Codegen minicore

build.sh

@@ -14,7 +14,7 @@ fi
 
 RUSTC="rustc -Zcodegen-backend=$(pwd)/target/debug/librustc_codegen_cranelift.$dylib_ext -L crate=."
 
-$RUSTC examples/mini_core.rs --crate-name mini_core --crate-type lib &&
+SHOULD_CODEGEN=1 $RUSTC examples/mini_core.rs --crate-name mini_core --crate-type lib &&
 $RUSTC examples/example.rs --crate-type lib &&
 $RUSTC examples/mini_core_hello_world.rs --crate-type bin &&
 

src/abi.rs

@@ -278,7 +278,10 @@ pub fn codegen_fn_prelude<'a, 'tcx: 'a>(fx: &mut FunctionCx<'a, 'tcx>, start_ebb
         Spread(Vec<Value>),
     }
 
-    let func_params = fx.mir.args_iter().map(|local| {
+    let func_params = fx
+        .mir
+        .args_iter()
+        .map(|local| {
             let arg_ty = fx.monomorphize(&fx.mir.local_decls[local].ty);
 
             // Adapted from https://github.com/rust-lang/rust/blob/145155dc96757002c7b2e9de8489416e2fdbbd57/src/librustc_codegen_llvm/mir/mod.rs#L442-L482
@@ -295,14 +298,20 @@ pub fn codegen_fn_prelude<'a, 'tcx: 'a>(fx: &mut FunctionCx<'a, 'tcx>, start_ebb
 
                 let mut ebb_params = Vec::new();
                 for arg_ty in tupled_arg_tys.iter() {
-                let cton_type = get_pass_mode(fx.tcx, fx.self_sig().abi, arg_ty, false).get_param_ty(fx);
+                    let cton_type =
+                        get_pass_mode(fx.tcx, fx.self_sig().abi, arg_ty, false).get_param_ty(fx);
                     ebb_params.push(fx.bcx.append_ebb_param(start_ebb, cton_type));
                 }
 
                 (local, ArgKind::Spread(ebb_params), arg_ty)
             } else {
-            let cton_type = get_pass_mode(fx.tcx, fx.self_sig().abi, arg_ty, false).get_param_ty(fx);
+                let cton_type =
-            (local, ArgKind::Normal(fx.bcx.append_ebb_param(start_ebb, cton_type)), arg_ty)
+                    get_pass_mode(fx.tcx, fx.self_sig().abi, arg_ty, false).get_param_ty(fx);
+                (
+                    local,
+                    ArgKind::Normal(fx.bcx.append_ebb_param(start_ebb, cton_type)),
+                    arg_ty,
+                )
             }
         }).collect::<Vec<(Local, ArgKind, Ty)>>();
 

src/base.rs

@@ -50,13 +50,7 @@ pub fn trans_mono_item<'a, 'tcx: 'a>(
 
                 context.func = func;
                 // TODO: cranelift doesn't yet support some of the things needed
-                if cx
+                if should_codegen(cx.tcx) {
-                    .tcx
-                    .sess
-                    .crate_types
-                    .get()
-                    .contains(&CrateType::Executable)
-                {
                     cx.module.define_function(func_id, context).unwrap();
                     cx.defined_functions.push(func_id);
                 }
@@ -171,7 +165,7 @@ pub fn trans_fn<'a, 'tcx: 'a>(
             } => {
                 fx.bcx.ins().trap(TrapCode::User(0));
                 // TODO: prevent panics on large and negative disciminants
-                if false {
+                if should_codegen(fx.tcx) {
                     let discr = trans_operand(fx, discr).load_value(fx);
                     let mut jt_data = JumpTableData::new();
                     for (i, value) in values.iter().enumerate() {
@@ -382,13 +376,23 @@ fn trans_stmt<'a, 'tcx: 'a>(fx: &mut FunctionCx<'a, 'tcx>, cur_ebb: Ebb, stmt: &
                         | (TypeVariants::TyUint(_), TypeVariants::TyInt(_))
                         | (TypeVariants::TyUint(_), TypeVariants::TyUint(_)) => {
                             let from = operand.load_value(fx);
-                            let res = crate::common::cton_intcast(fx, from, fx.cton_type(to_ty).unwrap(), false);
+                            let res = crate::common::cton_intcast(
+                                fx,
+                                from,
+                                fx.cton_type(to_ty).unwrap(),
+                                false,
+                            );
                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
                         }
                         (TypeVariants::TyInt(_), TypeVariants::TyInt(_))
                         | (TypeVariants::TyInt(_), TypeVariants::TyUint(_)) => {
                             let from = operand.load_value(fx);
-                            let res = crate::common::cton_intcast(fx, from, fx.cton_type(to_ty).unwrap(), true);
+                            let res = crate::common::cton_intcast(
+                                fx,
+                                from,
+                                fx.cton_type(to_ty).unwrap(),
+                                true,
+                            );
                             lval.write_cvalue(fx, CValue::ByVal(res, dest_layout));
                         }
                         (TypeVariants::TyFloat(from_flt), TypeVariants::TyFloat(to_flt)) => {
@@ -552,7 +556,8 @@ pub fn trans_get_discriminant<'a, 'tcx: 'a>(
                     lldiscr,
                     *niche_variants.end() as u64 as i64,
                 );
-                let if_true = cton_intcast(fx, lldiscr, fx.cton_type(dest_layout.ty).unwrap(), false);
+                let if_true =
+                    cton_intcast(fx, lldiscr, fx.cton_type(dest_layout.ty).unwrap(), false);
                 let if_false = fx
                     .bcx
                     .ins()

src/lib.rs

@@ -89,6 +89,11 @@ mod prelude {
     pub use crate::common::*;
 
     pub use crate::CodegenCx;
+
+    pub fn should_codegen(tcx: TyCtxt) -> bool {
+        ::std::env::var("SHOULD_CODEGEN").is_ok()
+            || tcx.sess.crate_types.get().contains(&CrateType::Executable)
+    }
 }
 
 use crate::prelude::*;
@@ -317,6 +322,12 @@ impl CodegenBackend for CraneliftCodegenBackend {
             tcx.sess.warn(&format!("main returned {}", res));
 
             module.finish();
+        } else if should_codegen(tcx) {
+            for func_id in defined_functions {
+                module.finalize_function(func_id);
+            }
+
+            tcx.sess.warn("Finalized everything");
         }
 
         let mut translated_module: Module<FaerieBackend> = Module::new(