/**

* Provides classes for working with AST nodes.

*/

overlay[local]

module;

import go

/**

* An AST node.

*/

class AstNode extends @node, Locatable {

/**

* Gets the `i`th child node of this node.

*

* Note that the precise indices of child nodes are considered an implementation detail

* and are subject to change without notice.

*/

AstNode getChild(int i) {

result = this.(ExprParent).getChildExpr(i) or

result = this.(GoModExprParent).getChildGoModExpr(i) or

result = this.(StmtParent).getChildStmt(i) or

result = this.(DeclParent).getDecl(i) or

result = this.(GenDecl).getSpec(i) or

result = this.(FieldParent).getField(i) or

result = this.(File).getCommentGroup(i) or

result = this.(CommentGroup).getComment(i)

}

/**

* Gets a child node of this node.

*/

AstNode getAChild() { result = this.getChild(_) }

/**

* Gets the number of child nodes of this node.

*/

int getNumChild() { result = count(this.getAChild()) }

/**

* Gets a child with the given index and of the given kind, if one exists.

* Note that a given parent can have multiple children with the same index but differing kind.

*/

private AstNode getChildOfKind(string kind, int i) {

kind = "expr" and result = this.(ExprParent).getChildExpr(i)

or

kind = "gomodexpr" and result = this.(GoModExprParent).getChildGoModExpr(i)

or

kind = "stmt" and result = this.(StmtParent).getChildStmt(i)

or

kind = "decl" and result = this.(DeclParent).getDecl(i)

or

kind = "spec" and result = this.(GenDecl).getSpec(i)

or

kind = "field" and result = this.(FieldParent).getField(i)

or

kind = "commentgroup" and result = this.(File).getCommentGroup(i)

or

kind = "comment" and result = this.(CommentGroup).getComment(i)

or

kind = "typeparamdecl" and result = this.(TypeParamDeclParent).getTypeParameterDecl(i)

}

/**

* Get an AstNode child, ordered by child kind and then by index.

*/

AstNode getUniquelyNumberedChild(int index) {

result =

rank[index + 1](AstNode child, string kind, int i |

child = this.getChildOfKind(kind, i)

|

child order by kind, i

)

}

/** Gets the parent node of this AST node, if any. */

AstNode getParent() { this = result.getAChild() }

/** Gets the parent node of this AST node, but without crossing function boundaries. */

private AstNode parentInSameFunction() {

result = this.getParent() and

not this instanceof FuncDef

}

/** Gets the innermost function definition to which this AST node belongs, if any. */

pragma[nomagic]

FuncDef getEnclosingFunction() { result = this.getParent().parentInSameFunction*() }

/** Gets the innermost block statement to which this AST node belongs, if any. */

BlockStmt getEnclosingBlock() {

exists(AstNode p | p = this.getParent() |

result = p

or

not p instanceof BlockStmt and

result = p.getEnclosingBlock()

)

}

/**

* Gets a comma-separated list of the names of the primary CodeQL classes to which this element belongs.

*/

final string getPrimaryQlClasses() { result = concat(this.getAPrimaryQlClass(), ",") }

/**

* Gets the name of a primary CodeQL class to which this node belongs.

*

* For most nodes, this is simply the most precise syntactic category to which they belong;

* for example, `AddExpr` is a primary class, but `BinaryExpr` is not.

*

* For identifiers and selector expressions, the class describing what kind of entity they refer

* to (for example `FunctionName` or `TypeName`) is also considered primary. For such nodes,

* this predicate has multiple values.

*/

string getAPrimaryQlClass() { result = "???" }

override string toString() { result = "AST node" }

}

/**

* An AST node whose children include expressions.

*/

class ExprParent extends @exprparent, AstNode {

/**

* Gets the `i`th child expression of this node.

*

* Note that the precise indices of child expressions are considered an implementation detail

* and are subject to change without notice.

*/

Expr getChildExpr(int i) { exprs(result, _, this, i) }

/**

* Gets an expression that is a child node of this node in the AST.

*/

Expr getAChildExpr() { result = this.getChildExpr(_) }

/**

* Gets the number of child expressions of this node.

*/

int getNumChildExpr() { result = count(this.getAChildExpr()) }

}

/**

* An AST node whose children include go.mod expressions.

*/

class GoModExprParent extends @modexprparent, AstNode {

/**

* Gets the `i`th child expression of this node.

*

* Note that the precise indices of child expressions are considered an implementation detail

* and are subject to change without notice.

*/

GoModExpr getChildGoModExpr(int i) { modexprs(result, _, this, i) }

/**

* Gets an expression that is a child node of this node in the AST.

*/

GoModExpr getAChildGoModExpr() { result = this.getChildGoModExpr(_) }

/**

* Gets the number of child expressions of this node.

*/

int getNumChildGoModExpr() { result = count(this.getAChildGoModExpr()) }

}

/**

* An AST node whose children include statements.

*/

class StmtParent extends @stmtparent, AstNode {

/**

* Gets the `i`th child statement of this node.

*

* Note that the precise indices of child statements are considered an implementation detail

* and are subject to change without notice.

*/

Stmt getChildStmt(int i) { stmts(result, _, this, i) }

/**

* Gets a statement that is a child node of this node in the AST.

*/

Stmt getAChildStmt() { result = this.getChildStmt(_) }

/**

* Gets the number of child statements of this node.

*/

int getNumChildStmt() { result = count(this.getAChildStmt()) }

}

/**

* An AST node whose children include declarations.

*/

class DeclParent extends @declparent, AstNode {

/**

* Gets the `i`th child declaration of this node.

*

* Note that the precise indices of declarations are considered an implementation detail

* and are subject to change without notice.

*/

Decl getDecl(int i) { decls(result, _, this, i) }

/**

* Gets a child declaration of this node in the AST.

*/

Decl getADecl() { result = this.getDecl(_) }

/**

* Gets the number of child declarations of this node.

*/

int getNumDecl() { result = count(this.getADecl()) }

}

/**

* An AST node whose children include field declarations.

*

* A field declaration can be in a struct, a function (for parameter or result

* variables), or an interface (in which case it is a method or embedding spec).

*/

class FieldParent extends @fieldparent, AstNode {

/**

* Gets the `i`th field declaration of this node.

*

* Note that the precise indices of field declarations are considered an

* implementation detail and are subject to change without notice.

*/

FieldBase getField(int i) { fields(result, this, i) }

/**

* Gets a child field declaration of this node in the AST.

*/

FieldBase getAField() { result = this.getField(_) }

/**

* Gets the number of child field declarations of this node.

*/

int getNumFields() { result = count(this.getAField()) }

}

/**

* An AST node whose children include type parameter declarations.

*/

class TypeParamDeclParent extends @typeparamdeclparent, AstNode {

/**

* Gets the `i`th type parameter declaration of this node.

*

* Note that the precise indices of type parameters are considered an implementation detail

* and are subject to change without notice.

*/

TypeParamDecl getTypeParameterDecl(int i) { typeparamdecls(result, this, i) }

/**

* Gets a child field of this node in the AST.

*/

TypeParamDecl getATypeParameterDecl() { result = this.getTypeParameterDecl(_) }

}

/**

* An AST node which may induce a scope.

*

* The following nodes may induce scopes:

*

* - files

* - block statements, `if` statements, `switch` statements, `case` clauses, comm clauses, loops

* - function type expressions

*

* Note that functions themselves do not induce a scope, it is their type declaration that induces

* the scope.

*/

class ScopeNode extends @scopenode, AstNode {

/** Gets the scope induced by this node, if any. */

LocalScope getScope() { scopenodes(this, result) }

}