use super::address_transform::AddressTransform;
use super::attr::{clone_die_attributes, FileAttributeContext};
use super::expression::compile_expression;
use super::line_program::clone_line_program;
use super::range_info_builder::RangeInfoBuilder;
use super::refs::{PendingDebugInfoRefs, PendingUnitRefs, UnitRefsMap};
use super::utils::{add_internal_types, append_vmctx_info, get_function_frame_info};
use super::{DebugInputContext, Reader, TransformError};
use crate::debug::ModuleMemoryOffset;
use crate::CompiledFunctions;
use anyhow::{Context, Error};
use cranelift_codegen::ir::Endianness;
use cranelift_codegen::isa::TargetIsa;
use gimli::write;
use gimli::{AttributeValue, DebuggingInformationEntry, Unit};
use std::collections::HashSet;
use wasmtime_environ::DefinedFuncIndex;
struct InheritedAttr<T> {
stack: Vec<(usize, T)>,
}
impl<T> InheritedAttr<T> {
fn new() -> Self {
InheritedAttr { stack: Vec::new() }
}
fn update(&mut self, depth: usize) {
while !self.stack.is_empty() && self.stack.last().unwrap().0 >= depth {
self.stack.pop();
}
}
fn push(&mut self, depth: usize, value: T) {
self.stack.push((depth, value));
}
fn top(&self) -> Option<&T> {
self.stack.last().map(|entry| &entry.1)
}
fn is_empty(&self) -> bool {
self.stack.is_empty()
}
}
fn get_base_type_name<R>(
type_entry: &DebuggingInformationEntry<R>,
unit: &Unit<R, R::Offset>,
context: &DebugInputContext<R>,
) -> Result<String, Error>
where
R: Reader,
{
if let Some(AttributeValue::UnitRef(ref offset)) = type_entry.attr_value(gimli::DW_AT_type)? {
let mut entries = unit.entries_at_offset(*offset)?;
entries.next_entry()?;
if let Some(die) = entries.current() {
if let Some(AttributeValue::DebugStrRef(str_offset)) =
die.attr_value(gimli::DW_AT_name)?
{
return Ok(String::from(
context.debug_str.get_str(str_offset)?.to_string()?,
));
}
match die.tag() {
gimli::DW_TAG_const_type => {
return Ok(format!("const {}", get_base_type_name(die, unit, context)?));
}
gimli::DW_TAG_pointer_type => {
return Ok(format!("{}*", get_base_type_name(die, unit, context)?));
}
gimli::DW_TAG_reference_type => {
return Ok(format!("{}&", get_base_type_name(die, unit, context)?));
}
gimli::DW_TAG_array_type => {
return Ok(format!("{}[]", get_base_type_name(die, unit, context)?));
}
_ => (),
}
}
}
Ok(String::from("??"))
}
enum WebAssemblyPtrKind {
Reference,
Pointer,
}
fn replace_pointer_type<R>(
parent_id: write::UnitEntryId,
kind: WebAssemblyPtrKind,
comp_unit: &mut write::Unit,
wp_die_id: write::UnitEntryId,
pointer_type_entry: &DebuggingInformationEntry<R>,
unit: &Unit<R, R::Offset>,
context: &DebugInputContext<R>,
out_strings: &mut write::StringTable,
pending_die_refs: &mut PendingUnitRefs,
) -> Result<write::UnitEntryId, Error>
where
R: Reader,
{
const WASM_PTR_LEN: u8 = 4;
macro_rules! add_tag {
($parent_id:ident, $tag:expr => $die:ident as $die_id:ident { $($a:path = $v:expr),* }) => {
let $die_id = comp_unit.add($parent_id, $tag);
#[allow(unused_variables)]
let $die = comp_unit.get_mut($die_id);
$( $die.set($a, $v); )*
};
}
let name = match kind {
WebAssemblyPtrKind::Pointer => format!(
"WebAssemblyPtrWrapper<{}>",
get_base_type_name(pointer_type_entry, unit, context)?
),
WebAssemblyPtrKind::Reference => format!(
"WebAssemblyRefWrapper<{}>",
get_base_type_name(pointer_type_entry, unit, context)?
),
};
add_tag!(parent_id, gimli::DW_TAG_structure_type => wrapper_die as wrapper_die_id {
gimli::DW_AT_name = write::AttributeValue::StringRef(out_strings.add(name.as_str())),
gimli::DW_AT_byte_size = write::AttributeValue::Data1(WASM_PTR_LEN)
});
add_tag!(parent_id, gimli::DW_TAG_pointer_type => wrapper_ptr_type as wrapper_ptr_type_id {
gimli::DW_AT_type = write::AttributeValue::UnitRef(wrapper_die_id)
});
let base_type_id = pointer_type_entry.attr_value(gimli::DW_AT_type)?;
add_tag!(parent_id, gimli::DW_TAG_reference_type => ref_type as ref_type_id {});
if let Some(AttributeValue::UnitRef(ref offset)) = base_type_id {
pending_die_refs.insert(ref_type_id, gimli::DW_AT_type, *offset);
}
add_tag!(parent_id, gimli::DW_TAG_pointer_type => ptr_type as ptr_type_id {});
if let Some(AttributeValue::UnitRef(ref offset)) = base_type_id {
pending_die_refs.insert(ptr_type_id, gimli::DW_AT_type, *offset);
}
add_tag!(wrapper_die_id, gimli::DW_TAG_template_type_parameter => t_param_die as t_param_die_id {
gimli::DW_AT_name = write::AttributeValue::StringRef(out_strings.add("T"))
});
if let Some(AttributeValue::UnitRef(ref offset)) = base_type_id {
pending_die_refs.insert(t_param_die_id, gimli::DW_AT_type, *offset);
}
add_tag!(wrapper_die_id, gimli::DW_TAG_member => m_die as m_die_id {
gimli::DW_AT_name = write::AttributeValue::StringRef(out_strings.add("__ptr")),
gimli::DW_AT_type = write::AttributeValue::UnitRef(wp_die_id),
gimli::DW_AT_data_member_location = write::AttributeValue::Data1(0)
});
add_tag!(wrapper_die_id, gimli::DW_TAG_subprogram => deref_op_die as deref_op_die_id {
gimli::DW_AT_linkage_name = write::AttributeValue::StringRef(out_strings.add("resolve_vmctx_memory_ptr")),
gimli::DW_AT_name = write::AttributeValue::StringRef(out_strings.add("ptr")),
gimli::DW_AT_type = write::AttributeValue::UnitRef(ptr_type_id)
});
add_tag!(deref_op_die_id, gimli::DW_TAG_formal_parameter => deref_op_this_param as deref_op_this_param_id {
gimli::DW_AT_type = write::AttributeValue::UnitRef(wrapper_ptr_type_id),
gimli::DW_AT_artificial = write::AttributeValue::Flag(true)
});
add_tag!(wrapper_die_id, gimli::DW_TAG_subprogram => deref_op_die as deref_op_die_id {
gimli::DW_AT_linkage_name = write::AttributeValue::StringRef(out_strings.add("resolve_vmctx_memory_ptr")),
gimli::DW_AT_name = write::AttributeValue::StringRef(out_strings.add("operator*")),
gimli::DW_AT_type = write::AttributeValue::UnitRef(ref_type_id)
});
add_tag!(deref_op_die_id, gimli::DW_TAG_formal_parameter => deref_op_this_param as deref_op_this_param_id {
gimli::DW_AT_type = write::AttributeValue::UnitRef(wrapper_ptr_type_id),
gimli::DW_AT_artificial = write::AttributeValue::Flag(true)
});
add_tag!(wrapper_die_id, gimli::DW_TAG_subprogram => deref_op_die as deref_op_die_id {
gimli::DW_AT_linkage_name = write::AttributeValue::StringRef(out_strings.add("resolve_vmctx_memory_ptr")),
gimli::DW_AT_name = write::AttributeValue::StringRef(out_strings.add("operator->")),
gimli::DW_AT_type = write::AttributeValue::UnitRef(ptr_type_id)
});
add_tag!(deref_op_die_id, gimli::DW_TAG_formal_parameter => deref_op_this_param as deref_op_this_param_id {
gimli::DW_AT_type = write::AttributeValue::UnitRef(wrapper_ptr_type_id),
gimli::DW_AT_artificial = write::AttributeValue::Flag(true)
});
Ok(wrapper_die_id)
}
fn is_dead_code<R: Reader>(entry: &DebuggingInformationEntry<R>) -> bool {
const TOMBSTONE: u64 = u32::MAX as u64;
match entry.attr_value(gimli::DW_AT_low_pc) {
Ok(Some(AttributeValue::Addr(addr))) => addr == TOMBSTONE,
_ => false,
}
}
pub(crate) fn clone_unit<'a, R>(
dwarf: &gimli::Dwarf<R>,
unit: Unit<R, R::Offset>,
context: &DebugInputContext<R>,
addr_tr: &'a AddressTransform,
funcs: &'a CompiledFunctions,
memory_offset: &ModuleMemoryOffset,
out_encoding: gimli::Encoding,
out_units: &mut write::UnitTable,
out_strings: &mut write::StringTable,
translated: &mut HashSet<DefinedFuncIndex>,
isa: &dyn TargetIsa,
) -> Result<Option<(write::UnitId, UnitRefsMap, PendingDebugInfoRefs)>, Error>
where
R: Reader,
{
let mut die_ref_map = UnitRefsMap::new();
let mut pending_die_refs = PendingUnitRefs::new();
let mut pending_di_refs = PendingDebugInfoRefs::new();
let mut stack = Vec::new();
let mut entries = unit.entries();
let (mut comp_unit, unit_id, file_map, file_index_base, cu_low_pc, wp_die_id, vmctx_die_id) =
if let Some((depth_delta, entry)) = entries.next_dfs()? {
assert_eq!(depth_delta, 0);
let (out_line_program, debug_line_offset, file_map, file_index_base) =
clone_line_program(
&unit,
entry,
addr_tr,
out_encoding,
context.debug_str,
context.debug_str_offsets,
context.debug_line_str,
context.debug_line,
out_strings,
)?;
if entry.tag() == gimli::DW_TAG_compile_unit {
let unit_id = out_units.add(write::Unit::new(out_encoding, out_line_program));
let comp_unit = out_units.get_mut(unit_id);
let root_id = comp_unit.root();
die_ref_map.insert(entry.offset(), root_id);
let cu_low_pc = if let Some(AttributeValue::Addr(addr)) =
entry.attr_value(gimli::DW_AT_low_pc)?
{
addr
} else if let Some(AttributeValue::DebugAddrIndex(i)) =
entry.attr_value(gimli::DW_AT_low_pc)?
{
context.debug_addr.get_address(4, unit.addr_base, i)?
} else {
0
};
clone_die_attributes(
dwarf,
&unit,
entry,
context,
addr_tr,
None,
comp_unit,
root_id,
None,
None,
cu_low_pc,
out_strings,
&mut pending_die_refs,
&mut pending_di_refs,
FileAttributeContext::Root(Some(debug_line_offset)),
isa,
)?;
let (wp_die_id, vmctx_die_id) =
add_internal_types(comp_unit, root_id, out_strings, memory_offset);
stack.push(root_id);
(
comp_unit,
unit_id,
file_map,
file_index_base,
cu_low_pc,
wp_die_id,
vmctx_die_id,
)
} else {
return Err(TransformError("Unexpected unit header").into());
}
} else {
return Ok(None); };
let mut skip_at_depth = None;
let mut current_frame_base = InheritedAttr::new();
let mut current_value_range = InheritedAttr::new();
let mut current_scope_ranges = InheritedAttr::new();
while let Some((depth_delta, entry)) = entries.next_dfs()? {
let depth_delta = if let Some((depth, cached)) = skip_at_depth {
let new_depth = depth + depth_delta;
if new_depth > 0 {
skip_at_depth = Some((new_depth, cached));
continue;
}
skip_at_depth = None;
new_depth + cached
} else {
depth_delta
};
if !context
.reachable
.contains(&entry.offset().to_unit_section_offset(&unit))
|| is_dead_code(&entry)
{
skip_at_depth = Some((0, depth_delta));
continue;
}
let new_stack_len = stack.len().wrapping_add(depth_delta as usize);
current_frame_base.update(new_stack_len);
current_scope_ranges.update(new_stack_len);
current_value_range.update(new_stack_len);
let range_builder = if entry.tag() == gimli::DW_TAG_subprogram {
let range_builder = RangeInfoBuilder::from_subprogram_die(
dwarf, &unit, entry, context, addr_tr, cu_low_pc,
)?;
if let RangeInfoBuilder::Function(func_index) = range_builder {
if let Some(frame_info) = get_function_frame_info(memory_offset, funcs, func_index)
{
current_value_range.push(new_stack_len, frame_info);
}
translated.insert(func_index);
current_scope_ranges.push(new_stack_len, range_builder.get_ranges(addr_tr));
Some(range_builder)
} else {
None
}
} else {
let high_pc = entry.attr_value(gimli::DW_AT_high_pc)?;
let ranges = entry.attr_value(gimli::DW_AT_ranges)?;
if high_pc.is_some() || ranges.is_some() {
let range_builder =
RangeInfoBuilder::from(dwarf, &unit, entry, context, cu_low_pc)?;
current_scope_ranges.push(new_stack_len, range_builder.get_ranges(addr_tr));
Some(range_builder)
} else {
None
}
};
if depth_delta <= 0 {
for _ in depth_delta..1 {
stack.pop();
}
} else {
assert_eq!(depth_delta, 1);
}
if let Some(AttributeValue::Exprloc(expr)) = entry.attr_value(gimli::DW_AT_frame_base)? {
if let Some(expr) = compile_expression(&expr, unit.encoding(), None)? {
current_frame_base.push(new_stack_len, expr);
}
}
let parent = stack.last().unwrap();
if entry.tag() == gimli::DW_TAG_pointer_type || entry.tag() == gimli::DW_TAG_reference_type
{
let pointer_kind = match entry.tag() {
gimli::DW_TAG_pointer_type => WebAssemblyPtrKind::Pointer,
gimli::DW_TAG_reference_type => WebAssemblyPtrKind::Reference,
_ => panic!(),
};
let die_id = replace_pointer_type(
*parent,
pointer_kind,
comp_unit,
wp_die_id,
entry,
&unit,
context,
out_strings,
&mut pending_die_refs,
)?;
stack.push(die_id);
assert_eq!(stack.len(), new_stack_len);
die_ref_map.insert(entry.offset(), die_id);
continue;
}
let die_id = comp_unit.add(*parent, entry.tag());
stack.push(die_id);
assert_eq!(stack.len(), new_stack_len);
die_ref_map.insert(entry.offset(), die_id);
clone_die_attributes(
dwarf,
&unit,
entry,
context,
addr_tr,
current_value_range.top(),
&mut comp_unit,
die_id,
range_builder,
current_scope_ranges.top(),
cu_low_pc,
out_strings,
&mut pending_die_refs,
&mut pending_di_refs,
FileAttributeContext::Children {
file_map: &file_map,
file_index_base,
frame_base: current_frame_base.top(),
},
isa,
)?;
if entry.tag() == gimli::DW_TAG_base_type && isa.endianness() == Endianness::Big {
let current_scope = comp_unit.get_mut(die_id);
current_scope.set(
gimli::DW_AT_endianity,
write::AttributeValue::Endianity(gimli::DW_END_little),
);
}
if entry.tag() == gimli::DW_TAG_subprogram && !current_scope_ranges.is_empty() {
append_vmctx_info(
comp_unit,
die_id,
vmctx_die_id,
addr_tr,
current_value_range.top(),
current_scope_ranges.top().context("range")?,
out_strings,
isa,
)?;
}
}
die_ref_map.patch(pending_die_refs, comp_unit);
Ok(Some((unit_id, die_ref_map, pending_di_refs)))
}