Including glog/logging.h triggers -Wunused-parameter on g++

[ednolan]

The following script demonstrates the issue:

#!/bin/bash
# install glog to glog_prefix
git clone https://github.com/google/glog.git
mkdir -p glog_prefix
cd glog
mkdir build
cd build
cmake3 -DCMAKE_INSTALL_PREFIX=../../glog_prefix \
       -DCMAKE_BUILD_TYPE=Release \
       -DWITH_GFLAGS=OFF \
       ..
make -j$(nproc --ignore=1)
make install
cd ../..

# build a cpp file that includes glog
cat <<EOF > test.cpp
#include <glog/logging.h>
int main(int, char**) { return 0; }
EOF
g++ -o test -Wall -Wextra -Iglog_prefix/include -Lglog_prefix/lib64 -lglog test.cpp

Expected output: no compiler warning
Actual output:

In file included from test.cpp:1:0:
glog_prefix/include/glog/logging.h:1434:16: warning: unused parameter 'usecs' [-Wunused-parameter]
   virtual void send(LogSeverity severity, const char* full_filename,
                ^

Operating system: CentOS 7.6.1810
gcc version: 4.8.5 (also tested with gcc 8.2.0)

[ednolan]

# install glog to glog_prefix
git clone https://github.com/google/glog.git
mkdir -p glog_prefix
cd glog
mkdir build
cd build
cmake -DCMAKE_INSTALL_PREFIX=../../glog_prefix \
       -DCMAKE_BUILD_TYPE=Release \
       -DWITH_GFLAGS=OFF \
       ..
make -j$(nproc --ignore=1)
make install
cd ../..

# build a cpp file that includes glog
cat <<EOF > test.cpp
#include <glog/logging.h>
int main(int, char**) { return 0; }
EOF
g++ -o test -Wall -Wextra -Iglog_prefix/include -Lglog_prefix/lib -lglog test.cpp

Above is a slightly modified version of the script that triggers the issue on Ubuntu 18.04 LTS with gcc 7.4.0