error "<glog/logging.h> was not included correctly." in including glog in c++ program

Question

I have an error in including <glog/logging.h>.

My program is (test.cc):

#include <glog/logging.h>

int main(int argc, char* argv[]) {
    // Initialize Google’s logging library.
    google::InitGoogleLogging(argv[0]);

    // ...
    LOG(INFO) << "Found cookies";
}

only it!

And my CMakeLists.txt is:

cmake_minimum_required (VERSION 3.16)
project (myproj VERSION 1.0)

find_package (glog 0.6.0 REQUIRED)

add_executable (myapp test.cc)
target_link_libraries (myapp glog::glog)

Also errors are:

[build] In file included from /home/smh/Documents/projects/hist/hist/src/hist.cc:4:
[build] /usr/local/include/glog/logging.h:60:4: error: #error <glog/logging.h> was not included correctly. See the documention for how to consume the library.
[build]    60 | #  error <glog/logging.h> was not included correctly. See the documention for how to consume the library.
[build]       |    ^~~~~
[build] In file included from /usr/local/include/glog/logging.h:63,
[build]                  from /home/smh/Documents/projects/hist/hist/src/hist.cc:4:
[build] /usr/local/include/glog/flags.h:45:4: error: #error <glog/flags.h> was not included correctly. See the documention for how to consume the library.
[build]    45 | #  error <glog/flags.h> was not included correctly. See the documention for how to consume the library.
[build]       |    ^~~~~
[build] In file included from /usr/local/include/glog/logging.h:77,
[build]                  from /home/smh/Documents/projects/hist/hist/src/hist.cc:4:
[build] /usr/local/include/glog/log_severity.h:38:4: error: #error <glog/log_severity.h> was not included correctly. See the documention for how to consume the library.
[build]    38 | #  error <glog/log_severity.h> was not included correctly. See the documention for how to consume the library.
[build]       |    ^~~~~
[build] In file included from /usr/local/include/glog/logging.h:78,
[build]                  from /home/smh/Documents/projects/hist/hist/src/hist.cc:4:
[build] /usr/local/include/glog/vlog_is_on.h:71:4: error: #error <glog/vlog_is_on.h> was not included correctly. See the documention for how to consume the library.
[build]    71 | #  error <glog/vlog_is_on.h> was not included correctly. See the documention for how to consume the library.
[build]       |    ^~~~~
[build] In file included from /usr/local/include/glog/logging.h:63,
[build]                  from /home/smh/Documents/projects/hist/hist/src/hist.cc:4:
[build] /usr/local/include/glog/flags.h:105:1: error: ‘GLOG_EXPORT’ does not name a type
[build]   105 | DECLARE_int32(logemaillevel);
[build]       | ^~~~~~~~~~~~~
[build] /usr/local/include/glog/flags.h:105:1: error: ‘FLAGS_logemaillevel’ has not been declared in ‘fLI’
[build]   105 | DECLARE_int32(logemaillevel);
[build]       | ^~~~~~~~~~~~~
[build] /usr/local/include/glog/flags.h:106:1: error: ‘GLOG_EXPORT’ does not name a type
[build]   106 | DECLARE_int32(logcleansecs);
[build]       | ^~~~~~~~~~~~~
[build] /usr/local/include/glog/flags.h:106:1: error: ‘FLAGS_logcleansecs’ has not been declared in ‘fLI’
[build]   106 | DECLARE_int32(logcleansecs);
[build]       | ^~~~~~~~~~~~~
...

I installed glog from its README in github and all its tests were successful. text

And I installed this: text

Please help me.

Answer 1

It's looks like you are using it on Windows, without specify how to use the DLL or library. What is causing it is the following section in the header file:

#if !defined(GLOG_EXPORT) || !defined(GLOG_NO_EXPORT)
#  error <glog/logging.h> was not included correctly. See the documention for how to consume the library.
#endif

In other words: need to add a definition to CMake add_definitions(-DGLOG_NO_EXPORT) if you are using glog as a static lib, or add_definitions(-DGLOG_USE_GLOG_EXPORT) if glog is a DLL.

If you built glog by yourself, make sure you set the appropriate swiches.

Answer 2

Unless you are building glog library the simplest solution is to compile with

#define GLOG_USE_GLOG_EXPORT

It will include pltform specific file generated during installation. This file will define GLOG_EXPORT and GLOG_NO_EXPORT as appropriate.