[macOS] use SourceKit to ensure that all public symbols are exported

Makefile

@@ -277,6 +277,10 @@ idocument:
 darwin-style-code:
 	node platform/darwin/scripts/generate-style-code.js
 style-code: darwin-style-code
+
+.PHONY: check-public-symbols
+check-public-symbols:
+	node platform/darwin/scripts/check-public-symbols.js macOS
 endif
 
 #### Linux targets #####################################################

platform/darwin/scripts/check-public-symbols.js

@@ -0,0 +1,83 @@
+#!/usr/bin/env node
+
+'use strict';
+
+const fs = require('fs');
+const path = require('path');
+const execFileSync = require('child_process').execFileSync;
+const _ = require('lodash');
+
+const keyword = /\bMGL_EXPORT\b/;
+
+let scanned = [];
+
+function hasMissingSymbols(os) {
+  let missing = false;
+  let sdk = os === 'iOS' ? 'iphonesimulator' : 'macosx';
+  let sysroot = execFileSync('xcrun', ['--show-sdk-path', '--sdk', sdk]).toString().trim();
+  let umbrellaPath = `platform/${os.toLowerCase()}/src/Mapbox.h`;
+  let docArgs = ['doc', '--objc', umbrellaPath, '--',
+                 '-x', 'objective-c', '-I', 'platform/darwin/src/', '-isysroot', sysroot];
+  let docStr = execFileSync('sourcekitten', docArgs).toString().trim();
+  let docJson = JSON.parse(docStr);
+  _.forEach(docJson, function (result) {
+    _.forEach(result, function (structure, path) {
+      // Prevent multiple scans of the same file.
+      if (scanned.indexOf(path) >= 0) return;
+      scanned.push(path);
+
+      const src = fs.readFileSync(path, 'utf8').split('\n');
+      _.forEach(structure['key.substructure'], function (substructure) {
+        switch (substructure['key.kind']) {
+          case 'sourcekitten.source.lang.objc.decl.class':
+            if (!(keyword.test(src[substructure['key.doc.line'] - 1]) || keyword.test(src[substructure['key.doc.line'] - 2]))) {
+              console.warn(`- missing symbol export for class ${substructure['key.name']} in ${path}:${substructure['key.doc.line']}:${substructure['key.doc.column']}`);
+              missing = true;
+            }
+            break;
+          case 'sourcekitten.source.lang.objc.decl.constant':
+            if (!keyword.test(src[substructure['key.doc.line'] - 1])) {
+              console.warn(`- missing symbol export for constant ${substructure['key.name']} in ${path}:${substructure['key.doc.line']}:${substructure['key.doc.column']}`);
+              missing = true;
+            }
+            break;
+        }
+      });
+    });
+  });
+
+  return missing;
+}
+
+function ensureSourceKittenIsInstalled() {
+  try {
+    execFileSync('which', ['sourcekitten']);
+  } catch (e) {
+    console.log(`Installing SourceKitten via Homebrew…`);
+    execFileSync('brew', ['install', 'sourcekitten']);
+  }
+}
+
+if (process.argv.length < 3) {
+  console.warn(`Usage: ${path.relative(process.cwd(), process.argv[1])} [macOS|iOS] ...`);
+  process.exit(1);
+}
+
+ensureSourceKittenIsInstalled();
+
+let missing = false;
+for (var i = 2; i < process.argv.length; i++) {
+  let os = process.argv[i];
+  if (os == 'iOS' || os == 'macOS') {
+    missing |= hasMissingSymbols(os);
+  } else {
+    console.warn(`Argument must be one of iOS or macOS`);
+    process.exit(1);
+  }
+}
+
+if (missing) {
+  process.exit(1);
+} else {
+  console.warn(`All symbols are correctly exported.`);
+}

platform/macos/scripts/package.sh

@@ -75,3 +75,6 @@ sed -n -e '/^## /,$p' platform/macos/CHANGELOG.md > "${OUTPUT}/CHANGELOG.md"
 
 step "Generating API documentation…"
 make xdocument OUTPUT="${OUTPUT}/documentation"
+
+step "Checking that all public symbols are exported…"
+node platform/darwin/scripts/check-public-symbols.js macOS