[analyzer] Match more patterns in bugreporter::getDerefExpr() API.
This function can now track null pointer through simple pointer arithmetic,
such as '*&*(p + 2)' => 'p' and so on, displaying intermediate diagnostic pieces
for the user to understand where the null pointer is coming from.
Differential Revision: https://reviews.llvm.org/D37025
llvm-svn: 314290
diff --git a/clang/test/Analysis/nullptr.cpp b/clang/test/Analysis/nullptr.cpp
index 229ad7b..b3e61c9 100644
--- a/clang/test/Analysis/nullptr.cpp
+++ b/clang/test/Analysis/nullptr.cpp
@@ -1,11 +1,12 @@
-// RUN: %clang_analyze_cc1 -std=c++11 -Wno-conversion-null -analyzer-checker=core,debug.ExprInspection -analyzer-store region -verify %s
+// RUN: %clang_analyze_cc1 -std=c++11 -Wno-conversion-null -analyzer-checker=core,debug.ExprInspection -analyzer-store region -analyzer-output=text -verify %s
void clang_analyzer_eval(int);
// test to see if nullptr is detected as a null pointer
void foo1(void) {
- char *np = nullptr;
+ char *np = nullptr; // expected-note{{'np' initialized to a null pointer value}}
*np = 0; // expected-warning{{Dereference of null pointer}}
+ // expected-note@-1{{Dereference of null pointer}}
}
// check if comparing nullptr to nullptr is detected properly
@@ -23,10 +24,11 @@
struct foo {
int a, f;
};
- char *np = nullptr;
+ char *np = nullptr; // expected-note{{'np' initialized to a null pointer value}}
// casting a nullptr to anything should be caught eventually
- int *ip = &(((struct foo *)np)->f);
+ int *ip = &(((struct foo *)np)->f); // expected-note{{'ip' initialized to a null pointer value}}
*ip = 0; // expected-warning{{Dereference of null pointer}}
+ // expected-note@-1{{Dereference of null pointer}}
// should be error here too, but analysis gets stopped
// *np = 0;
}
@@ -49,16 +51,31 @@
}
void zoo1() {
- char **p = 0;
+ char **p = 0; // expected-note{{'p' initialized to a null pointer value}}
delete *(p + 0); // expected-warning{{Dereference of null pointer}}
+ // expected-note@-1{{Dereference of null pointer}}
+}
+
+void zoo1backwards() {
+ char **p = 0; // expected-note{{'p' initialized to a null pointer value}}
+ delete *(0 + p); // expected-warning{{Dereference of null pointer}}
+ // expected-note@-1{{Dereference of null pointer}}
+}
+
+typedef __INTPTR_TYPE__ intptr_t;
+void zoo1multiply() {
+ char **p = 0; // FIXME-should-be-note:{{'p' initialized to a null pointer value}}
+ delete *((char **)((intptr_t)p * 2)); // expected-warning{{Dereference of null pointer}}
+ // expected-note@-1{{Dereference of null pointer}}
}
void zoo2() {
int **a = 0;
- int **b = 0;
+ int **b = 0; // expected-note{{'b' initialized to a null pointer value}}
asm ("nop"
:"=r"(*a)
:"0"(*b) // expected-warning{{Dereference of null pointer}}
+ // expected-note@-1{{Dereference of null pointer}}
);
}
@@ -70,17 +87,19 @@
int a;
};
- int *x = 0;
+ int *x = 0; // expected-note{{'x' initialized to a null pointer value}}
return S(*x).a; // expected-warning{{Dereference of null pointer}}
+ // expected-note@-1{{Dereference of null pointer}}
}
int materializeTempExpr() {
- int *n = 0;
+ int *n = 0; // expected-note{{'n' initialized to a null pointer value}}
struct S {
int a;
S(int i): a(i) {}
};
const S &s = S(*n); // expected-warning{{Dereference of null pointer}}
+ // expected-note@-1{{Dereference of null pointer}}
return s.a;
}
@@ -98,6 +117,7 @@
void invokeF(X* x) {
x->f(); // expected-warning{{Called C++ object pointer is null}}
+ // expected-note@-1{{Called C++ object pointer is null}}
}
struct Type {
@@ -105,26 +125,41 @@
};
void shouldNotCrash() {
- decltype(nullptr) p;
- if (getSymbol())
- invokeF(p); // expected-warning{{1st function call argument is an uninit}}
- if (getSymbol())
- invokeF(nullptr);
- if (getSymbol()) {
- X *x = Type().x;
+ decltype(nullptr) p; // expected-note{{'p' declared without an initial value}}
+ if (getSymbol()) // expected-note {{Assuming the condition is false}}
+ // expected-note@-1{{Taking false branch}}
+ // expected-note@-2{{Assuming the condition is false}}
+ // expected-note@-3{{Taking false branch}}
+ // expected-note@-4{{Assuming the condition is true}}
+ // expected-note@-5{{Taking true branch}}
+ invokeF(p); // expected-warning{{1st function call argument is an uninitialized value}}
+ // expected-note@-1{{1st function call argument is an uninitialized value}}
+ if (getSymbol()) // expected-note {{Assuming the condition is false}}
+ // expected-note@-1{{Taking false branch}}
+ // expected-note@-2{{Assuming the condition is true}}
+ // expected-note@-3{{Taking true branch}}
+ invokeF(nullptr); // expected-note {{Calling 'invokeF'}}
+ // expected-note@-1{{Passing null pointer value via 1st parameter 'x'}}
+ if (getSymbol()) { // expected-note {{Assuming the condition is true}}
+ // expected-note@-1{{Taking true branch}}
+ X *x = Type().x; // expected-note{{'x' initialized to a null pointer value}}
x->f(); // expected-warning{{Called C++ object pointer is null}}
+ // expected-note@-1{{Called C++ object pointer is null}}
}
}
void f(decltype(nullptr) p) {
int *q = nullptr;
clang_analyzer_eval(p == 0); // expected-warning{{TRUE}}
+ // expected-note@-1{{TRUE}}
clang_analyzer_eval(q == 0); // expected-warning{{TRUE}}
+ // expected-note@-1{{TRUE}}
}
decltype(nullptr) returnsNullPtrType();
void fromReturnType() {
((X *)returnsNullPtrType())->f(); // expected-warning{{Called C++ object pointer is null}}
+ // expected-note@-1{{Called C++ object pointer is null}}
}
#define AS_ATTRIBUTE __attribute__((address_space(256)))