replica
/
hanchenye-llvm-project
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

This patch reverts r220496 which issues warning on comparing 

parameters with nonnull attribute when comparison is always
true/false. Patch causes false positive when parameter is
modified in the function.

llvm-svn: 221163
This commit is contained in:
Fariborz Jahanian 2014-11-03 17:03:07 +00:00
parent 3f6469b4c6
commit d6efd3e0d0
3 changed files with 1 additions and 64 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
clang/include/clang/Basic/DiagnosticSemaKinds.td
View File

@ -2507,10 +2507,6 @@ def warn_impcast_pointer_to_bool : Warning<
"address of%select{| function| array}0 '%1' will always evaluate to " "address of%select{| function| array}0 '%1' will always evaluate to "
"'true'">, "'true'">,
InGroup<PointerBoolConversion>; InGroup<PointerBoolConversion>;
def warn_cast_nonnull_to_bool : Warning<
"nonnull parameter '%0' will always evaluate to "
"'true'">,
InGroup<PointerBoolConversion>;
def warn_this_bool_conversion : Warning< def warn_this_bool_conversion : Warning<
"'this' pointer cannot be null in well-defined C++ code; pointer may be " "'this' pointer cannot be null in well-defined C++ code; pointer may be "
"assumed to always convert to true">, InGroup<UndefinedBoolConversion>; "assumed to always convert to true">, InGroup<UndefinedBoolConversion>;
@ -2523,10 +2519,6 @@ def warn_null_pointer_compare : Warning<
"comparison of %select{address of|function|array}0 '%1' %select{not |}2" "comparison of %select{address of|function|array}0 '%1' %select{not |}2"
"equal to a null pointer is always %select{true|false}2">, "equal to a null pointer is always %select{true|false}2">,
InGroup<TautologicalPointerCompare>; InGroup<TautologicalPointerCompare>;
def warn_nonnull_parameter_compare : Warning<
"comparison of nonnull parameter '%0' %select{not |}1"
"equal to a null pointer is always %select{true|false}1">,
InGroup<TautologicalPointerCompare>;
def warn_this_null_compare : Warning< def warn_this_null_compare : Warning<
"'this' pointer cannot be null in well-defined C++ code; comparison may be " "'this' pointer cannot be null in well-defined C++ code; comparison may be "
"assumed to always evaluate to %select{true|false}0">, "assumed to always evaluate to %select{true|false}0">,

30
clang/lib/Sema/SemaChecking.cpp
View File

@ -6678,36 +6678,6 @@ void Sema::DiagnoseAlwaysNonNullPointer(Expr *E,
// Weak Decls can be null. // Weak Decls can be null.
if (!D || D->isWeak()) if (!D || D->isWeak())
return; 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(); QualType T = D->getType();
const bool IsArray = T->isArrayType(); const bool IsArray = T->isArrayType();

25
clang/test/Sema/nonnull.c
View File

@ -83,28 +83,3 @@ void redecl_test(void *p) {
redecl(p, 0); // expected-warning{{null passed}} redecl(p, 0); // expected-warning{{null passed}}
redecl(0, p); // expected-warning{{null passed}} redecl(0, p); // expected-warning{{null passed}}
} }
// rdar://18712242
#define NULL (void*)0
__attribute__((__nonnull__))
int evil_nonnull_func(int* pointer, void * pv)
{
if (pointer == NULL) { // expected-warning {{comparison of nonnull parameter 'pointer' equal to a null pointer is always false}}
return 0;
} else {
return *pointer;
}
if (pv == NULL) {} // expected-warning {{comparison of nonnull parameter 'pv' equal to a null pointer is always false}}
}
int another_evil_nonnull_func(int* pointer, char ch, void * pv) __attribute__((nonnull(1, 3)));
int another_evil_nonnull_func(int* pointer, char ch, void * pv) {
if (pointer == NULL) { // expected-warning {{comparison of nonnull parameter 'pointer' equal to a null pointer is always false}}
return 0;
} else {
return *pointer;
}
if (pv == NULL) {} // expected-warning {{comparison of nonnull parameter 'pv' equal to a null pointer is always false}}
}