# a custom configuration file can also be specified with `--config` to the build
# system.
+# Keeps track of the last version of `x.py` used.
+# If it does not match the version that is currently running,
+# `x.py` will prompt you to update it and read the changelog.
+# See `src/bootstrap/CHANGELOG.md` for more information.
+changelog-seen = 2
+
+# =============================================================================
+# Global Settings
+# =============================================================================
+
+# Use different pre-set defaults than the global defaults.
+#
+# See `src/bootstrap/defaults` for more information.
+# Note that this has no default value (x.py uses the defaults in `config.toml.example`).
+#profile = <none>
+
# =============================================================================
# Tweaking how LLVM is compiled
# =============================================================================
[llvm]
-# Indicates whether rustc will support compilation with LLVM
-# note: rustc does not compile without LLVM at the moment
-#enabled = true
+# Whether to use Rust CI built LLVM instead of locally building it.
+#
+# Unless you're developing for a target where Rust CI doesn't build a compiler
+# toolchain or changing LLVM locally, you probably want to set this to true.
+#
+# This is false by default so that distributions don't unexpectedly download
+# LLVM from the internet.
+#
+# All tier 1 targets are currently supported; set this to `"if-supported"` if
+# you are not sure whether you're on a tier 1 target.
+#
+# We also currently only support this when building LLVM for the build triple.
+#
+# Note that many of the LLVM options are not currently supported for
+# downloading. Currently only the "assertions" option can be toggled.
+#download-ci-llvm = false
+
+# Indicates whether LLVM rebuild should be skipped when running bootstrap. If
+# this is `false` then the compiler's LLVM will be rebuilt whenever the built
+# version doesn't have the correct hash. If it is `true` then LLVM will never
+# be rebuilt. The default value is `false`.
+#skip-rebuild = false
# Indicates whether the LLVM build is a Release or Debug build
#optimize = true
# this flag will indicate that this version check should not be done.
#version-check = true
-# Link libstdc++ statically into the librustc_llvm instead of relying on a
+# Link libstdc++ statically into the rustc_llvm instead of relying on a
# dynamic version to be available.
#static-libstdcpp = false
-# Tell the LLVM build system to use Ninja instead of the platform default for
-# the generated build system. This can sometimes be faster than make, for
-# example.
-#ninja = false
+# Whether to use Ninja to build LLVM. This runs much faster than make.
+#ninja = true
# LLVM targets to build support for.
# Note: this is NOT related to Rust compilation targets. However, as Rust is
# support. You'll need to write a target specification at least, and most
# likely, teach rustc about the C ABI of the target. Get in touch with the
# Rust team and file an issue if you need assistance in porting!
-#targets = "X86;ARM;AArch64;Mips;PowerPC;SystemZ;JSBackend;MSP430;Sparc;NVPTX;Hexagon"
+#targets = "AArch64;ARM;Hexagon;MSP430;Mips;NVPTX;PowerPC;RISCV;Sparc;SystemZ;WebAssembly;X86"
# LLVM experimental targets to build support for. These targets are specified in
# the same format as above, but since these targets are experimental, they are
# not built by default and the experimental Rust compilation targets that depend
-# on them will not work unless the user opts in to building them. By default the
-# `WebAssembly` and `RISCV` targets are enabled when compiling LLVM from scratch.
-#experimental-targets = "WebAssembly;RISCV"
+# on them will not work unless the user opts in to building them.
+#experimental-targets = "AVR"
# Cap the number of parallel linker invocations when compiling LLVM.
# This can be useful when building LLVM with debug info, which significantly
#link-shared = false
# When building llvm, this configures what is being appended to the version.
-# If absent, we let the version as-is.
-#version-suffix = "-rust"
+# The default is "-rust-$version-$channel", except for dev channel where rustc
+# version number is omitted. To use LLVM version as is, provide an empty string.
+#version-suffix = "-rust-dev"
# On MSVC you can compile LLVM with clang-cl, but the test suite doesn't pass
# with clang-cl, so this is special in that it only compiles LLVM with clang-cl
# The value specified here will be passed as `-DLLVM_USE_LINKER` to CMake.
#use-linker = "lld"
+# Whether or not to specify `-DLLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN=YES`
+#allow-old-toolchain = false
+
+# Whether to include the Polly optimizer.
+#polly = false
# =============================================================================
# General build configuration options
# =============================================================================
[build]
+# The default stage to use for the `doc` subcommand
+#doc-stage = 0
+
+# The default stage to use for the `build` subcommand
+#build-stage = 1
+
+# The default stage to use for the `test` subcommand
+#test-stage = 1
+
+# The default stage to use for the `dist` subcommand
+#dist-stage = 2
+
+# The default stage to use for the `install` subcommand
+#install-stage = 2
+
+# The default stage to use for the `bench` subcommand
+#bench-stage = 2
# Build triple for the original snapshot compiler. This must be a compiler that
# nightlies are already produced for. The current platform must be able to run
# binaries of this build triple and the nightly will be used to bootstrap the
# first compiler.
-#build = "x86_64-unknown-linux-gnu" # defaults to your host platform
+#
+# Defaults to host platform
+#build = "x86_64-unknown-linux-gnu"
+
+# Which triples to produce a compiler toolchain for. Each of these triples will
+# be bootstrapped from the build triple themselves.
+#
+# Defaults to just the build triple
+#host = ["x86_64-unknown-linux-gnu"]
-# In addition to the build triple, other triples to produce full compiler
-# toolchains for. Each of these triples will be bootstrapped from the build
-# triple and then will continue to bootstrap themselves. This platform must
-# currently be able to run all of the triples provided here.
-#host = ["x86_64-unknown-linux-gnu"] # defaults to just the build triple
+# Which triples to build libraries (core/alloc/std/test/proc_macro) for. Each of
+# these triples will be bootstrapped from the build triple themselves.
+#
+# Defaults to `host`. If you set this explicitly, you likely want to add all
+# host triples to this list as well in order for those host toolchains to be
+# able to compile programs for their native target.
+#target = ["x86_64-unknown-linux-gnu"]
-# In addition to all host triples, other triples to produce the standard library
-# for. Each host triple will be used to produce a copy of the standard library
-# for each target triple.
-#target = ["x86_64-unknown-linux-gnu"] # defaults to just the build triple
+# Use this directory to store build artifacts.
+# You can use "$ROOT" to indicate the root of the git repository.
+#build-dir = "build"
# Instead of downloading the src/stage0.txt version of Cargo specified, use
# this Cargo binary instead to build all Rust code
# specified, use this rustc binary instead as the stage0 snapshot compiler.
#rustc = "/path/to/bin/rustc"
+# Instead of download the src/stage0.txt version of rustfmt specified,
+# use this rustfmt binary instead as the stage0 snapshot rustfmt.
+#rustfmt = "/path/to/bin/rustfmt"
+
# Flag to specify whether any documentation is built. If false, rustdoc and
# friends will still be compiled but they will not be used to generate any
# documentation.
#docs = true
+# Flag to specify whether CSS, JavaScript, and HTML are minified when
+# docs are generated. JSON is always minified, because it's enormous,
+# and generated in already-minified form from the beginning.
+#docs-minification = true
+
# Indicate whether the compiler should be documented in addition to the standard
# library and facade crates.
#compiler-docs = false
-# Indicate whether submodules are managed and updated automatically.
+# Indicate whether git submodules are managed and updated automatically.
#submodules = true
-# Update submodules only when the checked out commit in the submodules differs
+# Update git submodules only when the checked out commit in the submodules differs
# from what is committed in the main rustc repo.
#fast-submodules = true
# Python interpreter to use for various tasks throughout the build, notably
# rustdoc tests, the lldb python interpreter, and some dist bits and pieces.
-# Note that Python 2 is currently required.
-#python = "python2.7"
+#
+# Defaults to the Python interpreter used to execute x.py
+#python = "python"
# Force Cargo to check that Cargo.lock describes the precise dependency
# set that all the Cargo.toml files create, instead of updating it.
# Indicate whether the vendored sources are used for Rust dependencies or not
#vendor = false
-# Typically the build system will build the rust compiler twice. The second
+# Typically the build system will build the Rust compiler twice. The second
# compiler, however, will simply use its own libraries to link against. If you
# would rather to perform a full bootstrap, compiling the compiler three times,
# then you can set this option to true. You shouldn't ever need to set this
# option to true.
#full-bootstrap = false
-# Enable a build of the extended rust tool set which is not only the compiler
+# Enable a build of the extended Rust tool set which is not only the compiler
# but also tools such as Cargo. This will also produce "combined installers"
# which are used to install Rust and Cargo together. This is disabled by
-# default.
+# default. The `tools` option (immediately below) specifies which tools should
+# be built if `extended = true`.
#extended = false
-# Installs chosen set of extended tools if enables. By default builds all.
-# If chosen tool failed to build the installation fails.
+# Installs chosen set of extended tools if `extended = true`. By default builds all.
+# If chosen tool failed to build the installation fails. If `extended = false`, this
+# option is ignored.
#tools = ["cargo", "rls", "clippy", "rustfmt", "analysis", "src"]
# Verbosity level: 0 == not verbose, 1 == verbose, 2 == very verbose
# Build the sanitizer runtimes
#sanitizers = false
-# Build the profiler runtime
+# Build the profiler runtime (required when compiling with options that depend
+# on this runtime, such as `-C profile-generate` or `-Z instrument-coverage`).
#profiler = false
# Indicates whether the native libraries linked into Cargo will be statically
# tracking over time)
#print-step-timings = false
+# Print out resource usage data for each rustbuild step, as defined by the Unix
+# struct rusage. (Note that this setting is completely unstable: the data it
+# captures, what platforms it supports, the format of its associated output, and
+# this setting's very existence, are all subject to change.)
+#print-step-rusage = false
+
# =============================================================================
# General install configuration options
# =============================================================================
[rust]
# Whether or not to optimize the compiler and standard library.
-#
-# Note: the slowness of the non optimized compiler compiling itself usually
-# outweighs the time gains in not doing optimizations, therefore a
-# full bootstrap takes much more time with `optimize` set to false.
+# WARNING: Building with optimize = false is NOT SUPPORTED. Due to bootstrapping,
+# building without optimizations takes much longer than optimizing. Further, some platforms
+# fail to build without this optimization (c.f. #65352).
#optimize = true
# Indicates that the build should be configured for debugging Rust. A
#
#debug = false
+# Whether to download the stage 1 and 2 compilers from CI.
+# This is mostly useful for tools; if you have changes to `compiler/` they will be ignored.
+#
+# FIXME: currently, this also uses the downloaded compiler for stage0, but that causes unnecessary rebuilds.
+#download-rustc = false
+
# Number of codegen units to use for each compiler invocation. A value of 0
# means "the number of cores on this machine", and 1+ is passed through to the
# compiler.
-#codegen-units = 1
+#
+# Uses the rustc defaults: https://doc.rust-lang.org/rustc/codegen-options/index.html#codegen-units
+#codegen-units = if incremental { 256 } else { 16 }
# Sets the number of codegen units to build the standard library with,
# regardless of what the codegen-unit setting for the rest of the compiler is.
#codegen-units-std = 1
# Whether or not debug assertions are enabled for the compiler and standard
-# library.
-#debug-assertions = false
+# library. Debug assertions control the maximum log level used by rustc. When
+# enabled calls to `trace!` and `debug!` macros are preserved in the compiled
+# binary, otherwise they are omitted.
+#
+# Defaults to rust.debug value
+#debug-assertions = rust.debug (boolean)
-# Whether or not debuginfo is emitted
-#debuginfo = false
+# Whether or not debug assertions are enabled for the standard library.
+# Overrides the `debug-assertions` option, if defined.
+#
+# Defaults to rust.debug-assertions value
+#debug-assertions-std = rust.debug-assertions (boolean)
-# Whether or not line number debug information is emitted
-#debuginfo-lines = false
+# Whether or not to leave debug! and trace! calls in the rust binary.
+# Overrides the `debug-assertions` option, if defined.
+#
+# Defaults to rust.debug-assertions value
+#
+# If you see a message from `tracing` saying
+# `max_level_info` is enabled and means logging won't be shown,
+# set this value to `true`.
+#debug-logging = rust.debug-assertions (boolean)
+
+# Debuginfo level for most of Rust code, corresponds to the `-C debuginfo=N` option of `rustc`.
+# `0` - no debug info
+# `1` - line tables only - sufficient to generate backtraces that include line
+# information and inlined functions, set breakpoints at source code
+# locations, and step through execution in a debugger.
+# `2` - full debug info with variable and type information
+# Can be overridden for specific subsets of Rust code (rustc, std or tools).
+# Debuginfo for tests run with compiletest is not controlled by this option
+# and needs to be enabled separately with `debuginfo-level-tests`.
+#
+# Note that debuginfo-level = 2 generates several gigabytes of debuginfo
+# and will slow down the linking process significantly.
+#
+# Defaults to 1 if debug is true
+#debuginfo-level = 0
+
+# Debuginfo level for the compiler.
+#
+# Defaults to rust.debuginfo-level value
+#debuginfo-level-rustc = 0
+
+# Debuginfo level for the standard library.
+#
+# Defaults to rust.debuginfo-level value
+#debuginfo-level-std = 0
-# Whether or not to only build debuginfo for the standard library if enabled.
-# If enabled, this will not compile the compiler with debuginfo, just the
-# standard library.
-#debuginfo-only-std = false
+# Debuginfo level for the tools.
+#
+# Defaults to rust.debuginfo-level value
+#debuginfo-level-tools = 0
+
+# Debuginfo level for the test suites run with compiletest.
+# FIXME(#61117): Some tests fail when this option is enabled.
+#debuginfo-level-tests = 0
-# Enable debuginfo for the extended tools: cargo, rls, rustfmt
-# Adding debuginfo makes them several times larger.
-#debuginfo-tools = false
+# Whether to run `dsymutil` on Apple platforms to gather debug info into .dSYM
+# bundles. `dsymutil` adds time to builds for no clear benefit, and also makes
+# it more difficult for debuggers to find debug info. The compiler currently
+# defaults to running `dsymutil` to preserve its historical default, but when
+# compiling the compiler itself, we skip it by default since we know it's safe
+# to do so in that case.
+#run-dsymutil = false
# Whether or not `panic!`s generate backtraces (RUST_BACKTRACE)
#backtrace = true
#incremental = false
# Build a multi-threaded rustc
+# FIXME(#75760): Some UI tests fail when this option is enabled.
#parallel-compiler = false
# The default linker that will be hard-coded into the generated compiler for
# nightly features
#channel = "dev"
+# A descriptive string to be appended to `rustc --version` output, which is
+# also used in places like debuginfo `DW_AT_producer`. This may be useful for
+# supplementary build information, like distro-specific package versions.
+#description = ""
+
+# The root location of the musl installation directory.
+#musl-root = "..."
+
# By default the `rustc` executable is built with `-Wl,-rpath` flags on Unix
# platforms to ensure that the compiler is usable by default from the build
# directory (as it links to a number of dynamic libraries). This may not be
# desired in distributions, for example.
#rpath = true
-# Emits extraneous output from tests to ensure that failures of the test
-# harness are debuggable just from logfiles.
+# Prints each test name as it is executed, to help debug issues in the test harness itself.
#verbose-tests = false
-# Flag indicating whether tests are compiled with optimizations (the -O flag) or
-# with debuginfo (the -g flag)
+# Flag indicating whether tests are compiled with optimizations (the -O flag).
#optimize-tests = true
-#debuginfo-tests = true
# Flag indicating whether codegen tests will be run or not. If you get an error
# saying that the FileCheck executable is missing, you may want to disable this.
# When creating source tarballs whether or not to create a source tarball.
#dist-src = false
-# Whether to also run the Miri tests suite when running tests.
-# As a side-effect also generates MIR for all libraries.
-#test-miri = false
-
# After building or testing extended tools (e.g. clippy and rustfmt), append the
# result (broken, compiling, testing) into this JSON file.
#save-toolstates = "/path/to/toolstates.json"
# This is an array of the codegen backends that will be compiled for the rustc
# that's being compiled. The default is to only build the LLVM codegen backend,
-# but you can also optionally enable the "emscripten" backend for asm.js or
-# make this an empty array (but that probably won't get too far in the
-# bootstrap)
+# and currently the only standard options supported are `"llvm"` and `"cranelift"`.
#codegen-backends = ["llvm"]
-# This is the name of the directory in which codegen backends will get installed
-#codegen-backends-dir = "codegen-backends"
-
-# Flag indicating whether `libstd` calls an imported function to handle basic IO
-# when targeting WebAssembly. Enable this to debug tests for the `wasm32-unknown-unknown`
-# target, as without this option the test output will not be captured.
-#wasm-syscall = false
-
# Indicates whether LLD will be compiled and made available in the sysroot for
# rustc to execute.
#lld = false
+# Indicates whether LLD will be used to link Rust crates during bootstrap on
+# supported platforms. The LLD from the bootstrap distribution will be used
+# and not the LLD compiled during the bootstrap.
+#
+# LLD will not be used if we're cross linking.
+#
+# Explicitly setting the linker for a target will override this option when targeting MSVC.
+#use-lld = false
+
# Indicates whether some LLVM tools, like llvm-objdump, will be made available in the
# sysroot.
#llvm-tools = false
-# Indicates whether LLDB will be made available in the sysroot.
-# This is only built if LLVM is also being built.
-#lldb = false
-
# Whether to deny warnings in crates
#deny-warnings = true
# Whether to verify generated LLVM IR
#verify-llvm-ir = false
-# Map all debuginfo paths for libstd and crates to `/rust/$sha/$crate/...`,
-# generally only set for releases
+# Compile the compiler with a non-default ThinLTO import limit. This import
+# limit controls the maximum size of functions imported by ThinLTO. Decreasing
+# will make code compile faster at the expense of lower runtime performance.
+# If `incremental` is set to true above, the import limit will default to 10
+# instead of LLVM's default of 100.
+#thin-lto-import-instr-limit = 100
+
+# Map debuginfo paths to `/rust/$sha/...`, generally only set for releases
#remap-debuginfo = false
# Link the compiler against `jemalloc`, where on Linux and OSX it should
# development of NLL
#test-compare-mode = false
+# Use LLVM libunwind as the implementation for Rust's unwinder.
+# Accepted values are 'in-tree' (formerly true), 'system' or 'no' (formerly false).
+#llvm-libunwind = 'no'
+
+# Enable Windows Control Flow Guard checks in the standard library.
+# This only applies from stage 1 onwards, and only for Windows targets.
+#control-flow-guard = false
+
+# Enable symbol-mangling-version v0. This can be helpful when profiling rustc,
+# as generics will be preserved in symbols (rather than erased into opaque T).
+#new-symbol-mangling = false
+
# =============================================================================
# Options for specific targets
#
# Linker to be used to link Rust code. Note that the
# default value is platform specific, and if not specified it may also depend on
# what platform is crossing to what platform.
+# Setting this will override the `use-lld` option for Rust code when targeting MSVC.
#linker = "cc"
# Path to the `llvm-config` binary of the installation of a custom LLVM to link
# build native code.
#android-ndk = "/path/to/ndk"
+# Build the sanitizer runtimes for this target.
+# This option will override the same option under [build] section.
+#sanitizers = false
+
+# Build the profiler runtime for this target(required when compiling with options that depend
+# on this runtime, such as `-C profile-generate` or `-Z instrument-coverage`).
+# This option will override the same option under [build] section.
+#profiler = false
+
# Force static or dynamic linkage of the standard library for this target. If
# this target is a host for rustc, this will also affect the linkage of the
# compiler itself. This is useful for building rustc on targets that normally
# only use static libraries. If unset, the target's default linkage is used.
#crt-static = false
-# The root location of the MUSL installation directory. The library directory
+# The root location of the musl installation directory. The library directory
# will also need to contain libunwind.a for an unwinding implementation. Note
-# that this option only makes sense for MUSL targets that produce statically
+# that this option only makes sense for musl targets that produce statically
# linked binaries
#musl-root = "..."
+# The full path to the musl libdir.
+#musl-libdir = musl-root/lib
+
+# The root location of the `wasm32-wasi` sysroot. Only used for the
+# `wasm32-wasi` target. If you are building wasm32-wasi target, make sure to
+# create a `[target.wasm32-wasi]` section and move this field there.
+#wasi-root = "..."
+
# Used in testing for configuring where the QEMU images are located, you
# probably don't want to use this.
#qemu-rootfs = "..."
# Whether to allow failures when building tools
#missing-tools = false
+
+# List of compression formats to use when generating dist tarballs. The list of
+# formats is provided to rust-installer, which must support all of them.
+#compression-formats = ["gz", "xz"]