fails to build with clang/libc++

[markand]

Hello,

I'm trying to build jsoncpp 1.8.4 with clang and libc++.

[5/10] Compiling C++ object 'jsoncpp@sha/src_lib_json_json_writer.cpp.o'.
FAILED: jsoncpp@sha/src_lib_json_json_writer.cpp.o
clang++ -Ijsoncpp@sha -I. -I.. -I../include -Xclang -fcolor-diagnostics -pipe -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -Wnon-virtual
-dtor -O3 -O2 -fPIC -MD -MQ 'jsoncpp@sha/src_lib_json_json_writer.cpp.o' -MF 'jsoncpp@sha/src_lib_json_json_writer.cpp.o.d' -o 'jsoncp
p@sha/src_lib_json_json_writer.cpp.o' -c ../src/lib_json/json_writer.cpp
In file included from ../src/lib_json/json_writer.cpp:7:
In file included from ../include/json/writer.h:10:
In file included from ../include/json/value.h:10:
In file included from ../include/json/forwards.h:10:
In file included from ../include/json/config.h:9:
In file included from /bin/../include/c++/v1/string:505:
In file included from /bin/../include/c++/v1/string_view:176:
In file included from /bin/../include/c++/v1/__string:57:
In file included from /bin/../include/c++/v1/algorithm:640:
In file included from /bin/../include/c++/v1/initializer_list:47:
In file included from /bin/../include/c++/v1/cstddef:38:
../version:1:1: error: expected unqualified-id
1.8.4

To my understanding, cstddef.h from libc++ does #include <version> and therefore includes the filename version in the project directory, which isn't a C++ header file, thus the error.

I don't know how we can fix that correctly though. Renaming that file?

[cdunn2001]

Renaming would be fine. Could you submit a PR for that?

[markand]

Done via #911. I've only tested with clang yet. Is this file used anywhere in the build process?

[cdunn2001]

I don't remember why this file is generated. I think it's ok to rename it. However, I know where it's generated, in CMakeLists.txt:

102 configure_file( "${PROJECT_SOURCE_DIR}/version.in"
103                 "${PROJECT_BINARY_DIR}/version"
104                 NEWLINE_STYLE UNIX )

... Oh, I see where it's used, in dev.makefile, to help sign a release. So rename it there too please.

[BillyDonahue]

That 'version' file should have been harmless. It wasn't in a directory that contains c++ code, so why was the compiler pointed at it? That is, I don't think there was a reason to have -I .. in the compile command. The compiler isn't going to find anything useful there.

I don't know enough about meson to guess where the offending -I .. is coming from, but I suspect we don't want or need it.

[cdunn2001]

https://mesonbuild.com/Include-directories.html

Another thing to note is that include_directories adds both the source directory and corresponding build directory to include path, so you don't have to care.

Not sure, but that seems to indicate Meson does add some -I directories magically. Let's just call it version.txt and be done with it.

[markand]

I don't remember why this file is generated. I think it's ok to rename it. However, I know where it's generated, in CMakeLists.txt:

102 configure_file( "${PROJECT_SOURCE_DIR}/version.in"
103                 "${PROJECT_BINARY_DIR}/version"
104                 NEWLINE_STYLE UNIX )

... Oh, I see where it's used, in dev.makefile, to help sign a release. So rename it there too please.

No, the file version.in is generated in the build directory (aka where you run CMake). The original version file is untouched from CMake (unless you run CMake in the root directory which is harmful).

[eirnym]

Please, make a release with this, as your distro have to be patched to be used this way