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[analyzer] Treat more const variables and fields as known contants.
When loading from a variable or a field that is declared as constant, the analyzer will try to inspect its initializer and constant-fold it. Upon success, the analyzer would skip normal load and return the respective constant. The new behavior also applies to fields/elements of brace-initialized structures and arrays. Patch by Rafael Stahl! Differential Revision: https://reviews.llvm.org/D45774 llvm-svn: 331556
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// RUN: %clang_analyze_cc1 -analyzer-checker=core -verify %s | ||
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static const unsigned long long scull = 0; | ||
void static_int() | ||
{ | ||
*(int*)scull = 0; // expected-warning{{Dereference of null pointer}} | ||
} | ||
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const unsigned long long cull = 0; | ||
void const_int() | ||
{ | ||
*(int*)cull = 0; // expected-warning{{Dereference of null pointer}} | ||
} | ||
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static int * const spc = 0; | ||
void static_ptr() | ||
{ | ||
*spc = 0; // expected-warning{{Dereference of null pointer}} | ||
} | ||
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int * const pc = 0; | ||
void const_ptr() | ||
{ | ||
*pc = 0; // expected-warning{{Dereference of null pointer}} | ||
} | ||
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const unsigned long long cull_nonnull = 4; | ||
void nonnull_int() | ||
{ | ||
*(int*)(cull_nonnull - 4) = 0; // expected-warning{{Dereference of null pointer}} | ||
} | ||
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int * const pc_nonnull = (int*)sizeof(int); | ||
void nonnull_ptr() | ||
{ | ||
*(pc_nonnull - 1) = 0; // expected-warning{{Dereference of null pointer}} | ||
} | ||
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int * const constcast = const_cast<int * const>((int*)sizeof(int)); | ||
void cast1() | ||
{ | ||
*(constcast - 1) = 0; // expected-warning{{Dereference of null pointer}} | ||
} | ||
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int * const recast = reinterpret_cast<int*>(sizeof(int)); | ||
void cast2() | ||
{ | ||
*(recast - 1) = 0; // expected-warning{{Dereference of null pointer}} | ||
} | ||
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int * const staticcast = static_cast<int * const>((int*)sizeof(int)); | ||
void cast3() | ||
{ | ||
*(staticcast - 1) = 0; // expected-warning{{Dereference of null pointer}} | ||
} | ||
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struct Foo { int a; }; | ||
Foo * const dyncast = dynamic_cast<Foo * const>((Foo*)sizeof(Foo)); | ||
void cast4() | ||
{ | ||
// Do not handle dynamic_cast for now, because it may change the pointer value. | ||
(dyncast - 1)->a = 0; // no-warning | ||
} | ||
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typedef int * const intptrconst; | ||
int * const funccast = intptrconst(sizeof(int)); | ||
void cast5() | ||
{ | ||
*(funccast - 1) = 0; // expected-warning{{Dereference of null pointer}} | ||
} | ||
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struct S1 | ||
{ | ||
int * p; | ||
}; | ||
const S1 s1 = { | ||
.p = (int*)sizeof(int) | ||
}; | ||
void conststruct() | ||
{ | ||
*(s1.p - 1) = 0; // expected-warning{{Dereference of null pointer}} | ||
} | ||
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struct S2 | ||
{ | ||
int * const p; | ||
}; | ||
S2 s2 = { | ||
.p = (int*)sizeof(int) | ||
}; | ||
void constfield() | ||
{ | ||
*(s2.p - 1) = 0; // expected-warning{{Dereference of null pointer}} | ||
} | ||
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int * const parr[1] = { (int*)sizeof(int) }; | ||
void constarr() | ||
{ | ||
*(parr[0] - 1) = 0; // expected-warning{{Dereference of null pointer}} | ||
} | ||
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struct S3 | ||
{ | ||
int * p = (int*)sizeof(int); | ||
}; | ||
void recordinit() | ||
{ | ||
S3 s3; | ||
*(s3.p - 1) = 0; // expected-warning{{Dereference of null pointer}} | ||
} |