/**************************************************************************** ** ** Copyright (C) 2017 The Qt Company Ltd. ** Contact: https://www.qt.io/licensing/ ** ** This file is part of Qbs. ** ** $QT_BEGIN_LICENSE:FDL$ ** Commercial License Usage ** Licensees holding valid commercial Qt licenses may use this file in ** accordance with the commercial license agreement provided with the ** Software or, alternatively, in accordance with the terms contained in ** a written agreement between you and The Qt Company. For licensing terms ** and conditions see https://www.qt.io/terms-conditions. For further ** information use the contact form at https://www.qt.io/contact-us. ** ** GNU Free Documentation License Usage ** Alternatively, this file may be used under the terms of the GNU Free ** Documentation License version 1.3 as published by the Free Software ** Foundation and appearing in the file included in the packaging of ** this file. Please review the following information to ensure ** the GNU Free Documentation License version 1.3 requirements ** will be met: https://www.gnu.org/licenses/fdl-1.3.html. ** $QT_END_LICENSE$ ** ****************************************************************************/ /*! \contentspage index.html \previouspage custom-modules.html \nextpage reference.html \page howtos.html \title How-tos This page provides concrete instructions for common scenarios. \list \li \l{How do I build a Qt-based project?} \li \l{How do I make my app build against my library?} \li \l{How do I create a module for a third-party library?} \li \l{How do I create application bundles and frameworks on iOS, macOS, tvOS, and watchOS?} \li \l{How do I apply C/C++ preprocessor macros to only a subset of the files in my product?} \li \l{How do I make the state of my Git repository available to my source files?} \endlist \section1 How do I build a Qt-based project? First of all, your project files need to declare a Qt dependency. See \l{Qt Modules} for how to do that. To build the project, you need a matching \e profile. The following commands set up and use a Qt-specific profile: \code $ qbs setup-qt /usr/bin/qmake qt $ cd my_project $ qbs profile:qt \endcode If you plan to use this profile a lot, consider making it the default one: \code $ qbs config defaultProfile qt $ cd my_project $ qbs \endcode See \l{Managing Qt Versions} for more details. \note These instructions are only relevant for building from the command line. If you use Qt Creator, profiles are set up automatically from the information in the Kit. \section1 How do I make my app build against my library? This is achieved by introducing a \e dependency between the two products using the \l{Depends Item}{Depends item}. Here is a simple, but complete example: \code import qbs Project { CppApplication { name : "the-app" files : [ "main.cpp" ] Depends { name: "the-lib" } } DynamicLibrary { name: "the-lib" Depends { name: "cpp" } files: [ "lib.cpp", "lib.h", ] Export { Depends { name: "cpp" } cpp.includePaths: [product.sourceDirectory] } } } \endcode The product \c the-lib is a dynamic library. It expects other products to build against it, and for that purpose, it exports an include path (via an \l{Export Item}{Export item}), so that the source files in these products can include the library's header file. The product \c the-app is an application that expresses its intent to link against \c the-lib by declaring a dependency on it. Now \c main.cpp can include \c lib.h (because of the exported include path) and the application binary will link against the library (because the linker \l{Rule Item}{rule} in the \l{Module cpp}{cpp module} considers library dependencies as inputs). \note In a non-trivial project, the two products would not be defined in the same file. Instead, you would put them into files of their own and use the \l{Project Item}{Project item}'s \c references property to pull them into the project. The product definitions would stay exactly the same. In particular, their location in the project tree is irrelevant to the relationship between them. \section1 How do I create a module for a third-party library? If you have pre-built binary files in your source tree, you can create modules for them and then introduce dependencies between your project and the modules to pull in the functionality of a third-party library. Create the following folder structure to store the module files: \code $projectroot/modules/ThirdParty \endcode Then create a file in the directory that specifies the module properties for each supported toolchain. The filename must have the \c .qbs extension. The module will be pulled in if a product declares a dependency on it. In the following example, \c lib1.dylib is a multi-architecture library containing both 32-bit and 64-bit code. \code ---ThirdParty.qbs--- Module { Depends { name: "cpp" } cpp.includePaths: ["/somewhere/include"] Properties { condition: qbs.targetOS.contains("android") cpp.dynamicLibraries: ["/somewhere/android/" + Android.ndk.abi + "/lib1.so"] } Properties { condition: qbs.targetOS.contains("macos") cpp.dynamicLibraries: ["/somewhere/macos/lib1.dylib"] } Properties { condition: qbs.targetOS.contains("windows") && qbs.architecture === "x86" cpp.dynamicLibraries: ["/somewhere/windows_x86/lib1.lib"] } Properties { condition: qbs.targetOS.contains("windows") && qbs.architecture === "x86_64" cpp.dynamicLibraries: ["/somewhere/windows_x86_64/lib1.lib"] } } \endcode Finally, declare dependencies on \c ThirdParty in your project: \code import qbs CppApplication { name: "the-app" files: ["main.cpp"] Depends { name: "ThirdParty" } } \endcode \section1 How do I create application bundles and frameworks on iOS, macOS, tvOS, and watchOS? Creating an application bundle or framework is achieved by introducing a dependency on the \l{Module bundle}{Bundle module} and setting the \c bundle.isBundle property to \c true. Here is a simple example for an application: \code import qbs Application { Depends { name: "cpp" } Depends { name: "bundle" } bundle.isBundle: true name: "the-app" files: ["main.cpp"] } \endcode and for a framework: \code import qbs DynamicLibrary { Depends { name: "cpp" } Depends { name: "bundle" } bundle.isBundle: true name: "the-lib" files: ["lib.cpp", "lib.h"] } \endcode \QBS also supports building static frameworks - you can create one by replacing \c DynamicLibrary with \c StaticLibrary in the example above. \note When using the \c Application or \c Library templates (or derived templates like \c CppApplication, \c DynamicLibrary, and \c StaticLibrary), your products will build as bundles on Apple platforms by default (this behavior is subject to change in a future release). To explicitly control whether your product is built as a bundle, set the \c bundle.isBundle property. Setting the \c consoleApplication property of your product will also influence whether your product is built as a bundle. Building your application against your framework is the same as linking a normal dynamic or static library; see the \l{How do I make my app build against my library?} section for an example. \section1 How do I apply C/C++ preprocessor macros to only a subset of the files in my product? Use a \l{Group Item}{Group item} to define a subset of project files. To add macros within the group, you need to use the \c outer.concat property, because you are adding macros to those specified in the outer scope. In the following example, \c MACRO_EVERYWHERE is defined for all files in the \l{Product Item}{Product} unless a \c Group overrides the macro, whereas \c MACRO_GROUP is only defined for \c groupFile.cpp. \code Product { Depends { name: "cpp" } cpp.defines: ["MACRO_EVERYWHERE"] Group { cpp.defines: outer.concat("MACRO_GROUP") files: "groupFile.cpp" } } \endcode The \c cpp.defines statements inside a \c Group only apply to the files in that \c Group, and therefore you cannot use a \c Group to include a bunch of files and globally visible macros. The macros must be specified in a \l{Properties Item}{Properties item} at the same level as the \c Group if they need to be visible to files outside the \c Group: \code Product { Depends { name: "cpp" } Group { condition: project.supportMyFeature files: "myFile.cpp" } property stringList commonDefines: ["ONE", "TWO"] Properties { condition: project.supportMyFeature cpp.defines: commonDefines.concat("MYFEATURE_SUPPORTED") } } \endcode \section1 How do I make the state of my Git repository available to my source files? Add a dependency to the \c vcs module to your product: \code CppApplication { // ... Depends { name: "vcs" } // ... } \endcode Your source files will now have access to a macro whose value is a string representing the current Git or Subversion HEAD: \code #include #include int main() { std::cout << "I was built from " << VCS_REPO_STATE << std::endl; } \endcode This value is also available via a module property in \QBS project files. See the \l{Module vcs}{vcs module documentation} for details. */