bootstrap/core/
sanity.rs

1//! Sanity checking performed by bootstrap before actually executing anything.
2//!
3//! This module contains the implementation of ensuring that the build
4//! environment looks reasonable before progressing. This will verify that
5//! various programs like git and python exist, along with ensuring that all C
6//! compilers for cross-compiling are found.
7//!
8//! In theory if we get past this phase it's a bug if a build fails, but in
9//! practice that's likely not true!
10
11use std::collections::{HashMap, HashSet};
12use std::ffi::{OsStr, OsString};
13use std::path::PathBuf;
14use std::{env, fs};
15
16#[cfg(not(test))]
17use crate::builder::Builder;
18use crate::builder::Kind;
19#[cfg(not(test))]
20use crate::core::build_steps::tool;
21use crate::core::config::{CompilerBuiltins, Target};
22use crate::utils::exec::command;
23use crate::{Build, Subcommand};
24
25pub struct Finder {
26    cache: HashMap<OsString, Option<PathBuf>>,
27    path: OsString,
28}
29
30// During sanity checks, we search for target names to determine if they exist in the compiler's built-in
31// target list (`rustc --print target-list`). While a target name may be present in the stage2 compiler,
32// it might not yet be included in stage0. In such cases, we handle the targets missing from stage0 in this list.
33//
34// Targets can be removed from this list once they are present in the stage0 compiler (usually by updating the beta compiler of the bootstrap).
35const STAGE0_MISSING_TARGETS: &[&str] = &[
36    "armv7a-vex-v5",
37    "riscv64a23-unknown-linux-gnu",
38    // just a dummy comment so the list doesn't get onelined
39    "aarch64_be-unknown-hermit",
40    "aarch64_be-unknown-none-softfloat",
41];
42
43/// Minimum version threshold for libstdc++ required when using prebuilt LLVM
44/// from CI (with`llvm.download-ci-llvm` option).
45#[cfg(not(test))]
46const LIBSTDCXX_MIN_VERSION_THRESHOLD: usize = 8;
47
48impl Finder {
49    pub fn new() -> Self {
50        Self { cache: HashMap::new(), path: env::var_os("PATH").unwrap_or_default() }
51    }
52
53    pub fn maybe_have<S: Into<OsString>>(&mut self, cmd: S) -> Option<PathBuf> {
54        let cmd: OsString = cmd.into();
55        let path = &self.path;
56        self.cache
57            .entry(cmd.clone())
58            .or_insert_with(|| {
59                for path in env::split_paths(path) {
60                    let target = path.join(&cmd);
61                    let mut cmd_exe = cmd.clone();
62                    cmd_exe.push(".exe");
63
64                    if target.is_file()                   // some/path/git
65                    || path.join(&cmd_exe).exists()   // some/path/git.exe
66                    || target.join(&cmd_exe).exists()
67                    // some/path/git/git.exe
68                    {
69                        return Some(target);
70                    }
71                }
72                None
73            })
74            .clone()
75    }
76
77    pub fn must_have<S: AsRef<OsStr>>(&mut self, cmd: S) -> PathBuf {
78        self.maybe_have(&cmd).unwrap_or_else(|| {
79            panic!("\n\ncouldn't find required command: {:?}\n\n", cmd.as_ref());
80        })
81    }
82}
83
84pub fn check(build: &mut Build) {
85    let mut skip_target_sanity =
86        env::var_os("BOOTSTRAP_SKIP_TARGET_SANITY").is_some_and(|s| s == "1" || s == "true");
87
88    skip_target_sanity |= build.config.cmd.kind() == Kind::Check;
89
90    // Skip target sanity checks when we are doing anything with mir-opt tests or Miri
91    let skipped_paths = [OsStr::new("mir-opt"), OsStr::new("miri")];
92    skip_target_sanity |= build.config.paths.iter().any(|path| {
93        path.components().any(|component| skipped_paths.contains(&component.as_os_str()))
94    });
95
96    let path = env::var_os("PATH").unwrap_or_default();
97    // On Windows, quotes are invalid characters for filename paths, and if
98    // one is present as part of the PATH then that can lead to the system
99    // being unable to identify the files properly. See
100    // https://github.com/rust-lang/rust/issues/34959 for more details.
101    if cfg!(windows) && path.to_string_lossy().contains('\"') {
102        panic!("PATH contains invalid character '\"'");
103    }
104
105    let mut cmd_finder = Finder::new();
106    // If we've got a git directory we're gonna need git to update
107    // submodules and learn about various other aspects.
108    if build.rust_info().is_managed_git_subrepository() {
109        cmd_finder.must_have("git");
110    }
111
112    // Ensure that a compatible version of libstdc++ is available on the system when using `llvm.download-ci-llvm`.
113    #[cfg(not(test))]
114    if !build.config.dry_run() && !build.host_target.is_msvc() && build.config.llvm_from_ci {
115        let builder = Builder::new(build);
116        let libcxx_version = builder.ensure(tool::LibcxxVersionTool { target: build.host_target });
117
118        match libcxx_version {
119            tool::LibcxxVersion::Gnu(version) => {
120                if LIBSTDCXX_MIN_VERSION_THRESHOLD > version {
121                    eprintln!(
122                        "\nYour system's libstdc++ version is too old for the `llvm.download-ci-llvm` option."
123                    );
124                    eprintln!("Current version detected: '{version}'");
125                    eprintln!("Minimum required version: '{LIBSTDCXX_MIN_VERSION_THRESHOLD}'");
126                    eprintln!(
127                        "Consider upgrading libstdc++ or disabling the `llvm.download-ci-llvm` option."
128                    );
129                    eprintln!(
130                        "If you choose to upgrade libstdc++, run `x clean` or delete `build/host/libcxx-version` manually after the upgrade."
131                    );
132                }
133            }
134            tool::LibcxxVersion::Llvm(_) => {
135                // FIXME: Handle libc++ version check.
136            }
137        }
138    }
139
140    // We need cmake, but only if we're actually building LLVM or sanitizers.
141    let building_llvm = !build.config.llvm_from_ci
142        && build.hosts.iter().any(|host| {
143            build.config.llvm_enabled(*host)
144                && build
145                    .config
146                    .target_config
147                    .get(host)
148                    .map(|config| config.llvm_config.is_none())
149                    .unwrap_or(true)
150        });
151
152    let need_cmake = building_llvm || build.config.any_sanitizers_to_build();
153    if need_cmake && cmd_finder.maybe_have("cmake").is_none() {
154        eprintln!(
155            "
156Couldn't find required command: cmake
157
158You should install cmake, or set `download-ci-llvm = true` in the
159`[llvm]` section of `bootstrap.toml` to download LLVM rather
160than building it.
161"
162        );
163        crate::exit!(1);
164    }
165
166    build.config.python = build
167        .config
168        .python
169        .take()
170        .map(|p| cmd_finder.must_have(p))
171        .or_else(|| env::var_os("BOOTSTRAP_PYTHON").map(PathBuf::from)) // set by bootstrap.py
172        .or_else(|| cmd_finder.maybe_have("python"))
173        .or_else(|| cmd_finder.maybe_have("python3"))
174        .or_else(|| cmd_finder.maybe_have("python2"));
175
176    build.config.nodejs = build
177        .config
178        .nodejs
179        .take()
180        .map(|p| cmd_finder.must_have(p))
181        .or_else(|| cmd_finder.maybe_have("node"))
182        .or_else(|| cmd_finder.maybe_have("nodejs"));
183
184    build.config.npm = build
185        .config
186        .npm
187        .take()
188        .map(|p| cmd_finder.must_have(p))
189        .or_else(|| cmd_finder.maybe_have("npm"));
190
191    build.config.gdb = build
192        .config
193        .gdb
194        .take()
195        .map(|p| cmd_finder.must_have(p))
196        .or_else(|| cmd_finder.maybe_have("gdb"));
197
198    build.config.reuse = build
199        .config
200        .reuse
201        .take()
202        .map(|p| cmd_finder.must_have(p))
203        .or_else(|| cmd_finder.maybe_have("reuse"));
204
205    let stage0_supported_target_list: HashSet<String> = command(&build.config.initial_rustc)
206        .args(["--print", "target-list"])
207        .run_in_dry_run()
208        .run_capture_stdout(&build)
209        .stdout()
210        .lines()
211        .map(|s| s.to_string())
212        .collect();
213
214    // Compiler tools like `cc` and `ar` are not configured for cross-targets on certain subcommands
215    // because they are not needed.
216    //
217    // See `cc_detect::find` for more details.
218    let skip_tools_checks = build.config.dry_run()
219        || matches!(
220            build.config.cmd,
221            Subcommand::Clean { .. }
222                | Subcommand::Check { .. }
223                | Subcommand::Format { .. }
224                | Subcommand::Setup { .. }
225        );
226
227    // We're gonna build some custom C code here and there, host triples
228    // also build some C++ shims for LLVM so we need a C++ compiler.
229    for target in &build.targets {
230        // On emscripten we don't actually need the C compiler to just
231        // build the target artifacts, only for testing. For the sake
232        // of easier bot configuration, just skip detection.
233        if target.contains("emscripten") {
234            continue;
235        }
236
237        // We don't use a C compiler on wasm32
238        if target.contains("wasm32") {
239            continue;
240        }
241
242        // skip check for cross-targets
243        if skip_target_sanity && target != &build.host_target {
244            continue;
245        }
246
247        // Ignore fake targets that are only used for unit tests in bootstrap.
248        if cfg!(not(test)) && !skip_target_sanity && !build.local_rebuild {
249            let mut has_target = false;
250            let target_str = target.to_string();
251
252            let missing_targets_hashset: HashSet<_> =
253                STAGE0_MISSING_TARGETS.iter().map(|t| t.to_string()).collect();
254            let duplicated_targets: Vec<_> =
255                stage0_supported_target_list.intersection(&missing_targets_hashset).collect();
256
257            if !duplicated_targets.is_empty() {
258                println!(
259                    "Following targets supported from the stage0 compiler, please remove them from STAGE0_MISSING_TARGETS list."
260                );
261                for duplicated_target in duplicated_targets {
262                    println!("  {duplicated_target}");
263                }
264                std::process::exit(1);
265            }
266
267            // Check if it's a built-in target.
268            has_target |= stage0_supported_target_list.contains(&target_str);
269            has_target |= STAGE0_MISSING_TARGETS.contains(&target_str.as_str());
270
271            if !has_target {
272                // This might also be a custom target, so check the target file that could have been specified by the user.
273                if target.filepath().is_some_and(|p| p.exists()) {
274                    has_target = true;
275                } else if let Some(custom_target_path) = env::var_os("RUST_TARGET_PATH") {
276                    let mut target_filename = OsString::from(&target_str);
277                    // Target filename ends with `.json`.
278                    target_filename.push(".json");
279
280                    // Recursively traverse through nested directories.
281                    let walker = walkdir::WalkDir::new(custom_target_path).into_iter();
282                    for entry in walker.filter_map(|e| e.ok()) {
283                        has_target |= entry.file_name() == target_filename;
284                    }
285                }
286            }
287
288            if !has_target {
289                panic!(
290                    "No such target exists in the target list,\n\
291                     make sure to correctly specify the location \
292                     of the JSON specification file \
293                     for custom targets!\n\
294                     Use BOOTSTRAP_SKIP_TARGET_SANITY=1 to \
295                     bypass this check."
296                );
297            }
298        }
299
300        if !skip_tools_checks {
301            cmd_finder.must_have(build.cc(*target));
302            if let Some(ar) = build.ar(*target) {
303                cmd_finder.must_have(ar);
304            }
305        }
306    }
307
308    if !skip_tools_checks {
309        for host in &build.hosts {
310            cmd_finder.must_have(build.cxx(*host).unwrap());
311
312            if build.config.llvm_enabled(*host) {
313                // Externally configured LLVM requires FileCheck to exist
314                let filecheck = build.llvm_filecheck(build.host_target);
315                if !filecheck.starts_with(&build.out)
316                    && !filecheck.exists()
317                    && build.config.codegen_tests
318                {
319                    panic!("FileCheck executable {filecheck:?} does not exist");
320                }
321            }
322        }
323    }
324
325    for target in &build.targets {
326        build
327            .config
328            .target_config
329            .entry(*target)
330            .or_insert_with(|| Target::from_triple(&target.triple));
331
332        // compiler-rt c fallbacks for wasm cannot be built with gcc
333        if target.contains("wasm")
334            && (*build.config.optimized_compiler_builtins(*target)
335                != CompilerBuiltins::BuildRustOnly
336                || build.config.rust_std_features.contains("compiler-builtins-c"))
337        {
338            let cc_tool = build.cc_tool(*target);
339            if !cc_tool.is_like_clang() && !cc_tool.path().ends_with("emcc") {
340                // emcc works as well
341                panic!(
342                    "Clang is required to build C code for Wasm targets, got `{}` instead\n\
343                    this is because compiler-builtins is configured to build C source. Either \
344                    ensure Clang is used, or adjust this configuration.",
345                    cc_tool.path().display()
346                );
347            }
348        }
349
350        if (target.contains("-none-") || target.contains("nvptx"))
351            && build.no_std(*target) == Some(false)
352        {
353            panic!("All the *-none-* and nvptx* targets are no-std targets")
354        }
355
356        // skip check for cross-targets
357        if skip_target_sanity && target != &build.host_target {
358            continue;
359        }
360
361        // Make sure musl-root is valid.
362        if target.contains("musl") && !target.contains("unikraft") {
363            match build.musl_libdir(*target) {
364                Some(libdir) => {
365                    if fs::metadata(libdir.join("libc.a")).is_err() {
366                        panic!("couldn't find libc.a in musl libdir: {}", libdir.display());
367                    }
368                }
369                None => panic!(
370                    "when targeting MUSL either the rust.musl-root \
371                            option or the target.$TARGET.musl-root option must \
372                            be specified in bootstrap.toml"
373                ),
374            }
375        }
376
377        if need_cmake && target.is_msvc() {
378            // There are three builds of cmake on windows: MSVC, MinGW, and
379            // Cygwin. The Cygwin build does not have generators for Visual
380            // Studio, so detect that here and error.
381            let out =
382                command("cmake").arg("--help").run_in_dry_run().run_capture_stdout(&build).stdout();
383            if !out.contains("Visual Studio") {
384                panic!(
385                    "
386cmake does not support Visual Studio generators.
387
388This is likely due to it being an msys/cygwin build of cmake,
389rather than the required windows version, built using MinGW
390or Visual Studio.
391
392If you are building under msys2 try installing the mingw-w64-x86_64-cmake
393package instead of cmake:
394
395$ pacman -R cmake && pacman -S mingw-w64-x86_64-cmake
396"
397                );
398            }
399        }
400
401        // For testing `wasm32-wasip2`-and-beyond it's required to have
402        // `wasm-component-ld`. This is enabled by default via `tool_enabled`
403        // but if it's disabled then double-check it's present on the system.
404        if target.contains("wasip")
405            && !target.contains("wasip1")
406            && !build.tool_enabled("wasm-component-ld")
407        {
408            cmd_finder.must_have("wasm-component-ld");
409        }
410    }
411
412    if let Some(ref s) = build.config.ccache {
413        cmd_finder.must_have(s);
414    }
415}