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