1mcs(1) General Commands Manual mcs(1)
2
6 mcs - Mono C# Compiler
7
9 mcs [option] [source-files]
10
12 mcs is the Mono C# compiler, an implementation of the ECMA-334 language
13 specification. You can pass one or more options to drive the compiler,
14 and a set of source files. Extra options or arguments can be provided
15 in a response file. Response files are referenced by prepending the @
16 symbol to the response file name.
17 The mcs compiler is used to compile against the latest Mono Base Class
19 Library version and fully implements C# 1.0, 2.0, 3.0 and 4.0 specifi‐
20 cations.
21 See the section on packages for more information.
23 The Mono C# compiler accepts the same command line options that the Mi‐
25 crosoft C# compiler does. Those options can start with a slash or a
26 dash (/checked is the same as -checked). Additionally some GNU-like
27 options are supported, those begin with "--". All MCS-specific flags
28 which are not available in the Microsoft C# compiler are available only
29 with the GNU-style options.
30 C# source files must end with a ".cs" extension. Compilation of C#
32 source code requires all the files that make up a library, module or
33 executable to be provided on the command line. There is no support for
34 partial compilation. To achieve the benefits of partial compilation,
35 you should compile programs into their own assemblies, and later refer‐
36 ence them with the "-r" flag.
37 The Mono C# compiler generates images (.exe files) that contain CIL
39 byte code that can be executed by any system that implements a Common
40 Language Infrastructure virtual machine such as the Microsoft .NET run‐
41 time engine on Windows or the Mono runtime engine on Unix systems.
42 Executables are not bound to a specific CPU or operating system.
43 The Mono C# compiler by default only references three assemblies:
45 mscorlib.dll, System.dll and System.Xml.dll. If you want to reference
46 extra libraries you must manually specify them using the -pkg: command
47 line option or the -r: command line option. Alternatively if you want
48 to get all of the System libraries, you can use the -pkg:dotnet command
49 line option.
50
52 --about
53 Displays information about the Mono C# compiler
54 --addmodule:MODULE1[,MODULE2]
56 Includes the specified modules in the resulting assembly. Mod‐
57 ules are created by calling the compiler with the -target:module
58 option
59 -checked, -checked+
61 Sets the default compilation mode to `checked'. This makes all
62 the math operations checked (the default is unchecked).
63 -checked-
65 Sets the default compilation mode to `unchecked'. This makes
66 all the math operations unchecked (this is the default).
67 -clscheck-, -clscheck+
69 Disables or enables the Common Language Specification (CLS)
70 checks (it is enabled by default).
71 The Common Language Specification (CLS) defines an interoperable
73 subset of types as well as conventions that compilers (CLS pro‐
74 ducers) and developers must follow to expose code to other pro‐
75 gramming languages (CLS consumers).
76 -codepage:ID
78 Specifies the code page used to process the input files from the
79 point it is specified on. By default files will be processed in
80 the environment-dependent native code page. The compiler will
81 also automatically detect Unicode files that have an embedded
82 byte mark at the beginning.
83 Other popular encodings are 28591 (Latin1), 1252 (iso-8859-1)
85 and 65001 (UTF-8).
86 MCS supports a couple of shorthands: "utf8" can be used to spec‐
88 ify utf-8 instead of using the cryptic 65001 and "reset"
89 restores the automatic handling of code pages. These shorthands
90 are not available on the Microsoft compiler.
91 -define:SYMLIST, -d:SYMLIST
93 Defines the symbol listed by the semi-colon separated list SYM‐
94 LIST SYMBOL. This can be tested in the source code by the pre-
95 processor, or can be used by methods that have been tagged with
96 the Conditional attribute.
97 -debug, -debug+
99 Generate debugging information. To obtain stack traces with
100 debugging information, you need to invoke the mono runtime with
101 the `--debug' flag. The debugging information is stored in a MDB
102 file located in same output folder as produced assembly.
103 -debug-
105 Do not generate debugging information.
106 -delaysign+
108 Only embed the strongname public key into the assembly. The
109 actual signing must be done in a later stage using the SN tool.
110 This is useful to protect the private key during development.
111 Note that delay signing can only be done using a strongname key
112 file (not a key container). The option is equivalent to includ‐
113 ing [assembly: AssemblyDelaySign (true)] in your source code.
114 Compiler option takes precedence over the attributes.
115 -delaysign-
117 Default. Strongname (sign) the assembly using the strong name
118 key file (or container). The option is equivalent to including
119 [assembly: AssemblyDelaySign (false)] in your source code. Com‐
120 piler option takes precedence over the attributes.
121 -doc:FILE
123 Extracts the C#/XML documentation from the source code and
124 stores in in the given FILE.
125 -errorreport
127 This flag is ignored by Mono's C# compiler and is present only
128 to allow MCS to be used as a CSC replacement for msbuild/xbuild.
129 --fatal
131 This is used for debugging the compiler. This makes the error
132 emission generate an exception that can be caught by a debugger.
133 -filealign
135 This flag is ignored by Mono's C# compiler and is present only
136 to allow MCS to be used as a CSC replacement for msbuild/xbuild.
137 -fullpaths
139 Any source code error or warning issued by the compiler includes
140 file name only by default. This option causes compiler to issue
141 absolute file path instead.
142 -keyfile:KEYFILE
144 Strongname (sign) the output assembly using the key pair present
145 in the specified strong name key file (snk). A full key pair is
146 required by default (or when using delaysign-). A file contain‐
147 ing only the public key can be used with delaysign+. The option
148 is equivalent to including [assembly: AssemblyKeyFile ("KEY‐
149 FILE")] in your source code. Compiler option takes precedence
150 over the attributes.
151 -keycontainer:CONTAINER
153 Strongname (sign) the output assembly using the key pair present
154 in the specified container. Note that delaysign+ is ignored when
155 using key containers. The option is equivalent to including
156 [assembly: AssemblyKeyName ("CONTAINER")] in your source code.
157 Compiler option takes precedence over the attributes.
158 -langversion:TEXT
160 The option specifies the version of the language to use. The
161 feature set is different in each C# version. This switch can be
162 used to force the compiler to allow only a subset of the fea‐
163 tures. The possible values are:
164 Default
166 Instruct compiler to use the latest version. Equivalent
167 is to omit the switch (this currently defaults to the C#
168 4.0 language specification).
169 ISO-1 Restrict compiler to use only first ISO standardized fea‐
171 tures. The usage of features such as generics, static
172 classes, anonymous methods will lead to error.
173 ISO-2 Restrict compiler to use only the second ISO standardized
175 features. This allows the use of generics, static
176 classes, iterators and anonymous methods for example.
177 3 Restrict the compiler to use only the features available
179 in C# 3.0 (a superset of ISO-1 and ISO-2).
180 4 Restrict the compiler to use only the features available
182 in C# 4.0 specification.
183 experimental
185 Enables unstable features from upcoming versions of the
186 language.
187 Notice that this flag only restricts the language features
189 available to the programmer. A version of produced assemblies
190 can be controlled using SDK option.
191 -lib:PATHLIST
193 Each path specified in the comma-separated list will direct the
194 compiler to look for libraries in that specified path.
195 -L PATH
197 Directs the compiler to look for libraries in the specified
198 path. Multiple paths can be provided by using the option multi‐
199 ple times.
200 -main:CLASS
202 Tells the compiler which CLASS contains the entry point. Useful
203 when you are compiling several classes with a Main method.
204 -nostdlib, -nostdlib+
206 Use this flag if you want to compile the core library. This
207 makes the compiler load its internal types from the assembly
208 being compiled.
209 -noconfig, -noconfig+
211 Disables the default compiler configuration to be loaded. The
212 compiler by default has references to the system assemblies.
213 -nowarn:WARNLIST
215 Makes the compiler ignore warnings specified in the comma-sepa‐
216 rated list WARNLIST>
217 -optimize, -optimize+, -optimize-
219 Controls compiler code generation optimizations on the code.
220 Using -optimize or -optimize+ will turn on optimizations, -opti‐
221 mize- will turn it off. The default in mcs is to optimize-. The
222 option can be mixed with -debug but for the best debugging expe‐
223 rience it is recommended leave the options off.
224 -out:FNAME, -o FNAME
226 Names the output file to be generated.
227 --parse
229 Used for benchmarking. The compiler will only parse its input
230 files.
231 -pkg:package1[,packageN]
233 Reference assemblies for the given packages.
234 The compiler will invoke pkg-config --libs on the set of pack‐
236 ages specified on the command line to obtain libraries and
237 directories to compile the code.
238 This is typically used with third party components, like this:
240 $ mcs -pkg:gtk-sharp demo.cs
242 -pkg:dotnet
244 This will instruct the compiler to reference the System.*
245 libraries available on a typical dotnet framework instal‐
246 lation, notice that this does not include all of the Mono
247 libraries, only the System.* ones. This is a convenient
248 shortcut for those porting code.
249 -platform:ARCH
251 Used to specify the target platform. The possible values are:
252 anycpu, anycpu32bitpreferred, arm, x86, x64 or itanium. The
253 default option is anycpu.
254 -resource:RESOURCE[,ID]
256 Embeds to the given resource file. The optional ID can be used
257 to give a different name to the resource. If not specified, the
258 resource name will be the file name.
259 -linkresource:RESOURCE[,ID]
261 Links to the specified RESOURCE. The optional ID can be used to
262 give a name to the linked resource.
263 -r:ASSEMBLY1[,ASSEMBLY2], -reference ASSEMBLY1[,ASSEMBLY2]
265 Reference the named assemblies. Use this to use classes from
266 the named assembly in your program. The assembly will be loaded
267 from either the system directory where all the assemblies live,
268 or from the path explicitly given with the -L option.
269 You can also use a semicolon to separate the assemblies instead
271 of a comma.
272 -reference:ALIAS=ASSEMBLY
274 Extern alias reference support for C#.
275 If you have different assemblies that provide the same types,
277 the extern alias support allows you to provide names that your
278 software can use to tell those appart. The types from ASSEM‐
279 BLY will be exposed as ALIAS, then on the C# source code, you
280 need to do:
281 extern alias ALIAS;
283 To bring it into your namespace. For example, to cope with two
284 graphics libraries that define "Graphics.Point", one in
285 "OpenGL.dll" and one in "Postscript.dll", you would invoke the
286 compiler like this:
287 mcs -r:Postscript=Postscript.dll -r:OpenGL=OpenGL.dll
289 And in your source code, you would write:
291 extern alias Postscript;
293 extern alias OpenGL;
294 class X {
296 // This is a Graphics.Point from Postscrip.dll
297 Postscript.Point p = new Postscript.Point ();
298 // This is a Graphics.Point from OpenGL.dll
300 OpenGL.Point p = new OpenGL.Point ();
301 }
302 -recurse:PATTERN, --recurse PATTERN
304 Does recursive compilation using the specified pattern. In Unix
305 the shell will perform globbing, so you might want to use it
306 like this:
307 $ mcs -recurse:'*.cs'
309 -sdk:VERSION
311 Used to specify the version of Base Class Library assemblies
312 used for compilation. Following predefined values are valid: 2,
313 4 (default) as well as any custom value. The predefined version
314 number means which custom value is specified mcs will try to
315 find Base Class Libraries in the mono installed location PRE‐
316 FIX/lib/mono/<value>.
317 --shell
319 Starts up the compiler in interactive mode, providing a C# shell
320 for statements and expressions. A shortcut is to use the
321 csharp command directly.
322 --stacktrace
324 Generates a stack trace at the time the error is reported, use‐
325 ful for debugging the compiler.
326 -target:KIND, -t:KIND
328 Used to specify the desired target. The possible values are:
329 exe (plain executable), winexe (Windows.Forms executable),
330 library (component libraries) and module (partial library).
331 --timestamp
333 Another debugging flag. Used to display the times at various
334 points in the compilation process.
335 -unsafe, -unsafe+
337 Enables compilation of unsafe code.
338 -v Debugging. Turns on verbose yacc parsing.
340 --version
342 Shows the compiler version.
343 -warnaserror, -warnaserror+
345 All compilers warnings will be reported as errors.
346 -warnaserror:W1,[Wn], -warnaserror+:W1,[Wn]
348 Treats one or more compiler warnings as errors.
349 -warnaserror-:W1,[Wn]
351 Sets one or more compiler warnings to be always threated as
352 warnings. Becomes useful when used together with -warnaserror.
353 -warn:LEVEL
355 Sets the warning level. 0 is the lowest warning level, and 4 is
356 the highest. The default is 4.
357 -win32res:FILE
359 Specifies a Win32 resource file (.res) to be bundled into the
360 resulting assembly.
361 -win32icon:FILE
363 Attaches the icon specified in FILE on the output into the
364 resulting assembly.
365 -- Use this to stop option parsing, and allow option-looking param‐
367 eters to be passed on the command line.
368
370 When referencing an assembly, if the name of the assembly is a path,
371 the compiler will try to load the assembly specified in the path. If
372 it does not, then the compiler will try loading the assembly from the
373 current directory, the compiler base directory and if the assembly is
374 not found in any of those places in the directories specified as argu‐
375 ments to the -lib: command argument.
376 The compiler uses the library path to locate libraries, and is able to
378 reference libraries from a particular package if that directory is
379 used. To simplify the use of packages, the C# compiler includes the
380 -pkg: command line option that is used to load specific collections of
381 libraries.
382 Libraries visible to the compiler are stored relative to the installa‐
384 tion prefix under PREFIX/lib/mono/ called the PACKAGEBASE and the
385 defaults for mcs, gmcs and smcs are as follows:
386 mcs References the PACKAGEBASE/1.0 directory
388 gmcs References the PACKAGEBASE/2.0 directory
390 smcs References the PACKAGEBASE/2.1 directory
392 Those are the only runtime profiles that exist. Although other direc‐
394 tories exist (like 3.0 and 3.5) those are not really runtime profiles,
395 they are merely placeholders for extra libraries that build on the 2.0
396 foundation.
397 Software providers will distribute software that is installed relative
399 to the PACKAGEBASE directory. This is integrated into the gacutil tool
400 that not only installs public assemblies into the Global Assembly Cache
401 (GAC) but also installs them into the PACKAGEBASE/PKG directory (where
402 PKG is the name passed to the -package flag to gacutil).
403 As a developer, if you want to consume the Gtk# libraries, you would
405 invoke the compiler like this:
406 $ mcs -pkg:gtk-sharp-2.0 main.cs
408 The -pkg: option instructs the compiler to fetch the definitions for
410 gtk-sharp-2.0 from pkg-config, this is equivalent to passing to the C#
411 compiler the output of:
412 $ pkg-config --libs gtk-sharp-2.0
414 Usually this merely references the libraries from PACKAGEBASE/PKG.
416 Although there are directory names for 3.0 and 3.5, that does not mean
418 that there are 3.0 and 3.5 compiler editions or profiles. Those are
419 merely new libraries that must be manually referenced either with the
420 proper -pkg: invocation, or by referencing the libraries directly.
421
423 The TRACE and DEBUG defines have a special meaning to the compiler.
424 By default calls to methods and properties in the System.Diagnos‐
426 tics.Trace class are not generated unless the TRACE symbol is defined
427 (either through a "#define TRACE") in your source code, or by using the
428 --define TRACE in the command line.
429 By default calls to methods and properties in the System.Diagnos‐
431 tics.Debug class are not generated unless the DEBUG symbol is defined
432 (either through a "#define DEBUG") in your source code, or by using the
433 --define DEBUG in the command line.
434 Note that the effect of defining TRACE and DEBUG is a global setting,
436 even if they are only defined in a single file.
437
439 When using the "-debug" flag, MCS will generate a file with the exten‐
440 sion .mdb that contains the debugging information for the generated
441 assembly. This file is consumed by the Mono debugger (mdb).
442
444 MCS_COLORS
445 If this variable is set, it contains a string in the form "fore‐
446 ground,background" that specifies which color to use to display
447 errors on some terminals.
448 The background is optional and defaults to your terminal current
450 background. The possible colors for foreground are: black,
451 red, brightred, green, brightgreen, yellow, brightyellow, blue,
452 brightblue, magenta, brightmagenta, cyan, brightcyan, grey,
453 white and brightwhite.
454 The possible colors for background are: black, red, green, yel‐
456 low, blue, magenta, cyan, grey and white.
457 For example, you could set these variable from your shell:
459 export MCS_COLORS
460 MCS_COLORS=errors=brightwhite,red
461 You can disable the built-in color scheme by setting this vari‐
463 able to "disable".
464
466 During compilation the MCS compiler defines the __MonoCS__ symbol, this
467 can be used by pre-processor instructions to compile Mono C# compiler
468 specific code. Please note that this symbol is only to test for the
469 compiler, and is not useful to distinguish compilation or deployment
470 platforms.
471
473 The Mono C# Compiler was written by Miguel de Icaza, Ravi Pratap, Mar‐
474 tin Baulig, Marek Safar and Raja Harinath. The development was funded
475 by Ximian, Novell and Marek Safar.
476
478 The Mono Compiler Suite is released under the terms of the GNU GPL or
479 the MIT X11. Please read the accompanying `COPYING' file for details.
480 Alternative licensing for the compiler is available from Xamarin.
481
483 csharp(1), mdb(1), mono(1), mopen(1), pkg-config(1), sn(1)
484
486 To report bugs in the compiler, you must file them on our bug tracking
487 system, at: http://www.mono-project.com/community/bugs/
488
490 The Mono Mailing lists are listed at http://www.mono-project.com/commu‐
491 nity/help/mailing-lists/
492
494 The Mono C# compiler was developed by Novell, Inc (http://www.nov‐
495 ell.com) and Xamarin Inc (http://www.xamarin.com) is based on the ECMA
496 C# language standard available here:
497 http://www.ecma.ch/ecma1/STAND/ecma-334.htm
498 The home page for the Mono C# compiler is at http://www.mono-
500 project.com/docs/about-mono/languages/csharp/
501 6 January 2001 mcs(1)