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use crate::errors::{
DuplicateValuesFor, PathMustEndInFilename, RequiresAnArgument, UnknownFormatter,
};
use crate::framework::BitSetExt;
use std::ffi::OsString;
use std::path::PathBuf;
use rustc_ast as ast;
use rustc_data_structures::work_queue::WorkQueue;
use rustc_graphviz as dot;
use rustc_hir::def_id::DefId;
use rustc_index::bit_set::BitSet;
use rustc_index::vec::{Idx, IndexVec};
use rustc_middle::mir::{self, traversal, BasicBlock};
use rustc_middle::mir::{create_dump_file, dump_enabled};
use rustc_middle::ty::TyCtxt;
use rustc_span::symbol::{sym, Symbol};
use super::fmt::DebugWithContext;
use super::graphviz;
use super::{
visit_results, Analysis, Direction, GenKill, GenKillAnalysis, GenKillSet, JoinSemiLattice,
ResultsCursor, ResultsVisitor,
};
pub struct Results<'tcx, A>
where
A: Analysis<'tcx>,
{
pub analysis: A,
pub(super) entry_sets: IndexVec<BasicBlock, A::Domain>,
}
impl<'tcx, A> Results<'tcx, A>
where
A: Analysis<'tcx>,
{
pub fn into_results_cursor<'mir>(
self,
body: &'mir mir::Body<'tcx>,
) -> ResultsCursor<'mir, 'tcx, A> {
ResultsCursor::new(body, self)
}
pub fn entry_set_for_block(&self, block: BasicBlock) -> &A::Domain {
&self.entry_sets[block]
}
pub fn visit_with<'mir>(
&self,
body: &'mir mir::Body<'tcx>,
blocks: impl IntoIterator<Item = BasicBlock>,
vis: &mut impl ResultsVisitor<'mir, 'tcx, FlowState = A::Domain>,
) {
visit_results(body, blocks, self, vis)
}
pub fn visit_reachable_with<'mir>(
&self,
body: &'mir mir::Body<'tcx>,
vis: &mut impl ResultsVisitor<'mir, 'tcx, FlowState = A::Domain>,
) {
let blocks = mir::traversal::reachable(body);
visit_results(body, blocks.map(|(bb, _)| bb), self, vis)
}
}
pub struct Engine<'a, 'tcx, A>
where
A: Analysis<'tcx>,
{
tcx: TyCtxt<'tcx>,
body: &'a mir::Body<'tcx>,
dead_unwinds: Option<&'a BitSet<BasicBlock>>,
entry_sets: IndexVec<BasicBlock, A::Domain>,
pass_name: Option<&'static str>,
analysis: A,
apply_trans_for_block: Option<Box<dyn Fn(BasicBlock, &mut A::Domain)>>,
}
impl<'a, 'tcx, A, D, T> Engine<'a, 'tcx, A>
where
A: GenKillAnalysis<'tcx, Idx = T, Domain = D>,
D: Clone + JoinSemiLattice + GenKill<T> + BitSetExt<T>,
T: Idx,
{
pub fn new_gen_kill(tcx: TyCtxt<'tcx>, body: &'a mir::Body<'tcx>, analysis: A) -> Self {
if !body.basic_blocks.is_cfg_cyclic() {
return Self::new(tcx, body, analysis, None);
}
let identity = GenKillSet::identity(analysis.bottom_value(body).domain_size());
let mut trans_for_block = IndexVec::from_elem(identity, &body.basic_blocks);
for (block, block_data) in body.basic_blocks.iter_enumerated() {
let trans = &mut trans_for_block[block];
A::Direction::gen_kill_effects_in_block(&analysis, trans, block, block_data);
}
let apply_trans = Box::new(move |bb: BasicBlock, state: &mut A::Domain| {
trans_for_block[bb].apply(state);
});
Self::new(tcx, body, analysis, Some(apply_trans as Box<_>))
}
}
impl<'a, 'tcx, A, D> Engine<'a, 'tcx, A>
where
A: Analysis<'tcx, Domain = D>,
D: Clone + JoinSemiLattice,
{
pub fn new_generic(tcx: TyCtxt<'tcx>, body: &'a mir::Body<'tcx>, analysis: A) -> Self {
Self::new(tcx, body, analysis, None)
}
fn new(
tcx: TyCtxt<'tcx>,
body: &'a mir::Body<'tcx>,
analysis: A,
apply_trans_for_block: Option<Box<dyn Fn(BasicBlock, &mut A::Domain)>>,
) -> Self {
let bottom_value = analysis.bottom_value(body);
let mut entry_sets = IndexVec::from_elem(bottom_value.clone(), &body.basic_blocks);
analysis.initialize_start_block(body, &mut entry_sets[mir::START_BLOCK]);
if A::Direction::IS_BACKWARD && entry_sets[mir::START_BLOCK] != bottom_value {
bug!("`initialize_start_block` is not yet supported for backward dataflow analyses");
}
Engine {
analysis,
tcx,
body,
dead_unwinds: None,
pass_name: None,
entry_sets,
apply_trans_for_block,
}
}
pub fn dead_unwinds(mut self, dead_unwinds: &'a BitSet<BasicBlock>) -> Self {
self.dead_unwinds = Some(dead_unwinds);
self
}
pub fn pass_name(mut self, name: &'static str) -> Self {
self.pass_name = Some(name);
self
}
pub fn iterate_to_fixpoint(self) -> Results<'tcx, A>
where
A::Domain: DebugWithContext<A>,
{
let Engine {
analysis,
body,
dead_unwinds,
mut entry_sets,
tcx,
apply_trans_for_block,
pass_name,
..
} = self;
let mut dirty_queue: WorkQueue<BasicBlock> = WorkQueue::with_none(body.basic_blocks.len());
if A::Direction::IS_FORWARD {
for (bb, _) in traversal::reverse_postorder(body) {
dirty_queue.insert(bb);
}
} else {
for (bb, _) in traversal::postorder(body) {
dirty_queue.insert(bb);
}
}
let mut state = analysis.bottom_value(body);
while let Some(bb) = dirty_queue.pop() {
let bb_data = &body[bb];
state.clone_from(&entry_sets[bb]);
match &apply_trans_for_block {
Some(apply) => apply(bb, &mut state),
None => A::Direction::apply_effects_in_block(&analysis, &mut state, bb, bb_data),
}
A::Direction::join_state_into_successors_of(
&analysis,
tcx,
body,
dead_unwinds,
&mut state,
(bb, bb_data),
|target: BasicBlock, state: &A::Domain| {
let set_changed = entry_sets[target].join(state);
if set_changed {
dirty_queue.insert(target);
}
},
);
}
let results = Results { analysis, entry_sets };
let res = write_graphviz_results(tcx, &body, &results, pass_name);
if let Err(e) = res {
error!("Failed to write graphviz dataflow results: {}", e);
}
results
}
}
fn write_graphviz_results<'tcx, A>(
tcx: TyCtxt<'tcx>,
body: &mir::Body<'tcx>,
results: &Results<'tcx, A>,
pass_name: Option<&'static str>,
) -> std::io::Result<()>
where
A: Analysis<'tcx>,
A::Domain: DebugWithContext<A>,
{
use std::fs;
use std::io::{self, Write};
let def_id = body.source.def_id();
let Ok(attrs) = RustcMirAttrs::parse(tcx, def_id) else {
return Ok(());
};
let mut file = match attrs.output_path(A::NAME) {
Some(path) => {
debug!("printing dataflow results for {:?} to {}", def_id, path.display());
if let Some(parent) = path.parent() {
fs::create_dir_all(parent)?;
}
io::BufWriter::new(fs::File::create(&path)?)
}
None if tcx.sess.opts.unstable_opts.dump_mir_dataflow
&& dump_enabled(tcx, A::NAME, def_id) =>
{
create_dump_file(
tcx,
".dot",
None,
A::NAME,
&pass_name.unwrap_or("-----"),
body.source,
)?
}
_ => return Ok(()),
};
let style = match attrs.formatter {
Some(sym::two_phase) => graphviz::OutputStyle::BeforeAndAfter,
_ => graphviz::OutputStyle::AfterOnly,
};
let mut buf = Vec::new();
let graphviz = graphviz::Formatter::new(body, results, style);
let mut render_opts =
vec![dot::RenderOption::Fontname(tcx.sess.opts.unstable_opts.graphviz_font.clone())];
if tcx.sess.opts.unstable_opts.graphviz_dark_mode {
render_opts.push(dot::RenderOption::DarkTheme);
}
dot::render_opts(&graphviz, &mut buf, &render_opts)?;
file.write_all(&buf)?;
Ok(())
}
#[derive(Default)]
struct RustcMirAttrs {
basename_and_suffix: Option<PathBuf>,
formatter: Option<Symbol>,
}
impl RustcMirAttrs {
fn parse(tcx: TyCtxt<'_>, def_id: DefId) -> Result<Self, ()> {
let mut result = Ok(());
let mut ret = RustcMirAttrs::default();
let rustc_mir_attrs = tcx
.get_attrs(def_id, sym::rustc_mir)
.flat_map(|attr| attr.meta_item_list().into_iter().flat_map(|v| v.into_iter()));
for attr in rustc_mir_attrs {
let attr_result = if attr.has_name(sym::borrowck_graphviz_postflow) {
Self::set_field(&mut ret.basename_and_suffix, tcx, &attr, |s| {
let path = PathBuf::from(s.to_string());
match path.file_name() {
Some(_) => Ok(path),
None => {
tcx.sess.emit_err(PathMustEndInFilename { span: attr.span() });
Err(())
}
}
})
} else if attr.has_name(sym::borrowck_graphviz_format) {
Self::set_field(&mut ret.formatter, tcx, &attr, |s| match s {
sym::gen_kill | sym::two_phase => Ok(s),
_ => {
tcx.sess.emit_err(UnknownFormatter { span: attr.span() });
Err(())
}
})
} else {
Ok(())
};
result = result.and(attr_result);
}
result.map(|()| ret)
}
fn set_field<T>(
field: &mut Option<T>,
tcx: TyCtxt<'_>,
attr: &ast::NestedMetaItem,
mapper: impl FnOnce(Symbol) -> Result<T, ()>,
) -> Result<(), ()> {
if field.is_some() {
tcx.sess.emit_err(DuplicateValuesFor { span: attr.span(), name: attr.name_or_empty() });
return Err(());
}
if let Some(s) = attr.value_str() {
*field = Some(mapper(s)?);
Ok(())
} else {
tcx.sess.emit_err(RequiresAnArgument { span: attr.span(), name: attr.name_or_empty() });
Err(())
}
}
fn output_path(&self, analysis_name: &str) -> Option<PathBuf> {
let mut ret = self.basename_and_suffix.as_ref().cloned()?;
let suffix = ret.file_name().unwrap(); let mut file_name: OsString = analysis_name.into();
file_name.push("_");
file_name.push(suffix);
ret.set_file_name(file_name);
Some(ret)
}
}