Merge pull request #19975 from hvitved/rust/ssa-phi-in-capture

Rust: Fix SSA inconsistencies

Author: hvitved

rust/ql/lib/codeql/rust/dataflow/internal/SsaImpl.qll

@@ -144,12 +144,6 @@ private predicate writesCapturedVariable(BasicBlock bb, Variable v) {
   getACapturedVariableAccess(bb, v) instanceof VariableWriteAccess
 }
 
-/** Holds if `bb` contains a captured read to variable `v`. */
-pragma[nomagic]
-private predicate readsCapturedVariable(BasicBlock bb, Variable v) {
-  variableReadCertain(_, _, getACapturedVariableAccess(bb, v), _)
-}
-
 /**
  * Holds if captured variable `v` is read directly inside `scope`,
  * or inside a (transitively) nested scope of `scope`.
@@ -229,7 +223,7 @@ private module Cached {
    */
   cached
   predicate capturedEntryWrite(EntryBasicBlock bb, int i, Variable v) {
-    readsCapturedVariable(bb.getASuccessor*(), v) and
+    exists(getACapturedVariableAccess(bb.getASuccessor*(), v)) and
     i = -1
   }
 

rust/ql/test/library-tests/variables/CONSISTENCY/PathResolutionConsistency.expected

@@ -1,3 +1,3 @@
 multipleCallTargets
-| main.rs:85:19:85:40 | ...::from(...) |
-| main.rs:102:19:102:40 | ...::from(...) |
+| main.rs:87:19:87:40 | ...::from(...) |
+| main.rs:106:19:106:40 | ...::from(...) |