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Fix value label ranges resolution (#1572)

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There was a bug how value labels were resolved, which caused some DWARF expressions not be transformed, e.g. those are in the registers.

*    Implements FIXME in expression.rs
*    Move TargetIsa from CompiledExpression structure
*    Fix expression format for GDB
*    Add tests for parsing
*    Proper logic in ValueLabelRangesBuilder::process_label
*    Tests for ValueLabelRangesBuilder
*    Refactor build_with_locals to return Iterator instead of Vec<_>
*    Misc comments and magical numbers
This commit is contained in:
Yury Delendik
2020-04-30 08:07:55 -05:00
committed by GitHub
parent b7cfd39b53
commit 1873c0ae46
8 changed files with 598 additions and 331 deletions
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79
crates/debug/src/transform/attr.rs
View File

@@ -13,11 +13,11 @@ use wasmtime_environ::isa::TargetIsa;
#[derive(Debug)]
pub(crate) enum FileAttributeContext<'a> {
Root(Option<DebugLineOffset>),
Children(
&'a Vec<write::FileId>,
u64,
Option<&'a CompiledExpression<'a>>,
),
Children {
file_map: &'a [write::FileId],
file_index_base: u64,
frame_base: Option<&'a CompiledExpression>,
},
}
fn is_exprloc_to_loclist_allowed(attr_name: gimli::constants::DwAt) -> bool {
@@ -55,8 +55,6 @@ pub(crate) fn clone_die_attributes<'a, R>(
where
R: Reader,
{
let _tag = &entry.tag();
let endian = gimli::RunTimeEndian::Little;
let unit_encoding = unit.encoding();
let range_info = if let Some(subprogram_range_builder) = subprogram_range_builder {
@@ -116,7 +114,12 @@ where
}
}
AttributeValue::FileIndex(i) => {
if let FileAttributeContext::Children(file_map, file_index_base, _) = file_context {
if let FileAttributeContext::Children {
file_map,
file_index_base,
..
} = file_context
{
write::AttributeValue::FileIndex(Some(file_map[(i - file_index_base) as usize]))
} else {
return Err(TransformError("unexpected file index attribute").into());
@@ -150,34 +153,41 @@ where
unit.addr_base,
)?;
let frame_base =
if let FileAttributeContext::Children(_, _, frame_base) = file_context {
if let FileAttributeContext::Children { frame_base, .. } = file_context {
frame_base
} else {
None
};
let mut result = None;
let mut result: Option<Vec<_>> = None;
while let Some(loc) = locs.next()? {
if let Some(expr) =
compile_expression(&loc.data, unit_encoding, frame_base, isa)?
{
if result.is_none() {
result = Some(Vec::new());
}
for (start, len, expr) in expr.build_with_locals(
&[(loc.range.begin, loc.range.end)],
addr_tr,
frame_info,
endian,
)? {
if len == 0 {
if let Some(expr) = compile_expression(&loc.data, unit_encoding, frame_base)? {
let chunk = expr
.build_with_locals(
&[(loc.range.begin, loc.range.end)],
addr_tr,
frame_info,
isa,
)
.filter(|i| {
// Ignore empty range
continue;
}
result.as_mut().unwrap().push(write::Location::StartLength {
begin: start,
length: len,
data: expr,
});
if let Ok((_, 0, _)) = i {
false
} else {
true
}
})
.map(|i| {
i.map(|(start, len, expr)| write::Location::StartLength {
begin: start,
length: len,
data: expr,
})
})
.collect::<Result<Vec<_>, _>>()?;
match &mut result {
Some(r) => r.extend(chunk),
x @ None => *x = Some(chunk),
}
} else {
// FIXME _expr contains invalid expression
@@ -192,12 +202,12 @@ where
}
AttributeValue::Exprloc(ref expr) => {
let frame_base =
if let FileAttributeContext::Children(_, _, frame_base) = file_context {
if let FileAttributeContext::Children { frame_base, .. } = file_context {
frame_base
} else {
None
};
if let Some(expr) = compile_expression(expr, unit_encoding, frame_base, isa)? {
if let Some(expr) = compile_expression(expr, unit_encoding, frame_base)? {
if expr.is_simple() {
if let Some(expr) = expr.build() {
write::AttributeValue::Exprloc(expr)
@@ -207,8 +217,9 @@ where
} else {
// Conversion to loclist is required.
if let Some(scope_ranges) = scope_ranges {
let exprs =
expr.build_with_locals(scope_ranges, addr_tr, frame_info, endian)?;
let exprs = expr
.build_with_locals(scope_ranges, addr_tr, frame_info, isa)
.collect::<Result<Vec<_>, _>>()?;
if exprs.is_empty() {
continue;
}