compiler/rustc_codegen_cranelift/src/abi/comments.rs

   1 //! Annotate the clif ir with comments describing how arguments are passed into the current function
   2 //! and where all locals are stored.
   3
   4 use std::borrow::Cow;
   5
   6 use rustc_middle::mir;
   7 use rustc_target::abi::call::PassMode;
   8
   9 use cranelift_codegen::entity::EntityRef;
  10
  11 use crate::prelude::*;
  12
  13 pub(super) fn add_args_header_comment(fx: &mut FunctionCx<'_, '_, impl Module>) {
  14     fx.add_global_comment(
  15         "kind  loc.idx   param    pass mode                            ty".to_string(),
  16     );
  17 }
  18
  19 pub(super) fn add_arg_comment<'tcx>(
  20     fx: &mut FunctionCx<'_, 'tcx, impl Module>,
  21     kind: &str,
  22     local: Option<mir::Local>,
  23     local_field: Option<usize>,
  24     params: &[Value],
  25     arg_abi_mode: PassMode,
  26     arg_layout: TyAndLayout<'tcx>,
  27 ) {
  28     let local = if let Some(local) = local {
  29         Cow::Owned(format!("{:?}", local))
  30     } else {
  31         Cow::Borrowed("???")
  32     };
  33     let local_field = if let Some(local_field) = local_field {
  34         Cow::Owned(format!(".{}", local_field))
  35     } else {
  36         Cow::Borrowed("")
  37     };
  38
  39     let params = match params {
  40         [] => Cow::Borrowed("-"),
  41         [param] => Cow::Owned(format!("= {:?}", param)),
  42         [param_a, param_b] => Cow::Owned(format!("= {:?},{:?}", param_a, param_b)),
  43         params => Cow::Owned(format!(
  44             "= {}",
  45             params
  46                 .iter()
  47                 .map(ToString::to_string)
  48                 .collect::<Vec<_>>()
  49                 .join(",")
  50         )),
  51     };
  52
  53     let pass_mode = format!("{:?}", arg_abi_mode);
  54     fx.add_global_comment(format!(
  55         "{kind:5}{local:>3}{local_field:<5} {params:10} {pass_mode:36} {ty:?}",
  56         kind = kind,
  57         local = local,
  58         local_field = local_field,
  59         params = params,
  60         pass_mode = pass_mode,
  61         ty = arg_layout.ty,
  62     ));
  63 }
  64
  65 pub(super) fn add_locals_header_comment(fx: &mut FunctionCx<'_, '_, impl Module>) {
  66     fx.add_global_comment(String::new());
  67     fx.add_global_comment(
  68         "kind  local ty                              size align (abi,pref)".to_string(),
  69     );
  70 }
  71
  72 pub(super) fn add_local_place_comments<'tcx>(
  73     fx: &mut FunctionCx<'_, 'tcx, impl Module>,
  74     place: CPlace<'tcx>,
  75     local: Local,
  76 ) {
  77     let TyAndLayout { ty, layout } = place.layout();
  78     let rustc_target::abi::Layout {
  79         size,
  80         align,
  81         abi: _,
  82         variants: _,
  83         fields: _,
  84         largest_niche: _,
  85     } = layout;
  86
  87     let (kind, extra) = match *place.inner() {
  88         CPlaceInner::Var(place_local, var) => {
  89             assert_eq!(local, place_local);
  90             ("ssa", Cow::Owned(format!(",var={}", var.index())))
  91         }
  92         CPlaceInner::VarPair(place_local, var1, var2) => {
  93             assert_eq!(local, place_local);
  94             (
  95                 "ssa",
  96                 Cow::Owned(format!(",var=({}, {})", var1.index(), var2.index())),
  97             )
  98         }
  99         CPlaceInner::VarLane(_local, _var, _lane) => unreachable!(),
 100         CPlaceInner::Addr(ptr, meta) => {
 101             let meta = if let Some(meta) = meta {
 102                 Cow::Owned(format!(",meta={}", meta))
 103             } else {
 104                 Cow::Borrowed("")
 105             };
 106             match ptr.base_and_offset() {
 107                 (crate::pointer::PointerBase::Addr(addr), offset) => (
 108                     "reuse",
 109                     format!("storage={}{}{}", addr, offset, meta).into(),
 110                 ),
 111                 (crate::pointer::PointerBase::Stack(stack_slot), offset) => (
 112                     "stack",
 113                     format!("storage={}{}{}", stack_slot, offset, meta).into(),
 114                 ),
 115                 (crate::pointer::PointerBase::Dangling(align), offset) => (
 116                     "zst",
 117                     format!("align={},offset={}", align.bytes(), offset).into(),
 118                 ),
 119             }
 120         }
 121     };
 122
 123     fx.add_global_comment(format!(
 124         "{:<5} {:5} {:30} {:4}b {}, {}{}{}",
 125         kind,
 126         format!("{:?}", local),
 127         format!("{:?}", ty),
 128         size.bytes(),
 129         align.abi.bytes(),
 130         align.pref.bytes(),
 131         if extra.is_empty() {
 132             ""
 133         } else {
 134             "              "
 135         },
 136         extra,
 137     ));
 138 }