Szelethus created this revision.
Szelethus added reviewers: NoQ, george.karpenkov, rnkovacs, xazax.hun.
Herald added subscribers: cfe-commits, mikhail.ramalho, a.sidorin, szepet,
whisperity.
The idea came from both @george.karpenkov
(https://reviews.llvm.org/D45532#1145592) and from bugzilla
(https://bugs.llvm.org/show_bug.cgi?id=37965).
Assigning an object with uninitialized value to a pointer/reference could be
intentional, especially if one writes a class that just initializes values.
struct Initializer {
int *a;
void initialize(/* ... */) {
a = /* ... */;
}
Initializer(int *a) : a(a) {}
};
void f() {
int b;
Initializer init(&b);
// ...
init.initialize(/* ... */);
}
I actually have seen some examples for this in LLVM. While I absolutely agree
that a flag like this would be neat, I also think that it should be disabled by
default, as for example some objects are only created with `malloc`/`new`, and
because I didn't find this functionality to be too noisy.
Repository:
rC Clang
https://reviews.llvm.org/D49438
Files:
lib/StaticAnalyzer/Checkers/UninitializedObjectChecker.cpp
test/Analysis/cxx-uninitialized-no-dereference.cpp
Index: test/Analysis/cxx-uninitialized-no-dereference.cpp
===================================================================
--- /dev/null
+++ test/Analysis/cxx-uninitialized-no-dereference.cpp
@@ -0,0 +1,26 @@
+// RUN: %clang_analyze_cc1 -analyzer-checker=core,alpha.cplusplus.UninitializedObject -analyzer-config alpha.cplusplus.UninitializedObject:NoDereference=true -std=c++11 -DPEDANTIC -verify %s
+
+class UninitPointerTest {
+ int *ptr; // expected-note{{uninitialized pointer 'this->ptr'}}
+ int dontGetFilteredByNonPedanticMode = 0;
+
+public:
+ UninitPointerTest() {} // expected-warning{{1 uninitialized field}}
+};
+
+void fUninitPointerTest() {
+ UninitPointerTest();
+}
+
+class UninitPointeeTest {
+ int *ptr; // no-note
+ int dontGetFilteredByNonPedanticMode = 0;
+
+public:
+ UninitPointeeTest(int *ptr) : ptr(ptr) {} // no-warning
+};
+
+void fUninitPointeeTest() {
+ int a;
+ UninitPointeeTest t(&a);
+}
Index: lib/StaticAnalyzer/Checkers/UninitializedObjectChecker.cpp
===================================================================
--- lib/StaticAnalyzer/Checkers/UninitializedObjectChecker.cpp
+++ lib/StaticAnalyzer/Checkers/UninitializedObjectChecker.cpp
@@ -10,7 +10,7 @@
// This file defines a checker that reports uninitialized fields in objects
// created after a constructor call.
//
-// This checker has two options:
+// This checker has several options:
// - "Pedantic" (boolean). If its not set or is set to false, the checker
// won't emit warnings for objects that don't have at least one initialized
// field. This may be set with
@@ -24,6 +24,12 @@
//
// `-analyzer-config alpha.cplusplus.UninitializedObject:NotesAsWarnings=true`.
//
+// - "NoDereference" (boolean). If set to true, the checker will not analyze
+// the pointee of pointer/reference fields, and will only check whether the
+// object itself is initialized. Defaults to false.
+//
+// `-analyzer-config alpha.cplusplus.UninitializedObject:NoDereference=true`.
+//
//===----------------------------------------------------------------------===//
#include "ClangSACheckers.h"
@@ -44,6 +50,7 @@
// These fields will be initialized when registering the checker.
bool IsPedantic;
bool ShouldConvertNotesToWarnings;
+ bool ShouldDereference;
UninitializedObjectChecker()
: BT_uninitField(new BuiltinBug(this, "Uninitialized fields")) {}
@@ -109,13 +116,16 @@
const TypedValueRegion *const ObjectR;
const bool IsPedantic;
+ const bool ShouldDereference;
+
bool IsAnyFieldInitialized = false;
UninitFieldSet UninitFields;
public:
FindUninitializedFields(ProgramStateRef State,
- const TypedValueRegion *const R, bool IsPedantic);
+ const TypedValueRegion *const R, bool IsPedantic,
+ bool ShouldDereference);
const UninitFieldSet &getUninitFields();
private:
@@ -261,8 +271,8 @@
if (!Object)
return;
- FindUninitializedFields F(Context.getState(), Object->getRegion(),
- IsPedantic);
+ FindUninitializedFields F(Context.getState(), Object->getRegion(), IsPedantic,
+ ShouldDereference);
const UninitFieldSet &UninitFields = F.getUninitFields();
@@ -326,8 +336,10 @@
//===----------------------------------------------------------------------===//
FindUninitializedFields::FindUninitializedFields(
- ProgramStateRef State, const TypedValueRegion *const R, bool IsPedantic)
- : State(State), ObjectR(R), IsPedantic(IsPedantic) {}
+ ProgramStateRef State, const TypedValueRegion *const R, bool IsPedantic,
+ bool ShouldDereference)
+ : State(State), ObjectR(R), IsPedantic(IsPedantic),
+ ShouldDereference(ShouldDereference) {}
const UninitFieldSet &FindUninitializedFields::getUninitFields() {
isNonUnionUninit(ObjectR, FieldChainInfo());
@@ -474,6 +486,11 @@
return addFieldToUninits({LocalChain, FR});
}
+ if (!ShouldDereference) {
+ IsAnyFieldInitialized = true;
+ return false;
+ }
+
const FieldDecl *FD = FR->getDecl();
// TODO: The dynamic type of a void pointer may be retrieved with
@@ -700,4 +717,6 @@
"Pedantic", /*DefaultVal*/ false, Chk);
Chk->ShouldConvertNotesToWarnings = Mgr.getAnalyzerOptions().getBooleanOption(
"NotesAsWarnings", /*DefaultVal*/ false, Chk);
+ Chk->ShouldDereference = !Mgr.getAnalyzerOptions().getBooleanOption(
+ "NoDereference", /*DefaultVal*/ false, Chk);
}
_______________________________________________
cfe-commits mailing list
[email protected]
http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
