Auto merge of #69393 - Dylan-DPC:rollup-rxbd1zg, r=Dylan-DPC

[rust.git] / src / librustc_codegen_ssa / base.rs

diff --git a/src/librustc_codegen_ssa/base.rs b/src/librustc_codegen_ssa/base.rs
index 1f43a4027c5ffe34977c32828aca66ba0403d004..e9431d94863ef96a4eb87ff4ec1520cfccfa77cd 100644 (file)
--- a/src/librustc_codegen_ssa/base.rs
+++ b/src/librustc_codegen_ssa/base.rs
@@ -28,8 +28,8 @@
 use rustc::middle::codegen_fn_attrs::CodegenFnAttrs;
 use rustc::middle::cstore::EncodedMetadata;
 use rustc::middle::cstore::{self, LinkagePreference};
+use rustc::middle::lang_items;
 use rustc::middle::lang_items::StartFnLangItem;
-use rustc::middle::weak_lang_items;
 use rustc::mir::mono::{CodegenUnit, CodegenUnitNameBuilder, MonoItem};
 use rustc::session::config::{self, EntryFnType, Lto};
 use rustc::session::Session;
@@ -391,10 +391,12 @@ pub fn codegen_instance<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>>(
 
 /// Creates the `main` function which will initialize the rust runtime and call
 /// users main function.
-pub fn maybe_create_entry_wrapper<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(cx: &'a Bx::CodegenCx) {
+pub fn maybe_create_entry_wrapper<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
+    cx: &'a Bx::CodegenCx,
+) -> Option<Bx::Function> {
     let (main_def_id, span) = match cx.tcx().entry_fn(LOCAL_CRATE) {
         Some((def_id, _)) => (def_id, cx.tcx().def_span(def_id)),
-        None => return,
+        None => return None,
     };
 
     let instance = Instance::mono(cx.tcx(), main_def_id);
@@ -402,17 +404,15 @@ pub fn maybe_create_entry_wrapper<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(cx: &'
     if !cx.codegen_unit().contains_item(&MonoItem::Fn(instance)) {
         // We want to create the wrapper in the same codegen unit as Rust's main
         // function.
-        return;
+        return None;
     }
 
     let main_llfn = cx.get_fn_addr(instance);
 
-    let et = cx.tcx().entry_fn(LOCAL_CRATE).map(|e| e.1);
-    match et {
-        Some(EntryFnType::Main) => create_entry_fn::<Bx>(cx, span, main_llfn, main_def_id, true),
-        Some(EntryFnType::Start) => create_entry_fn::<Bx>(cx, span, main_llfn, main_def_id, false),
-        None => {} // Do nothing.
-    }
+    return cx.tcx().entry_fn(LOCAL_CRATE).map(|(_, et)| {
+        let use_start_lang_item = EntryFnType::Start != et;
+        create_entry_fn::<Bx>(cx, span, main_llfn, main_def_id, use_start_lang_item)
+    });
 
     fn create_entry_fn<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
         cx: &'a Bx::CodegenCx,
@@ -420,7 +420,7 @@ fn create_entry_fn<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
         rust_main: Bx::Value,
         rust_main_def_id: DefId,
         use_start_lang_item: bool,
-    ) {
+    ) -> Bx::Function {
         // The entry function is either `int main(void)` or `int main(int argc, char **argv)`,
         // depending on whether the target needs `argc` and `argv` to be passed in.
         let llfty = if cx.sess().target.target.options.main_needs_argc_argv {
@@ -481,6 +481,8 @@ fn create_entry_fn<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
         let result = bx.call(start_fn, &args, None);
         let cast = bx.intcast(result, cx.type_int(), true);
         bx.ret(cast);
+
+        llfn
     }
 }
 
@@ -845,11 +847,8 @@ pub fn new(tcx: TyCtxt<'_>) -> CrateInfo {
 
             // No need to look for lang items that are whitelisted and don't
             // actually need to exist.
-            let missing = missing
-                .iter()
-                .cloned()
-                .filter(|&l| !weak_lang_items::whitelisted(tcx, l))
-                .collect();
+            let missing =
+                missing.iter().cloned().filter(|&l| !lang_items::whitelisted(tcx, l)).collect();
             info.missing_lang_items.insert(cnum, missing);
         }