Provided by: rustc-1.68_1.68.2+dfsg0ubuntu1-0ubuntu4_amd64 bug

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.