Qbs Manual | How-tos

Qbs 1.9.1

Custom Modules and Items ◦ Reference

# How-tos

This page provides concrete instructions for common scenarios.

- How do I build a Qt-based project?
- How do I make my app build against my library?
- How do I create application bundles and frameworks on iOS, macOS, tvOS, and watchOS?

## How do I build a Qt-based project?

First of all, your project files need to declare a Qt dependency. See Qt Modules for how to do that.

To build the project, you need a matching profile. The following commands set up and use a Qt-specific profile:

      $ qbs setup-qt /usr/bin/qmake qt
      $ cd my_project
      $ qbs profile:qt

If you plan to use this profile a lot, consider making it the default one:

      $ qbs config defaultProfile qt
      $ cd my_project
      $ qbs

See 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.

## How do I make my app build against my library?

This is achieved by introducing a dependency between the two products using the Depends item. Here is a simple, but complete example:

      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]
             }
          }
      }

The product `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 Export item), so that the source files in these products can include the library's header file.

The product `the-app` is an application that expresses its intent to link against `the-lib` by declaring a dependency on it. Now `main.cpp` can include `lib.h` (because of the exported include path) and the application binary will link against the library (because the linker rule in the 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 Project item's `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.

## 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 Bundle module and setting the `bundle.isBundle` property to `true`.

Here is a simple example for an application:

      import qbs

      Application {
          Depends { name: "cpp" }
          Depends { name: "bundle" }
          bundle.isBundle: true
          name: "the-app"
          files: ["main.cpp"]
      }

and for a framework:

      import qbs

      DynamicLibrary {
          Depends { name: "cpp" }
          Depends { name: "bundle" }
          bundle.isBundle: true
          name: "the-lib"
          files: ["lib.cpp", "lib.h"]
      }

Qbs also supports building static frameworks - you can create one by replacing `DynamicLibrary` with `StaticLibrary` in the example above.

Note: When using the `Application` or `Library` templates (or derived templates like `CppApplication`, `DynamicLibrary`, and `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 `bundle.isBundle` property. Setting the `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 How do I make my app build against my library? section for an example.

Custom Modules and Items ◦ Reference