xref: /llvm-project/clang/test/Analysis/misc-ps-eager-assume.m (revision 0f1c1be1968076d6f96f8a7bcc4a15cf195ecd97)
1// RUN: %clang_analyze_cc1 -analyzer-checker=core,alpha.core -verify -fblocks %s
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// In this test case, 'needsAnArray' is a signed char.  The analyzer tracks
47// a symbolic value for this variable, but in the branch condition it is
48// promoted to 'int'.  Currently the analyzer doesn't reason well about
49// promotions of symbolic values, so this test case tests the logic in
50// 'recoverCastedSymbol()' (ExprEngine.cpp) to test that we recover
51// path-sensitivity and use the symbol for 'needsAnArray' in the branch
52// condition.
53//
54void handle_symbolic_cast_in_condition(void) {
55  NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
56
57  BOOL needsAnArray = [@"aString" isEqualToString:@"anotherString"];
58  NSMutableArray* array = needsAnArray ? [[NSMutableArray alloc] init] : 0;
59  if(needsAnArray)
60    [array release];
61
62  [pool drain];
63}
64
65// From PR 3836 (http://llvm.org/bugs/show_bug.cgi?id=3836)
66//
67// In this test case, the double '!' works fine with our symbolic constraints,
68// but we don't support comparing SymConstraint != SymConstraint.  By eagerly
69// assuming the truth of !!a or !!b, we can compare these values directly.
70//
71void pr3836(int *a, int *b) {
72  if (!!a != !!b) /* one of them is NULL */
73    return;
74  if (!a && !b) /* both are NULL */
75    return;
76
77  *a = 1; // no-warning
78  *b = 1; // no-warning
79}
80
81
82//===---------------------------------------------------------------------===//
83// This false positive occurred because the symbolic constraint on a short was
84// not maintained via sign extension.  The analyzer doesn't properly handle
85// the sign extension, but now tracks the constraint.  This particular
86// case relies on -analyzer-options eagerly-assume=true because of the expression
87// 'Flag1 != Count > 0'.
88//===---------------------------------------------------------------------===//
89
90void rdar7342806_aux(short x);
91
92void rdar7342806(void) {
93  extern short Count;
94  extern short Flag1;
95
96  short *Pointer = 0;
97  short  Flag2   = !!Pointer;   // Flag2 is false (0).
98  short  Ok      = 1;
99  short  Which;
100
101  if( Flag1 != Count > 0 )
102    // Static analyzer skips this so either
103    //   Flag1 is true and Count > 0
104    // or
105    //   Flag1 is false and Count <= 0
106    Ok = 0;
107
108  if( Flag1 != Flag2 )
109    // Analyzer skips this so Flag1 and Flag2 have the
110    // same value, both are false because Flag2 is false. And
111    // from that we know Count must be <= 0.
112    Ok = 0;
113
114  for( Which = 0;
115         Which < Count && Ok;
116           Which++ )
117    // This statement can only execute if Count > 0 which can only
118    // happen when Flag1 and Flag2 are both true and Flag2 will only
119    // be true when Pointer is not NULL.
120    rdar7342806_aux(*Pointer); // no-warning
121}
122
123//===---------------------------------------------------------------------===//
124// PR 5627 - http://llvm.org/bugs/show_bug.cgi?id=5627
125//  This test case depends on using -analyzer-config eagerly-assume=true.
126//  The 'eagerly-assume=true' causes the path
127//  to bifurcate when evaluating the function call argument, and a state
128//  caching bug in ExprEngine::CheckerVisit (and friends) caused the store
129//  to 'p' to not be evaluated along one path, but then an autotransition caused
130//  the path to keep on propagating with 'p' still set to an undefined value.
131//  We would then get a bogus report of returning uninitialized memory.
132//  Note: CheckerVisit mistakenly cleared an existing node, and the cleared
133//  node was resurrected by GRStmtNodeBuilder::~GRStmtNodeBuilder(), where
134//  'p' was not assigned.
135//===---------------------------------------------------------------------===//
136
137float *pr5627_f(int y);
138
139float *pr5627_g(int x) {
140  float *p;
141  p = pr5627_f(!x);
142  return p; // no-warning
143}
144
145