[analyzer] Trust _Nonnull annotations for system framework
Changes the analyzer to believe that methods annotated with _Nonnull
from system frameworks indeed return non null objects.
Local methods with such annotation are still distrusted.
rdar://24291919
Differential Revision: https://reviews.llvm.org/D44341
llvm-svn: 328282
diff --git a/clang/lib/StaticAnalyzer/Checkers/NullabilityChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/NullabilityChecker.cpp
index b348453..6230d53 100644
--- a/clang/lib/StaticAnalyzer/Checkers/NullabilityChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/NullabilityChecker.cpp
@@ -30,6 +30,7 @@
#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
#include "clang/StaticAnalyzer/Core/Checker.h"
#include "clang/StaticAnalyzer/Core/CheckerManager.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerHelpers.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
@@ -40,21 +41,6 @@
using namespace ento;
namespace {
-// Do not reorder! The getMostNullable method relies on the order.
-// Optimization: Most pointers expected to be unspecified. When a symbol has an
-// unspecified or nonnull type non of the rules would indicate any problem for
-// that symbol. For this reason only nullable and contradicted nullability are
-// stored for a symbol. When a symbol is already contradicted, it can not be
-// casted back to nullable.
-enum class Nullability : char {
- Contradicted, // Tracked nullability is contradicted by an explicit cast. Do
- // not report any nullability related issue for this symbol.
- // This nullability is propagated aggressively to avoid false
- // positive results. See the comment on getMostNullable method.
- Nullable,
- Unspecified,
- Nonnull
-};
/// Returns the most nullable nullability. This is used for message expressions
/// like [receiver method], where the nullability of this expression is either
@@ -345,17 +331,6 @@
nullptr);
}
-static Nullability getNullabilityAnnotation(QualType Type) {
- const auto *AttrType = Type->getAs<AttributedType>();
- if (!AttrType)
- return Nullability::Unspecified;
- if (AttrType->getAttrKind() == AttributedType::attr_nullable)
- return Nullability::Nullable;
- else if (AttrType->getAttrKind() == AttributedType::attr_nonnull)
- return Nullability::Nonnull;
- return Nullability::Unspecified;
-}
-
/// Returns true when the value stored at the given location is null
/// and the passed in type is nonnnull.
static bool checkValueAtLValForInvariantViolation(ProgramStateRef State,
@@ -872,7 +847,7 @@
// are either item retrieval related or not interesting nullability wise.
// Using this fact, to keep the code easier to read just ignore the return
// value of every instance method of dictionaries.
- if (M.isInstanceMessage() && Name.find("Dictionary") != StringRef::npos) {
+ if (M.isInstanceMessage() && Name.contains("Dictionary")) {
State =
State->set<NullabilityMap>(ReturnRegion, Nullability::Contradicted);
C.addTransition(State);
@@ -880,7 +855,7 @@
}
// For similar reasons ignore some methods of Cocoa arrays.
StringRef FirstSelectorSlot = M.getSelector().getNameForSlot(0);
- if (Name.find("Array") != StringRef::npos &&
+ if (Name.contains("Array") &&
(FirstSelectorSlot == "firstObject" ||
FirstSelectorSlot == "lastObject")) {
State =
@@ -893,7 +868,7 @@
// encodings are used. Using lossless encodings is so frequent that ignoring
// this class of methods reduced the emitted diagnostics by about 30% on
// some projects (and all of that was false positives).
- if (Name.find("String") != StringRef::npos) {
+ if (Name.contains("String")) {
for (auto Param : M.parameters()) {
if (Param->getName() == "encoding") {
State = State->set<NullabilityMap>(ReturnRegion,