Merge pull request #15736 from michaelnebel/csharp/disconnectfromdotnet

C#: Deprecate dotnet and CIL in QL.

Author: michaelnebel

csharp/ql/consistency-queries/DataFlowConsistency.ql

@@ -1,5 +1,4 @@
 import csharp
-import cil
 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
@@ -31,11 +30,6 @@ private module Input implements InputSig<CsharpDataFlow> {
     n instanceof FlowInsensitiveFieldNode
   }
 
-  predicate missingLocationExclude(Node n) {
-    // Some CIL methods are missing locations
-    n.asParameter() instanceof CIL::Parameter
-  }
-
   predicate postWithInFlowExclude(Node n) {
     n instanceof FlowSummaryNode
     or
@@ -48,8 +42,6 @@ private module Input implements InputSig<CsharpDataFlow> {
     not exists(LocalFlow::getAPostUpdateNodeForArg(n.getControlFlowNode()))
     or
     n instanceof ParamsArgumentNode
-    or
-    n.asExpr() instanceof CIL::Expr
   }
 
   predicate postHasUniquePreExclude(PostUpdateNode n) {

csharp/ql/lib/change-notes/2024-03-04-deprecate-dotnet-and-cil.md

@@ -0,0 +1,4 @@
+---
+category: breaking
+---
+* The QL library C# classes no longer extend their corresponding `DotNet` classes. Furthermore, CIL related data flow functionality has been deleted and all `DotNet` and `CIL` related classes have been deprecated. This effectively means that it no longer has any effect to enable CIL extraction.

csharp/ql/lib/dotnet.qll

@@ -2,4 +2,4 @@
  * The default QL library for modeling .NET definitions for both C# and CIL code.
  */
 
-import semmle.code.dotnet.DotNet as DotNet
+deprecated import semmle.code.dotnet.DotNet as DotNet

csharp/ql/lib/semmle/code/cil/Access.qll

@@ -7,7 +7,7 @@
 private import CIL
 
 /** An instruction that accesses a variable. */
-class Access extends Instruction, @cil_access {
+deprecated class Access extends Instruction, @cil_access {
   /** Gets the declaration referenced by this instruction. */
   Variable getTarget() { cil_access(this, result) }
 }
@@ -16,59 +16,59 @@ class Access extends Instruction, @cil_access {
  * An instruction that accesses a variable.
  * This class is provided for consistency with the C# data model.
  */
-class VariableAccess extends Access, @cil_access { }
+deprecated class VariableAccess extends Access, @cil_access { }
 
 /** An instruction that reads a variable. */
-class ReadAccess extends VariableAccess, Expr, @cil_read_access {
+deprecated class ReadAccess extends VariableAccess, Expr, @cil_read_access {
   override Type getType() { result = this.getTarget().getType() }
 }
 
 /** An instruction yielding an address. */
-class ReadRef extends Expr, @cil_read_ref { }
+deprecated class ReadRef extends Expr, @cil_read_ref { }
 
 /** An instruction that reads the address of a variable. */
-class ReadRefAccess extends ReadAccess, ReadRef { }
+deprecated class ReadRefAccess extends ReadAccess, ReadRef { }
 
 /** An instruction that writes a variable. */
-class WriteAccess extends VariableAccess, @cil_write_access {
+deprecated class WriteAccess extends VariableAccess, @cil_write_access {
   /** Gets the expression whose value is used in this variable write. */
   Expr getExpr() { none() }
 }
 
 /** An instruction that accesses a parameter. */
-class ParameterAccess extends StackVariableAccess, @cil_arg_access {
+deprecated class ParameterAccess extends StackVariableAccess, @cil_arg_access {
   override MethodParameter getTarget() { result = StackVariableAccess.super.getTarget() }
 }
 
 /** An instruction that reads a parameter. */
-class ParameterReadAccess extends ParameterAccess, ReadAccess {
+deprecated class ParameterReadAccess extends ParameterAccess, ReadAccess {
   override int getPopCount() { result = 0 }
 }
 
 /** An instruction that writes to a parameter. */
-class ParameterWriteAccess extends ParameterAccess, WriteAccess {
+deprecated class ParameterWriteAccess extends ParameterAccess, WriteAccess {
   override int getPopCount() { result = 1 }
 
   override Expr getExpr() { result = this.getOperand(0) }
 }
 
 /** An access to the `this` parameter. */
-class ThisAccess extends ParameterReadAccess {
+deprecated class ThisAccess extends ParameterReadAccess {
   ThisAccess() { this.getTarget() instanceof ThisParameter }
 }
 
 /** An instruction that accesses a stack variable. */
-class StackVariableAccess extends VariableAccess, @cil_stack_access {
+deprecated class StackVariableAccess extends VariableAccess, @cil_stack_access {
   override StackVariable getTarget() { result = VariableAccess.super.getTarget() }
 }
 
 /** An instruction that accesses a local variable. */
-class LocalVariableAccess extends StackVariableAccess, @cil_local_access {
+deprecated class LocalVariableAccess extends StackVariableAccess, @cil_local_access {
   override LocalVariable getTarget() { result = StackVariableAccess.super.getTarget() }
 }
 
 /** An instruction that writes to a local variable. */
-class LocalVariableWriteAccess extends LocalVariableAccess, WriteAccess {
+deprecated class LocalVariableWriteAccess extends LocalVariableAccess, WriteAccess {
   override int getPopCount() { result = 1 }
 
   override Expr getExpr() { result = this.getOperand(0) }
@@ -77,12 +77,12 @@ class LocalVariableWriteAccess extends LocalVariableAccess, WriteAccess {
 }
 
 /** An instruction that reads a local variable. */
-class LocalVariableReadAccess extends LocalVariableAccess, ReadAccess {
+deprecated class LocalVariableReadAccess extends LocalVariableAccess, ReadAccess {
   override int getPopCount() { result = 0 }
 }
 
 /** An instruction that accesses a field. */
-class FieldAccess extends VariableAccess, @cil_field_access {
+deprecated class FieldAccess extends VariableAccess, @cil_field_access {
   override Field getTarget() { result = VariableAccess.super.getTarget() }
 
   override string getExtra() { result = this.getTarget().getName() }
@@ -92,7 +92,7 @@ class FieldAccess extends VariableAccess, @cil_field_access {
 }
 
 /** An instruction that reads a field. */
-abstract class FieldReadAccess extends FieldAccess, ReadAccess { }
+abstract deprecated class FieldReadAccess extends FieldAccess, ReadAccess { }
 
 /** An instruction that writes a field. */
-abstract class FieldWriteAccess extends FieldAccess, WriteAccess { }
+abstract deprecated class FieldWriteAccess extends FieldAccess, WriteAccess { }

csharp/ql/lib/semmle/code/cil/Attribute.qll

@@ -4,7 +4,7 @@ private import CIL
 private import semmle.code.csharp.Location as CS
 
 /** An attribute to a declaration, such as a method, field, type or parameter. */
-class Attribute extends Element, @cil_attribute {
+deprecated class Attribute extends Element, @cil_attribute {
   /** Gets the declaration this attribute is attached to. */
   Declaration getDeclaration() { cil_attribute(this, result, _) }
 
@@ -29,7 +29,7 @@ class Attribute extends Element, @cil_attribute {
 }
 
 /** A generic attribute to a declaration. */
-class GenericAttribute extends Attribute {
+deprecated class GenericAttribute extends Attribute {
   private ConstructedType type;
 
   GenericAttribute() { type = this.getType() }

csharp/ql/lib/semmle/code/cil/BasicBlock.qll

@@ -8,7 +8,7 @@ private import CIL
  * A basic block, that is, a maximal straight-line sequence of control flow nodes
  * without branches or joins.
  */
-class BasicBlock extends Cached::TBasicBlockStart {
+deprecated class BasicBlock extends Cached::TBasicBlockStart {
   /** Gets an immediate successor of this basic block, if any. */
   BasicBlock getASuccessor() { result.getFirstNode() = this.getLastNode().getASuccessor() }
 
@@ -249,7 +249,7 @@ class BasicBlock extends Cached::TBasicBlockStart {
  * Internal implementation details.
  */
 cached
-private module Cached {
+deprecated private module Cached {
   /** Internal representation of basic blocks. */
   cached
   newtype TBasicBlock = TBasicBlockStart(ControlFlowNode cfn) { startsBB(cfn) }
@@ -287,49 +287,54 @@ private module Cached {
  * Holds if the first node of basic block `succ` is a control flow
  * successor of the last node of basic block `pred`.
  */
-private predicate succBB(BasicBlock pred, BasicBlock succ) { succ = pred.getASuccessor() }
+deprecated private predicate succBB(BasicBlock pred, BasicBlock succ) {
+  succ = pred.getASuccessor()
+}
 
 /** Holds if `dom` is an immediate dominator of `bb`. */
-predicate bbIDominates(BasicBlock dom, BasicBlock bb) = idominance(entryBB/1, succBB/2)(_, dom, bb)
+deprecated predicate bbIDominates(BasicBlock dom, BasicBlock bb) =
+  idominance(entryBB/1, succBB/2)(_, dom, bb)
 
 /** Holds if `pred` is a basic block predecessor of `succ`. */
-private predicate predBB(BasicBlock succ, BasicBlock pred) { succBB(pred, succ) }
+deprecated private predicate predBB(BasicBlock succ, BasicBlock pred) { succBB(pred, succ) }
 
 /** Holds if `dom` is an immediate post-dominator of `bb`. */
-predicate bbIPostDominates(BasicBlock dom, BasicBlock bb) =
+deprecated predicate bbIPostDominates(BasicBlock dom, BasicBlock bb) =
   idominance(exitBB/1, predBB/2)(_, dom, bb)
 
 /**
  * An entry basic block, that is, a basic block whose first node is
  * the entry node of a callable.
  */
-class EntryBasicBlock extends BasicBlock {
+deprecated class EntryBasicBlock extends BasicBlock {
   EntryBasicBlock() { entryBB(this) }
 }
 
 /** Holds if `bb` is an entry basic block. */
-private predicate entryBB(BasicBlock bb) { bb.getFirstNode() instanceof MethodImplementation }
+deprecated private predicate entryBB(BasicBlock bb) {
+  bb.getFirstNode() instanceof MethodImplementation
+}
 
 /**
  * An exit basic block, that is, a basic block whose last node is
  * an exit node.
  */
-class ExitBasicBlock extends BasicBlock {
+deprecated class ExitBasicBlock extends BasicBlock {
   ExitBasicBlock() { exitBB(this) }
 }
 
 /** Holds if `bb` is an exit basic block. */
-private predicate exitBB(BasicBlock bb) { not exists(bb.getLastNode().getASuccessor()) }
+deprecated private predicate exitBB(BasicBlock bb) { not exists(bb.getLastNode().getASuccessor()) }
 
 /**
  * A basic block with more than one predecessor.
  */
-class JoinBlock extends BasicBlock {
+deprecated class JoinBlock extends BasicBlock {
   JoinBlock() { this.getFirstNode().isJoin() }
 }
 
 /** A basic block that terminates in a condition, splitting the subsequent control flow. */
-class ConditionBlock extends BasicBlock {
+deprecated class ConditionBlock extends BasicBlock {
   ConditionBlock() {
     exists(BasicBlock succ |
       succ = this.getATrueSuccessor()

csharp/ql/lib/semmle/code/cil/CallableReturns.qll

@@ -8,22 +8,26 @@ cached
 private module Cached {
   /** Holds if method `m` always returns null. */
   cached
-  predicate alwaysNullMethod(Method m) { forex(Expr e | m.canReturn(e) | alwaysNullExpr(e)) }
+  deprecated predicate alwaysNullMethod(Method m) {
+    forex(Expr e | m.canReturn(e) | alwaysNullExpr(e))
+  }
 
   /** Holds if method `m` always returns non-null. */
   cached
-  predicate alwaysNotNullMethod(Method m) { forex(Expr e | m.canReturn(e) | alwaysNotNullExpr(e)) }
+  deprecated predicate alwaysNotNullMethod(Method m) {
+    forex(Expr e | m.canReturn(e) | alwaysNotNullExpr(e))
+  }
 
   /** Holds if method `m` always throws an exception. */
   cached
-  predicate alwaysThrowsMethod(Method m) {
+  deprecated predicate alwaysThrowsMethod(Method m) {
     m.hasBody() and
     not exists(m.getImplementation().getAnInstruction().(Return))
   }
 
   /** Holds if method `m` always throws an exception of type `t`. */
   cached
-  predicate alwaysThrowsException(Method m, Type t) {
+  deprecated predicate alwaysThrowsException(Method m, Type t) {
     alwaysThrowsMethod(m) and
     forex(Throw ex | ex = m.getImplementation().getAnInstruction() | t = ex.getExceptionType())
   }
@@ -32,12 +36,12 @@ private module Cached {
 import Cached
 
 pragma[noinline]
-private predicate alwaysNullVariableUpdate(VariableUpdate vu) {
+deprecated private predicate alwaysNullVariableUpdate(VariableUpdate vu) {
   forex(Expr src | src = vu.getSource() | alwaysNullExpr(src))
 }
 
 /** Holds if expression `expr` always evaluates to `null`. */
-private predicate alwaysNullExpr(Expr expr) {
+deprecated private predicate alwaysNullExpr(Expr expr) {
   expr instanceof NullLiteral
   or
   alwaysNullMethod(expr.(StaticCall).getTarget())
@@ -50,12 +54,12 @@ private predicate alwaysNullExpr(Expr expr) {
 }
 
 pragma[noinline]
-private predicate alwaysNotNullVariableUpdate(VariableUpdate vu) {
+deprecated private predicate alwaysNotNullVariableUpdate(VariableUpdate vu) {
   forex(Expr src | src = vu.getSource() | alwaysNotNullExpr(src))
 }
 
 /** Holds if expression `expr` always evaluates to non-null. */
-private predicate alwaysNotNullExpr(Expr expr) {
+deprecated private predicate alwaysNotNullExpr(Expr expr) {
   expr instanceof Opcodes::NewObj
   or
   expr instanceof Literal and not expr instanceof NullLiteral