wip6

Author: hvitved

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

@@ -434,7 +434,7 @@ private module Input3 implements InputSig3 {
   }
 
   bindingset[derefChainBorrow]
-  Type inferCallTypeBottomUp(Call call, string derefChainBorrow, FunctionPosition pos, TypePath path) {
+  Type inferCallTypeAtPos(Call call, string derefChainBorrow, FunctionPosition pos, TypePath path) {
     result = call.(FunctionCallMatchingInput::Access).getInferredType(derefChainBorrow, pos, path)
   }
 
@@ -450,14 +450,14 @@ private module Input3 implements InputSig3 {
     )
   }
 
-  Type inferCallArgumentTypeTopDown(AstNode n, TypePath path) {
+  Type inferCallArgumentType(AstNode n, TypePath path) {
     exists(FunctionCallMatchingInput::Access call, FunctionPosition pos |
-      result = inferCallArgumentTypeTopDown(call, pos, n, _, _, path) and
+      result = inferCallArgumentType(call, pos, n, _, _, path) and
       not call.(AssocFunctionResolution::AssocFunctionCall).hasReceiverAtPos(pos)
     )
     or
     exists(FunctionCallMatchingInput::Access a |
-      result = inferFunctionCallSelfArgumentTypeTopDown(a, n, DerefChain::nil(), path) and
+      result = inferFunctionCallSelfArgumentType(a, n, DerefChain::nil(), path) and
       if a.(AssocFunctionResolution::AssocFunctionCall).hasReceiver()
       then not path.isEmpty()
       else any()
@@ -623,20 +623,6 @@ private module Input3 implements InputSig3 {
     )
   }
 
-  Type inferTypeTopDown(AstNode n, TypePath path) {
-    result = inferTypeFromAnnotationTopDown(n, path)
-    or
-    result = inferClosureExprBodyTypeTopDown(n, path)
-    or
-    exists(FunctionPosition pos | not pos.isReturn() |
-      result = inferConstructionType(n, pos, path)
-      or
-      result = inferOperationType(n, pos, path)
-    )
-    or
-    result = inferFieldExprType(n, path, true)
-  }
-
   Type inferType(AstNode n, TypePath path) {
     result = M3::inferType(n, path)
     or
@@ -672,6 +658,20 @@ private module Input3 implements InputSig3 {
     or
     result = inferUnknownType(n, path)
   }
+
+  Type inferTypeTopDown(AstNode n, TypePath path) {
+    result = inferTypeFromAnnotationTopDown(n, path)
+    or
+    result = inferClosureExprBodyTypeTopDown(n, path)
+    or
+    exists(FunctionPosition pos | not pos.isReturn() |
+      result = inferConstructionType(n, pos, path)
+      or
+      result = inferOperationType(n, pos, path)
+    )
+    or
+    result = inferFieldExprType(n, path, true)
+  }
 }
 
 private module M3 = Make3<Input3>;
@@ -2827,13 +2827,13 @@ private module FunctionCallMatchingInput implements MatchingWithEnvironmentInput
 }
 
 pragma[nomagic]
-private Type inferCallArgumentTypeTopDown(
+private Type inferCallArgumentType(
   FunctionCallMatchingInput::Access call, FunctionPosition pos, AstNode n, DerefChain derefChain,
   BorrowKind borrow, TypePath path
 ) {
   exists(string derefChainBorrow |
     FunctionCallMatchingInput::decodeDerefChainBorrow(derefChainBorrow, derefChain, borrow) and
-    result = M3::inferCallArgumentTypeTopDown(call, derefChainBorrow, pos, n, path)
+    result = M3::inferCallArgumentType(call, derefChainBorrow, pos, n, path)
   )
 }
 
@@ -2845,12 +2845,12 @@ private Type inferCallArgumentTypeTopDown(
  * empty, at which point the inferred type can be applied back to `n`.
  */
 pragma[nomagic]
-private Type inferFunctionCallSelfArgumentTypeTopDown(
+private Type inferFunctionCallSelfArgumentType(
   FunctionCallMatchingInput::Access call, AstNode n, DerefChain derefChain, TypePath path
 ) {
   exists(FunctionPosition pos, BorrowKind borrow, TypePath path0 |
     call.(AssocFunctionResolution::AssocFunctionCall).hasReceiverAtPos(pos) and
-    result = inferCallArgumentTypeTopDown(call, pos, n, derefChain, borrow, path0)
+    result = inferCallArgumentType(call, pos, n, derefChain, borrow, path0)
   |
     borrow.isNoBorrow() and
     path = path0
@@ -2867,7 +2867,7 @@ private Type inferFunctionCallSelfArgumentTypeTopDown(
     DerefChain derefChain0, Type t0, TypePath path0, DerefImplItemNode impl, Type selfParamType,
     TypePath selfPath
   |
-    t0 = inferFunctionCallSelfArgumentTypeTopDown(call, n, derefChain0, path0) and
+    t0 = inferFunctionCallSelfArgumentType(call, n, derefChain0, path0) and
     derefChain0.isCons(impl, derefChain) and
     selfParamType = impl.resolveSelfTypeAt(selfPath)
   |

shared/typeinference/codeql/typeinference/internal/TypeInference.qll

@@ -2251,7 +2251,7 @@ module Make1<LocationSig Location, InputSig1<Location> Input1> {
        * about the call via the call target, such as the return type.
        */
       bindingset[ctx]
-      default Type inferCallTypeBottomUp(
+      default Type inferCallTypeAtPos(
         Call call, CallResolutionContext ctx, TypePosition pos, TypePath path
       ) {
         result = inferType(call.getNodeAt(pos), path) and
@@ -2278,9 +2278,9 @@ module Make1<LocationSig Location, InputSig1<Location> Input1> {
        * type.
        *
        * When no call-context based post-processing is needed, simply implement this
-       * predicate as `result = inferCallArgumentTypeTopDown(_, _, _, n, path)`.
+       * predicate as `result = inferCallArgumentType(_, _, _, n, path)`.
        */
-      Type inferCallArgumentTypeTopDown(AstNode n, TypePath path);
+      Type inferCallArgumentType(AstNode n, TypePath path);
 
       /**
        * Holds if `n1` having certain type `t` at `path1` implies that `n2` has
@@ -2475,14 +2475,33 @@ module Make1<LocationSig Location, InputSig1<Location> Input1> {
       }
 
       pragma[nomagic]
-      private Type inferTypeFromStepRev(AstNode n, TypePath path) {
+      private predicate hasUnknownTypeAt(AstNode n, TypePath path) {
+        inferType(n, path) instanceof UnknownType
+      }
+
+      pragma[nomagic]
+      private predicate hasUnknownType(AstNode n) { hasUnknownTypeAt(n, _) }
+
+      pragma[nomagic]
+      private Type inferTypeTopDownCand(AstNode n, TypePath path) {
+        result = inferTypeTopDown(n, path)
+        or
+        result = inferCallArgumentType(n, path)
+        or
         exists(TypePath path1, AstNode n2, TypePath path2, TypePath suffix |
           result = inferType(n2, path2.appendInverse(suffix)) and
           path = path1.append(suffix) and
           step(n, path1, n2, path2)
         )
       }
 
+      pragma[nomagic]
+      private Type inferTypeTopDownCand(AstNode n, TypePath prefix, TypePath path) {
+        result = inferTypeTopDownCand(n, path) and
+        hasUnknownType(n) and
+        prefix = path.getAPrefix()
+      }
+
       private Type inferType0(AstNode n, TypePath path) {
         result = Input3::inferType(n, path)
         or
@@ -2497,13 +2516,13 @@ module Make1<LocationSig Location, InputSig1<Location> Input1> {
         or
         result = inferTypeFromStep(n, path)
         or
-        result = TopDownTyping<inferTypeFromStepRev/2>::inferType(n, path)
-        or
         result = inferCallReturnType(n, path)
         or
-        result = TopDownTyping<inferCallArgumentTypeTopDown/2>::inferType(n, path)
-        or
-        result = TopDownTyping<inferTypeTopDown/2>::inferType(n, path)
+        // top-down inference
+        exists(TypePath prefix |
+          result = inferTypeTopDownCand(n, prefix, path) and
+          hasUnknownTypeAt(n, prefix)
+        )
       }
 
       /**
@@ -2581,7 +2600,7 @@ module Make1<LocationSig Location, InputSig1<Location> Input1> {
         class Access extends CallFinal {
           bindingset[e]
           Type getInferredType(AccessEnvironment e, AccessPosition apos, TypePath path) {
-            result = inferCallTypeBottomUp(this, e, apos, path)
+            result = inferCallTypeAtPos(this, e, apos, path)
           }
         }
       }
@@ -2602,47 +2621,14 @@ module Make1<LocationSig Location, InputSig1<Location> Input1> {
         )
       }
 
-      Type inferCallArgumentTypeTopDown(
+      Type inferCallArgumentType(
         Call call, CallResolutionContext ctx, TypePosition pos, AstNode n, TypePath path
       ) {
         result = inferCallType(call, ctx, pos, n, path) and
         not pos.isReturn() and
         hasUnknownType(n)
       }
 
-      pragma[nomagic]
-      private predicate hasUnknownTypeAt(AstNode n, TypePath path) {
-        inferType(n, path) instanceof UnknownType
-      }
-
-      pragma[nomagic]
-      private predicate hasUnknownType(AstNode n) { hasUnknownTypeAt(n, _) }
-
-      private signature Type inferTypeTopDownSig(AstNode n, TypePath path);
-
-      /**
-       * Given a predicate `infer` for inferring the type of an AST node `n`
-       * top-down from a context, this module exposes the predicate `inferType`, which
-       * restricts type information to only flow top-down into `n` when `n` has an
-       * explicit unknown type.
-       */
-      private module TopDownTyping<inferTypeTopDownSig/2 infer> {
-        pragma[nomagic]
-        private Type inferTypeTopDown(AstNode n, TypePath prefix, TypePath path) {
-          result = infer(n, path) and
-          hasUnknownType(n) and
-          prefix = path.getAPrefix()
-        }
-
-        pragma[nomagic]
-        Type inferType(AstNode n, TypePath path) {
-          exists(TypePath prefix |
-            result = inferTypeTopDown(n, prefix, path) and
-            hasUnknownTypeAt(n, prefix)
-          )
-        }
-      }
-
       /**
        * Gets the inferred root type of `n`, if any.
        */