1 //=- LocalizationChecker.cpp -------------------------------------*- C++ -*-==//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 //  This file defines a set of checks for localizability including:
11 //  1) A checker that warns about uses of non-localized NSStrings passed to
12 //     UI methods expecting localized strings
13 //  2) A syntactic checker that warns against the bad practice of
14 //     not including a comment in NSLocalizedString macros.
15 //
16 //===----------------------------------------------------------------------===//
17 
18 #include "ClangSACheckers.h"
19 #include "clang/AST/Attr.h"
20 #include "clang/AST/Decl.h"
21 #include "clang/AST/DeclObjC.h"
22 #include "clang/AST/RecursiveASTVisitor.h"
23 #include "clang/AST/StmtVisitor.h"
24 #include "clang/Lex/Lexer.h"
25 #include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
26 #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
27 #include "clang/StaticAnalyzer/Core/Checker.h"
28 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
29 #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
30 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
31 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
32 #include "llvm/Support/Unicode.h"
33 
34 using namespace clang;
35 using namespace ento;
36 
37 namespace {
38 struct LocalizedState {
39 private:
40   enum Kind { NonLocalized, Localized } K;
41   LocalizedState(Kind InK) : K(InK) {}
42 
43 public:
44   bool isLocalized() const { return K == Localized; }
45   bool isNonLocalized() const { return K == NonLocalized; }
46 
47   static LocalizedState getLocalized() { return LocalizedState(Localized); }
48   static LocalizedState getNonLocalized() {
49     return LocalizedState(NonLocalized);
50   }
51 
52   // Overload the == operator
53   bool operator==(const LocalizedState &X) const { return K == X.K; }
54 
55   // LLVMs equivalent of a hash function
56   void Profile(llvm::FoldingSetNodeID &ID) const { ID.AddInteger(K); }
57 };
58 
59 class NonLocalizedStringChecker
60     : public Checker<check::PostCall, check::PreObjCMessage,
61                      check::PostObjCMessage,
62                      check::PostStmt<ObjCStringLiteral>> {
63 
64   mutable std::unique_ptr<BugType> BT;
65 
66   // Methods that require a localized string
67   mutable llvm::DenseMap<const IdentifierInfo *,
68                          llvm::DenseMap<Selector, uint8_t>> UIMethods;
69   // Methods that return a localized string
70   mutable llvm::SmallSet<std::pair<const IdentifierInfo *, Selector>, 12> LSM;
71   // C Functions that return a localized string
72   mutable llvm::SmallSet<const IdentifierInfo *, 5> LSF;
73 
74   void initUIMethods(ASTContext &Ctx) const;
75   void initLocStringsMethods(ASTContext &Ctx) const;
76 
77   bool hasNonLocalizedState(SVal S, CheckerContext &C) const;
78   bool hasLocalizedState(SVal S, CheckerContext &C) const;
79   void setNonLocalizedState(SVal S, CheckerContext &C) const;
80   void setLocalizedState(SVal S, CheckerContext &C) const;
81 
82   bool isAnnotatedAsLocalized(const Decl *D) const;
83   void reportLocalizationError(SVal S, const ObjCMethodCall &M,
84                                CheckerContext &C, int argumentNumber = 0) const;
85 
86   int getLocalizedArgumentForSelector(const IdentifierInfo *Receiver,
87                                       Selector S) const;
88 
89 public:
90   NonLocalizedStringChecker();
91 
92   // When this parameter is set to true, the checker assumes all
93   // methods that return NSStrings are unlocalized. Thus, more false
94   // positives will be reported.
95   DefaultBool IsAggressive;
96 
97   void checkPreObjCMessage(const ObjCMethodCall &msg, CheckerContext &C) const;
98   void checkPostObjCMessage(const ObjCMethodCall &msg, CheckerContext &C) const;
99   void checkPostStmt(const ObjCStringLiteral *SL, CheckerContext &C) const;
100   void checkPostCall(const CallEvent &Call, CheckerContext &C) const;
101 };
102 
103 } // end anonymous namespace
104 
105 REGISTER_MAP_WITH_PROGRAMSTATE(LocalizedMemMap, const MemRegion *,
106                                LocalizedState)
107 
108 NonLocalizedStringChecker::NonLocalizedStringChecker() {
109   BT.reset(new BugType(this, "Unlocalizable string",
110                        "Localizability Issue (Apple)"));
111 }
112 
113 namespace {
114 class NonLocalizedStringBRVisitor final
115     : public BugReporterVisitorImpl<NonLocalizedStringBRVisitor> {
116 
117   const MemRegion *NonLocalizedString;
118   bool Satisfied;
119 
120 public:
121   NonLocalizedStringBRVisitor(const MemRegion *NonLocalizedString)
122       : NonLocalizedString(NonLocalizedString), Satisfied(false) {
123         assert(NonLocalizedString);
124   }
125 
126   PathDiagnosticPiece *VisitNode(const ExplodedNode *Succ,
127                                  const ExplodedNode *Pred,
128                                  BugReporterContext &BRC,
129                                  BugReport &BR) override;
130 
131   void Profile(llvm::FoldingSetNodeID &ID) const override {
132     ID.Add(NonLocalizedString);
133   }
134 };
135 } // End anonymous namespace.
136 
137 #define NEW_RECEIVER(receiver)                                                 \
138   llvm::DenseMap<Selector, uint8_t> &receiver##M =                             \
139       UIMethods.insert({&Ctx.Idents.get(#receiver),                            \
140                         llvm::DenseMap<Selector, uint8_t>()})                  \
141           .first->second;
142 #define ADD_NULLARY_METHOD(receiver, method, argument)                         \
143   receiver##M.insert(                                                          \
144       {Ctx.Selectors.getNullarySelector(&Ctx.Idents.get(#method)), argument});
145 #define ADD_UNARY_METHOD(receiver, method, argument)                           \
146   receiver##M.insert(                                                          \
147       {Ctx.Selectors.getUnarySelector(&Ctx.Idents.get(#method)), argument});
148 #define ADD_METHOD(receiver, method_list, count, argument)                     \
149   receiver##M.insert({Ctx.Selectors.getSelector(count, method_list), argument});
150 
151 /// Initializes a list of methods that require a localized string
152 /// Format: {"ClassName", {{"selectorName:", LocStringArg#}, ...}, ...}
153 void NonLocalizedStringChecker::initUIMethods(ASTContext &Ctx) const {
154   if (!UIMethods.empty())
155     return;
156 
157   // UI Methods
158   NEW_RECEIVER(UISearchDisplayController)
159   ADD_UNARY_METHOD(UISearchDisplayController, setSearchResultsTitle, 0)
160 
161   NEW_RECEIVER(UITabBarItem)
162   IdentifierInfo *initWithTitleUITabBarItemTag[] = {
163       &Ctx.Idents.get("initWithTitle"), &Ctx.Idents.get("image"),
164       &Ctx.Idents.get("tag")};
165   ADD_METHOD(UITabBarItem, initWithTitleUITabBarItemTag, 3, 0)
166   IdentifierInfo *initWithTitleUITabBarItemImage[] = {
167       &Ctx.Idents.get("initWithTitle"), &Ctx.Idents.get("image"),
168       &Ctx.Idents.get("selectedImage")};
169   ADD_METHOD(UITabBarItem, initWithTitleUITabBarItemImage, 3, 0)
170 
171   NEW_RECEIVER(NSDockTile)
172   ADD_UNARY_METHOD(NSDockTile, setBadgeLabel, 0)
173 
174   NEW_RECEIVER(NSStatusItem)
175   ADD_UNARY_METHOD(NSStatusItem, setTitle, 0)
176   ADD_UNARY_METHOD(NSStatusItem, setToolTip, 0)
177 
178   NEW_RECEIVER(UITableViewRowAction)
179   IdentifierInfo *rowActionWithStyleUITableViewRowAction[] = {
180       &Ctx.Idents.get("rowActionWithStyle"), &Ctx.Idents.get("title"),
181       &Ctx.Idents.get("handler")};
182   ADD_METHOD(UITableViewRowAction, rowActionWithStyleUITableViewRowAction, 3, 1)
183   ADD_UNARY_METHOD(UITableViewRowAction, setTitle, 0)
184 
185   NEW_RECEIVER(NSBox)
186   ADD_UNARY_METHOD(NSBox, setTitle, 0)
187 
188   NEW_RECEIVER(NSButton)
189   ADD_UNARY_METHOD(NSButton, setTitle, 0)
190   ADD_UNARY_METHOD(NSButton, setAlternateTitle, 0)
191 
192   NEW_RECEIVER(NSSavePanel)
193   ADD_UNARY_METHOD(NSSavePanel, setPrompt, 0)
194   ADD_UNARY_METHOD(NSSavePanel, setTitle, 0)
195   ADD_UNARY_METHOD(NSSavePanel, setNameFieldLabel, 0)
196   ADD_UNARY_METHOD(NSSavePanel, setNameFieldStringValue, 0)
197   ADD_UNARY_METHOD(NSSavePanel, setMessage, 0)
198 
199   NEW_RECEIVER(UIPrintInfo)
200   ADD_UNARY_METHOD(UIPrintInfo, setJobName, 0)
201 
202   NEW_RECEIVER(NSTabViewItem)
203   ADD_UNARY_METHOD(NSTabViewItem, setLabel, 0)
204   ADD_UNARY_METHOD(NSTabViewItem, setToolTip, 0)
205 
206   NEW_RECEIVER(NSBrowser)
207   IdentifierInfo *setTitleNSBrowser[] = {&Ctx.Idents.get("setTitle"),
208                                          &Ctx.Idents.get("ofColumn")};
209   ADD_METHOD(NSBrowser, setTitleNSBrowser, 2, 0)
210 
211   NEW_RECEIVER(UIAccessibilityElement)
212   ADD_UNARY_METHOD(UIAccessibilityElement, setAccessibilityLabel, 0)
213   ADD_UNARY_METHOD(UIAccessibilityElement, setAccessibilityHint, 0)
214   ADD_UNARY_METHOD(UIAccessibilityElement, setAccessibilityValue, 0)
215 
216   NEW_RECEIVER(UIAlertAction)
217   IdentifierInfo *actionWithTitleUIAlertAction[] = {
218       &Ctx.Idents.get("actionWithTitle"), &Ctx.Idents.get("style"),
219       &Ctx.Idents.get("handler")};
220   ADD_METHOD(UIAlertAction, actionWithTitleUIAlertAction, 3, 0)
221 
222   NEW_RECEIVER(NSPopUpButton)
223   ADD_UNARY_METHOD(NSPopUpButton, addItemWithTitle, 0)
224   IdentifierInfo *insertItemWithTitleNSPopUpButton[] = {
225       &Ctx.Idents.get("insertItemWithTitle"), &Ctx.Idents.get("atIndex")};
226   ADD_METHOD(NSPopUpButton, insertItemWithTitleNSPopUpButton, 2, 0)
227   ADD_UNARY_METHOD(NSPopUpButton, removeItemWithTitle, 0)
228   ADD_UNARY_METHOD(NSPopUpButton, selectItemWithTitle, 0)
229   ADD_UNARY_METHOD(NSPopUpButton, setTitle, 0)
230 
231   NEW_RECEIVER(NSTableViewRowAction)
232   IdentifierInfo *rowActionWithStyleNSTableViewRowAction[] = {
233       &Ctx.Idents.get("rowActionWithStyle"), &Ctx.Idents.get("title"),
234       &Ctx.Idents.get("handler")};
235   ADD_METHOD(NSTableViewRowAction, rowActionWithStyleNSTableViewRowAction, 3, 1)
236   ADD_UNARY_METHOD(NSTableViewRowAction, setTitle, 0)
237 
238   NEW_RECEIVER(NSImage)
239   ADD_UNARY_METHOD(NSImage, setAccessibilityDescription, 0)
240 
241   NEW_RECEIVER(NSUserActivity)
242   ADD_UNARY_METHOD(NSUserActivity, setTitle, 0)
243 
244   NEW_RECEIVER(NSPathControlItem)
245   ADD_UNARY_METHOD(NSPathControlItem, setTitle, 0)
246 
247   NEW_RECEIVER(NSCell)
248   ADD_UNARY_METHOD(NSCell, initTextCell, 0)
249   ADD_UNARY_METHOD(NSCell, setTitle, 0)
250   ADD_UNARY_METHOD(NSCell, setStringValue, 0)
251 
252   NEW_RECEIVER(NSPathControl)
253   ADD_UNARY_METHOD(NSPathControl, setPlaceholderString, 0)
254 
255   NEW_RECEIVER(UIAccessibility)
256   ADD_UNARY_METHOD(UIAccessibility, setAccessibilityLabel, 0)
257   ADD_UNARY_METHOD(UIAccessibility, setAccessibilityHint, 0)
258   ADD_UNARY_METHOD(UIAccessibility, setAccessibilityValue, 0)
259 
260   NEW_RECEIVER(NSTableColumn)
261   ADD_UNARY_METHOD(NSTableColumn, setTitle, 0)
262   ADD_UNARY_METHOD(NSTableColumn, setHeaderToolTip, 0)
263 
264   NEW_RECEIVER(NSSegmentedControl)
265   IdentifierInfo *setLabelNSSegmentedControl[] = {
266       &Ctx.Idents.get("setLabel"), &Ctx.Idents.get("forSegment")};
267   ADD_METHOD(NSSegmentedControl, setLabelNSSegmentedControl, 2, 0)
268 
269   NEW_RECEIVER(NSButtonCell)
270   ADD_UNARY_METHOD(NSButtonCell, setTitle, 0)
271   ADD_UNARY_METHOD(NSButtonCell, setAlternateTitle, 0)
272 
273   NEW_RECEIVER(NSSliderCell)
274   ADD_UNARY_METHOD(NSSliderCell, setTitle, 0)
275 
276   NEW_RECEIVER(NSControl)
277   ADD_UNARY_METHOD(NSControl, setStringValue, 0)
278 
279   NEW_RECEIVER(NSAccessibility)
280   ADD_UNARY_METHOD(NSAccessibility, setAccessibilityValueDescription, 0)
281   ADD_UNARY_METHOD(NSAccessibility, setAccessibilityLabel, 0)
282   ADD_UNARY_METHOD(NSAccessibility, setAccessibilityTitle, 0)
283   ADD_UNARY_METHOD(NSAccessibility, setAccessibilityPlaceholderValue, 0)
284   ADD_UNARY_METHOD(NSAccessibility, setAccessibilityHelp, 0)
285 
286   NEW_RECEIVER(NSMatrix)
287   IdentifierInfo *setToolTipNSMatrix[] = {&Ctx.Idents.get("setToolTip"),
288                                           &Ctx.Idents.get("forCell")};
289   ADD_METHOD(NSMatrix, setToolTipNSMatrix, 2, 0)
290 
291   NEW_RECEIVER(NSPrintPanel)
292   ADD_UNARY_METHOD(NSPrintPanel, setDefaultButtonTitle, 0)
293 
294   NEW_RECEIVER(UILocalNotification)
295   ADD_UNARY_METHOD(UILocalNotification, setAlertBody, 0)
296   ADD_UNARY_METHOD(UILocalNotification, setAlertAction, 0)
297   ADD_UNARY_METHOD(UILocalNotification, setAlertTitle, 0)
298 
299   NEW_RECEIVER(NSSlider)
300   ADD_UNARY_METHOD(NSSlider, setTitle, 0)
301 
302   NEW_RECEIVER(UIMenuItem)
303   IdentifierInfo *initWithTitleUIMenuItem[] = {&Ctx.Idents.get("initWithTitle"),
304                                                &Ctx.Idents.get("action")};
305   ADD_METHOD(UIMenuItem, initWithTitleUIMenuItem, 2, 0)
306   ADD_UNARY_METHOD(UIMenuItem, setTitle, 0)
307 
308   NEW_RECEIVER(UIAlertController)
309   IdentifierInfo *alertControllerWithTitleUIAlertController[] = {
310       &Ctx.Idents.get("alertControllerWithTitle"), &Ctx.Idents.get("message"),
311       &Ctx.Idents.get("preferredStyle")};
312   ADD_METHOD(UIAlertController, alertControllerWithTitleUIAlertController, 3, 1)
313   ADD_UNARY_METHOD(UIAlertController, setTitle, 0)
314   ADD_UNARY_METHOD(UIAlertController, setMessage, 0)
315 
316   NEW_RECEIVER(UIApplicationShortcutItem)
317   IdentifierInfo *initWithTypeUIApplicationShortcutItemIcon[] = {
318       &Ctx.Idents.get("initWithType"), &Ctx.Idents.get("localizedTitle"),
319       &Ctx.Idents.get("localizedSubtitle"), &Ctx.Idents.get("icon"),
320       &Ctx.Idents.get("userInfo")};
321   ADD_METHOD(UIApplicationShortcutItem,
322              initWithTypeUIApplicationShortcutItemIcon, 5, 1)
323   IdentifierInfo *initWithTypeUIApplicationShortcutItem[] = {
324       &Ctx.Idents.get("initWithType"), &Ctx.Idents.get("localizedTitle")};
325   ADD_METHOD(UIApplicationShortcutItem, initWithTypeUIApplicationShortcutItem,
326              2, 1)
327 
328   NEW_RECEIVER(UIActionSheet)
329   IdentifierInfo *initWithTitleUIActionSheet[] = {
330       &Ctx.Idents.get("initWithTitle"), &Ctx.Idents.get("delegate"),
331       &Ctx.Idents.get("cancelButtonTitle"),
332       &Ctx.Idents.get("destructiveButtonTitle"),
333       &Ctx.Idents.get("otherButtonTitles")};
334   ADD_METHOD(UIActionSheet, initWithTitleUIActionSheet, 5, 0)
335   ADD_UNARY_METHOD(UIActionSheet, addButtonWithTitle, 0)
336   ADD_UNARY_METHOD(UIActionSheet, setTitle, 0)
337 
338   NEW_RECEIVER(NSURLSessionTask)
339   ADD_UNARY_METHOD(NSURLSessionTask, setTaskDescription, 0)
340 
341   NEW_RECEIVER(UIAccessibilityCustomAction)
342   IdentifierInfo *initWithNameUIAccessibilityCustomAction[] = {
343       &Ctx.Idents.get("initWithName"), &Ctx.Idents.get("target"),
344       &Ctx.Idents.get("selector")};
345   ADD_METHOD(UIAccessibilityCustomAction,
346              initWithNameUIAccessibilityCustomAction, 3, 0)
347   ADD_UNARY_METHOD(UIAccessibilityCustomAction, setName, 0)
348 
349   NEW_RECEIVER(UISearchBar)
350   ADD_UNARY_METHOD(UISearchBar, setText, 0)
351   ADD_UNARY_METHOD(UISearchBar, setPrompt, 0)
352   ADD_UNARY_METHOD(UISearchBar, setPlaceholder, 0)
353 
354   NEW_RECEIVER(UIBarItem)
355   ADD_UNARY_METHOD(UIBarItem, setTitle, 0)
356 
357   NEW_RECEIVER(UITextView)
358   ADD_UNARY_METHOD(UITextView, setText, 0)
359 
360   NEW_RECEIVER(NSView)
361   ADD_UNARY_METHOD(NSView, setToolTip, 0)
362 
363   NEW_RECEIVER(NSTextField)
364   ADD_UNARY_METHOD(NSTextField, setPlaceholderString, 0)
365 
366   NEW_RECEIVER(NSAttributedString)
367   ADD_UNARY_METHOD(NSAttributedString, initWithString, 0)
368   IdentifierInfo *initWithStringNSAttributedString[] = {
369       &Ctx.Idents.get("initWithString"), &Ctx.Idents.get("attributes")};
370   ADD_METHOD(NSAttributedString, initWithStringNSAttributedString, 2, 0)
371 
372   NEW_RECEIVER(NSText)
373   ADD_UNARY_METHOD(NSText, setString, 0)
374 
375   NEW_RECEIVER(UIKeyCommand)
376   IdentifierInfo *keyCommandWithInputUIKeyCommand[] = {
377       &Ctx.Idents.get("keyCommandWithInput"), &Ctx.Idents.get("modifierFlags"),
378       &Ctx.Idents.get("action"), &Ctx.Idents.get("discoverabilityTitle")};
379   ADD_METHOD(UIKeyCommand, keyCommandWithInputUIKeyCommand, 4, 3)
380   ADD_UNARY_METHOD(UIKeyCommand, setDiscoverabilityTitle, 0)
381 
382   NEW_RECEIVER(UILabel)
383   ADD_UNARY_METHOD(UILabel, setText, 0)
384 
385   NEW_RECEIVER(NSAlert)
386   IdentifierInfo *alertWithMessageTextNSAlert[] = {
387       &Ctx.Idents.get("alertWithMessageText"), &Ctx.Idents.get("defaultButton"),
388       &Ctx.Idents.get("alternateButton"), &Ctx.Idents.get("otherButton"),
389       &Ctx.Idents.get("informativeTextWithFormat")};
390   ADD_METHOD(NSAlert, alertWithMessageTextNSAlert, 5, 0)
391   ADD_UNARY_METHOD(NSAlert, addButtonWithTitle, 0)
392   ADD_UNARY_METHOD(NSAlert, setMessageText, 0)
393   ADD_UNARY_METHOD(NSAlert, setInformativeText, 0)
394   ADD_UNARY_METHOD(NSAlert, setHelpAnchor, 0)
395 
396   NEW_RECEIVER(UIMutableApplicationShortcutItem)
397   ADD_UNARY_METHOD(UIMutableApplicationShortcutItem, setLocalizedTitle, 0)
398   ADD_UNARY_METHOD(UIMutableApplicationShortcutItem, setLocalizedSubtitle, 0)
399 
400   NEW_RECEIVER(UIButton)
401   IdentifierInfo *setTitleUIButton[] = {&Ctx.Idents.get("setTitle"),
402                                         &Ctx.Idents.get("forState")};
403   ADD_METHOD(UIButton, setTitleUIButton, 2, 0)
404 
405   NEW_RECEIVER(NSWindow)
406   ADD_UNARY_METHOD(NSWindow, setTitle, 0)
407   IdentifierInfo *minFrameWidthWithTitleNSWindow[] = {
408       &Ctx.Idents.get("minFrameWidthWithTitle"), &Ctx.Idents.get("styleMask")};
409   ADD_METHOD(NSWindow, minFrameWidthWithTitleNSWindow, 2, 0)
410   ADD_UNARY_METHOD(NSWindow, setMiniwindowTitle, 0)
411 
412   NEW_RECEIVER(NSPathCell)
413   ADD_UNARY_METHOD(NSPathCell, setPlaceholderString, 0)
414 
415   NEW_RECEIVER(UIDocumentMenuViewController)
416   IdentifierInfo *addOptionWithTitleUIDocumentMenuViewController[] = {
417       &Ctx.Idents.get("addOptionWithTitle"), &Ctx.Idents.get("image"),
418       &Ctx.Idents.get("order"), &Ctx.Idents.get("handler")};
419   ADD_METHOD(UIDocumentMenuViewController,
420              addOptionWithTitleUIDocumentMenuViewController, 4, 0)
421 
422   NEW_RECEIVER(UINavigationItem)
423   ADD_UNARY_METHOD(UINavigationItem, initWithTitle, 0)
424   ADD_UNARY_METHOD(UINavigationItem, setTitle, 0)
425   ADD_UNARY_METHOD(UINavigationItem, setPrompt, 0)
426 
427   NEW_RECEIVER(UIAlertView)
428   IdentifierInfo *initWithTitleUIAlertView[] = {
429       &Ctx.Idents.get("initWithTitle"), &Ctx.Idents.get("message"),
430       &Ctx.Idents.get("delegate"), &Ctx.Idents.get("cancelButtonTitle"),
431       &Ctx.Idents.get("otherButtonTitles")};
432   ADD_METHOD(UIAlertView, initWithTitleUIAlertView, 5, 0)
433   ADD_UNARY_METHOD(UIAlertView, addButtonWithTitle, 0)
434   ADD_UNARY_METHOD(UIAlertView, setTitle, 0)
435   ADD_UNARY_METHOD(UIAlertView, setMessage, 0)
436 
437   NEW_RECEIVER(NSFormCell)
438   ADD_UNARY_METHOD(NSFormCell, initTextCell, 0)
439   ADD_UNARY_METHOD(NSFormCell, setTitle, 0)
440   ADD_UNARY_METHOD(NSFormCell, setPlaceholderString, 0)
441 
442   NEW_RECEIVER(NSUserNotification)
443   ADD_UNARY_METHOD(NSUserNotification, setTitle, 0)
444   ADD_UNARY_METHOD(NSUserNotification, setSubtitle, 0)
445   ADD_UNARY_METHOD(NSUserNotification, setInformativeText, 0)
446   ADD_UNARY_METHOD(NSUserNotification, setActionButtonTitle, 0)
447   ADD_UNARY_METHOD(NSUserNotification, setOtherButtonTitle, 0)
448   ADD_UNARY_METHOD(NSUserNotification, setResponsePlaceholder, 0)
449 
450   NEW_RECEIVER(NSToolbarItem)
451   ADD_UNARY_METHOD(NSToolbarItem, setLabel, 0)
452   ADD_UNARY_METHOD(NSToolbarItem, setPaletteLabel, 0)
453   ADD_UNARY_METHOD(NSToolbarItem, setToolTip, 0)
454 
455   NEW_RECEIVER(NSProgress)
456   ADD_UNARY_METHOD(NSProgress, setLocalizedDescription, 0)
457   ADD_UNARY_METHOD(NSProgress, setLocalizedAdditionalDescription, 0)
458 
459   NEW_RECEIVER(NSSegmentedCell)
460   IdentifierInfo *setLabelNSSegmentedCell[] = {&Ctx.Idents.get("setLabel"),
461                                                &Ctx.Idents.get("forSegment")};
462   ADD_METHOD(NSSegmentedCell, setLabelNSSegmentedCell, 2, 0)
463   IdentifierInfo *setToolTipNSSegmentedCell[] = {&Ctx.Idents.get("setToolTip"),
464                                                  &Ctx.Idents.get("forSegment")};
465   ADD_METHOD(NSSegmentedCell, setToolTipNSSegmentedCell, 2, 0)
466 
467   NEW_RECEIVER(NSUndoManager)
468   ADD_UNARY_METHOD(NSUndoManager, setActionName, 0)
469   ADD_UNARY_METHOD(NSUndoManager, undoMenuTitleForUndoActionName, 0)
470   ADD_UNARY_METHOD(NSUndoManager, redoMenuTitleForUndoActionName, 0)
471 
472   NEW_RECEIVER(NSMenuItem)
473   IdentifierInfo *initWithTitleNSMenuItem[] = {
474       &Ctx.Idents.get("initWithTitle"), &Ctx.Idents.get("action"),
475       &Ctx.Idents.get("keyEquivalent")};
476   ADD_METHOD(NSMenuItem, initWithTitleNSMenuItem, 3, 0)
477   ADD_UNARY_METHOD(NSMenuItem, setTitle, 0)
478   ADD_UNARY_METHOD(NSMenuItem, setToolTip, 0)
479 
480   NEW_RECEIVER(NSPopUpButtonCell)
481   IdentifierInfo *initTextCellNSPopUpButtonCell[] = {
482       &Ctx.Idents.get("initTextCell"), &Ctx.Idents.get("pullsDown")};
483   ADD_METHOD(NSPopUpButtonCell, initTextCellNSPopUpButtonCell, 2, 0)
484   ADD_UNARY_METHOD(NSPopUpButtonCell, addItemWithTitle, 0)
485   IdentifierInfo *insertItemWithTitleNSPopUpButtonCell[] = {
486       &Ctx.Idents.get("insertItemWithTitle"), &Ctx.Idents.get("atIndex")};
487   ADD_METHOD(NSPopUpButtonCell, insertItemWithTitleNSPopUpButtonCell, 2, 0)
488   ADD_UNARY_METHOD(NSPopUpButtonCell, removeItemWithTitle, 0)
489   ADD_UNARY_METHOD(NSPopUpButtonCell, selectItemWithTitle, 0)
490   ADD_UNARY_METHOD(NSPopUpButtonCell, setTitle, 0)
491 
492   NEW_RECEIVER(NSViewController)
493   ADD_UNARY_METHOD(NSViewController, setTitle, 0)
494 
495   NEW_RECEIVER(NSMenu)
496   ADD_UNARY_METHOD(NSMenu, initWithTitle, 0)
497   IdentifierInfo *insertItemWithTitleNSMenu[] = {
498       &Ctx.Idents.get("insertItemWithTitle"), &Ctx.Idents.get("action"),
499       &Ctx.Idents.get("keyEquivalent"), &Ctx.Idents.get("atIndex")};
500   ADD_METHOD(NSMenu, insertItemWithTitleNSMenu, 4, 0)
501   IdentifierInfo *addItemWithTitleNSMenu[] = {
502       &Ctx.Idents.get("addItemWithTitle"), &Ctx.Idents.get("action"),
503       &Ctx.Idents.get("keyEquivalent")};
504   ADD_METHOD(NSMenu, addItemWithTitleNSMenu, 3, 0)
505   ADD_UNARY_METHOD(NSMenu, setTitle, 0)
506 
507   NEW_RECEIVER(UIMutableUserNotificationAction)
508   ADD_UNARY_METHOD(UIMutableUserNotificationAction, setTitle, 0)
509 
510   NEW_RECEIVER(NSForm)
511   ADD_UNARY_METHOD(NSForm, addEntry, 0)
512   IdentifierInfo *insertEntryNSForm[] = {&Ctx.Idents.get("insertEntry"),
513                                          &Ctx.Idents.get("atIndex")};
514   ADD_METHOD(NSForm, insertEntryNSForm, 2, 0)
515 
516   NEW_RECEIVER(NSTextFieldCell)
517   ADD_UNARY_METHOD(NSTextFieldCell, setPlaceholderString, 0)
518 
519   NEW_RECEIVER(NSUserNotificationAction)
520   IdentifierInfo *actionWithIdentifierNSUserNotificationAction[] = {
521       &Ctx.Idents.get("actionWithIdentifier"), &Ctx.Idents.get("title")};
522   ADD_METHOD(NSUserNotificationAction,
523              actionWithIdentifierNSUserNotificationAction, 2, 1)
524 
525   NEW_RECEIVER(NSURLSession)
526   ADD_UNARY_METHOD(NSURLSession, setSessionDescription, 0)
527 
528   NEW_RECEIVER(UITextField)
529   ADD_UNARY_METHOD(UITextField, setText, 0)
530   ADD_UNARY_METHOD(UITextField, setPlaceholder, 0)
531 
532   NEW_RECEIVER(UIBarButtonItem)
533   IdentifierInfo *initWithTitleUIBarButtonItem[] = {
534       &Ctx.Idents.get("initWithTitle"), &Ctx.Idents.get("style"),
535       &Ctx.Idents.get("target"), &Ctx.Idents.get("action")};
536   ADD_METHOD(UIBarButtonItem, initWithTitleUIBarButtonItem, 4, 0)
537 
538   NEW_RECEIVER(UIViewController)
539   ADD_UNARY_METHOD(UIViewController, setTitle, 0)
540 
541   NEW_RECEIVER(UISegmentedControl)
542   IdentifierInfo *insertSegmentWithTitleUISegmentedControl[] = {
543       &Ctx.Idents.get("insertSegmentWithTitle"), &Ctx.Idents.get("atIndex"),
544       &Ctx.Idents.get("animated")};
545   ADD_METHOD(UISegmentedControl, insertSegmentWithTitleUISegmentedControl, 3, 0)
546   IdentifierInfo *setTitleUISegmentedControl[] = {
547       &Ctx.Idents.get("setTitle"), &Ctx.Idents.get("forSegmentAtIndex")};
548   ADD_METHOD(UISegmentedControl, setTitleUISegmentedControl, 2, 0)
549 }
550 
551 #define LSF_INSERT(function_name) LSF.insert(&Ctx.Idents.get(function_name));
552 #define LSM_INSERT_NULLARY(receiver, method_name)                              \
553   LSM.insert({&Ctx.Idents.get(receiver), Ctx.Selectors.getNullarySelector(     \
554                                              &Ctx.Idents.get(method_name))});
555 #define LSM_INSERT_UNARY(receiver, method_name)                                \
556   LSM.insert({&Ctx.Idents.get(receiver),                                       \
557               Ctx.Selectors.getUnarySelector(&Ctx.Idents.get(method_name))});
558 #define LSM_INSERT_SELECTOR(receiver, method_list, arguments)                  \
559   LSM.insert({&Ctx.Idents.get(receiver),                                       \
560               Ctx.Selectors.getSelector(arguments, method_list)});
561 
562 /// Initializes a list of methods and C functions that return a localized string
563 void NonLocalizedStringChecker::initLocStringsMethods(ASTContext &Ctx) const {
564   if (!LSM.empty())
565     return;
566 
567   IdentifierInfo *LocalizedStringMacro[] = {
568       &Ctx.Idents.get("localizedStringForKey"), &Ctx.Idents.get("value"),
569       &Ctx.Idents.get("table")};
570   LSM_INSERT_SELECTOR("NSBundle", LocalizedStringMacro, 3)
571   LSM_INSERT_UNARY("NSDateFormatter", "stringFromDate")
572   IdentifierInfo *LocalizedStringFromDate[] = {
573       &Ctx.Idents.get("localizedStringFromDate"), &Ctx.Idents.get("dateStyle"),
574       &Ctx.Idents.get("timeStyle")};
575   LSM_INSERT_SELECTOR("NSDateFormatter", LocalizedStringFromDate, 3)
576   LSM_INSERT_UNARY("NSNumberFormatter", "stringFromNumber")
577   LSM_INSERT_NULLARY("UITextField", "text")
578   LSM_INSERT_NULLARY("UITextView", "text")
579   LSM_INSERT_NULLARY("UILabel", "text")
580 
581   LSF_INSERT("CFDateFormatterCreateStringWithDate");
582   LSF_INSERT("CFDateFormatterCreateStringWithAbsoluteTime");
583   LSF_INSERT("CFNumberFormatterCreateStringWithNumber");
584 }
585 
586 /// Checks to see if the method / function declaration includes
587 /// __attribute__((annotate("returns_localized_nsstring")))
588 bool NonLocalizedStringChecker::isAnnotatedAsLocalized(const Decl *D) const {
589   if (!D)
590     return false;
591   return std::any_of(
592       D->specific_attr_begin<AnnotateAttr>(),
593       D->specific_attr_end<AnnotateAttr>(), [](const AnnotateAttr *Ann) {
594         return Ann->getAnnotation() == "returns_localized_nsstring";
595       });
596 }
597 
598 /// Returns true if the given SVal is marked as Localized in the program state
599 bool NonLocalizedStringChecker::hasLocalizedState(SVal S,
600                                                   CheckerContext &C) const {
601   const MemRegion *mt = S.getAsRegion();
602   if (mt) {
603     const LocalizedState *LS = C.getState()->get<LocalizedMemMap>(mt);
604     if (LS && LS->isLocalized())
605       return true;
606   }
607   return false;
608 }
609 
610 /// Returns true if the given SVal is marked as NonLocalized in the program
611 /// state
612 bool NonLocalizedStringChecker::hasNonLocalizedState(SVal S,
613                                                      CheckerContext &C) const {
614   const MemRegion *mt = S.getAsRegion();
615   if (mt) {
616     const LocalizedState *LS = C.getState()->get<LocalizedMemMap>(mt);
617     if (LS && LS->isNonLocalized())
618       return true;
619   }
620   return false;
621 }
622 
623 /// Marks the given SVal as Localized in the program state
624 void NonLocalizedStringChecker::setLocalizedState(const SVal S,
625                                                   CheckerContext &C) const {
626   const MemRegion *mt = S.getAsRegion();
627   if (mt) {
628     ProgramStateRef State =
629         C.getState()->set<LocalizedMemMap>(mt, LocalizedState::getLocalized());
630     C.addTransition(State);
631   }
632 }
633 
634 /// Marks the given SVal as NonLocalized in the program state
635 void NonLocalizedStringChecker::setNonLocalizedState(const SVal S,
636                                                      CheckerContext &C) const {
637   const MemRegion *mt = S.getAsRegion();
638   if (mt) {
639     ProgramStateRef State = C.getState()->set<LocalizedMemMap>(
640         mt, LocalizedState::getNonLocalized());
641     C.addTransition(State);
642   }
643 }
644 
645 
646 static bool isDebuggingName(std::string name) {
647   return StringRef(name).lower().find("debug") != StringRef::npos;
648 }
649 
650 /// Returns true when, heuristically, the analyzer may be analyzing debugging
651 /// code. We use this to suppress localization diagnostics in un-localized user
652 /// interfaces that are only used for debugging and are therefore not user
653 /// facing.
654 static bool isDebuggingContext(CheckerContext &C) {
655   const Decl *D = C.getCurrentAnalysisDeclContext()->getDecl();
656   if (!D)
657     return false;
658 
659   if (auto *ND = dyn_cast<NamedDecl>(D)) {
660     if (isDebuggingName(ND->getNameAsString()))
661       return true;
662   }
663 
664   const DeclContext *DC = D->getDeclContext();
665 
666   if (auto *CD = dyn_cast<ObjCContainerDecl>(DC)) {
667     if (isDebuggingName(CD->getNameAsString()))
668       return true;
669   }
670 
671   return false;
672 }
673 
674 
675 /// Reports a localization error for the passed in method call and SVal
676 void NonLocalizedStringChecker::reportLocalizationError(
677     SVal S, const ObjCMethodCall &M, CheckerContext &C,
678     int argumentNumber) const {
679 
680   // Don't warn about localization errors in classes and methods that
681   // may be debug code.
682   if (isDebuggingContext(C))
683     return;
684 
685   ExplodedNode *ErrNode = C.getPredecessor();
686   static CheckerProgramPointTag Tag("NonLocalizedStringChecker",
687                                     "UnlocalizedString");
688   ErrNode = C.addTransition(C.getState(), C.getPredecessor(), &Tag);
689 
690   if (!ErrNode)
691     return;
692 
693   // Generate the bug report.
694   std::unique_ptr<BugReport> R(new BugReport(
695       *BT, "User-facing text should use localized string macro", ErrNode));
696   if (argumentNumber) {
697     R->addRange(M.getArgExpr(argumentNumber - 1)->getSourceRange());
698   } else {
699     R->addRange(M.getSourceRange());
700   }
701   R->markInteresting(S);
702 
703   const MemRegion *StringRegion = S.getAsRegion();
704   if (StringRegion)
705     R->addVisitor(llvm::make_unique<NonLocalizedStringBRVisitor>(StringRegion));
706 
707   C.emitReport(std::move(R));
708 }
709 
710 /// Returns the argument number requiring localized string if it exists
711 /// otherwise, returns -1
712 int NonLocalizedStringChecker::getLocalizedArgumentForSelector(
713     const IdentifierInfo *Receiver, Selector S) const {
714   auto method = UIMethods.find(Receiver);
715 
716   if (method == UIMethods.end())
717     return -1;
718 
719   auto argumentIterator = method->getSecond().find(S);
720 
721   if (argumentIterator == method->getSecond().end())
722     return -1;
723 
724   int argumentNumber = argumentIterator->getSecond();
725   return argumentNumber;
726 }
727 
728 /// Check if the string being passed in has NonLocalized state
729 void NonLocalizedStringChecker::checkPreObjCMessage(const ObjCMethodCall &msg,
730                                                     CheckerContext &C) const {
731   initUIMethods(C.getASTContext());
732 
733   const ObjCInterfaceDecl *OD = msg.getReceiverInterface();
734   if (!OD)
735     return;
736   const IdentifierInfo *odInfo = OD->getIdentifier();
737 
738   Selector S = msg.getSelector();
739 
740   std::string SelectorString = S.getAsString();
741   StringRef SelectorName = SelectorString;
742   assert(!SelectorName.empty());
743 
744   if (odInfo->isStr("NSString")) {
745     // Handle the case where the receiver is an NSString
746     // These special NSString methods draw to the screen
747 
748     if (!(SelectorName.startswith("drawAtPoint") ||
749           SelectorName.startswith("drawInRect") ||
750           SelectorName.startswith("drawWithRect")))
751       return;
752 
753     SVal svTitle = msg.getReceiverSVal();
754 
755     bool isNonLocalized = hasNonLocalizedState(svTitle, C);
756 
757     if (isNonLocalized) {
758       reportLocalizationError(svTitle, msg, C);
759     }
760   }
761 
762   int argumentNumber = getLocalizedArgumentForSelector(odInfo, S);
763   // Go up each hierarchy of superclasses and their protocols
764   while (argumentNumber < 0 && OD->getSuperClass() != nullptr) {
765     for (const auto *P : OD->all_referenced_protocols()) {
766       argumentNumber = getLocalizedArgumentForSelector(P->getIdentifier(), S);
767       if (argumentNumber >= 0)
768         break;
769     }
770     if (argumentNumber < 0) {
771       OD = OD->getSuperClass();
772       argumentNumber = getLocalizedArgumentForSelector(OD->getIdentifier(), S);
773     }
774   }
775 
776   if (argumentNumber < 0) // There was no match in UIMethods
777     return;
778 
779   SVal svTitle = msg.getArgSVal(argumentNumber);
780 
781   if (const ObjCStringRegion *SR =
782           dyn_cast_or_null<ObjCStringRegion>(svTitle.getAsRegion())) {
783     StringRef stringValue =
784         SR->getObjCStringLiteral()->getString()->getString();
785     if ((stringValue.trim().size() == 0 && stringValue.size() > 0) ||
786         stringValue.empty())
787       return;
788     if (!IsAggressive && llvm::sys::unicode::columnWidthUTF8(stringValue) < 2)
789       return;
790   }
791 
792   bool isNonLocalized = hasNonLocalizedState(svTitle, C);
793 
794   if (isNonLocalized) {
795     reportLocalizationError(svTitle, msg, C, argumentNumber + 1);
796   }
797 }
798 
799 static inline bool isNSStringType(QualType T, ASTContext &Ctx) {
800 
801   const ObjCObjectPointerType *PT = T->getAs<ObjCObjectPointerType>();
802   if (!PT)
803     return false;
804 
805   ObjCInterfaceDecl *Cls = PT->getObjectType()->getInterface();
806   if (!Cls)
807     return false;
808 
809   IdentifierInfo *ClsName = Cls->getIdentifier();
810 
811   // FIXME: Should we walk the chain of classes?
812   return ClsName == &Ctx.Idents.get("NSString") ||
813          ClsName == &Ctx.Idents.get("NSMutableString");
814 }
815 
816 /// Marks a string being returned by any call as localized
817 /// if it is in LocStringFunctions (LSF) or the function is annotated.
818 /// Otherwise, we mark it as NonLocalized (Aggressive) or
819 /// NonLocalized only if it is not backed by a SymRegion (Non-Aggressive),
820 /// basically leaving only string literals as NonLocalized.
821 void NonLocalizedStringChecker::checkPostCall(const CallEvent &Call,
822                                               CheckerContext &C) const {
823   initLocStringsMethods(C.getASTContext());
824 
825   if (!Call.getOriginExpr())
826     return;
827 
828   // Anything that takes in a localized NSString as an argument
829   // and returns an NSString will be assumed to be returning a
830   // localized NSString. (Counter: Incorrectly combining two LocalizedStrings)
831   const QualType RT = Call.getResultType();
832   if (isNSStringType(RT, C.getASTContext())) {
833     for (unsigned i = 0; i < Call.getNumArgs(); ++i) {
834       SVal argValue = Call.getArgSVal(i);
835       if (hasLocalizedState(argValue, C)) {
836         SVal sv = Call.getReturnValue();
837         setLocalizedState(sv, C);
838         return;
839       }
840     }
841   }
842 
843   const Decl *D = Call.getDecl();
844   if (!D)
845     return;
846 
847   const IdentifierInfo *Identifier = Call.getCalleeIdentifier();
848 
849   SVal sv = Call.getReturnValue();
850   if (isAnnotatedAsLocalized(D) || LSF.count(Identifier) != 0) {
851     setLocalizedState(sv, C);
852   } else if (isNSStringType(RT, C.getASTContext()) &&
853              !hasLocalizedState(sv, C)) {
854     if (IsAggressive) {
855       setNonLocalizedState(sv, C);
856     } else {
857       const SymbolicRegion *SymReg =
858           dyn_cast_or_null<SymbolicRegion>(sv.getAsRegion());
859       if (!SymReg)
860         setNonLocalizedState(sv, C);
861     }
862   }
863 }
864 
865 /// Marks a string being returned by an ObjC method as localized
866 /// if it is in LocStringMethods or the method is annotated
867 void NonLocalizedStringChecker::checkPostObjCMessage(const ObjCMethodCall &msg,
868                                                      CheckerContext &C) const {
869   initLocStringsMethods(C.getASTContext());
870 
871   if (!msg.isInstanceMessage())
872     return;
873 
874   const ObjCInterfaceDecl *OD = msg.getReceiverInterface();
875   if (!OD)
876     return;
877   const IdentifierInfo *odInfo = OD->getIdentifier();
878 
879   Selector S = msg.getSelector();
880   std::string SelectorName = S.getAsString();
881 
882   std::pair<const IdentifierInfo *, Selector> MethodDescription = {odInfo, S};
883 
884   if (LSM.count(MethodDescription) || isAnnotatedAsLocalized(msg.getDecl())) {
885     SVal sv = msg.getReturnValue();
886     setLocalizedState(sv, C);
887   }
888 }
889 
890 /// Marks all empty string literals as localized
891 void NonLocalizedStringChecker::checkPostStmt(const ObjCStringLiteral *SL,
892                                               CheckerContext &C) const {
893   SVal sv = C.getSVal(SL);
894   setNonLocalizedState(sv, C);
895 }
896 
897 PathDiagnosticPiece *
898 NonLocalizedStringBRVisitor::VisitNode(const ExplodedNode *Succ,
899                                        const ExplodedNode *Pred,
900                                        BugReporterContext &BRC, BugReport &BR) {
901   if (Satisfied)
902     return nullptr;
903 
904   Optional<StmtPoint> Point = Succ->getLocation().getAs<StmtPoint>();
905   if (!Point.hasValue())
906     return nullptr;
907 
908   auto *LiteralExpr = dyn_cast<ObjCStringLiteral>(Point->getStmt());
909   if (!LiteralExpr)
910     return nullptr;
911 
912   ProgramStateRef State = Succ->getState();
913   SVal LiteralSVal = State->getSVal(LiteralExpr, Succ->getLocationContext());
914   if (LiteralSVal.getAsRegion() != NonLocalizedString)
915     return nullptr;
916 
917   Satisfied = true;
918 
919   PathDiagnosticLocation L =
920       PathDiagnosticLocation::create(*Point, BRC.getSourceManager());
921 
922   if (!L.isValid() || !L.asLocation().isValid())
923     return nullptr;
924 
925   auto *Piece = new PathDiagnosticEventPiece(L,
926       "Non-localized string literal here");
927   Piece->addRange(LiteralExpr->getSourceRange());
928 
929   return Piece;
930 }
931 
932 namespace {
933 class EmptyLocalizationContextChecker
934     : public Checker<check::ASTDecl<ObjCImplementationDecl>> {
935 
936   // A helper class, which walks the AST
937   class MethodCrawler : public ConstStmtVisitor<MethodCrawler> {
938     const ObjCMethodDecl *MD;
939     BugReporter &BR;
940     AnalysisManager &Mgr;
941     const CheckerBase *Checker;
942     LocationOrAnalysisDeclContext DCtx;
943 
944   public:
945     MethodCrawler(const ObjCMethodDecl *InMD, BugReporter &InBR,
946                   const CheckerBase *Checker, AnalysisManager &InMgr,
947                   AnalysisDeclContext *InDCtx)
948         : MD(InMD), BR(InBR), Mgr(InMgr), Checker(Checker), DCtx(InDCtx) {}
949 
950     void VisitStmt(const Stmt *S) { VisitChildren(S); }
951 
952     void VisitObjCMessageExpr(const ObjCMessageExpr *ME);
953 
954     void reportEmptyContextError(const ObjCMessageExpr *M) const;
955 
956     void VisitChildren(const Stmt *S) {
957       for (const Stmt *Child : S->children()) {
958         if (Child)
959           this->Visit(Child);
960       }
961     }
962   };
963 
964 public:
965   void checkASTDecl(const ObjCImplementationDecl *D, AnalysisManager &Mgr,
966                     BugReporter &BR) const;
967 };
968 } // end anonymous namespace
969 
970 void EmptyLocalizationContextChecker::checkASTDecl(
971     const ObjCImplementationDecl *D, AnalysisManager &Mgr,
972     BugReporter &BR) const {
973 
974   for (const ObjCMethodDecl *M : D->methods()) {
975     AnalysisDeclContext *DCtx = Mgr.getAnalysisDeclContext(M);
976 
977     const Stmt *Body = M->getBody();
978     assert(Body);
979 
980     MethodCrawler MC(M->getCanonicalDecl(), BR, this, Mgr, DCtx);
981     MC.VisitStmt(Body);
982   }
983 }
984 
985 /// This check attempts to match these macros, assuming they are defined as
986 /// follows:
987 ///
988 /// #define NSLocalizedString(key, comment) \
989 /// [[NSBundle mainBundle] localizedStringForKey:(key) value:@"" table:nil]
990 /// #define NSLocalizedStringFromTable(key, tbl, comment) \
991 /// [[NSBundle mainBundle] localizedStringForKey:(key) value:@"" table:(tbl)]
992 /// #define NSLocalizedStringFromTableInBundle(key, tbl, bundle, comment) \
993 /// [bundle localizedStringForKey:(key) value:@"" table:(tbl)]
994 /// #define NSLocalizedStringWithDefaultValue(key, tbl, bundle, val, comment)
995 ///
996 /// We cannot use the path sensitive check because the macro argument we are
997 /// checking for (comment) is not used and thus not present in the AST,
998 /// so we use Lexer on the original macro call and retrieve the value of
999 /// the comment. If it's empty or nil, we raise a warning.
1000 void EmptyLocalizationContextChecker::MethodCrawler::VisitObjCMessageExpr(
1001     const ObjCMessageExpr *ME) {
1002 
1003   const ObjCInterfaceDecl *OD = ME->getReceiverInterface();
1004   if (!OD)
1005     return;
1006 
1007   const IdentifierInfo *odInfo = OD->getIdentifier();
1008 
1009   if (!(odInfo->isStr("NSBundle") &&
1010         ME->getSelector().getAsString() ==
1011             "localizedStringForKey:value:table:")) {
1012     return;
1013   }
1014 
1015   SourceRange R = ME->getSourceRange();
1016   if (!R.getBegin().isMacroID())
1017     return;
1018 
1019   // getImmediateMacroCallerLoc gets the location of the immediate macro
1020   // caller, one level up the stack toward the initial macro typed into the
1021   // source, so SL should point to the NSLocalizedString macro.
1022   SourceLocation SL =
1023       Mgr.getSourceManager().getImmediateMacroCallerLoc(R.getBegin());
1024   std::pair<FileID, unsigned> SLInfo =
1025       Mgr.getSourceManager().getDecomposedLoc(SL);
1026 
1027   SrcMgr::SLocEntry SE = Mgr.getSourceManager().getSLocEntry(SLInfo.first);
1028 
1029   // If NSLocalizedString macro is wrapped in another macro, we need to
1030   // unwrap the expansion until we get to the NSLocalizedStringMacro.
1031   while (SE.isExpansion()) {
1032     SL = SE.getExpansion().getSpellingLoc();
1033     SLInfo = Mgr.getSourceManager().getDecomposedLoc(SL);
1034     SE = Mgr.getSourceManager().getSLocEntry(SLInfo.first);
1035   }
1036 
1037   llvm::MemoryBuffer *BF = SE.getFile().getContentCache()->getRawBuffer();
1038   Lexer TheLexer(SL, LangOptions(), BF->getBufferStart(),
1039                  BF->getBufferStart() + SLInfo.second, BF->getBufferEnd());
1040 
1041   Token I;
1042   Token Result;    // This will hold the token just before the last ')'
1043   int p_count = 0; // This is for parenthesis matching
1044   while (!TheLexer.LexFromRawLexer(I)) {
1045     if (I.getKind() == tok::l_paren)
1046       ++p_count;
1047     if (I.getKind() == tok::r_paren) {
1048       if (p_count == 1)
1049         break;
1050       --p_count;
1051     }
1052     Result = I;
1053   }
1054 
1055   if (isAnyIdentifier(Result.getKind())) {
1056     if (Result.getRawIdentifier().equals("nil")) {
1057       reportEmptyContextError(ME);
1058       return;
1059     }
1060   }
1061 
1062   if (!isStringLiteral(Result.getKind()))
1063     return;
1064 
1065   StringRef Comment =
1066       StringRef(Result.getLiteralData(), Result.getLength()).trim('"');
1067 
1068   if ((Comment.trim().size() == 0 && Comment.size() > 0) || // Is Whitespace
1069       Comment.empty()) {
1070     reportEmptyContextError(ME);
1071   }
1072 }
1073 
1074 void EmptyLocalizationContextChecker::MethodCrawler::reportEmptyContextError(
1075     const ObjCMessageExpr *ME) const {
1076   // Generate the bug report.
1077   BR.EmitBasicReport(MD, Checker, "Context Missing",
1078                      "Localizability Issue (Apple)",
1079                      "Localized string macro should include a non-empty "
1080                      "comment for translators",
1081                      PathDiagnosticLocation(ME, BR.getSourceManager(), DCtx));
1082 }
1083 
1084 namespace {
1085 class PluralMisuseChecker : public Checker<check::ASTCodeBody> {
1086 
1087   // A helper class, which walks the AST
1088   class MethodCrawler : public RecursiveASTVisitor<MethodCrawler> {
1089     BugReporter &BR;
1090     const CheckerBase *Checker;
1091     AnalysisDeclContext *AC;
1092 
1093     // This functions like a stack. We push on any IfStmt or
1094     // ConditionalOperator that matches the condition
1095     // and pop it off when we leave that statement
1096     llvm::SmallVector<const clang::Stmt *, 8> MatchingStatements;
1097     // This is true when we are the direct-child of a
1098     // matching statement
1099     bool InMatchingStatement = false;
1100 
1101   public:
1102     explicit MethodCrawler(BugReporter &InBR, const CheckerBase *Checker,
1103                            AnalysisDeclContext *InAC)
1104         : BR(InBR), Checker(Checker), AC(InAC) {}
1105 
1106     bool VisitIfStmt(const IfStmt *I);
1107     bool EndVisitIfStmt(IfStmt *I);
1108     bool TraverseIfStmt(IfStmt *x);
1109     bool VisitConditionalOperator(const ConditionalOperator *C);
1110     bool TraverseConditionalOperator(ConditionalOperator *C);
1111     bool VisitCallExpr(const CallExpr *CE);
1112     bool VisitObjCMessageExpr(const ObjCMessageExpr *ME);
1113 
1114   private:
1115     void reportPluralMisuseError(const Stmt *S) const;
1116     bool isCheckingPlurality(const Expr *E) const;
1117   };
1118 
1119 public:
1120   void checkASTCodeBody(const Decl *D, AnalysisManager &Mgr,
1121                         BugReporter &BR) const {
1122     MethodCrawler Visitor(BR, this, Mgr.getAnalysisDeclContext(D));
1123     Visitor.TraverseDecl(const_cast<Decl *>(D));
1124   }
1125 };
1126 } // end anonymous namespace
1127 
1128 // Checks the condition of the IfStmt and returns true if one
1129 // of the following heuristics are met:
1130 // 1) The conidtion is a variable with "singular" or "plural" in the name
1131 // 2) The condition is a binary operator with 1 or 2 on the right-hand side
1132 bool PluralMisuseChecker::MethodCrawler::isCheckingPlurality(
1133     const Expr *Condition) const {
1134   const BinaryOperator *BO = nullptr;
1135   // Accounts for when a VarDecl represents a BinaryOperator
1136   if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Condition)) {
1137     if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) {
1138       const Expr *InitExpr = VD->getInit();
1139       if (InitExpr) {
1140         if (const BinaryOperator *B =
1141                 dyn_cast<BinaryOperator>(InitExpr->IgnoreParenImpCasts())) {
1142           BO = B;
1143         }
1144       }
1145       if (VD->getName().lower().find("plural") != StringRef::npos ||
1146           VD->getName().lower().find("singular") != StringRef::npos) {
1147         return true;
1148       }
1149     }
1150   } else if (const BinaryOperator *B = dyn_cast<BinaryOperator>(Condition)) {
1151     BO = B;
1152   }
1153 
1154   if (BO == nullptr)
1155     return false;
1156 
1157   if (IntegerLiteral *IL = dyn_cast_or_null<IntegerLiteral>(
1158           BO->getRHS()->IgnoreParenImpCasts())) {
1159     llvm::APInt Value = IL->getValue();
1160     if (Value == 1 || Value == 2) {
1161       return true;
1162     }
1163   }
1164   return false;
1165 }
1166 
1167 // A CallExpr with "LOC" in its identifier that takes in a string literal
1168 // has been shown to almost always be a function that returns a localized
1169 // string. Raise a diagnostic when this is in a statement that matches
1170 // the condition.
1171 bool PluralMisuseChecker::MethodCrawler::VisitCallExpr(const CallExpr *CE) {
1172   if (InMatchingStatement) {
1173     if (const FunctionDecl *FD = CE->getDirectCallee()) {
1174       std::string NormalizedName =
1175           StringRef(FD->getNameInfo().getAsString()).lower();
1176       if (NormalizedName.find("loc") != std::string::npos) {
1177         for (const Expr *Arg : CE->arguments()) {
1178           if (isa<ObjCStringLiteral>(Arg))
1179             reportPluralMisuseError(CE);
1180         }
1181       }
1182     }
1183   }
1184   return true;
1185 }
1186 
1187 // The other case is for NSLocalizedString which also returns
1188 // a localized string. It's a macro for the ObjCMessageExpr
1189 // [NSBundle localizedStringForKey:value:table:] Raise a
1190 // diagnostic when this is in a statement that matches
1191 // the condition.
1192 bool PluralMisuseChecker::MethodCrawler::VisitObjCMessageExpr(
1193     const ObjCMessageExpr *ME) {
1194   const ObjCInterfaceDecl *OD = ME->getReceiverInterface();
1195   if (!OD)
1196     return true;
1197 
1198   const IdentifierInfo *odInfo = OD->getIdentifier();
1199 
1200   if (odInfo->isStr("NSBundle") &&
1201       ME->getSelector().getAsString() == "localizedStringForKey:value:table:") {
1202     if (InMatchingStatement) {
1203       reportPluralMisuseError(ME);
1204     }
1205   }
1206   return true;
1207 }
1208 
1209 /// Override TraverseIfStmt so we know when we are done traversing an IfStmt
1210 bool PluralMisuseChecker::MethodCrawler::TraverseIfStmt(IfStmt *I) {
1211   RecursiveASTVisitor<MethodCrawler>::TraverseIfStmt(I);
1212   return EndVisitIfStmt(I);
1213 }
1214 
1215 // EndVisit callbacks are not provided by the RecursiveASTVisitor
1216 // so we override TraverseIfStmt and make a call to EndVisitIfStmt
1217 // after traversing the IfStmt
1218 bool PluralMisuseChecker::MethodCrawler::EndVisitIfStmt(IfStmt *I) {
1219   MatchingStatements.pop_back();
1220   if (!MatchingStatements.empty()) {
1221     if (MatchingStatements.back() != nullptr) {
1222       InMatchingStatement = true;
1223       return true;
1224     }
1225   }
1226   InMatchingStatement = false;
1227   return true;
1228 }
1229 
1230 bool PluralMisuseChecker::MethodCrawler::VisitIfStmt(const IfStmt *I) {
1231   const Expr *Condition = I->getCond()->IgnoreParenImpCasts();
1232   if (isCheckingPlurality(Condition)) {
1233     MatchingStatements.push_back(I);
1234     InMatchingStatement = true;
1235   } else {
1236     MatchingStatements.push_back(nullptr);
1237     InMatchingStatement = false;
1238   }
1239 
1240   return true;
1241 }
1242 
1243 // Preliminary support for conditional operators.
1244 bool PluralMisuseChecker::MethodCrawler::TraverseConditionalOperator(
1245     ConditionalOperator *C) {
1246   RecursiveASTVisitor<MethodCrawler>::TraverseConditionalOperator(C);
1247   MatchingStatements.pop_back();
1248   if (!MatchingStatements.empty()) {
1249     if (MatchingStatements.back() != nullptr)
1250       InMatchingStatement = true;
1251     else
1252       InMatchingStatement = false;
1253   } else {
1254     InMatchingStatement = false;
1255   }
1256   return true;
1257 }
1258 
1259 bool PluralMisuseChecker::MethodCrawler::VisitConditionalOperator(
1260     const ConditionalOperator *C) {
1261   const Expr *Condition = C->getCond()->IgnoreParenImpCasts();
1262   if (isCheckingPlurality(Condition)) {
1263     MatchingStatements.push_back(C);
1264     InMatchingStatement = true;
1265   } else {
1266     MatchingStatements.push_back(nullptr);
1267     InMatchingStatement = false;
1268   }
1269   return true;
1270 }
1271 
1272 void PluralMisuseChecker::MethodCrawler::reportPluralMisuseError(
1273     const Stmt *S) const {
1274   // Generate the bug report.
1275   BR.EmitBasicReport(AC->getDecl(), Checker, "Plural Misuse",
1276                      "Localizability Issue (Apple)",
1277                      "Plural cases are not supported accross all languages. "
1278                      "Use a .stringsdict file instead",
1279                      PathDiagnosticLocation(S, BR.getSourceManager(), AC));
1280 }
1281 
1282 //===----------------------------------------------------------------------===//
1283 // Checker registration.
1284 //===----------------------------------------------------------------------===//
1285 
1286 void ento::registerNonLocalizedStringChecker(CheckerManager &mgr) {
1287   NonLocalizedStringChecker *checker =
1288       mgr.registerChecker<NonLocalizedStringChecker>();
1289   checker->IsAggressive =
1290       mgr.getAnalyzerOptions().getBooleanOption("AggressiveReport", false);
1291 }
1292 
1293 void ento::registerEmptyLocalizationContextChecker(CheckerManager &mgr) {
1294   mgr.registerChecker<EmptyLocalizationContextChecker>();
1295 }
1296 
1297 void ento::registerPluralMisuseChecker(CheckerManager &mgr) {
1298   mgr.registerChecker<PluralMisuseChecker>();
1299 }
1300