1RUSTC(1)                         User Commands                        RUSTC(1)
2
3
4

NAME

6       rustc - The Rust compiler
7

SYNOPSIS

9       rustc [OPTIONS] INPUT
10
11

DESCRIPTION

13       This  program  is  a  compiler  for  the  Rust  language,  available at
14       https://www.rust-lang.org.
15
16

OPTIONS

18       -h, --help
19              Display the help message.
20
21       --cfg SPEC
22              Configure the compilation environment.
23
24       -L [KIND=]PATH
25              Add a directory to the library search path.  The  optional  KIND
26              can be one of:
27
28              dependency
29                     only lookup transitive dependencies here
30
31              crate  only lookup local `extern crate` directives here
32
33              native only lookup native libraries here
34
35              framework
36                     only look for OSX frameworks here
37
38              all    look for anything here (the default)
39
40       -l [KIND=]NAME
41              Link  the generated crate(s) to the specified library NAME.  The
42              optional KIND can be one of static,  dylib,  or  framework.   If
43              omitted, dylib is assumed.
44
45       --crate-type [bin|lib|rlib|dylib|cdylib|staticlib]
46              Comma  separated  list  of  types  of crates for the compiler to
47              emit.
48
49       --crate-name NAME
50              Specify the name of the crate being built.
51
52       --emit [asm|llvm-bc|llvm-ir|obj|link|dep-info|mir][=PATH]
53              Configure the output that rustc will produce. Each emission  may
54              also  have  an  optional explicit output PATH specified for that
55              particular emission kind. This path takes precedence over the -o
56              option.
57
58       --print [crate-name|file-names|sysroot|cfg|target-list|target-cpus|tar‐
59       get-features|relocation-models|code-models|tls-models|target-spec-json|
60       native-static-libs]
61              Comma separated list of compiler information to print on stdout.
62
63       -g     Equivalent to -C debuginfo=2.
64
65       -O     Equivalent to -C opt-level=2.
66
67       -o FILENAME
68              Write output to FILENAME. Ignored if multiple --emit outputs are
69              specified which don't have an explicit path otherwise.
70
71       --out-dir DIR
72              Write output to compiler‐chosen filename in DIR. Ignored  if  -o
73              is specified.  Defaults to the current directory.
74
75       --explain OPT
76              Provide a detailed explanation of an error message.
77
78       --test Build a test harness.
79
80       --target TARGET
81              Target  triple  for  which  the  code  is  compiled. This option
82              defaults to the host’s target triple. The target triple has  the
83              general format <arch><sub>-<vendor>-<sys>-<abi>, where:
84
85              <arch> x86, arm, thumb, mips, etc.
86
87              <sub>  for example on ARM: v5, v6m, v7a, v7m, etc.
88
89              <vendor>
90                     pc, apple, nvidia, ibm, etc.
91
92              <sys>  none, linux, win32, darwin, cuda, etc.
93
94              <abi>  eabi, gnu, android, macho, elf, etc.
95
96       -W help
97              Print 'lint' options and default settings.
98
99       -W OPT, --warn OPT
100              Set lint warnings.
101
102       -A OPT, --allow OPT
103              Set lint allowed.
104
105       -D OPT, --deny OPT
106              Set lint denied.
107
108       -F OPT, --forbid OPT
109              Set lint forbidden.
110
111       -C FLAG[=VAL], --codegen FLAG[=VAL]
112              Set  a codegen‐related flag to the value specified.  Use -C help
113              to print available flags.  See CODEGEN OPTIONS below.
114
115       -V, --version
116              Print version info and exit.
117
118       -v, --verbose
119              Use verbose output.
120
121       --remap-path-prefix from=to
122              Remap source path prefixes in  all  output,  including  compiler
123              diagnostics,  debug  information,  macro  expansions,  etc.  The
124              from=to parameter is scanned from right to  left,  so  from  may
125              contain '=', but to may not.
126
127              This  is  useful  for normalizing build products, for example by
128              removing the current directory out of pathnames emitted into the
129              object files. The replacement is purely textual, with no consid‐
130              eration of the current system's  pathname  syntax.  For  example
131              --remap-path-prefix   foo=bar  will  match  foo/lib.rs  but  not
132              ./foo/lib.rs.
133
134       --extern NAME=PATH
135              Specify where an external rust library is located. These  should
136              match extern declarations in the crate's source code.
137
138       --sysroot PATH
139              Override the system root.
140
141       -Z FLAG
142              Set  internal debugging options.  Use -Z help to print available
143              options.
144
145       --color auto|always|never
146              Configure coloring of output:
147
148              auto   colorize, if output goes to a tty (default);
149
150              always always colorize output;
151
152              never  never colorize output.
153
154

CODEGEN OPTIONS

156       linker=/path/to/cc
157              Path to the linker utility to use when linking  libraries,  exe‐
158              cutables, and objects.
159
160       link-args='-flag1 -flag2'
161              A  space‐separated list of extra arguments to pass to the linker
162              when the linker is invoked.
163
164       lto    Perform LLVM link‐time optimizations.
165
166       target-cpu=help
167              Selects a target processor.  If the value is 'help', then a list
168              of available CPUs is printed.
169
170       target-feature='+feature1,-feature2'
171              A  comma‐separated list of features to enable or disable for the
172              target.  A preceding '+' enables a feature while a preceding '-'
173              disables  it.   Available features can be discovered through llc
174              -mcpu=help.
175
176       passes=val
177              A space‐separated list of extra LLVM passes to run.  A value  of
178              'list' will cause rustc to print all known passes and exit.  The
179              passes specified are appended at the end of the normal pass man‐
180              ager.
181
182       llvm-args='-arg1 -arg2'
183              A space‐separated list of arguments to pass through to LLVM.
184
185       save-temps
186              If  specified,  the  compiler  will  save  more  files (.bc, .o,
187              .no-opt.bc)  generated  throughout  compilation  in  the  output
188              directory.
189
190       rpath  If specified, then the rpath value for dynamic libraries will be
191              set in either dynamic library or executable outputs.
192
193       no-prepopulate-passes
194              Suppresses pre‐population of the LLVM pass manager that  is  run
195              over the module.
196
197       no-vectorize-loops
198              Suppresses  running the loop vectorization LLVM pass, regardless
199              of optimization level.
200
201       no-vectorize-slp
202              Suppresses running the LLVM SLP vectorization  pass,  regardless
203              of optimization level.
204
205       soft-float
206              Generates software floating point library calls instead of hard‐
207              ware instructions.
208
209       prefer-dynamic
210              Prefers dynamic linking to static linking.
211
212       no-integrated-as
213              Force usage of an external assembler rather  than  LLVM's  inte‐
214              grated one.
215
216       no-redzone
217              Disable the use of the redzone.
218
219       relocation-model=[pic,static,dynamic-no-pic]
220              The relocation model to use.  (Default: pic)
221
222       code-model=[small,kernel,medium,large]
223              Choose the code model to use.
224
225       metadata=val
226              Metadata to mangle symbol names with.
227
228       extra-filename=val
229              Extra data to put in each output filename.
230
231       codegen-units=n
232              Divide crate into n units to optimize in parallel.
233
234       remark=val
235              Print remarks for these optimization passes (space separated, or
236              "all").
237
238       no-stack-check
239              Disable checks for stack exhaustion (a memory‐safety hazard!).
240
241       debuginfo=val
242              Debug info emission level:
243
244              0      no debug info;
245
246              1      line‐tables only (for stacktraces and breakpoints);
247
248              2      full debug info with variable and type information.
249
250       opt-level=VAL
251              Optimize with possible levels 0–3, s (optimize for size),  or  z
252              (for minimal size)
253
254

ENVIRONMENT

256       Some  of  these  affect only test harness programs (generated via rustc
257       --test); others affect all programs which link  to  the  Rust  standard
258       library.
259
260
261       RUST_TEST_THREADS
262              The  test  framework  Rust  provides executes tests in parallel.
263              This variable sets the maximum number of threads used  for  this
264              purpose.  This  setting  is  overridden  by  the  --test-threads
265              option.
266
267
268       RUST_TEST_NOCAPTURE
269              If set to a value other than "0", a synonym for the  --nocapture
270              flag.
271
272
273       RUST_MIN_STACK
274              Sets the minimum stack size for new threads.
275
276
277       RUST_BACKTRACE
278              If  set  to  a value different than "0", produces a backtrace in
279              the output of a program which panics.
280
281

EXAMPLES

283       To build an executable from a source file with a main function:
284           $ rustc -o hello hello.rs
285
286       To build a library from a source file:
287           $ rustc --crate-type=lib hello-lib.rs
288
289       To build either with a crate (.rs) file:
290           $ rustc hello.rs
291
292       To build an executable with debug info:
293           $ rustc -g -o hello hello.rs
294
295

SEE ALSO

297       rustdoc(1)
298
299

BUGS

301       See https://github.com/rust-lang/rust/issues for issues.
302
303

AUTHOR

305       See https://github.com/rust-lang/rust/graphs/contributors or  use  `git
306       log  --all --format='%cN <%cE>' | sort -u` in the rust source distribu‐
307       tion.
308
309
311       This work is dual‐licensed under Apache 2.0 and MIT terms.   See  COPY‐
312       RIGHT file in the rust source distribution.
313
314
315
316rustc 1.43.0                      April 2020                          RUSTC(1)
Impressum