Bogus indexer syntax error when using strchr

[VK2BEA]

I'm using strchr() and the eclipse C/C++ indexer shows a syntax error warning.
I'm using the gtk4 library that includes glib-2.0 on Linux.

The declaration of strchr() is in <string.h>

extern char *strchr (const char *__s, int __c)
     __THROW __attribute_pure__ __nonnull ((1));
# if __GLIBC_USE (ISOC23) && defined __glibc_const_generic && !defined _LIBC
#  define strchr(S, C)						\
  __glibc_const_generic (S, const char *, strchr (S, C))
# endif

If, in my code, I add
#undef strchr
before using strchr I get no warning and the code compiles also without error or warning.

Why is the indexer having problems with this code and is there a way to disable the warning just for this function?

Michael

[gvl2023]

In short CDT indexer is finicky but it's possible your C++ project isn't setup right. Is your project setup with CDT managed build or something else?

[VK2BEA]

Yes, managed CDT project (C not C++).
The indexer is working fine with everything else, it's just this that is giving me grief.
Since the CDT indexer and the native gcc compiler are separate (I presume), I can see that there might be the occasional issue.
It would be nice if I could just silence the known bogus errors one by one. (sort of like how you can use __attribute__((unused)) to silence warnings in gcc)

😼 cc --version
cc (GCC) 16.1.1 20260515 (Red Hat 16.1.1-2)

[gvl2023]

The CDT indexer isn't fully compatible with latest standards, so there may be something in included headers that throws it off. I learned to live with red squiggly lines. First step is to filter out indexer markers from the Problems View by not including "Code Analysis Problems" and then just ignore indexer errors in the editor. That said, your project may not be set up correctly or sometimes you can make indexer happy by massaging the includes. I'd start with making sure CDT was able to correctly detect built-in compiler settings. Then create a minimal reproducer - a file that has a single include for string.h and a simple single function with a call to strchr, is it still getting flagged? If not you can try rearranging the includes in your source file and see if it helps. Create a parser log file and see if there are any hints in it. If this was a C++ project and you weren't using modern language features you could try compiling with the C++17 compatibility flag, but since it's C it likely won't help. If everything else fails, consider switching to the LSP editor, this should be a more robust solution thanks to the clangd backend it uses for indexer duties, but the LSP editor experience will be different from the classic CDT C/C++ editor and the Include Browser isn't supported in LSP mode (last time I checked anyway which admittedly has been a while).