Symbols and Declarations

Linking between a node and a symbol is performed by a few functions. One function that is used to bind the SourceFile node to the source file Symbol (in case of an external module) is the addDeclarationToSymbol function

Note : the Symbol for an external module source file is setup as flags : SymbolFlags.ValueModule and name: '"' + removeFileExtension(file.fileName) + '"').

function addDeclarationToSymbol(symbol: Symbol, node: Declaration, symbolFlags: SymbolFlags) {
    symbol.flags |= symbolFlags;

    node.symbol = symbol;

    if (!symbol.declarations) {
        symbol.declarations = [];
    }
    symbol.declarations.push(node);

    if (symbolFlags & SymbolFlags.HasExports && !symbol.exports) {
        symbol.exports = {};
    }

    if (symbolFlags & SymbolFlags.HasMembers && !symbol.members) {
        symbol.members = {};
    }

    if (symbolFlags & SymbolFlags.Value && !symbol.valueDeclaration) {
        symbol.valueDeclaration = node;
    }
}

The important linking portions:

• Creates a link to the Symbol from the AST node (node.symbol).
• Adds the node as one of the declarations of the Symbol (symbol.declarations).

Declaration

Declaration is just a node with an optional name. In types.ts

interface Declaration extends Node {
    _declarationBrand: any;
    name?: DeclarationName;
}