add the build.reuse config option to choose the reuse binary

config.toml.example

@@ -255,6 +255,13 @@ changelog-seen = 2
 # Defaults to the Python interpreter used to execute x.py
 #python = "python"
 
+# The path to the REUSE executable to use. REUSE will be used to gather
+# the licensing information of the codebase.
+#
+# If this is omitted, the cached licensing information present in the source
+# tarball will have to be present.
+#reuse = "reuse"
+
 # Force Cargo to check that Cargo.lock describes the precise dependency
 # set that all the Cargo.toml files create, instead of updating it.
 #locked-deps = false

src/bootstrap/config.rs

@@ -212,6 +212,7 @@ pub struct Config {
     pub npm: Option<PathBuf>,
     pub gdb: Option<PathBuf>,
     pub python: Option<PathBuf>,
+    pub reuse: Option<PathBuf>,
     pub cargo_native_static: bool,
     pub configure_args: Vec<String>,
 
@@ -610,6 +611,7 @@ define_config! {
         nodejs: Option<String> = "nodejs",
         npm: Option<String> = "npm",
         python: Option<String> = "python",
+        reuse: Option<String> = "reuse",
         locked_deps: Option<bool> = "locked-deps",
         vendor: Option<bool> = "vendor",
         full_bootstrap: Option<bool> = "full-bootstrap",
@@ -1003,6 +1005,7 @@ impl Config {
         config.npm = build.npm.map(PathBuf::from);
         config.gdb = build.gdb.map(PathBuf::from);
         config.python = build.python.map(PathBuf::from);
+        config.reuse = build.reuse.map(PathBuf::from);
         config.submodules = build.submodules;
         set(&mut config.low_priority, build.low_priority);
         set(&mut config.compiler_docs, build.compiler_docs);

src/bootstrap/sanity.rs

@@ -140,6 +140,13 @@ than building it.
         .map(|p| cmd_finder.must_have(p))
         .or_else(|| cmd_finder.maybe_have("gdb"));
 
+    build.config.reuse = build
+        .config
+        .reuse
+        .take()
+        .map(|p| cmd_finder.must_have(p))
+        .or_else(|| cmd_finder.maybe_have("reuse"));
+
     // We're gonna build some custom C code here and there, host triples
     // also build some C++ shims for LLVM so we need a C++ compiler.
     for target in &build.targets {