wasmtime_environ/
module_artifacts.rs

1//! Definitions of runtime structures and metadata which are serialized into ELF
2//! with `bincode` as part of a module's compilation process.
3
4use crate::prelude::*;
5use crate::{
6    EntityRef, FilePos, FuncIndex, FuncKey, FuncKeyIndex, FuncKeyKind, FuncKeyNamespace, Module,
7    PanicOnOom as _,
8};
9use core::ops::Range;
10use core::{fmt, u32};
11use core::{iter, str};
12use serde_derive::{Deserialize, Serialize};
13#[cfg(feature = "rr")]
14use sha2::{Digest, Sha256};
15
16/// Description of where a function is located in the text section of a
17/// compiled image.
18#[derive(Copy, Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
19pub struct FunctionLoc {
20    /// The byte offset from the start of the text section where this
21    /// function starts.
22    pub start: u32,
23    /// The byte length of this function's function body.
24    pub length: u32,
25}
26
27impl FunctionLoc {
28    /// Is this an empty function location?
29    #[inline]
30    pub fn is_empty(&self) -> bool {
31        self.length == 0
32    }
33}
34
35/// The checksum of a Wasm binary.
36///
37/// Allows for features requiring the exact same Wasm Module (e.g. deterministic replay)
38/// to verify that the binary used matches the one originally compiled.
39#[derive(Copy, Clone, Default, PartialEq, Eq, Ord, PartialOrd, Debug, Serialize, Deserialize)]
40pub struct WasmChecksum([u8; 32]);
41
42impl WasmChecksum {
43    /// Construct a [`WasmChecksum`] from the given wasm binary, used primarily for integrity
44    /// checks on compiled modules when recording configs are enabled. The checksum is not
45    /// computed when recording is disabled to prevent pessimization of non-recorded compilations.
46    #[cfg(feature = "rr")]
47    pub fn from_binary(bin: &[u8], recording: bool) -> WasmChecksum {
48        if recording {
49            WasmChecksum(Sha256::digest(bin).into())
50        } else {
51            WasmChecksum::default()
52        }
53    }
54
55    /// This method requires the `rr` feature to actual compute a checksum. Since the `rr`
56    /// feature is disabled, this only returns a default checksum value of all zeros.
57    #[cfg(not(feature = "rr"))]
58    pub fn from_binary(_: &[u8], _: bool) -> WasmChecksum {
59        WasmChecksum::default()
60    }
61}
62
63impl core::ops::Deref for WasmChecksum {
64    type Target = [u8; 32];
65
66    fn deref(&self) -> &Self::Target {
67        &self.0
68    }
69}
70
71/// A builder for a `CompiledFunctionsTable`.
72pub struct CompiledFunctionsTableBuilder {
73    inner: CompiledFunctionsTable,
74}
75
76impl CompiledFunctionsTableBuilder {
77    /// Create a new builder.
78    pub fn new() -> Self {
79        Self {
80            inner: CompiledFunctionsTable {
81                namespaces: TryPrimaryMap::new(),
82                func_loc_starts: TryPrimaryMap::new(),
83                sparse_starts: TryPrimaryMap::new(),
84                src_loc_starts: TryPrimaryMap::new(),
85                sparse_indices: TryPrimaryMap::new(),
86                func_locs: TryPrimaryMap::new(),
87                src_locs: TryPrimaryMap::new(),
88            },
89        }
90    }
91
92    fn last_namespace(&self) -> Option<FuncKeyNamespace> {
93        let (_, &ns) = self.inner.namespaces.last()?;
94        Some(ns)
95    }
96
97    fn last_key_index(&self) -> Option<FuncKeyIndex> {
98        let (ns_idx, ns) = self.inner.namespaces.last()?;
99        let start = self.inner.func_loc_starts[ns_idx];
100        if CompiledFunctionsTable::is_dense(ns.kind()) {
101            let len = self.inner.func_locs.len();
102            let len = u32::try_from(len).unwrap();
103            let key_index = len - start.as_u32();
104            let key_index = FuncKeyIndex::from_raw(key_index);
105            Some(key_index)
106        } else {
107            let sparse_start = self.inner.sparse_starts[ns_idx];
108            if self.inner.sparse_indices.len() > sparse_start.index() {
109                let (_, &key_index) = self.inner.sparse_indices.last().unwrap();
110                Some(key_index)
111            } else {
112                None
113            }
114        }
115    }
116
117    fn last_func_loc(&self) -> Option<FunctionLoc> {
118        let (_, &loc) = self.inner.func_locs.last()?;
119        Some(loc)
120    }
121
122    /// Push a new entry into this builder.
123    ///
124    /// Panics if the key or function location is out of order.
125    pub fn push_func(
126        &mut self,
127        key: FuncKey,
128        func_loc: FunctionLoc,
129        src_loc: FilePos,
130    ) -> &mut Self {
131        let (key_ns, key_index) = key.into_parts();
132
133        assert!(
134            self.last_namespace().is_none_or(|ns| ns <= key_ns),
135            "`FuncKey`s pushed out of order"
136        );
137        assert!(
138            self.last_key_index().is_none_or(
139                |i| i <= key_index || self.last_namespace().is_some_and(|ns| ns != key_ns)
140            ),
141            "`FuncKey`s pushed out of order"
142        );
143        assert!(
144            self.last_func_loc()
145                .is_none_or(|l| l.start + l.length <= func_loc.start),
146            "`FunctionLoc`s pushed out of order"
147        );
148
149        // Make sure that there is a `kind` entry for this key's kind.
150        let kind_start_index = self
151            .inner
152            .namespaces
153            .last()
154            .and_then(|(ns_idx, ns)| {
155                if *ns == key_ns {
156                    Some(self.inner.func_loc_starts[ns_idx])
157                } else {
158                    None
159                }
160            })
161            .unwrap_or_else(|| {
162                let start = self.inner.func_locs.next_key();
163                let ns_idx = self.inner.namespaces.push(key_ns).panic_on_oom();
164                let ns_idx2 = self.inner.func_loc_starts.push(start).panic_on_oom();
165                let ns_idx3 = self
166                    .inner
167                    .sparse_starts
168                    .push(self.inner.sparse_indices.next_key())
169                    .panic_on_oom();
170                let ns_idx4 = self
171                    .inner
172                    .src_loc_starts
173                    .push(self.inner.src_locs.next_key())
174                    .panic_on_oom();
175                debug_assert_eq!(ns_idx, ns_idx2);
176                debug_assert_eq!(ns_idx, ns_idx3);
177                debug_assert_eq!(ns_idx, ns_idx4);
178                start
179            });
180
181        if CompiledFunctionsTable::is_dense(key.kind()) {
182            // Figure out the index within `func_locs` for this key's entry.
183            let index = kind_start_index.as_u32() + key_index.into_raw();
184            let index = FuncLocIndex::from_u32(index);
185            debug_assert!(self.inner.func_locs.get(index).is_none());
186
187            // Fill in null entries for any key indices that have been omitted.
188            //
189            // Note that we need a null `FunctionLoc`, but we also need
190            // `func_locs` to be sorted so that we support reverse
191            // lookups. Therefore, we take care to create an empty function
192            // location that starts at the text offset that the previous one (if
193            // any) ends at, and use that as our null entry.
194            let null_func_loc = FunctionLoc {
195                start: self
196                    .last_func_loc()
197                    .map(|l| l.start + l.length)
198                    .unwrap_or_default(),
199                length: 0,
200            };
201            let gap = index.index() - self.inner.func_locs.len();
202            self.inner
203                .func_locs
204                .try_extend(iter::repeat(null_func_loc).take(gap))
205                .panic_on_oom();
206            debug_assert_eq!(index, self.inner.func_locs.next_key());
207
208            if CompiledFunctionsTable::has_src_locs(key_ns.kind()) {
209                self.inner
210                    .src_locs
211                    .try_extend(iter::repeat(FilePos::none()).take(gap))
212                    .panic_on_oom();
213            }
214        } else {
215            debug_assert!(
216                src_loc.is_none(),
217                "sparse keys do not have source locations"
218            );
219            self.inner.sparse_indices.push(key_index).panic_on_oom();
220        }
221
222        // And finally, we push this entry.
223        self.inner.func_locs.push(func_loc).panic_on_oom();
224        if CompiledFunctionsTable::has_src_locs(key_ns.kind()) {
225            self.inner.src_locs.push(src_loc).panic_on_oom();
226        } else {
227            debug_assert!(src_loc.is_none());
228        }
229
230        self
231    }
232
233    /// Finish construction of the `CompiledFunctionsTable`.
234    pub fn finish(self) -> CompiledFunctionsTable {
235        self.inner
236    }
237}
238
239#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord, Serialize, Deserialize)]
240struct NamespaceIndex(u32);
241cranelift_entity::entity_impl!(NamespaceIndex);
242
243#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord, Serialize, Deserialize)]
244struct FuncLocIndex(u32);
245cranelift_entity::entity_impl!(FuncLocIndex);
246
247#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord, Serialize, Deserialize)]
248struct SparseIndex(u32);
249cranelift_entity::entity_impl!(SparseIndex);
250
251#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord, Serialize, Deserialize)]
252struct SrcLocIndex(u32);
253cranelift_entity::entity_impl!(SrcLocIndex);
254
255/// A table describing the set of functions compiled into an artifact, their
256/// locations within the text section, and etc...
257///
258/// Logically, this type is a map from a `FuncKey` to the associated function's
259///
260/// * location within the associated text section, and
261/// * optional source location.
262///
263/// How this map is *actually* implemented is with a series of lookup and binary
264/// search tables, split out in a data-oriented, struct-of-arrays style. We
265/// organize the data in this way is service of three goals:
266///
267/// 1. Provide fast look ups: We need to look up the metadata for a function by
268///    its key at runtime. During instantiation, for example, we need to create
269///    `VMFuncRef`s for escaping functions and this requires looking up the
270///    locations of those Wasm functions and their associated array-to-Wasm
271///    trampolines.
272///
273/// 2. Keep memory overheads low and code size small: This type is serialized
274///    into all of our ELF artifacts and deserialized into all `Module`s and
275///    `Component`s at runtime.
276///
277/// 3. Be generic over any kind of function (whether defined Wasm function,
278///    trampoline, or etc...) that we compile: Adding a new kind of trampoline,
279///    for example, should not require updating this structure to add a new
280///    table of the function locations for just trampolines of that new kind. We
281///    should be able to store and query all kinds of functions uniformly.
282//
283// TODO: This structure could be directly encoded as raw ELF sections, instead
284// of a `struct` containing a bunch of `PrimaryMap`s, which would allow us to
285// avoid the serialize/deserialize runtime costs.
286#[derive(Debug, Serialize, Deserialize)]
287pub struct CompiledFunctionsTable {
288    /// A binary-search index for this table, mapping raw `FuncKeyNamespace`s to
289    /// their associated `NamespaceIndex`. That `NamespaceIndex` can then be
290    /// used to find the range of other entity indices that are specific to that
291    /// namespace.
292    namespaces: TryPrimaryMap<NamespaceIndex, FuncKeyNamespace>,
293
294    /// `self.func_loc_starts[i]..self.func_loc_starts[i+1]` describes the range
295    /// within `self.func_locs` whose entries are associated with the namespace
296    /// `self.index[i]`.
297    ///
298    /// When `self.func_loc_starts[i+1]` is out of bounds, then the range is to
299    /// the end of `self.func_locs`.
300    func_loc_starts: TryPrimaryMap<NamespaceIndex, FuncLocIndex>,
301
302    /// `self.sparse_starts[i]..self.sparse_starts[i+1]` describes the range
303    /// within `self.sparse_indices` whose entries are associated with the
304    /// namespace `self.index[i]`.
305    ///
306    /// When `self.sparse_starts[i+1]` is out of bounds, then the range is to
307    /// the end of `self.sparse_indices`.
308    ///
309    /// Entries are only valid for sparse, non-dense namespaces.
310    sparse_starts: TryPrimaryMap<NamespaceIndex, SparseIndex>,
311
312    /// `self.src_loc_starts[i]..self.src_loc_starts[i+1]` describes the range
313    /// within `self.src_loc_indices` whose entries are associated with the
314    /// namespace `self.index[i]`.
315    ///
316    /// When `self.src_loc_starts[i+1]` is out of bounds, then the range is to
317    /// the end of `self.src_locs`.
318    ///
319    /// Entries are only valid for namespaces whose functions have source
320    /// locations.
321    src_loc_starts: TryPrimaryMap<NamespaceIndex, SrcLocIndex>,
322
323    /// `self.sparse_indices[i]` contains the index part of
324    /// `FuncKey::from_parts(ns, index)` where `ns` is determined by
325    /// `self.sparse_starts` and is a sparse, non-dense key kind. (Note that for
326    /// dense keys, this information is implicitly encoded in their offset from
327    /// the namespace's start index.)
328    ///
329    /// This is sorted to allow for binary searches.
330    sparse_indices: TryPrimaryMap<SparseIndex, FuncKeyIndex>,
331
332    /// `self.func_locs[i]` contains the location within the text section of
333    /// `FuncKey::from_parts(self.namespaces[ns], i - start)`'s function, where
334    /// `ns` and `start` are determined by `self.func_loc_starts`.
335    ///
336    /// Values are sorted by function location to support reverse queries from
337    /// function location back to `FuncKey`.
338    ///
339    /// The absence of a function location (for gaps in dense namespaces) is
340    /// represented with `FunctionLoc::none()`.
341    func_locs: TryPrimaryMap<FuncLocIndex, FunctionLoc>,
342
343    /// `self.src_locs[i]` contains the initial source location of
344    /// `FuncKey::from_parts(self.namespaces[ns], i - start)`'s function, where
345    /// `ns` and `start` are determined by `self.src_loc_starts`.
346    ///
347    /// The absence of a source location is represented by `FilePos::none()`.
348    src_locs: TryPrimaryMap<SrcLocIndex, FilePos>,
349}
350
351impl CompiledFunctionsTable {
352    #[inline]
353    fn namespace_index(&self, namespace: FuncKeyNamespace) -> Option<NamespaceIndex> {
354        const LINEAR_SEARCH_LIMIT: usize = 32;
355        if self.namespaces.len() <= LINEAR_SEARCH_LIMIT {
356            self.namespaces
357                .iter()
358                .find_map(|(idx, ns)| if *ns == namespace { Some(idx) } else { None })
359        } else {
360            self.namespaces
361                .binary_search_values_by_key(&namespace, |ns| *ns)
362                .ok()
363        }
364    }
365
366    #[inline]
367    fn func_loc_range(&self, ns_idx: NamespaceIndex) -> Range<FuncLocIndex> {
368        let start = self.func_loc_starts[ns_idx];
369        let next_ns_idx = NamespaceIndex::from_u32(ns_idx.as_u32() + 1);
370        let end = self
371            .func_loc_starts
372            .get(next_ns_idx)
373            .copied()
374            .unwrap_or_else(|| self.func_locs.next_key());
375        start..end
376    }
377
378    fn sparse_range(&self, ns_idx: NamespaceIndex) -> Range<SparseIndex> {
379        debug_assert!(!Self::is_dense(self.namespaces[ns_idx].kind()));
380        let start = self.sparse_starts[ns_idx];
381        let next_ns_idx = NamespaceIndex::from_u32(ns_idx.as_u32() + 1);
382        let end = self
383            .sparse_starts
384            .get(next_ns_idx)
385            .copied()
386            .unwrap_or_else(|| self.sparse_indices.next_key());
387        start..end
388    }
389
390    fn src_loc_range(&self, ns_idx: NamespaceIndex) -> Range<SrcLocIndex> {
391        debug_assert!(Self::has_src_locs(self.namespaces[ns_idx].kind()));
392        let start = self.src_loc_starts[ns_idx];
393        let next_ns_idx = NamespaceIndex::from_u32(ns_idx.as_u32() + 1);
394        let end = self
395            .src_loc_starts
396            .get(next_ns_idx)
397            .copied()
398            .unwrap_or_else(|| self.src_locs.next_key());
399        start..end
400    }
401
402    /// Get the index within `self.{func_locs,src_locs}` that is associated with
403    /// the given `key`, if any.
404    #[inline]
405    fn func_loc_index(&self, key: FuncKey) -> Option<FuncLocIndex> {
406        let (key_ns, key_index) = key.into_parts();
407        let ns_idx = self.namespace_index(key_ns)?;
408        let Range { start, end } = self.func_loc_range(ns_idx);
409
410        let index = if Self::is_dense(key.kind()) {
411            let index = start.as_u32().checked_add(key_index.into_raw())?;
412            FuncLocIndex::from_u32(index)
413        } else {
414            let sparse_range = self.sparse_range(ns_idx);
415            let sparse_subslice = self.sparse_indices.get_range(sparse_range).unwrap();
416            match sparse_subslice.binary_search(&key_index) {
417                Ok(i) => FuncLocIndex::new(start.index() + i),
418                Err(_) => return None,
419            }
420        };
421
422        if index < end { Some(index) } else { None }
423    }
424
425    /// Get the location of the function associated with the given `key` inside
426    /// the text section, if any.
427    #[inline]
428    pub fn func_loc(&self, key: FuncKey) -> Option<&FunctionLoc> {
429        let index = self.func_loc_index(key)?;
430        let loc = &self.func_locs[index];
431        if loc.is_empty() { None } else { Some(loc) }
432    }
433
434    fn src_loc_index(&self, key: FuncKey) -> Option<SrcLocIndex> {
435        let (key_ns, key_index) = key.into_parts();
436        if !Self::has_src_locs(key_ns.kind()) {
437            return None;
438        }
439
440        let ns_idx = self.namespace_index(key_ns)?;
441        let Range { start, end } = self.src_loc_range(ns_idx);
442
443        debug_assert!(Self::is_dense(key_ns.kind()));
444        let index = start.as_u32().checked_add(key_index.into_raw())?;
445        let index = SrcLocIndex::from_u32(index);
446        if index >= end {
447            return None;
448        }
449
450        Some(index)
451    }
452
453    /// Get the initial source location of the function associated with the
454    /// given `key`, if any.
455    pub fn src_loc(&self, key: FuncKey) -> Option<FilePos> {
456        let index = self.src_loc_index(key)?;
457        let loc = self.src_locs[index];
458        if loc.is_none() { None } else { Some(loc) }
459    }
460
461    /// Given an offset into the text section, get the key for its associated
462    /// function and its offset within that function.
463    pub fn func_by_text_offset(&self, text_offset: u32) -> Option<FuncKey> {
464        let index = match self.func_locs.as_values_slice().binary_search_by(|loc| {
465            if loc.is_empty() {
466                loc.start
467                    .cmp(&text_offset)
468                    .then_with(|| core::cmp::Ordering::Less)
469            } else {
470                if loc.start > text_offset {
471                    core::cmp::Ordering::Greater
472                } else if loc.start + loc.length <= text_offset {
473                    core::cmp::Ordering::Less
474                } else {
475                    debug_assert!(loc.start <= text_offset);
476                    debug_assert!(text_offset < loc.start + loc.length);
477                    core::cmp::Ordering::Equal
478                }
479            }
480        }) {
481            // Exact match, the offset is at the end of this function.
482            Ok(k) => k,
483            // Not an exact match: `k` is where the offset would be
484            // "inserted". Since we key based on the end, function `k` might
485            // contain the offset, so we'll validate on the range check
486            // below.
487            Err(k) => k,
488        };
489        let index = FuncLocIndex::new(index);
490
491        // Make sure that the text offset is actually within this function.
492        // Non-exact binary search results can either be because we have a text
493        // offset within a function but not exactly at its inclusive end, or
494        // because the text offset is not within any of our functions. We filter
495        // that latter case out with this check.
496        let loc = self.func_locs.get(index)?;
497        let start = loc.start;
498        let end = start + loc.length;
499        if text_offset < start || end < text_offset {
500            return None;
501        }
502
503        let ns_idx = match self
504            .func_loc_starts
505            .binary_search_values_by_key(&index, |s| *s)
506        {
507            // Exact match: `i` is the entry's index.
508            Ok(i) => i,
509            // Not an exact match: the index, if it were the start of a
510            // namespace's range, would be at `i`. Therefore, our namespace
511            // entry is actually at index `i - 1`.
512            Err(i) => {
513                let i = i.as_u32();
514                assert_ne!(i, 0);
515                NamespaceIndex::from_u32(i - 1)
516            }
517        };
518        let key_ns = self.namespaces[ns_idx];
519        let start = self.func_loc_starts[ns_idx];
520
521        let key_index = if Self::is_dense(key_ns.kind()) {
522            let key_index = index.as_u32() - start.as_u32();
523            FuncKeyIndex::from_raw(key_index)
524        } else {
525            let sparse_offset = index.as_u32() - start.as_u32();
526            let sparse_start = self.sparse_starts[ns_idx];
527            let sparse_index = SparseIndex::from_u32(sparse_start.as_u32() + sparse_offset);
528            debug_assert!(
529                {
530                    let range = self.sparse_range(ns_idx);
531                    range.start <= sparse_index && sparse_index < range.end
532                },
533                "{sparse_index:?} is not within {:?}",
534                self.sparse_range(ns_idx)
535            );
536            self.sparse_indices[sparse_index]
537        };
538        let key = FuncKey::from_parts(key_ns, key_index);
539
540        Some(key)
541    }
542
543    /// Whether the given kind's index space is (generally) densely populated
544    /// and therefore we should densely pack them in the table for `O(1)`
545    /// lookups; otherwise, we should avoid code size bloat by using the sparse
546    /// table indirection and `O(log n)` binary search lookups.
547    fn is_dense(kind: FuncKeyKind) -> bool {
548        match kind {
549            FuncKeyKind::DefinedWasmFunction
550            | FuncKeyKind::WasmToArrayTrampoline
551            | FuncKeyKind::PulleyHostCall => true,
552
553            FuncKeyKind::ArrayToWasmTrampoline
554            | FuncKeyKind::WasmToBuiltinTrampoline
555            | FuncKeyKind::PatchableToBuiltinTrampoline
556            | FuncKeyKind::ModuleStartup => false,
557
558            #[cfg(feature = "component-model")]
559            FuncKeyKind::ComponentTrampoline
560            | FuncKeyKind::ResourceDropTrampoline
561            | FuncKeyKind::UnsafeIntrinsic => true,
562        }
563    }
564
565    /// Whether the given function kind has source locations or not.
566    fn has_src_locs(kind: FuncKeyKind) -> bool {
567        match kind {
568            FuncKeyKind::DefinedWasmFunction => true,
569            FuncKeyKind::ArrayToWasmTrampoline
570            | FuncKeyKind::WasmToArrayTrampoline
571            | FuncKeyKind::WasmToBuiltinTrampoline
572            | FuncKeyKind::PatchableToBuiltinTrampoline
573            | FuncKeyKind::PulleyHostCall
574            | FuncKeyKind::ModuleStartup => false,
575            #[cfg(feature = "component-model")]
576            FuncKeyKind::ComponentTrampoline
577            | FuncKeyKind::ResourceDropTrampoline
578            | FuncKeyKind::UnsafeIntrinsic => false,
579        }
580    }
581}
582
583/// Secondary in-memory results of module compilation.
584///
585/// This opaque structure can be optionally passed back to
586/// `CompiledModule::from_artifacts` to avoid decoding extra information there.
587#[derive(Serialize, Deserialize)]
588pub struct CompiledModuleInfo {
589    /// Type information about the compiled WebAssembly module.
590    pub module: Module,
591
592    /// General compilation metadata.
593    pub meta: Metadata,
594
595    /// Sorted list, by function index, of names we have for this module.
596    pub func_names: Vec<FunctionName>,
597
598    /// Checksum of the source Wasm binary from which this module was compiled.
599    pub checksum: WasmChecksum,
600}
601
602/// The name of a function stored in the
603/// [`ELF_NAME_DATA`](crate::obj::ELF_NAME_DATA) section.
604#[derive(Serialize, Deserialize)]
605pub struct FunctionName {
606    /// The Wasm function index of this function.
607    pub idx: FuncIndex,
608    /// The offset of the name in the
609    /// [`ELF_NAME_DATA`](crate::obj::ELF_NAME_DATA) section.
610    pub offset: u32,
611    /// The length of the name in bytes.
612    pub len: u32,
613}
614
615/// Metadata associated with a compiled ELF artifact.
616#[derive(Serialize, Deserialize)]
617pub struct Metadata {
618    /// Whether or not the original wasm module contained debug information that
619    /// we skipped and did not parse.
620    pub has_unparsed_debuginfo: bool,
621
622    /// Offset in the original wasm file to the code section.
623    pub code_section_offset: u64,
624
625    /// Whether or not custom wasm-specific dwarf sections were inserted into
626    /// the ELF image.
627    ///
628    /// Note that even if this flag is `true` sections may be missing if they
629    /// weren't found in the original wasm module itself.
630    pub has_wasm_debuginfo: bool,
631
632    /// Dwarf sections and the offsets at which they're stored in the
633    /// ELF_WASMTIME_DWARF
634    pub dwarf: Vec<(u8, Range<u64>)>,
635}
636
637/// Value of a configured setting for a [`Compiler`](crate::Compiler)
638#[derive(Serialize, Deserialize, Hash, Eq, PartialEq, Debug)]
639pub enum FlagValue<'a> {
640    /// Name of the value that has been configured for this setting.
641    Enum(&'a str),
642    /// The numerical value of the configured settings.
643    Num(u8),
644    /// Whether the setting is on or off.
645    Bool(bool),
646}
647
648impl fmt::Display for FlagValue<'_> {
649    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
650        match self {
651            Self::Enum(v) => v.fmt(f),
652            Self::Num(v) => v.fmt(f),
653            Self::Bool(v) => v.fmt(f),
654        }
655    }
656}
657
658/// Types of objects that can be created by `Compiler::object`
659pub enum ObjectKind {
660    /// A core wasm compilation artifact
661    Module,
662    /// A component compilation artifact
663    Component,
664}
665
666#[cfg(test)]
667mod tests {
668    use super::*;
669    use crate::{DefinedFuncIndex, StaticModuleIndex};
670
671    fn func_loc(range: Range<u32>) -> FunctionLoc {
672        FunctionLoc {
673            start: range.start,
674            length: range.end - range.start,
675        }
676    }
677
678    fn def_func_key(m: u32, f: u32) -> FuncKey {
679        FuncKey::DefinedWasmFunction(
680            StaticModuleIndex::from_u32(m),
681            DefinedFuncIndex::from_u32(f),
682        )
683    }
684
685    fn array_to_wasm_tramp_key(m: u32, f: u32) -> FuncKey {
686        FuncKey::ArrayToWasmTrampoline(
687            StaticModuleIndex::from_u32(m),
688            DefinedFuncIndex::from_u32(f),
689        )
690    }
691
692    fn make_test_table() -> CompiledFunctionsTable {
693        let mut builder = CompiledFunctionsTableBuilder::new();
694
695        builder
696            // ========= Dense =========
697            .push_func(def_func_key(0, 0), func_loc(0..10), FilePos::new(111))
698            .push_func(def_func_key(0, 1), func_loc(10..20), FilePos::new(222))
699            .push_func(def_func_key(0, 2), func_loc(20..30), FilePos::none())
700            // Gap in dense keys!
701            .push_func(def_func_key(0, 5), func_loc(30..40), FilePos::new(333))
702            // ========= Sparse =========
703            .push_func(
704                array_to_wasm_tramp_key(0, 1),
705                func_loc(100..110),
706                FilePos::none(),
707            )
708            .push_func(
709                array_to_wasm_tramp_key(0, 2),
710                func_loc(110..120),
711                FilePos::none(),
712            )
713            .push_func(
714                array_to_wasm_tramp_key(0, 5),
715                func_loc(120..130),
716                FilePos::none(),
717            );
718
719        builder.finish()
720    }
721
722    #[test]
723    fn src_locs() {
724        let table = make_test_table();
725
726        for (key, expected) in [
727            (def_func_key(0, 0), Some(FilePos::new(111))),
728            (def_func_key(0, 1), Some(FilePos::new(222))),
729            (def_func_key(0, 2), None),
730            (def_func_key(0, 3), None),
731            (def_func_key(0, 4), None),
732            (def_func_key(0, 5), Some(FilePos::new(333))),
733            (array_to_wasm_tramp_key(0, 0), None),
734            (array_to_wasm_tramp_key(0, 1), None),
735            (array_to_wasm_tramp_key(0, 2), None),
736            (array_to_wasm_tramp_key(0, 3), None),
737            (array_to_wasm_tramp_key(0, 4), None),
738            (array_to_wasm_tramp_key(0, 5), None),
739        ] {
740            eprintln!("Checking key {key:?}");
741            let actual = table.src_loc(key);
742            assert_eq!(expected, actual);
743        }
744    }
745
746    #[test]
747    fn func_locs() {
748        let table = make_test_table();
749
750        for (key, expected) in [
751            (def_func_key(0, 0), Some(0)),
752            (def_func_key(0, 1), Some(10)),
753            (def_func_key(0, 2), Some(20)),
754            (def_func_key(0, 3), None),
755            (def_func_key(0, 4), None),
756            (def_func_key(0, 5), Some(30)),
757            (array_to_wasm_tramp_key(0, 0), None),
758            (array_to_wasm_tramp_key(0, 1), Some(100)),
759            (array_to_wasm_tramp_key(0, 2), Some(110)),
760            (array_to_wasm_tramp_key(0, 3), None),
761            (array_to_wasm_tramp_key(0, 4), None),
762            (array_to_wasm_tramp_key(0, 5), Some(120)),
763        ] {
764            let actual = table.func_loc(key);
765            match (expected, actual) {
766                (None, None) => {}
767                (Some(expected), Some(actual)) => assert_eq!(expected, actual.start),
768                (None, Some(actual)) => {
769                    panic!("expected no function location for {key:?}, got {actual:?}")
770                }
771                (Some(_), None) => {
772                    panic!("expected a function location for {key:?}, but got nothing")
773                }
774            }
775        }
776    }
777
778    #[test]
779    fn reverse_func_locs() {
780        let table = make_test_table();
781
782        for (range, expected) in [
783            (0..10, Some(def_func_key(0, 0))),
784            (10..20, Some(def_func_key(0, 1))),
785            (20..30, Some(def_func_key(0, 2))),
786            (30..40, Some(def_func_key(0, 5))),
787            (40..100, None),
788            (100..110, Some(array_to_wasm_tramp_key(0, 1))),
789            (110..120, Some(array_to_wasm_tramp_key(0, 2))),
790            (120..130, Some(array_to_wasm_tramp_key(0, 5))),
791            (140..150, None),
792        ] {
793            for i in range {
794                eprintln!("Checking offset {i}");
795                let actual = table.func_by_text_offset(i);
796                assert_eq!(expected, actual);
797            }
798        }
799    }
800
801    #[test]
802    fn reverse_lookups() {
803        use arbitrary::{Result, Unstructured};
804
805        arbtest::arbtest(|u| run(u)).budget_ms(1_000);
806
807        fn run(u: &mut Unstructured<'_>) -> Result<()> {
808            let mut funcs = Vec::new();
809
810            // Build up a random set of functions with random indices.
811            for _ in 0..u.int_in_range(1..=200)? {
812                #[cfg(feature = "component-model")]
813                let choice = u.int_in_range(0..=6)?;
814                #[cfg(not(feature = "component-model"))]
815                let choice = u.int_in_range(0..=4)?;
816
817                let key = match choice {
818                    0 => FuncKey::DefinedWasmFunction(idx(u, 10)?, idx(u, 200)?),
819                    1 => FuncKey::ArrayToWasmTrampoline(idx(u, 10)?, idx(u, 200)?),
820                    2 => FuncKey::WasmToArrayTrampoline(idx(u, 100)?),
821                    3 => FuncKey::WasmToBuiltinTrampoline(u.arbitrary()?),
822                    4 => FuncKey::PulleyHostCall(u.arbitrary()?),
823                    #[cfg(feature = "component-model")]
824                    5 => FuncKey::ComponentTrampoline(u.arbitrary()?, idx(u, 50)?),
825                    #[cfg(feature = "component-model")]
826                    6 => FuncKey::ResourceDropTrampoline,
827                    _ => unreachable!(),
828                };
829                funcs.push(key);
830            }
831
832            // Sort/dedup our list of `funcs` to satisfy the requirement of
833            // `CompiledFunctionsTableBuilder::push_func`.
834            funcs.sort();
835            funcs.dedup();
836
837            let mut builder = CompiledFunctionsTableBuilder::new();
838            let mut size = 0;
839            let mut expected = Vec::new();
840            for key in funcs {
841                let length = u.int_in_range(1..=10)?;
842                for _ in 0..length {
843                    expected.push(key);
844                }
845                // println!("push {key:?} - {length}");
846                builder.push_func(
847                    key,
848                    FunctionLoc {
849                        start: size,
850                        length,
851                    },
852                    FilePos::none(),
853                );
854                size += length;
855            }
856            let index = builder.finish();
857
858            let mut expected = expected.iter();
859            for i in 0..size {
860                // println!("lookup {i}");
861                let actual = index.func_by_text_offset(i).unwrap();
862                assert_eq!(Some(&actual), expected.next());
863            }
864
865            Ok(())
866        }
867
868        fn idx<T>(u: &mut Unstructured<'_>, max: usize) -> Result<T>
869        where
870            T: EntityRef,
871        {
872            Ok(T::new(u.int_in_range(0..=max - 1)?))
873        }
874    }
875}
wasmtime_environ/module_artifacts.rs

wasmtime_environ/
module_artifacts.rs
