[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

1 files changed, 24 insertions, 5 deletions

diff --git a/clang/lib/StaticAnalyzer/Core/CheckerHelpers.cpp b/clang/lib/StaticAnalyzer/Core/CheckerHelpers.cpp
index ed41914ebd0..b9facffcc8b 100644
--- a/clang/lib/StaticAnalyzer/Core/CheckerHelpers.cpp
+++ b/clang/lib/StaticAnalyzer/Core/CheckerHelpers.cpp
@@ -15,8 +15,12 @@
 #include "clang/AST/Decl.h"
 #include "clang/AST/Expr.h"
 
+namespace clang {
+
+namespace ento {
+
 // Recursively find any substatements containing macros
-bool clang::ento::containsMacro(const Stmt *S) {
+bool containsMacro(const Stmt *S) {
   if (S->getLocStart().isMacroID())
     return true;
 
@@ -31,7 +35,7 @@ bool clang::ento::containsMacro(const Stmt *S) {
 }
 
 // Recursively find any substatements containing enum constants
-bool clang::ento::containsEnum(const Stmt *S) {
+bool containsEnum(const Stmt *S) {
   const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(S);
 
   if (DR && isa<EnumConstantDecl>(DR->getDecl()))
@@ -45,7 +49,7 @@ bool clang::ento::containsEnum(const Stmt *S) {
 }
 
 // Recursively find any substatements containing static vars
-bool clang::ento::containsStaticLocal(const Stmt *S) {
+bool containsStaticLocal(const Stmt *S) {
   const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(S);
 
   if (DR)
@@ -61,7 +65,7 @@ bool clang::ento::containsStaticLocal(const Stmt *S) {
 }
 
 // Recursively find any substatements containing __builtin_offsetof
-bool clang::ento::containsBuiltinOffsetOf(const Stmt *S) {
+bool containsBuiltinOffsetOf(const Stmt *S) {
   if (isa<OffsetOfExpr>(S))
     return true;
 
@@ -74,7 +78,7 @@ bool clang::ento::containsBuiltinOffsetOf(const Stmt *S) {
 
 // Extract lhs and rhs from assignment statement
 std::pair<const clang::VarDecl *, const clang::Expr *>
-clang::ento::parseAssignment(const Stmt *S) {
+parseAssignment(const Stmt *S) {
   const VarDecl *VD = nullptr;
   const Expr *RHS = nullptr;
 
@@ -94,3 +98,18 @@ clang::ento::parseAssignment(const Stmt *S) {
 
   return std::make_pair(VD, RHS);
 }
+
+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;
+}
+
+
+} // end namespace ento
+} // end namespace clang