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Rust: Model async return types as dyn Future #20236

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57 changes: 42 additions & 15 deletions rust/ql/lib/codeql/rust/internal/Type.qll
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Original file line number Diff line number Diff line change
Expand Up @@ -82,14 +82,22 @@ abstract class Type extends TType {
pragma[nomagic]
abstract TupleField getTupleField(int i);

/** Gets the `i`th type parameter of this type, if any. */
abstract TypeParameter getTypeParameter(int i);
/**
* Gets the `i`th positional type parameter of this type, if any.
*
* This excludes for example associated type parameters.
*/
abstract TypeParameter getPositionalTypeParameter(int i);

/** Gets the default type for the `i`th type parameter, if any. */
TypeMention getTypeParameterDefault(int i) { none() }

/** Gets a type parameter of this type. */
final TypeParameter getATypeParameter() { result = this.getTypeParameter(_) }
/**
* Gets a type parameter of this type.
*
* This includes both positional and other type parameters, such as associated types.
*/
TypeParameter getATypeParameter() { result = this.getPositionalTypeParameter(_) }

/** Gets a textual representation of this type. */
abstract string toString();
Expand All @@ -108,7 +116,9 @@ class TupleType extends Type, TTuple {

override TupleField getTupleField(int i) { none() }

override TypeParameter getTypeParameter(int i) { result = TTupleTypeParameter(arity, i) }
override TypeParameter getPositionalTypeParameter(int i) {
result = TTupleTypeParameter(arity, i)
}

/** Gets the arity of this tuple type. */
int getArity() { result = arity }
Expand Down Expand Up @@ -141,7 +151,7 @@ class StructType extends StructOrEnumType, TStruct {

override TupleField getTupleField(int i) { result = struct.getTupleField(i) }

override TypeParameter getTypeParameter(int i) {
override TypeParameter getPositionalTypeParameter(int i) {
result = TTypeParamTypeParameter(struct.getGenericParamList().getTypeParam(i))
}

Expand All @@ -166,7 +176,7 @@ class EnumType extends StructOrEnumType, TEnum {

override TupleField getTupleField(int i) { none() }

override TypeParameter getTypeParameter(int i) {
override TypeParameter getPositionalTypeParameter(int i) {
result = TTypeParamTypeParameter(enum.getGenericParamList().getTypeParam(i))
}

Expand All @@ -192,10 +202,18 @@ class TraitType extends Type, TTrait {

override TupleField getTupleField(int i) { none() }

override TypeParameter getTypeParameter(int i) {
override TypeParameter getPositionalTypeParameter(int i) {
result = TTypeParamTypeParameter(trait.getGenericParamList().getTypeParam(i))
}

override TypeParameter getATypeParameter() {
result = super.getATypeParameter()
or
result.(AssociatedTypeTypeParameter).getTrait() = trait
or
result.(SelfTypeParameter).getTrait() = trait
}

override TypeMention getTypeParameterDefault(int i) {
result = trait.getGenericParamList().getTypeParam(i).getDefaultType()
}
Expand All @@ -218,7 +236,7 @@ class ArrayType extends Type, TArrayType {

override TupleField getTupleField(int i) { none() }

override TypeParameter getTypeParameter(int i) {
override TypeParameter getPositionalTypeParameter(int i) {
result = TArrayTypeParameter() and
i = 0
}
Expand All @@ -241,7 +259,7 @@ class RefType extends Type, TRefType {

override TupleField getTupleField(int i) { none() }

override TypeParameter getTypeParameter(int i) {
override TypeParameter getPositionalTypeParameter(int i) {
result = TRefTypeParameter() and
i = 0
}
Expand Down Expand Up @@ -274,7 +292,7 @@ class ImplTraitType extends Type, TImplTraitType {

override TupleField getTupleField(int i) { none() }

override TypeParameter getTypeParameter(int i) {
override TypeParameter getPositionalTypeParameter(int i) {
exists(TypeParam tp |
implTraitTypeParam(impl, i, tp) and
result = TImplTraitTypeParameter(impl, tp)
Expand All @@ -295,10 +313,19 @@ class DynTraitType extends Type, TDynTraitType {

override TupleField getTupleField(int i) { none() }

override DynTraitTypeParameter getTypeParameter(int i) {
override DynTraitTypeParameter getPositionalTypeParameter(int i) {
result = TDynTraitTypeParameter(trait.getGenericParamList().getTypeParam(i))
}

override TypeParameter getATypeParameter() {
result = super.getATypeParameter()
or
exists(AstNode n |
dynTraitTypeParameter(trait, n) and
result = TDynTraitTypeParameter(n)
)
}

Trait getTrait() { result = trait }

override string toString() { result = "dyn " + trait.getName().toString() }
Expand Down Expand Up @@ -336,7 +363,7 @@ class SliceType extends Type, TSliceType {

override TupleField getTupleField(int i) { none() }

override TypeParameter getTypeParameter(int i) {
override TypeParameter getPositionalTypeParameter(int i) {
result = TSliceTypeParameter() and
i = 0
}
Expand All @@ -352,7 +379,7 @@ abstract class TypeParameter extends Type {

override TupleField getTupleField(int i) { none() }

override TypeParameter getTypeParameter(int i) { none() }
override TypeParameter getPositionalTypeParameter(int i) { none() }
}

private class RawTypeParameter = @type_param or @trait or @type_alias or @impl_trait_type_repr;
Expand Down Expand Up @@ -548,7 +575,7 @@ class ImplTraitTypeTypeParameter extends ImplTraitType, TypeParameter {

override TupleField getTupleField(int i) { none() }

override TypeParameter getTypeParameter(int i) { none() }
override TypeParameter getPositionalTypeParameter(int i) { none() }
}

/**
Expand Down
23 changes: 15 additions & 8 deletions rust/ql/lib/codeql/rust/internal/TypeInference.qll
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Expand Up @@ -374,6 +374,9 @@ private module CertainTypeInference {
or
result = inferLiteralType(n, path, true)
or
result = inferAsyncBlockExprRootType(n) and
path.isEmpty()
or
infersCertainTypeAt(n, path, result.getATypeParameter())
}

Expand Down Expand Up @@ -521,7 +524,7 @@ private predicate typeEquality(AstNode n1, TypePath prefix1, AstNode n2, TypePat
n2 = be.getStmtList().getTailExpr() and
if be.isAsync()
then
prefix1 = TypePath::singleton(getFutureOutputTypeParameter()) and
prefix1 = TypePath::singleton(getDynFutureOutputTypeParameter()) and
prefix2.isEmpty()
else (
prefix1.isEmpty() and
Expand Down Expand Up @@ -941,7 +944,7 @@ private module CallExprBaseMatchingInput implements MatchingInputSig {
or
exists(TypePath suffix |
result = this.resolveRetType(suffix) and
path = TypePath::cons(getFutureOutputTypeParameter(), suffix)
path = TypePath::cons(getDynFutureOutputTypeParameter(), suffix)
)
else result = this.resolveRetType(path)
}
Expand Down Expand Up @@ -1427,16 +1430,22 @@ private Type inferLiteralType(LiteralExpr le, TypePath path, boolean certain) {
certain = true
}

// always exists because of the mention in `builtins/mentions.rs`
pragma[nomagic]
private TraitType getFutureTraitType() { result.getTrait() instanceof FutureTrait }
private DynTraitType getFutureTraitType() { result.getTrait() instanceof FutureTrait }

pragma[nomagic]
private AssociatedTypeTypeParameter getFutureOutputTypeParameter() {
result.getTypeAlias() = any(FutureTrait ft).getOutputType()
}

pragma[nomagic]
private TraitType inferAsyncBlockExprRootType(AsyncBlockExpr abe) {
private DynTraitTypeParameter getDynFutureOutputTypeParameter() {
result = TDynTraitTypeParameter(any(FutureTrait ft).getOutputType())
}

pragma[nomagic]
private DynTraitType inferAsyncBlockExprRootType(AsyncBlockExpr abe) {
// `typeEquality` handles the non-root case
exists(abe) and
result = getFutureTraitType()
Expand All @@ -1449,6 +1458,7 @@ final private class AwaitTarget extends Expr {
}

private module AwaitSatisfiesConstraintInput implements SatisfiesConstraintInputSig<AwaitTarget> {
pragma[nomagic]
predicate relevantConstraint(AwaitTarget term, Type constraint) {
exists(term) and
constraint.(TraitType).getTrait() instanceof FutureTrait
Expand Down Expand Up @@ -1774,7 +1784,7 @@ private Type inferClosureExprType(AstNode n, TypePath path) {
exists(ClosureExpr ce |
n = ce and
path.isEmpty() and
result = TDynTraitType(any(FnOnceTrait t))
result = TDynTraitType(any(FnOnceTrait t)) // always exists because of the mention in `builtins/mentions.rs`
or
n = ce and
path = TypePath::singleton(TDynTraitTypeParameter(any(FnOnceTrait t).getTypeParam())) and
Expand Down Expand Up @@ -2382,9 +2392,6 @@ private module Cached {
or
result = inferLiteralType(n, path, false)
or
result = inferAsyncBlockExprRootType(n) and
path.isEmpty()
or
result = inferAwaitExprType(n, path)
or
result = inferArrayExprType(n) and
Expand Down
2 changes: 1 addition & 1 deletion rust/ql/lib/codeql/rust/internal/TypeMention.qll
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Expand Up @@ -182,7 +182,7 @@ class NonAliasPathTypeMention extends PathTypeMention {
private TypeMention getTypeMentionForTypeParameter(TypeParameter tp) {
exists(int i |
result = this.getPositionalTypeArgument(pragma[only_bind_into](i)) and
tp = this.resolveRootType().getTypeParameter(pragma[only_bind_into](i))
tp = this.resolveRootType().getPositionalTypeParameter(pragma[only_bind_into](i))
)
or
exists(TypeAlias alias |
Expand Down
23 changes: 11 additions & 12 deletions rust/ql/test/library-tests/type-inference/type-inference.expected
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Expand Up @@ -3728,9 +3728,8 @@ inferType
| main.rs:1915:25:1917:5 | { ... } | | main.rs:1909:5:1909:14 | S1 |
| main.rs:1916:9:1916:10 | S1 | | main.rs:1909:5:1909:14 | S1 |
| main.rs:1919:41:1921:5 | { ... } | | main.rs:1919:16:1919:39 | ImplTraitTypeRepr |
| main.rs:1920:9:1920:20 | { ... } | | {EXTERNAL LOCATION} | trait Future |
| main.rs:1920:9:1920:20 | { ... } | | main.rs:1919:16:1919:39 | ImplTraitTypeRepr |
| main.rs:1920:9:1920:20 | { ... } | Output | main.rs:1909:5:1909:14 | S1 |
| main.rs:1920:9:1920:20 | { ... } | | {EXTERNAL LOCATION} | dyn Future |
| main.rs:1920:9:1920:20 | { ... } | dyn(Output) | main.rs:1909:5:1909:14 | S1 |
| main.rs:1920:17:1920:18 | S1 | | main.rs:1909:5:1909:14 | S1 |
| main.rs:1929:13:1929:42 | SelfParam | | {EXTERNAL LOCATION} | Pin |
| main.rs:1929:13:1929:42 | SelfParam | Ptr | file://:0:0:0:0 | & |
Expand All @@ -3745,22 +3744,22 @@ inferType
| main.rs:1936:41:1938:5 | { ... } | | main.rs:1936:16:1936:39 | ImplTraitTypeRepr |
| main.rs:1937:9:1937:10 | S2 | | main.rs:1923:5:1923:14 | S2 |
| main.rs:1937:9:1937:10 | S2 | | main.rs:1936:16:1936:39 | ImplTraitTypeRepr |
| main.rs:1941:9:1941:12 | f1(...) | | {EXTERNAL LOCATION} | trait Future |
| main.rs:1941:9:1941:12 | f1(...) | Output | main.rs:1909:5:1909:14 | S1 |
| main.rs:1941:9:1941:12 | f1(...) | | {EXTERNAL LOCATION} | dyn Future |
| main.rs:1941:9:1941:12 | f1(...) | dyn(Output) | main.rs:1909:5:1909:14 | S1 |
| main.rs:1941:9:1941:18 | await ... | | main.rs:1909:5:1909:14 | S1 |
| main.rs:1942:9:1942:12 | f2(...) | | main.rs:1919:16:1919:39 | ImplTraitTypeRepr |
| main.rs:1942:9:1942:18 | await ... | | main.rs:1909:5:1909:14 | S1 |
| main.rs:1943:9:1943:12 | f3(...) | | main.rs:1936:16:1936:39 | ImplTraitTypeRepr |
| main.rs:1943:9:1943:18 | await ... | | main.rs:1909:5:1909:14 | S1 |
| main.rs:1944:9:1944:10 | S2 | | main.rs:1923:5:1923:14 | S2 |
| main.rs:1944:9:1944:16 | await S2 | | main.rs:1909:5:1909:14 | S1 |
| main.rs:1945:13:1945:13 | b | | {EXTERNAL LOCATION} | trait Future |
| main.rs:1945:13:1945:13 | b | Output | main.rs:1909:5:1909:14 | S1 |
| main.rs:1945:17:1945:28 | { ... } | | {EXTERNAL LOCATION} | trait Future |
| main.rs:1945:17:1945:28 | { ... } | Output | main.rs:1909:5:1909:14 | S1 |
| main.rs:1945:13:1945:13 | b | | {EXTERNAL LOCATION} | dyn Future |
| main.rs:1945:13:1945:13 | b | dyn(Output) | main.rs:1909:5:1909:14 | S1 |
| main.rs:1945:17:1945:28 | { ... } | | {EXTERNAL LOCATION} | dyn Future |
| main.rs:1945:17:1945:28 | { ... } | dyn(Output) | main.rs:1909:5:1909:14 | S1 |
| main.rs:1945:25:1945:26 | S1 | | main.rs:1909:5:1909:14 | S1 |
| main.rs:1946:9:1946:9 | b | | {EXTERNAL LOCATION} | trait Future |
| main.rs:1946:9:1946:9 | b | Output | main.rs:1909:5:1909:14 | S1 |
| main.rs:1946:9:1946:9 | b | | {EXTERNAL LOCATION} | dyn Future |
| main.rs:1946:9:1946:9 | b | dyn(Output) | main.rs:1909:5:1909:14 | S1 |
| main.rs:1946:9:1946:15 | await b | | main.rs:1909:5:1909:14 | S1 |
| main.rs:1957:15:1957:19 | SelfParam | | file://:0:0:0:0 | & |
| main.rs:1957:15:1957:19 | SelfParam | &T | main.rs:1956:5:1958:5 | Self [trait Trait1] |
Expand Down Expand Up @@ -4992,7 +4991,7 @@ inferType
| main.rs:2613:5:2613:60 | ...::g(...) | | main.rs:72:5:72:21 | Foo |
| main.rs:2613:20:2613:38 | ...::Foo {...} | | main.rs:72:5:72:21 | Foo |
| main.rs:2613:41:2613:59 | ...::Foo {...} | | main.rs:72:5:72:21 | Foo |
| main.rs:2629:5:2629:15 | ...::f(...) | | {EXTERNAL LOCATION} | trait Future |
| main.rs:2629:5:2629:15 | ...::f(...) | | {EXTERNAL LOCATION} | dyn Future |
| pattern_matching.rs:13:26:133:1 | { ... } | | {EXTERNAL LOCATION} | Option |
| pattern_matching.rs:13:26:133:1 | { ... } | T | file://:0:0:0:0 | () |
| pattern_matching.rs:14:9:14:13 | value | | {EXTERNAL LOCATION} | Option |
Expand Down
6 changes: 6 additions & 0 deletions rust/tools/builtins/mentions.rs
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Original file line number Diff line number Diff line change
@@ -0,0 +1,6 @@
// Type mentions required by type inference

use std::future::Future;
fn mention_dyn_future<T>(f: &dyn Future<Output = T>) {}

Check notice

Code scanning / CodeQL

Unused variable Note

Variable 'f' is not used.

fn mention_dyn_fn_once<F>(f: &dyn FnOnce() -> F) {}

Check notice

Code scanning / CodeQL

Unused variable Note

Variable 'f' is not used.
3 changes: 0 additions & 3 deletions shared/typeinference/codeql/typeinference/internal/TypeInference.qll
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Expand Up @@ -1007,9 +1007,6 @@ module Make1<LocationSig Location, InputSig1<Location> Input1> {
tt.getTypeAt(pathToTypeParamInSub.appendInverse(suffix)) = t and
path = prefix0.append(suffix)
)
or
hasTypeConstraint(tt, constraint, constraint) and
t = tt.getTypeAt(path)
}
}

Expand Down
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