bjoernager/rust
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[WIP] Set local DW_AT_location

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This commit is contained in:
bjorn3 2019-11-11 21:43:57 +01:00
parent 21f0dfd014
commit 3fed880057
1 changed files with 122 additions and 6 deletions
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128
src/debuginfo.rs
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@ -6,11 +6,15 @@ use std::marker::PhantomData;
use syntax::source_map::FileName;
use cranelift::codegen::ir::{StackSlots, ValueLoc};
use cranelift::codegen::isa::RegUnit;
use gimli::write::{
Address, AttributeValue, DwarfUnit, EndianVec, FileId, LineProgram, LineString,
LineStringTable, Range, RangeList, Result, Sections, UnitEntryId, Writer,
self, Address, AttributeValue, DwarfUnit, EndianVec, Expression, FileId, LineProgram,
LineString, LineStringTable, Location, LocationList, Range, RangeList, Result, Sections,
UnitEntryId, Writer,
};
use gimli::{Encoding, Format, LineEncoding, RunTimeEndian, SectionId};
use gimli::{Encoding, Format, LineEncoding, Register, RunTimeEndian, SectionId, X86_64};
fn target_endian(tcx: TyCtxt) -> RunTimeEndian {
use rustc::ty::layout::Endian;
@ -380,9 +384,9 @@ impl<'a, 'tcx> FunctionDebugContext<'a, 'tcx> {
.chain(
value_loc_ranges
.iter()
.map(|val_loc_range| Range::OffsetPair {
begin: u64::from(val_loc_range.start),
end: u64::from(val_loc_range.end),
.map(|value_loc_range| Range::OffsetPair {
begin: u64::from(value_loc_range.start),
end: u64::from(value_loc_range.end),
}),
)
.collect(),
@ -415,6 +419,34 @@ impl<'a, 'tcx> FunctionDebugContext<'a, 'tcx> {
gimli::DW_AT_type,
AttributeValue::ThisUnitEntryRef(local_type),
);
let loc_list = LocationList(
Some(Location::BaseAddress {
address: Address::Symbol {
symbol: self.symbol,
addend: 0,
},
})
.into_iter()
.chain(
value_loc_ranges
.iter()
.map(|value_loc_range| Location::OffsetPair {
begin: u64::from(value_loc_range.start),
end: u64::from(value_loc_range.end),
data: Expression(translate_loc(value_loc_range.loc, &context.func.stack_slots).unwrap()),
}),
)
.collect(),
);
let loc_list_id = self.debug_context.dwarf.unit.locations.add(loc_list);
let var_entry = self.debug_context.dwarf.unit.get_mut(var_id);
var_entry.set(
gimli::DW_AT_location,
AttributeValue::LocationListRef(loc_list_id),
);
}
}
@ -510,3 +542,87 @@ impl Writer for WriterRelocate {
self.write_udata_at(offset, 0, size)
}
}
// Adapted from https://github.com/CraneStation/wasmtime/blob/5a1845b4caf7a5dba8eda1fef05213a532ed4259/crates/debug/src/transform/expression.rs#L59-L137
fn map_reg(reg: RegUnit) -> Register {
static mut REG_X86_MAP: Option<HashMap<RegUnit, Register>> = None;
// FIXME lazy initialization?
unsafe {
if REG_X86_MAP.is_none() {
REG_X86_MAP = Some(HashMap::new());
}
if let Some(val) = REG_X86_MAP.as_mut().unwrap().get(&reg) {
return *val;
}
let result = match reg {
0 => X86_64::RAX,
1 => X86_64::RCX,
2 => X86_64::RDX,
3 => X86_64::RBX,
4 => X86_64::RSP,
5 => X86_64::RBP,
6 => X86_64::RSI,
7 => X86_64::RDI,
8 => X86_64::R8,
9 => X86_64::R9,
10 => X86_64::R10,
11 => X86_64::R11,
12 => X86_64::R12,
13 => X86_64::R13,
14 => X86_64::R14,
15 => X86_64::R15,
16 => X86_64::XMM0,
17 => X86_64::XMM1,
18 => X86_64::XMM2,
19 => X86_64::XMM3,
20 => X86_64::XMM4,
21 => X86_64::XMM5,
22 => X86_64::XMM6,
23 => X86_64::XMM7,
24 => X86_64::XMM8,
25 => X86_64::XMM9,
26 => X86_64::XMM10,
27 => X86_64::XMM11,
28 => X86_64::XMM12,
29 => X86_64::XMM13,
30 => X86_64::XMM14,
31 => X86_64::XMM15,
_ => panic!("unknown x86_64 register {}", reg),
};
REG_X86_MAP.as_mut().unwrap().insert(reg, result);
result
}
}
fn translate_loc(loc: ValueLoc, stack_slots: &StackSlots) -> Option<Vec<u8>> {
match loc {
ValueLoc::Reg(reg) => {
let machine_reg = map_reg(reg).0 as u8;
assert!(machine_reg <= 32); // FIXME
Some(vec![gimli::constants::DW_OP_reg0.0 + machine_reg])
}
ValueLoc::Stack(ss) => {
if let Some(ss_offset) = stack_slots[ss].offset {
let endian = gimli::RunTimeEndian::Little;
let mut writer = write::EndianVec::new(endian);
writer
.write_u8(gimli::constants::DW_OP_breg0.0 + X86_64::RBP.0 as u8)
.expect("bp wr");
writer.write_sleb128(ss_offset as i64 + 16).expect("ss wr");
writer
.write_u8(gimli::constants::DW_OP_deref.0 as u8)
.expect("bp wr");
let buf = writer.into_vec();
return Some(buf);
}
None
}
_ => None,
}
}