CMake error : multiple definitions and undefined references

[gusix]

It doesn't seem to build on arch, maybe its on my side but either from the AUR or straight from git I get the same error trying to build on linux

/usr/bin/ld: CMakeFiles/roxml-dynamic.dir/src/roxml_mem.c.o:(.data+0x0): multiple definition of `head_cell'; CMakeFiles/roxml-dynamic.dir/src/roxml_content.c.o:(.bss+0x0): first defined here

[emmanuel-deloget]

This is not an "undefined symbol" error, it's a multiple definition error.

Reading the code, I cannot find anything wrong wrt head_cell. roxml_content.c in particular does not define head_cell ; it doesn't even use the declaration of head_cell in roxml_mem.h.

What compiler (name, version) did you use? could you send a compilation log ?

[gusix]

From a fresh repo, I had other errors but the same kind, using GCC 12.1.1 on Arch.

https://pastebin.com/raw/p59xY6hR

[emmanuel-deloget]

Hello,

Got it. _nb_node is defined in roxml-core.h as

unsigned int _nb_node;

Wich means that each compulation unit that include this file will get its own public copy of _nb_node. The same goes for _nb_attr and _nb_text. They are defined only when DEBUG is defined, which happens to be true when compiling the unit tests.

Marking the variables as extern solve this (see PR #83). Once solved, we get a few undefined symbol - but only when building with cmake. The autoconf-powered build does not have this problem so it's clearly a buil-related issue that I will investigate later.

Please note that you can avoid the build of the unit test using cmake by using -D BUILD_TESTING=0 on the cmake command line.

[blunderer]

That leaves us with the remaining undefined references on cmake.

[blunderer]

I believe the issue comes from cmake not recompiling the roxml sources with -D__DEBUG defined resulting in the functions being declared as static and not visible.

The autotools version rebuilds the sources specially for the unittest binary, and the -D__DEBUG flag disables the "static".

[baemhai]

Faced the same problem, added another extern in /src/roxml_internal.h to satisfy clang

#ifdef __DEBUG
#define ROXML_STATIC extern
#else
#define ROXML_STATIC static
#endif