rust/src/pretty_clif.rs
2023-12-18 16:06:21 +11:00

282 lines
11 KiB
Rust

//! This module provides the [CommentWriter] which makes it possible
//! to add comments to the written cranelift ir.
//!
//! # Example
//!
//! ```clif
//! test compile
//! target x86_64
//!
//! function u0:22(i64) -> i8, i8 system_v {
//! ; symbol _ZN97_$LT$example..IsNotEmpty$u20$as$u20$mini_core..FnOnce$LT$$LP$$RF$$RF$$u5b$u16$u5d$$C$$RP$$GT$$GT$9call_once17hd517c453d67c0915E
//! ; instance Instance { def: Item(WithOptConstParam { did: DefId(0:42 ~ example[4e51]::{impl#0}::call_once), const_param_did: None }), args: [ReErased, ReErased] }
//! ; abi FnAbi { args: [ArgAbi { layout: TyAndLayout { ty: IsNotEmpty, layout: Layout { size: Size(0 bytes), align: AbiAndPrefAlign { abi: Align(1 bytes), pref: Align(8 bytes) }, abi: Aggregate { sized: true }, fields: Arbitrary { offsets: [], memory_index: [] }, largest_niche: None, variants: Single { index: 0 } } }, mode: Ignore }, ArgAbi { layout: TyAndLayout { ty: &&[u16], layout: Layout { size: Size(8 bytes), align: AbiAndPrefAlign { abi: Align(8 bytes), pref: Align(8 bytes) }, abi: Scalar(Initialized { value: Pointer(AddressSpace(0)), valid_range: 1..=18446744073709551615 }), fields: Primitive, largest_niche: Some(Niche { offset: Size(0 bytes), value: Pointer(AddressSpace(0)), valid_range: 1..=18446744073709551615 }), variants: Single { index: 0 } } }, mode: Direct(ArgAttributes { regular: NonNull | NoUndef, arg_ext: None, pointee_size: Size(0 bytes), pointee_align: Some(Align(8 bytes)) }) }], ret: ArgAbi { layout: TyAndLayout { ty: (u8, u8), layout: Layout { size: Size(2 bytes), align: AbiAndPrefAlign { abi: Align(1 bytes), pref: Align(8 bytes) }, abi: ScalarPair(Initialized { value: Int(I8, false), valid_range: 0..=255 }, Initialized { value: Int(I8, false), valid_range: 0..=255 }), fields: Arbitrary { offsets: [Size(0 bytes), Size(1 bytes)], memory_index: [0, 1] }, largest_niche: None, variants: Single { index: 0 } } }, mode: Pair(ArgAttributes { regular: NoUndef, arg_ext: None, pointee_size: Size(0 bytes), pointee_align: None }, ArgAttributes { regular: NoUndef, arg_ext: None, pointee_size: Size(0 bytes), pointee_align: None }) }, c_variadic: false, fixed_count: 1, conv: Rust, can_unwind: false }
//!
//! ; kind loc.idx param pass mode ty
//! ; ssa _0 (u8, u8) 2b 1, 8 var=(0, 1)
//! ; ret _0 - Pair(ArgAttributes { regular: NoUndef, arg_ext: None, pointee_size: Size(0 bytes), pointee_align: None }, ArgAttributes { regular: NoUndef, arg_ext: None, pointee_size: Size(0 bytes), pointee_align: None }) (u8, u8)
//! ; arg _1 - Ignore IsNotEmpty
//! ; arg _2.0 = v0 Direct(ArgAttributes { regular: NonNull | NoUndef, arg_ext: None, pointee_size: Size(0 bytes), pointee_align: Some(Align(8 bytes)) }) &&[u16]
//!
//! ; kind local ty size align (abi,pref)
//! ; zst _1 IsNotEmpty 0b 1, 8 align=8,offset=
//! ; stack _2 (&&[u16],) 8b 8, 8 storage=ss0
//! ; ssa _3 &mut IsNotEmpty 8b 8, 8 var=2
//!
//! ss0 = explicit_slot 16
//! sig0 = (i64, i64) -> i8, i8 system_v
//! fn0 = colocated u0:23 sig0 ; Instance { def: Item(WithOptConstParam { did: DefId(0:46 ~ example[4e51]::{impl#1}::call_mut), const_param_did: None }), args: [ReErased, ReErased] }
//!
//! block0(v0: i64):
//! nop
//! ; write_cvalue: Addr(Pointer { base: Stack(ss0), offset: Offset32(0) }, None): &&[u16] <- ByVal(v0): &&[u16]
//! stack_store v0, ss0
//! jump block1
//!
//! block1:
//! nop
//! ; _3 = &mut _1
//! v1 = iconst.i64 8
//! ; write_cvalue: Var(_3, var2): &mut IsNotEmpty <- ByVal(v1): &mut IsNotEmpty
//! ;
//! ; _0 = <IsNotEmpty as mini_core::FnMut<(&&[u16],)>>::call_mut(move _3, _2)
//! v2 = stack_load.i64 ss0
//! v3, v4 = call fn0(v1, v2) ; v1 = 8
//! v5 -> v3
//! v6 -> v4
//! ; write_cvalue: VarPair(_0, var0, var1): (u8, u8) <- ByValPair(v3, v4): (u8, u8)
//! jump block2
//!
//! block2:
//! nop
//! ;
//! ; return
//! return v5, v6
//! }
//! ```
use std::fmt;
use std::io::Write;
use cranelift_codegen::entity::SecondaryMap;
use cranelift_codegen::ir::entities::AnyEntity;
use cranelift_codegen::ir::Fact;
use cranelift_codegen::write::{FuncWriter, PlainWriter};
use rustc_middle::ty::layout::FnAbiOf;
use rustc_middle::ty::print::with_no_trimmed_paths;
use rustc_session::config::{OutputFilenames, OutputType};
use crate::prelude::*;
#[derive(Clone, Debug)]
pub(crate) struct CommentWriter {
enabled: bool,
global_comments: Vec<String>,
entity_comments: FxHashMap<AnyEntity, String>,
}
impl CommentWriter {
pub(crate) fn new<'tcx>(tcx: TyCtxt<'tcx>, instance: Instance<'tcx>) -> Self {
let enabled = should_write_ir(tcx);
let global_comments = if enabled {
with_no_trimmed_paths!({
vec![
format!("symbol {}", tcx.symbol_name(instance).name),
format!("instance {:?}", instance),
format!(
"abi {:?}",
RevealAllLayoutCx(tcx).fn_abi_of_instance(instance, ty::List::empty())
),
String::new(),
]
})
} else {
vec![]
};
CommentWriter { enabled, global_comments, entity_comments: FxHashMap::default() }
}
}
impl CommentWriter {
pub(crate) fn enabled(&self) -> bool {
self.enabled
}
pub(crate) fn add_global_comment<S: Into<String>>(&mut self, comment: S) {
debug_assert!(self.enabled);
self.global_comments.push(comment.into());
}
pub(crate) fn add_comment<S: Into<String> + AsRef<str>, E: Into<AnyEntity>>(
&mut self,
entity: E,
comment: S,
) {
debug_assert!(self.enabled);
use std::collections::hash_map::Entry;
match self.entity_comments.entry(entity.into()) {
Entry::Occupied(mut occ) => {
occ.get_mut().push('\n');
occ.get_mut().push_str(comment.as_ref());
}
Entry::Vacant(vac) => {
vac.insert(comment.into());
}
}
}
}
impl FuncWriter for &'_ CommentWriter {
fn write_preamble(
&mut self,
w: &mut dyn fmt::Write,
func: &Function,
) -> Result<bool, fmt::Error> {
for comment in &self.global_comments {
if !comment.is_empty() {
writeln!(w, "; {}", comment)?;
} else {
writeln!(w)?;
}
}
if !self.global_comments.is_empty() {
writeln!(w)?;
}
self.super_preamble(w, func)
}
fn write_entity_definition(
&mut self,
w: &mut dyn fmt::Write,
_func: &Function,
entity: AnyEntity,
value: &dyn fmt::Display,
maybe_fact: Option<&Fact>,
) -> fmt::Result {
if let Some(fact) = maybe_fact {
write!(w, " {} ! {} = {}", entity, fact, value)?;
} else {
write!(w, " {} = {}", entity, value)?;
}
if let Some(comment) = self.entity_comments.get(&entity) {
writeln!(w, " ; {}", comment.replace('\n', "\n; "))
} else {
writeln!(w)
}
}
fn write_block_header(
&mut self,
w: &mut dyn fmt::Write,
func: &Function,
block: Block,
indent: usize,
) -> fmt::Result {
PlainWriter.write_block_header(w, func, block, indent)
}
fn write_instruction(
&mut self,
w: &mut dyn fmt::Write,
func: &Function,
aliases: &SecondaryMap<Value, Vec<Value>>,
inst: Inst,
indent: usize,
) -> fmt::Result {
PlainWriter.write_instruction(w, func, aliases, inst, indent)?;
if let Some(comment) = self.entity_comments.get(&inst.into()) {
writeln!(w, "; {}", comment.replace('\n', "\n; "))?;
}
Ok(())
}
}
impl FunctionCx<'_, '_, '_> {
pub(crate) fn add_global_comment<S: Into<String>>(&mut self, comment: S) {
self.clif_comments.add_global_comment(comment);
}
pub(crate) fn add_comment<S: Into<String> + AsRef<str>, E: Into<AnyEntity>>(
&mut self,
entity: E,
comment: S,
) {
self.clif_comments.add_comment(entity, comment);
}
}
pub(crate) fn should_write_ir(tcx: TyCtxt<'_>) -> bool {
tcx.sess.opts.output_types.contains_key(&OutputType::LlvmAssembly)
}
pub(crate) fn write_ir_file(
output_filenames: &OutputFilenames,
name: &str,
write: impl FnOnce(&mut dyn Write) -> std::io::Result<()>,
) {
let clif_output_dir = output_filenames.with_extension("clif");
match std::fs::create_dir(&clif_output_dir) {
Ok(()) => {}
Err(err) if err.kind() == std::io::ErrorKind::AlreadyExists => {}
res @ Err(_) => res.unwrap(),
}
let clif_file_name = clif_output_dir.join(name);
let res = std::fs::File::create(clif_file_name).and_then(|mut file| write(&mut file));
if let Err(err) = res {
// Using early_warn as no Session is available here
let handler =
rustc_session::EarlyDiagCtxt::new(rustc_session::config::ErrorOutputType::default());
handler.early_warn(format!("error writing ir file: {}", err));
}
}
pub(crate) fn write_clif_file(
output_filenames: &OutputFilenames,
symbol_name: &str,
postfix: &str,
isa: &dyn cranelift_codegen::isa::TargetIsa,
func: &cranelift_codegen::ir::Function,
mut clif_comments: &CommentWriter,
) {
// FIXME work around filename too long errors
write_ir_file(output_filenames, &format!("{}.{}.clif", symbol_name, postfix), |file| {
let mut clif = String::new();
cranelift_codegen::write::decorate_function(&mut clif_comments, &mut clif, func).unwrap();
for flag in isa.flags().iter() {
writeln!(file, "set {}", flag)?;
}
write!(file, "target {}", isa.triple().architecture)?;
for isa_flag in isa.isa_flags().iter() {
write!(file, " {}", isa_flag)?;
}
writeln!(file, "\n")?;
writeln!(file)?;
file.write_all(clif.as_bytes())?;
Ok(())
});
}
impl fmt::Debug for FunctionCx<'_, '_, '_> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
writeln!(f, "{:?}", self.instance.args)?;
writeln!(f, "{:?}", self.local_map)?;
let mut clif = String::new();
::cranelift_codegen::write::decorate_function(
&mut &self.clif_comments,
&mut clif,
&self.bcx.func,
)
.unwrap();
writeln!(f, "\n{}", clif)
}
}