Welcome!

Microsoft Cloud Authors: Nick Basinger, Kevin Benedict, Pat Romanski, Liz McMillan, Lori MacVittie

Related Topics: Microsoft Cloud

Microsoft Cloud: Article

MSBuild - What It Does and What You Can Expect in the Future

The standard customizable build platform for the .NET Framework

In Visual Studio 2003 and earlier, the build process for Visual Basic and C# projects was hard-coded, and built into Visual Studio itself. The only build scripting tool that Microsoft offered was nmake, and a companion tool called build.exe that provided some support for concurrent builds. Visual Studio users whose build systems were based on makefiles had to maintain project files in parallel. For Visual Studio 2005, we thought it would be great if it was possible to completely customize the build process, and to build Visual Studio projects on machines that didn't even have Visual Studio installed, exactly the same as they built inside Visual Studio. We also wanted to be able to plug in reuseable build loggers and build steps.

MSBuild shipped in .NET Framework 2.0, and Visual Studio 2005 was based on it. To date we've only released build processes for Visual Basic and C#, but our vision is to make this truly the common build platform for Microsoft technologies. It's fair to say that internal Microsoft needs have motivated MSBuild almost as much as the needs of our customers. We're making exciting progress towards this goal, and we'll talk about our future plans later in this article.

MSBuild File Format
If you use Visual Studio 2005, you don't necessarily have to know anything about MSBuild syntax. Visual Studio's Visual Basic and C# project files are MSBuild format, and you can go right ahead and build them on machines without Visual Studio installed.

However if you want to customize the build process or create your own from scratch, you'll need to know something about the MSBuild syntax. We tried to make the file format as simple as possible, so it's easy to learn. It's XML, so any XML tool can work with it, and there are only a few different tags to know about. Let's do a quick tour.

PROPERTIES
MSBuild properties represent key/value pairs used during the build process. A property can only take one value at a time. Properties are always inside a PropertyGroup tag. If you open a Visual Basic or C# project file you'll see it uses properties to store whether the compiler should build with optimizations (the "Optimize" property), the output path (the "OutputPath" property), and what warning level it should use (the WarningLevelproperty). Think of properties as scalars. You can get their values with an expression like "$(PropertyName)".

ITEMS
MSBuild Item lists are just ordered bags, like arrays. An item list contains multiple MSBuild items of the same type. Each has a value and optional metadata. The syntax to access their values is different than properties: "@(ItemType)." The items in an item list are often file paths, but don't have to be - MSBuild doesn't care. Take a look at a Visual Basic or C# project again and you'll see items used to store all the source files (the "Compile" items) and references (the "Reference" items) in your project. They don't have to be hard-coded though. You can have MSBuild generate a list of items using wildcards such as "*.txt".

Like properties, items have an ItemGroup tag they always sit inside. Unlike properties, items can have arbitrary "metadata" attached to each one, which you can define with sub-elements below the item's element. Here's an example of metadata used to represent a Culture value on a resource item:

<ItemGroup>
   <Resource Include="Form1.en-CA.resx ">
     <Culture>en-CA</Culture>
   </Resource>
</ItemGroup>

Metadata is accessed with yet another kind of expression that looks like this "%(MetadataName)" or "%(ItemType.MetadataName)". There's also a variety of built-in metadata such as "Filename" and "Full-Path", which are useful if the item represents a file.

One item list can be converted to another by a transform operation. For example, if you write "@(Compile -> ‘%(Filename).obj'") you'll get the collection of "Compile" items, but the extension of each item will be changed to "obj". That can be useful for specifying the outputs of a target or constructing a command line string.

TARGETS
Targets are the unit of build: it's not possible to build only part of a target. This time open up your Microsoft.CSharp.targets file, which you'll find in the .NET Framework install folder, e.g., Windows\ Microsoft.NET\Framework\v2.0.50727. (By convention, targets are stored in files that have the ‘.targets' extension.) Now look for the ‘Target' tag. A target groups a collection of tasks together in a particular order to form a unit of build. For example, the "CoreCompile" target contains the "CSC" task that will invoke the C# compiler. Like every other MSBuild tag, Target tags can have conditions on them, but you can also add Input and Output attributes, which MSBuild will compare to see if the target is up-to-date already: if the target is up-todate, MSBuild will skip the tasks within it in part or entirely. A "DependsOnTargets" attribute lets you define what targets need to run beforehand so you can organize the order in which targets run. Targets can override previous targets with the same name. Targets have some other powers: partial incremental build and target batching; you can find out more about these on MSDN.

TASKS
Tasks are reuseable build actions that define the steps in a target. Tasks are always inside a target. Each task is implemented as a .NET class, and the parameters to a task - where you pass in the items and properties it needs - are just the .NET properties on that task. MSBuild comes with a set of built-in tasks like Delete, Message, GenerateResource (which is much like resgen.exe), plus tasks for the Visual Basic and C# compilers. There's also a special MSBuild task that runs MSBuild on another project. If those aren't enough, you can write your own - start by deriving from Task or ToolTask. Use a "UsingTask" tag to help MSBuild to find the assembly that implements your task. Tasks can also emit items and properties back into the build using Output sub-elements for subsequent tasks and targets to consume.

CONDITIONS
Every element in MSBuild syntax can have a Condition attribute. These have simple syntax something like conditions in XSL: logical operators "and", "or". parentheses, and so on. You can also use Choose, When, and Otherwise elements to make decisions. Here are some examples, so you can see what they look like:

<Compile Include="MyFile.cs" Condition="'$(Confi guration)'=='debug'"/>

In this example, the item "MyFile.cs" will be created only when the project is building in the debug configuration.

<Target Name="CreateOutputDirectory" Condition="!Exists(‘$(OutputDir)')" />

In this example, the target CreateOutputDirectory and the targets it depends on will run only if the output directory doesn't exist.


More Stories By Xin Yan

Xin Yan has been a software design engineer at Microsoft for over 7 years. He works on Visual Studio developer tools platform team.

More Stories By Dan Moseley

Dan Moseley is a software developer on the MSBuild and Visual Studio Project team.

Comments (1) View Comments

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


Most Recent Comments
Paul 11/28/07 04:17:42 PM EST

I enjoyed the article on MSBuild, well written, concise, and interesting. But I was most interested in reading about Batching. In that section, you refer to an example using the Culture metadata, but I don't see the example you're referring to. Am I missing something?

IoT & Smart Cities Stories
Digital Transformation and Disruption, Amazon Style - What You Can Learn. Chris Kocher is a co-founder of Grey Heron, a management and strategic marketing consulting firm. He has 25+ years in both strategic and hands-on operating experience helping executives and investors build revenues and shareholder value. He has consulted with over 130 companies on innovating with new business models, product strategies and monetization. Chris has held management positions at HP and Symantec in addition to ...
DXWorldEXPO LLC announced today that Big Data Federation to Exhibit at the 22nd International CloudEXPO, colocated with DevOpsSUMMIT and DXWorldEXPO, November 12-13, 2018 in New York City. Big Data Federation, Inc. develops and applies artificial intelligence to predict financial and economic events that matter. The company uncovers patterns and precise drivers of performance and outcomes with the aid of machine-learning algorithms, big data, and fundamental analysis. Their products are deployed...
Dynatrace is an application performance management software company with products for the information technology departments and digital business owners of medium and large businesses. Building the Future of Monitoring with Artificial Intelligence. Today we can collect lots and lots of performance data. We build beautiful dashboards and even have fancy query languages to access and transform the data. Still performance data is a secret language only a couple of people understand. The more busine...
The challenges of aggregating data from consumer-oriented devices, such as wearable technologies and smart thermostats, are fairly well-understood. However, there are a new set of challenges for IoT devices that generate megabytes or gigabytes of data per second. Certainly, the infrastructure will have to change, as those volumes of data will likely overwhelm the available bandwidth for aggregating the data into a central repository. Ochandarena discusses a whole new way to think about your next...
CloudEXPO | DevOpsSUMMIT | DXWorldEXPO are the world's most influential, independent events where Cloud Computing was coined and where technology buyers and vendors meet to experience and discuss the big picture of Digital Transformation and all of the strategies, tactics, and tools they need to realize their goals. Sponsors of DXWorldEXPO | CloudEXPO benefit from unmatched branding, profile building and lead generation opportunities.
All in Mobile is a place where we continually maximize their impact by fostering understanding, empathy, insights, creativity and joy. They believe that a truly useful and desirable mobile app doesn't need the brightest idea or the most advanced technology. A great product begins with understanding people. It's easy to think that customers will love your app, but can you justify it? They make sure your final app is something that users truly want and need. The only way to do this is by ...
Cell networks have the advantage of long-range communications, reaching an estimated 90% of the world. But cell networks such as 2G, 3G and LTE consume lots of power and were designed for connecting people. They are not optimized for low- or battery-powered devices or for IoT applications with infrequently transmitted data. Cell IoT modules that support narrow-band IoT and 4G cell networks will enable cell connectivity, device management, and app enablement for low-power wide-area network IoT. B...
The hierarchical architecture that distributes "compute" within the network specially at the edge can enable new services by harnessing emerging technologies. But Edge-Compute comes at increased cost that needs to be managed and potentially augmented by creative architecture solutions as there will always a catching-up with the capacity demands. Processing power in smartphones has enhanced YoY and there is increasingly spare compute capacity that can be potentially pooled. Uber has successfully ...
SYS-CON Events announced today that CrowdReviews.com has been named “Media Sponsor” of SYS-CON's 22nd International Cloud Expo, which will take place on June 5–7, 2018, at the Javits Center in New York City, NY. CrowdReviews.com is a transparent online platform for determining which products and services are the best based on the opinion of the crowd. The crowd consists of Internet users that have experienced products and services first-hand and have an interest in letting other potential buye...
When talking IoT we often focus on the devices, the sensors, the hardware itself. The new smart appliances, the new smart or self-driving cars (which are amalgamations of many ‘things'). When we are looking at the world of IoT, we should take a step back, look at the big picture. What value are these devices providing. IoT is not about the devices, its about the data consumed and generated. The devices are tools, mechanisms, conduits. This paper discusses the considerations when dealing with the...