r315655 - [Analyzer] Assume that CFBooleanRef const globals are non-null
George Karpenkov via cfe-commits
cfe-commits at lists.llvm.org
Thu Oct 12 17:51:41 PDT 2017
Author: george.karpenkov
Date: Thu Oct 12 17:51:41 2017
New Revision: 315655
URL: http://llvm.org/viewvc/llvm-project?rev=315655&view=rev
Log:
[Analyzer] Assume that CFBooleanRef const globals are non-null
Differential Revision: https://reviews.llvm.org/D38867
Added:
cfe/trunk/lib/StaticAnalyzer/Checkers/NonnullGlobalConstantsChecker.cpp
- copied, changed from r315652, cfe/trunk/lib/StaticAnalyzer/Checkers/NonnullStringConstantsChecker.cpp
cfe/trunk/test/Analysis/nonnull-global-constants.mm
- copied, changed from r315652, cfe/trunk/test/Analysis/nonnull-string-constants.mm
Removed:
cfe/trunk/lib/StaticAnalyzer/Checkers/NonnullStringConstantsChecker.cpp
cfe/trunk/test/Analysis/nonnull-string-constants.mm
Modified:
cfe/trunk/include/clang/StaticAnalyzer/Checkers/Checkers.td
cfe/trunk/lib/StaticAnalyzer/Checkers/CMakeLists.txt
Modified: cfe/trunk/include/clang/StaticAnalyzer/Checkers/Checkers.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/StaticAnalyzer/Checkers/Checkers.td?rev=315655&r1=315654&r2=315655&view=diff
==============================================================================
--- cfe/trunk/include/clang/StaticAnalyzer/Checkers/Checkers.td (original)
+++ cfe/trunk/include/clang/StaticAnalyzer/Checkers/Checkers.td Thu Oct 12 17:51:41 2017
@@ -132,7 +132,7 @@ def DynamicTypePropagation : Checker<"Dy
HelpText<"Generate dynamic type information">,
DescFile<"DynamicTypePropagation.cpp">;
-def NonnullStringConstantsChecker: Checker<"NonnilStringConstants">,
+def NonnullGlobalConstantsChecker: Checker<"NonnilStringConstants">,
HelpText<"Assume that const string-like globals are non-null">,
DescFile<"NonilStringConstantsChecker.cpp">;
Modified: cfe/trunk/lib/StaticAnalyzer/Checkers/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Checkers/CMakeLists.txt?rev=315655&r1=315654&r2=315655&view=diff
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Checkers/CMakeLists.txt (original)
+++ cfe/trunk/lib/StaticAnalyzer/Checkers/CMakeLists.txt Thu Oct 12 17:51:41 2017
@@ -57,7 +57,7 @@ add_clang_library(clangStaticAnalyzerChe
NSErrorChecker.cpp
NoReturnFunctionChecker.cpp
NonNullParamChecker.cpp
- NonnullStringConstantsChecker.cpp
+ NonnullGlobalConstantsChecker.cpp
NullabilityChecker.cpp
NumberObjectConversionChecker.cpp
ObjCAtSyncChecker.cpp
Copied: cfe/trunk/lib/StaticAnalyzer/Checkers/NonnullGlobalConstantsChecker.cpp (from r315652, cfe/trunk/lib/StaticAnalyzer/Checkers/NonnullStringConstantsChecker.cpp)
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Checkers/NonnullGlobalConstantsChecker.cpp?p2=cfe/trunk/lib/StaticAnalyzer/Checkers/NonnullGlobalConstantsChecker.cpp&p1=cfe/trunk/lib/StaticAnalyzer/Checkers/NonnullStringConstantsChecker.cpp&r1=315652&r2=315655&rev=315655&view=diff
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Checkers/NonnullStringConstantsChecker.cpp (original)
+++ cfe/trunk/lib/StaticAnalyzer/Checkers/NonnullGlobalConstantsChecker.cpp Thu Oct 12 17:51:41 2017
@@ -1,4 +1,4 @@
-//==- NonnullStringConstantsChecker.cpp ---------------------------*- C++ -*--//
+//==- NonnullGlobalConstantsChecker.cpp ---------------------------*- C++ -*--//
//
// The LLVM Compiler Infrastructure
//
@@ -7,15 +7,17 @@
//
//===----------------------------------------------------------------------===//
//
-// This checker adds an assumption that constant string-like globals are
+// This checker adds an assumption that constant globals of certain types* are
// non-null, as otherwise they generally do not convey any useful information.
-// The assumption is useful, as many framework use such global const strings,
+// The assumption is useful, as many framework use e. g. global const strings,
// and the analyzer might not be able to infer the global value if the
// definition is in a separate translation unit.
-// The following types (and their typedef aliases) are considered string-like:
+// The following types (and their typedef aliases) are considered to be
+// non-null:
// - `char* const`
// - `const CFStringRef` from CoreFoundation
// - `NSString* const` from Foundation
+// - `CFBooleanRef` from Foundation
//
//===----------------------------------------------------------------------===//
@@ -31,12 +33,13 @@ using namespace ento;
namespace {
-class NonnullStringConstantsChecker : public Checker<check::Location> {
+class NonnullGlobalConstantsChecker : public Checker<check::Location> {
mutable IdentifierInfo *NSStringII = nullptr;
mutable IdentifierInfo *CFStringRefII = nullptr;
+ mutable IdentifierInfo *CFBooleanRefII = nullptr;
public:
- NonnullStringConstantsChecker() {}
+ NonnullGlobalConstantsChecker() {}
void checkLocation(SVal l, bool isLoad, const Stmt *S,
CheckerContext &C) const;
@@ -46,22 +49,23 @@ private:
bool isGlobalConstString(SVal V) const;
- bool isStringlike(QualType Ty) const;
+ bool isNonnullType(QualType Ty) const;
};
} // namespace
/// Lazily initialize cache for required identifier informations.
-void NonnullStringConstantsChecker::initIdentifierInfo(ASTContext &Ctx) const {
+void NonnullGlobalConstantsChecker::initIdentifierInfo(ASTContext &Ctx) const {
if (NSStringII)
return;
NSStringII = &Ctx.Idents.get("NSString");
CFStringRefII = &Ctx.Idents.get("CFStringRef");
+ CFBooleanRefII = &Ctx.Idents.get("CFBooleanRef");
}
/// Add an assumption that const string-like globals are non-null.
-void NonnullStringConstantsChecker::checkLocation(SVal location, bool isLoad,
+void NonnullGlobalConstantsChecker::checkLocation(SVal location, bool isLoad,
const Stmt *S,
CheckerContext &C) const {
initIdentifierInfo(C.getASTContext());
@@ -85,7 +89,7 @@ void NonnullStringConstantsChecker::chec
/// \param V loaded lvalue.
/// \return whether {@code val} is a string-like const global.
-bool NonnullStringConstantsChecker::isGlobalConstString(SVal V) const {
+bool NonnullGlobalConstantsChecker::isGlobalConstString(SVal V) const {
Optional<loc::MemRegionVal> RegionVal = V.getAs<loc::MemRegionVal>();
if (!RegionVal)
return false;
@@ -99,7 +103,7 @@ bool NonnullStringConstantsChecker::isGl
QualType Ty = Decl->getType();
bool HasConst = Ty.isConstQualified();
- if (isStringlike(Ty) && HasConst)
+ if (isNonnullType(Ty) && HasConst)
return true;
// Look through the typedefs.
@@ -109,14 +113,14 @@ bool NonnullStringConstantsChecker::isGl
// It is sufficient for any intermediate typedef
// to be classified const.
HasConst = HasConst || Ty.isConstQualified();
- if (isStringlike(Ty) && HasConst)
+ if (isNonnullType(Ty) && HasConst)
return true;
}
return false;
}
-/// \return whether {@code type} is a string-like type.
-bool NonnullStringConstantsChecker::isStringlike(QualType Ty) const {
+/// \return whether {@code type} is extremely unlikely to be null
+bool NonnullGlobalConstantsChecker::isNonnullType(QualType Ty) const {
if (Ty->isPointerType() && Ty->getPointeeType()->isCharType())
return true;
@@ -125,11 +129,12 @@ bool NonnullStringConstantsChecker::isSt
return T->getInterfaceDecl() &&
T->getInterfaceDecl()->getIdentifier() == NSStringII;
} else if (auto *T = dyn_cast<TypedefType>(Ty)) {
- return T->getDecl()->getIdentifier() == CFStringRefII;
+ IdentifierInfo* II = T->getDecl()->getIdentifier();
+ return II == CFStringRefII || II == CFBooleanRefII;
}
return false;
}
-void ento::registerNonnullStringConstantsChecker(CheckerManager &Mgr) {
- Mgr.registerChecker<NonnullStringConstantsChecker>();
+void ento::registerNonnullGlobalConstantsChecker(CheckerManager &Mgr) {
+ Mgr.registerChecker<NonnullGlobalConstantsChecker>();
}
Removed: cfe/trunk/lib/StaticAnalyzer/Checkers/NonnullStringConstantsChecker.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Checkers/NonnullStringConstantsChecker.cpp?rev=315654&view=auto
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Checkers/NonnullStringConstantsChecker.cpp (original)
+++ cfe/trunk/lib/StaticAnalyzer/Checkers/NonnullStringConstantsChecker.cpp (removed)
@@ -1,135 +0,0 @@
-//==- NonnullStringConstantsChecker.cpp ---------------------------*- C++ -*--//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This checker adds an assumption that constant string-like globals are
-// non-null, as otherwise they generally do not convey any useful information.
-// The assumption is useful, as many framework use such global const strings,
-// and the analyzer might not be able to infer the global value if the
-// definition is in a separate translation unit.
-// The following types (and their typedef aliases) are considered string-like:
-// - `char* const`
-// - `const CFStringRef` from CoreFoundation
-// - `NSString* const` from Foundation
-//
-//===----------------------------------------------------------------------===//
-
-#include "ClangSACheckers.h"
-#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
-#include "clang/StaticAnalyzer/Core/Checker.h"
-#include "clang/StaticAnalyzer/Core/CheckerManager.h"
-#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
-#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
-
-using namespace clang;
-using namespace ento;
-
-namespace {
-
-class NonnullStringConstantsChecker : public Checker<check::Location> {
- mutable IdentifierInfo *NSStringII = nullptr;
- mutable IdentifierInfo *CFStringRefII = nullptr;
-
-public:
- NonnullStringConstantsChecker() {}
-
- void checkLocation(SVal l, bool isLoad, const Stmt *S,
- CheckerContext &C) const;
-
-private:
- void initIdentifierInfo(ASTContext &Ctx) const;
-
- bool isGlobalConstString(SVal V) const;
-
- bool isStringlike(QualType Ty) const;
-};
-
-} // namespace
-
-/// Lazily initialize cache for required identifier informations.
-void NonnullStringConstantsChecker::initIdentifierInfo(ASTContext &Ctx) const {
- if (NSStringII)
- return;
-
- NSStringII = &Ctx.Idents.get("NSString");
- CFStringRefII = &Ctx.Idents.get("CFStringRef");
-}
-
-/// Add an assumption that const string-like globals are non-null.
-void NonnullStringConstantsChecker::checkLocation(SVal location, bool isLoad,
- const Stmt *S,
- CheckerContext &C) const {
- initIdentifierInfo(C.getASTContext());
- if (!isLoad || !location.isValid())
- return;
-
- ProgramStateRef State = C.getState();
- SVal V = State->getSVal(location.castAs<Loc>());
-
- if (isGlobalConstString(location)) {
- Optional<DefinedOrUnknownSVal> Constr = V.getAs<DefinedOrUnknownSVal>();
-
- if (Constr) {
-
- // Assume that the variable is non-null.
- ProgramStateRef OutputState = State->assume(*Constr, true);
- C.addTransition(OutputState);
- }
- }
-}
-
-/// \param V loaded lvalue.
-/// \return whether {@code val} is a string-like const global.
-bool NonnullStringConstantsChecker::isGlobalConstString(SVal V) const {
- Optional<loc::MemRegionVal> RegionVal = V.getAs<loc::MemRegionVal>();
- if (!RegionVal)
- return false;
- auto *Region = dyn_cast<VarRegion>(RegionVal->getAsRegion());
- if (!Region)
- return false;
- const VarDecl *Decl = Region->getDecl();
-
- if (!Decl->hasGlobalStorage())
- return false;
-
- QualType Ty = Decl->getType();
- bool HasConst = Ty.isConstQualified();
- if (isStringlike(Ty) && HasConst)
- return true;
-
- // Look through the typedefs.
- while (auto *T = dyn_cast<TypedefType>(Ty)) {
- Ty = T->getDecl()->getUnderlyingType();
-
- // It is sufficient for any intermediate typedef
- // to be classified const.
- HasConst = HasConst || Ty.isConstQualified();
- if (isStringlike(Ty) && HasConst)
- return true;
- }
- return false;
-}
-
-/// \return whether {@code type} is a string-like type.
-bool NonnullStringConstantsChecker::isStringlike(QualType Ty) const {
-
- if (Ty->isPointerType() && Ty->getPointeeType()->isCharType())
- return true;
-
- if (auto *T = dyn_cast<ObjCObjectPointerType>(Ty)) {
- return T->getInterfaceDecl() &&
- T->getInterfaceDecl()->getIdentifier() == NSStringII;
- } else if (auto *T = dyn_cast<TypedefType>(Ty)) {
- return T->getDecl()->getIdentifier() == CFStringRefII;
- }
- return false;
-}
-
-void ento::registerNonnullStringConstantsChecker(CheckerManager &Mgr) {
- Mgr.registerChecker<NonnullStringConstantsChecker>();
-}
Copied: cfe/trunk/test/Analysis/nonnull-global-constants.mm (from r315652, cfe/trunk/test/Analysis/nonnull-string-constants.mm)
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/nonnull-global-constants.mm?p2=cfe/trunk/test/Analysis/nonnull-global-constants.mm&p1=cfe/trunk/test/Analysis/nonnull-string-constants.mm&r1=315652&r2=315655&rev=315655&view=diff
==============================================================================
--- cfe/trunk/test/Analysis/nonnull-string-constants.mm (original)
+++ cfe/trunk/test/Analysis/nonnull-global-constants.mm Thu Oct 12 17:51:41 2017
@@ -1,12 +1,13 @@
// RUN: %clang_analyze_cc1 -analyzer-checker=core,debug.ExprInspection -verify %s
// Nullability of const string-like globals, testing
-// NonnullStringConstantsChecker.
+// NonnullGlobalConstantsChecker.
void clang_analyzer_eval(bool);
@class NSString;
typedef const struct __CFString *CFStringRef;
+typedef const struct __CFBoolean * CFBooleanRef;
// Global NSString* is non-null.
extern NSString *const StringConstGlobal;
@@ -88,3 +89,15 @@ extern nstr2 nglobalStr2;
void testNestedTypedefsForNSString() {
clang_analyzer_eval(nglobalStr2); // expected-warning{{TRUE}}
}
+
+// And for CFBooleanRefs.
+extern const CFBooleanRef kBool;
+void testNonnullBool() {
+ clang_analyzer_eval(kBool); // expected-warning{{TRUE}}
+}
+
+// And again, only for const one.
+extern CFBooleanRef kBoolMutable;
+void testNonnullNonconstBool() {
+ clang_analyzer_eval(kBoolMutable); // expected-warning{{UNKNOWN}}
+}
Removed: cfe/trunk/test/Analysis/nonnull-string-constants.mm
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/nonnull-string-constants.mm?rev=315654&view=auto
==============================================================================
--- cfe/trunk/test/Analysis/nonnull-string-constants.mm (original)
+++ cfe/trunk/test/Analysis/nonnull-string-constants.mm (removed)
@@ -1,90 +0,0 @@
-// RUN: %clang_analyze_cc1 -analyzer-checker=core,debug.ExprInspection -verify %s
-
-// Nullability of const string-like globals, testing
-// NonnullStringConstantsChecker.
-
-void clang_analyzer_eval(bool);
-
- at class NSString;
-typedef const struct __CFString *CFStringRef;
-
-// Global NSString* is non-null.
-extern NSString *const StringConstGlobal;
-void stringConstGlobal() {
- clang_analyzer_eval(StringConstGlobal); // expected-warning{{TRUE}}
-}
-
-// The logic does not apply to local variables though.
-extern NSString *stringGetter();
-void stringConstLocal() {
- NSString *const local = stringGetter();
- clang_analyzer_eval(local); // expected-warning{{UNKNOWN}}
-}
-
-// Global const CFStringRef's are also assumed to be non-null.
-extern const CFStringRef CFStringConstGlobal;
-void cfStringCheckGlobal() {
- clang_analyzer_eval(CFStringConstGlobal); // expected-warning{{TRUE}}
-}
-
-// But only "const" ones.
-extern CFStringRef CFStringNonConstGlobal;
-void cfStringCheckMutableGlobal() {
- clang_analyzer_eval(CFStringNonConstGlobal); // expected-warning{{UNKNOWN}}
-}
-
-// char* const is also assumed to be non-null.
-extern const char *const ConstCharStarConst;
-void constCharStarCheckGlobal() {
- clang_analyzer_eval(ConstCharStarConst); // expected-warning{{TRUE}}
-}
-
-// Pointer value can be mutable.
-extern char *const CharStarConst;
-void charStarCheckGlobal() {
- clang_analyzer_eval(CharStarConst); // expected-warning{{TRUE}}
-}
-
-// But the pointer itself should be immutable.
-extern char *CharStar;
-void charStartCheckMutableGlobal() {
- clang_analyzer_eval(CharStar); // expected-warning{{UNKNOWN}}
-}
-
-// Type definitions should also work across typedefs, for pointers:
-typedef char *const str;
-extern str globalStr;
-void charStarCheckTypedef() {
- clang_analyzer_eval(globalStr); // expected-warning{{TRUE}}
-}
-
-// And for types.
-typedef NSString *const NStr;
-extern NStr globalNSString;
-void NSStringCheckTypedef() {
- clang_analyzer_eval(globalNSString); // expected-warning{{TRUE}}
-}
-
-// Note that constness could be either inside
-// the var declaration, or in a typedef.
-typedef NSString *NStr2;
-extern const NStr2 globalNSString2;
-void NSStringCheckConstTypedef() {
- clang_analyzer_eval(globalNSString2); // expected-warning{{TRUE}}
-}
-
-// Nested typedefs should work as well.
-typedef const CFStringRef str1;
-typedef str1 str2;
-extern str2 globalStr2;
-void testNestedTypedefs() {
- clang_analyzer_eval(globalStr2); // expected-warning{{TRUE}}
-}
-
-// And for NSString *.
-typedef NSString *const nstr1;
-typedef nstr1 nstr2;
-extern nstr2 nglobalStr2;
-void testNestedTypedefsForNSString() {
- clang_analyzer_eval(nglobalStr2); // expected-warning{{TRUE}}
-}
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