patch to issue warning on comparing parameters with
nonnull attribute when comparison is always
true/false. Patch by Steven Wu with few fixes and minor
refactoring and adding tests by me. rdar://18712242
llvm-svn: 220496
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index fd2fa0c..495fa32 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -6678,7 +6678,37 @@
// Weak Decls can be null.
if (!D || D->isWeak())
return;
-
+ // Check for parameter decl with nonnull attribute
+ if (ParmVarDecl* PV = dyn_cast<ParmVarDecl>(D)) {
+ if (FunctionDecl* FD = dyn_cast<FunctionDecl>(PV->getDeclContext())) {
+ unsigned NumArgs = FD->getNumParams();
+ llvm::SmallBitVector AttrNonNull(NumArgs);
+ for (const auto *NonNull : FD->specific_attrs<NonNullAttr>()) {
+ if (!NonNull->args_size()) {
+ AttrNonNull.set(0, NumArgs);
+ break;
+ }
+ for (unsigned Val : NonNull->args()) {
+ if (Val >= NumArgs)
+ continue;
+ AttrNonNull.set(Val);
+ }
+ }
+ if (!AttrNonNull.empty())
+ for (unsigned i = 0; i < NumArgs; ++i)
+ if (FD->getParamDecl(i) == PV && AttrNonNull[i]) {
+ std::string Str;
+ llvm::raw_string_ostream S(Str);
+ E->printPretty(S, nullptr, getPrintingPolicy());
+ unsigned DiagID = IsCompare ? diag::warn_nonnull_parameter_compare
+ : diag::warn_cast_nonnull_to_bool;
+ Diag(E->getExprLoc(), DiagID) << S.str() << E->getSourceRange()
+ << Range << IsEqual;
+ return;
+ }
+ }
+ }
+
QualType T = D->getType();
const bool IsArray = T->isArrayType();
const bool IsFunction = T->isFunctionType();