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1 // RUN: %clang_cc1 -analyze -analyzer-checker=core,alpha.deadcode.UnreachableCode,alpha.core.CastSize,unix.Malloc,debug.ExprInspection -analyzer-store=region -verify %s
2 
3 #include "Inputs/system-header-simulator.h"
4 
5 void clang_analyzer_eval(int);
6 
7 typedef __typeof(sizeof(int)) size_t;
8 void *malloc(size_t);
9 void *valloc(size_t);
10 void free(void *);
11 void *realloc(void *ptr, size_t size);
12 void *reallocf(void *ptr, size_t size);
13 void *calloc(size_t nmemb, size_t size);
14 char *strdup(const char *s);
15 char *strndup(const char *s, size_t n);
16 int memcmp(const void *s1, const void *s2, size_t n);
17 
18 void myfoo(int *p);
19 void myfooint(int p);
20 char *fooRetPtr();
21 
f1()22 void f1() {
23   int *p = malloc(12);
24   return; // expected-warning{{Potential leak of memory pointed to by 'p'}}
25 }
26 
f2()27 void f2() {
28   int *p = malloc(12);
29   free(p);
30   free(p); // expected-warning{{Attempt to free released memory}}
31 }
32 
f2_realloc_0()33 void f2_realloc_0() {
34   int *p = malloc(12);
35   realloc(p,0);
36   realloc(p,0); // expected-warning{{Attempt to free released memory}}
37 }
38 
f2_realloc_1()39 void f2_realloc_1() {
40   int *p = malloc(12);
41   int *q = realloc(p,0); // no-warning
42 }
43 
reallocNotNullPtr(unsigned sizeIn)44 void reallocNotNullPtr(unsigned sizeIn) {
45   unsigned size = 12;
46   char *p = (char*)malloc(size);
47   if (p) {
48     char *q = (char*)realloc(p, sizeIn);
49     char x = *q; // expected-warning {{Potential leak of memory pointed to by 'q'}}
50   }
51 }
52 
realloctest1()53 int *realloctest1() {
54   int *q = malloc(12);
55   q = realloc(q, 20);
56   return q; // no warning - returning the allocated value
57 }
58 
59 // p should be freed if realloc fails.
reallocFails()60 void reallocFails() {
61   char *p = malloc(12);
62   char *r = realloc(p, 12+1);
63   if (!r) {
64     free(p);
65   } else {
66     free(r);
67   }
68 }
69 
reallocSizeZero1()70 void reallocSizeZero1() {
71   char *p = malloc(12);
72   char *r = realloc(p, 0);
73   if (!r) {
74     free(p); // expected-warning {{Attempt to free released memory}}
75   } else {
76     free(r);
77   }
78 }
79 
reallocSizeZero2()80 void reallocSizeZero2() {
81   char *p = malloc(12);
82   char *r = realloc(p, 0);
83   if (!r) {
84     free(p); // expected-warning {{Attempt to free released memory}}
85   } else {
86     free(r);
87   }
88   free(p); // expected-warning {{Attempt to free released memory}}
89 }
90 
reallocSizeZero3()91 void reallocSizeZero3() {
92   char *p = malloc(12);
93   char *r = realloc(p, 0);
94   free(r);
95 }
96 
reallocSizeZero4()97 void reallocSizeZero4() {
98   char *r = realloc(0, 0);
99   free(r);
100 }
101 
reallocSizeZero5()102 void reallocSizeZero5() {
103   char *r = realloc(0, 0);
104 }
105 
reallocPtrZero1()106 void reallocPtrZero1() {
107   char *r = realloc(0, 12);
108 } // expected-warning {{Potential leak of memory pointed to by 'r'}}
109 
reallocPtrZero2()110 void reallocPtrZero2() {
111   char *r = realloc(0, 12);
112   if (r)
113     free(r);
114 }
115 
reallocPtrZero3()116 void reallocPtrZero3() {
117   char *r = realloc(0, 12);
118   free(r);
119 }
120 
reallocRadar6337483_1()121 void reallocRadar6337483_1() {
122     char *buf = malloc(100);
123     buf = (char*)realloc(buf, 0x1000000);
124     if (!buf) {
125         return;// expected-warning {{Potential leak of memory pointed to by}}
126     }
127     free(buf);
128 }
129 
reallocRadar6337483_2()130 void reallocRadar6337483_2() {
131     char *buf = malloc(100);
132     char *buf2 = (char*)realloc(buf, 0x1000000);
133     if (!buf2) {
134       ;
135     } else {
136       free(buf2);
137     }
138 } // expected-warning {{Potential leak of memory pointed to by}}
139 
reallocRadar6337483_3()140 void reallocRadar6337483_3() {
141     char * buf = malloc(100);
142     char * tmp;
143     tmp = (char*)realloc(buf, 0x1000000);
144     if (!tmp) {
145         free(buf);
146         return;
147     }
148     buf = tmp;
149     free(buf);
150 }
151 
reallocRadar6337483_4()152 void reallocRadar6337483_4() {
153     char *buf = malloc(100);
154     char *buf2 = (char*)realloc(buf, 0x1000000);
155     if (!buf2) {
156       return;  // expected-warning {{Potential leak of memory pointed to by}}
157     } else {
158       free(buf2);
159     }
160 }
161 
reallocfTest1()162 int *reallocfTest1() {
163   int *q = malloc(12);
164   q = reallocf(q, 20);
165   return q; // no warning - returning the allocated value
166 }
167 
reallocfRadar6337483_4()168 void reallocfRadar6337483_4() {
169     char *buf = malloc(100);
170     char *buf2 = (char*)reallocf(buf, 0x1000000);
171     if (!buf2) {
172       return;  // no warning - reallocf frees even on failure
173     } else {
174       free(buf2);
175     }
176 }
177 
reallocfRadar6337483_3()178 void reallocfRadar6337483_3() {
179     char * buf = malloc(100);
180     char * tmp;
181     tmp = (char*)reallocf(buf, 0x1000000);
182     if (!tmp) {
183         free(buf); // expected-warning {{Attempt to free released memory}}
184         return;
185     }
186     buf = tmp;
187     free(buf);
188 }
189 
reallocfPtrZero1()190 void reallocfPtrZero1() {
191   char *r = reallocf(0, 12);
192 } // expected-warning {{Potential leak of memory pointed to by}}
193 
194 
195 // This case tests that storing malloc'ed memory to a static variable which is
196 // then returned is not leaked.  In the absence of known contracts for functions
197 // or inter-procedural analysis, this is a conservative answer.
f3()198 int *f3() {
199   static int *p = 0;
200   p = malloc(12);
201   return p; // no-warning
202 }
203 
204 // This case tests that storing malloc'ed memory to a static global variable
205 // which is then returned is not leaked.  In the absence of known contracts for
206 // functions or inter-procedural analysis, this is a conservative answer.
207 static int *p_f4 = 0;
f4()208 int *f4() {
209   p_f4 = malloc(12);
210   return p_f4; // no-warning
211 }
212 
f5()213 int *f5() {
214   int *q = malloc(12);
215   q = realloc(q, 20);
216   return q; // no-warning
217 }
218 
f6()219 void f6() {
220   int *p = malloc(12);
221   if (!p)
222     return; // no-warning
223   else
224     free(p);
225 }
226 
f6_realloc()227 void f6_realloc() {
228   int *p = malloc(12);
229   if (!p)
230     return; // no-warning
231   else
232     realloc(p,0);
233 }
234 
235 
236 char *doit2();
pr6069()237 void pr6069() {
238   char *buf = doit2();
239   free(buf);
240 }
241 
pr6293()242 void pr6293() {
243   free(0);
244 }
245 
f7()246 void f7() {
247   char *x = (char*) malloc(4);
248   free(x);
249   x[0] = 'a'; // expected-warning{{Use of memory after it is freed}}
250 }
251 
f8()252 void f8() {
253   char *x = (char*) malloc(4);
254   free(x);
255   char *y = strndup(x, 4); // expected-warning{{Use of memory after it is freed}}
256 }
257 
f7_realloc()258 void f7_realloc() {
259   char *x = (char*) malloc(4);
260   realloc(x,0);
261   x[0] = 'a'; // expected-warning{{Use of memory after it is freed}}
262 }
263 
PR6123()264 void PR6123() {
265   int *x = malloc(11); // expected-warning{{Cast a region whose size is not a multiple of the destination type size}}
266 }
267 
PR7217()268 void PR7217() {
269   int *buf = malloc(2); // expected-warning{{Cast a region whose size is not a multiple of the destination type size}}
270   buf[1] = 'c'; // not crash
271 }
272 
mallocCastToVoid()273 void mallocCastToVoid() {
274   void *p = malloc(2);
275   const void *cp = p; // not crash
276   free(p);
277 }
278 
mallocCastToFP()279 void mallocCastToFP() {
280   void *p = malloc(2);
281   void (*fp)() = p; // not crash
282   free(p);
283 }
284 
285 // This tests that malloc() buffers are undefined by default
mallocGarbage()286 char mallocGarbage () {
287 	char *buf = malloc(2);
288 	char result = buf[1]; // expected-warning{{undefined}}
289 	free(buf);
290 	return result;
291 }
292 
293 // This tests that calloc() buffers need to be freed
callocNoFree()294 void callocNoFree () {
295   char *buf = calloc(2,2);
296   return; // expected-warning{{Potential leak of memory pointed to by 'buf'}}
297 }
298 
299 // These test that calloc() buffers are zeroed by default
callocZeroesGood()300 char callocZeroesGood () {
301 	char *buf = calloc(2,2);
302 	char result = buf[3]; // no-warning
303 	if (buf[1] == 0) {
304 	  free(buf);
305 	}
306 	return result; // no-warning
307 }
308 
callocZeroesBad()309 char callocZeroesBad () {
310 	char *buf = calloc(2,2);
311 	char result = buf[3]; // no-warning
312 	if (buf[1] != 0) {
313 	  free(buf); // expected-warning{{never executed}}
314 	}
315 	return result; // expected-warning{{Potential leak of memory pointed to by 'buf'}}
316 }
317 
nullFree()318 void nullFree() {
319   int *p = 0;
320   free(p); // no warning - a nop
321 }
322 
paramFree(int * p)323 void paramFree(int *p) {
324   myfoo(p);
325   free(p); // no warning
326   myfoo(p); // expected-warning {{Use of memory after it is freed}}
327 }
328 
mallocEscapeRet()329 int* mallocEscapeRet() {
330   int *p = malloc(12);
331   return p; // no warning
332 }
333 
mallocEscapeFoo()334 void mallocEscapeFoo() {
335   int *p = malloc(12);
336   myfoo(p);
337   return; // no warning
338 }
339 
mallocEscapeFree()340 void mallocEscapeFree() {
341   int *p = malloc(12);
342   myfoo(p);
343   free(p);
344 }
345 
mallocEscapeFreeFree()346 void mallocEscapeFreeFree() {
347   int *p = malloc(12);
348   myfoo(p);
349   free(p);
350   free(p); // expected-warning{{Attempt to free released memory}}
351 }
352 
mallocEscapeFreeUse()353 void mallocEscapeFreeUse() {
354   int *p = malloc(12);
355   myfoo(p);
356   free(p);
357   myfoo(p); // expected-warning{{Use of memory after it is freed}}
358 }
359 
360 int *myalloc();
361 void myalloc2(int **p);
362 
mallocEscapeFreeCustomAlloc()363 void mallocEscapeFreeCustomAlloc() {
364   int *p = malloc(12);
365   myfoo(p);
366   free(p);
367   p = myalloc();
368   free(p); // no warning
369 }
370 
mallocEscapeFreeCustomAlloc2()371 void mallocEscapeFreeCustomAlloc2() {
372   int *p = malloc(12);
373   myfoo(p);
374   free(p);
375   myalloc2(&p);
376   free(p); // no warning
377 }
378 
mallocBindFreeUse()379 void mallocBindFreeUse() {
380   int *x = malloc(12);
381   int *y = x;
382   free(y);
383   myfoo(x); // expected-warning{{Use of memory after it is freed}}
384 }
385 
mallocEscapeMalloc()386 void mallocEscapeMalloc() {
387   int *p = malloc(12);
388   myfoo(p);
389   p = malloc(12);
390 } // expected-warning{{Potential leak of memory pointed to by}}
391 
mallocMalloc()392 void mallocMalloc() {
393   int *p = malloc(12);
394   p = malloc(12);
395 } // expected-warning {{Potential leak of memory pointed to by}}
396 
mallocFreeMalloc()397 void mallocFreeMalloc() {
398   int *p = malloc(12);
399   free(p);
400   p = malloc(12);
401   free(p);
402 }
403 
mallocFreeUse_params()404 void mallocFreeUse_params() {
405   int *p = malloc(12);
406   free(p);
407   myfoo(p); //expected-warning{{Use of memory after it is freed}}
408 }
409 
mallocFreeUse_params2()410 void mallocFreeUse_params2() {
411   int *p = malloc(12);
412   free(p);
413   myfooint(*p); //expected-warning{{Use of memory after it is freed}}
414 }
415 
mallocFailedOrNot()416 void mallocFailedOrNot() {
417   int *p = malloc(12);
418   if (!p)
419     free(p);
420   else
421     free(p);
422 }
423 
424 struct StructWithInt {
425   int g;
426 };
427 
mallocReturnFreed()428 int *mallocReturnFreed() {
429   int *p = malloc(12);
430   free(p);
431   return p; // expected-warning {{Use of memory after it is freed}}
432 }
433 
useAfterFreeStruct()434 int useAfterFreeStruct() {
435   struct StructWithInt *px= malloc(sizeof(struct StructWithInt));
436   px->g = 5;
437   free(px);
438   return px->g; // expected-warning {{Use of memory after it is freed}}
439 }
440 
441 void nonSymbolAsFirstArg(int *pp, struct StructWithInt *p);
442 
mallocEscapeFooNonSymbolArg()443 void mallocEscapeFooNonSymbolArg() {
444   struct StructWithInt *p = malloc(sizeof(struct StructWithInt));
445   nonSymbolAsFirstArg(&p->g, p);
446   return; // no warning
447 }
448 
mallocFailedOrNotLeak()449 void mallocFailedOrNotLeak() {
450   int *p = malloc(12);
451   if (p == 0)
452     return; // no warning
453   else
454     return; // expected-warning {{Potential leak of memory pointed to by}}
455 }
456 
mallocAssignment()457 void mallocAssignment() {
458   char *p = malloc(12);
459   p = fooRetPtr();
460 } // expected-warning {{leak}}
461 
vallocTest()462 int vallocTest() {
463   char *mem = valloc(12);
464   return 0; // expected-warning {{Potential leak of memory pointed to by}}
465 }
466 
vallocEscapeFreeUse()467 void vallocEscapeFreeUse() {
468   int *p = valloc(12);
469   myfoo(p);
470   free(p);
471   myfoo(p); // expected-warning{{Use of memory after it is freed}}
472 }
473 
474 int *Gl;
475 struct GlStTy {
476   int *x;
477 };
478 
479 struct GlStTy GlS = {0};
480 
GlobalFree()481 void GlobalFree() {
482   free(Gl);
483 }
484 
GlobalMalloc()485 void GlobalMalloc() {
486   Gl = malloc(12);
487 }
488 
GlobalStructMalloc()489 void GlobalStructMalloc() {
490   int *a = malloc(12);
491   GlS.x = a;
492 }
493 
GlobalStructMallocFree()494 void GlobalStructMallocFree() {
495   int *a = malloc(12);
496   GlS.x = a;
497   free(GlS.x);
498 }
499 
500 char *ArrayG[12];
501 
globalArrayTest()502 void globalArrayTest() {
503   char *p = (char*)malloc(12);
504   ArrayG[0] = p;
505 }
506 
507 // Make sure that we properly handle a pointer stored into a local struct/array.
508 typedef struct _StructWithPtr {
509   int *memP;
510 } StructWithPtr;
511 
512 static StructWithPtr arrOfStructs[10];
513 
testMalloc()514 void testMalloc() {
515   int *x = malloc(12);
516   StructWithPtr St;
517   St.memP = x;
518   arrOfStructs[0] = St; // no-warning
519 }
520 
testMalloc2()521 StructWithPtr testMalloc2() {
522   int *x = malloc(12);
523   StructWithPtr St;
524   St.memP = x;
525   return St; // no-warning
526 }
527 
testMalloc3()528 int *testMalloc3() {
529   int *x = malloc(12);
530   int *y = x;
531   return y; // no-warning
532 }
533 
testStructLeak()534 void testStructLeak() {
535   StructWithPtr St;
536   St.memP = malloc(12);
537   return; // expected-warning {{Potential leak of memory pointed to by 'St.memP'}}
538 }
539 
testElemRegion1()540 void testElemRegion1() {
541   char *x = (void*)malloc(2);
542   int *ix = (int*)x;
543   free(&(x[0]));
544 }
545 
testElemRegion2(int ** pp)546 void testElemRegion2(int **pp) {
547   int *p = malloc(12);
548   *pp = p;
549   free(pp[0]);
550 }
551 
testElemRegion3(int ** pp)552 void testElemRegion3(int **pp) {
553   int *p = malloc(12);
554   *pp = p;
555   free(*pp);
556 }
557 // Region escape testing.
558 
559 unsigned takePtrToPtr(int **p);
PassTheAddrOfAllocatedData(int f)560 void PassTheAddrOfAllocatedData(int f) {
561   int *p = malloc(12);
562   // We don't know what happens after the call. Should stop tracking here.
563   if (takePtrToPtr(&p))
564     f++;
565   free(p); // no warning
566 }
567 
568 struct X {
569   int *p;
570 };
571 unsigned takePtrToStruct(struct X *s);
foo2(int * g,int f)572 int ** foo2(int *g, int f) {
573   int *p = malloc(12);
574   struct X *px= malloc(sizeof(struct X));
575   px->p = p;
576   // We don't know what happens after this call. Should not track px nor p.
577   if (takePtrToStruct(px))
578     f++;
579   free(p);
580   return 0;
581 }
582 
RegInvalidationDetect1(struct X * s2)583 struct X* RegInvalidationDetect1(struct X *s2) {
584   struct X *px= malloc(sizeof(struct X));
585   px->p = 0;
586   px = s2;
587   return px; // expected-warning {{Potential leak of memory pointed to by}}
588 }
589 
RegInvalidationGiveUp1()590 struct X* RegInvalidationGiveUp1() {
591   int *p = malloc(12);
592   struct X *px= malloc(sizeof(struct X));
593   px->p = p;
594   return px;
595 }
596 
RegInvalidationDetect2(int ** pp)597 int **RegInvalidationDetect2(int **pp) {
598   int *p = malloc(12);
599   pp = &p;
600   pp++;
601   return 0;// expected-warning {{Potential leak of memory pointed to by}}
602 }
603 
604 extern void exit(int) __attribute__ ((__noreturn__));
mallocExit(int * g)605 void mallocExit(int *g) {
606   struct xx *p = malloc(12);
607   if (g != 0)
608     exit(1);
609   free(p);
610   return;
611 }
612 
613 extern void __assert_fail (__const char *__assertion, __const char *__file,
614     unsigned int __line, __const char *__function)
615      __attribute__ ((__noreturn__));
616 #define assert(expr) \
617   ((expr)  ? (void)(0)  : __assert_fail (#expr, __FILE__, __LINE__, __func__))
mallocAssert(int * g)618 void mallocAssert(int *g) {
619   struct xx *p = malloc(12);
620 
621   assert(g != 0);
622   free(p);
623   return;
624 }
625 
doNotInvalidateWhenPassedToSystemCalls(char * s)626 void doNotInvalidateWhenPassedToSystemCalls(char *s) {
627   char *p = malloc(12);
628   strlen(p);
629   strcpy(p, s);
630 } // expected-warning {{leak}}
631 
632 // Rely on the CString checker evaluation of the strcpy API to convey that the result of strcpy is equal to p.
symbolLostWithStrcpy(char * s)633 void symbolLostWithStrcpy(char *s) {
634   char *p = malloc(12);
635   p = strcpy(p, s);
636   free(p);
637 }
638 
639 
640 // The same test as the one above, but with what is actually generated on a mac.
641 static __inline char *
__inline_strcpy_chk(char * restrict __dest,const char * restrict __src)642 __inline_strcpy_chk (char *restrict __dest, const char *restrict __src)
643 {
644   return __builtin___strcpy_chk (__dest, __src, __builtin_object_size (__dest, 2 > 1));
645 }
646 
symbolLostWithStrcpy_InlineStrcpyVersion(char * s)647 void symbolLostWithStrcpy_InlineStrcpyVersion(char *s) {
648   char *p = malloc(12);
649   p = ((__builtin_object_size (p, 0) != (size_t) -1) ? __builtin___strcpy_chk (p, s, __builtin_object_size (p, 2 > 1)) : __inline_strcpy_chk (p, s));
650   free(p);
651 }
652 
653 // Here we are returning a pointer one past the allocated value. An idiom which
654 // can be used for implementing special malloc. The correct uses of this might
655 // be rare enough so that we could keep this as a warning.
specialMalloc(int n)656 static void *specialMalloc(int n){
657   int *p;
658   p = malloc( n+8 );
659   if( p ){
660     p[0] = n;
661     p++;
662   }
663   return p;
664 }
665 
666 // Potentially, the user could free the struct by performing pointer arithmetic on the return value.
667 // This is a variation of the specialMalloc issue, though probably would be more rare in correct code.
specialMallocWithStruct()668 int *specialMallocWithStruct() {
669   struct StructWithInt *px= malloc(sizeof(struct StructWithInt));
670   return &(px->g);
671 }
672 
673 // Test various allocation/deallocation functions.
testStrdup(const char * s,unsigned validIndex)674 void testStrdup(const char *s, unsigned validIndex) {
675   char *s2 = strdup(s);
676   s2[validIndex + 1] = 'b';
677 } // expected-warning {{Potential leak of memory pointed to by}}
678 
testStrndup(const char * s,unsigned validIndex,unsigned size)679 int testStrndup(const char *s, unsigned validIndex, unsigned size) {
680   char *s2 = strndup(s, size);
681   s2 [validIndex + 1] = 'b';
682   if (s2[validIndex] != 'a')
683     return 0;
684   else
685     return 1;// expected-warning {{Potential leak of memory pointed to by}}
686 }
687 
testStrdupContentIsDefined(const char * s,unsigned validIndex)688 void testStrdupContentIsDefined(const char *s, unsigned validIndex) {
689   char *s2 = strdup(s);
690   char result = s2[1];// no warning
691   free(s2);
692 }
693 
694 // ----------------------------------------------------------------------------
695 // Test the system library functions to which the pointer can escape.
696 // This tests false positive suppression.
697 
698 // For now, we assume memory passed to pthread_specific escapes.
699 // TODO: We could check that if a new pthread binding is set, the existing
700 // binding must be freed; otherwise, a memory leak can occur.
testPthereadSpecificEscape(pthread_key_t key)701 void testPthereadSpecificEscape(pthread_key_t key) {
702   void *buf = malloc(12);
703   pthread_setspecific(key, buf); // no warning
704 }
705 
706 // PR12101: Test funopen().
releasePtr(void * _ctx)707 static int releasePtr(void *_ctx) {
708     free(_ctx);
709     return 0;
710 }
useFunOpen()711 FILE *useFunOpen() {
712     void *ctx = malloc(sizeof(int));
713     FILE *f = funopen(ctx, 0, 0, 0, releasePtr); // no warning
714     if (f == 0) {
715         free(ctx);
716     }
717     return f;
718 }
useFunOpenNoReleaseFunction()719 FILE *useFunOpenNoReleaseFunction() {
720     void *ctx = malloc(sizeof(int));
721     FILE *f = funopen(ctx, 0, 0, 0, 0);
722     if (f == 0) {
723         free(ctx);
724     }
725     return f; // expected-warning{{leak}}
726 }
727 
readNothing(void * _ctx,char * buf,int size)728 static int readNothing(void *_ctx, char *buf, int size) {
729   return 0;
730 }
useFunOpenReadNoRelease()731 FILE *useFunOpenReadNoRelease() {
732   void *ctx = malloc(sizeof(int));
733   FILE *f = funopen(ctx, readNothing, 0, 0, 0);
734   if (f == 0) {
735     free(ctx);
736   }
737   return f; // expected-warning{{leak}}
738 }
739 
740 // Test setbuf, setvbuf.
my_main_no_warning()741 int my_main_no_warning() {
742     char *p = malloc(100);
743     setvbuf(stdout, p, 0, 100);
744     return 0;
745 }
my_main_no_warning2()746 int my_main_no_warning2() {
747     char *p = malloc(100);
748     setbuf(__stdoutp, p);
749     return 0;
750 }
my_main_warn(FILE * f)751 int my_main_warn(FILE *f) {
752     char *p = malloc(100);
753     setvbuf(f, p, 0, 100);
754     return 0;// expected-warning {{leak}}
755 }
756 
757 // <rdar://problem/10978247>.
758 // some people use stack allocated memory as an optimization to avoid
759 // a heap allocation for small work sizes.  This tests the analyzer's
760 // understanding that the malloc'ed memory is not the same as stackBuffer.
radar10978247(int myValueSize)761 void radar10978247(int myValueSize) {
762   char stackBuffer[128];
763   char *buffer;
764 
765   if (myValueSize <= sizeof(stackBuffer))
766     buffer = stackBuffer;
767   else
768     buffer = malloc(myValueSize);
769 
770   // do stuff with the buffer
771   if (buffer != stackBuffer)
772     free(buffer);
773 }
774 
radar10978247_positive(int myValueSize)775 void radar10978247_positive(int myValueSize) {
776   char stackBuffer[128];
777   char *buffer;
778 
779   if (myValueSize <= sizeof(stackBuffer))
780     buffer = stackBuffer;
781   else
782     buffer = malloc(myValueSize);
783 
784   // do stuff with the buffer
785   if (buffer == stackBuffer)
786     return;
787   else
788     return; // expected-warning {{leak}}
789 }
790 // <rdar://problem/11269741> Previously this triggered a false positive
791 // because malloc() is known to return uninitialized memory and the binding
792 // of 'o' to 'p->n' was not getting propertly handled.  Now we report a leak.
793 struct rdar11269741_a_t {
794   struct rdar11269741_b_t {
795     int m;
796   } n;
797 };
798 
rdar11269741(struct rdar11269741_b_t o)799 int rdar11269741(struct rdar11269741_b_t o)
800 {
801   struct rdar11269741_a_t *p = (struct rdar11269741_a_t *) malloc(sizeof(*p));
802   p->n = o;
803   return p->n.m; // expected-warning {{leak}}
804 }
805 
806 // Pointer arithmetic, returning an ElementRegion.
radar11329382(unsigned bl)807 void *radar11329382(unsigned bl) {
808   void *ptr = malloc (16);
809   ptr = ptr + (2 - bl);
810   return ptr; // no warning
811 }
812 
813 void __assert_rtn(const char *, const char *, int, const char *) __attribute__((__noreturn__));
814 int strcmp(const char *, const char *);
815 char *a (void);
radar11270219(void)816 void radar11270219(void) {
817   char *x = a(), *y = a();
818   (__builtin_expect(!(x && y), 0) ? __assert_rtn(__func__, "/Users/zaks/tmp/ex.c", 24, "x && y") : (void)0);
819   strcmp(x, y); // no warning
820 }
821 
radar_11358224_test_double_assign_ints_positive_2()822 void radar_11358224_test_double_assign_ints_positive_2()
823 {
824   void *ptr = malloc(16);
825   ptr = ptr;
826 } // expected-warning {{leak}}
827 
828 // Assume that functions which take a function pointer can free memory even if
829 // they are defined in system headers and take the const pointer to the
830 // allocated memory. (radar://11160612)
831 int const_ptr_and_callback(int, const char*, int n, void(*)(void*));
r11160612_1()832 void r11160612_1() {
833   char *x = malloc(12);
834   const_ptr_and_callback(0, x, 12, free); // no - warning
835 }
836 
837 // Null is passed as callback.
r11160612_2()838 void r11160612_2() {
839   char *x = malloc(12);
840   const_ptr_and_callback(0, x, 12, 0);
841 } // expected-warning {{leak}}
842 
843 // Callback is passed to a function defined in a system header.
r11160612_4()844 void r11160612_4() {
845   char *x = malloc(12);
846   sqlite3_bind_text_my(0, x, 12, free); // no - warning
847 }
848 
849 // Passing callbacks in a struct.
r11160612_5(StWithCallback St)850 void r11160612_5(StWithCallback St) {
851   void *x = malloc(12);
852   dealocateMemWhenDoneByVal(x, St);
853 }
r11160612_6(StWithCallback St)854 void r11160612_6(StWithCallback St) {
855   void *x = malloc(12);
856   dealocateMemWhenDoneByRef(&St, x);
857 }
858 
859 int mySub(int, int);
860 int myAdd(int, int);
fPtr(unsigned cond,int x)861 int fPtr(unsigned cond, int x) {
862   return (cond ? mySub : myAdd)(x, x);
863 }
864 
865 // Test anti-aliasing.
866 
dependsOnValueOfPtr(int * g,unsigned f)867 void dependsOnValueOfPtr(int *g, unsigned f) {
868   int *p;
869 
870   if (f) {
871     p = g;
872   } else {
873     p = malloc(12);
874   }
875 
876   if (p != g)
877     free(p);
878   else
879     return; // no warning
880   return;
881 }
882 
CMPRegionHeapToStack()883 int CMPRegionHeapToStack() {
884   int x = 0;
885   int *x1 = malloc(8);
886   int *x2 = &x;
887   clang_analyzer_eval(x1 == x2); // expected-warning{{FALSE}}
888   free(x1);
889   return x;
890 }
891 
CMPRegionHeapToHeap2()892 int CMPRegionHeapToHeap2() {
893   int x = 0;
894   int *x1 = malloc(8);
895   int *x2 = malloc(8);
896   int *x4 = x1;
897   int *x5 = x2;
898   clang_analyzer_eval(x4 == x5); // expected-warning{{FALSE}}
899   free(x1);
900   free(x2);
901   return x;
902 }
903 
CMPRegionHeapToHeap()904 int CMPRegionHeapToHeap() {
905   int x = 0;
906   int *x1 = malloc(8);
907   int *x4 = x1;
908   if (x1 == x4) {
909     free(x1);
910     return 5/x; // expected-warning{{Division by zero}}
911   }
912   return x;// expected-warning{{This statement is never executed}}
913 }
914 
HeapAssignment()915 int HeapAssignment() {
916   int m = 0;
917   int *x = malloc(4);
918   int *y = x;
919   *x = 5;
920   clang_analyzer_eval(*x != *y); // expected-warning{{FALSE}}
921   free(x);
922   return 0;
923 }
924 
925 int *retPtr();
926 int *retPtrMightAlias(int *x);
cmpHeapAllocationToUnknown()927 int cmpHeapAllocationToUnknown() {
928   int zero = 0;
929   int *yBefore = retPtr();
930   int *m = malloc(8);
931   int *yAfter = retPtrMightAlias(m);
932   clang_analyzer_eval(yBefore == m); // expected-warning{{FALSE}}
933   clang_analyzer_eval(yAfter == m); // expected-warning{{FALSE}}
934   free(m);
935   return 0;
936 }
937 
localArrayTest()938 void localArrayTest() {
939   char *p = (char*)malloc(12);
940   char *ArrayL[12];
941   ArrayL[0] = p;
942 } // expected-warning {{leak}}
943 
localStructTest()944 void localStructTest() {
945   StructWithPtr St;
946   StructWithPtr *pSt = &St;
947   pSt->memP = malloc(12);
948 } // expected-warning{{Potential leak of memory pointed to by}}
949 
950 #ifdef __INTPTR_TYPE__
951 // Test double assignment through integers.
952 typedef __INTPTR_TYPE__ intptr_t;
953 typedef unsigned __INTPTR_TYPE__ uintptr_t;
954 
955 static intptr_t glob;
test_double_assign_ints()956 void test_double_assign_ints()
957 {
958   void *ptr = malloc (16);  // no-warning
959   glob = (intptr_t)(uintptr_t)ptr;
960 }
961 
test_double_assign_ints_positive()962 void test_double_assign_ints_positive()
963 {
964   void *ptr = malloc(16);
965   (void*)(intptr_t)(uintptr_t)ptr; // expected-warning {{unused}}
966 } // expected-warning {{leak}}
967 #endif
968 
testCGContextNoLeak()969 void testCGContextNoLeak()
970 {
971   void *ptr = malloc(16);
972   CGContextRef context = CGBitmapContextCreate(ptr);
973 
974   // Because you can get the data back out like this, even much later,
975   // CGBitmapContextCreate is one of our "stop-tracking" exceptions.
976   free(CGBitmapContextGetData(context));
977 }
978 
testCGContextLeak()979 void testCGContextLeak()
980 {
981   void *ptr = malloc(16);
982   CGContextRef context = CGBitmapContextCreate(ptr);
983   // However, this time we're just leaking the data, because the context
984   // object doesn't escape and it hasn't been freed in this function.
985 }
986 
987 // Allow xpc context to escape. radar://11635258
988 // TODO: Would be great if we checked that the finalize_connection_context actually releases it.
finalize_connection_context(void * ctx)989 static void finalize_connection_context(void *ctx) {
990   int *context = ctx;
991   free(context);
992 }
foo(xpc_connection_t peer)993 void foo (xpc_connection_t peer) {
994   int *ctx = calloc(1, sizeof(int));
995   xpc_connection_set_context(peer, ctx);
996   xpc_connection_set_finalizer_f(peer, finalize_connection_context);
997   xpc_connection_resume(peer);
998 }
999 
1000 // Make sure we catch errors when we free in a function which does not allocate memory.
freeButNoMalloc(int * p,int x)1001 void freeButNoMalloc(int *p, int x){
1002   if (x) {
1003     free(p);
1004     //user forgot a return here.
1005   }
1006   free(p); // expected-warning {{Attempt to free released memory}}
1007 }
1008 
1009 struct HasPtr {
1010   char *p;
1011 };
1012 
reallocButNoMalloc(struct HasPtr * a,int c,int size)1013 char* reallocButNoMalloc(struct HasPtr *a, int c, int size) {
1014   int *s;
1015   char *b = realloc(a->p, size);
1016   char *m = realloc(a->p, size); // expected-warning {{Attempt to free released memory}}
1017   return a->p;
1018 }
1019 
1020 // We should not warn in this case since the caller will presumably free a->p in all cases.
reallocButNoMallocPR13674(struct HasPtr * a,int c,int size)1021 int reallocButNoMallocPR13674(struct HasPtr *a, int c, int size) {
1022   int *s;
1023   char *b = realloc(a->p, size);
1024   if (b == 0)
1025     return -1;
1026   a->p = b;
1027   return 0;
1028 }
1029 
1030 // Test realloc with no visible malloc.
test(void * ptr)1031 void *test(void *ptr) {
1032   void *newPtr = realloc(ptr, 4);
1033   if (newPtr == 0) {
1034     if (ptr)
1035       free(ptr); // no-warning
1036   }
1037   return newPtr;
1038 }
1039 
1040 
testLeakWithinReturn(char * str)1041 char *testLeakWithinReturn(char *str) {
1042   return strdup(strdup(str)); // expected-warning{{leak}}
1043 }
1044 
1045 void passConstPtr(const char * ptr);
1046 
testPassConstPointer()1047 void testPassConstPointer() {
1048   char * string = malloc(sizeof(char)*10);
1049   passConstPtr(string);
1050   return; // expected-warning {{leak}}
1051 }
1052 
testPassConstPointerIndirectly()1053 void testPassConstPointerIndirectly() {
1054   char *p = malloc(1);
1055   p++;
1056   memcmp(p, p, sizeof(&p));
1057   return; // expected-warning {{leak}}
1058 }
1059 
testPassConstPointerIndirectlyStruct()1060 void testPassConstPointerIndirectlyStruct() {
1061   struct HasPtr hp;
1062   hp.p = malloc(10);
1063   memcmp(&hp, &hp, sizeof(hp));
1064   return; // expected-warning {{Potential leak of memory pointed to by 'hp.p'}}
1065 }
1066 
testPassToSystemHeaderFunctionIndirectlyStruct()1067 void testPassToSystemHeaderFunctionIndirectlyStruct() {
1068   SomeStruct ss;
1069   ss.p = malloc(1);
1070   fakeSystemHeaderCall(&ss); // invalidates ss, making ss.p unreachable
1071   // Technically a false negative here -- we know the system function won't free
1072   // ss.p, but nothing else will either!
1073 } // no-warning
1074 
testPassToSystemHeaderFunctionIndirectlyStructFree()1075 void testPassToSystemHeaderFunctionIndirectlyStructFree() {
1076   SomeStruct ss;
1077   ss.p = malloc(1);
1078   fakeSystemHeaderCall(&ss); // invalidates ss, making ss.p unreachable
1079   free(ss.p);
1080 } // no-warning
1081 
testPassToSystemHeaderFunctionIndirectlyArray()1082 void testPassToSystemHeaderFunctionIndirectlyArray() {
1083   int *p[1];
1084   p[0] = malloc(sizeof(int));
1085   fakeSystemHeaderCallIntPtr(p); // invalidates p, making p[0] unreachable
1086   // Technically a false negative here -- we know the system function won't free
1087   // p[0], but nothing else will either!
1088 } // no-warning
1089 
testPassToSystemHeaderFunctionIndirectlyArrayFree()1090 void testPassToSystemHeaderFunctionIndirectlyArrayFree() {
1091   int *p[1];
1092   p[0] = malloc(sizeof(int));
1093   fakeSystemHeaderCallIntPtr(p); // invalidates p, making p[0] unreachable
1094   free(p[0]);
1095 } // no-warning
1096 
testOffsetAllocate(size_t size)1097 int *testOffsetAllocate(size_t size) {
1098   int *memoryBlock = (int *)malloc(size + sizeof(int));
1099   return &memoryBlock[1]; // no-warning
1100 }
1101 
testOffsetDeallocate(int * memoryBlock)1102 void testOffsetDeallocate(int *memoryBlock) {
1103   free(&memoryBlock[-1]);  // no-warning
1104 }
1105 
testOffsetOfRegionFreed()1106 void testOffsetOfRegionFreed() {
1107   __int64_t * array = malloc(sizeof(__int64_t)*2);
1108   array += 1;
1109   free(&array[0]); // expected-warning{{Argument to free() is offset by 8 bytes from the start of memory allocated by malloc()}}
1110 }
1111 
testOffsetOfRegionFreed2()1112 void testOffsetOfRegionFreed2() {
1113   __int64_t *p = malloc(sizeof(__int64_t)*2);
1114   p += 1;
1115   free(p); // expected-warning{{Argument to free() is offset by 8 bytes from the start of memory allocated by malloc()}}
1116 }
1117 
testOffsetOfRegionFreed3()1118 void testOffsetOfRegionFreed3() {
1119   char *r = malloc(sizeof(char));
1120   r = r - 10;
1121   free(r); // expected-warning {{Argument to free() is offset by -10 bytes from the start of memory allocated by malloc()}}
1122 }
1123 
testOffsetOfRegionFreedAfterFunctionCall()1124 void testOffsetOfRegionFreedAfterFunctionCall() {
1125   int *p = malloc(sizeof(int)*2);
1126   p += 1;
1127   myfoo(p);
1128   free(p); // expected-warning{{Argument to free() is offset by 4 bytes from the start of memory allocated by malloc()}}
1129 }
1130 
testFixManipulatedPointerBeforeFree()1131 void testFixManipulatedPointerBeforeFree() {
1132   int * array = malloc(sizeof(int)*2);
1133   array += 1;
1134   free(&array[-1]); // no-warning
1135 }
1136 
testFixManipulatedPointerBeforeFree2()1137 void testFixManipulatedPointerBeforeFree2() {
1138   char *r = malloc(sizeof(char));
1139   r = r + 10;
1140   free(r-10); // no-warning
1141 }
1142 
freeOffsetPointerPassedToFunction()1143 void freeOffsetPointerPassedToFunction() {
1144   __int64_t *p = malloc(sizeof(__int64_t)*2);
1145   p[1] = 0;
1146   p += 1;
1147   myfooint(*p); // not passing the pointer, only a value pointed by pointer
1148   free(p); // expected-warning {{Argument to free() is offset by 8 bytes from the start of memory allocated by malloc()}}
1149 }
1150 
1151 int arbitraryInt();
freeUnknownOffsetPointer()1152 void freeUnknownOffsetPointer() {
1153   char *r = malloc(sizeof(char));
1154   r = r + arbitraryInt(); // unable to reason about what the offset might be
1155   free(r); // no-warning
1156 }
1157 
testFreeNonMallocPointerWithNoOffset()1158 void testFreeNonMallocPointerWithNoOffset() {
1159   char c;
1160   char *r = &c;
1161   r = r + 10;
1162   free(r-10); // expected-warning {{Argument to free() is the address of the local variable 'c', which is not memory allocated by malloc()}}
1163 }
1164 
testFreeNonMallocPointerWithOffset()1165 void testFreeNonMallocPointerWithOffset() {
1166   char c;
1167   char *r = &c;
1168   free(r+1); // expected-warning {{Argument to free() is the address of the local variable 'c', which is not memory allocated by malloc()}}
1169 }
1170 
testOffsetZeroDoubleFree()1171 void testOffsetZeroDoubleFree() {
1172   int *array = malloc(sizeof(int)*2);
1173   int *p = &array[0];
1174   free(p);
1175   free(&array[0]); // expected-warning{{Attempt to free released memory}}
1176 }
1177 
testOffsetPassedToStrlen()1178 void testOffsetPassedToStrlen() {
1179   char * string = malloc(sizeof(char)*10);
1180   string += 1;
1181   int length = strlen(string); // expected-warning {{Potential leak of memory pointed to by 'string'}}
1182 }
1183 
testOffsetPassedToStrlenThenFree()1184 void testOffsetPassedToStrlenThenFree() {
1185   char * string = malloc(sizeof(char)*10);
1186   string += 1;
1187   int length = strlen(string);
1188   free(string); // expected-warning {{Argument to free() is offset by 1 byte from the start of memory allocated by malloc()}}
1189 }
1190 
testOffsetPassedAsConst()1191 void testOffsetPassedAsConst() {
1192   char * string = malloc(sizeof(char)*10);
1193   string += 1;
1194   passConstPtr(string);
1195   free(string); // expected-warning {{Argument to free() is offset by 1 byte from the start of memory allocated by malloc()}}
1196 }
1197 
1198 char **_vectorSegments;
1199 int _nVectorSegments;
1200 
poolFreeC(void * s)1201 void poolFreeC(void* s) {
1202   free(s); // no-warning
1203 }
freeMemory()1204 void freeMemory() {
1205   while (_nVectorSegments) {
1206     poolFreeC(_vectorSegments[_nVectorSegments++]);
1207   }
1208 }
1209 
1210 // ----------------------------------------------------------------------------
1211 // False negatives.
1212 
testMallocWithParam(int ** p)1213 void testMallocWithParam(int **p) {
1214   *p = (int*) malloc(sizeof(int));
1215   *p = 0; // FIXME: should warn here
1216 }
1217 
testMallocWithParam_2(int ** p)1218 void testMallocWithParam_2(int **p) {
1219   *p = (int*) malloc(sizeof(int)); // no-warning
1220 }
1221 
testPassToSystemHeaderFunctionIndirectly()1222 void testPassToSystemHeaderFunctionIndirectly() {
1223   int *p = malloc(4);
1224   p++;
1225   fakeSystemHeaderCallInt(p);
1226   // FIXME: This is a leak: if we think a system function won't free p, it
1227   // won't free (p-1) either.
1228 }
1229