microsoft
/
clang-1
зеркало из https://github.com/microsoft/clang-1.git
1
0
Форкнуть 0
Код Задачи Пакеты Проекты Релизы Вики Активность

Tweak null dereference diagnostics to give clearer diagnostics when 

a null dereference results from a field access.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@99236 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Ted Kremenek 2010-03-23 01:11:38 +00:00
Родитель d064fdc4b7
Коммит 452b84ded7
4 изменённых файлов: 61 добавлений и 40 удалений
Показать статистику Скачать Patch файл Скачать Diff файл Показать все файлы Свернуть все файлы

55
lib/Checker/DereferenceChecker.cpp
Просмотреть файл

@ -29,9 +29,9 @@ public:
DereferenceChecker() : BT_null(0), BT_undef(0) {}
static void *getTag() { static int tag = 0; return &tag; }
void VisitLocation(CheckerContext &C, const Stmt *S, SVal location);
std::pair<ExplodedNode * const*, ExplodedNode * const*>
getImplicitNodes() const {
getImplicitNodes() const {
return std::make_pair(ImplicitNullDerefNodes.data(),
ImplicitNullDerefNodes.data() +
ImplicitNullDerefNodes.size());
@ -59,7 +59,7 @@ void DereferenceChecker::VisitLocation(CheckerContext &C, const Stmt *S,
if (ExplodedNode *N = C.GenerateSink()) {
if (!BT_undef)
BT_undef = new BuiltinBug("Dereference of undefined pointer value");
EnhancedBugReport *report =
new EnhancedBugReport(*BT_undef, BT_undef->getDescription(), N);
report->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue,
@ -68,31 +68,32 @@ void DereferenceChecker::VisitLocation(CheckerContext &C, const Stmt *S,
}
return;
}
DefinedOrUnknownSVal location = cast<DefinedOrUnknownSVal>(l);
// Check for null dereferences.
// Check for null dereferences.
if (!isa<Loc>(location))
return;
const GRState *state = C.getState();
const GRState *notNullState, *nullState;
llvm::tie(notNullState, nullState) = state->Assume(location);
// The explicit NULL case.
if (nullState) {
if (!notNullState) {
if (!notNullState) {
// Generate an error node.
ExplodedNode *N = C.GenerateSink(nullState);
if (!N)
return;
// We know that 'location' cannot be non-null. This is what
// we call an "explicit" null dereference.
// we call an "explicit" null dereference.
if (!BT_null)
BT_null = new BuiltinBug("Dereference of null pointer");
llvm::SmallString<100> buf;
llvm::SmallVector<SourceRange, 2> Ranges;
switch (S->getStmtClass()) {
case Stmt::UnaryOperatorClass: {
@ -101,10 +102,26 @@ void DereferenceChecker::VisitLocation(CheckerContext &C, const Stmt *S,
if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(SU)) {
if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) {
llvm::raw_svector_ostream os(buf);
os << "Dereference of null pointer loaded from variable '"
<< VD->getName() << '\'';
os << "Dereference of null pointer (loaded from variable '"
<< VD->getName() << "')";
Ranges.push_back(DR->getSourceRange());
}
}
break;
}
case Stmt::MemberExprClass: {
const MemberExpr *M = cast<MemberExpr>(S);
if (M->isArrow())
if (DeclRefExpr *DR =
dyn_cast<DeclRefExpr>(M->getBase()->IgnoreParenCasts())) {
if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) {
llvm::raw_svector_ostream os(buf);
os << "Field access results in a dereference of a null pointer "
"(loaded from variable '" << VD->getName() << "')";
Ranges.push_back(M->getBase()->getSourceRange());
}
}
break;
}
default:
break;
@ -117,19 +134,23 @@ void DereferenceChecker::VisitLocation(CheckerContext &C, const Stmt *S,
report->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue,
bugreporter::GetDerefExpr(N));
for (llvm::SmallVectorImpl<SourceRange>::iterator
I = Ranges.begin(), E = Ranges.end(); I!=E; ++I)
report->addRange(*I);
C.EmitReport(report);
return;
}
else {
// Otherwise, we have the case where the location could either be
// null or not-null. Record the error node as an "implicit" null
// dereference.
// dereference.
if (ExplodedNode *N = C.GenerateSink(nullState))
ImplicitNullDerefNodes.push_back(N);
}
}
// From this point forward, we know that the location is not null.
C.addTransition(notNullState);
}

2
test/Analysis/inline.c
Просмотреть файл

@ -15,6 +15,6 @@ void f2() {
}
if (x == 2) {
int *p = 0;
*p = 3; // expected-warning{{Dereference of null pointer loaded from variable}}
*p = 3; // expected-warning{{Dereference of null pointer (loaded from variable 'p')}}
}
}

4
test/Analysis/null-deref-ps.c
Просмотреть файл

@ -26,7 +26,7 @@ int f2(struct foo_struct* p) {
if (p)
p->x = 1;
return p->x++; // expected-warning{{Dereference of null pointer}}
return p->x++; // expected-warning{{Field access results in a dereference of a null pointer (loaded from variable 'p')}}
}
int f3(char* x) {
@ -57,7 +57,7 @@ int f4(int *p) {
return 1;
int *q = (int*) x;
return *q; // expected-warning{{Dereference of null pointer loaded from variable 'q'}}
return *q; // expected-warning{{Dereference of null pointer (loaded from variable 'q')}}
}
int f4_b() {

40
test/Analysis/plist-output.m
Просмотреть файл

@ -124,7 +124,7 @@ void test_null_field(void) {
// CHECK: <array>
// CHECK: <dict>
// CHECK: <key>line</key><integer>5</integer>
// CHECK: <key>col</key><integer>3</integer>
// CHECK: <key>col</key><integer>4</integer>
// CHECK: <key>file</key><integer>0</integer>
// CHECK: </dict>
// CHECK: <dict>
@ -135,12 +135,12 @@ void test_null_field(void) {
// CHECK: </array>
// CHECK: </array>
// CHECK: <key>extended_message</key>
// CHECK: <string>Dereference of null pointer loaded from variable &apos;p&apos;</string>
// CHECK: <string>Dereference of null pointer (loaded from variable &apos;p&apos;)</string>
// CHECK: <key>message</key>
// CHECK: <string>Dereference of null pointer loaded from variable &apos;p&apos;</string>
// CHECK: <string>Dereference of null pointer (loaded from variable &apos;p&apos;)</string>
// CHECK: </dict>
// CHECK: </array>
// CHECK: <key>description</key><string>Dereference of null pointer loaded from variable &apos;p&apos;</string>
// CHECK: <key>description</key><string>Dereference of null pointer (loaded from variable &apos;p&apos;)</string>
// CHECK: <key>category</key><string>Logic error</string>
// CHECK: <key>type</key><string>Dereference of null pointer</string>
// CHECK: <key>location</key>
@ -262,7 +262,7 @@ void test_null_field(void) {
// CHECK: <array>
// CHECK: <dict>
// CHECK: <key>line</key><integer>11</integer>
// CHECK: <key>col</key><integer>3</integer>
// CHECK: <key>col</key><integer>4</integer>
// CHECK: <key>file</key><integer>0</integer>
// CHECK: </dict>
// CHECK: <dict>
@ -273,12 +273,12 @@ void test_null_field(void) {
// CHECK: </array>
// CHECK: </array>
// CHECK: <key>extended_message</key>
// CHECK: <string>Dereference of null pointer loaded from variable &apos;p&apos;</string>
// CHECK: <string>Dereference of null pointer (loaded from variable &apos;p&apos;)</string>
// CHECK: <key>message</key>
// CHECK: <string>Dereference of null pointer loaded from variable &apos;p&apos;</string>
// CHECK: <string>Dereference of null pointer (loaded from variable &apos;p&apos;)</string>
// CHECK: </dict>
// CHECK: </array>
// CHECK: <key>description</key><string>Dereference of null pointer loaded from variable &apos;p&apos;</string>
// CHECK: <key>description</key><string>Dereference of null pointer (loaded from variable &apos;p&apos;)</string>
// CHECK: <key>category</key><string>Logic error</string>
// CHECK: <key>type</key><string>Dereference of null pointer</string>
// CHECK: <key>location</key>
@ -400,7 +400,7 @@ void test_null_field(void) {
// CHECK: <array>
// CHECK: <dict>
// CHECK: <key>line</key><integer>18</integer>
// CHECK: <key>col</key><integer>3</integer>
// CHECK: <key>col</key><integer>4</integer>
// CHECK: <key>file</key><integer>0</integer>
// CHECK: </dict>
// CHECK: <dict>
@ -411,12 +411,12 @@ void test_null_field(void) {
// CHECK: </array>
// CHECK: </array>
// CHECK: <key>extended_message</key>
// CHECK: <string>Dereference of null pointer loaded from variable &apos;q&apos;</string>
// CHECK: <string>Dereference of null pointer (loaded from variable &apos;q&apos;)</string>
// CHECK: <key>message</key>
// CHECK: <string>Dereference of null pointer loaded from variable &apos;q&apos;</string>
// CHECK: <string>Dereference of null pointer (loaded from variable &apos;q&apos;)</string>
// CHECK: </dict>
// CHECK: </array>
// CHECK: <key>description</key><string>Dereference of null pointer loaded from variable &apos;q&apos;</string>
// CHECK: <key>description</key><string>Dereference of null pointer (loaded from variable &apos;q&apos;)</string>
// CHECK: <key>category</key><string>Logic error</string>
// CHECK: <key>type</key><string>Dereference of null pointer</string>
// CHECK: <key>location</key>
@ -538,7 +538,7 @@ void test_null_field(void) {
// CHECK: <array>
// CHECK: <dict>
// CHECK: <key>line</key><integer>23</integer>
// CHECK: <key>col</key><integer>5</integer>
// CHECK: <key>col</key><integer>6</integer>
// CHECK: <key>file</key><integer>0</integer>
// CHECK: </dict>
// CHECK: <dict>
@ -549,12 +549,12 @@ void test_null_field(void) {
// CHECK: </array>
// CHECK: </array>
// CHECK: <key>extended_message</key>
// CHECK: <string>Dereference of null pointer loaded from variable &apos;p&apos;</string>
// CHECK: <string>Dereference of null pointer (loaded from variable &apos;p&apos;)</string>
// CHECK: <key>message</key>
// CHECK: <string>Dereference of null pointer loaded from variable &apos;p&apos;</string>
// CHECK: <string>Dereference of null pointer (loaded from variable &apos;p&apos;)</string>
// CHECK: </dict>
// CHECK: </array>
// CHECK: <key>description</key><string>Dereference of null pointer loaded from variable &apos;p&apos;</string>
// CHECK: <key>description</key><string>Dereference of null pointer (loaded from variable &apos;p&apos;)</string>
// CHECK: <key>category</key><string>Logic error</string>
// CHECK: <key>type</key><string>Dereference of null pointer</string>
// CHECK: <key>location</key>
@ -710,7 +710,7 @@ void test_null_field(void) {
// CHECK: <array>
// CHECK: <dict>
// CHECK: <key>line</key><integer>30</integer>
// CHECK: <key>col</key><integer>5</integer>
// CHECK: <key>col</key><integer>6</integer>
// CHECK: <key>file</key><integer>0</integer>
// CHECK: </dict>
// CHECK: <dict>
@ -721,12 +721,12 @@ void test_null_field(void) {
// CHECK: </array>
// CHECK: </array>
// CHECK: <key>extended_message</key>
// CHECK: <string>Dereference of null pointer loaded from variable &apos;p&apos;</string>
// CHECK: <string>Dereference of null pointer (loaded from variable &apos;p&apos;)</string>
// CHECK: <key>message</key>
// CHECK: <string>Dereference of null pointer loaded from variable &apos;p&apos;</string>
// CHECK: <string>Dereference of null pointer (loaded from variable &apos;p&apos;)</string>
// CHECK: </dict>
// CHECK: </array>
// CHECK: <key>description</key><string>Dereference of null pointer loaded from variable &apos;p&apos;</string>
// CHECK: <key>description</key><string>Dereference of null pointer (loaded from variable &apos;p&apos;)</string>
// CHECK: <key>category</key><string>Logic error</string>
// CHECK: <key>type</key><string>Dereference of null pointer</string>
// CHECK: <key>location</key>