The Mono C# compiler accepts the same options than the Microsoft C# compiler does. Those options can start with a slash or a dash (/checked is the same as -checked). Additionally to this, the GNU-like options are supported, those begin with "--". All MCS-specific flags which are not available in the Microsoft C# compiler are available only with the GNU-style options.

C# source files must end with a ".cs" extension. Compilation of C# source code requires all the files that make up a library, module or executable to be provided on the command line. There is no support for partial compilation. To achieve the benefits of partial compilation, you should compile programs into their own assemblies, and later reference them with the "-r" flag.

The Mono C# compiler generates images (.exe files) that contain CIL byte code that can be executed by any system that implements a Common Language Infrastructure virtual machine such as the Microsoft .NET runtime engine on Windows or the Mono runtime engine on Unix systems. Executables are not bound to a specific CPU or operating system.

--about

Displays information about the Mono C# compiler

--addmodule:MODULE1[,MODULE2]

Includes the specified modules in the resulting assembly.

-checked, -checked+

Sets the default compilation mode to `checked'. This makes all the math operations checked (the default is unchecked).

-checked-

Sets the default compilation mode to `unchecked'. This makes all the math operations unchecked (this is the default).

-codepage:ID

Specifies the code page used to process the input files from the point it is specified on. By default files will be processed in the Latin-1 code page. The compiler will also automatically detect Unicode files that have an embedded byte mark at the beginning. The special ID "utf8" can be used to switch to utf8 and the ID "reset" restores the automatic handling of code pages.

-define:SYMLIST, -d:SYMLIST

Defines the symbol listed by the semi-colon separeted list SYMLIST SYMBOL. This can be tested in the source code by the pre-processor, or can be used by methods that have been tagged with the Conditional attribute.

-debug, -debug+, -g

Generate debugging information. To obtain stack traces with debugging information, you need to invoke the mono runtime with the `--debug' flag. This debugging information is stored inside the assembly as a resource.

-debug-

Do not generate debugging information.

-delaysign+

Only embed the strongname public key into the assembly. The actual signing must be done in a later stage using the SN tool. This is useful to protect the private key during development. Note that delay signing can only be done using a strongname key file (not a key container). The option is equivalent to including [assembly: AssemblyDelaySign (true)] in your source code. Compiler option takes precedence over the attributes.

-delaysign-

Default. Strongname (sign) the assembly using the strong name key file (or container). The option is equivalent to including [assembly: AssemblyDelaySign (false)] in your source code. Compiler option takes precedence over the attributes.

--expect-error X L

The compiler will expect the code to generate an error named `X' in line `L'. This is only used by the test suite.

--fatal

This is used for debugging the compiler. This makes the error emission generate an exception that can be caught by a debugger.

-keyfile:KEYFILE

Strongname (sign) the output assembly using the key pair present in the specified strong name key file (snk). A full key pair is required by default (or when using delaysign-). A file containing only the public key can be used with delaysign+. The option is equivalent to including [assembly: AssemblyKeyFile ("KEYFILE")] in your source code. Compiler option takes precedence over the attributes.

-keycontainer:CONTAINER

Strongname (sign) the output assembly using the key pair present in the specified container. Note that delaysign+ is ignored when using key containers. The option is equivalent to including [assembly: AssemblyKeyName ("CONTAINER")] in your source code. Compiler option takes precedence over the attributes.

-lib:PATHLIST

Each path specified in the comma-separated list will direct the compiler to look for libraries in that specified path.

-L PATH

Directs the compiler to look for libraries in the specified path. Multiple paths can be provided by using the option multiple times.

-main:CLASS

Tells the compiler which CLASS contains the entry point. Useful when you are compiling several classes with a Main method.

-nostdlib, -nostdlib+

Use this flag if you want to compile the core library. This makes the compiler load its internal types from the assembly being compiled.

-noconfig, -noconfig+

Disables the default compiler configuration to be loaded. The compiler by default has references to the system assemblies.

-nowarn:WARNLIST

Makes the compiler ignore warnings specified in the comma-separeted list WARNLIST>

-out:FNAME, -o FNAME

Names the output file to be generated.

--parse

Used for benchmarking. The compiler will only parse its input files.

-pkg:package1[,packageN]

The compiler will invoke pkg-config --libs on the set of packages specified on the command line to obtain libraries and directories to compile the code.

This is typically used with third party components, like this:

                $ mcs -pkg:gtk-sharp demo.cs

-resource:RESOURCE[,ID]

Embeds to the given resource file. The optional ID can be used to give a different name to the resource. If not specified, the resource name will be the file name.

-linkresource:RESOURCE[,ID]

Links to the specified RESOURCE. The optional ID can be used to give a name to the linked resource.

-r:ASSEMBLY1[,ASSEMBLY2], -r ASSEMBLY1[,ASSEMBLY2]

Reference the named assemblies. Use this to use classes from the named assembly in your program. The assembly will be loaded from either the system directory where all the assemblies live, or from the path explicitly given with the -L option.

You can also use a semicolon to separate the assemblies instead of a comma.

-recurse:PATTERN, --recurse PATTERN

Does recursive compilation using the specified pattern. In Unix the shell will perform globbing, so you migth want to use it like this:

                $ mcs -recurse:'*.cs'

--stacktrace

Generates a stack trace at the time the error is reported, useful for debugging the compiler.

-target:KIND, -t:KIND

Used to specify the desired target. The possible values are: exe (plain executable), winexe (Windows.Forms executable), library (component libraries) and module (partial library).

--timestamp

Another debugging flag. Used to display the times at various points in the compilation process.

-unsafe, -unsafe+

Enables compilation of unsafe code.

-v

Debugging. Turns on verbose yacc parsing.

-v2

Turns on C# 2.0 language features.

--version

Shows the compiler version.

-warnaserror, -warnaserror+

Treat warnings as errors.

-warn:LEVEL

Sets the warning level. 0 is the lowest warning level, and 4 is the highest. The default is 2.

-win32res:FILE

Specifies a Win32 resource file (.res) to be bundled into the resulting assembly.

-win32icon:FILE

Attaches the icon specified in FILE on the output into the resulting assembly.

--

Use this to stop option parsing, and allow option-looking parameters to be passed on the command line.

By default calls to methods and properties in the System.Diagnostics.Trace class are not generated unless the TRACE symbol is defined (either through a "#define TRACE") in your source code, or by using the --define TRACE in the command line.

By default calls to methods and properties in the System.Diagnostics.Debug class are not generated unless the DEBUG symbol is defined (either through a "#define DEBUG") in your source code, or by using the --define DEBUG in the command line.

Note that the effect of defining TRACE and DEBUG is a global setting, even if they are only defined in a single file.