Home > Articles

Introducing C#

  • Print
  • + Share This
This chapter is from the book

This chapter is from the book

The C# Compiler

After that introduction to C# and object orientation in general, it's time to see how C# projects can be compiled. In this section, you learn how to compile more than just one file and how various classes can be combined.

Compiling

Before you see how compiling works, we'll guide you through the steps of the compilation process itself.

The first thing to do is to call the lexer, which prepares tokens for the parser. In the case of Mono, the parser is based on Jay, a Java-based Berkley Port of Yacc. Miguel de Icaza ported Jay to C#. Tokens are code fragments that the system needs for checking the syntax. The syntax check is performed by a parser.

After creating a parse tree, the system starts to look for parent classes and tries to find out more about the meaning of the code. Before this step, the system knows about the code but it does not know what it means yet. A semantic analysis of the data leads to the final code. Therefore, Mono uses the System.Reflection.Emit API.

Compiling More Than Just One File

Compiling a set of files is slightly more complex than compiling just one piece of code. Huge projects are usually not implemented in one file. Therefore, it makes sense to combine multiple source files in one project and to compile the entire code with just one step.

This section teaches you the most basic fundamentals.

To see how things work, we start with an example consisting of just two files. Let's have a look at human.cs:

using System;

public class  Human
{
    public Human()
    {
        Console.WriteLine("a child without name ...");
    }

    public Human(string name)
    {
        Console.WriteLine(name + " is born ...");
    }
}

Now let's see what we can find in main.cs:

class  Demo
{
    public static void Main()
    {
        Human paul = new Human();
        Human hugo = new Human("Hugo");
    }
}

If we have a closer look at those two files, we'll find out that we include only Human—the System namespace isn't included because we need it inside our classes anyway.

To compile the code, we can use the following command:

[hs@duron mono]$ mcs /optimize main.cs human.cs /out:human.exe
Compilation succeeded

Just list all files in a single command line. To define which file to create, just use /out:. Older versions of Mono supported the -o flag as well, but we recommend using the newer syntax. In our case, the output is sent to human.exe. With the help of /optimize, we tell the C# compiler to optimize the output.

As you can see in the listing, the output can be called just like always:

[hs@duron mono]$ mono human.exe
a child without name ...
Hugo is born ...

In this example, the entire code has been transformed to one big EXE file. However, it's often useful to compile objects as separate modules. This is no problem for the C# compiler. In the case of Mono, DLL files are used. To generate a DLL, just do as we've done in the following listing:

[hs@duron mono]$ mcs --target library /out:human.dll human.cs
Compilation succeeded

Now that the DLL has been created, we can take it and compile the main program;

[hs@duron mono]$ mcs -L . -reference:human.dll ex.cs
Compilation succeeded

The process will lead to the desired result:

[hs@duron mono]$ mono ex.exe
a child without name ...
Hugo is born ...

The more complex your application, the more important it is to make use of modules and DLL files.

Compiler Flags

In this section, we deal with the most important flags of the C# compiler. The syntax of mcs is comparatively simple:

mcs [option] [source-files]

The next section contains an overview of the parameters supported by mcs:

[hs@duron mono]$ mcs --help
Mono C# compiler, (C) 2001 Ximian, Inc.
mcs [options] source-files
  --about           About the Mono C# compiler
  -checked[+|-]     Set default context to checked
  -codepage:ID      Sets code page to the one in ID
                    (number, 'utf8' or 'reset')
  -define:S1[;S2]   Defines one or more symbols (short: /d:)
  -debug[+-]        Generate debugging information
  -g                Generate debugging information
  --fatal           Makes errors fatal
  -lib:PATH1,PATH2  Adds the paths to the assembly link path
  -main:class       Specified the class that contains the entry point
  -noconfig[+|-]    Disables implicit references to assemblies
  -nostdlib[+|-]    Does not load core libraries
  -nowarn:W1[,W2]   Disables one or more warnings
  -out:FNAME        Specifies output file
  --parse           Only parses the source file
  --expect-error X  Expect that error X will be encountered
  -recurse:SPEC     Recursively compiles the files in SPEC ([dir]/file)
  -reference:ASS    References the specified assembly (-r:ASS)
  --stacktrace      Shows stack trace at error location
  -target:KIND      Specifies the target (KIND is one of: exe, winexe,
                    library, module), (short: /t:)
  --timestamp       Displays time stamps of various compiler events
  -unsafe[+|-]      Allows unsafe code
  -warnaserror[+|-] Treat warnings as errors
  -warn:LEVEL       Sets warning level (the highest is 4, the default)
  -v                Verbose parsing (for debugging the parser)

Resources:
  -linkresource:FILE[,ID] Links FILE as a resource
  -resource:FILE[,ID]     Embed FILE as a resource
  --mcs-debug X   Sets MCS debugging level to X
  @file           Read response file for more options

Options can be of the form -option or /option

The listing was generated with the help of mcs 0.23. As you can see in the last line, the compiler supports Unix and .NET-style options. However, we recommend sticking to the .NET-compliant options.

  • + Share This
  • 🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.

Overview


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information


To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information


Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children


This site is not directed to children under the age of 13.

Marketing


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information


If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information


Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents


California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure


Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact


Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice


We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020