C#: Delete CFG for static assignables.

Author: aschackmull

csharp/ql/consistency-queries/DataFlowConsistency.ql

@@ -1,26 +1,11 @@
 import csharp
-private import semmle.code.csharp.controlflow.internal.ControlFlowGraphImpl as ControlFlowGraphImpl
 private import semmle.code.csharp.dataflow.internal.DataFlowImplSpecific
 private import semmle.code.csharp.dataflow.internal.TaintTrackingImplSpecific
 private import codeql.dataflow.internal.DataFlowImplConsistency
 
 private module Input implements InputSig<Location, CsharpDataFlow> {
   private import CsharpDataFlow
 
-  private predicate isStaticAssignable(Assignable a) { a.(Modifiable).isStatic() }
-
-  predicate uniqueEnclosingCallableExclude(Node node) {
-    // TODO: Remove once static initializers are folded into the
-    // static constructors
-    isStaticAssignable(ControlFlowGraphImpl::getNodeCfgScope(node.getControlFlowNode()))
-  }
-
-  predicate uniqueCallEnclosingCallableExclude(DataFlowCall call) {
-    // TODO: Remove once static initializers are folded into the
-    // static constructors
-    isStaticAssignable(ControlFlowGraphImpl::getNodeCfgScope(call.getControlFlowNode()))
-  }
-
   predicate uniqueNodeLocationExclude(Node n) {
     // Methods with multiple implementations
     n instanceof ParameterNode

csharp/ql/consistency-queries/VariableCaptureConsistency.ql

@@ -2,11 +2,9 @@ import csharp
 import semmle.code.csharp.dataflow.internal.DataFlowPrivate::VariableCapture::Flow::ConsistencyChecks
 private import semmle.code.csharp.dataflow.internal.DataFlowPrivate::VariableCapture::Flow::ConsistencyChecks as ConsistencyChecks
 private import semmle.code.csharp.controlflow.BasicBlocks
-private import semmle.code.csharp.controlflow.internal.ControlFlowGraphImpl
 
 query predicate uniqueEnclosingCallable(BasicBlock bb, string msg) {
-  ConsistencyChecks::uniqueEnclosingCallable(bb, msg) and
-  getNodeCfgScope(bb.getFirstNode()) instanceof Callable
+  ConsistencyChecks::uniqueEnclosingCallable(bb, msg)
 }
 
 query predicate consistencyOverview(string msg, int n) { none() }

csharp/ql/lib/semmle/code/csharp/controlflow/internal/ControlFlowGraphImpl.qll

@@ -66,23 +66,15 @@ private module Initializers {
 }
 
 /** An element that defines a new CFG scope. */
-class CfgScope extends Element, @top_level_exprorstmt_parent {
+class CfgScope extends Callable {
   CfgScope() {
     this.getFile().fromSource() and
     (
-      this =
-        any(Callable c |
-          c.(Constructor).hasInitializer()
-          or
-          Initializers::obinitInitializes(c, _)
-          or
-          c.hasBody()
-        )
+      this.(Constructor).hasInitializer()
       or
-      // For now, static initializer values have their own scope. Eventually, they
-      // should be treated like instance initializers.
-      this.(Assignable).(Modifiable).isStatic() and
-      expr_parent_top_level_adjusted2(_, _, this)
+      Initializers::obinitInitializes(this, _)
+      or
+      this.hasBody()
     )
   }
 }
@@ -189,24 +181,6 @@ CompilationExt getCompilation(File f) {
   result = TBuildless()
 }
 
-/**
- * The `expr_parent_top_level_adjusted()` relation restricted to exclude relations
- * between properties and their getters' expression bodies in properties such as
- * `int P => 0`.
- *
- * This is in order to only associate the expression body with one CFG scope, namely
- * the getter (and not the declaration itself).
- */
-private predicate expr_parent_top_level_adjusted2(
-  Expr child, int i, @top_level_exprorstmt_parent parent
-) {
-  expr_parent_top_level_adjusted(child, i, parent) and
-  not exists(Getter g |
-    g.getDeclaration() = parent and
-    i = 0
-  )
-}
-
 /** Holds if `first` is first executed when entering `scope`. */
 predicate scopeFirst(CfgScope scope, AstNode first) {
   scope =
@@ -220,9 +194,6 @@ predicate scopeFirst(CfgScope scope, AstNode first) {
     )
   or
   first(Initializers::initializedInstanceMemberOrder(scope, _, 0), first)
-  or
-  expr_parent_top_level_adjusted2(any(Expr e | first(e, first)), _, scope) and
-  not scope instanceof Callable
 }
 
 /** Holds if `scope` is exited when `last` finishes with completion `c`. */
@@ -244,9 +215,6 @@ predicate scopeLast(CfgScope scope, AstNode last, Completion c) {
     )
   or
   last(Initializers::lastInitializer(scope, _), last, c)
-  or
-  expr_parent_top_level_adjusted2(any(Expr e | last(e, last, c)), _, scope) and
-  not scope instanceof Callable
 }
 
 private class ObjectInitTree extends ControlFlowTree instanceof ObjectInitMethod {

csharp/ql/lib/semmle/code/csharp/dataflow/internal/rangeanalysis/ModulusAnalysisSpecific.qll

@@ -4,7 +4,6 @@ module Private {
   private import semmle.code.csharp.dataflow.internal.rangeanalysis.RangeUtils as RU
   private import SsaUtils as SU
   private import SsaReadPositionCommon
-  private import semmle.code.csharp.controlflow.internal.ControlFlowGraphImpl as CfgImpl
 
   class BasicBlock = CS::ControlFlow::BasicBlock;