wip2

Author: hvitved

rust/ql/lib/codeql/rust/internal/typeinference/FunctionType.qll

@@ -29,18 +29,20 @@ class FunctionPosition extends TFunctionPosition {
 
   predicate isReturn() { this = TReturnFunctionPosition() }
 
-  /** Gets the corresponding position when `f` is invoked via a function call. */
-  bindingset[f]
-  FunctionPosition getFunctionCallAdjusted(Function f) {
+  /** Gets the corresponding position when function call syntax is used. */
+  FunctionPosition getFunctionCallAdjusted() {
     (this.isReturn() or this.isTypeQualifier()) and
     result = this
     or
-    if f.hasSelfParam()
-    then
-      this.isSelf() and result.asPosition() = 0
-      or
-      result.asPosition() = this.asPosition() + 1
-    else result = this
+    this.isSelf() and result.asPosition() = 0
+    or
+    result.asPosition() = this.asPosition() + 1
+  }
+
+  /** Gets the corresponding position when `f` is invoked via a function call. */
+  bindingset[f]
+  FunctionPosition getFunctionCallAdjusted(Function f) {
+    if f.hasSelfParam() then result = this.getFunctionCallAdjusted() else result = this
   }
 
   TypeMention getTypeMention(Function f) {

rust/ql/lib/codeql/rust/internal/typeinference/TypeInference.qll

@@ -1394,16 +1394,22 @@ private module AssocFunctionResolution {
 
   /**
    * Holds if function `f` with the name `name` and the arity `arity` exists in
-   * `i`, and the type of the `self` parameter is `selfType`.
+   * `i`, and the type at `selfPos` and `strippedTypePath` is `selfType`.
+   *
+   * `selfPos` is one of the positions that can be used to resolve the call, for
+   * example the `self` parameter of a method or a position corresponding to `Self`
+   * trait type parameter.
    *
    * `strippedTypePath` points to the type `strippedType` inside `selfType`,
    * which is the (possibly complex-stripped) root type of `selfType`. For example,
    * if `f` has a `&self` parameter, then `strippedTypePath` is `getRefSharedTypeParameter()`
    * and `strippedType` is the type inside the reference.
+   *
+   * `selfPosAdj` is the function-call adjusted version of `selfPos`.
    */
   pragma[nomagic]
   private predicate assocFunctionInfo(
-    Function f, string name, int arity, FunctionPosition selfPos, FunctionPosition posAdj,
+    Function f, string name, int arity, FunctionPosition selfPos, FunctionPosition selfPosAdj,
     ImplOrTraitItemNode i, AssocFunctionType selfType, TypePath strippedTypePath, Type strippedType
   ) {
     assocFunctionInfo(f, name, arity, i, selfPos, selfType) and
@@ -1413,7 +1419,7 @@ private module AssocFunctionResolution {
       or
       selfPos.isTypeQualifier() and strippedTypePath.isEmpty()
     ) and
-    posAdj = selfPos.getFunctionCallAdjusted(f) and
+    selfPosAdj = selfPos.getFunctionCallAdjusted(f) and
     (
       selfPos.isSelfOrTypeQualifier()
       or
@@ -1425,10 +1431,10 @@ private module AssocFunctionResolution {
 
   pragma[nomagic]
   private predicate assocFunctionInfoTypeParam(
-    Function f, string name, int arity, FunctionPosition selfPos, FunctionPosition posAdj,
+    Function f, string name, int arity, FunctionPosition selfPos, FunctionPosition selfPosAdj,
     ImplOrTraitItemNode i, AssocFunctionType selfType, TypePath strippedTypePath, TypeParam tp
   ) {
-    assocFunctionInfo(f, name, arity, selfPos, posAdj, i, selfType, strippedTypePath,
+    assocFunctionInfo(f, name, arity, selfPos, selfPosAdj, i, selfType, strippedTypePath,
       TTypeParamTypeParameter(tp))
   }
 
@@ -1439,33 +1445,35 @@ private module AssocFunctionResolution {
    */
   pragma[inline]
   private predicate assocFunctionInfoNonBlanket(
-    Function f, string name, int arity, FunctionPosition selfPos, FunctionPosition posAdj,
+    Function f, string name, int arity, FunctionPosition selfPos, FunctionPosition selfPosAdj,
     ImplOrTraitItemNode i, AssocFunctionType selfType, TypePath strippedTypePath, Type strippedType
   ) {
     (
-      assocFunctionInfo(f, name, arity, selfPos, posAdj, i, selfType, strippedTypePath, strippedType) or
-      assocFunctionInfoTypeParam(f, name, arity, selfPos, posAdj, i, selfType, strippedTypePath, _)
+      assocFunctionInfo(f, name, arity, selfPos, selfPosAdj, i, selfType, strippedTypePath,
+        strippedType) or
+      assocFunctionInfoTypeParam(f, name, arity, selfPos, selfPosAdj, i, selfType, strippedTypePath,
+        _)
     ) and
     not BlanketImplementation::isBlanketLike(i, _, _)
   }
 
   /**
-   * Holds if function `f` with the name `name` and the arity `arity` exists in
-   * blanket (like) implementation `impl` of `trait`, and the type of the `self`
-   * parameter is `selfType`.
+   * Holds if associated function `f` with the name `name` and the arity `arity` exists
+   * in blanket (like) implementation `impl` of `trait`, and the type at `selfPos` and
+   * `blanketPath` is `selfType`.
    *
    * `blanketPath` points to the type `blanketTypeParam` inside `selfType`, which
    * is the type parameter used in the blanket implementation.
    */
   pragma[nomagic]
   private predicate assocFunctionSelfInfoBlanketLike(
-    Function f, string name, int arity, FunctionPosition selfPos, FunctionPosition posAdj,
+    Function f, string name, int arity, FunctionPosition selfPos, FunctionPosition selfPosAdj,
     ImplItemNode impl, Trait trait, AssocFunctionType selfType, TypePath blanketPath,
     TypeParam blanketTypeParam
   ) {
     assocFunctionInfoBlanketLike(f, name, arity, impl, trait, selfPos, selfType, blanketPath,
       blanketTypeParam) and
-    posAdj = selfPos.getFunctionCallAdjusted(f) and
+    selfPosAdj = selfPos.getFunctionCallAdjusted(f) and
     (
       selfPos.isSelfOrTypeQualifier()
       or
@@ -1522,12 +1530,12 @@ private module AssocFunctionResolution {
   bindingset[mc, strippedTypePath, strippedType]
   pragma[inline_late]
   private predicate methodCallNonBlanketCandidate(
-    MethodCall mc, Function f, FunctionPosition selfPos, FunctionPosition pos,
+    MethodCall mc, Function f, FunctionPosition selfPos, FunctionPosition selfPosAdj,
     ImplOrTraitItemNode i, AssocFunctionType self, TypePath strippedTypePath, Type strippedType
   ) {
     exists(string name, int arity |
       mc.hasNameAndArity(name, arity) and
-      assocFunctionInfoNonBlanket(f, name, arity, selfPos, pos, i, self, strippedTypePath,
+      assocFunctionInfoNonBlanket(f, name, arity, selfPos, selfPosAdj, i, self, strippedTypePath,
         strippedType) and
       (if mc.hasReceiver() then f instanceof Method else any()) and
       // todo: comment
@@ -1565,13 +1573,13 @@ private module AssocFunctionResolution {
   bindingset[mc]
   pragma[inline_late]
   private predicate methodCallBlanketLikeCandidate(
-    MethodCall mc, Function f, FunctionPosition selfPos, FunctionPosition pos, ImplItemNode impl,
-    AssocFunctionType self, TypePath blanketPath, TypeParam blanketTypeParam
+    MethodCall mc, Function f, FunctionPosition selfPos, FunctionPosition selfPosAdj,
+    ImplItemNode impl, AssocFunctionType self, TypePath blanketPath, TypeParam blanketTypeParam
   ) {
     exists(string name, int arity |
       mc.hasNameAndArity(name, arity) and
-      assocFunctionSelfInfoBlanketLike(f, name, arity, selfPos, pos, impl, _, self, blanketPath,
-        blanketTypeParam) and
+      assocFunctionSelfInfoBlanketLike(f, name, arity, selfPos, selfPosAdj, impl, _, self,
+        blanketPath, blanketTypeParam) and
       if mc.hasReceiver() then f instanceof Method else any()
     |
       methodCallVisibleImplTraitCandidate(mc, impl)
@@ -2005,10 +2013,10 @@ private module AssocFunctionResolution {
      */
     pragma[nomagic]
     Function resolveCallTarget(
-      ImplOrTraitItemNode i, FunctionPosition pos, DerefChain derefChain, BorrowKind borrow
+      ImplOrTraitItemNode i, FunctionPosition selfPos, DerefChain derefChain, BorrowKind borrow
     ) {
       exists(MethodCallCand mcc |
-        mcc = MkMethodCallCand(this, pos, _, derefChain, borrow) and
+        mcc = MkMethodCallCand(this, selfPos, _, derefChain, borrow) and
         result = mcc.resolveCallTarget(i)
       )
     }
@@ -2171,32 +2179,25 @@ private module AssocFunctionResolution {
 
   private newtype TMethodCallCand =
     MkMethodCallCand(
-      MethodCall mc, FunctionPosition selfPos, FunctionPosition pos, DerefChain derefChain,
+      MethodCall mc, FunctionPosition selfPos, FunctionPosition selfPosAdj, DerefChain derefChain,
       BorrowKind borrow
     ) {
       // todo: restrict to relevant positions
       exists(mc.getACandidateReceiverTypeAt(selfPos, derefChain, borrow, _)) and
       if mc.hasReceiver()
-      then
-        pos.asPosition() = 0 and selfPos.isSelf()
-        or
-        pos.asPosition() = selfPos.asPosition() + 1
-        or
-        pos.isTypeQualifier() and selfPos.isTypeQualifier()
-        or
-        pos.isReturn() and selfPos.isReturn()
-      else pos = selfPos
+      then selfPosAdj = selfPos.getFunctionCallAdjusted()
+      else selfPosAdj = selfPos
     }
 
   /** A method call with a dereference chain and a potential borrow. */
   private class MethodCallCand extends MkMethodCallCand {
     MethodCall mc_;
-    FunctionPosition pos;
     FunctionPosition selfPos;
+    FunctionPosition selfPosAdj;
     DerefChain derefChain;
     BorrowKind borrow;
 
-    MethodCallCand() { this = MkMethodCallCand(mc_, selfPos, pos, derefChain, borrow) }
+    MethodCallCand() { this = MkMethodCallCand(mc_, selfPos, selfPosAdj, derefChain, borrow) }
 
     MethodCall getMethodCall() { result = mc_ }
 
@@ -2220,7 +2221,7 @@ private module AssocFunctionResolution {
 
     pragma[nomagic]
     predicate hasSignature(
-      MethodCall mc, FunctionPosition pos_, TypePath strippedTypePath, Type strippedType,
+      MethodCall mc, FunctionPosition pos, TypePath strippedTypePath, Type strippedType,
       string name, int arity
     ) {
       strippedType = this.getTypeAt(strippedTypePath) and
@@ -2231,7 +2232,7 @@ private module AssocFunctionResolution {
       ) and
       mc = mc_ and
       mc.hasNameAndArity(name, arity) and
-      pos = pos_
+      pos = selfPosAdj
     }
 
     /**
@@ -2252,10 +2253,11 @@ private module AssocFunctionResolution {
       mc_.hasTrait()
       or
       exists(TypePath strippedTypePath, Type strippedType, string name, int arity |
-        (pos.isTypeQualifier() or pos.asPosition() = 0) and
-        this.hasSignature(_, pos, strippedTypePath, strippedType, name, arity) and
+        (selfPosAdj.isTypeQualifier() or selfPosAdj.asPosition() = 0) and
+        this.hasSignature(_, selfPosAdj, strippedTypePath, strippedType, name, arity) and
         forall(Impl i |
-          assocFunctionInfoNonBlanket(_, name, arity, _, pos, i, _, strippedTypePath, strippedType) and
+          assocFunctionInfoNonBlanket(_, name, arity, _, selfPosAdj, i, _, strippedTypePath,
+            strippedType) and
           not i.hasTrait()
         |
           this.hasIncompatibleInherentTarget(i)
@@ -2287,7 +2289,8 @@ private module AssocFunctionResolution {
     }
 
     string toString() {
-      result = mc_.toString() + " at " + pos + " [" + derefChain.toString() + "; " + borrow + "]"
+      result =
+        mc_.toString() + " at " + selfPos + " [" + derefChain.toString() + "; " + borrow + "]"
     }
 
     Location getLocation() { result = mc_.getLocation() }
@@ -2368,9 +2371,9 @@ private module AssocFunctionResolution {
     predicate hasBlanketCandidate(
       MethodCallCand mcc, ImplItemNode impl, TypePath blanketPath, TypeParam blanketTypeParam
     ) {
-      exists(MethodCall mc, FunctionPosition pos, BorrowKind borrow |
-        mcc = MkMethodCallCand(mc, _, pos, _, borrow) and
-        methodCallBlanketLikeCandidate(mc, _, _, pos, impl, _, blanketPath, blanketTypeParam) and
+      exists(MethodCall mc, FunctionPosition selfPosAdj, BorrowKind borrow |
+        mcc = MkMethodCallCand(mc, _, selfPosAdj, _, borrow) and
+        methodCallBlanketLikeCandidate(mc, _, _, selfPosAdj, impl, _, blanketPath, blanketTypeParam) and
         // Only apply blanket implementations when no other implementations are possible;
         // this is to account for codebases that use the (unstable) specialization feature
         // (https://rust-lang.github.io/rfcs/1210-impl-specialization.html), as well as
@@ -2444,9 +2447,9 @@ private module AssocFunctionResolution {
     predicate potentialInstantiationOf(
       MethodCallCand mcc, TypeAbstraction abs, AssocFunctionType constraint
     ) {
-      exists(MethodCall mc, FunctionPosition pos |
-        mcc = MkMethodCallCand(mc, _, pos, _, _) and
-        methodCallBlanketLikeCandidate(mc, _, _, pos, abs, constraint, _, _) and
+      exists(MethodCall mc, FunctionPosition selfPosAdj |
+        mcc = MkMethodCallCand(mc, _, selfPosAdj, _, _) and
+        methodCallBlanketLikeCandidate(mc, _, _, selfPosAdj, abs, constraint, _, _) and
         if abs.(Impl).hasTrait()
         then
           // inherent methods take precedence over trait methods, so only allow
@@ -2474,8 +2477,8 @@ private module AssocFunctionResolution {
       ReceiverIsInstantiationOfSelfParamInput::potentialInstantiationOf0(mcc, abs, constraint) and
       abs = any(Impl i | not i.hasTrait()) and
       // todo: comment
-      exists(FunctionPosition pos | mcc = MkMethodCallCand(_, _, pos, _, _) |
-        pos.isTypeQualifier() or pos.asPosition() = 0
+      exists(FunctionPosition selfPosAdj | mcc = MkMethodCallCand(_, _, selfPosAdj, _, _) |
+        selfPosAdj.isTypeQualifier() or selfPosAdj.asPosition() = 0
       )
     }
   }
@@ -2623,17 +2626,7 @@ private module MethodCallMatchingInput implements MatchingWithEnvironmentInputSi
         )
       |
         // result = this.getInferredNonSelfType(pos, path)
-        if this.hasReceiver()
-        then apos = pos
-        else (
-          pos.asPosition() = 0 and apos.isSelf()
-          or
-          pos.asPosition() = apos.asPosition() + 1
-          or
-          pos.isTypeQualifier() and apos.isTypeQualifier()
-          or
-          pos.isReturn() and apos.isReturn()
-        )
+        if this.hasReceiver() then apos = pos else pos = apos.getFunctionCallAdjusted()
       )
     }
 
@@ -2689,17 +2682,7 @@ private Type inferMethodCallType0(
   exists(TypePath path0 |
     n = a.getNodeAt(apos) and
     exists(FunctionPosition pos |
-      if a.hasReceiver()
-      then apos = pos
-      else (
-        apos.asPosition() = 0 and pos.isSelf()
-        or
-        apos.asPosition() = pos.asPosition() + 1
-        or
-        apos.isTypeQualifier() and pos.isTypeQualifier()
-        or
-        apos.isReturn() and pos.isReturn()
-      )
+      if a.hasReceiver() then apos = pos else apos = pos.getFunctionCallAdjusted()
     |
       exists(string derefChainBorrow |
         MethodCallMatchingInput::decodeDerefChainBorrow(derefChainBorrow, _, derefChain, borrow)