Rust: Move CFG consistency logic into a library.

Author: geoffw0

rust/ql/consistency-queries/CfgConsistency.ql

@@ -1,37 +1 @@
-import rust
-import codeql.rust.controlflow.internal.ControlFlowGraphImpl::Consistency as Consistency
-import Consistency
-import codeql.rust.controlflow.ControlFlowGraph
-import codeql.rust.controlflow.internal.ControlFlowGraphImpl as CfgImpl
-import codeql.rust.controlflow.internal.Completion
-
-/**
- * All `Expr` nodes are `PostOrderTree`s
- */
-query predicate nonPostOrderExpr(Expr e, string cls) {
-  cls = e.getPrimaryQlClasses() and
-  not e instanceof LetExpr and
-  not e instanceof ParenExpr and
-  exists(AstNode last, Completion c |
-    CfgImpl::last(e, last, c) and
-    last != e and
-    c instanceof NormalCompletion
-  )
-}
-
-query predicate scopeNoFirst(CfgScope scope) {
-  Consistency::scopeNoFirst(scope) and
-  not scope = any(Function f | not exists(f.getBody())) and
-  not scope = any(ClosureExpr c | not exists(c.getBody()))
-}
-
-/** Holds if  `be` is the `else` branch of a `let` statement that results in a panic. */
-private predicate letElsePanic(BlockExpr be) {
-  be = any(LetStmt let).getLetElse().getBlockExpr() and
-  exists(Completion c | CfgImpl::last(be, _, c) | completionIsNormal(c))
-}
-
-query predicate deadEnd(CfgImpl::Node node) {
-  Consistency::deadEnd(node) and
-  not letElsePanic(node.getAstNode())
-}
+import codeql.rust.controlflow.internal.CfgConsistency

rust/ql/lib/codeql/rust/controlflow/internal/CfgConsistency.qll

@@ -0,0 +1,41 @@
+/**
+ * Provides classes for recognizing control flow graph inconsistencies.
+ */
+
+private import rust
+private import codeql.rust.controlflow.internal.ControlFlowGraphImpl::Consistency as Consistency
+import Consistency
+private import codeql.rust.controlflow.ControlFlowGraph
+private import codeql.rust.controlflow.internal.ControlFlowGraphImpl as CfgImpl
+private import codeql.rust.controlflow.internal.Completion
+
+/**
+ * All `Expr` nodes are `PostOrderTree`s
+ */
+query predicate nonPostOrderExpr(Expr e, string cls) {
+  cls = e.getPrimaryQlClasses() and
+  not e instanceof LetExpr and
+  not e instanceof ParenExpr and
+  exists(AstNode last, Completion c |
+    CfgImpl::last(e, last, c) and
+    last != e and
+    c instanceof NormalCompletion
+  )
+}
+
+query predicate scopeNoFirst(CfgScope scope) {
+  Consistency::scopeNoFirst(scope) and
+  not scope = any(Function f | not exists(f.getBody())) and
+  not scope = any(ClosureExpr c | not exists(c.getBody()))
+}
+
+/** Holds if  `be` is the `else` branch of a `let` statement that results in a panic. */
+private predicate letElsePanic(BlockExpr be) {
+  be = any(LetStmt let).getLetElse().getBlockExpr() and
+  exists(Completion c | CfgImpl::last(be, _, c) | completionIsNormal(c))
+}
+
+query predicate deadEnd(CfgImpl::Node node) {
+  Consistency::deadEnd(node) and
+  not letElsePanic(node.getAstNode())
+}