.html</anchorfile>
      <anchor>a13f1019c21aa0d41088901b549d40570</anchor>
      <arglist>(uint8x8_t a, uint8x8_t b)</arglist>
    </member>

Doxylink error:

Extension error (sphinxcontrib.doxylink.doxylink):
Handler <function setup_doxylink_roles at 0x7f7b9b5ba3a0> for event 'builder-inited' threw an exception (exception: Cannot add override to non-function 'cfc_NEON_2_SSE.hpp::vadd_u8')

None of that code is nice, but I'd argue that this code exists and C/C++ builds it, so it should not lead to a crash of sphinxcontrib.doxylink.

Example 3: SFINAE

Here, I have totally valid C++ SFINAE template code that causes the dreaded error again:

Extension error (sphinxcontrib.doxylink.doxylink):
Handler <function setup_doxylink_roles at 0x7f22564e33a0> for event 'builder-inited' threw an exception (exception: Cannot add override to non-function 'loft2_int::exporter::has_method::test')

The C++ code (header file):

#include <type_traits>

namespace loft2_int
{
namespace exporter
{

// The template has_method<T> exports a boolean constant
// value that is true iff T provides int T::getDetectionID() const
template <typename ObjectType>
struct has_method
{
    // SFINAE: ensure correct signature via function pointer
    template <typename InternalObjectType>
    static std::true_type test(int (InternalObjectType::*)() const)
    {
        return std::true_type();
    }

    // SFINAE: ensure that method exists
    template <typename InternalObjectType>
    static decltype(test(&InternalObjectType::getDetectionID))
    test(decltype(&InternalObjectType::getDetectionID), void*)
    {
        // method exists, now check for correct signature
        using Return_type = decltype(test(&InternalObjectType::getDetectionID));
        return Return_type();
    }

    // SFINAE: otherwise return false type
    template <typename InternalObjectType>
    static std::false_type test(...)
    {
        return std::false_type();
    }

    // This will be either std::true_type or std::false_type
    using ResultType = decltype(test<ObjectType>(nullptr, nullptr));

    // make value accessible from outside
    static constexpr bool value = ResultType::value;
};

Doxygen gets the last one wrong:

  <compound kind="struct">
    <name>loft2_int::exporter::has_method</name>
    <filename>structloft2__int_1_1exporter_1_1has__method.html</filename>
    <templarg>typename ObjectType</templarg>
    <!-- ... -->
    <member kind="function" static="yes">
      <type>static std::true_type</type>
      <name>test</name>
      <anchorfile>structloft2__int_1_1exporter_1_1has__method.html</anchorfile>
      <anchor>aa271aedf2af8565e5c7fb5190032809e</anchor>
      <arglist>(int(InternalObjectType::*)() const)</arglist>
    </member>
    <member kind="function" static="yes">
      <type>static std::false_type</type>
      <name>test</name>
      <anchorfile>structloft2__int_1_1exporter_1_1has__method.html</anchorfile>
      <anchor>a604f0c99be193a6e7d9d455174c528c4</anchor>
      <arglist>(...)</arglist>
    </member>
    <member kind="variable" static="yes">
      <type>static decltype(test(&amp;InternalObjectType::getDetectionID))</type>
      <name>test</name>
      <anchorfile>structloft2__int_1_1exporter_1_1has__method.html</anchorfile>
      <anchor>a4553d86d6a8ba6c1045e0e65a34ff915</anchor>
      <arglist>(decltype(&amp;InternalObjectType::getDetectionID), void *)</arglist>
    </member>