feat(ast): Implement conditionals and loops support in Bicep AST

Author: GeekMasher

ql/lib/codeql/bicep/ast/Conditionals.qll

@@ -0,0 +1,27 @@
+/**
+ * Loop statements are not supported in `bicep` code.
+ */
+
+private import Expr
+private import Stmts
+private import internal.Conditionals
+
+
+ class Conditionals extends Stmts instanceof ConditionalsImpl {
+  /**
+   * Gets the condition expression of this conditional statement, if any.
+   *
+   * For if/elseif statements, this is the boolean expression in parentheses.
+   * For switch statements, this is the expression being switched on.
+   * For else clauses and default cases, this returns no result as they have no condition.
+   */
+  Expr getCondition() { result = ConditionalsImpl.super.getCondition() }
+
+  /**
+   * Gets the branch (statement sequence) executed when this conditional is satisfied.
+   *
+   * This represents the code that runs when the condition is true or when
+   * this branch is selected in a switch/match statement.
+   */
+  StmtSequence getBranch() { result = ConditionalsImpl.super.getBranch() }
+}

ql/lib/codeql/bicep/ast/Loops.qll

@@ -1,4 +1,72 @@
+private import AstNodes
+private import Expr
+private import Idents
+private import Stmts
+private import internal.Loops
+private import internal.ForStatement
+
+class Loops extends Stmts instanceof LoopsImpl {
+  /**
+   * Gets the condition expression of the loop.
+   *
+   * This is the expression that determines whether the loop continues executing.
+   * For while and for loops, this is the explicit condition expression.
+   * For do-while loops, this is the condition evaluated after each iteration.
+   * For foreach loops, this represents an implicit condition checking if there are more elements.
+   */
+  abstract Expr getCondition();
+
+  /**
+   * Gets the body of the loop.
+   *
+   * The body contains the statements that are executed in each iteration of the loop.
+   * In the CFG, control typically flows back from the end of the body to the loop condition
+   * or to the update expression (in for loops).
+   */
+  abstract Stmts getBody();
+
+  /**
+   * Gets the initializer of the loop, if any.
+   *
+   * For for loops, this includes the variables initialized before the loop starts.
+   * For foreach loops, this includes the key and value variables declared for iteration.
+   * Other loop types may not have initializers.
+   */
+  abstract Idents getInitializer();
+}
 
 /**
- * Loop statements are not supported in `bicep` code.
+ * A for statement in Bicep.
+ *
+ * In Bicep, for loops are used to iterate over arrays, integer ranges, or object properties.
+ * They can be used to create multiple instances of resources, modules, variables, or properties.
+ *
+ * Example:
+ * ```bicep
+ * // Creating multiple storage accounts using a for loop with range
+ * resource storageAcct 'Microsoft.Storage/storageAccounts@2023-05-01' = [for i in range(0, storageCount): {
+ *   name: '${i}storage${uniqueString(resourceGroup().id)}'
+ *   location: location
+ *   sku: {
+ *     name: 'Standard_LRS'
+ *   }
+ *   kind: 'Storage'
+ * }]
+ * ```
  */
+class ForStatement extends Loops instanceof ForStatementImpl {
+  /** Gets the condition expression of this for loop. */
+  override Expr getCondition() {
+    result = ForStatementImpl.super.getCondition()
+  }
+
+  /** Gets the body of this for loop. */
+  override Stmts getBody() {
+    result = ForStatementImpl.super.getBody()
+  }
+
+  /** Gets the initializer of this for loop. */
+  override Idents getInitializer() {
+    result = ForStatementImpl.super.getInitializer()
+  }
+}

ql/lib/codeql/bicep/ast/internal/Conditionals.qll

@@ -6,12 +6,17 @@ private import codeql.bicep.ast.AstNodes
 private import AstNodes
 private import TreeSitter
 private import Expr
+private import Stmts
+// Re-exports
+import ForStatement
 
 /**
  * Conditional statements.
  */
-class ConditionalExprImpl extends ExprImpl, TConditionalExpr {
+class ConditionalsImpl extends StmtsImpl, TConditionals {
   override string getAPrimaryQlClass() { result = "Conditional" }
 
   abstract ExprImpl getCondition();
+
+  abstract StmtSequenceImpl getBranch();
 }

ql/lib/codeql/bicep/ast/internal/ForStatement.qll

@@ -1,26 +1,41 @@
 /**
  *  Internal implementation for ForStatement
- *
- *  WARNING: this file is generated, do not edit manually
  */
+
 private import AstNodes
 private import TreeSitter
 private import codeql.bicep.ast.AstNodes
 private import Stmts
-
+private import Loops
+private import Expr
+private import Idents
 
 /**
  *  A ForStatement AST Node.
  */
-class ForStatementImpl extends TForStatement, StmtsImpl {
+class ForStatementImpl extends TForStatement, LoopsImpl {
   private BICEP::ForStatement ast;
 
   override string getAPrimaryQlClass() { result = "ForStatement" }
 
   ForStatementImpl() { this = TForStatement(ast) }
 
   override string toString() { result = ast.toString() }
-
-
-
-}
+  
+  override ExprImpl getCondition() {
+    // In Bicep, for loops don't have explicit conditions like other languages,
+    // but the loop enumeration object can be considered the condition
+    // We use child index 1 which should be the loop condition/enumeration
+    toTreeSitter(result) = ast.getChild(1)
+  }
+
+  override ExprImpl getBody() {
+    // The body is the part to execute for each iteration
+    toTreeSitter(result) = ast.getBody()
+  }
+
+  override IdentsImpl getInitializer() {
+    // The initializer is the loop variable
+    toTreeSitter(result) = ast.getInitializer()
+  }
+}

ql/lib/codeql/bicep/ast/internal/Loops.qll

@@ -1,4 +1,23 @@
-
 /**
- * Loop statements are not supported in `bicep` code.
- */
+ * Loop statements in Bicep code.
+ * 
+ * Bicep supports for loops for iterating over collections, ranges, or object properties.
+ * These loops are used to create multiple instances of resources, variables, or other elements.
+ */
+
+private import AstNodes
+private import TreeSitter
+private import codeql.bicep.ast.AstNodes
+private import Idents
+private import Stmts
+private import Expr
+
+abstract class LoopsImpl extends AstNode, TLoops {
+  override string getAPrimaryQlClass() { result = "Loops" }
+
+  abstract ExprImpl getCondition();
+
+  abstract ExprImpl getBody();
+
+  abstract IdentsImpl getInitializer();
+}