2018-03-31 03:27:42 +08:00
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// RUN: %clang_analyze_cc1 -w -x c -analyzer-checker=core,unix -analyzer-output=text -verify %s
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2017-09-27 17:33:37 +08:00
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// Avoid the crash when finding the expression for tracking the origins
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2017-09-27 18:59:06 +08:00
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// of the null pointer for path notes.
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2017-09-27 17:33:37 +08:00
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void pr34373() {
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2017-09-27 17:50:45 +08:00
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int *a = 0; // expected-note{{'a' initialized to a null pointer value}}
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2017-09-27 17:33:37 +08:00
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(a + 0)[0]; // expected-warning{{Array access results in a null pointer dereference}}
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// expected-note@-1{{Array access results in a null pointer dereference}}
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}
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2018-03-31 03:27:42 +08:00
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typedef __typeof(sizeof(int)) size_t;
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void *memcpy(void *dest, const void *src, unsigned long count);
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void f1(char *source) {
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char *destination = 0; // expected-note{{'destination' initialized to a null pointer value}}
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memcpy(destination + 0, source, 10); // expected-warning{{Null pointer argument in call to memory copy function}}
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// expected-note@-1{{Null pointer argument in call to memory copy function}}
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}
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void f2(char *source) {
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char *destination = 0; // expected-note{{'destination' initialized to a null pointer value}}
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memcpy(destination - 0, source, 10); // expected-warning{{Null pointer argument in call to memory copy function}}
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// expected-note@-1{{Null pointer argument in call to memory copy function}}
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}
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void f3(char *source) {
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[analyzer] Do not run visitors until the fixpoint, run only once.
In the current implementation, we run visitors until the fixed point is
reached.
That is, if a visitor adds another visitor, the currently processed path
is destroyed, all diagnostics is discarded, and it is regenerated again,
until it's no longer modified.
This pattern has a few negative implications:
- This loop does not even guarantee to terminate.
E.g. just imagine two visitors bouncing a diagnostics around.
- Performance-wise, e.g. for sqlite3 all visitors are being re-run at
least 10 times for some bugs.
We have already seen a few reports where it leads to timeouts.
- If we want to add more computationally intense visitors, this will
become worse.
- From architectural standpoint, the current layout requires copying
visitors, which is conceptually wrong, and can be annoying (e.g. no
unique_ptr on visitors allowed).
The proposed change is a much simpler architecture: the outer loop
processes nodes upwards, and whenever the visitor is added it only
processes current nodes and above, thus guaranteeing termination.
Differential Revision: https://reviews.llvm.org/D47856
llvm-svn: 335666
2018-06-27 05:12:08 +08:00
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char *destination = 0; // expected-note{{'destination' initialized to a null pointer value}}
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2018-03-31 03:27:42 +08:00
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destination = destination + 0; // expected-note{{Null pointer value stored to 'destination'}}
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memcpy(destination, source, 10); // expected-warning{{Null pointer argument in call to memory copy function}}
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// expected-note@-1{{Null pointer argument in call to memory copy function}}
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}
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void f4(char *source) {
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[analyzer] Do not run visitors until the fixpoint, run only once.
In the current implementation, we run visitors until the fixed point is
reached.
That is, if a visitor adds another visitor, the currently processed path
is destroyed, all diagnostics is discarded, and it is regenerated again,
until it's no longer modified.
This pattern has a few negative implications:
- This loop does not even guarantee to terminate.
E.g. just imagine two visitors bouncing a diagnostics around.
- Performance-wise, e.g. for sqlite3 all visitors are being re-run at
least 10 times for some bugs.
We have already seen a few reports where it leads to timeouts.
- If we want to add more computationally intense visitors, this will
become worse.
- From architectural standpoint, the current layout requires copying
visitors, which is conceptually wrong, and can be annoying (e.g. no
unique_ptr on visitors allowed).
The proposed change is a much simpler architecture: the outer loop
processes nodes upwards, and whenever the visitor is added it only
processes current nodes and above, thus guaranteeing termination.
Differential Revision: https://reviews.llvm.org/D47856
llvm-svn: 335666
2018-06-27 05:12:08 +08:00
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char *destination = 0; // expected-note{{'destination' initialized to a null pointer value}}
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2018-03-31 03:27:42 +08:00
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destination = destination - 0; // expected-note{{Null pointer value stored to 'destination'}}
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memcpy(destination, source, 10); // expected-warning{{Null pointer argument in call to memory copy function}}
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// expected-note@-1{{Null pointer argument in call to memory copy function}}
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}
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void f5(char *source) {
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char *destination1 = 0; // expected-note{{'destination1' initialized to a null pointer value}}
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char *destination2 = destination1 + 0; // expected-note{{'destination2' initialized to a null pointer value}}
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memcpy(destination2, source, 10); // expected-warning{{Null pointer argument in call to memory copy function}}
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// expected-note@-1{{Null pointer argument in call to memory copy function}}
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}
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void f6(char *source) {
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char *destination1 = 0; // expected-note{{'destination1' initialized to a null pointer value}}
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char *destination2 = destination1 - 0; // expected-note{{'destination2' initialized to a null pointer value}}
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memcpy(destination2, source, 10); // expected-warning{{Null pointer argument in call to memory copy function}}
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// expected-note@-1{{Null pointer argument in call to memory copy function}}
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}
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