os_defines.h:44:19: error: missing binary operator before token "("

[joxeankoret]

Hi!

I'm trying to build an old Intel PIN tool using the current GitHub's version of the single include file json.hpp. I noticed that it fails building in my system (Ubuntu 16.04 x86_64, tested with g++ 5.0 and 4.9). This the very first error I get:

In file included from /usr/include/x86_64-linux-gnu/c++/5/bits/c++config.h:482:0,
                 from /usr/include/c++/5/initializer_list:41,
                 from json.hpp:41,
                 from Tracer.h:24,
                 from Tracer.cpp:5:
/usr/include/x86_64-linux-gnu/c++/5/bits/os_defines.h:44:19: error: missing binary operator before token "("
 #if __GLIBC_PREREQ(2,15) && defined(_GNU_SOURCE)
                   ^

I tried including features.h before "json.hpp", defining myself __GLIBC_PREREQ to trick it, but it fails in other ways, so I guess I'm doing something wrong :)

Any ideas?

[theodelrieu]

Could you try to apply a patch similar to this one?

[joxeankoret]

@theodelrieu I honestly don't know how to apply a similar patch. That patch is changing directly the part where that macros were used. In my case it's failing at a standard include file.

[theodelrieu]

Oh sorry I thought this was in the library's code... This SO post looks a lot like your issue, maybe it can help?

[joxeankoret]

I tried most of the workarounds there: None worked for me. Before opening an issue I actually tried applying workarounds from that Stack Overflow's post, as it's the very first Google result. Alas, it didn't work for me.

[theodelrieu]

Hmm, seems that including <initializer_list> on your system breaks. What is the stdlibc++ version you're linking against?

EDIT: I guess it's 5.0. Could you write a program which only includes <initializer_list>? It might be one of your compiler flags.

[joxeankoret]

Nope, that's not the problem (I would have noticed it long ago, as I do code a lot in C++):

$ cat kk.cpp 
#include <initializer_list>

void foo(void) {}

$ g++ -c kk.cpp -o kk -std=c++11
(No error)
$ g++ -v 2>&1 | tail -1
gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.6) 

I tried with every GCC versions I have:

$ g++-4.8 -c kk.cpp -o kk -std=c++11
(No error)
$ g++-4.9 -c kk.cpp -o kk -std=c++11
(No error)
$ g++-5 -c kk.cpp -o kk -std=c++11
(No error)

[theodelrieu]

And only including <nlohmann/json.hpp> breaks?

[joxeankoret]

No, I tried with another old project where I use it (a rather complex one) and everything builds OK. It seems the problem is specific to Intel PIN's headers. If I try to build the most simple of the Intel PIN tools (just enter into $DIR/source/tools/MyPinTool and type 'make'), it compiles OK, but as soon as I include "json.hpp" in MyPinTool.cpp, it breaks. It didn't before with previous versions of Intel PIN. I wonder why...

[theodelrieu]

And including <initializer_list> with Intel PIN's headers break, right?

I've looked at this issue, and it might be related to your problem (if Intel fiddles with glibc headers).

I have no notion of Intel PIN, so I'm afraid I won't be very helpful here :/

[joxeankoret]

Yes, you're right, by simply adding that include file it breaks. Thanks a lot for the help!

[theodelrieu]

I wish you good luck!

[nlohmann]

So this is not an issue of this library (other than it including <initializer_list>?

[joxeankoret]

Nope, my issue has nothing to do with this library. I'm closing the issue. Again, thanks for the help!

[standupforyourself]

No, I tried with another old project where I use it (a rather complex one) and everything builds OK. It seems the problem is specific to Intel PIN's headers. If I try to build the most simple of the Intel PIN tools (just enter into $DIR/source/tools/MyPinTool and type 'make'), it compiles OK, but as soon as I include "json.hpp" in MyPinTool.cpp, it breaks. It didn't before with previous versions of Intel PIN. I wonder why...

---

I had the same issue yesterday. and I solved it by setting CPLUS_INCLUDE_PATH to the right value, it was "/usr/include/jsoncpp/json" which was wrong, the right value should be "/usr/include/jsoncpp".