language-servers/roc
1
0
Fork 0
mirror of https://github.com/roc-lang/roc.git synced 2025-08-03 19:58:18 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 6

Merge pull request #4507 from roc-lang/alias-analysis-rc-recursion

Browse source 
fix stack overflow in alias analysis
This commit is contained in:
Ayaz 2022-11-12 12:54:06 -06:00 • committed by GitHub
commit b907f01f1f
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
3 changed files with 67 additions and 39 deletions
Download patch file Download diff file Expand all files Collapse all files

82
crates/compiler/alias_analysis/src/lib.rs
View file

@ -441,6 +441,36 @@ struct Env<'a> {
type_names: MutSet<UnionLayout<'a>>,
}
fn apply_refcount_operation<'a>(
builder: &mut FuncDefBuilder,
env: &mut Env<'a>,
block: BlockId,
modify_rc: &ModifyRc,
) -> Result<()> {
match modify_rc {
ModifyRc::Inc(symbol, _) => {
let argument = env.symbols[symbol];
// a recursive touch is never worse for optimizations than a normal touch
// and a bit more permissive in its type
builder.add_recursive_touch(block, argument)?;
}
ModifyRc::Dec(symbol) => {
let argument = env.symbols[symbol];
builder.add_recursive_touch(block, argument)?;
}
ModifyRc::DecRef(symbol) => {
let argument = env.symbols[symbol];
builder.add_recursive_touch(block, argument)?;
}
};
Ok(())
}
fn stmt_spec<'a>(
builder: &mut FuncDefBuilder,
interner: &STLayoutInterner<'a>,
@ -458,12 +488,25 @@ fn stmt_spec<'a>(
let mut queue = vec![symbol];
while let Let(symbol, expr, expr_layout, c) = continuation {
let value_id = expr_spec(builder, interner, env, block, expr_layout, expr)?;
env.symbols.insert(*symbol, value_id);
loop {
match continuation {
Let(symbol, expr, expr_layout, c) => {
let value_id = expr_spec(builder, interner, env, block, expr_layout, expr)?;
env.symbols.insert(*symbol, value_id);
queue.push(symbol);
continuation = c;
queue.push(symbol);
continuation = c;
}
Refcounting(modify_rc, c) => {
// in practice it is common to see a chain of `Let`s interspersed with
// Inc/Dec. For e.g. the False interpreter, this caused stack overflows.
// so we handle RC operations here to limit recursion depth
apply_refcount_operation(builder, env, block, modify_rc)?;
continuation = c;
}
_ => break,
}
}
let result = stmt_spec(builder, interner, env, block, layout, continuation)?;
@ -499,32 +542,11 @@ fn stmt_spec<'a>(
Expect { remainder, .. } => stmt_spec(builder, interner, env, block, layout, remainder),
ExpectFx { remainder, .. } => stmt_spec(builder, interner, env, block, layout, remainder),
Ret(symbol) => Ok(env.symbols[symbol]),
Refcounting(modify_rc, continuation) => match modify_rc {
ModifyRc::Inc(symbol, _) => {
let argument = env.symbols[symbol];
Refcounting(modify_rc, continuation) => {
apply_refcount_operation(builder, env, block, modify_rc)?;
// a recursive touch is never worse for optimizations than a normal touch
// and a bit more permissive in its type
builder.add_recursive_touch(block, argument)?;
stmt_spec(builder, interner, env, block, layout, continuation)
}
ModifyRc::Dec(symbol) => {
let argument = env.symbols[symbol];
builder.add_recursive_touch(block, argument)?;
stmt_spec(builder, interner, env, block, layout, continuation)
}
ModifyRc::DecRef(symbol) => {
let argument = env.symbols[symbol];
builder.add_recursive_touch(block, argument)?;
stmt_spec(builder, interner, env, block, layout, continuation)
}
},
stmt_spec(builder, interner, env, block, layout, continuation)
}
Join {
id,
parameters,