1 //=- LocalizationChecker.cpp -------------------------------------*- C++ -*-==//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 //  This file defines a set of checks for localizability including:
10 //  1) A checker that warns about uses of non-localized NSStrings passed to
11 //     UI methods expecting localized strings
12 //  2) A syntactic checker that warns against the bad practice of
13 //     not including a comment in NSLocalizedString macros.
14 //
15 //===----------------------------------------------------------------------===//
16 
17 #include "clang/AST/Attr.h"
18 #include "clang/AST/Decl.h"
19 #include "clang/AST/DeclObjC.h"
20 #include "clang/AST/RecursiveASTVisitor.h"
21 #include "clang/AST/StmtVisitor.h"
22 #include "clang/Lex/Lexer.h"
23 #include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
24 #include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
25 #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
26 #include "clang/StaticAnalyzer/Core/Checker.h"
27 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
28 #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
29 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
30 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
31 #include "llvm/ADT/STLExtras.h"
32 #include "llvm/Support/Unicode.h"
33 #include <optional>
34 
35 using namespace clang;
36 using namespace ento;
37 
38 namespace {
39 struct LocalizedState {
40 private:
41   enum Kind { NonLocalized, Localized } K;
42   LocalizedState(Kind InK) : K(InK) {}
43 
44 public:
45   bool isLocalized() const { return K == Localized; }
46   bool isNonLocalized() const { return K == NonLocalized; }
47 
48   static LocalizedState getLocalized() { return LocalizedState(Localized); }
49   static LocalizedState getNonLocalized() {
50     return LocalizedState(NonLocalized);
51   }
52 
53   // Overload the == operator
54   bool operator==(const LocalizedState &X) const { return K == X.K; }
55 
56   // LLVMs equivalent of a hash function
57   void Profile(llvm::FoldingSetNodeID &ID) const { ID.AddInteger(K); }
58 };
59 
60 class NonLocalizedStringChecker
61     : public Checker<check::PreCall, check::PostCall, check::PreObjCMessage,
62                      check::PostObjCMessage,
63                      check::PostStmt<ObjCStringLiteral>> {
64 
65   mutable std::unique_ptr<BugType> BT;
66 
67   // Methods that require a localized string
68   mutable llvm::DenseMap<const IdentifierInfo *,
69                          llvm::DenseMap<Selector, uint8_t>> UIMethods;
70   // Methods that return a localized string
71   mutable llvm::SmallSet<std::pair<const IdentifierInfo *, Selector>, 12> LSM;
72   // C Functions that return a localized string
73   mutable llvm::SmallSet<const IdentifierInfo *, 5> LSF;
74 
75   void initUIMethods(ASTContext &Ctx) const;
76   void initLocStringsMethods(ASTContext &Ctx) const;
77 
78   bool hasNonLocalizedState(SVal S, CheckerContext &C) const;
79   bool hasLocalizedState(SVal S, CheckerContext &C) const;
80   void setNonLocalizedState(SVal S, CheckerContext &C) const;
81   void setLocalizedState(SVal S, CheckerContext &C) const;
82 
83   bool isAnnotatedAsReturningLocalized(const Decl *D) const;
84   bool isAnnotatedAsTakingLocalized(const Decl *D) const;
85   void reportLocalizationError(SVal S, const CallEvent &M, CheckerContext &C,
86                                int argumentNumber = 0) const;
87 
88   int getLocalizedArgumentForSelector(const IdentifierInfo *Receiver,
89                                       Selector S) const;
90 
91 public:
92   NonLocalizedStringChecker();
93 
94   // When this parameter is set to true, the checker assumes all
95   // methods that return NSStrings are unlocalized. Thus, more false
96   // positives will be reported.
97   bool IsAggressive = false;
98 
99   void checkPreObjCMessage(const ObjCMethodCall &msg, CheckerContext &C) const;
100   void checkPostObjCMessage(const ObjCMethodCall &msg, CheckerContext &C) const;
101   void checkPostStmt(const ObjCStringLiteral *SL, CheckerContext &C) const;
102   void checkPreCall(const CallEvent &Call, CheckerContext &C) const;
103   void checkPostCall(const CallEvent &Call, CheckerContext &C) const;
104 };
105 
106 } // end anonymous namespace
107 
108 REGISTER_MAP_WITH_PROGRAMSTATE(LocalizedMemMap, const MemRegion *,
109                                LocalizedState)
110 
111 NonLocalizedStringChecker::NonLocalizedStringChecker() {
112   BT.reset(new BugType(this, "Unlocalizable string",
113                        "Localizability Issue (Apple)"));
114 }
115 
116 namespace {
117 class NonLocalizedStringBRVisitor final : public BugReporterVisitor {
118 
119   const MemRegion *NonLocalizedString;
120   bool Satisfied;
121 
122 public:
123   NonLocalizedStringBRVisitor(const MemRegion *NonLocalizedString)
124       : NonLocalizedString(NonLocalizedString), Satisfied(false) {
125     assert(NonLocalizedString);
126   }
127 
128   PathDiagnosticPieceRef VisitNode(const ExplodedNode *Succ,
129                                    BugReporterContext &BRC,
130                                    PathSensitiveBugReport &BR) override;
131 
132   void Profile(llvm::FoldingSetNodeID &ID) const override {
133     ID.Add(NonLocalizedString);
134   }
135 };
136 } // End anonymous namespace.
137 
138 #define NEW_RECEIVER(receiver)                                                 \
139   llvm::DenseMap<Selector, uint8_t> &receiver##M =                             \
140       UIMethods.insert({&Ctx.Idents.get(#receiver),                            \
141                         llvm::DenseMap<Selector, uint8_t>()})                  \
142           .first->second;
143 #define ADD_NULLARY_METHOD(receiver, method, argument)                         \
144   receiver##M.insert(                                                          \
145       {Ctx.Selectors.getNullarySelector(&Ctx.Idents.get(#method)), argument});
146 #define ADD_UNARY_METHOD(receiver, method, argument)                           \
147   receiver##M.insert(                                                          \
148       {Ctx.Selectors.getUnarySelector(&Ctx.Idents.get(#method)), argument});
149 #define ADD_METHOD(receiver, method_list, count, argument)                     \
150   receiver##M.insert({Ctx.Selectors.getSelector(count, method_list), argument});
151 
152 /// Initializes a list of methods that require a localized string
153 /// Format: {"ClassName", {{"selectorName:", LocStringArg#}, ...}, ...}
154 void NonLocalizedStringChecker::initUIMethods(ASTContext &Ctx) const {
155   if (!UIMethods.empty())
156     return;
157 
158   // UI Methods
159   NEW_RECEIVER(UISearchDisplayController)
160   ADD_UNARY_METHOD(UISearchDisplayController, setSearchResultsTitle, 0)
161 
162   NEW_RECEIVER(UITabBarItem)
163   IdentifierInfo *initWithTitleUITabBarItemTag[] = {
164       &Ctx.Idents.get("initWithTitle"), &Ctx.Idents.get("image"),
165       &Ctx.Idents.get("tag")};
166   ADD_METHOD(UITabBarItem, initWithTitleUITabBarItemTag, 3, 0)
167   IdentifierInfo *initWithTitleUITabBarItemImage[] = {
168       &Ctx.Idents.get("initWithTitle"), &Ctx.Idents.get("image"),
169       &Ctx.Idents.get("selectedImage")};
170   ADD_METHOD(UITabBarItem, initWithTitleUITabBarItemImage, 3, 0)
171 
172   NEW_RECEIVER(NSDockTile)
173   ADD_UNARY_METHOD(NSDockTile, setBadgeLabel, 0)
174 
175   NEW_RECEIVER(NSStatusItem)
176   ADD_UNARY_METHOD(NSStatusItem, setTitle, 0)
177   ADD_UNARY_METHOD(NSStatusItem, setToolTip, 0)
178 
179   NEW_RECEIVER(UITableViewRowAction)
180   IdentifierInfo *rowActionWithStyleUITableViewRowAction[] = {
181       &Ctx.Idents.get("rowActionWithStyle"), &Ctx.Idents.get("title"),
182       &Ctx.Idents.get("handler")};
183   ADD_METHOD(UITableViewRowAction, rowActionWithStyleUITableViewRowAction, 3, 1)
184   ADD_UNARY_METHOD(UITableViewRowAction, setTitle, 0)
185 
186   NEW_RECEIVER(NSBox)
187   ADD_UNARY_METHOD(NSBox, setTitle, 0)
188 
189   NEW_RECEIVER(NSButton)
190   ADD_UNARY_METHOD(NSButton, setTitle, 0)
191   ADD_UNARY_METHOD(NSButton, setAlternateTitle, 0)
192   IdentifierInfo *radioButtonWithTitleNSButton[] = {
193       &Ctx.Idents.get("radioButtonWithTitle"), &Ctx.Idents.get("target"),
194       &Ctx.Idents.get("action")};
195   ADD_METHOD(NSButton, radioButtonWithTitleNSButton, 3, 0)
196   IdentifierInfo *buttonWithTitleNSButtonImage[] = {
197       &Ctx.Idents.get("buttonWithTitle"), &Ctx.Idents.get("image"),
198       &Ctx.Idents.get("target"), &Ctx.Idents.get("action")};
199   ADD_METHOD(NSButton, buttonWithTitleNSButtonImage, 4, 0)
200   IdentifierInfo *checkboxWithTitleNSButton[] = {
201       &Ctx.Idents.get("checkboxWithTitle"), &Ctx.Idents.get("target"),
202       &Ctx.Idents.get("action")};
203   ADD_METHOD(NSButton, checkboxWithTitleNSButton, 3, 0)
204   IdentifierInfo *buttonWithTitleNSButtonTarget[] = {
205       &Ctx.Idents.get("buttonWithTitle"), &Ctx.Idents.get("target"),
206       &Ctx.Idents.get("action")};
207   ADD_METHOD(NSButton, buttonWithTitleNSButtonTarget, 3, 0)
208 
209   NEW_RECEIVER(NSSavePanel)
210   ADD_UNARY_METHOD(NSSavePanel, setPrompt, 0)
211   ADD_UNARY_METHOD(NSSavePanel, setTitle, 0)
212   ADD_UNARY_METHOD(NSSavePanel, setNameFieldLabel, 0)
213   ADD_UNARY_METHOD(NSSavePanel, setNameFieldStringValue, 0)
214   ADD_UNARY_METHOD(NSSavePanel, setMessage, 0)
215 
216   NEW_RECEIVER(UIPrintInfo)
217   ADD_UNARY_METHOD(UIPrintInfo, setJobName, 0)
218 
219   NEW_RECEIVER(NSTabViewItem)
220   ADD_UNARY_METHOD(NSTabViewItem, setLabel, 0)
221   ADD_UNARY_METHOD(NSTabViewItem, setToolTip, 0)
222 
223   NEW_RECEIVER(NSBrowser)
224   IdentifierInfo *setTitleNSBrowser[] = {&Ctx.Idents.get("setTitle"),
225                                          &Ctx.Idents.get("ofColumn")};
226   ADD_METHOD(NSBrowser, setTitleNSBrowser, 2, 0)
227 
228   NEW_RECEIVER(UIAccessibilityElement)
229   ADD_UNARY_METHOD(UIAccessibilityElement, setAccessibilityLabel, 0)
230   ADD_UNARY_METHOD(UIAccessibilityElement, setAccessibilityHint, 0)
231   ADD_UNARY_METHOD(UIAccessibilityElement, setAccessibilityValue, 0)
232 
233   NEW_RECEIVER(UIAlertAction)
234   IdentifierInfo *actionWithTitleUIAlertAction[] = {
235       &Ctx.Idents.get("actionWithTitle"), &Ctx.Idents.get("style"),
236       &Ctx.Idents.get("handler")};
237   ADD_METHOD(UIAlertAction, actionWithTitleUIAlertAction, 3, 0)
238 
239   NEW_RECEIVER(NSPopUpButton)
240   ADD_UNARY_METHOD(NSPopUpButton, addItemWithTitle, 0)
241   IdentifierInfo *insertItemWithTitleNSPopUpButton[] = {
242       &Ctx.Idents.get("insertItemWithTitle"), &Ctx.Idents.get("atIndex")};
243   ADD_METHOD(NSPopUpButton, insertItemWithTitleNSPopUpButton, 2, 0)
244   ADD_UNARY_METHOD(NSPopUpButton, removeItemWithTitle, 0)
245   ADD_UNARY_METHOD(NSPopUpButton, selectItemWithTitle, 0)
246   ADD_UNARY_METHOD(NSPopUpButton, setTitle, 0)
247 
248   NEW_RECEIVER(NSTableViewRowAction)
249   IdentifierInfo *rowActionWithStyleNSTableViewRowAction[] = {
250       &Ctx.Idents.get("rowActionWithStyle"), &Ctx.Idents.get("title"),
251       &Ctx.Idents.get("handler")};
252   ADD_METHOD(NSTableViewRowAction, rowActionWithStyleNSTableViewRowAction, 3, 1)
253   ADD_UNARY_METHOD(NSTableViewRowAction, setTitle, 0)
254 
255   NEW_RECEIVER(NSImage)
256   ADD_UNARY_METHOD(NSImage, setAccessibilityDescription, 0)
257 
258   NEW_RECEIVER(NSUserActivity)
259   ADD_UNARY_METHOD(NSUserActivity, setTitle, 0)
260 
261   NEW_RECEIVER(NSPathControlItem)
262   ADD_UNARY_METHOD(NSPathControlItem, setTitle, 0)
263 
264   NEW_RECEIVER(NSCell)
265   ADD_UNARY_METHOD(NSCell, initTextCell, 0)
266   ADD_UNARY_METHOD(NSCell, setTitle, 0)
267   ADD_UNARY_METHOD(NSCell, setStringValue, 0)
268 
269   NEW_RECEIVER(NSPathControl)
270   ADD_UNARY_METHOD(NSPathControl, setPlaceholderString, 0)
271 
272   NEW_RECEIVER(UIAccessibility)
273   ADD_UNARY_METHOD(UIAccessibility, setAccessibilityLabel, 0)
274   ADD_UNARY_METHOD(UIAccessibility, setAccessibilityHint, 0)
275   ADD_UNARY_METHOD(UIAccessibility, setAccessibilityValue, 0)
276 
277   NEW_RECEIVER(NSTableColumn)
278   ADD_UNARY_METHOD(NSTableColumn, setTitle, 0)
279   ADD_UNARY_METHOD(NSTableColumn, setHeaderToolTip, 0)
280 
281   NEW_RECEIVER(NSSegmentedControl)
282   IdentifierInfo *setLabelNSSegmentedControl[] = {
283       &Ctx.Idents.get("setLabel"), &Ctx.Idents.get("forSegment")};
284   ADD_METHOD(NSSegmentedControl, setLabelNSSegmentedControl, 2, 0)
285   IdentifierInfo *setToolTipNSSegmentedControl[] = {
286       &Ctx.Idents.get("setToolTip"), &Ctx.Idents.get("forSegment")};
287   ADD_METHOD(NSSegmentedControl, setToolTipNSSegmentedControl, 2, 0)
288 
289   NEW_RECEIVER(NSButtonCell)
290   ADD_UNARY_METHOD(NSButtonCell, setTitle, 0)
291   ADD_UNARY_METHOD(NSButtonCell, setAlternateTitle, 0)
292 
293   NEW_RECEIVER(NSDatePickerCell)
294   ADD_UNARY_METHOD(NSDatePickerCell, initTextCell, 0)
295 
296   NEW_RECEIVER(NSSliderCell)
297   ADD_UNARY_METHOD(NSSliderCell, setTitle, 0)
298 
299   NEW_RECEIVER(NSControl)
300   ADD_UNARY_METHOD(NSControl, setStringValue, 0)
301 
302   NEW_RECEIVER(NSAccessibility)
303   ADD_UNARY_METHOD(NSAccessibility, setAccessibilityValueDescription, 0)
304   ADD_UNARY_METHOD(NSAccessibility, setAccessibilityLabel, 0)
305   ADD_UNARY_METHOD(NSAccessibility, setAccessibilityTitle, 0)
306   ADD_UNARY_METHOD(NSAccessibility, setAccessibilityPlaceholderValue, 0)
307   ADD_UNARY_METHOD(NSAccessibility, setAccessibilityHelp, 0)
308 
309   NEW_RECEIVER(NSMatrix)
310   IdentifierInfo *setToolTipNSMatrix[] = {&Ctx.Idents.get("setToolTip"),
311                                           &Ctx.Idents.get("forCell")};
312   ADD_METHOD(NSMatrix, setToolTipNSMatrix, 2, 0)
313 
314   NEW_RECEIVER(NSPrintPanel)
315   ADD_UNARY_METHOD(NSPrintPanel, setDefaultButtonTitle, 0)
316 
317   NEW_RECEIVER(UILocalNotification)
318   ADD_UNARY_METHOD(UILocalNotification, setAlertBody, 0)
319   ADD_UNARY_METHOD(UILocalNotification, setAlertAction, 0)
320   ADD_UNARY_METHOD(UILocalNotification, setAlertTitle, 0)
321 
322   NEW_RECEIVER(NSSlider)
323   ADD_UNARY_METHOD(NSSlider, setTitle, 0)
324 
325   NEW_RECEIVER(UIMenuItem)
326   IdentifierInfo *initWithTitleUIMenuItem[] = {&Ctx.Idents.get("initWithTitle"),
327                                                &Ctx.Idents.get("action")};
328   ADD_METHOD(UIMenuItem, initWithTitleUIMenuItem, 2, 0)
329   ADD_UNARY_METHOD(UIMenuItem, setTitle, 0)
330 
331   NEW_RECEIVER(UIAlertController)
332   IdentifierInfo *alertControllerWithTitleUIAlertController[] = {
333       &Ctx.Idents.get("alertControllerWithTitle"), &Ctx.Idents.get("message"),
334       &Ctx.Idents.get("preferredStyle")};
335   ADD_METHOD(UIAlertController, alertControllerWithTitleUIAlertController, 3, 1)
336   ADD_UNARY_METHOD(UIAlertController, setTitle, 0)
337   ADD_UNARY_METHOD(UIAlertController, setMessage, 0)
338 
339   NEW_RECEIVER(UIApplicationShortcutItem)
340   IdentifierInfo *initWithTypeUIApplicationShortcutItemIcon[] = {
341       &Ctx.Idents.get("initWithType"), &Ctx.Idents.get("localizedTitle"),
342       &Ctx.Idents.get("localizedSubtitle"), &Ctx.Idents.get("icon"),
343       &Ctx.Idents.get("userInfo")};
344   ADD_METHOD(UIApplicationShortcutItem,
345              initWithTypeUIApplicationShortcutItemIcon, 5, 1)
346   IdentifierInfo *initWithTypeUIApplicationShortcutItem[] = {
347       &Ctx.Idents.get("initWithType"), &Ctx.Idents.get("localizedTitle")};
348   ADD_METHOD(UIApplicationShortcutItem, initWithTypeUIApplicationShortcutItem,
349              2, 1)
350 
351   NEW_RECEIVER(UIActionSheet)
352   IdentifierInfo *initWithTitleUIActionSheet[] = {
353       &Ctx.Idents.get("initWithTitle"), &Ctx.Idents.get("delegate"),
354       &Ctx.Idents.get("cancelButtonTitle"),
355       &Ctx.Idents.get("destructiveButtonTitle"),
356       &Ctx.Idents.get("otherButtonTitles")};
357   ADD_METHOD(UIActionSheet, initWithTitleUIActionSheet, 5, 0)
358   ADD_UNARY_METHOD(UIActionSheet, addButtonWithTitle, 0)
359   ADD_UNARY_METHOD(UIActionSheet, setTitle, 0)
360 
361   NEW_RECEIVER(UIAccessibilityCustomAction)
362   IdentifierInfo *initWithNameUIAccessibilityCustomAction[] = {
363       &Ctx.Idents.get("initWithName"), &Ctx.Idents.get("target"),
364       &Ctx.Idents.get("selector")};
365   ADD_METHOD(UIAccessibilityCustomAction,
366              initWithNameUIAccessibilityCustomAction, 3, 0)
367   ADD_UNARY_METHOD(UIAccessibilityCustomAction, setName, 0)
368 
369   NEW_RECEIVER(UISearchBar)
370   ADD_UNARY_METHOD(UISearchBar, setText, 0)
371   ADD_UNARY_METHOD(UISearchBar, setPrompt, 0)
372   ADD_UNARY_METHOD(UISearchBar, setPlaceholder, 0)
373 
374   NEW_RECEIVER(UIBarItem)
375   ADD_UNARY_METHOD(UIBarItem, setTitle, 0)
376 
377   NEW_RECEIVER(UITextView)
378   ADD_UNARY_METHOD(UITextView, setText, 0)
379 
380   NEW_RECEIVER(NSView)
381   ADD_UNARY_METHOD(NSView, setToolTip, 0)
382 
383   NEW_RECEIVER(NSTextField)
384   ADD_UNARY_METHOD(NSTextField, setPlaceholderString, 0)
385   ADD_UNARY_METHOD(NSTextField, textFieldWithString, 0)
386   ADD_UNARY_METHOD(NSTextField, wrappingLabelWithString, 0)
387   ADD_UNARY_METHOD(NSTextField, labelWithString, 0)
388 
389   NEW_RECEIVER(NSAttributedString)
390   ADD_UNARY_METHOD(NSAttributedString, initWithString, 0)
391   IdentifierInfo *initWithStringNSAttributedString[] = {
392       &Ctx.Idents.get("initWithString"), &Ctx.Idents.get("attributes")};
393   ADD_METHOD(NSAttributedString, initWithStringNSAttributedString, 2, 0)
394 
395   NEW_RECEIVER(NSText)
396   ADD_UNARY_METHOD(NSText, setString, 0)
397 
398   NEW_RECEIVER(UIKeyCommand)
399   IdentifierInfo *keyCommandWithInputUIKeyCommand[] = {
400       &Ctx.Idents.get("keyCommandWithInput"), &Ctx.Idents.get("modifierFlags"),
401       &Ctx.Idents.get("action"), &Ctx.Idents.get("discoverabilityTitle")};
402   ADD_METHOD(UIKeyCommand, keyCommandWithInputUIKeyCommand, 4, 3)
403   ADD_UNARY_METHOD(UIKeyCommand, setDiscoverabilityTitle, 0)
404 
405   NEW_RECEIVER(UILabel)
406   ADD_UNARY_METHOD(UILabel, setText, 0)
407 
408   NEW_RECEIVER(NSAlert)
409   IdentifierInfo *alertWithMessageTextNSAlert[] = {
410       &Ctx.Idents.get("alertWithMessageText"), &Ctx.Idents.get("defaultButton"),
411       &Ctx.Idents.get("alternateButton"), &Ctx.Idents.get("otherButton"),
412       &Ctx.Idents.get("informativeTextWithFormat")};
413   ADD_METHOD(NSAlert, alertWithMessageTextNSAlert, 5, 0)
414   ADD_UNARY_METHOD(NSAlert, addButtonWithTitle, 0)
415   ADD_UNARY_METHOD(NSAlert, setMessageText, 0)
416   ADD_UNARY_METHOD(NSAlert, setInformativeText, 0)
417   ADD_UNARY_METHOD(NSAlert, setHelpAnchor, 0)
418 
419   NEW_RECEIVER(UIMutableApplicationShortcutItem)
420   ADD_UNARY_METHOD(UIMutableApplicationShortcutItem, setLocalizedTitle, 0)
421   ADD_UNARY_METHOD(UIMutableApplicationShortcutItem, setLocalizedSubtitle, 0)
422 
423   NEW_RECEIVER(UIButton)
424   IdentifierInfo *setTitleUIButton[] = {&Ctx.Idents.get("setTitle"),
425                                         &Ctx.Idents.get("forState")};
426   ADD_METHOD(UIButton, setTitleUIButton, 2, 0)
427 
428   NEW_RECEIVER(NSWindow)
429   ADD_UNARY_METHOD(NSWindow, setTitle, 0)
430   IdentifierInfo *minFrameWidthWithTitleNSWindow[] = {
431       &Ctx.Idents.get("minFrameWidthWithTitle"), &Ctx.Idents.get("styleMask")};
432   ADD_METHOD(NSWindow, minFrameWidthWithTitleNSWindow, 2, 0)
433   ADD_UNARY_METHOD(NSWindow, setMiniwindowTitle, 0)
434 
435   NEW_RECEIVER(NSPathCell)
436   ADD_UNARY_METHOD(NSPathCell, setPlaceholderString, 0)
437 
438   NEW_RECEIVER(UIDocumentMenuViewController)
439   IdentifierInfo *addOptionWithTitleUIDocumentMenuViewController[] = {
440       &Ctx.Idents.get("addOptionWithTitle"), &Ctx.Idents.get("image"),
441       &Ctx.Idents.get("order"), &Ctx.Idents.get("handler")};
442   ADD_METHOD(UIDocumentMenuViewController,
443              addOptionWithTitleUIDocumentMenuViewController, 4, 0)
444 
445   NEW_RECEIVER(UINavigationItem)
446   ADD_UNARY_METHOD(UINavigationItem, initWithTitle, 0)
447   ADD_UNARY_METHOD(UINavigationItem, setTitle, 0)
448   ADD_UNARY_METHOD(UINavigationItem, setPrompt, 0)
449 
450   NEW_RECEIVER(UIAlertView)
451   IdentifierInfo *initWithTitleUIAlertView[] = {
452       &Ctx.Idents.get("initWithTitle"), &Ctx.Idents.get("message"),
453       &Ctx.Idents.get("delegate"), &Ctx.Idents.get("cancelButtonTitle"),
454       &Ctx.Idents.get("otherButtonTitles")};
455   ADD_METHOD(UIAlertView, initWithTitleUIAlertView, 5, 0)
456   ADD_UNARY_METHOD(UIAlertView, addButtonWithTitle, 0)
457   ADD_UNARY_METHOD(UIAlertView, setTitle, 0)
458   ADD_UNARY_METHOD(UIAlertView, setMessage, 0)
459 
460   NEW_RECEIVER(NSFormCell)
461   ADD_UNARY_METHOD(NSFormCell, initTextCell, 0)
462   ADD_UNARY_METHOD(NSFormCell, setTitle, 0)
463   ADD_UNARY_METHOD(NSFormCell, setPlaceholderString, 0)
464 
465   NEW_RECEIVER(NSUserNotification)
466   ADD_UNARY_METHOD(NSUserNotification, setTitle, 0)
467   ADD_UNARY_METHOD(NSUserNotification, setSubtitle, 0)
468   ADD_UNARY_METHOD(NSUserNotification, setInformativeText, 0)
469   ADD_UNARY_METHOD(NSUserNotification, setActionButtonTitle, 0)
470   ADD_UNARY_METHOD(NSUserNotification, setOtherButtonTitle, 0)
471   ADD_UNARY_METHOD(NSUserNotification, setResponsePlaceholder, 0)
472 
473   NEW_RECEIVER(NSToolbarItem)
474   ADD_UNARY_METHOD(NSToolbarItem, setLabel, 0)
475   ADD_UNARY_METHOD(NSToolbarItem, setPaletteLabel, 0)
476   ADD_UNARY_METHOD(NSToolbarItem, setToolTip, 0)
477 
478   NEW_RECEIVER(NSProgress)
479   ADD_UNARY_METHOD(NSProgress, setLocalizedDescription, 0)
480   ADD_UNARY_METHOD(NSProgress, setLocalizedAdditionalDescription, 0)
481 
482   NEW_RECEIVER(NSSegmentedCell)
483   IdentifierInfo *setLabelNSSegmentedCell[] = {&Ctx.Idents.get("setLabel"),
484                                                &Ctx.Idents.get("forSegment")};
485   ADD_METHOD(NSSegmentedCell, setLabelNSSegmentedCell, 2, 0)
486   IdentifierInfo *setToolTipNSSegmentedCell[] = {&Ctx.Idents.get("setToolTip"),
487                                                  &Ctx.Idents.get("forSegment")};
488   ADD_METHOD(NSSegmentedCell, setToolTipNSSegmentedCell, 2, 0)
489 
490   NEW_RECEIVER(NSUndoManager)
491   ADD_UNARY_METHOD(NSUndoManager, setActionName, 0)
492   ADD_UNARY_METHOD(NSUndoManager, undoMenuTitleForUndoActionName, 0)
493   ADD_UNARY_METHOD(NSUndoManager, redoMenuTitleForUndoActionName, 0)
494 
495   NEW_RECEIVER(NSMenuItem)
496   IdentifierInfo *initWithTitleNSMenuItem[] = {
497       &Ctx.Idents.get("initWithTitle"), &Ctx.Idents.get("action"),
498       &Ctx.Idents.get("keyEquivalent")};
499   ADD_METHOD(NSMenuItem, initWithTitleNSMenuItem, 3, 0)
500   ADD_UNARY_METHOD(NSMenuItem, setTitle, 0)
501   ADD_UNARY_METHOD(NSMenuItem, setToolTip, 0)
502 
503   NEW_RECEIVER(NSPopUpButtonCell)
504   IdentifierInfo *initTextCellNSPopUpButtonCell[] = {
505       &Ctx.Idents.get("initTextCell"), &Ctx.Idents.get("pullsDown")};
506   ADD_METHOD(NSPopUpButtonCell, initTextCellNSPopUpButtonCell, 2, 0)
507   ADD_UNARY_METHOD(NSPopUpButtonCell, addItemWithTitle, 0)
508   IdentifierInfo *insertItemWithTitleNSPopUpButtonCell[] = {
509       &Ctx.Idents.get("insertItemWithTitle"), &Ctx.Idents.get("atIndex")};
510   ADD_METHOD(NSPopUpButtonCell, insertItemWithTitleNSPopUpButtonCell, 2, 0)
511   ADD_UNARY_METHOD(NSPopUpButtonCell, removeItemWithTitle, 0)
512   ADD_UNARY_METHOD(NSPopUpButtonCell, selectItemWithTitle, 0)
513   ADD_UNARY_METHOD(NSPopUpButtonCell, setTitle, 0)
514 
515   NEW_RECEIVER(NSViewController)
516   ADD_UNARY_METHOD(NSViewController, setTitle, 0)
517 
518   NEW_RECEIVER(NSMenu)
519   ADD_UNARY_METHOD(NSMenu, initWithTitle, 0)
520   IdentifierInfo *insertItemWithTitleNSMenu[] = {
521       &Ctx.Idents.get("insertItemWithTitle"), &Ctx.Idents.get("action"),
522       &Ctx.Idents.get("keyEquivalent"), &Ctx.Idents.get("atIndex")};
523   ADD_METHOD(NSMenu, insertItemWithTitleNSMenu, 4, 0)
524   IdentifierInfo *addItemWithTitleNSMenu[] = {
525       &Ctx.Idents.get("addItemWithTitle"), &Ctx.Idents.get("action"),
526       &Ctx.Idents.get("keyEquivalent")};
527   ADD_METHOD(NSMenu, addItemWithTitleNSMenu, 3, 0)
528   ADD_UNARY_METHOD(NSMenu, setTitle, 0)
529 
530   NEW_RECEIVER(UIMutableUserNotificationAction)
531   ADD_UNARY_METHOD(UIMutableUserNotificationAction, setTitle, 0)
532 
533   NEW_RECEIVER(NSForm)
534   ADD_UNARY_METHOD(NSForm, addEntry, 0)
535   IdentifierInfo *insertEntryNSForm[] = {&Ctx.Idents.get("insertEntry"),
536                                          &Ctx.Idents.get("atIndex")};
537   ADD_METHOD(NSForm, insertEntryNSForm, 2, 0)
538 
539   NEW_RECEIVER(NSTextFieldCell)
540   ADD_UNARY_METHOD(NSTextFieldCell, setPlaceholderString, 0)
541 
542   NEW_RECEIVER(NSUserNotificationAction)
543   IdentifierInfo *actionWithIdentifierNSUserNotificationAction[] = {
544       &Ctx.Idents.get("actionWithIdentifier"), &Ctx.Idents.get("title")};
545   ADD_METHOD(NSUserNotificationAction,
546              actionWithIdentifierNSUserNotificationAction, 2, 1)
547 
548   NEW_RECEIVER(UITextField)
549   ADD_UNARY_METHOD(UITextField, setText, 0)
550   ADD_UNARY_METHOD(UITextField, setPlaceholder, 0)
551 
552   NEW_RECEIVER(UIBarButtonItem)
553   IdentifierInfo *initWithTitleUIBarButtonItem[] = {
554       &Ctx.Idents.get("initWithTitle"), &Ctx.Idents.get("style"),
555       &Ctx.Idents.get("target"), &Ctx.Idents.get("action")};
556   ADD_METHOD(UIBarButtonItem, initWithTitleUIBarButtonItem, 4, 0)
557 
558   NEW_RECEIVER(UIViewController)
559   ADD_UNARY_METHOD(UIViewController, setTitle, 0)
560 
561   NEW_RECEIVER(UISegmentedControl)
562   IdentifierInfo *insertSegmentWithTitleUISegmentedControl[] = {
563       &Ctx.Idents.get("insertSegmentWithTitle"), &Ctx.Idents.get("atIndex"),
564       &Ctx.Idents.get("animated")};
565   ADD_METHOD(UISegmentedControl, insertSegmentWithTitleUISegmentedControl, 3, 0)
566   IdentifierInfo *setTitleUISegmentedControl[] = {
567       &Ctx.Idents.get("setTitle"), &Ctx.Idents.get("forSegmentAtIndex")};
568   ADD_METHOD(UISegmentedControl, setTitleUISegmentedControl, 2, 0)
569 
570   NEW_RECEIVER(NSAccessibilityCustomRotorItemResult)
571   IdentifierInfo
572       *initWithItemLoadingTokenNSAccessibilityCustomRotorItemResult[] = {
573           &Ctx.Idents.get("initWithItemLoadingToken"),
574           &Ctx.Idents.get("customLabel")};
575   ADD_METHOD(NSAccessibilityCustomRotorItemResult,
576              initWithItemLoadingTokenNSAccessibilityCustomRotorItemResult, 2, 1)
577   ADD_UNARY_METHOD(NSAccessibilityCustomRotorItemResult, setCustomLabel, 0)
578 
579   NEW_RECEIVER(UIContextualAction)
580   IdentifierInfo *contextualActionWithStyleUIContextualAction[] = {
581       &Ctx.Idents.get("contextualActionWithStyle"), &Ctx.Idents.get("title"),
582       &Ctx.Idents.get("handler")};
583   ADD_METHOD(UIContextualAction, contextualActionWithStyleUIContextualAction, 3,
584              1)
585   ADD_UNARY_METHOD(UIContextualAction, setTitle, 0)
586 
587   NEW_RECEIVER(NSAccessibilityCustomRotor)
588   IdentifierInfo *initWithLabelNSAccessibilityCustomRotor[] = {
589       &Ctx.Idents.get("initWithLabel"), &Ctx.Idents.get("itemSearchDelegate")};
590   ADD_METHOD(NSAccessibilityCustomRotor,
591              initWithLabelNSAccessibilityCustomRotor, 2, 0)
592   ADD_UNARY_METHOD(NSAccessibilityCustomRotor, setLabel, 0)
593 
594   NEW_RECEIVER(NSWindowTab)
595   ADD_UNARY_METHOD(NSWindowTab, setTitle, 0)
596   ADD_UNARY_METHOD(NSWindowTab, setToolTip, 0)
597 
598   NEW_RECEIVER(NSAccessibilityCustomAction)
599   IdentifierInfo *initWithNameNSAccessibilityCustomAction[] = {
600       &Ctx.Idents.get("initWithName"), &Ctx.Idents.get("handler")};
601   ADD_METHOD(NSAccessibilityCustomAction,
602              initWithNameNSAccessibilityCustomAction, 2, 0)
603   IdentifierInfo *initWithNameTargetNSAccessibilityCustomAction[] = {
604       &Ctx.Idents.get("initWithName"), &Ctx.Idents.get("target"),
605       &Ctx.Idents.get("selector")};
606   ADD_METHOD(NSAccessibilityCustomAction,
607              initWithNameTargetNSAccessibilityCustomAction, 3, 0)
608   ADD_UNARY_METHOD(NSAccessibilityCustomAction, setName, 0)
609 }
610 
611 #define LSF_INSERT(function_name) LSF.insert(&Ctx.Idents.get(function_name));
612 #define LSM_INSERT_NULLARY(receiver, method_name)                              \
613   LSM.insert({&Ctx.Idents.get(receiver), Ctx.Selectors.getNullarySelector(     \
614                                              &Ctx.Idents.get(method_name))});
615 #define LSM_INSERT_UNARY(receiver, method_name)                                \
616   LSM.insert({&Ctx.Idents.get(receiver),                                       \
617               Ctx.Selectors.getUnarySelector(&Ctx.Idents.get(method_name))});
618 #define LSM_INSERT_SELECTOR(receiver, method_list, arguments)                  \
619   LSM.insert({&Ctx.Idents.get(receiver),                                       \
620               Ctx.Selectors.getSelector(arguments, method_list)});
621 
622 /// Initializes a list of methods and C functions that return a localized string
623 void NonLocalizedStringChecker::initLocStringsMethods(ASTContext &Ctx) const {
624   if (!LSM.empty())
625     return;
626 
627   IdentifierInfo *LocalizedStringMacro[] = {
628       &Ctx.Idents.get("localizedStringForKey"), &Ctx.Idents.get("value"),
629       &Ctx.Idents.get("table")};
630   LSM_INSERT_SELECTOR("NSBundle", LocalizedStringMacro, 3)
631   LSM_INSERT_UNARY("NSDateFormatter", "stringFromDate")
632   IdentifierInfo *LocalizedStringFromDate[] = {
633       &Ctx.Idents.get("localizedStringFromDate"), &Ctx.Idents.get("dateStyle"),
634       &Ctx.Idents.get("timeStyle")};
635   LSM_INSERT_SELECTOR("NSDateFormatter", LocalizedStringFromDate, 3)
636   LSM_INSERT_UNARY("NSNumberFormatter", "stringFromNumber")
637   LSM_INSERT_NULLARY("UITextField", "text")
638   LSM_INSERT_NULLARY("UITextView", "text")
639   LSM_INSERT_NULLARY("UILabel", "text")
640 
641   LSF_INSERT("CFDateFormatterCreateStringWithDate");
642   LSF_INSERT("CFDateFormatterCreateStringWithAbsoluteTime");
643   LSF_INSERT("CFNumberFormatterCreateStringWithNumber");
644 }
645 
646 /// Checks to see if the method / function declaration includes
647 /// __attribute__((annotate("returns_localized_nsstring")))
648 bool NonLocalizedStringChecker::isAnnotatedAsReturningLocalized(
649     const Decl *D) const {
650   if (!D)
651     return false;
652   return std::any_of(
653       D->specific_attr_begin<AnnotateAttr>(),
654       D->specific_attr_end<AnnotateAttr>(), [](const AnnotateAttr *Ann) {
655         return Ann->getAnnotation() == "returns_localized_nsstring";
656       });
657 }
658 
659 /// Checks to see if the method / function declaration includes
660 /// __attribute__((annotate("takes_localized_nsstring")))
661 bool NonLocalizedStringChecker::isAnnotatedAsTakingLocalized(
662     const Decl *D) const {
663   if (!D)
664     return false;
665   return std::any_of(
666       D->specific_attr_begin<AnnotateAttr>(),
667       D->specific_attr_end<AnnotateAttr>(), [](const AnnotateAttr *Ann) {
668         return Ann->getAnnotation() == "takes_localized_nsstring";
669       });
670 }
671 
672 /// Returns true if the given SVal is marked as Localized in the program state
673 bool NonLocalizedStringChecker::hasLocalizedState(SVal S,
674                                                   CheckerContext &C) const {
675   const MemRegion *mt = S.getAsRegion();
676   if (mt) {
677     const LocalizedState *LS = C.getState()->get<LocalizedMemMap>(mt);
678     if (LS && LS->isLocalized())
679       return true;
680   }
681   return false;
682 }
683 
684 /// Returns true if the given SVal is marked as NonLocalized in the program
685 /// state
686 bool NonLocalizedStringChecker::hasNonLocalizedState(SVal S,
687                                                      CheckerContext &C) const {
688   const MemRegion *mt = S.getAsRegion();
689   if (mt) {
690     const LocalizedState *LS = C.getState()->get<LocalizedMemMap>(mt);
691     if (LS && LS->isNonLocalized())
692       return true;
693   }
694   return false;
695 }
696 
697 /// Marks the given SVal as Localized in the program state
698 void NonLocalizedStringChecker::setLocalizedState(const SVal S,
699                                                   CheckerContext &C) const {
700   const MemRegion *mt = S.getAsRegion();
701   if (mt) {
702     ProgramStateRef State =
703         C.getState()->set<LocalizedMemMap>(mt, LocalizedState::getLocalized());
704     C.addTransition(State);
705   }
706 }
707 
708 /// Marks the given SVal as NonLocalized in the program state
709 void NonLocalizedStringChecker::setNonLocalizedState(const SVal S,
710                                                      CheckerContext &C) const {
711   const MemRegion *mt = S.getAsRegion();
712   if (mt) {
713     ProgramStateRef State = C.getState()->set<LocalizedMemMap>(
714         mt, LocalizedState::getNonLocalized());
715     C.addTransition(State);
716   }
717 }
718 
719 
720 static bool isDebuggingName(std::string name) {
721   return StringRef(name).lower().find("debug") != StringRef::npos;
722 }
723 
724 /// Returns true when, heuristically, the analyzer may be analyzing debugging
725 /// code. We use this to suppress localization diagnostics in un-localized user
726 /// interfaces that are only used for debugging and are therefore not user
727 /// facing.
728 static bool isDebuggingContext(CheckerContext &C) {
729   const Decl *D = C.getCurrentAnalysisDeclContext()->getDecl();
730   if (!D)
731     return false;
732 
733   if (auto *ND = dyn_cast<NamedDecl>(D)) {
734     if (isDebuggingName(ND->getNameAsString()))
735       return true;
736   }
737 
738   const DeclContext *DC = D->getDeclContext();
739 
740   if (auto *CD = dyn_cast<ObjCContainerDecl>(DC)) {
741     if (isDebuggingName(CD->getNameAsString()))
742       return true;
743   }
744 
745   return false;
746 }
747 
748 
749 /// Reports a localization error for the passed in method call and SVal
750 void NonLocalizedStringChecker::reportLocalizationError(
751     SVal S, const CallEvent &M, CheckerContext &C, int argumentNumber) const {
752 
753   // Don't warn about localization errors in classes and methods that
754   // may be debug code.
755   if (isDebuggingContext(C))
756     return;
757 
758   static CheckerProgramPointTag Tag("NonLocalizedStringChecker",
759                                     "UnlocalizedString");
760   ExplodedNode *ErrNode = C.addTransition(C.getState(), C.getPredecessor(), &Tag);
761 
762   if (!ErrNode)
763     return;
764 
765   // Generate the bug report.
766   auto R = std::make_unique<PathSensitiveBugReport>(
767       *BT, "User-facing text should use localized string macro", ErrNode);
768   if (argumentNumber) {
769     R->addRange(M.getArgExpr(argumentNumber - 1)->getSourceRange());
770   } else {
771     R->addRange(M.getSourceRange());
772   }
773   R->markInteresting(S);
774 
775   const MemRegion *StringRegion = S.getAsRegion();
776   if (StringRegion)
777     R->addVisitor(std::make_unique<NonLocalizedStringBRVisitor>(StringRegion));
778 
779   C.emitReport(std::move(R));
780 }
781 
782 /// Returns the argument number requiring localized string if it exists
783 /// otherwise, returns -1
784 int NonLocalizedStringChecker::getLocalizedArgumentForSelector(
785     const IdentifierInfo *Receiver, Selector S) const {
786   auto method = UIMethods.find(Receiver);
787 
788   if (method == UIMethods.end())
789     return -1;
790 
791   auto argumentIterator = method->getSecond().find(S);
792 
793   if (argumentIterator == method->getSecond().end())
794     return -1;
795 
796   int argumentNumber = argumentIterator->getSecond();
797   return argumentNumber;
798 }
799 
800 /// Check if the string being passed in has NonLocalized state
801 void NonLocalizedStringChecker::checkPreObjCMessage(const ObjCMethodCall &msg,
802                                                     CheckerContext &C) const {
803   initUIMethods(C.getASTContext());
804 
805   const ObjCInterfaceDecl *OD = msg.getReceiverInterface();
806   if (!OD)
807     return;
808   const IdentifierInfo *odInfo = OD->getIdentifier();
809 
810   Selector S = msg.getSelector();
811 
812   std::string SelectorString = S.getAsString();
813   StringRef SelectorName = SelectorString;
814   assert(!SelectorName.empty());
815 
816   if (odInfo->isStr("NSString")) {
817     // Handle the case where the receiver is an NSString
818     // These special NSString methods draw to the screen
819 
820     if (!(SelectorName.startswith("drawAtPoint") ||
821           SelectorName.startswith("drawInRect") ||
822           SelectorName.startswith("drawWithRect")))
823       return;
824 
825     SVal svTitle = msg.getReceiverSVal();
826 
827     bool isNonLocalized = hasNonLocalizedState(svTitle, C);
828 
829     if (isNonLocalized) {
830       reportLocalizationError(svTitle, msg, C);
831     }
832   }
833 
834   int argumentNumber = getLocalizedArgumentForSelector(odInfo, S);
835   // Go up each hierarchy of superclasses and their protocols
836   while (argumentNumber < 0 && OD->getSuperClass() != nullptr) {
837     for (const auto *P : OD->all_referenced_protocols()) {
838       argumentNumber = getLocalizedArgumentForSelector(P->getIdentifier(), S);
839       if (argumentNumber >= 0)
840         break;
841     }
842     if (argumentNumber < 0) {
843       OD = OD->getSuperClass();
844       argumentNumber = getLocalizedArgumentForSelector(OD->getIdentifier(), S);
845     }
846   }
847 
848   if (argumentNumber < 0) { // There was no match in UIMethods
849     if (const Decl *D = msg.getDecl()) {
850       if (const ObjCMethodDecl *OMD = dyn_cast_or_null<ObjCMethodDecl>(D)) {
851         for (auto [Idx, FormalParam] : llvm::enumerate(OMD->parameters())) {
852           if (isAnnotatedAsTakingLocalized(FormalParam)) {
853             argumentNumber = Idx;
854             break;
855           }
856         }
857       }
858     }
859   }
860 
861   if (argumentNumber < 0) // Still no match
862     return;
863 
864   SVal svTitle = msg.getArgSVal(argumentNumber);
865 
866   if (const ObjCStringRegion *SR =
867           dyn_cast_or_null<ObjCStringRegion>(svTitle.getAsRegion())) {
868     StringRef stringValue =
869         SR->getObjCStringLiteral()->getString()->getString();
870     if ((stringValue.trim().size() == 0 && stringValue.size() > 0) ||
871         stringValue.empty())
872       return;
873     if (!IsAggressive && llvm::sys::unicode::columnWidthUTF8(stringValue) < 2)
874       return;
875   }
876 
877   bool isNonLocalized = hasNonLocalizedState(svTitle, C);
878 
879   if (isNonLocalized) {
880     reportLocalizationError(svTitle, msg, C, argumentNumber + 1);
881   }
882 }
883 
884 void NonLocalizedStringChecker::checkPreCall(const CallEvent &Call,
885                                              CheckerContext &C) const {
886   const auto *FD = dyn_cast_or_null<FunctionDecl>(Call.getDecl());
887   if (!FD)
888     return;
889 
890   auto formals = FD->parameters();
891   for (unsigned i = 0, ei = std::min(static_cast<unsigned>(formals.size()),
892                                      Call.getNumArgs()); i != ei; ++i) {
893     if (isAnnotatedAsTakingLocalized(formals[i])) {
894       auto actual = Call.getArgSVal(i);
895       if (hasNonLocalizedState(actual, C)) {
896         reportLocalizationError(actual, Call, C, i + 1);
897       }
898     }
899   }
900 }
901 
902 static inline bool isNSStringType(QualType T, ASTContext &Ctx) {
903 
904   const ObjCObjectPointerType *PT = T->getAs<ObjCObjectPointerType>();
905   if (!PT)
906     return false;
907 
908   ObjCInterfaceDecl *Cls = PT->getObjectType()->getInterface();
909   if (!Cls)
910     return false;
911 
912   IdentifierInfo *ClsName = Cls->getIdentifier();
913 
914   // FIXME: Should we walk the chain of classes?
915   return ClsName == &Ctx.Idents.get("NSString") ||
916          ClsName == &Ctx.Idents.get("NSMutableString");
917 }
918 
919 /// Marks a string being returned by any call as localized
920 /// if it is in LocStringFunctions (LSF) or the function is annotated.
921 /// Otherwise, we mark it as NonLocalized (Aggressive) or
922 /// NonLocalized only if it is not backed by a SymRegion (Non-Aggressive),
923 /// basically leaving only string literals as NonLocalized.
924 void NonLocalizedStringChecker::checkPostCall(const CallEvent &Call,
925                                               CheckerContext &C) const {
926   initLocStringsMethods(C.getASTContext());
927 
928   if (!Call.getOriginExpr())
929     return;
930 
931   // Anything that takes in a localized NSString as an argument
932   // and returns an NSString will be assumed to be returning a
933   // localized NSString. (Counter: Incorrectly combining two LocalizedStrings)
934   const QualType RT = Call.getResultType();
935   if (isNSStringType(RT, C.getASTContext())) {
936     for (unsigned i = 0; i < Call.getNumArgs(); ++i) {
937       SVal argValue = Call.getArgSVal(i);
938       if (hasLocalizedState(argValue, C)) {
939         SVal sv = Call.getReturnValue();
940         setLocalizedState(sv, C);
941         return;
942       }
943     }
944   }
945 
946   const Decl *D = Call.getDecl();
947   if (!D)
948     return;
949 
950   const IdentifierInfo *Identifier = Call.getCalleeIdentifier();
951 
952   SVal sv = Call.getReturnValue();
953   if (isAnnotatedAsReturningLocalized(D) || LSF.contains(Identifier)) {
954     setLocalizedState(sv, C);
955   } else if (isNSStringType(RT, C.getASTContext()) &&
956              !hasLocalizedState(sv, C)) {
957     if (IsAggressive) {
958       setNonLocalizedState(sv, C);
959     } else {
960       const SymbolicRegion *SymReg =
961           dyn_cast_or_null<SymbolicRegion>(sv.getAsRegion());
962       if (!SymReg)
963         setNonLocalizedState(sv, C);
964     }
965   }
966 }
967 
968 /// Marks a string being returned by an ObjC method as localized
969 /// if it is in LocStringMethods or the method is annotated
970 void NonLocalizedStringChecker::checkPostObjCMessage(const ObjCMethodCall &msg,
971                                                      CheckerContext &C) const {
972   initLocStringsMethods(C.getASTContext());
973 
974   if (!msg.isInstanceMessage())
975     return;
976 
977   const ObjCInterfaceDecl *OD = msg.getReceiverInterface();
978   if (!OD)
979     return;
980   const IdentifierInfo *odInfo = OD->getIdentifier();
981 
982   Selector S = msg.getSelector();
983   std::string SelectorName = S.getAsString();
984 
985   std::pair<const IdentifierInfo *, Selector> MethodDescription = {odInfo, S};
986 
987   if (LSM.count(MethodDescription) ||
988       isAnnotatedAsReturningLocalized(msg.getDecl())) {
989     SVal sv = msg.getReturnValue();
990     setLocalizedState(sv, C);
991   }
992 }
993 
994 /// Marks all empty string literals as localized
995 void NonLocalizedStringChecker::checkPostStmt(const ObjCStringLiteral *SL,
996                                               CheckerContext &C) const {
997   SVal sv = C.getSVal(SL);
998   setNonLocalizedState(sv, C);
999 }
1000 
1001 PathDiagnosticPieceRef
1002 NonLocalizedStringBRVisitor::VisitNode(const ExplodedNode *Succ,
1003                                        BugReporterContext &BRC,
1004                                        PathSensitiveBugReport &BR) {
1005   if (Satisfied)
1006     return nullptr;
1007 
1008   std::optional<StmtPoint> Point = Succ->getLocation().getAs<StmtPoint>();
1009   if (!Point)
1010     return nullptr;
1011 
1012   auto *LiteralExpr = dyn_cast<ObjCStringLiteral>(Point->getStmt());
1013   if (!LiteralExpr)
1014     return nullptr;
1015 
1016   SVal LiteralSVal = Succ->getSVal(LiteralExpr);
1017   if (LiteralSVal.getAsRegion() != NonLocalizedString)
1018     return nullptr;
1019 
1020   Satisfied = true;
1021 
1022   PathDiagnosticLocation L =
1023       PathDiagnosticLocation::create(*Point, BRC.getSourceManager());
1024 
1025   if (!L.isValid() || !L.asLocation().isValid())
1026     return nullptr;
1027 
1028   auto Piece = std::make_shared<PathDiagnosticEventPiece>(
1029       L, "Non-localized string literal here");
1030   Piece->addRange(LiteralExpr->getSourceRange());
1031 
1032   return std::move(Piece);
1033 }
1034 
1035 namespace {
1036 class EmptyLocalizationContextChecker
1037     : public Checker<check::ASTDecl<ObjCImplementationDecl>> {
1038 
1039   // A helper class, which walks the AST
1040   class MethodCrawler : public ConstStmtVisitor<MethodCrawler> {
1041     const ObjCMethodDecl *MD;
1042     BugReporter &BR;
1043     AnalysisManager &Mgr;
1044     const CheckerBase *Checker;
1045     LocationOrAnalysisDeclContext DCtx;
1046 
1047   public:
1048     MethodCrawler(const ObjCMethodDecl *InMD, BugReporter &InBR,
1049                   const CheckerBase *Checker, AnalysisManager &InMgr,
1050                   AnalysisDeclContext *InDCtx)
1051         : MD(InMD), BR(InBR), Mgr(InMgr), Checker(Checker), DCtx(InDCtx) {}
1052 
1053     void VisitStmt(const Stmt *S) { VisitChildren(S); }
1054 
1055     void VisitObjCMessageExpr(const ObjCMessageExpr *ME);
1056 
1057     void reportEmptyContextError(const ObjCMessageExpr *M) const;
1058 
1059     void VisitChildren(const Stmt *S) {
1060       for (const Stmt *Child : S->children()) {
1061         if (Child)
1062           this->Visit(Child);
1063       }
1064     }
1065   };
1066 
1067 public:
1068   void checkASTDecl(const ObjCImplementationDecl *D, AnalysisManager &Mgr,
1069                     BugReporter &BR) const;
1070 };
1071 } // end anonymous namespace
1072 
1073 void EmptyLocalizationContextChecker::checkASTDecl(
1074     const ObjCImplementationDecl *D, AnalysisManager &Mgr,
1075     BugReporter &BR) const {
1076 
1077   for (const ObjCMethodDecl *M : D->methods()) {
1078     AnalysisDeclContext *DCtx = Mgr.getAnalysisDeclContext(M);
1079 
1080     const Stmt *Body = M->getBody();
1081     if (!Body) {
1082       assert(M->isSynthesizedAccessorStub());
1083       continue;
1084     }
1085 
1086     MethodCrawler MC(M->getCanonicalDecl(), BR, this, Mgr, DCtx);
1087     MC.VisitStmt(Body);
1088   }
1089 }
1090 
1091 /// This check attempts to match these macros, assuming they are defined as
1092 /// follows:
1093 ///
1094 /// #define NSLocalizedString(key, comment) \
1095 /// [[NSBundle mainBundle] localizedStringForKey:(key) value:@"" table:nil]
1096 /// #define NSLocalizedStringFromTable(key, tbl, comment) \
1097 /// [[NSBundle mainBundle] localizedStringForKey:(key) value:@"" table:(tbl)]
1098 /// #define NSLocalizedStringFromTableInBundle(key, tbl, bundle, comment) \
1099 /// [bundle localizedStringForKey:(key) value:@"" table:(tbl)]
1100 /// #define NSLocalizedStringWithDefaultValue(key, tbl, bundle, val, comment)
1101 ///
1102 /// We cannot use the path sensitive check because the macro argument we are
1103 /// checking for (comment) is not used and thus not present in the AST,
1104 /// so we use Lexer on the original macro call and retrieve the value of
1105 /// the comment. If it's empty or nil, we raise a warning.
1106 void EmptyLocalizationContextChecker::MethodCrawler::VisitObjCMessageExpr(
1107     const ObjCMessageExpr *ME) {
1108 
1109   // FIXME: We may be able to use PPCallbacks to check for empty context
1110   // comments as part of preprocessing and avoid this re-lexing hack.
1111   const ObjCInterfaceDecl *OD = ME->getReceiverInterface();
1112   if (!OD)
1113     return;
1114 
1115   const IdentifierInfo *odInfo = OD->getIdentifier();
1116 
1117   if (!(odInfo->isStr("NSBundle") &&
1118         ME->getSelector().getAsString() ==
1119             "localizedStringForKey:value:table:")) {
1120     return;
1121   }
1122 
1123   SourceRange R = ME->getSourceRange();
1124   if (!R.getBegin().isMacroID())
1125     return;
1126 
1127   // getImmediateMacroCallerLoc gets the location of the immediate macro
1128   // caller, one level up the stack toward the initial macro typed into the
1129   // source, so SL should point to the NSLocalizedString macro.
1130   SourceLocation SL =
1131       Mgr.getSourceManager().getImmediateMacroCallerLoc(R.getBegin());
1132   std::pair<FileID, unsigned> SLInfo =
1133       Mgr.getSourceManager().getDecomposedLoc(SL);
1134 
1135   SrcMgr::SLocEntry SE = Mgr.getSourceManager().getSLocEntry(SLInfo.first);
1136 
1137   // If NSLocalizedString macro is wrapped in another macro, we need to
1138   // unwrap the expansion until we get to the NSLocalizedStringMacro.
1139   while (SE.isExpansion()) {
1140     SL = SE.getExpansion().getSpellingLoc();
1141     SLInfo = Mgr.getSourceManager().getDecomposedLoc(SL);
1142     SE = Mgr.getSourceManager().getSLocEntry(SLInfo.first);
1143   }
1144 
1145   std::optional<llvm::MemoryBufferRef> BF =
1146       Mgr.getSourceManager().getBufferOrNone(SLInfo.first, SL);
1147   if (!BF)
1148     return;
1149   LangOptions LangOpts;
1150   Lexer TheLexer(SL, LangOpts, BF->getBufferStart(),
1151                  BF->getBufferStart() + SLInfo.second, BF->getBufferEnd());
1152 
1153   Token I;
1154   Token Result;    // This will hold the token just before the last ')'
1155   int p_count = 0; // This is for parenthesis matching
1156   while (!TheLexer.LexFromRawLexer(I)) {
1157     if (I.getKind() == tok::l_paren)
1158       ++p_count;
1159     if (I.getKind() == tok::r_paren) {
1160       if (p_count == 1)
1161         break;
1162       --p_count;
1163     }
1164     Result = I;
1165   }
1166 
1167   if (isAnyIdentifier(Result.getKind())) {
1168     if (Result.getRawIdentifier().equals("nil")) {
1169       reportEmptyContextError(ME);
1170       return;
1171     }
1172   }
1173 
1174   if (!isStringLiteral(Result.getKind()))
1175     return;
1176 
1177   StringRef Comment =
1178       StringRef(Result.getLiteralData(), Result.getLength()).trim('"');
1179 
1180   if ((Comment.trim().size() == 0 && Comment.size() > 0) || // Is Whitespace
1181       Comment.empty()) {
1182     reportEmptyContextError(ME);
1183   }
1184 }
1185 
1186 void EmptyLocalizationContextChecker::MethodCrawler::reportEmptyContextError(
1187     const ObjCMessageExpr *ME) const {
1188   // Generate the bug report.
1189   BR.EmitBasicReport(MD, Checker, "Context Missing",
1190                      "Localizability Issue (Apple)",
1191                      "Localized string macro should include a non-empty "
1192                      "comment for translators",
1193                      PathDiagnosticLocation(ME, BR.getSourceManager(), DCtx));
1194 }
1195 
1196 namespace {
1197 class PluralMisuseChecker : public Checker<check::ASTCodeBody> {
1198 
1199   // A helper class, which walks the AST
1200   class MethodCrawler : public RecursiveASTVisitor<MethodCrawler> {
1201     BugReporter &BR;
1202     const CheckerBase *Checker;
1203     AnalysisDeclContext *AC;
1204 
1205     // This functions like a stack. We push on any IfStmt or
1206     // ConditionalOperator that matches the condition
1207     // and pop it off when we leave that statement
1208     llvm::SmallVector<const clang::Stmt *, 8> MatchingStatements;
1209     // This is true when we are the direct-child of a
1210     // matching statement
1211     bool InMatchingStatement = false;
1212 
1213   public:
1214     explicit MethodCrawler(BugReporter &InBR, const CheckerBase *Checker,
1215                            AnalysisDeclContext *InAC)
1216         : BR(InBR), Checker(Checker), AC(InAC) {}
1217 
1218     bool VisitIfStmt(const IfStmt *I);
1219     bool EndVisitIfStmt(IfStmt *I);
1220     bool TraverseIfStmt(IfStmt *x);
1221     bool VisitConditionalOperator(const ConditionalOperator *C);
1222     bool TraverseConditionalOperator(ConditionalOperator *C);
1223     bool VisitCallExpr(const CallExpr *CE);
1224     bool VisitObjCMessageExpr(const ObjCMessageExpr *ME);
1225 
1226   private:
1227     void reportPluralMisuseError(const Stmt *S) const;
1228     bool isCheckingPlurality(const Expr *E) const;
1229   };
1230 
1231 public:
1232   void checkASTCodeBody(const Decl *D, AnalysisManager &Mgr,
1233                         BugReporter &BR) const {
1234     MethodCrawler Visitor(BR, this, Mgr.getAnalysisDeclContext(D));
1235     Visitor.TraverseDecl(const_cast<Decl *>(D));
1236   }
1237 };
1238 } // end anonymous namespace
1239 
1240 // Checks the condition of the IfStmt and returns true if one
1241 // of the following heuristics are met:
1242 // 1) The conidtion is a variable with "singular" or "plural" in the name
1243 // 2) The condition is a binary operator with 1 or 2 on the right-hand side
1244 bool PluralMisuseChecker::MethodCrawler::isCheckingPlurality(
1245     const Expr *Condition) const {
1246   const BinaryOperator *BO = nullptr;
1247   // Accounts for when a VarDecl represents a BinaryOperator
1248   if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Condition)) {
1249     if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) {
1250       const Expr *InitExpr = VD->getInit();
1251       if (InitExpr) {
1252         if (const BinaryOperator *B =
1253                 dyn_cast<BinaryOperator>(InitExpr->IgnoreParenImpCasts())) {
1254           BO = B;
1255         }
1256       }
1257       if (VD->getName().lower().find("plural") != StringRef::npos ||
1258           VD->getName().lower().find("singular") != StringRef::npos) {
1259         return true;
1260       }
1261     }
1262   } else if (const BinaryOperator *B = dyn_cast<BinaryOperator>(Condition)) {
1263     BO = B;
1264   }
1265 
1266   if (BO == nullptr)
1267     return false;
1268 
1269   if (IntegerLiteral *IL = dyn_cast_or_null<IntegerLiteral>(
1270           BO->getRHS()->IgnoreParenImpCasts())) {
1271     llvm::APInt Value = IL->getValue();
1272     if (Value == 1 || Value == 2) {
1273       return true;
1274     }
1275   }
1276   return false;
1277 }
1278 
1279 // A CallExpr with "LOC" in its identifier that takes in a string literal
1280 // has been shown to almost always be a function that returns a localized
1281 // string. Raise a diagnostic when this is in a statement that matches
1282 // the condition.
1283 bool PluralMisuseChecker::MethodCrawler::VisitCallExpr(const CallExpr *CE) {
1284   if (InMatchingStatement) {
1285     if (const FunctionDecl *FD = CE->getDirectCallee()) {
1286       std::string NormalizedName =
1287           StringRef(FD->getNameInfo().getAsString()).lower();
1288       if (NormalizedName.find("loc") != std::string::npos) {
1289         for (const Expr *Arg : CE->arguments()) {
1290           if (isa<ObjCStringLiteral>(Arg))
1291             reportPluralMisuseError(CE);
1292         }
1293       }
1294     }
1295   }
1296   return true;
1297 }
1298 
1299 // The other case is for NSLocalizedString which also returns
1300 // a localized string. It's a macro for the ObjCMessageExpr
1301 // [NSBundle localizedStringForKey:value:table:] Raise a
1302 // diagnostic when this is in a statement that matches
1303 // the condition.
1304 bool PluralMisuseChecker::MethodCrawler::VisitObjCMessageExpr(
1305     const ObjCMessageExpr *ME) {
1306   const ObjCInterfaceDecl *OD = ME->getReceiverInterface();
1307   if (!OD)
1308     return true;
1309 
1310   const IdentifierInfo *odInfo = OD->getIdentifier();
1311 
1312   if (odInfo->isStr("NSBundle") &&
1313       ME->getSelector().getAsString() == "localizedStringForKey:value:table:") {
1314     if (InMatchingStatement) {
1315       reportPluralMisuseError(ME);
1316     }
1317   }
1318   return true;
1319 }
1320 
1321 /// Override TraverseIfStmt so we know when we are done traversing an IfStmt
1322 bool PluralMisuseChecker::MethodCrawler::TraverseIfStmt(IfStmt *I) {
1323   RecursiveASTVisitor<MethodCrawler>::TraverseIfStmt(I);
1324   return EndVisitIfStmt(I);
1325 }
1326 
1327 // EndVisit callbacks are not provided by the RecursiveASTVisitor
1328 // so we override TraverseIfStmt and make a call to EndVisitIfStmt
1329 // after traversing the IfStmt
1330 bool PluralMisuseChecker::MethodCrawler::EndVisitIfStmt(IfStmt *I) {
1331   MatchingStatements.pop_back();
1332   if (!MatchingStatements.empty()) {
1333     if (MatchingStatements.back() != nullptr) {
1334       InMatchingStatement = true;
1335       return true;
1336     }
1337   }
1338   InMatchingStatement = false;
1339   return true;
1340 }
1341 
1342 bool PluralMisuseChecker::MethodCrawler::VisitIfStmt(const IfStmt *I) {
1343   const Expr *Condition = I->getCond();
1344   if (!Condition)
1345     return true;
1346   Condition = Condition->IgnoreParenImpCasts();
1347   if (isCheckingPlurality(Condition)) {
1348     MatchingStatements.push_back(I);
1349     InMatchingStatement = true;
1350   } else {
1351     MatchingStatements.push_back(nullptr);
1352     InMatchingStatement = false;
1353   }
1354 
1355   return true;
1356 }
1357 
1358 // Preliminary support for conditional operators.
1359 bool PluralMisuseChecker::MethodCrawler::TraverseConditionalOperator(
1360     ConditionalOperator *C) {
1361   RecursiveASTVisitor<MethodCrawler>::TraverseConditionalOperator(C);
1362   MatchingStatements.pop_back();
1363   if (!MatchingStatements.empty()) {
1364     if (MatchingStatements.back() != nullptr)
1365       InMatchingStatement = true;
1366     else
1367       InMatchingStatement = false;
1368   } else {
1369     InMatchingStatement = false;
1370   }
1371   return true;
1372 }
1373 
1374 bool PluralMisuseChecker::MethodCrawler::VisitConditionalOperator(
1375     const ConditionalOperator *C) {
1376   const Expr *Condition = C->getCond()->IgnoreParenImpCasts();
1377   if (isCheckingPlurality(Condition)) {
1378     MatchingStatements.push_back(C);
1379     InMatchingStatement = true;
1380   } else {
1381     MatchingStatements.push_back(nullptr);
1382     InMatchingStatement = false;
1383   }
1384   return true;
1385 }
1386 
1387 void PluralMisuseChecker::MethodCrawler::reportPluralMisuseError(
1388     const Stmt *S) const {
1389   // Generate the bug report.
1390   BR.EmitBasicReport(AC->getDecl(), Checker, "Plural Misuse",
1391                      "Localizability Issue (Apple)",
1392                      "Plural cases are not supported across all languages. "
1393                      "Use a .stringsdict file instead",
1394                      PathDiagnosticLocation(S, BR.getSourceManager(), AC));
1395 }
1396 
1397 //===----------------------------------------------------------------------===//
1398 // Checker registration.
1399 //===----------------------------------------------------------------------===//
1400 
1401 void ento::registerNonLocalizedStringChecker(CheckerManager &mgr) {
1402   NonLocalizedStringChecker *checker =
1403       mgr.registerChecker<NonLocalizedStringChecker>();
1404   checker->IsAggressive =
1405       mgr.getAnalyzerOptions().getCheckerBooleanOption(
1406           checker, "AggressiveReport");
1407 }
1408 
1409 bool ento::shouldRegisterNonLocalizedStringChecker(const CheckerManager &mgr) {
1410   return true;
1411 }
1412 
1413 void ento::registerEmptyLocalizationContextChecker(CheckerManager &mgr) {
1414   mgr.registerChecker<EmptyLocalizationContextChecker>();
1415 }
1416 
1417 bool ento::shouldRegisterEmptyLocalizationContextChecker(
1418                                                     const CheckerManager &mgr) {
1419   return true;
1420 }
1421 
1422 void ento::registerPluralMisuseChecker(CheckerManager &mgr) {
1423   mgr.registerChecker<PluralMisuseChecker>();
1424 }
1425 
1426 bool ento::shouldRegisterPluralMisuseChecker(const CheckerManager &mgr) {
1427   return true;
1428 }
1429