wasmtime_cranelift/debug/transform/
mod.rs

1use self::debug_transform_logging::dbi_log;
2use self::refs::DebugInfoRefsMap;
3use self::simulate::generate_simulated_dwarf;
4use self::unit::clone_unit;
5use crate::debug::gc::build_dependencies;
6use crate::debug::Compilation;
7use anyhow::Error;
8use cranelift_codegen::isa::TargetIsa;
9use gimli::{write, Dwarf, DwarfPackage, LittleEndian, Section, Unit, UnitSectionOffset};
10use std::{collections::HashSet, fmt::Debug};
11use synthetic::ModuleSyntheticUnit;
12use thiserror::Error;
13use wasmtime_environ::{
14    DefinedFuncIndex, ModuleTranslation, PrimaryMap, StaticModuleIndex, Tunables,
15};
16
17pub use address_transform::AddressTransform;
18
19mod address_transform;
20mod attr;
21mod debug_transform_logging;
22mod expression;
23mod line_program;
24mod range_info_builder;
25mod refs;
26mod simulate;
27mod synthetic;
28mod unit;
29mod utils;
30
31impl<'a> Compilation<'a> {
32    fn function_frame_info(
33        &mut self,
34        module: StaticModuleIndex,
35        func: DefinedFuncIndex,
36    ) -> expression::FunctionFrameInfo<'a> {
37        let (_, func) = self.function(module, func);
38
39        expression::FunctionFrameInfo {
40            value_ranges: &func.value_labels_ranges,
41            memory_offset: self.module_memory_offsets[module].clone(),
42        }
43    }
44}
45
46pub(crate) trait Reader: gimli::Reader<Offset = usize> + Send + Sync {}
47
48impl<'input, Endian> Reader for gimli::EndianSlice<'input, Endian> where
49    Endian: gimli::Endianity + Send + Sync
50{
51}
52
53#[derive(Error, Debug)]
54#[error("Debug info transform error: {0}")]
55pub struct TransformError(&'static str);
56
57pub(crate) struct DebugInputContext<'a> {
58    reachable: &'a HashSet<UnitSectionOffset>,
59}
60
61fn load_dwp<'data>(
62    translation: ModuleTranslation<'data>,
63    buffer: &'data [u8],
64) -> anyhow::Result<DwarfPackage<gimli::EndianSlice<'data, gimli::LittleEndian>>> {
65    let endian_slice = gimli::EndianSlice::new(buffer, LittleEndian);
66
67    let dwarf_package = DwarfPackage::load(
68        |id| -> anyhow::Result<_> {
69            let slice = match id {
70                gimli::SectionId::DebugAbbrev => {
71                    translation.debuginfo.dwarf.debug_abbrev.reader().slice()
72                }
73                gimli::SectionId::DebugInfo => {
74                    translation.debuginfo.dwarf.debug_info.reader().slice()
75                }
76                gimli::SectionId::DebugLine => {
77                    translation.debuginfo.dwarf.debug_line.reader().slice()
78                }
79                gimli::SectionId::DebugStr => {
80                    translation.debuginfo.dwarf.debug_str.reader().slice()
81                }
82                gimli::SectionId::DebugStrOffsets => translation
83                    .debuginfo
84                    .dwarf
85                    .debug_str_offsets
86                    .reader()
87                    .slice(),
88                gimli::SectionId::DebugLoc => translation.debuginfo.debug_loc.reader().slice(),
89                gimli::SectionId::DebugLocLists => {
90                    translation.debuginfo.debug_loclists.reader().slice()
91                }
92                gimli::SectionId::DebugRngLists => {
93                    translation.debuginfo.debug_rnglists.reader().slice()
94                }
95                gimli::SectionId::DebugTypes => {
96                    translation.debuginfo.dwarf.debug_types.reader().slice()
97                }
98                gimli::SectionId::DebugCuIndex => {
99                    translation.debuginfo.debug_cu_index.reader().slice()
100                }
101                gimli::SectionId::DebugTuIndex => {
102                    translation.debuginfo.debug_tu_index.reader().slice()
103                }
104                _ => &buffer,
105            };
106
107            Ok(gimli::EndianSlice::new(slice, gimli::LittleEndian))
108        },
109        endian_slice,
110    )?;
111
112    Ok(dwarf_package)
113}
114
115/// Attempts to load a DWARF package using the passed bytes.
116fn read_dwarf_package_from_bytes<'data>(
117    dwp_bytes: &'data [u8],
118    buffer: &'data [u8],
119    tunables: &Tunables,
120) -> Option<DwarfPackage<gimli::EndianSlice<'data, gimli::LittleEndian>>> {
121    let mut validator = wasmparser::Validator::new();
122    let parser = wasmparser::Parser::new(0);
123    let mut types = wasmtime_environ::ModuleTypesBuilder::new(&validator);
124    let translation =
125        match wasmtime_environ::ModuleEnvironment::new(tunables, &mut validator, &mut types)
126            .translate(parser, dwp_bytes)
127        {
128            Ok(translation) => translation,
129            Err(e) => {
130                log::warn!("failed to parse wasm dwarf package: {e:?}");
131                return None;
132            }
133        };
134
135    match load_dwp(translation, buffer) {
136        Ok(package) => Some(package),
137        Err(err) => {
138            log::warn!("Failed to load Dwarf package {}", err);
139            None
140        }
141    }
142}
143
144pub fn transform_dwarf(
145    isa: &dyn TargetIsa,
146    compilation: &mut Compilation<'_>,
147) -> Result<write::Dwarf, Error> {
148    dbi_log!("Commencing DWARF transform for {:?}", compilation);
149
150    let mut transforms = PrimaryMap::new();
151    for (i, _) in compilation.translations.iter() {
152        transforms.push(AddressTransform::new(compilation, i));
153    }
154
155    let buffer = Vec::new();
156
157    let dwarf_package = compilation
158        .dwarf_package_bytes
159        .map(
160            |bytes| -> Option<DwarfPackage<gimli::EndianSlice<'_, gimli::LittleEndian>>> {
161                read_dwarf_package_from_bytes(bytes, &buffer, compilation.tunables)
162            },
163        )
164        .flatten();
165
166    let reachable = build_dependencies(compilation, &dwarf_package, &transforms)?.get_reachable();
167
168    let out_encoding = gimli::Encoding {
169        format: gimli::Format::Dwarf32,
170        version: 4, // TODO: this should be configurable
171        address_size: isa.pointer_bytes(),
172    };
173    let mut out_strings = write::StringTable::default();
174    let mut out_units = write::UnitTable::default();
175
176    let out_line_strings = write::LineStringTable::default();
177    let mut pending_di_refs = Vec::new();
178    let mut di_ref_map = DebugInfoRefsMap::new();
179    let mut vmctx_ptr_die_refs = PrimaryMap::new();
180
181    let mut translated = HashSet::new();
182
183    for (module, translation) in compilation.translations.iter() {
184        dbi_log!("[== Transforming CUs for module #{} ==]", module.as_u32());
185
186        let addr_tr = &transforms[module];
187        let di = &translation.debuginfo;
188        let context = DebugInputContext {
189            reachable: &reachable,
190        };
191        let out_module_synthetic_unit = ModuleSyntheticUnit::new(
192            module,
193            compilation,
194            out_encoding,
195            &mut out_units,
196            &mut out_strings,
197        );
198        // TODO-DebugInfo-Cleanup: move the simulation code to be per-module and delete this map.
199        vmctx_ptr_die_refs.push(out_module_synthetic_unit.vmctx_ptr_die_ref());
200
201        let mut iter = di.dwarf.debug_info.units();
202        while let Some(header) = iter.next().unwrap_or(None) {
203            let unit = di.dwarf.unit(header)?;
204
205            let mut resolved_unit = None;
206            let mut split_dwarf = None;
207
208            if unit.dwo_id.is_some() {
209                if let Some(dwarf_package) = &dwarf_package {
210                    if let Some((fused, fused_dwarf)) =
211                        replace_unit_from_split_dwarf(&unit, dwarf_package, &di.dwarf)
212                    {
213                        resolved_unit = Some(fused);
214                        split_dwarf = Some(fused_dwarf);
215                    }
216                }
217            }
218
219            if let Some((id, ref_map, pending_refs)) = clone_unit(
220                compilation,
221                module,
222                &unit,
223                resolved_unit.as_ref(),
224                split_dwarf.as_ref(),
225                &context,
226                &addr_tr,
227                out_encoding,
228                &out_module_synthetic_unit,
229                &mut out_units,
230                &mut out_strings,
231                &mut translated,
232                isa,
233            )? {
234                di_ref_map.insert(&header, id, ref_map);
235                pending_di_refs.push((id, pending_refs));
236            }
237        }
238    }
239    di_ref_map.patch(pending_di_refs.into_iter(), &mut out_units);
240
241    generate_simulated_dwarf(
242        compilation,
243        &transforms,
244        &translated,
245        out_encoding,
246        &vmctx_ptr_die_refs,
247        &mut out_units,
248        &mut out_strings,
249        isa,
250    )?;
251
252    Ok(write::Dwarf {
253        units: out_units,
254        line_programs: vec![],
255        line_strings: out_line_strings,
256        strings: out_strings,
257    })
258}
259
260fn replace_unit_from_split_dwarf<'a>(
261    unit: &'a Unit<gimli::EndianSlice<'a, gimli::LittleEndian>, usize>,
262    dwp: &DwarfPackage<gimli::EndianSlice<'a, gimli::LittleEndian>>,
263    parent: &Dwarf<gimli::EndianSlice<'a, gimli::LittleEndian>>,
264) -> Option<(
265    Unit<gimli::EndianSlice<'a, gimli::LittleEndian>, usize>,
266    Dwarf<gimli::EndianSlice<'a, gimli::LittleEndian>>,
267)> {
268    let dwo_id = unit.dwo_id?;
269    let split_unit_dwarf = dwp.find_cu(dwo_id, parent).ok()??;
270    let unit_header = split_unit_dwarf.debug_info.units().next().ok()??;
271    let mut split_unit = split_unit_dwarf.unit(unit_header).ok()?;
272    split_unit.copy_relocated_attributes(unit);
273    Some((split_unit, split_unit_dwarf))
274}
wasmtime_cranelift/debug/transform/mod.rs

wasmtime_cranelift/debug/transform/
mod.rs
