NAME

       rustc - The Rust compiler

SYNOPSIS

       rustc [OPTIONS] INPUT

DESCRIPTION

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

OPTIONS

       -h, --help
              Display the help message.

       --cfg SPEC
              Configure the compilation environment.

       -L [KIND=]PATH
              Add a directory to the library search path.  The optional KIND can be one of:

              dependency
                     only lookup transitive dependencies here

              crate  only lookup local `extern crate` directives here

              native only lookup native libraries here

              framework
                     only look for OSX frameworks here

              all    look for anything here (the default)

       -l [KIND=]NAME
              Link  the  generated  crate(s)  to  the  specified  library NAME.  The optional KIND can be one of
              static, dylib, or framework.  If omitted, dylib is assumed.

       --crate-type [bin|lib|rlib|dylib|cdylib|staticlib|proc-macro]
              Comma separated list of types of crates for the compiler to emit.

       --crate-name NAME
              Specify the name of the crate being built.

       --emit [asm|llvm-bc|llvm-ir|obj|metadata|link|dep-info|mir][=PATH]
              Configure the output that rustc will produce. Each emission may also  have  an  optional  explicit
              output  PATH  specified  for that particular emission kind. This path takes precedence over the -o
              option.

       --print         [crate-name|file-names|sysroot|target-libdir|cfg|target-list|target-cpus|target-features|
       relocation-models|code-models|tls-models|target-spec-json|native-static-libs|stack-protector-strategies|
       link-args]
              Comma separated list of compiler information to print on stdout.

       -g     Equivalent to -C debuginfo=2.

       -O     Equivalent to -C opt-level=2.

       -o FILENAME
              Write output to FILENAME. Ignored if multiple --emit outputs are specified  which  don't  have  an
              explicit path otherwise.

       --out-dir DIR
              Write  output  to  compiler‐chosen  filename  in DIR. Ignored if -o is specified.  Defaults to the
              current directory.

       --explain OPT
              Provide a detailed explanation of an error message.

       --test Build a test harness.

       --target TARGET
              Target triple for which the code is compiled. This option defaults to the  host’s  target  triple.
              The target triple has the general format <arch><sub>-<vendor>-<sys>-<abi>, where:

              <arch> x86, arm, thumb, mips, etc.

              <sub>  for example on ARM: v5, v6m, v7a, v7m, etc.

              <vendor>
                     pc, apple, nvidia, ibm, etc.

              <sys>  none, linux, win32, darwin, cuda, etc.

              <abi>  eabi, gnu, android, macho, elf, etc.

       -W help
              Print 'lint' options and default settings.

       -W OPT, --warn OPT
              Set lint warnings.

       -A OPT, --allow OPT
              Set lint allowed.

       -D OPT, --deny OPT
              Set lint denied.

       -F OPT, --forbid OPT
              Set lint forbidden.

       -C FLAG[=VAL], --codegen FLAG[=VAL]
              Set  a  codegen‐related  flag  to the value specified.  Use -C help to print available flags.  See
              CODEGEN OPTIONS below.

       -V, --version
              Print version info and exit.

       -v, --verbose
              Use verbose output.

       --remap-path-prefix from=to
              Remap source path prefixes in all output, including compiler diagnostics, debug information, macro
              expansions, etc. The from=to parameter is scanned from right to left, so from may contain '=', but
              to may not.

              This is useful for normalizing build products, for example by removing the current  directory  out
              of  pathnames  emitted  into  the  object  files.  The  replacement  is  purely  textual,  with no
              consideration of the current system's pathname syntax.  For  example  --remap-path-prefix  foo=bar
              will match foo/lib.rs but not ./foo/lib.rs.

       --extern NAME=PATH
              Specify  where  an external rust library is located. These should match extern declarations in the
              crate's source code.

       --sysroot PATH
              Override the system root.

       -Z FLAG
              Set unstable / perma-unstable options.  Use -Z help to print available options.

       --color auto|always|never
              Configure coloring of output:

              auto   colorize, if output goes to a tty (default);

              always always colorize output;

              never  never colorize output.

CODEGEN OPTIONS

       linker=/path/to/cc
              Path to the linker utility to use when linking libraries, executables, and objects.

       link-args='-flag1 -flag2'
              A space‐separated list of extra arguments to pass to the linker when the linker is invoked.

       lto    Perform LLVM link‐time optimizations.

       target-cpu=help
              Selects a target processor.  If the value is 'help', then a list of available CPUs is printed.

       target-feature='+feature1,-feature2'
              A comma‐separated list of features to enable or disable for the target.  A preceding '+' enables a
              feature  while  a  preceding  '-'  disables  it.  Available features can be discovered through llc
              -mcpu=help.

       passes=val
              A space‐separated list of extra LLVM passes to run.  A value of 'list' will cause rustc  to  print
              all  known  passes  and  exit.   The  passes  specified are appended at the end of the normal pass
              manager.

       llvm-args='-arg1 -arg2'
              A space‐separated list of arguments to pass through to LLVM.

       save-temps
              If specified, the compiler will  save  more  files  (.bc,  .o,  .no-opt.bc)  generated  throughout
              compilation in the output directory.

       rpath  If  specified, then the rpath value for dynamic libraries will be set in either dynamic library or
              executable outputs.

       no-prepopulate-passes
              Suppresses pre‐population of the LLVM pass manager that is run over the module.

       no-vectorize-loops
              Suppresses running the loop vectorization LLVM pass, regardless of optimization level.

       no-vectorize-slp
              Suppresses running the LLVM SLP vectorization pass, regardless of optimization level.

       soft-float
              Generates software floating point library calls instead of hardware instructions.

       prefer-dynamic
              Prefers dynamic linking to static linking.

       no-integrated-as
              Force usage of an external assembler rather than LLVM's integrated one.

       no-redzone
              Disable the use of the redzone.

       relocation-model=[pic,static,dynamic-no-pic]
              The relocation model to use.  (Default: pic)

       code-model=[small,kernel,medium,large]
              Choose the code model to use.

       metadata=val
              Metadata to mangle symbol names with.

       extra-filename=val
              Extra data to put in each output filename.

       codegen-units=n
              Divide crate into n units to optimize in parallel.

       remark=val
              Print remarks for these optimization passes (space separated, or "all").

       no-stack-check
              Disable checks for stack exhaustion (a memory‐safety hazard!).

       debuginfo=val
              Debug info emission level:

              0      no debug info;

              1      line‐tables only (for stacktraces and breakpoints);

              2      full debug info with variable and type information.

       opt-level=VAL
              Optimize with possible levels 0–3, s (optimize for size), or z (for minimal size)

ENVIRONMENT

       Some of these affect only test harness programs (generated via rustc --test); others affect all  programs
       which link to the Rust standard library.

       RUST_TEST_THREADS
              The test framework Rust provides executes tests in parallel. This variable sets the maximum number
              of threads used for this purpose. This setting is overridden by the --test-threads option.

       RUST_TEST_NOCAPTURE
              If set to a value other than "0", a synonym for the --nocapture flag.

       RUST_MIN_STACK
              Sets the minimum stack size for new threads.

       RUST_BACKTRACE
              If set to a value different than "0", produces a backtrace  in  the  output  of  a  program  which
              panics.

EXAMPLES

       To build an executable from a source file with a main function:
           $ rustc -o hello hello.rs

       To build a library from a source file:
           $ rustc --crate-type=lib hello-lib.rs

       To build either with a crate (.rs) file:
           $ rustc hello.rs

       To build an executable with debug info:
           $ rustc -g -o hello hello.rs

SEE ALSO

       rustdoc(1)

BUGS

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

AUTHOR

       See  https://github.com/rust-lang/rust/graphs/contributors  or  use `git log --all --format='%cN <%cE>' |
       sort -u` in the rust source distribution.

COPYRIGHT

       This work is dual‐licensed under Apache 2.0 and MIT  terms.   See  COPYRIGHT  file  in  the  rust  source
       distribution.