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