Adding C++11

This build consists of a 'Hello World' program, written in C++11.

This build uses the code of https://github.com/richelbilderbeek/travis_qmake_gcc_cpp11.

What is C++11?

C++11 is a C++ standard finalized in 2011.

Cross compiling

The cross compiling script looks like this:

#!/bin/bash
cd travis_qmake_gcc_cpp11

# Remove all warnings
sed -i 's/^QMAKE_CXXFLAGS = -W/# QMAKE_CXXFLAGS = -W/' travis_qmake_gcc_cpp11.pro
# Remove use of compiler and linker 
sed -i 's/^QMAKE_CXX /# QMAKE_CXX /' travis_qmake_gcc_cpp11.pro
sed -i 's/^QMAKE_LINK/# QMAKE_LINK/' travis_qmake_gcc_cpp11.pro
sed -i 's/^QMAKE_CC/# QMAKE_CC/' travis_qmake_gcc_cpp11.pro

i686-w64-mingw32.static-qmake-qt5

make

cd ..

if [ ! -f ./travis_qmake_gcc_cpp11/release/travis_qmake_gcc_cpp11.exe ]
then
  echo "Error: Windows executable has not been created"
  exit 1
fi

It has the following elements:

• #!/bin/bash: the shebang, indicating this is a bash script
• cd travis_qmake_gcc_cpp11: go into the folder travis_qmake_gcc_cpp11
• # Remove all warnings: a comment. All comments start with a pound (#)
• sed -i 's/^QMAKE_CXXFLAGS += -W/# QMAKE_CXXFLAGS += -W/' travis_qmake_gcc_cpp11.pro: comment out all lines that start with QMAKE_CXXFLAGS += -W. This to remove all the warnings
• sed -i 's/^QMAKE_CXX /# QMAKE_CXX /' travis_qmake_gcc_cpp11.pro: comment out all lines that start with QMAKE_CXX
• i686-w64-mingw32.static-qmake-qt5: create a makefile for the only .pro file in that folder using Qt5's qmake
• make: build the executable
• cd ..: go up one folder

if [ ! -f ./travis_qmake_gcc_cpp11/release/travis_qmake_gcc_cpp11.exe ]
then
  echo "Error: Windows executable has not been created"
fi

• if the executable file does not exist, then show an error message and exit the script with an error code

The executable is put into a folder called release. You may not have expected that: usually code ends up in a debug folder. Then, remember that you cross compile: your debugger cannot handle a Windows executable.

The project file used for this cross-compile is rather strict: all warnings are turned on, and warnings are escalated to errors. This may be inappropriate for cross-compiling: your code has been tested on your favorite platform (if not, you should), and you may choose to ignore warnings. This script comments out all such warnings.