Merge pull request rust-lang#693 from bjorn3/abi_refactor

Abi handling refactor

Author: bjorn3

example/example.rs

@@ -202,3 +202,7 @@ fn get_sized_field_ref_from_unsized_type(u: &Unsized) -> &u8 {
 fn get_unsized_field_ref_from_unsized_type(u: &Unsized) -> &str {
     &u.1
 }
+
+pub fn reuse_byref_argument_storage(a: (u8, u16, u32)) -> u8 {
+    a.0
+}

src/abi/comments.rs

@@ -0,0 +1,108 @@
+use std::borrow::Cow;
+
+use rustc::mir;
+
+use crate::prelude::*;
+use crate::abi::pass_mode::*;
+
+pub fn add_args_header_comment(fx: &mut FunctionCx<impl Backend>) {
+    fx.add_global_comment(format!(
+        "kind  loc.idx   param    pass mode                            ty"
+    ));
+}
+
+pub fn add_arg_comment<'tcx>(
+    fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
+    kind: &str,
+    local: mir::Local,
+    local_field: Option<usize>,
+    params: EmptySinglePair<Value>,
+    pass_mode: PassMode,
+    ty: Ty<'tcx>,
+) {
+    let local_field = if let Some(local_field) = local_field {
+        Cow::Owned(format!(".{}", local_field))
+    } else {
+        Cow::Borrowed("")
+    };
+    let params = match params {
+        Empty => Cow::Borrowed("-"),
+        Single(param) => Cow::Owned(format!("= {:?}", param)),
+        Pair(param_a, param_b) => Cow::Owned(format!("= {:?}, {:?}", param_a, param_b)),
+    };
+    let pass_mode = format!("{:?}", pass_mode);
+    fx.add_global_comment(format!(
+        "{kind:5}{local:>3}{local_field:<5} {params:10} {pass_mode:36} {ty:?}",
+        kind = kind,
+        local = format!("{:?}", local),
+        local_field = local_field,
+        params = params,
+        pass_mode = pass_mode,
+        ty = ty,
+    ));
+}
+
+pub fn add_locals_header_comment(fx: &mut FunctionCx<impl Backend>) {
+    fx.add_global_comment(String::new());
+    fx.add_global_comment(format!(
+        "kind  local ty                   size  align (abi,pref)"
+    ));
+}
+
+pub fn add_local_place_comments<'tcx>(
+    fx: &mut FunctionCx<'_, 'tcx, impl Backend>,
+    place: CPlace<'tcx>,
+    local: Local,
+) {
+    let TyLayout { ty, details } = place.layout();
+    let ty::layout::LayoutDetails {
+        size,
+        align,
+        abi: _,
+        variants: _,
+        fields: _,
+        largest_niche: _,
+    } = details;
+    match *place.inner() {
+        CPlaceInner::Var(var) => {
+            assert_eq!(local, var);
+            fx.add_global_comment(format!(
+                "ssa   {:5} {:20} {:4}b {}, {}",
+                format!("{:?}", local),
+                format!("{:?}", ty),
+                size.bytes(),
+                align.abi.bytes(),
+                align.pref.bytes(),
+            ));
+        }
+        CPlaceInner::Stack(stack_slot) => fx.add_entity_comment(
+            stack_slot,
+            format!(
+                "{:?}: {:?} size={} align={},{}",
+                local,
+                ty,
+                size.bytes(),
+                align.abi.bytes(),
+                align.pref.bytes(),
+            ),
+        ),
+        CPlaceInner::NoPlace => fx.add_global_comment(format!(
+            "zst   {:5} {:20} {:4}b {}, {}",
+            format!("{:?}", local),
+            format!("{:?}", ty),
+            size.bytes(),
+            align.abi.bytes(),
+            align.pref.bytes(),
+        )),
+        CPlaceInner::Addr(addr, None) => fx.add_global_comment(format!(
+            "reuse {:5} {:20} {:4}b {}, {}              storage={}",
+            format!("{:?}", local),
+            format!("{:?}", ty),
+            size.bytes(),
+            align.abi.bytes(),
+            align.pref.bytes(),
+            addr,
+        )),
+        CPlaceInner::Addr(_, Some(_)) => unreachable!(),
+    }
+}