compiler/rustc_codegen_cranelift/src/pretty_clif.rs

   1 //! This module provides the [CommentWriter] which makes it possible
   2 //! to add comments to the written cranelift ir.
   3 //!
   4 //! # Example
   5 //!
   6 //! ```clif
   7 //! test compile
   8 //! target x86_64
   9 //!
  10 //! function u0:0(i64, i64, i64) system_v {
  11 //! ; symbol _ZN119_$LT$example..IsNotEmpty$u20$as$u20$mini_core..FnOnce$LT$$LP$$RF$$u27$a$u20$$RF$$u27$b$u20$$u5b$u16$u5d$$C$$RP$$GT$$GT$9call_once17he85059d5e6a760a0E
  12 //! ; instance Instance { def: Item(DefId(0/0:29 ~ example[8787]::{{impl}}[0]::call_once[0])), substs: [ReErased, ReErased] }
  13 //! ; sig ([IsNotEmpty, (&&[u16],)]; c_variadic: false)->(u8, u8)
  14 //!
  15 //! ; ssa {_2: NOT_SSA, _4: NOT_SSA, _0: NOT_SSA, _3: (empty), _1: NOT_SSA}
  16 //! ; msg   loc.idx    param    pass mode            ssa flags  ty
  17 //! ; ret    _0      = v0       ByRef                NOT_SSA    (u8, u8)
  18 //! ; arg    _1      = v1       ByRef                NOT_SSA    IsNotEmpty
  19 //! ; arg    _2.0    = v2       ByVal(types::I64)    NOT_SSA    &&[u16]
  20 //!
  21 //!     ss0 = explicit_slot 0 ; _1: IsNotEmpty size=0 align=1,8
  22 //!     ss1 = explicit_slot 8 ; _2: (&&[u16],) size=8 align=8,8
  23 //!     ss2 = explicit_slot 8 ; _4: (&&[u16],) size=8 align=8,8
  24 //!     sig0 = (i64, i64, i64) system_v
  25 //!     sig1 = (i64, i64, i64) system_v
  26 //!     fn0 = colocated u0:6 sig1 ; Instance { def: Item(DefId(0/0:31 ~ example[8787]::{{impl}}[1]::call_mut[0])), substs: [ReErased, ReErased] }
  27 //!
  28 //! block0(v0: i64, v1: i64, v2: i64):
  29 //!     v3 = stack_addr.i64 ss0
  30 //!     v4 = stack_addr.i64 ss1
  31 //!     store v2, v4
  32 //!     v5 = stack_addr.i64 ss2
  33 //!     jump block1
  34 //!
  35 //! block1:
  36 //!     nop
  37 //! ; _3 = &mut _1
  38 //! ; _4 = _2
  39 //!     v6 = load.i64 v4
  40 //!     store v6, v5
  41 //! ;
  42 //! ; _0 = const mini_core::FnMut::call_mut(move _3, move _4)
  43 //!     v7 = load.i64 v5
  44 //!     call fn0(v0, v3, v7)
  45 //!     jump block2
  46 //!
  47 //! block2:
  48 //!     nop
  49 //! ;
  50 //! ; return
  51 //!     return
  52 //! }
  53 //! ```
  54
  55 use std::fmt;
  56 use std::io::Write;
  57
  58 use cranelift_codegen::{
  59     entity::SecondaryMap,
  60     ir::{entities::AnyEntity, function::DisplayFunctionAnnotations},
  61     write::{FuncWriter, PlainWriter},
  62 };
  63
  64 use rustc_middle::ty::layout::FnAbiExt;
  65 use rustc_session::config::OutputType;
  66 use rustc_target::abi::call::FnAbi;
  67
  68 use crate::prelude::*;
  69
  70 #[derive(Debug)]
  71 pub(crate) struct CommentWriter {
  72     global_comments: Vec<String>,
  73     entity_comments: FxHashMap<AnyEntity, String>,
  74 }
  75
  76 impl CommentWriter {
  77     pub(crate) fn new<'tcx>(tcx: TyCtxt<'tcx>, instance: Instance<'tcx>) -> Self {
  78         let global_comments = if cfg!(debug_assertions) {
  79             vec![
  80                 format!("symbol {}", tcx.symbol_name(instance).name),
  81                 format!("instance {:?}", instance),
  82                 format!("abi {:?}", FnAbi::of_instance(&RevealAllLayoutCx(tcx), instance, &[])),
  83                 String::new(),
  84             ]
  85         } else {
  86             vec![]
  87         };
  88
  89         CommentWriter { global_comments, entity_comments: FxHashMap::default() }
  90     }
  91 }
  92
  93 #[cfg(debug_assertions)]
  94 impl CommentWriter {
  95     pub(crate) fn add_global_comment<S: Into<String>>(&mut self, comment: S) {
  96         self.global_comments.push(comment.into());
  97     }
  98
  99     pub(crate) fn add_comment<S: Into<String> + AsRef<str>, E: Into<AnyEntity>>(
 100         &mut self,
 101         entity: E,
 102         comment: S,
 103     ) {
 104         use std::collections::hash_map::Entry;
 105         match self.entity_comments.entry(entity.into()) {
 106             Entry::Occupied(mut occ) => {
 107                 occ.get_mut().push('\n');
 108                 occ.get_mut().push_str(comment.as_ref());
 109             }
 110             Entry::Vacant(vac) => {
 111                 vac.insert(comment.into());
 112             }
 113         }
 114     }
 115 }
 116
 117 impl FuncWriter for &'_ CommentWriter {
 118     fn write_preamble(
 119         &mut self,
 120         w: &mut dyn fmt::Write,
 121         func: &Function,
 122         reg_info: Option<&isa::RegInfo>,
 123     ) -> Result<bool, fmt::Error> {
 124         for comment in &self.global_comments {
 125             if !comment.is_empty() {
 126                 writeln!(w, "; {}", comment)?;
 127             } else {
 128                 writeln!(w)?;
 129             }
 130         }
 131         if !self.global_comments.is_empty() {
 132             writeln!(w)?;
 133         }
 134
 135         self.super_preamble(w, func, reg_info)
 136     }
 137
 138     fn write_entity_definition(
 139         &mut self,
 140         w: &mut dyn fmt::Write,
 141         _func: &Function,
 142         entity: AnyEntity,
 143         value: &dyn fmt::Display,
 144     ) -> fmt::Result {
 145         write!(w, "    {} = {}", entity, value)?;
 146
 147         if let Some(comment) = self.entity_comments.get(&entity) {
 148             writeln!(w, " ; {}", comment.replace('\n', "\n; "))
 149         } else {
 150             writeln!(w)
 151         }
 152     }
 153
 154     fn write_block_header(
 155         &mut self,
 156         w: &mut dyn fmt::Write,
 157         func: &Function,
 158         isa: Option<&dyn isa::TargetIsa>,
 159         block: Block,
 160         indent: usize,
 161     ) -> fmt::Result {
 162         PlainWriter.write_block_header(w, func, isa, block, indent)
 163     }
 164
 165     fn write_instruction(
 166         &mut self,
 167         w: &mut dyn fmt::Write,
 168         func: &Function,
 169         aliases: &SecondaryMap<Value, Vec<Value>>,
 170         isa: Option<&dyn isa::TargetIsa>,
 171         inst: Inst,
 172         indent: usize,
 173     ) -> fmt::Result {
 174         PlainWriter.write_instruction(w, func, aliases, isa, inst, indent)?;
 175         if let Some(comment) = self.entity_comments.get(&inst.into()) {
 176             writeln!(w, "; {}", comment.replace('\n', "\n; "))?;
 177         }
 178         Ok(())
 179     }
 180 }
 181
 182 #[cfg(debug_assertions)]
 183 impl FunctionCx<'_, '_, '_> {
 184     pub(crate) fn add_global_comment<S: Into<String>>(&mut self, comment: S) {
 185         self.clif_comments.add_global_comment(comment);
 186     }
 187
 188     pub(crate) fn add_comment<S: Into<String> + AsRef<str>, E: Into<AnyEntity>>(
 189         &mut self,
 190         entity: E,
 191         comment: S,
 192     ) {
 193         self.clif_comments.add_comment(entity, comment);
 194     }
 195 }
 196
 197 pub(crate) fn should_write_ir(tcx: TyCtxt<'_>) -> bool {
 198     tcx.sess.opts.output_types.contains_key(&OutputType::LlvmAssembly)
 199 }
 200
 201 pub(crate) fn write_ir_file<'tcx>(
 202     tcx: TyCtxt<'tcx>,
 203     name: &str,
 204     write: impl FnOnce(&mut dyn Write) -> std::io::Result<()>,
 205 ) {
 206     if !should_write_ir(tcx) {
 207         return;
 208     }
 209
 210     let clif_output_dir = tcx.output_filenames(LOCAL_CRATE).with_extension("clif");
 211
 212     match std::fs::create_dir(&clif_output_dir) {
 213         Ok(()) => {}
 214         Err(err) if err.kind() == std::io::ErrorKind::AlreadyExists => {}
 215         res @ Err(_) => res.unwrap(),
 216     }
 217
 218     let clif_file_name = clif_output_dir.join(name);
 219
 220     let res: std::io::Result<()> = try {
 221         let mut file = std::fs::File::create(clif_file_name)?;
 222         write(&mut file)?;
 223     };
 224     if let Err(err) = res {
 225         tcx.sess.warn(&format!("error writing ir file: {}", err));
 226     }
 227 }
 228
 229 pub(crate) fn write_clif_file<'tcx>(
 230     tcx: TyCtxt<'tcx>,
 231     postfix: &str,
 232     isa: Option<&dyn cranelift_codegen::isa::TargetIsa>,
 233     instance: Instance<'tcx>,
 234     context: &cranelift_codegen::Context,
 235     mut clif_comments: &CommentWriter,
 236 ) {
 237     write_ir_file(tcx, &format!("{}.{}.clif", tcx.symbol_name(instance).name, postfix), |file| {
 238         let value_ranges =
 239             isa.map(|isa| context.build_value_labels_ranges(isa).expect("value location ranges"));
 240
 241         let mut clif = String::new();
 242         cranelift_codegen::write::decorate_function(
 243             &mut clif_comments,
 244             &mut clif,
 245             &context.func,
 246             &DisplayFunctionAnnotations {
 247                 isa: Some(&*crate::build_isa(tcx.sess)),
 248                 value_ranges: value_ranges.as_ref(),
 249             },
 250         )
 251         .unwrap();
 252
 253         writeln!(file, "test compile")?;
 254         writeln!(file, "set is_pic")?;
 255         writeln!(file, "set enable_simd")?;
 256         writeln!(file, "target {} haswell", crate::target_triple(tcx.sess))?;
 257         writeln!(file)?;
 258         file.write_all(clif.as_bytes())?;
 259         Ok(())
 260     });
 261 }
 262
 263 impl fmt::Debug for FunctionCx<'_, '_, '_> {
 264     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 265         writeln!(f, "{:?}", self.instance.substs)?;
 266         writeln!(f, "{:?}", self.local_map)?;
 267
 268         let mut clif = String::new();
 269         ::cranelift_codegen::write::decorate_function(
 270             &mut &self.clif_comments,
 271             &mut clif,
 272             &self.bcx.func,
 273             &DisplayFunctionAnnotations::default(),
 274         )
 275         .unwrap();
 276         writeln!(f, "\n{}", clif)
 277     }
 278 }