Implement references VarDebugInfo.

This commit is contained in:
Camille GILLOT 2023-05-07 15:39:47 +00:00
parent 1c36f50b3e
commit 2ec0071913
20 changed files with 439 additions and 361 deletions

View file

@ -41,6 +41,9 @@ pub struct PerLocalVarDebugInfo<'tcx, D> {
/// `.place.projection` from `mir::VarDebugInfo`.
pub projection: &'tcx ty::List<mir::PlaceElem<'tcx>>,
/// `references` from `mir::VarDebugInfo`.
pub references: u8,
}
#[derive(Clone, Copy, Debug)]
@ -293,6 +296,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
dbg_var,
fragment: None,
projection: ty::List::empty(),
references: 0,
})
}
} else {
@ -366,14 +370,15 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
&self,
bx: &mut Bx,
local: mir::Local,
base: PlaceRef<'tcx, Bx::Value>,
mut base: PlaceRef<'tcx, Bx::Value>,
var: PerLocalVarDebugInfo<'tcx, Bx::DIVariable>,
) {
let Some(dbg_var) = var.dbg_var else { return };
let Some(dbg_loc) = self.dbg_loc(var.source_info) else { return };
let DebugInfoOffset { direct_offset, indirect_offsets, result: _ } =
let DebugInfoOffset { mut direct_offset, indirect_offsets, result: _ } =
calculate_debuginfo_offset(bx, local, &var, base.layout);
let mut indirect_offsets = &indirect_offsets[..];
// When targeting MSVC, create extra allocas for arguments instead of pointing multiple
// dbg_var_addr() calls into the same alloca with offsets. MSVC uses CodeView records
@ -387,28 +392,44 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
// LLVM can handle simple things but anything more complex than just a direct
// offset or one indirect offset of 0 is too complex for it to generate CV records
// correctly.
&& (direct_offset != Size::ZERO || !matches!(&indirect_offsets[..], [Size::ZERO] | []));
if should_create_individual_allocas {
let DebugInfoOffset { direct_offset: _, indirect_offsets: _, result: place } =
calculate_debuginfo_offset(bx, local, &var, base);
&& (direct_offset != Size::ZERO || !matches!(indirect_offsets, [Size::ZERO] | []));
let create_alloca = |bx: &mut Bx, place: PlaceRef<'tcx, Bx::Value>, refcount| {
// Create a variable which will be a pointer to the actual value
let ptr_ty = bx
.tcx()
.mk_ptr(ty::TypeAndMut { mutbl: mir::Mutability::Mut, ty: place.layout.ty });
let ptr_layout = bx.layout_of(ptr_ty);
let alloca = PlaceRef::alloca(bx, ptr_layout);
bx.set_var_name(alloca.llval, &(var.name.to_string() + ".dbg.spill"));
bx.set_var_name(alloca.llval, &format!("{}.ref{}.dbg.spill", var.name, refcount));
// Write the pointer to the variable
bx.store(place.llval, alloca.llval, alloca.align);
// Point the debug info to `*alloca` for the current variable
bx.dbg_var_addr(dbg_var, dbg_loc, alloca.llval, Size::ZERO, &[Size::ZERO], None);
} else {
bx.dbg_var_addr(dbg_var, dbg_loc, base.llval, direct_offset, &indirect_offsets, None);
alloca
};
if var.references > 0 {
base = calculate_debuginfo_offset(bx, local, &var, base).result;
// Point the debug info to `&...&base == alloca` for the current variable
for refcount in 0..var.references {
base = create_alloca(bx, base, refcount);
}
direct_offset = Size::ZERO;
indirect_offsets = &[];
} else if should_create_individual_allocas {
let place = calculate_debuginfo_offset(bx, local, &var, base).result;
// Point the debug info to `*alloca` for the current variable
base = create_alloca(bx, place, 0);
direct_offset = Size::ZERO;
indirect_offsets = &[Size::ZERO];
}
bx.dbg_var_addr(dbg_var, dbg_loc, base.llval, direct_offset, indirect_offsets, None);
}
pub fn debug_introduce_locals(&self, bx: &mut Bx) {
@ -441,7 +462,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
};
let dbg_var = dbg_scope_and_span.map(|(dbg_scope, _, span)| {
let (var_ty, var_kind) = match var.value {
let (mut var_ty, var_kind) = match var.value {
mir::VarDebugInfoContents::Place(place) => {
let var_ty = self.monomorphized_place_ty(place.as_ref());
let var_kind = if let Some(arg_index) = var.argument_index
@ -478,6 +499,11 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
}
};
for _ in 0..var.references {
var_ty =
bx.tcx().mk_ptr(ty::TypeAndMut { mutbl: mir::Mutability::Mut, ty: var_ty });
}
self.cx.create_dbg_var(var.name, var_ty, dbg_scope, var_kind, span)
});
@ -489,6 +515,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
dbg_var,
fragment: None,
projection: place.projection,
references: var.references,
});
}
mir::VarDebugInfoContents::Const(c) => {
@ -542,6 +569,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
Some(fragment_start..fragment_start + fragment_layout.size)
},
projection: place.projection,
references: var.references,
});
}
}

View file

@ -448,7 +448,15 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
};
match debuginfo.value {
VarDebugInfoContents::Const(_) => {}
VarDebugInfoContents::Place(place) => check_place(place),
VarDebugInfoContents::Place(place) => {
check_place(place);
if debuginfo.references != 0 && place.projection.last() == Some(&PlaceElem::Deref) {
self.fail(
START_BLOCK.start_location(),
format!("debuginfo {:?}, has both ref and deref", debuginfo),
);
}
}
VarDebugInfoContents::Composite { ty, ref fragments } => {
for f in fragments {
check_place(f.contents);

View file

@ -1111,6 +1111,10 @@ pub struct VarDebugInfo<'tcx> {
/// originated from (starting from 1). Note, if MIR inlining is enabled, then this is the
/// argument number in the original function before it was inlined.
pub argument_index: Option<u16>,
/// The data represents `name` dereferenced `references` times,
/// and not the direct value.
pub references: u8,
}
///////////////////////////////////////////////////////////////////////////
@ -1639,18 +1643,7 @@ impl<'tcx> Place<'tcx> {
return self;
}
let mut v: Vec<PlaceElem<'tcx>>;
let new_projections = if self.projection.is_empty() {
more_projections
} else {
v = Vec::with_capacity(self.projection.len() + more_projections.len());
v.extend(self.projection);
v.extend(more_projections);
&v
};
Place { local: self.local, projection: tcx.mk_place_elems(new_projections) }
self.as_ref().project_deeper(more_projections, tcx)
}
}
@ -1721,6 +1714,27 @@ impl<'tcx> PlaceRef<'tcx> {
(base, *proj)
})
}
/// Generates a new place by appending `more_projections` to the existing ones
/// and interning the result.
pub fn project_deeper(
self,
more_projections: &[PlaceElem<'tcx>],
tcx: TyCtxt<'tcx>,
) -> Place<'tcx> {
let mut v: Vec<PlaceElem<'tcx>>;
let new_projections = if self.projection.is_empty() {
more_projections
} else {
v = Vec::with_capacity(self.projection.len() + more_projections.len());
v.extend(self.projection);
v.extend(more_projections);
&v
};
Place { local: self.local, projection: tcx.mk_place_elems(new_projections) }
}
}
impl Debug for Place<'_> {

View file

@ -551,8 +551,13 @@ fn write_scope_tree(
}
let indented_debug_info = format!(
"{0:1$}debug {2} => {3:?};",
INDENT, indent, var_debug_info.name, var_debug_info.value,
"{0:1$}debug {2} => {3:&<4$}{5:?};",
INDENT,
indent,
var_debug_info.name,
"",
var_debug_info.references as usize,
var_debug_info.value,
);
writeln!(

View file

@ -842,6 +842,7 @@ macro_rules! make_mir_visitor {
source_info,
value,
argument_index: _,
references: _,
} = var_debug_info;
self.visit_source_info(source_info);

View file

@ -204,6 +204,7 @@ CloneLiftImpls! {
(),
bool,
usize,
u8,
u16,
u32,
u64,

View file

@ -2241,6 +2241,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
self.var_debug_info.push(VarDebugInfo {
name,
source_info: debug_source_info,
references: 0,
value: VarDebugInfoContents::Place(for_arm_body.into()),
argument_index: None,
});
@ -2260,6 +2261,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
self.var_debug_info.push(VarDebugInfo {
name,
source_info: debug_source_info,
references: 0,
value: VarDebugInfoContents::Place(ref_for_guard.into()),
argument_index: None,
});

View file

@ -798,6 +798,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
};
self.var_debug_info.push(VarDebugInfo {
name,
references: 0,
source_info: SourceInfo::outermost(captured_place.var_ident.span),
value: VarDebugInfoContents::Place(use_place),
argument_index: None,
@ -828,6 +829,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
self.var_debug_info.push(VarDebugInfo {
name,
source_info,
references: 0,
value: VarDebugInfoContents::Place(arg_local.into()),
argument_index: Some(argument_index as u16 + 1),
});

View file

@ -263,6 +263,7 @@ fn compute_replacement<'tcx>(
targets,
storage_to_remove,
allowed_replacements,
fully_replacable_locals,
any_replacement: false,
};
@ -343,6 +344,7 @@ struct Replacer<'tcx> {
storage_to_remove: BitSet<Local>,
allowed_replacements: FxHashSet<(Local, Location)>,
any_replacement: bool,
fully_replacable_locals: BitSet<Local>,
}
impl<'tcx> MutVisitor<'tcx> for Replacer<'tcx> {
@ -350,6 +352,23 @@ impl<'tcx> MutVisitor<'tcx> for Replacer<'tcx> {
self.tcx
}
fn visit_var_debug_info(&mut self, debuginfo: &mut VarDebugInfo<'tcx>) {
if let VarDebugInfoContents::Place(ref mut place) = debuginfo.value
&& place.projection.is_empty()
&& let Value::Pointer(target, _) = self.targets[place.local]
&& target.projection.iter().all(|p| p.can_use_in_debuginfo())
{
if let Some((&PlaceElem::Deref, rest)) = target.projection.split_last() {
*place = Place::from(target.local).project_deeper(rest, self.tcx);
self.any_replacement = true;
} else if self.fully_replacable_locals.contains(place.local) {
debuginfo.references += 1;
*place = target;
self.any_replacement = true;
}
}
}
fn visit_place(&mut self, place: &mut Place<'tcx>, ctxt: PlaceContext, loc: Location) {
if place.projection.first() != Some(&PlaceElem::Deref) {
return;

View file

@ -21,6 +21,7 @@ TrivialTypeTraversalImpls! {
(),
bool,
usize,
u8,
u16,
u32,
u64,