xref: /third_party/typescript/src/compiler/factory/emitNode.ts

import {
    AccessExpression, append, appendIfUnique, Debug, EmitFlags, EmitHelper, EmitNode, getParseTreeNode,
    getSourceFileOfNode, isParseTreeNode, Node, orderedRemoveItem, SnippetElement, some, SourceFile, SourceMapRange,
    SyntaxKind, SynthesizedComment, TextRange, TypeNode
} from "../_namespaces/ts";

/**
 * Associates a node with the current transformation, initializing
 * various transient transformation properties.
 * @internal
 */
export function getOrCreateEmitNode(node: Node): EmitNode {
    if (!node.emitNode) {
        if (isParseTreeNode(node)) {
            // To avoid holding onto transformation artifacts, we keep track of any
            // parse tree node we are annotating. This allows us to clean them up after
            // all transformations have completed.
            if (node.kind === SyntaxKind.SourceFile) {
                return node.emitNode = { annotatedNodes: [node] } as EmitNode;
            }

            const sourceFile = getSourceFileOfNode(getParseTreeNode(getSourceFileOfNode(node))) ?? Debug.fail("Could not determine parsed source file.");
            getOrCreateEmitNode(sourceFile).annotatedNodes!.push(node);
        }

        node.emitNode = {} as EmitNode;
    }
    else {
        Debug.assert(!(node.emitNode.flags & EmitFlags.Immutable), "Invalid attempt to mutate an immutable node.");
    }
    return node.emitNode;
}

/**
 * Clears any `EmitNode` entries from parse-tree nodes.
 * @param sourceFile A source file.
 */
export function disposeEmitNodes(sourceFile: SourceFile | undefined) {
    // During transformation we may need to annotate a parse tree node with transient
    // transformation properties. As parse tree nodes live longer than transformation
    // nodes, we need to make sure we reclaim any memory allocated for custom ranges
    // from these nodes to ensure we do not hold onto entire subtrees just for position
    // information. We also need to reset these nodes to a pre-transformation state
    // for incremental parsing scenarios so that we do not impact later emit.
    const annotatedNodes = getSourceFileOfNode(getParseTreeNode(sourceFile))?.emitNode?.annotatedNodes;
    if (annotatedNodes) {
        for (const node of annotatedNodes) {
            node.emitNode = undefined;
        }
    }
}

/**
 * Sets `EmitFlags.NoComments` on a node and removes any leading and trailing synthetic comments.
 * @internal
 */
export function removeAllComments<T extends Node>(node: T): T {
    const emitNode = getOrCreateEmitNode(node);
    emitNode.flags |= EmitFlags.NoComments;
    emitNode.leadingComments = undefined;
    emitNode.trailingComments = undefined;
    return node;
}

/**
 * Sets flags that control emit behavior of a node.
 */
export function setEmitFlags<T extends Node>(node: T, emitFlags: EmitFlags) {
    getOrCreateEmitNode(node).flags = emitFlags;
    return node;
}

/**
 * Sets flags that control emit behavior of a node.
 * @internal
 */
export function addEmitFlags<T extends Node>(node: T, emitFlags: EmitFlags) {
    const emitNode = getOrCreateEmitNode(node);
    emitNode.flags = emitNode.flags | emitFlags;
    return node;
}

/**
 * Gets a custom text range to use when emitting source maps.
 */
export function getSourceMapRange(node: Node): SourceMapRange {
    return node.emitNode?.sourceMapRange ?? node;
}

/**
 * Sets a custom text range to use when emitting source maps.
 */
export function setSourceMapRange<T extends Node>(node: T, range: SourceMapRange | undefined) {
    getOrCreateEmitNode(node).sourceMapRange = range;
    return node;
}

/**
 * Gets the TextRange to use for source maps for a token of a node.
 */
export function getTokenSourceMapRange(node: Node, token: SyntaxKind): SourceMapRange | undefined {
    return node.emitNode?.tokenSourceMapRanges?.[token];
}

/**
 * Sets the TextRange to use for source maps for a token of a node.
 */
export function setTokenSourceMapRange<T extends Node>(node: T, token: SyntaxKind, range: SourceMapRange | undefined) {
    const emitNode = getOrCreateEmitNode(node);
    const tokenSourceMapRanges = emitNode.tokenSourceMapRanges ?? (emitNode.tokenSourceMapRanges = []);
    tokenSourceMapRanges[token] = range;
    return node;
}

/**
 * Gets a custom text range to use when emitting comments.
 *
 * @internal
 */
export function getStartsOnNewLine(node: Node) {
    return node.emitNode?.startsOnNewLine;
}

/**
 * Sets a custom text range to use when emitting comments.
 *
 * @internal
 */
export function setStartsOnNewLine<T extends Node>(node: T, newLine: boolean) {
    getOrCreateEmitNode(node).startsOnNewLine = newLine;
    return node;
}

/**
 * Gets a custom text range to use when emitting comments.
 */
export function getCommentRange(node: Node): TextRange {
    return node.emitNode?.commentRange ?? node;
}

/**
 * Sets a custom text range to use when emitting comments.
 */
export function setCommentRange<T extends Node>(node: T, range: TextRange) {
    getOrCreateEmitNode(node).commentRange = range;
    return node;
}

export function getSyntheticLeadingComments(node: Node): SynthesizedComment[] | undefined {
    return node.emitNode?.leadingComments;
}

export function setSyntheticLeadingComments<T extends Node>(node: T, comments: SynthesizedComment[] | undefined) {
    getOrCreateEmitNode(node).leadingComments = comments;
    return node;
}

export function addSyntheticLeadingComment<T extends Node>(node: T, kind: SyntaxKind.SingleLineCommentTrivia | SyntaxKind.MultiLineCommentTrivia, text: string, hasTrailingNewLine?: boolean) {
    return setSyntheticLeadingComments(node, append<SynthesizedComment>(getSyntheticLeadingComments(node), { kind, pos: -1, end: -1, hasTrailingNewLine, text }));
}

export function getSyntheticTrailingComments(node: Node): SynthesizedComment[] | undefined {
    return node.emitNode?.trailingComments;
}

export function setSyntheticTrailingComments<T extends Node>(node: T, comments: SynthesizedComment[] | undefined) {
    getOrCreateEmitNode(node).trailingComments = comments;
    return node;
}

export function addSyntheticTrailingComment<T extends Node>(node: T, kind: SyntaxKind.SingleLineCommentTrivia | SyntaxKind.MultiLineCommentTrivia, text: string, hasTrailingNewLine?: boolean) {
    return setSyntheticTrailingComments(node, append<SynthesizedComment>(getSyntheticTrailingComments(node), { kind, pos: -1, end: -1, hasTrailingNewLine, text }));
}

export function moveSyntheticComments<T extends Node>(node: T, original: Node): T {
    setSyntheticLeadingComments(node, getSyntheticLeadingComments(original));
    setSyntheticTrailingComments(node, getSyntheticTrailingComments(original));
    const emit = getOrCreateEmitNode(original);
    emit.leadingComments = undefined;
    emit.trailingComments = undefined;
    return node;
}

/**
 * Gets the constant value to emit for an expression representing an enum.
 */
export function getConstantValue(node: AccessExpression): string | number | undefined {
    return node.emitNode?.constantValue;
}

/**
 * Sets the constant value to emit for an expression.
 */
export function setConstantValue(node: AccessExpression, value: string | number): AccessExpression {
    const emitNode = getOrCreateEmitNode(node);
    emitNode.constantValue = value;
    return node;
}

/**
 * Adds an EmitHelper to a node.
 */
export function addEmitHelper<T extends Node>(node: T, helper: EmitHelper): T {
    const emitNode = getOrCreateEmitNode(node);
    emitNode.helpers = append(emitNode.helpers, helper);
    return node;
}

/**
 * Add EmitHelpers to a node.
 */
export function addEmitHelpers<T extends Node>(node: T, helpers: EmitHelper[] | undefined): T {
    if (some(helpers)) {
        const emitNode = getOrCreateEmitNode(node);
        for (const helper of helpers) {
            emitNode.helpers = appendIfUnique(emitNode.helpers, helper);
        }
    }
    return node;
}

/**
 * Removes an EmitHelper from a node.
 */
export function removeEmitHelper(node: Node, helper: EmitHelper): boolean {
    const helpers = node.emitNode?.helpers;
    if (helpers) {
        return orderedRemoveItem(helpers, helper);
    }
    return false;
}

/**
 * Gets the EmitHelpers of a node.
 */
export function getEmitHelpers(node: Node): EmitHelper[] | undefined {
    return node.emitNode?.helpers;
}

/**
 * Moves matching emit helpers from a source node to a target node.
 */
export function moveEmitHelpers(source: Node, target: Node, predicate: (helper: EmitHelper) => boolean) {
    const sourceEmitNode = source.emitNode;
    const sourceEmitHelpers = sourceEmitNode && sourceEmitNode.helpers;
    if (!some(sourceEmitHelpers)) return;

    const targetEmitNode = getOrCreateEmitNode(target);
    let helpersRemoved = 0;
    for (let i = 0; i < sourceEmitHelpers.length; i++) {
        const helper = sourceEmitHelpers[i];
        if (predicate(helper)) {
            helpersRemoved++;
            targetEmitNode.helpers = appendIfUnique(targetEmitNode.helpers, helper);
        }
        else if (helpersRemoved > 0) {
            sourceEmitHelpers[i - helpersRemoved] = helper;
        }
    }

    if (helpersRemoved > 0) {
        sourceEmitHelpers.length -= helpersRemoved;
    }
}

/**
 * Gets the SnippetElement of a node.
 *
 * @internal
 */
export function getSnippetElement(node: Node): SnippetElement | undefined {
    return node.emitNode?.snippetElement;
}

/**
 * Sets the SnippetElement of a node.
 *
 * @internal
 */
export function setSnippetElement<T extends Node>(node: T, snippet: SnippetElement): T {
    const emitNode = getOrCreateEmitNode(node);
    emitNode.snippetElement = snippet;
    return node;
}

/** @internal */
export function ignoreSourceNewlines<T extends Node>(node: T): T {
    getOrCreateEmitNode(node).flags |= EmitFlags.IgnoreSourceNewlines;
    return node;
}

/** @internal */
export function setTypeNode<T extends Node>(node: T, type: TypeNode): T {
    const emitNode = getOrCreateEmitNode(node);
    emitNode.typeNode = type;
    return node;
}

/** @internal */
export function getTypeNode<T extends Node>(node: T): TypeNode | undefined {
    return node.emitNode?.typeNode;
}