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_session::config::OutputType;
  65
  66 use crate::prelude::*;
  67
  68 #[derive(Debug)]
  69 pub(crate) struct CommentWriter {
  70     global_comments: Vec<String>,
  71     entity_comments: FxHashMap<AnyEntity, String>,
  72 }
  73
  74 impl CommentWriter {
  75     pub(crate) fn new<'tcx>(tcx: TyCtxt<'tcx>, instance: Instance<'tcx>) -> Self {
  76         let global_comments = if cfg!(debug_assertions) {
  77             vec![
  78                 format!("symbol {}", tcx.symbol_name(instance).name),
  79                 format!("instance {:?}", instance),
  80                 format!(
  81                     "sig {:?}",
  82                     tcx.normalize_erasing_late_bound_regions(
  83                         ParamEnv::reveal_all(),
  84                         crate::abi::fn_sig_for_fn_abi(tcx, instance)
  85                     )
  86                 ),
  87                 String::new(),
  88             ]
  89         } else {
  90             vec![]
  91         };
  92
  93         CommentWriter {
  94             global_comments,
  95             entity_comments: FxHashMap::default(),
  96         }
  97     }
  98 }
  99
 100 #[cfg(debug_assertions)]
 101 impl CommentWriter {
 102     pub(crate) fn add_global_comment<S: Into<String>>(&mut self, comment: S) {
 103         self.global_comments.push(comment.into());
 104     }
 105
 106     pub(crate) fn add_comment<S: Into<String> + AsRef<str>, E: Into<AnyEntity>>(
 107         &mut self,
 108         entity: E,
 109         comment: S,
 110     ) {
 111         use std::collections::hash_map::Entry;
 112         match self.entity_comments.entry(entity.into()) {
 113             Entry::Occupied(mut occ) => {
 114                 occ.get_mut().push('\n');
 115                 occ.get_mut().push_str(comment.as_ref());
 116             }
 117             Entry::Vacant(vac) => {
 118                 vac.insert(comment.into());
 119             }
 120         }
 121     }
 122 }
 123
 124 impl FuncWriter for &'_ CommentWriter {
 125     fn write_preamble(
 126         &mut self,
 127         w: &mut dyn fmt::Write,
 128         func: &Function,
 129         reg_info: Option<&isa::RegInfo>,
 130     ) -> Result<bool, fmt::Error> {
 131         for comment in &self.global_comments {
 132             if !comment.is_empty() {
 133                 writeln!(w, "; {}", comment)?;
 134             } else {
 135                 writeln!(w)?;
 136             }
 137         }
 138         if !self.global_comments.is_empty() {
 139             writeln!(w)?;
 140         }
 141
 142         self.super_preamble(w, func, reg_info)
 143     }
 144
 145     fn write_entity_definition(
 146         &mut self,
 147         w: &mut dyn fmt::Write,
 148         _func: &Function,
 149         entity: AnyEntity,
 150         value: &dyn fmt::Display,
 151     ) -> fmt::Result {
 152         write!(w, "    {} = {}", entity, value)?;
 153
 154         if let Some(comment) = self.entity_comments.get(&entity) {
 155             writeln!(w, " ; {}", comment.replace('\n', "\n; "))
 156         } else {
 157             writeln!(w)
 158         }
 159     }
 160
 161     fn write_block_header(
 162         &mut self,
 163         w: &mut dyn fmt::Write,
 164         func: &Function,
 165         isa: Option<&dyn isa::TargetIsa>,
 166         block: Block,
 167         indent: usize,
 168     ) -> fmt::Result {
 169         PlainWriter.write_block_header(w, func, isa, block, indent)
 170     }
 171
 172     fn write_instruction(
 173         &mut self,
 174         w: &mut dyn fmt::Write,
 175         func: &Function,
 176         aliases: &SecondaryMap<Value, Vec<Value>>,
 177         isa: Option<&dyn isa::TargetIsa>,
 178         inst: Inst,
 179         indent: usize,
 180     ) -> fmt::Result {
 181         PlainWriter.write_instruction(w, func, aliases, isa, inst, indent)?;
 182         if let Some(comment) = self.entity_comments.get(&inst.into()) {
 183             writeln!(w, "; {}", comment.replace('\n', "\n; "))?;
 184         }
 185         Ok(())
 186     }
 187 }
 188
 189 #[cfg(debug_assertions)]
 190 impl<M: Module> FunctionCx<'_, '_, M> {
 191     pub(crate) fn add_global_comment<S: Into<String>>(&mut self, comment: S) {
 192         self.clif_comments.add_global_comment(comment);
 193     }
 194
 195     pub(crate) fn add_comment<S: Into<String> + AsRef<str>, E: Into<AnyEntity>>(
 196         &mut self,
 197         entity: E,
 198         comment: S,
 199     ) {
 200         self.clif_comments.add_comment(entity, comment);
 201     }
 202 }
 203
 204 pub(crate) fn should_write_ir(tcx: TyCtxt<'_>) -> bool {
 205     cfg!(debug_assertions)
 206         || tcx
 207             .sess
 208             .opts
 209             .output_types
 210             .contains_key(&OutputType::LlvmAssembly)
 211 }
 212
 213 pub(crate) fn write_ir_file<'tcx>(
 214     tcx: TyCtxt<'tcx>,
 215     name: &str,
 216     write: impl FnOnce(&mut dyn Write) -> std::io::Result<()>,
 217 ) {
 218     if !should_write_ir(tcx) {
 219         return;
 220     }
 221
 222     let clif_output_dir = tcx.output_filenames(LOCAL_CRATE).with_extension("clif");
 223
 224     match std::fs::create_dir(&clif_output_dir) {
 225         Ok(()) => {}
 226         Err(err) if err.kind() == std::io::ErrorKind::AlreadyExists => {}
 227         res @ Err(_) => res.unwrap(),
 228     }
 229
 230     let clif_file_name = clif_output_dir.join(name);
 231
 232     let res: std::io::Result<()> = try {
 233         let mut file = std::fs::File::create(clif_file_name)?;
 234         write(&mut file)?;
 235     };
 236     if let Err(err) = res {
 237         tcx.sess.warn(&format!("error writing ir file: {}", err));
 238     }
 239 }
 240
 241 pub(crate) fn write_clif_file<'tcx>(
 242     tcx: TyCtxt<'tcx>,
 243     postfix: &str,
 244     isa: Option<&dyn cranelift_codegen::isa::TargetIsa>,
 245     instance: Instance<'tcx>,
 246     context: &cranelift_codegen::Context,
 247     mut clif_comments: &CommentWriter,
 248 ) {
 249     write_ir_file(
 250         tcx,
 251         &format!("{}.{}.clif", tcx.symbol_name(instance).name, postfix),
 252         |file| {
 253             let value_ranges = isa.map(|isa| {
 254                 context
 255                     .build_value_labels_ranges(isa)
 256                     .expect("value location ranges")
 257             });
 258
 259             let mut clif = String::new();
 260             cranelift_codegen::write::decorate_function(
 261                 &mut clif_comments,
 262                 &mut clif,
 263                 &context.func,
 264                 &DisplayFunctionAnnotations {
 265                     isa: Some(&*crate::build_isa(tcx.sess)),
 266                     value_ranges: value_ranges.as_ref(),
 267                 },
 268             )
 269             .unwrap();
 270
 271             writeln!(file, "test compile")?;
 272             writeln!(file, "set is_pic")?;
 273             writeln!(file, "set enable_simd")?;
 274             writeln!(file, "target {} haswell", crate::target_triple(tcx.sess))?;
 275             writeln!(file)?;
 276             file.write_all(clif.as_bytes())?;
 277             Ok(())
 278         },
 279     );
 280 }
 281
 282 impl<M: Module> fmt::Debug for FunctionCx<'_, '_, M> {
 283     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 284         writeln!(f, "{:?}", self.instance.substs)?;
 285         writeln!(f, "{:?}", self.local_map)?;
 286
 287         let mut clif = String::new();
 288         ::cranelift_codegen::write::decorate_function(
 289             &mut &self.clif_comments,
 290             &mut clif,
 291             &self.bcx.func,
 292             &DisplayFunctionAnnotations::default(),
 293         )
 294         .unwrap();
 295         writeln!(f, "\n{}", clif)
 296     }
 297 }