feat(cfg): Enhance control flow graph with additional AST node classes and tree structures for Bicep

Author: GeekMasher

ql/lib/codeql/bicep/controlflow/CfgNodes.qll

@@ -1,6 +1,9 @@
 /** Provides classes representing nodes in a control flow graph. */
 
 private import bicep
+private import codeql.bicep.ast.Calls
+private import codeql.bicep.ast.Literals
+private import codeql.bicep.ast.Resources
 private import BasicBlocks
 private import ControlFlowGraph
 import internal.ControlFlowGraphImpl
@@ -29,15 +32,280 @@ class StmtsCfgNode extends AstCfgNode {
   Stmts getStmt() { result = s }
 }
 
+/** A control-flow node that wraps an AST literal. */
+class LiteralsCfgNode extends AstCfgNode {
+  string getAPrimaryQlClass() { result = "LiteralsCfgNode" }
+
+  Literals l;
+
+  LiteralsCfgNode() { l = this.getAstNode() }
+
+  /** Gets the underlying literal. */
+  Literals getLiteral() { result = l }
+}
+
 /** Provides classes for control-flow nodes that wrap AST expressions. */
-module ExprNodes { 
+module ExprNodes {
+  /** A mapping from a child of an expression to an expression. */
+  abstract class ExprChildMapping extends Expr {
+    /** Holds if `n` is a relevant child of this expression. */
+    abstract predicate relevantChild(AstNode n);
+  }
+
+  /** A mapping from a child of a literal to a literal. */
+  abstract class LiteralChildMapping extends AstNode {
+    /** Holds if `n` is a relevant child of this literal. */
+    abstract predicate relevantChild(AstNode n);
+  }
+
+  /** A control-flow node that wraps an Array AST node. */
+  class ArrayCfgNode extends LiteralsCfgNode {
+    override string getAPrimaryQlClass() { result = "ArrayCfgNode" }
+
+    Array e;
+
+    ArrayCfgNode() { l = this.getLiteral() }
+
+    /** Gets the underlying array literal. */
+    Array getArray() { result = l }
+  }
+
+  /** A control-flow node that wraps a Boolean AST node. */
+  class BooleanCfgNode extends LiteralsCfgNode {
+    override string getAPrimaryQlClass() { result = "BooleanCfgNode" }
+
+    Boolean e;
+
+    BooleanCfgNode() { l = this.getLiteral() }
+
+    /** Gets the underlying boolean literal. */
+    Boolean getBoolean() { result = l }
+  }
+
+  /** A control-flow node that wraps a NullLiteral AST node. */
+  class NullLiteralCfgNode extends LiteralsCfgNode {
+    override string getAPrimaryQlClass() { result = "NullLiteralCfgNode" }
+
+    NullLiteral e;
+
+    NullLiteralCfgNode() { l = this.getLiteral() }
+
+    /** Gets the underlying null literal. */
+    NullLiteral getNullLiteral() { result = l }
+  }
+
+  /** A control-flow node that wraps a Number AST node. */
+  class NumberCfgNode extends LiteralsCfgNode {
+    override string getAPrimaryQlClass() { result = "NumberCfgNode" }
+
+    Number e;
+
+    NumberCfgNode() { l = this.getLiteral() }
+
+    /** Gets the underlying number literal. */
+    Number getNumber() { result = l }
+  }
+
+  /** A control-flow node that wraps a StringLiteral AST node. */
+  class StringLiteralCfgNode extends LiteralsCfgNode {
+    override string getAPrimaryQlClass() { result = "StringLiteralCfgNode" }
+
+    StringLiteral e;
+
+    StringLiteralCfgNode() { l = this.getLiteral() }
+
+    /** Gets the underlying string literal. */
+    StringLiteral getStringLiteral() { result = l }
+  }
+
+  /** A control-flow node that wraps a StringContentLiteral AST node. */
+  class StringContentLiteralCfgNode extends LiteralsCfgNode {
+    override string getAPrimaryQlClass() { result = "StringContentLiteralCfgNode" }
+
+    StringContentLiteral e;
+
+    StringContentLiteralCfgNode() { l = this.getLiteral() }
+
+    /** Gets the underlying string content literal. */
+    StringContentLiteral getStringContentLiteral() { result = l }
+  }
+
+  /** A control-flow node that wraps a CallExpression AST node. */
   class CallCfgNode extends ExprCfgNode {
     override string getAPrimaryQlClass() { result = "CallCfgNode" }
 
     override CallExpression e;
 
     override CallExpression getExpr() { result = super.getExpr() }
   }
+
+  /** A mapping from a child of an Arguments expression to the expression. */
+  abstract class ArgumentsChildMapping extends ExprChildMapping, Arguments {
+    override predicate relevantChild(AstNode n) { n = this.getArgument(_) }
+  }
+
+  /** A control-flow node that wraps an Arguments AST node. */
+  class ArgumentsCfgNode extends ExprCfgNode {
+    override string getAPrimaryQlClass() { result = "ArgumentsCfgNode" }
+
+    override Arguments e;
+
+    override Arguments getExpr() { result = super.getExpr() }
+  }
+
+  /** A mapping from a child of an AssignmentExpression to the expression. */
+  abstract class AssignmentExpressionChildMapping extends ExprChildMapping, AssignmentExpression {
+    override predicate relevantChild(AstNode n) { n = this.getLeft() or n = this.getRight() }
+  }
+
+  /** A control-flow node that wraps an AssignmentExpression AST node. */
+  class AssignmentExpressionCfgNode extends ExprCfgNode {
+    override string getAPrimaryQlClass() { result = "AssignmentExpressionCfgNode" }
+
+    override AssignmentExpression e;
+
+    override AssignmentExpression getExpr() { result = super.getExpr() }
+  }
+
+  /** A mapping from a child of a BinaryExpression to the expression. */
+  abstract class BinaryExpressionChildMapping extends ExprChildMapping, BinaryExpression {
+    override predicate relevantChild(AstNode n) { n = this.getLeft() or n = this.getRight() }
+  }
+
+  /** A control-flow node that wraps a BinaryExpression AST node. */
+  class BinaryExpressionCfgNode extends ExprCfgNode {
+    override string getAPrimaryQlClass() { result = "BinaryExpressionCfgNode" }
+
+    override BinaryExpression e;
+
+    override BinaryExpression getExpr() { result = super.getExpr() }
+
+    /** Gets the left operand CFG node */
+    final ExprCfgNode getLeftOperand() {
+      result = this.getAPredecessor().(ExprCfgNode) and
+      result.getExpr() = this.getExpr().getLeft()
+    }
+
+    /** Gets the right operand CFG node */
+    final ExprCfgNode getRightOperand() {
+      result = this.getAPredecessor().(ExprCfgNode) and
+      result.getExpr() = this.getExpr().getRight()
+    }
+  }
+
+  /** A mapping from a child of an Interpolation to the expression. */
+  abstract class InterpolationChildMapping extends ExprChildMapping, Interpolation {
+    override predicate relevantChild(AstNode n) { n = this.getExpression() }
+  }
+
+  /** A control-flow node that wraps an Interpolation AST node. */
+  class InterpolationCfgNode extends ExprCfgNode {
+    override string getAPrimaryQlClass() { result = "InterpolationCfgNode" }
+
+    override Interpolation e;
+
+    override Interpolation getExpr() { result = super.getExpr() }
+  }
+
+  /** A mapping from a child of a LambdaExpression to the expression. */
+  abstract class LambdaExpressionChildMapping extends ExprChildMapping, LambdaExpression {
+    override predicate relevantChild(AstNode n) { n = this.getAChild() }
+  }
+
+  /** A control-flow node that wraps a LambdaExpression AST node. */
+  class LambdaExpressionCfgNode extends ExprCfgNode {
+    override string getAPrimaryQlClass() { result = "LambdaExpressionCfgNode" }
+
+    override LambdaExpression e;
+
+    override LambdaExpression getExpr() { result = super.getExpr() }
+  }
+
+  /** A mapping from a child of a MemberExpression to the expression. */
+  abstract class MemberExpressionChildMapping extends ExprChildMapping, MemberExpression {
+    override predicate relevantChild(AstNode n) { n = this.getNamespace() or n = this.getName() }
+  }
+
+  /** A control-flow node that wraps a MemberExpression AST node. */
+  class MemberExpressionCfgNode extends ExprCfgNode {
+    override string getAPrimaryQlClass() { result = "MemberExpressionCfgNode" }
+
+    override MemberExpression e;
+
+    override MemberExpression getExpr() { result = super.getExpr() }
+  }
+
+  /** A mapping from a child of a NullableType to the expression. */
+  abstract class NullableTypeChildMapping extends ExprChildMapping, NullableType {
+    override predicate relevantChild(AstNode n) { n = this.getAChild() }
+  }
+
+  /** A control-flow node that wraps a NullableType AST node. */
+  class NullableTypeCfgNode extends ExprCfgNode {
+    override string getAPrimaryQlClass() { result = "NullableTypeCfgNode" }
+
+    override NullableType e;
+
+    override NullableType getExpr() { result = super.getExpr() }
+  }
+
+  /** A mapping from a child of a ParenthesizedExpression to the expression. */
+  abstract class ParenthesizedExpressionChildMapping extends ExprChildMapping,
+    ParenthesizedExpression
+  {
+    override predicate relevantChild(AstNode n) { n = this.getExpression(_) }
+  }
+
+  /** A control-flow node that wraps a ParenthesizedExpression AST node. */
+  class ParenthesizedExpressionCfgNode extends ExprCfgNode {
+    override string getAPrimaryQlClass() { result = "ParenthesizedExpressionCfgNode" }
+
+    override ParenthesizedExpression e;
+
+    override ParenthesizedExpression getExpr() { result = super.getExpr() }
+  }
+
+  /** A mapping from a child of a ResourceExpression to the expression. */
+  abstract class ResourceExpressionChildMapping extends ExprChildMapping, ResourceExpression {
+    override predicate relevantChild(AstNode n) { n = this.getAChild() }
+  }
+
+  /** A control-flow node that wraps a ResourceExpression AST node. */
+  class ResourceExpressionCfgNode extends ExprCfgNode {
+    override string getAPrimaryQlClass() { result = "ResourceExpressionCfgNode" }
+
+    override ResourceExpression e;
+
+    override ResourceExpression getExpr() { result = super.getExpr() }
+  }
+
+  /** A mapping from a child of a TernaryExpression to the expression. */
+  abstract class TernaryExpressionChildMapping extends ExprChildMapping, TernaryExpression {
+    override predicate relevantChild(AstNode n) { n = this.getAChild() }
+  }
+
+  /** A control-flow node that wraps a TernaryExpression AST node. */
+  class TernaryExpressionCfgNode extends ExprCfgNode {
+    override string getAPrimaryQlClass() { result = "TernaryExpressionCfgNode" }
+
+    override TernaryExpression e;
+
+    override TernaryExpression getExpr() { result = super.getExpr() }
+  }
+
+  /** A mapping from a child of a UnaryExpression to the expression. */
+  abstract class UnaryExpressionChildMapping extends ExprChildMapping, UnaryExpression {
+    override predicate relevantChild(AstNode n) { n = this.getAChild() }
+  }
+
+  /** A control-flow node that wraps a UnaryExpression AST node. */
+  class UnaryExpressionCfgNode extends ExprCfgNode {
+    override string getAPrimaryQlClass() { result = "UnaryExpressionCfgNode" }
+
+    override UnaryExpression e;
+
+    override UnaryExpression getExpr() { result = super.getExpr() }
+  }
 }
 
 module StmtNodes {
@@ -49,4 +317,4 @@ module StmtNodes {
 
     override UserDefinedFunction getStmt() { result = super.getStmt() }
   }
-}
+}