mirror of https://github.com/webpack/webpack.git
414 lines
13 KiB
JavaScript
414 lines
13 KiB
JavaScript
/*
|
|
MIT License http://www.opensource.org/licenses/mit-license.php
|
|
Author Tobias Koppers @sokra
|
|
*/
|
|
|
|
"use strict";
|
|
|
|
const {
|
|
harmonySpecifierTag
|
|
} = require("../dependencies/HarmonyImportDependencyParserPlugin");
|
|
const PureExpressionDependency = require("../dependencies/PureExpressionDependency");
|
|
const InnerGraph = require("./InnerGraph");
|
|
|
|
/** @typedef {import("estree").ClassDeclaration} ClassDeclarationNode */
|
|
/** @typedef {import("estree").ClassExpression} ClassExpressionNode */
|
|
/** @typedef {import("estree").Node} Node */
|
|
/** @typedef {import("estree").VariableDeclarator} VariableDeclaratorNode */
|
|
/** @typedef {import("../Compiler")} Compiler */
|
|
/** @typedef {import("../Dependency")} Dependency */
|
|
/** @typedef {import("../dependencies/HarmonyImportSpecifierDependency")} HarmonyImportSpecifierDependency */
|
|
/** @typedef {import("../javascript/JavascriptParser")} JavascriptParser */
|
|
/** @typedef {import("./InnerGraph").InnerGraph} InnerGraph */
|
|
/** @typedef {import("./InnerGraph").TopLevelSymbol} TopLevelSymbol */
|
|
|
|
const { topLevelSymbolTag } = InnerGraph;
|
|
|
|
/**
|
|
* @param {any} expr an expression
|
|
* @param {JavascriptParser} parser the parser
|
|
* @param {number} commentsStartPos source position from which annotation comments are checked
|
|
* @returns {boolean} true, when the expression is pure
|
|
*/
|
|
const isPure = (expr, parser, commentsStartPos) => {
|
|
switch (expr.type) {
|
|
case "Identifier":
|
|
return (
|
|
parser.isVariableDefined(expr.name) ||
|
|
parser.getTagData(expr.name, harmonySpecifierTag)
|
|
);
|
|
|
|
case "ClassDeclaration":
|
|
case "ClassExpression":
|
|
if (expr.body.type !== "ClassBody") return false;
|
|
if (expr.superClass && !isPure(expr.superClass, parser, expr.range[0])) {
|
|
return false;
|
|
}
|
|
return expr.body.body.every(item => {
|
|
switch (item.type) {
|
|
case "ClassProperty":
|
|
// TODO add test case once acorn supports it
|
|
// Currently this is not parsable
|
|
if (item.static) return isPure(item.value, parser, item.range[0]);
|
|
break;
|
|
}
|
|
return true;
|
|
});
|
|
|
|
case "FunctionDeclaration":
|
|
case "FunctionExpression":
|
|
case "ArrowFunctionExpression":
|
|
case "Literal":
|
|
return true;
|
|
|
|
case "ConditionalExpression":
|
|
return (
|
|
isPure(expr.test, parser, commentsStartPos) &&
|
|
isPure(expr.consequent, parser, expr.test.range[1]) &&
|
|
isPure(expr.alternate, parser, expr.consequent.range[1])
|
|
);
|
|
|
|
case "SequenceExpression":
|
|
return expr.expressions.every(expr => {
|
|
const pureFlag = isPure(expr, parser, commentsStartPos);
|
|
commentsStartPos = expr.range[1];
|
|
return pureFlag;
|
|
});
|
|
|
|
case "CallExpression": {
|
|
const pureFlag =
|
|
expr.range[0] - commentsStartPos > 12 &&
|
|
parser
|
|
.getComments([commentsStartPos, expr.range[0]])
|
|
.some(
|
|
comment =>
|
|
comment.type === "Block" &&
|
|
/^\s*(#|@)__PURE__\s*$/.test(comment.value)
|
|
);
|
|
if (!pureFlag) return false;
|
|
commentsStartPos = expr.callee.range[1];
|
|
return expr.arguments.every(arg => {
|
|
if (arg.type === "SpreadElement") return false;
|
|
const pureFlag = isPure(arg, parser, commentsStartPos);
|
|
commentsStartPos = arg.range[1];
|
|
return pureFlag;
|
|
});
|
|
}
|
|
}
|
|
return false;
|
|
};
|
|
|
|
class InnerGraphPlugin {
|
|
/**
|
|
* @param {Compiler} compiler webpack compiler
|
|
* @returns {void}
|
|
*/
|
|
apply(compiler) {
|
|
compiler.hooks.compilation.tap(
|
|
"InnerGraphPlugin",
|
|
(compilation, { normalModuleFactory }) => {
|
|
const logger = compilation.getLogger("webpack.InnerGraphPlugin");
|
|
|
|
compilation.dependencyTemplates.set(
|
|
PureExpressionDependency,
|
|
new PureExpressionDependency.Template()
|
|
);
|
|
|
|
/**
|
|
* @param {JavascriptParser} parser the parser
|
|
* @param {Object} parserOptions options
|
|
* @returns {void}
|
|
*/
|
|
const handler = (parser, parserOptions) => {
|
|
const onUsageSuper = sup => {
|
|
InnerGraph.onUsage(parser.state, usedByExports => {
|
|
switch (usedByExports) {
|
|
case undefined:
|
|
case true:
|
|
return;
|
|
default: {
|
|
const dep = new PureExpressionDependency(sup.range);
|
|
dep.loc = sup.loc;
|
|
dep.usedByExports = usedByExports;
|
|
parser.state.module.addDependency(dep);
|
|
break;
|
|
}
|
|
}
|
|
});
|
|
};
|
|
|
|
parser.hooks.program.tap("InnerGraphPlugin", () => {
|
|
InnerGraph.enable(parser.state);
|
|
});
|
|
|
|
parser.hooks.finish.tap("InnerGraphPlugin", () => {
|
|
if (!InnerGraph.isEnabled(parser.state)) return;
|
|
|
|
logger.time("infer dependency usage");
|
|
InnerGraph.inferDependencyUsage(parser.state);
|
|
logger.timeAggregate("infer dependency usage");
|
|
});
|
|
|
|
// During prewalking the following datastructures are filled with
|
|
// nodes that have a TopLevelSymbol assigned and
|
|
// variables are tagged with the assigned TopLevelSymbol
|
|
|
|
// We differ 3 types of nodes:
|
|
// 1. full statements (export default, function declaration)
|
|
// 2. classes (class declaration, class expression)
|
|
// 3. variable declarators (const x = ...)
|
|
|
|
/** @type {WeakMap<Node, TopLevelSymbol>} */
|
|
const statementWithTopLevelSymbol = new WeakMap();
|
|
/** @type {WeakMap<Node, Node>} */
|
|
const statementPurePart = new WeakMap();
|
|
|
|
/** @type {WeakMap<ClassExpressionNode | ClassDeclarationNode, TopLevelSymbol>} */
|
|
const classWithTopLevelSymbol = new WeakMap();
|
|
|
|
/** @type {WeakMap<VariableDeclaratorNode, TopLevelSymbol>} */
|
|
const declWithTopLevelSymbol = new WeakMap();
|
|
/** @type {WeakSet<VariableDeclaratorNode>} */
|
|
const pureDeclarators = new WeakSet();
|
|
|
|
// The following hooks are used during prewalking:
|
|
|
|
parser.hooks.preStatement.tap("InnerGraphPlugin", statement => {
|
|
if (!InnerGraph.isEnabled(parser.state)) return;
|
|
|
|
if (parser.scope.topLevelScope === true) {
|
|
if (statement.type === "FunctionDeclaration") {
|
|
const name = statement.id ? statement.id.name : "*default*";
|
|
const fn = InnerGraph.tagTopLevelSymbol(parser, name);
|
|
statementWithTopLevelSymbol.set(statement, fn);
|
|
return true;
|
|
}
|
|
}
|
|
});
|
|
|
|
parser.hooks.blockPreStatement.tap("InnerGraphPlugin", statement => {
|
|
if (!InnerGraph.isEnabled(parser.state)) return;
|
|
|
|
if (parser.scope.topLevelScope === true) {
|
|
if (statement.type === "ClassDeclaration") {
|
|
const name = statement.id ? statement.id.name : "*default*";
|
|
const fn = InnerGraph.tagTopLevelSymbol(parser, name);
|
|
classWithTopLevelSymbol.set(statement, fn);
|
|
return true;
|
|
}
|
|
if (statement.type === "ExportDefaultDeclaration") {
|
|
const name = "*default*";
|
|
const fn = InnerGraph.tagTopLevelSymbol(parser, name);
|
|
const decl = statement.declaration;
|
|
if (
|
|
decl.type === "ClassExpression" ||
|
|
decl.type === "ClassDeclaration"
|
|
) {
|
|
classWithTopLevelSymbol.set(decl, fn);
|
|
} else if (isPure(decl, parser, decl.range[1])) {
|
|
statementWithTopLevelSymbol.set(statement, fn);
|
|
if (
|
|
!decl.type.endsWith("FunctionExpression") &&
|
|
!decl.type.endsWith("Declaration") &&
|
|
decl.type !== "Literal"
|
|
) {
|
|
statementPurePart.set(statement, decl);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
});
|
|
|
|
parser.hooks.preDeclarator.tap(
|
|
"InnerGraphPlugin",
|
|
(decl, statement) => {
|
|
if (!InnerGraph.isEnabled(parser.state)) return;
|
|
if (
|
|
parser.scope.topLevelScope === true &&
|
|
decl.init &&
|
|
decl.id.type === "Identifier"
|
|
) {
|
|
const name = decl.id.name;
|
|
if (decl.init.type === "ClassExpression") {
|
|
const fn = InnerGraph.tagTopLevelSymbol(parser, name);
|
|
classWithTopLevelSymbol.set(decl.init, fn);
|
|
} else if (isPure(decl.init, parser, decl.id.range[1])) {
|
|
const fn = InnerGraph.tagTopLevelSymbol(parser, name);
|
|
declWithTopLevelSymbol.set(decl, fn);
|
|
if (
|
|
!decl.init.type.endsWith("FunctionExpression") &&
|
|
decl.init.type !== "Literal"
|
|
) {
|
|
pureDeclarators.add(decl);
|
|
}
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
);
|
|
|
|
// During real walking we set the TopLevelSymbol state to the assigned
|
|
// TopLevelSymbol by using the fill datastructures.
|
|
|
|
// In addition to tracking TopLevelSymbols, we sometimes need to
|
|
// add a PureExpressionDependency. This is needed to skip execution
|
|
// of pure expressions, even when they are not dropped due to
|
|
// minimizing. Otherwise symbols used there might not exist anymore
|
|
// as they are removed as unused by this optimization
|
|
|
|
// When we find a reference to a TopLevelSymbol, we register a
|
|
// TopLevelSymbol dependency from TopLevelSymbol in state to the
|
|
// referenced TopLevelSymbol. This way we get a graph of all
|
|
// TopLevelSymbols.
|
|
|
|
// The following hooks are called during walking:
|
|
|
|
parser.hooks.statement.tap("InnerGraphPlugin", statement => {
|
|
if (!InnerGraph.isEnabled(parser.state)) return;
|
|
if (parser.scope.topLevelScope === true) {
|
|
InnerGraph.setTopLevelSymbol(parser.state, undefined);
|
|
|
|
const fn = statementWithTopLevelSymbol.get(statement);
|
|
if (fn) {
|
|
InnerGraph.setTopLevelSymbol(parser.state, fn);
|
|
const purePart = statementPurePart.get(statement);
|
|
if (purePart) {
|
|
InnerGraph.onUsage(parser.state, usedByExports => {
|
|
switch (usedByExports) {
|
|
case undefined:
|
|
case true:
|
|
return;
|
|
default: {
|
|
const dep = new PureExpressionDependency(
|
|
purePart.range
|
|
);
|
|
dep.loc = statement.loc;
|
|
dep.usedByExports = usedByExports;
|
|
parser.state.module.addDependency(dep);
|
|
break;
|
|
}
|
|
}
|
|
});
|
|
}
|
|
}
|
|
}
|
|
});
|
|
|
|
parser.hooks.classExtendsExpression.tap(
|
|
"InnerGraphPlugin",
|
|
(expr, statement) => {
|
|
if (!InnerGraph.isEnabled(parser.state)) return;
|
|
if (parser.scope.topLevelScope === true) {
|
|
const fn = classWithTopLevelSymbol.get(statement);
|
|
if (
|
|
fn &&
|
|
isPure(
|
|
expr,
|
|
parser,
|
|
statement.id ? statement.id.range[1] : statement.range[0]
|
|
)
|
|
) {
|
|
InnerGraph.setTopLevelSymbol(parser.state, fn);
|
|
onUsageSuper(expr);
|
|
}
|
|
}
|
|
}
|
|
);
|
|
|
|
parser.hooks.classBodyElement.tap(
|
|
"InnerGraphPlugin",
|
|
(element, statement) => {
|
|
if (!InnerGraph.isEnabled(parser.state)) return;
|
|
if (parser.scope.topLevelScope === true) {
|
|
const fn = classWithTopLevelSymbol.get(statement);
|
|
if (fn) {
|
|
if (element.type === "MethodDefinition") {
|
|
InnerGraph.setTopLevelSymbol(parser.state, fn);
|
|
} else if (
|
|
element.type === "ClassProperty" &&
|
|
!element.static
|
|
) {
|
|
// TODO add test case once acorn supports it
|
|
// Currently this is not parsable
|
|
InnerGraph.setTopLevelSymbol(parser.state, fn);
|
|
} else {
|
|
InnerGraph.setTopLevelSymbol(parser.state, undefined);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
);
|
|
|
|
parser.hooks.declarator.tap("InnerGraphPlugin", (decl, statement) => {
|
|
if (!InnerGraph.isEnabled(parser.state)) return;
|
|
const fn = declWithTopLevelSymbol.get(decl);
|
|
|
|
if (fn) {
|
|
InnerGraph.setTopLevelSymbol(parser.state, fn);
|
|
if (pureDeclarators.has(decl)) {
|
|
if (decl.init.type === "ClassExpression") {
|
|
if (decl.init.superClass) {
|
|
onUsageSuper(decl.init.superClass);
|
|
}
|
|
} else {
|
|
InnerGraph.onUsage(parser.state, usedByExports => {
|
|
switch (usedByExports) {
|
|
case undefined:
|
|
case true:
|
|
return;
|
|
default: {
|
|
const dep = new PureExpressionDependency(
|
|
decl.init.range
|
|
);
|
|
dep.loc = decl.loc;
|
|
dep.usedByExports = usedByExports;
|
|
parser.state.module.addDependency(dep);
|
|
break;
|
|
}
|
|
}
|
|
});
|
|
}
|
|
}
|
|
parser.walkExpression(decl.init);
|
|
InnerGraph.setTopLevelSymbol(parser.state, undefined);
|
|
return true;
|
|
}
|
|
});
|
|
|
|
parser.hooks.expression
|
|
.for(topLevelSymbolTag)
|
|
.tap("InnerGraphPlugin", () => {
|
|
const topLevelSymbol = /** @type {TopLevelSymbol} */ (parser.currentTagData);
|
|
const currentTopLevelSymbol = InnerGraph.getTopLevelSymbol(
|
|
parser.state
|
|
);
|
|
InnerGraph.addUsage(
|
|
parser.state,
|
|
topLevelSymbol,
|
|
currentTopLevelSymbol || true
|
|
);
|
|
});
|
|
parser.hooks.assign
|
|
.for(topLevelSymbolTag)
|
|
.tap("InnerGraphPlugin", expr => {
|
|
if (!InnerGraph.isEnabled(parser.state)) return;
|
|
if (expr.operator === "=") return true;
|
|
});
|
|
};
|
|
normalModuleFactory.hooks.parser
|
|
.for("javascript/auto")
|
|
.tap("InnerGraphPlugin", handler);
|
|
normalModuleFactory.hooks.parser
|
|
.for("javascript/esm")
|
|
.tap("InnerGraphPlugin", handler);
|
|
|
|
compilation.hooks.finishModules.tap("InnerGraphPlugin", () => {
|
|
logger.timeAggregateEnd("infer dependency usage");
|
|
});
|
|
}
|
|
);
|
|
}
|
|
}
|
|
|
|
module.exports = InnerGraphPlugin;
|