blob: c35c9e4da9f4846be217a9cabc0ed3205f56d0c9 [file] [log] [blame]
use rustc::hir::def_id::{DefId, LOCAL_CRATE};
use rustc::mir::*;
use rustc::mir::visit::Visitor;
use rustc::ty::{self, TyCtxt};
use rustc_data_structures::fx::FxHashMap;
use rustc_data_structures::indexed_vec::Idx;
use std::fmt::Display;
use std::fmt::Write as _;
use std::fs;
use std::io::{self, Write};
use std::path::{Path, PathBuf};
use super::graphviz::write_mir_fn_graphviz;
use crate::transform::MirSource;
const INDENT: &str = " ";
/// Alignment for lining up comments following MIR statements
pub(crate) const ALIGN: usize = 40;
/// An indication of where we are in the control flow graph. Used for printing
/// extra information in `dump_mir`
pub enum PassWhere {
/// We have not started dumping the control flow graph, but we are about to.
BeforeCFG,
/// We just finished dumping the control flow graph. This is right before EOF
AfterCFG,
/// We are about to start dumping the given basic block.
BeforeBlock(BasicBlock),
/// We are just about to dump the given statement or terminator.
BeforeLocation(Location),
/// We just dumped the given statement or terminator.
AfterLocation(Location),
/// We just dumped the terminator for a block but not the closing `}`.
AfterTerminator(BasicBlock),
}
/// If the session is properly configured, dumps a human-readable
/// representation of the mir into:
///
/// ```text
/// rustc.node<node_id>.<pass_num>.<pass_name>.<disambiguator>
/// ```
///
/// Output from this function is controlled by passing `-Z dump-mir=<filter>`,
/// where `<filter>` takes the following forms:
///
/// - `all` -- dump MIR for all fns, all passes, all everything
/// - a filter defined by a set of substrings combined with `&` and `|`
/// (`&` has higher precedence). At least one of the `|`-separated groups
/// must match; an `|`-separated group matches if all of its `&`-separated
/// substrings are matched.
///
/// Example:
///
/// - `nll` == match if `nll` appears in the name
/// - `foo & nll` == match if `foo` and `nll` both appear in the name
/// - `foo & nll | typeck` == match if `foo` and `nll` both appear in the name
/// or `typeck` appears in the name.
/// - `foo & nll | bar & typeck` == match if `foo` and `nll` both appear in the name
/// or `typeck` and `bar` both appear in the name.
pub fn dump_mir<'tcx, F>(
tcx: TyCtxt<'tcx>,
pass_num: Option<&dyn Display>,
pass_name: &str,
disambiguator: &dyn Display,
source: MirSource<'tcx>,
body: &Body<'tcx>,
extra_data: F,
) where
F: FnMut(PassWhere, &mut dyn Write) -> io::Result<()>,
{
if !dump_enabled(tcx, pass_name, source) {
return;
}
let node_path = ty::print::with_forced_impl_filename_line(|| {
// see notes on #41697 below
tcx.def_path_str(source.def_id())
});
dump_matched_mir_node(
tcx,
pass_num,
pass_name,
&node_path,
disambiguator,
source,
body,
extra_data,
);
}
pub fn dump_enabled<'tcx>(tcx: TyCtxt<'tcx>, pass_name: &str, source: MirSource<'tcx>) -> bool {
let filters = match tcx.sess.opts.debugging_opts.dump_mir {
None => return false,
Some(ref filters) => filters,
};
let node_path = ty::print::with_forced_impl_filename_line(|| {
// see notes on #41697 below
tcx.def_path_str(source.def_id())
});
filters.split('|').any(|or_filter| {
or_filter.split('&').all(|and_filter| {
and_filter == "all" || pass_name.contains(and_filter) || node_path.contains(and_filter)
})
})
}
// #41697 -- we use `with_forced_impl_filename_line()` because
// `def_path_str()` would otherwise trigger `type_of`, and this can
// run while we are already attempting to evaluate `type_of`.
fn dump_matched_mir_node<'tcx, F>(
tcx: TyCtxt<'tcx>,
pass_num: Option<&dyn Display>,
pass_name: &str,
node_path: &str,
disambiguator: &dyn Display,
source: MirSource<'tcx>,
body: &Body<'tcx>,
mut extra_data: F,
) where
F: FnMut(PassWhere, &mut dyn Write) -> io::Result<()>,
{
let _: io::Result<()> = try {
let mut file = create_dump_file(tcx, "mir", pass_num, pass_name, disambiguator, source)?;
writeln!(file, "// MIR for `{}`", node_path)?;
writeln!(file, "// source = {:?}", source)?;
writeln!(file, "// pass_name = {}", pass_name)?;
writeln!(file, "// disambiguator = {}", disambiguator)?;
if let Some(ref layout) = body.generator_layout {
writeln!(file, "// generator_layout = {:?}", layout)?;
}
writeln!(file, "")?;
extra_data(PassWhere::BeforeCFG, &mut file)?;
write_user_type_annotations(body, &mut file)?;
write_mir_fn(tcx, source, body, &mut extra_data, &mut file)?;
extra_data(PassWhere::AfterCFG, &mut file)?;
};
if tcx.sess.opts.debugging_opts.dump_mir_graphviz {
let _: io::Result<()> = try {
let mut file =
create_dump_file(tcx, "dot", pass_num, pass_name, disambiguator, source)?;
write_mir_fn_graphviz(tcx, source.def_id(), body, &mut file)?;
};
}
}
/// Returns the path to the filename where we should dump a given MIR.
/// Also used by other bits of code (e.g., NLL inference) that dump
/// graphviz data or other things.
fn dump_path(
tcx: TyCtxt<'_>,
extension: &str,
pass_num: Option<&dyn Display>,
pass_name: &str,
disambiguator: &dyn Display,
source: MirSource<'tcx>,
) -> PathBuf {
let promotion_id = match source.promoted {
Some(id) => format!("-{:?}", id),
None => String::new(),
};
let pass_num = if tcx.sess.opts.debugging_opts.dump_mir_exclude_pass_number {
String::new()
} else {
match pass_num {
None => ".-------".to_string(),
Some(pass_num) => format!(".{}", pass_num),
}
};
let mut file_path = PathBuf::new();
file_path.push(Path::new(&tcx.sess.opts.debugging_opts.dump_mir_dir));
let item_name = tcx
.def_path(source.def_id())
.to_filename_friendly_no_crate();
// All drop shims have the same DefId, so we have to add the type
// to get unique file names.
let shim_disambiguator = match source.instance {
ty::InstanceDef::DropGlue(_, Some(ty)) => {
// Unfortunately, pretty-printed typed are not very filename-friendly.
// We dome some filtering.
let mut s = ".".to_owned();
s.extend(ty.to_string()
.chars()
.filter_map(|c| match c {
' ' => None,
':' | '<' | '>' => Some('_'),
c => Some(c)
}));
s
}
_ => String::new(),
};
let file_name = format!(
"rustc.{}{}{}{}.{}.{}.{}",
item_name,
shim_disambiguator,
promotion_id,
pass_num,
pass_name,
disambiguator,
extension,
);
file_path.push(&file_name);
file_path
}
/// Attempts to open a file where we should dump a given MIR or other
/// bit of MIR-related data. Used by `mir-dump`, but also by other
/// bits of code (e.g., NLL inference) that dump graphviz data or
/// other things, and hence takes the extension as an argument.
pub(crate) fn create_dump_file(
tcx: TyCtxt<'_>,
extension: &str,
pass_num: Option<&dyn Display>,
pass_name: &str,
disambiguator: &dyn Display,
source: MirSource<'tcx>,
) -> io::Result<io::BufWriter<fs::File>> {
let file_path = dump_path(tcx, extension, pass_num, pass_name, disambiguator, source);
if let Some(parent) = file_path.parent() {
fs::create_dir_all(parent)?;
}
Ok(io::BufWriter::new(fs::File::create(&file_path)?))
}
/// Write out a human-readable textual representation for the given MIR.
pub fn write_mir_pretty<'tcx>(
tcx: TyCtxt<'tcx>,
single: Option<DefId>,
w: &mut dyn Write,
) -> io::Result<()> {
writeln!(
w,
"// WARNING: This output format is intended for human consumers only"
)?;
writeln!(
w,
"// and is subject to change without notice. Knock yourself out."
)?;
let mut first = true;
for def_id in dump_mir_def_ids(tcx, single) {
let body = &tcx.optimized_mir(def_id);
if first {
first = false;
} else {
// Put empty lines between all items
writeln!(w, "")?;
}
write_mir_fn(tcx, MirSource::item(def_id), body, &mut |_, _| Ok(()), w)?;
for (i, body) in tcx.promoted_mir(def_id).iter_enumerated() {
writeln!(w, "")?;
let src = MirSource {
instance: ty::InstanceDef::Item(def_id),
promoted: Some(i),
};
write_mir_fn(tcx, src, body, &mut |_, _| Ok(()), w)?;
}
}
Ok(())
}
pub fn write_mir_fn<'tcx, F>(
tcx: TyCtxt<'tcx>,
src: MirSource<'tcx>,
body: &Body<'tcx>,
extra_data: &mut F,
w: &mut dyn Write,
) -> io::Result<()>
where
F: FnMut(PassWhere, &mut dyn Write) -> io::Result<()>,
{
write_mir_intro(tcx, src, body, w)?;
for block in body.basic_blocks().indices() {
extra_data(PassWhere::BeforeBlock(block), w)?;
write_basic_block(tcx, block, body, extra_data, w)?;
if block.index() + 1 != body.basic_blocks().len() {
writeln!(w, "")?;
}
}
writeln!(w, "}}")?;
Ok(())
}
/// Write out a human-readable textual representation for the given basic block.
pub fn write_basic_block<'tcx, F>(
tcx: TyCtxt<'tcx>,
block: BasicBlock,
body: &Body<'tcx>,
extra_data: &mut F,
w: &mut dyn Write,
) -> io::Result<()>
where
F: FnMut(PassWhere, &mut dyn Write) -> io::Result<()>,
{
let data = &body[block];
// Basic block label at the top.
let cleanup_text = if data.is_cleanup { " (cleanup)" } else { "" };
writeln!(w, "{}{:?}{}: {{", INDENT, block, cleanup_text)?;
// List of statements in the middle.
let mut current_location = Location {
block: block,
statement_index: 0,
};
for statement in &data.statements {
extra_data(PassWhere::BeforeLocation(current_location), w)?;
let indented_body = format!("{0}{0}{1:?};", INDENT, statement);
writeln!(
w,
"{:A$} // {:?}: {}",
indented_body,
current_location,
comment(tcx, statement.source_info),
A = ALIGN,
)?;
write_extra(tcx, w, |visitor| {
visitor.visit_statement(statement, current_location);
})?;
extra_data(PassWhere::AfterLocation(current_location), w)?;
current_location.statement_index += 1;
}
// Terminator at the bottom.
extra_data(PassWhere::BeforeLocation(current_location), w)?;
let indented_terminator = format!("{0}{0}{1:?};", INDENT, data.terminator().kind);
writeln!(
w,
"{:A$} // {:?}: {}",
indented_terminator,
current_location,
comment(tcx, data.terminator().source_info),
A = ALIGN,
)?;
write_extra(tcx, w, |visitor| {
visitor.visit_terminator(data.terminator(), current_location);
})?;
extra_data(PassWhere::AfterLocation(current_location), w)?;
extra_data(PassWhere::AfterTerminator(block), w)?;
writeln!(w, "{}}}", INDENT)
}
/// After we print the main statement, we sometimes dump extra
/// information. There's often a lot of little things "nuzzled up" in
/// a statement.
fn write_extra<'tcx, F>(tcx: TyCtxt<'tcx>, write: &mut dyn Write, mut visit_op: F) -> io::Result<()>
where
F: FnMut(&mut ExtraComments<'tcx>),
{
let mut extra_comments = ExtraComments {
_tcx: tcx,
comments: vec![],
};
visit_op(&mut extra_comments);
for comment in extra_comments.comments {
writeln!(write, "{:A$} // {}", "", comment, A = ALIGN)?;
}
Ok(())
}
struct ExtraComments<'tcx> {
_tcx: TyCtxt<'tcx>, // don't need it now, but bet we will soon
comments: Vec<String>,
}
impl ExtraComments<'tcx> {
fn push(&mut self, lines: &str) {
for line in lines.split('\n') {
self.comments.push(line.to_string());
}
}
}
impl Visitor<'tcx> for ExtraComments<'tcx> {
fn visit_constant(&mut self, constant: &Constant<'tcx>, location: Location) {
self.super_constant(constant, location);
let Constant { span, user_ty, literal } = constant;
self.push("mir::Constant");
self.push(&format!("+ span: {:?}", span));
if let Some(user_ty) = user_ty {
self.push(&format!("+ user_ty: {:?}", user_ty));
}
self.push(&format!("+ literal: {:?}", literal));
}
fn visit_const(&mut self, constant: &&'tcx ty::Const<'tcx>, _: Location) {
self.super_const(constant);
let ty::Const { ty, val, .. } = constant;
self.push("ty::Const");
self.push(&format!("+ ty: {:?}", ty));
self.push(&format!("+ val: {:?}", val));
}
fn visit_rvalue(&mut self, rvalue: &Rvalue<'tcx>, location: Location) {
self.super_rvalue(rvalue, location);
match rvalue {
Rvalue::Aggregate(kind, _) => match **kind {
AggregateKind::Closure(def_id, substs) => {
self.push("closure");
self.push(&format!("+ def_id: {:?}", def_id));
self.push(&format!("+ substs: {:#?}", substs));
}
AggregateKind::Generator(def_id, substs, movability) => {
self.push("generator");
self.push(&format!("+ def_id: {:?}", def_id));
self.push(&format!("+ substs: {:#?}", substs));
self.push(&format!("+ movability: {:?}", movability));
}
AggregateKind::Adt(_, _, _, Some(user_ty), _) => {
self.push("adt");
self.push(&format!("+ user_ty: {:?}", user_ty));
}
_ => {}
},
_ => {}
}
}
}
fn comment(tcx: TyCtxt<'_>, SourceInfo { span, scope }: SourceInfo) -> String {
format!(
"scope {} at {}",
scope.index(),
tcx.sess.source_map().span_to_string(span)
)
}
/// Prints local variables in a scope tree.
fn write_scope_tree(
tcx: TyCtxt<'_>,
body: &Body<'_>,
scope_tree: &FxHashMap<SourceScope, Vec<SourceScope>>,
w: &mut dyn Write,
parent: SourceScope,
depth: usize,
) -> io::Result<()> {
let indent = depth * INDENT.len();
// Local variable types (including the user's name in a comment).
for (local, local_decl) in body.local_decls.iter_enumerated() {
if (1..body.arg_count+1).contains(&local.index()) {
// Skip over argument locals, they're printed in the signature.
continue;
}
if local_decl.source_info.scope != parent {
// Not declared in this scope.
continue;
}
let mut_str = if local_decl.mutability == Mutability::Mut {
"mut "
} else {
""
};
let mut indented_decl = format!(
"{0:1$}let {2}{3:?}: {4:?}",
INDENT,
indent,
mut_str,
local,
local_decl.ty
);
for user_ty in local_decl.user_ty.projections() {
write!(indented_decl, " as {:?}", user_ty).unwrap();
}
indented_decl.push_str(";");
let local_name = if local == RETURN_PLACE {
format!(" return place")
} else if let Some(name) = local_decl.name {
format!(" \"{}\"", name)
} else {
String::new()
};
writeln!(
w,
"{0:1$} //{2} in {3}",
indented_decl,
ALIGN,
local_name,
comment(tcx, local_decl.source_info),
)?;
}
let children = match scope_tree.get(&parent) {
Some(childs) => childs,
None => return Ok(()),
};
for &child in children {
assert_eq!(body.source_scopes[child].parent_scope, Some(parent));
writeln!(w, "{0:1$}scope {2} {{", "", indent, child.index())?;
write_scope_tree(tcx, body, scope_tree, w, child, depth + 1)?;
writeln!(w, "{0:1$}}}", "", depth * INDENT.len())?;
}
Ok(())
}
/// Write out a human-readable textual representation of the MIR's `fn` type and the types of its
/// local variables (both user-defined bindings and compiler temporaries).
pub fn write_mir_intro<'tcx>(
tcx: TyCtxt<'tcx>,
src: MirSource<'tcx>,
body: &Body<'_>,
w: &mut dyn Write,
) -> io::Result<()> {
write_mir_sig(tcx, src, body, w)?;
writeln!(w, "{{")?;
// construct a scope tree and write it out
let mut scope_tree: FxHashMap<SourceScope, Vec<SourceScope>> = Default::default();
for (index, scope_data) in body.source_scopes.iter().enumerate() {
if let Some(parent) = scope_data.parent_scope {
scope_tree
.entry(parent)
.or_default()
.push(SourceScope::new(index));
} else {
// Only the argument scope has no parent, because it's the root.
assert_eq!(index, OUTERMOST_SOURCE_SCOPE.index());
}
}
write_scope_tree(tcx, body, &scope_tree, w, OUTERMOST_SOURCE_SCOPE, 1)?;
// Add an empty line before the first block is printed.
writeln!(w, "")?;
Ok(())
}
fn write_mir_sig(
tcx: TyCtxt<'_>,
src: MirSource<'tcx>,
body: &Body<'_>,
w: &mut dyn Write,
) -> io::Result<()> {
use rustc::hir::def::DefKind;
trace!("write_mir_sig: {:?}", src.instance);
let kind = tcx.def_kind(src.def_id());
let is_function = match kind {
Some(DefKind::Fn)
| Some(DefKind::Method)
| Some(DefKind::Ctor(..)) => true,
_ => tcx.is_closure(src.def_id()),
};
match (kind, src.promoted) {
(_, Some(i)) => write!(w, "{:?} in ", i)?,
(Some(DefKind::Const), _)
| (Some(DefKind::AssocConst), _) => write!(w, "const ")?,
(Some(DefKind::Static), _) =>
write!(w, "static {}", if tcx.is_mutable_static(src.def_id()) { "mut " } else { "" })?,
(_, _) if is_function => write!(w, "fn ")?,
(None, _) => {}, // things like anon const, not an item
_ => bug!("Unexpected def kind {:?}", kind),
}
ty::print::with_forced_impl_filename_line(|| {
// see notes on #41697 elsewhere
write!(w, " {}", tcx.def_path_str(src.def_id()))
})?;
if src.promoted.is_none() && is_function {
write!(w, "(")?;
// fn argument types.
for (i, arg) in body.args_iter().enumerate() {
if i != 0 {
write!(w, ", ")?;
}
write!(w, "{:?}: {}", Place::from(arg), body.local_decls[arg].ty)?;
}
write!(w, ") -> {}", body.return_ty())?;
} else {
assert_eq!(body.arg_count, 0);
write!(w, ": {} =", body.return_ty())?;
}
if let Some(yield_ty) = body.yield_ty {
writeln!(w)?;
writeln!(w, "yields {}", yield_ty)?;
}
write!(w, " ")?;
// Next thing that gets printed is the opening {
Ok(())
}
fn write_user_type_annotations(body: &Body<'_>, w: &mut dyn Write) -> io::Result<()> {
if !body.user_type_annotations.is_empty() {
writeln!(w, "| User Type Annotations")?;
}
for (index, annotation) in body.user_type_annotations.iter_enumerated() {
writeln!(w, "| {:?}: {:?} at {:?}", index.index(), annotation.user_ty, annotation.span)?;
}
if !body.user_type_annotations.is_empty() {
writeln!(w, "|")?;
}
Ok(())
}
pub fn dump_mir_def_ids(tcx: TyCtxt<'_>, single: Option<DefId>) -> Vec<DefId> {
if let Some(i) = single {
vec![i]
} else {
tcx.mir_keys(LOCAL_CRATE).iter().cloned().collect()
}
}