Clone engine262 in /engine262

2026-08-18 13:42:51 +00:00 · 2020-09-07 10:19:00 +05:30
parent 7688de2e5c
commit 66c1aeb9e0
313 changed files with 46014 additions and 0 deletions
@@ -0,0 +1,260 @@
+'use strict';
+
+const { relative, resolve } = require('path');
+
+const COMPLETION_PATH = resolve('./src/completion.mjs');
+const ABSTRACT_OPS_PATH = resolve('./src/abstract-ops/all.mjs');
+const VALUE_PATH = resolve('./src/value.mjs');
+
+function fileToImport(file, refPath) {
+  return relative(file.opts.filename, refPath)
+    .replace(/\\/g, '/') // Support building on Windows
+    .replace('../', './');
+}
+
+function findParentStatementPath(path) {
+  while (path && !path.isStatement()) {
+    path = path.parentPath;
+  }
+  return path;
+}
+
+function getEnclosingConditionalExpression(path) {
+  while (path && !path.isStatement()) {
+    if (path.isConditionalExpression()) {
+      return path;
+    }
+    path = path.parentPath;
+  }
+  return null;
+}
+
+module.exports = ({ types: t, template }) => {
+  function createImportCompletion(file) {
+    const r = fileToImport(file, COMPLETION_PATH);
+    return template.ast(`
+      import { Completion } from "${r}";
+    `);
+  }
+
+  function createImportAbruptCompletion(file) {
+    const r = fileToImport(file, COMPLETION_PATH);
+    return template.ast(`
+      import { AbruptCompletion } from "${r}";
+    `);
+  }
+
+  function createImportAssert(file) {
+    const r = fileToImport(file, ABSTRACT_OPS_PATH);
+    return template.ast(`
+      import { Assert } from "${r}";
+    `);
+  }
+
+  function createImportCall(file) {
+    const r = fileToImport(file, ABSTRACT_OPS_PATH);
+    return template.ast(`
+      import { Call } from "${r}";
+    `);
+  }
+
+  function createImportValue(file) {
+    const r = fileToImport(file, VALUE_PATH);
+    return template.ast(`
+      import { Value } from "${r}";
+    `);
+  }
+
+  function addSectionFromComments(path) {
+    if (path.node.leadingComments) {
+      for (const c of path.node.leadingComments) {
+        const lines = c.value.split('\n');
+        for (const line of lines) {
+          if (/#sec/.test(line)) {
+            const section = line.split(' ').find((l) => l.includes('#sec'));
+            const url = section.includes('https') ? section : `https://tc39.es/ecma262/${section}`;
+            path.insertAfter(template.ast(`${path.node.id ? path.node.id.name : path.node.declarations[0].id.name}.section = '${url}';`));
+            return;
+          }
+        }
+      }
+    }
+  }
+
+  const MACROS = {
+    Q: {
+      template: template(`
+      let ID = ARGUMENT;
+      /* istanbul ignore if */
+      if (ID instanceof AbruptCompletion) {
+        return ID;
+      }
+      /* istanbul ignore if */
+      if (ID instanceof Completion) {
+        ID = ID.Value;
+      }
+      `, { preserveComments: true }),
+      imports: ['AbruptCompletion', 'Completion'],
+    },
+    X: {
+      template: template(`
+      let ID = ARGUMENT;
+      Assert(!(ID instanceof AbruptCompletion), SOURCE + ' returned an abrupt completion');
+      /* istanbul ignore if */
+      if (ID instanceof Completion) {
+        ID = ID.Value;
+      }
+      `, { preserveComments: true }),
+      imports: ['Assert', 'Completion', 'AbruptCompletion'],
+    },
+    IfAbruptRejectPromise: {
+      template: template(`
+      /* istanbul ignore if */
+      if (ID instanceof AbruptCompletion) {
+        const hygenicTemp2 = Call(CAPABILITY.Reject, Value.undefined, [ID.Value]);
+        if (hygenicTemp2 instanceof AbruptCompletion) {
+          return hygenicTemp2;
+        }
+        return CAPABILITY.Promise;
+      }
+      /* istanbul ignore if */
+      if (ID instanceof Completion) {
+        ID = ID.Value;
+      }
+      `, { preserveComments: true }),
+      imports: ['Call', 'Value', 'AbruptCompletion', 'Completion'],
+    },
+  };
+  MACROS.ReturnIfAbrupt = MACROS.Q;
+  const MACRO_NAMES = Object.keys(MACROS);
+
+  return {
+    visitor: {
+      Program: {
+        enter(path, state) {
+          state.needed = {};
+        },
+        exit(path, state) {
+          if (state.needed.Completion && !state.file.opts.filename.endsWith('completion.mjs')) {
+            path.node.body.unshift(createImportCompletion(state.file));
+          }
+          if (state.needed.AbruptCompletion && !state.file.opts.filename.endsWith('completion.mjs')) {
+            path.node.body.unshift(createImportAbruptCompletion(state.file));
+          }
+          if (state.needed.Assert) {
+            path.node.body.unshift(createImportAssert(state.file));
+          }
+          if (state.needed.Call) {
+            path.node.body.unshift(createImportCall(state.file));
+          }
+          if (state.needed.Value) {
+            path.node.body.unshift(createImportValue(state.file));
+          }
+        },
+      },
+      CallExpression(path, state) {
+        if (!t.isIdentifier(path.node.callee)) {
+          return;
+        }
+
+        const macroName = path.node.callee.name;
+        if (MACRO_NAMES.includes(macroName)) {
+          const enclosingConditional = getEnclosingConditionalExpression(path);
+          if (enclosingConditional !== null) {
+            if (enclosingConditional.parentPath.isVariableDeclarator()) {
+              const declaration = enclosingConditional.parentPath.parentPath;
+              const id = enclosingConditional.parentPath.get('id');
+              declaration.replaceWithMultiple(template.ast(`
+              let ${id};
+              if (${enclosingConditional.get('test')}) {
+                ${id} = ${enclosingConditional.get('consequent')}
+              } else {
+                ${id} = ${enclosingConditional.get('alternate')}
+              }
+              `));
+              return;
+            } else {
+              throw path.buildCodeFrameError('Macros may not be used within conditional expressions');
+            }
+          }
+
+          const macro = MACROS[macroName];
+          const [argument] = path.node.arguments;
+
+          if (macro === MACROS.Q && (t.isReturnStatement(path.parentPath) || path.parentPath.isArrowFunctionExpression())) {
+            path.replaceWith(path.node.arguments[0]);
+            return;
+          }
+
+          if (path.parentPath.isArrowFunctionExpression()) {
+            throw path.buildCodeFrameError('Macros may not be the sole expression of an arrow function');
+          }
+
+          const statementPath = findParentStatementPath(path);
+
+          macro.imports.forEach((i) => {
+            state.needed[i] = path.scope.getBinding(i) === undefined;
+          });
+
+          if (macro === MACROS.Q && t.isIdentifier(argument)) {
+            const binding = path.scope.getBinding(argument.name);
+            binding.path.parent.kind = 'let';
+            statementPath.insertBefore(template(`
+              /* istanbul ignore if */
+              if (ID instanceof AbruptCompletion) {
+                return ID;
+              }
+              /* istanbul ignore if */
+              if (ID instanceof Completion) {
+                ID = ID.Value;
+              }
+            `, { preserveComments: true })({ ID: argument }));
+            path.replaceWith(argument);
+          } else {
+            if (macro === MACROS.IfAbruptRejectPromise) {
+              const [, capability] = path.node.arguments;
+              if (!t.isIdentifier(argument)) {
+                throw path.get('arguments.0').buildCodeFrameError('First argument to IfAbruptRejectPromise should be an identifier');
+              }
+              if (!t.isIdentifier(capability)) {
+                throw path.get('arguments.1').buildCodeFrameError('Second argument to IfAbruptRejectPromise should be an identifier');
+              }
+              const binding = path.scope.getBinding(argument.name);
+              binding.path.parent.kind = 'let';
+              statementPath.insertBefore(macro.template({ ID: argument, CAPABILITY: capability }));
+              path.remove();
+            } else {
+              const id = statementPath.scope.generateUidIdentifier();
+              const replacement = {
+                ARGUMENT: argument,
+                ID: id,
+              };
+              if (macro === MACROS.X) {
+                replacement.SOURCE = t.stringLiteral(path.get('arguments.0').getSource());
+              }
+              statementPath.insertBefore(macro.template(replacement));
+              path.replaceWith(id);
+            }
+          }
+        } else if (macroName === 'Assert') {
+          path.node.arguments.push(t.stringLiteral(path.get('arguments.0').getSource()));
+        }
+      },
+      SwitchCase(path) {
+        const n = path.node.consequent[0];
+        if (t.isThrowStatement(n) && t.isNewExpression(n.argument) && n.argument.callee.name === 'OutOfRange') {
+          path.node.leadingComments = path.node.leadingComments || [];
+          path.node.leadingComments.push({ type: 'CommentBlock', value: 'istanbul ignore next' });
+        }
+      },
+      FunctionDeclaration(path) {
+        addSectionFromComments(path);
+      },
+      VariableDeclaration(path) {
+        if (path.get('declarations.0.init').isArrowFunctionExpression()) {
+          addSectionFromComments(path);
+        }
+      },
+    },
+  };
+};