Add config option and cli arg for skip-llvm-rebuild

config.toml.example

@@ -14,6 +14,11 @@
 # =============================================================================
 [llvm]
 
+# Skip rebuilding LLVM. If set to true, `bootstrap.py` will not rebuild LLVM.
+# This can be used or overridden with the command-line arguments
+# --skip-llvm-rebuild and --no-skip-llvm-rebuild as well.
+# skip-llvm-rebuild = false
+
 # Indicates whether the LLVM build is a Release or Debug build
 #optimize = true
 

src/bootstrap/bootstrap.py

@@ -330,6 +330,7 @@ def __init__(self):
         self.use_locked_deps = ''
         self.use_vendored_sources = ''
         self.verbose = False
+        self.skip_llvm_rebuild = False
 
     def download_stage0(self):
         """Fetch the build system for Rust, written in Rust
@@ -734,6 +735,9 @@ def update_submodules(self):
             if module.endswith("llvm-project"):
                 if self.get_toml('llvm-config') and self.get_toml('lld') != 'true':
                     continue
+                if self.skip_llvm_rebuild:
+                    print("Skipping llvm-project rebuild")
+                    continue
             check = self.check_submodule(module, slow_submodules)
             filtered_submodules.append((module, check))
             submodules_names.append(module)
@@ -820,6 +824,10 @@ def bootstrap(help_triggered):
     parser.add_argument('--src')
     parser.add_argument('--clean', action='store_true')
     parser.add_argument('-v', '--verbose', action='count', default=0)
+    parser.add_argument('--skip-llvm-rebuild',
+                        dest='skip_llvm_rebuild', action='store_true', default=None)
+    parser.add_argument('--no-skip-llvm-rebuild',
+                        dest='skip_llvm_rebuild', action='store_false')
 
     args = [a for a in sys.argv if a != '-h' and a != '--help']
     args, _ = parser.parse_known_args(args)
@@ -840,6 +848,17 @@ def bootstrap(help_triggered):
     if config_verbose is not None:
         build.verbose = max(build.verbose, int(config_verbose))
 
+    config_skip_llvm_rebuild = build.get_toml('skip-llvm-rebuild')
+    if args.skip_llvm_rebuild is not None:
+        # explicit cli arg is the strongest truth, ignore config file
+        build.skip_llvm_rebuild = args.skip_llvm_rebuild
+    elif config_skip_llvm_rebuild is not None:
+        # explicit config arg, no cli arg, trust the config file
+        build.skip_llvm_rebuild = config_skip_llvm_rebuild == 'true'
+    else:
+        # no config, no cli arg, defaulting to not skipping
+        build.skip_llvm_rebuild = False
+
     build.use_vendored_sources = build.get_toml('vendor', 'build') == 'true'
 
     build.use_locked_deps = build.get_toml('locked-deps', 'build') == 'true'

src/bootstrap/config.rs

@@ -66,6 +66,7 @@ pub struct Config {
     pub backtrace_on_ice: bool,
 
     // llvm codegen options
+    pub skip_llvm_rebuild: bool,
     pub llvm_assertions: bool,
     pub llvm_optimize: bool,
     pub llvm_thin_lto: bool,
@@ -243,6 +244,7 @@ struct Install {
 #[derive(Deserialize, Default)]
 #[serde(deny_unknown_fields, rename_all = "kebab-case")]
 struct Llvm {
+    skip_llvm_rebuild: Option<bool>,
     optimize: Option<bool>,
     thin_lto: Option<bool>,
     release_debuginfo: Option<bool>,
@@ -513,6 +515,7 @@ impl Config {
             }
             set(&mut config.ninja, llvm.ninja);
             llvm_assertions = llvm.assertions;
+            set(&mut config.skip_llvm_rebuild, llvm.skip_llvm_rebuild);
             set(&mut config.llvm_optimize, llvm.optimize);
             set(&mut config.llvm_thin_lto, llvm.thin_lto);
             set(&mut config.llvm_release_debuginfo, llvm.release_debuginfo);