Refactor the cli of cg_clif

src/config.rs

@@ -1,21 +1,15 @@
-/// The mode to use for compilation.
-#[derive(Copy, Clone, Debug)]
-pub enum CodegenMode {
-    /// AOT compile the crate. This is the default.
-    Aot,
-    /// JIT compile and execute the crate.
-    Jit,
-    /// JIT compile and execute the crate, but only compile functions the first time they are used.
-    JitLazy,
-}
-
 /// Configuration of cg_clif as passed in through `-Cllvm-args` and various env vars.
 #[derive(Clone, Debug)]
 pub struct BackendConfig {
     /// Should the crate be AOT compiled or JIT executed.
     ///
-    /// Defaults to AOT compilation. Can be set using `-Cllvm-args=mode=...`.
-    pub codegen_mode: CodegenMode,
+    /// Defaults to AOT compilation. Can be set using `-Cllvm-args=jit-mode`.
+    pub jit_mode: bool,
+
+    /// When JIT executing should the lazy JIT mode be used.
+    ///
+    /// Defaults to false. Can be set using `-Cllvm-args=jit-lazy`.
+    pub lazy_jit: bool,
 
     /// When JIT mode is enable pass these arguments to the program.
     ///
@@ -27,7 +21,8 @@ impl BackendConfig {
     /// Parse the configuration passed in using `-Cllvm-args`.
     pub fn from_opts(opts: &[String]) -> Result<Self, String> {
         let mut config = BackendConfig {
-            codegen_mode: CodegenMode::Aot,
+            jit_mode: false,
+            lazy_jit: false,
             jit_args: match std::env::var("CG_CLIF_JIT_ARGS") {
                 Ok(args) => args.split(' ').map(|arg| arg.to_string()).collect(),
                 Err(std::env::VarError::NotPresent) => vec![],
@@ -43,20 +38,10 @@ impl BackendConfig {
                 // testing cg_clif.
                 continue;
             }
-            if let Some((name, value)) = opt.split_once('=') {
-                match name {
-                    "mode" => {
-                        config.codegen_mode = match value {
-                            "aot" => CodegenMode::Aot,
-                            "jit" => CodegenMode::Jit,
-                            "jit-lazy" => CodegenMode::JitLazy,
-                            _ => return Err(format!("Unknown codegen mode `{}`", value)),
-                        };
-                    }
-                    _ => return Err(format!("Unknown option `{}`", name)),
-                }
-            } else {
-                return Err(format!("Invalid option `{}`", opt));
+            match &**opt {
+                "jit-mode" => config.jit_mode = true,
+                "jit-lazy" => config.lazy_jit = true,
+                _ => return Err(format!("Unknown option `{}`", opt)),
             }
         }
 

src/driver/jit.rs

@@ -13,10 +13,10 @@ use rustc_middle::mir::mono::MonoItem;
 use rustc_session::Session;
 use rustc_span::sym;
 
+use crate::CodegenCx;
 use crate::debuginfo::TypeDebugContext;
 use crate::prelude::*;
 use crate::unwind_module::UnwindModule;
-use crate::{CodegenCx, CodegenMode};
 
 struct JitState {
     jit_module: UnwindModule<JITModule>,
@@ -79,7 +79,7 @@ fn create_jit_module(tcx: TyCtxt<'_>, hotswap: bool) -> (UnwindModule<JITModule>
     (jit_module, cx)
 }
 
-pub(crate) fn run_jit(tcx: TyCtxt<'_>, codegen_mode: CodegenMode, jit_args: Vec<String>) -> ! {
+pub(crate) fn run_jit(tcx: TyCtxt<'_>, jit_lazy: bool, jit_args: Vec<String>) -> ! {
     if !tcx.sess.opts.output_types.should_codegen() {
         tcx.dcx().fatal("JIT mode doesn't work with `cargo check`");
     }
@@ -88,8 +88,7 @@ pub(crate) fn run_jit(tcx: TyCtxt<'_>, codegen_mode: CodegenMode, jit_args: Vec<
         tcx.dcx().fatal("can't jit non-executable crate");
     }
 
-    let (mut jit_module, mut cx) =
-        create_jit_module(tcx, matches!(codegen_mode, CodegenMode::JitLazy));
+    let (mut jit_module, mut cx) = create_jit_module(tcx, jit_lazy);
     let mut cached_context = Context::new();
 
     let cgus = tcx.collect_and_partition_mono_items(()).codegen_units;
@@ -105,9 +104,10 @@ pub(crate) fn run_jit(tcx: TyCtxt<'_>, codegen_mode: CodegenMode, jit_args: Vec<
         super::predefine_mono_items(tcx, &mut jit_module, &mono_items);
         for (mono_item, _) in mono_items {
             match mono_item {
-                MonoItem::Fn(inst) => match codegen_mode {
-                    CodegenMode::Aot => unreachable!(),
-                    CodegenMode::Jit => {
+                MonoItem::Fn(inst) => {
+                    if jit_lazy {
+                        codegen_shim(tcx, &mut cached_context, &mut jit_module, inst)
+                    } else {
                         codegen_and_compile_fn(
                             tcx,
                             &mut cx,
@@ -116,10 +116,7 @@ pub(crate) fn run_jit(tcx: TyCtxt<'_>, codegen_mode: CodegenMode, jit_args: Vec<
                             inst,
                         );
                     }
-                    CodegenMode::JitLazy => {
-                        codegen_shim(tcx, &mut cached_context, &mut jit_module, inst)
-                    }
-                },
+                }
                 MonoItem::Static(def_id) => {
                     crate::constant::codegen_static(tcx, &mut jit_module, def_id);
                 }

src/lib.rs

@@ -213,15 +213,14 @@ impl CodegenBackend for CraneliftCodegenBackend {
             BackendConfig::from_opts(&tcx.sess.opts.cg.llvm_args)
                 .unwrap_or_else(|err| tcx.sess.dcx().fatal(err))
         });
-        match config.codegen_mode {
-            CodegenMode::Aot => driver::aot::run_aot(tcx, metadata, need_metadata_module),
-            CodegenMode::Jit | CodegenMode::JitLazy => {
-                #[cfg(feature = "jit")]
-                driver::jit::run_jit(tcx, config.codegen_mode, config.jit_args);
+        if config.jit_mode {
+            #[cfg(feature = "jit")]
+            driver::jit::run_jit(tcx, config.lazy_jit, config.jit_args);
 
-                #[cfg(not(feature = "jit"))]
-                tcx.dcx().fatal("jit support was disabled when compiling rustc_codegen_cranelift");
-            }
+            #[cfg(not(feature = "jit"))]
+            tcx.dcx().fatal("jit support was disabled when compiling rustc_codegen_cranelift");
+        } else {
+            driver::aot::run_aot(tcx, metadata, need_metadata_module)
         }
     }