Rollup merge of #154616 - erickt:quiet, r=jieyouxu

Add `--quiet` flag to x.py and bootstrap to suppress output

This adds a `--quiet` flag to x.py and bootstrap to suppress some of the output when compiling Rust. It conflicts with `--verbose`, matching the behavior of `cargo` which does not allow `--verbose` and `--quiet`.

It works by passing quiet flags down to the underlying cargo, or LLVM build processes. Note that for LLVM, we only can suppress logs when we explicitly configure it with ninja. Otherwise we won't know what flag to pass along to whichever build system cmake decides to use.

This can be helpful with AI workloads in the Rust codebase to help shrink down the output to reduce token usage, which can help prevent context pollution and lower costs.

This patch was partially generated with Gemini, but I've reviewed the changes it made.

Author: jhpratt

src/bootstrap/bootstrap.py

@@ -49,7 +49,7 @@ def eprint(*args, **kwargs):
     print(*args, **kwargs)
 
 
-def get(base, url, path, checksums, verbose=False):
+def get(base, url, path, checksums, verbose=0):
     with tempfile.NamedTemporaryFile(delete=False) as temp_file:
         temp_path = temp_file.name
 
@@ -66,11 +66,11 @@ def get(base, url, path, checksums, verbose=False):
         sha256 = checksums[url]
         if os.path.exists(path):
             if verify(path, sha256, False):
-                if verbose:
+                if verbose > 0:
                     eprint("using already-download file", path)
                 return
             else:
-                if verbose:
+                if verbose > 0:
                     eprint(
                         "ignoring already-download file",
                         path,
@@ -80,12 +80,12 @@ def get(base, url, path, checksums, verbose=False):
         download(temp_path, "{}/{}".format(base, url), True, verbose)
         if not verify(temp_path, sha256, verbose):
             raise RuntimeError("failed verification")
-        if verbose:
+        if verbose > 0:
             eprint("moving {} to {}".format(temp_path, path))
         shutil.move(temp_path, path)
     finally:
         if os.path.isfile(temp_path):
-            if verbose:
+            if verbose > 0:
                 eprint("removing", temp_path)
             os.unlink(temp_path)
 
@@ -113,11 +113,11 @@ def _download(path, url, probably_big, verbose, exception):
     # If an error occurs:
     #  - If we are on win32 fallback to powershell
     #  - Otherwise raise the error if appropriate
-    if probably_big or verbose:
+    if probably_big or verbose > 0:
         eprint("downloading {}".format(url))
 
     try:
-        if (probably_big or verbose) and "GITHUB_ACTIONS" not in os.environ:
+        if (probably_big or verbose > 0) and "GITHUB_ACTIONS" not in os.environ:
             option = "--progress-bar"
         else:
             option = "--silent"
@@ -180,7 +180,7 @@ def _download(path, url, probably_big, verbose, exception):
 
 def verify(path, expected, verbose):
     """Check if the sha256 sum of the given path is valid"""
-    if verbose:
+    if verbose > 0:
         eprint("verifying", path)
     with open(path, "rb") as source:
         found = hashlib.sha256(source.read()).hexdigest()
@@ -194,7 +194,7 @@ def verify(path, expected, verbose):
     return verified
 
 
-def unpack(tarball, tarball_suffix, dst, verbose=False, match=None):
+def unpack(tarball, tarball_suffix, dst, verbose=0, match=None):
     """Unpack the given tarball file"""
     eprint("extracting", tarball)
     fname = os.path.basename(tarball).replace(tarball_suffix, "")
@@ -208,7 +208,7 @@ def unpack(tarball, tarball_suffix, dst, verbose=False, match=None):
             name = name[len(match) + 1 :]
 
             dst_path = os.path.join(dst, name)
-            if verbose:
+            if verbose > 0:
                 eprint("  extracting", member)
             tar.extract(member, dst)
             src_path = os.path.join(dst, member)
@@ -218,9 +218,9 @@ def unpack(tarball, tarball_suffix, dst, verbose=False, match=None):
     shutil.rmtree(os.path.join(dst, fname))
 
 
-def run(args, verbose=False, exception=False, is_bootstrap=False, **kwargs):
+def run(args, verbose=0, exception=False, is_bootstrap=False, **kwargs):
     """Run a child program in a new process"""
-    if verbose:
+    if verbose > 0:
         eprint("running: " + " ".join(args))
     sys.stdout.flush()
     # Ensure that the .exe is used on Windows just in case a Linux ELF has been
@@ -233,7 +233,7 @@ def run(args, verbose=False, exception=False, is_bootstrap=False, **kwargs):
     code = ret.wait()
     if code != 0:
         err = "failed to run: " + " ".join(args)
-        if verbose or exception:
+        if verbose > 0 or exception:
             raise RuntimeError(err)
         # For most failures, we definitely do want to print this error, or the user will have no
         # idea what went wrong. But when we've successfully built bootstrap and it failed, it will
@@ -293,13 +293,13 @@ def default_build_triple(verbose):
             version = version.decode(default_encoding)
             host = next(x for x in version.split("\n") if x.startswith("host: "))
             triple = host.split("host: ")[1]
-            if verbose:
+            if verbose > 0:
                 eprint(
                     "detected default triple {} from pre-installed rustc".format(triple)
                 )
             return triple
         except Exception as e:
-            if verbose:
+            if verbose > 0:
                 eprint("pre-installed rustc not detected: {}".format(e))
                 eprint("falling back to auto-detect")
 
@@ -699,7 +699,7 @@ def download_toolchain(self):
             # Unpack the tarballs in parallel.
             # In Python 2.7, Pool cannot be used as a context manager.
             pool_size = min(len(tarballs_download_info), get_cpus())
-            if self.verbose:
+            if self.verbose > 0:
                 print(
                     "Choosing a pool size of",
                     pool_size,
@@ -1126,6 +1126,8 @@ def build_bootstrap_cmd(self, env):
         ]
         # verbose cargo output is very noisy, so only enable it with -vv
         args.extend("--verbose" for _ in range(self.verbose - 1))
+        if self.verbose < 0:
+            args.append("--quiet")
 
         target_features = []
         if self.get_toml("crt-static", build_section) == "true":
@@ -1275,7 +1277,12 @@ def parse_args(args):
     parser.add_argument(
         "--warnings", choices=["deny", "warn", "default"], default="default"
     )
-    parser.add_argument("-v", "--verbose", action="count", default=0)
+    group = parser.add_mutually_exclusive_group()
+    group.add_argument("-v", "--verbose", action="count", default=0)
+    # Note that we're storing the `--quiet` value in `verbose`. That way we don't need to thread
+    # `self.quiet` throughout the code. That could be error prone, which could let some output
+    # through that should have been suppressed.
+    group.add_argument("-q", "--quiet", action="store_const", const=-1, dest="verbose")
 
     return parser.parse_known_args(args)[0]
 

src/bootstrap/src/core/build_steps/llvm.rs

@@ -651,6 +651,18 @@ fn configure_cmake(
     // LLVM and LLD builds can produce a lot of those and hit CI limits on log size.
     cfg.define("CMAKE_INSTALL_MESSAGE", "LAZY");
 
+    if builder.config.quiet {
+        // Only log errors and warnings from `cmake`.
+        cfg.define("CMAKE_MESSAGE_LOG_LEVEL", "WARNING");
+
+        // If we're configuring llvm to build with `ninja`, we can suppress output from it with
+        // `--quiet`. Otherwise don't add anything since we don't know which build system is going
+        // to use.
+        if builder.ninja() {
+            cfg.build_arg("--quiet");
+        }
+    }
+
     // Do not allow the user's value of DESTDIR to influence where
     // LLVM will install itself. LLVM must always be installed in our
     // own build directories.

src/bootstrap/src/core/builder/cargo.rs

@@ -509,6 +509,11 @@ impl Builder<'_> {
             }
         };
 
+        // Optionally suppress cargo output.
+        if self.config.quiet {
+            cargo.arg("--quiet");
+        }
+
         // Run cargo from the source root so it can find .cargo/config.
         // This matters when using vendoring and the working directory is outside the repository.
         cargo.current_dir(&self.src);

src/bootstrap/src/core/config/config.rs

@@ -140,6 +140,7 @@ pub struct Config {
     pub config: Option<PathBuf>,
     pub jobs: Option<u32>,
     pub cmd: Subcommand,
+    pub quiet: bool,
     pub incremental: bool,
     pub dump_bootstrap_shims: bool,
     /// Arguments appearing after `--` to be forwarded to tools,
@@ -369,6 +370,7 @@ impl Config {
         let Flags {
             cmd: flags_cmd,
             verbose: flags_verbose,
+            quiet: flags_quiet,
             incremental: flags_incremental,
             config: flags_config,
             build_dir: flags_build_dir,
@@ -1433,6 +1435,7 @@ impl Config {
             print_step_timings: build_print_step_timings.unwrap_or(false),
             profiler: build_profiler.unwrap_or(false),
             python: build_python.map(PathBuf::from),
+            quiet: flags_quiet,
             reproducible_artifacts: flags_reproducible_artifact,
             reuse: build_reuse.map(PathBuf::from),
             rust_analyzer_info,

src/bootstrap/src/core/config/flags.rs

@@ -46,9 +46,12 @@ pub struct Flags {
     #[command(subcommand)]
     pub cmd: Subcommand,
 
-    #[arg(global = true, short, long, action = clap::ArgAction::Count)]
+    #[arg(global = true, short, long, action = clap::ArgAction::Count, conflicts_with = "quiet")]
     /// use verbose output (-vv for very verbose)
     pub verbose: u8, // each extra -v after the first is passed to Cargo
+    #[arg(global = true, short, long, conflicts_with = "verbose")]
+    /// use quiet output
+    pub quiet: bool,
     #[arg(global = true, short, long)]
     /// use incremental compilation
     pub incremental: bool,