[bootstrap] Remove llvm.enabled config

Author: bjorn3

config.toml.example

@@ -14,10 +14,6 @@
 # =============================================================================
 [llvm]
 
-# Indicates whether rustc will support compilation with LLVM
-# note: rustc does not compile without LLVM at the moment
-#enabled = true
-
 # Indicates whether the LLVM build is a Release or Debug build
 #optimize = true
 

src/bootstrap/builder.rs

@@ -996,10 +996,7 @@ impl<'a> Builder<'a> {
         // For other crates, however, we know that we've already got a standard
         // library up and running, so we can use the normal compiler to compile
         // build scripts in that situation.
-        //
-        // If LLVM support is disabled we need to use the snapshot compiler to compile
-        // build scripts, as the new compiler doesn't support executables.
-        if mode == Mode::Std || !self.config.llvm_enabled {
+        if mode == Mode::Std {
             cargo
                 .env("RUSTC_SNAPSHOT", &self.initial_rustc)
                 .env("RUSTC_SNAPSHOT_LIBDIR", self.rustc_snapshot_libdir());

src/bootstrap/config.rs

@@ -64,7 +64,6 @@ pub struct Config {
     pub backtrace_on_ice: bool,
 
     // llvm codegen options
-    pub llvm_enabled: bool,
     pub llvm_assertions: bool,
     pub llvm_optimize: bool,
     pub llvm_thin_lto: bool,
@@ -244,7 +243,6 @@ struct Install {
 #[derive(Deserialize, Default)]
 #[serde(deny_unknown_fields, rename_all = "kebab-case")]
 struct Llvm {
-    enabled: Option<bool>,
     ccache: Option<StringOrBool>,
     ninja: Option<bool>,
     assertions: Option<bool>,
@@ -360,7 +358,6 @@ impl Config {
 
     pub fn default_opts() -> Config {
         let mut config = Config::default();
-        config.llvm_enabled = true;
         config.llvm_optimize = true;
         config.llvm_version_check = true;
         config.backtrace = true;
@@ -512,7 +509,6 @@ impl Config {
                 Some(StringOrBool::Bool(false)) | None => {}
             }
             set(&mut config.ninja, llvm.ninja);
-            set(&mut config.llvm_enabled, llvm.enabled);
             llvm_assertions = llvm.assertions;
             set(&mut config.llvm_optimize, llvm.optimize);
             set(&mut config.llvm_thin_lto, llvm.thin_lto);
@@ -671,6 +667,11 @@ impl Config {
     pub fn very_verbose(&self) -> bool {
         self.verbose > 1
     }
+
+    pub fn llvm_enabled(&self) -> bool {
+        self.rust_codegen_backends.contains(&INTERNER.intern_str("llvm"))
+        || self.rust_codegen_backends.contains(&INTERNER.intern_str("emscripten"))
+    }
 }
 
 fn set<T>(field: &mut T, val: Option<T>) {

src/bootstrap/test.rs

@@ -1194,7 +1194,7 @@ impl Step for Compiletest {
             cmd.arg("--quiet");
         }
 
-        if builder.config.llvm_enabled {
+        if builder.config.llvm_enabled() {
             let llvm_config = builder.ensure(native::Llvm {
                 target: builder.config.build,
                 emscripten: false,
@@ -1227,12 +1227,6 @@ impl Step for Compiletest {
                 }
             }
         }
-        if suite == "run-make-fulldeps" && !builder.config.llvm_enabled {
-            builder.info(
-                "Ignoring run-make test suite as they generally don't work without LLVM"
-            );
-            return;
-        }
 
         if suite != "run-make-fulldeps" {
             cmd.arg("--cc")

src/bootstrap/tool.rs

@@ -699,8 +699,8 @@ impl<'a> Builder<'a> {
         add_lib_path(lib_paths, cmd);
     }
 
-    fn llvm_bin_path(&self) -> Option<PathBuf> {
-        if self.config.llvm_enabled {
+fn llvm_bin_path(&self) -> Option<PathBuf> {
+        if self.config.llvm_enabled() {
             let llvm_config = self.ensure(native::Llvm {
                 target: self.config.build,
                 emscripten: false,