1// RUN: %clang_cc1 -analyze -analyzer-checker=core,alpha.core -analyzer-store=region -analyzer-constraints=range -verify -fblocks %s -analyzer-eagerly-assume
2// expected-no-diagnostics
3
4// Delta-reduced header stuff (needed for test cases).
5typedef signed char BOOL;
6typedef unsigned int NSUInteger;
7typedef struct _NSZone NSZone;
8@class NSInvocation, NSMethodSignature, NSCoder, NSString, NSEnumerator;
9@protocol NSObject  - (BOOL)isEqual:(id)object;
10- (oneway void)release;
11@end  @protocol NSCopying  - (id)copyWithZone:(NSZone *)zone;
12@end  @protocol NSMutableCopying  - (id)mutableCopyWithZone:(NSZone *)zone;
13@end  @protocol NSCoding  - (void)encodeWithCoder:(NSCoder *)aCoder;
14@end    @interface NSObject <NSObject> {}
15+ (id)alloc;
16- (id)init;
17@end  typedef struct {}
18NSFastEnumerationState;
19@protocol NSFastEnumeration  - (NSUInteger)countByEnumeratingWithState:(NSFastEnumerationState *)state objects:(id *)stackbuf count:(NSUInteger)len;
20@end      @interface NSArray : NSObject <NSCopying, NSMutableCopying, NSCoding, NSFastEnumeration>  - (NSUInteger)count;
21@end    @interface NSMutableArray : NSArray  - (void)addObject:(id)anObject;
22- (BOOL)isEqualToString:(NSString *)aString;
23@end        @interface NSAutoreleasePool : NSObject {}
24- (void)drain;
25- (id)init;
26@end
27
28// This test case tests that (x != 0) is eagerly evaluated before stored to
29// 'y'.  This test case complements recoverCastedSymbol (see below) because
30// the symbolic expression is stored to 'y' (which is a short instead of an
31// int).  recoverCastedSymbol() only recovers path-sensitivity when the
32// symbolic expression is literally the branch condition.
33//
34void handle_assign_of_condition(int x) {
35  // The cast to 'short' causes us to lose symbolic constraint.
36  short y = (x != 0);
37  char *p = 0;
38  if (y) {
39    // This should be infeasible.
40    if (!(x != 0)) {
41      *p = 1;  // no-warning
42    }
43  }
44}
45
46// From <rdar://problem/6619921>
47//
48// In this test case, 'needsAnArray' is a signed char.  The analyzer tracks
49// a symbolic value for this variable, but in the branch condition it is
50// promoted to 'int'.  Currently the analyzer doesn't reason well about
51// promotions of symbolic values, so this test case tests the logic in
52// 'recoverCastedSymbol()' (GRExprEngine.cpp) to test that we recover
53// path-sensitivity and use the symbol for 'needsAnArray' in the branch
54// condition.
55//
56void handle_symbolic_cast_in_condition(void) {
57  NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
58
59  BOOL needsAnArray = [@"aString" isEqualToString:@"anotherString"];
60  NSMutableArray* array = needsAnArray ? [[NSMutableArray alloc] init] : 0;
61  if(needsAnArray)
62    [array release];
63
64  [pool drain];
65}
66
67// From PR 3836 (http://llvm.org/bugs/show_bug.cgi?id=3836)
68//
69// In this test case, the double '!' works fine with our symbolic constraints,
70// but we don't support comparing SymConstraint != SymConstraint.  By eagerly
71// assuming the truth of !!a or !!b, we can compare these values directly.
72//
73void pr3836(int *a, int *b) {
74  if (!!a != !!b) /* one of them is NULL */
75    return;
76  if (!a && !b) /* both are NULL */
77    return;
78      
79  *a = 1; // no-warning
80  *b = 1; // no-warning
81}
82
83
84//===---------------------------------------------------------------------===//
85// <rdar://problem/7342806>
86// This false positive occurred because the symbolic constraint on a short was
87// not maintained via sign extension.  The analyzer doesn't properly handle
88// the sign extension, but now tracks the constraint.  This particular
89// case relies on -analyzer-eagerly-assume because of the expression
90// 'Flag1 != Count > 0'.
91//===---------------------------------------------------------------------===//
92
93void rdar7342806_aux(short x);
94
95void rdar7342806() {
96  extern short Count;
97  extern short Flag1;
98
99  short *Pointer = 0;
100  short  Flag2   = !!Pointer;   // Flag2 is false (0).
101  short  Ok      = 1;
102  short  Which;
103
104  if( Flag1 != Count > 0 )
105    // Static analyzer skips this so either
106    //   Flag1 is true and Count > 0
107    // or
108    //   Flag1 is false and Count <= 0
109    Ok = 0;
110
111  if( Flag1 != Flag2 )
112    // Analyzer skips this so Flag1 and Flag2 have the
113    // same value, both are false because Flag2 is false. And
114    // from that we know Count must be <= 0.
115    Ok = 0;
116
117  for( Which = 0;
118         Which < Count && Ok;
119           Which++ )
120    // This statement can only execute if Count > 0 which can only
121    // happen when Flag1 and Flag2 are both true and Flag2 will only
122    // be true when Pointer is not NULL.
123    rdar7342806_aux(*Pointer); // no-warning
124}
125
126//===---------------------------------------------------------------------===//
127// PR 5627 - http://llvm.org/bugs/show_bug.cgi?id=5627
128//  This test case depends on using -analyzer-eagerly-assume and
129//  -analyzer-store=region.  The '-analyzer-eagerly-assume' causes the path
130//  to bifurcate when evaluating the function call argument, and a state
131//  caching bug in GRExprEngine::CheckerVisit (and friends) caused the store
132//  to 'p' to not be evaluated along one path, but then an autotransition caused
133//  the path to keep on propagating with 'p' still set to an undefined value.
134//  We would then get a bogus report of returning uninitialized memory.
135//  Note: CheckerVisit mistakenly cleared an existing node, and the cleared
136//  node was resurrected by GRStmtNodeBuilder::~GRStmtNodeBuilder(), where
137//  'p' was not assigned.
138//===---------------------------------------------------------------------===//
139
140float *pr5627_f(int y);
141
142float *pr5627_g(int x) {
143  float *p;
144  p = pr5627_f(!x);
145  return p; // no-warning
146}
147
148