Refactor logic in ExprEngine for detecting 'noreturn' methods

in NSException to a helper object in libAnalysis that can also
be used by Sema.  Not sure if the predicate name 'isImplicitNoReturn'
is the best one, but we can massage that later.

No functionality change.

llvm-svn: 163759
This commit is contained in:
Ted Kremenek 2012-09-13 00:21:31 +00:00
parent f83315fd4a
commit 8b3f938697
6 changed files with 129 additions and 66 deletions

View File

@ -0,0 +1,46 @@
//= ObjCNoReturn.h - Handling of Cocoa APIs known not to return --*- C++ -*---//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements special handling of recognizing ObjC API hooks that
// do not return but aren't marked as such in API headers.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_ANALYSIS_DS_OBJCNORETURN
#define LLVM_CLANG_ANALYSIS_DS_OBJCNORETURN
#include "clang/Basic/IdentifierTable.h"
namespace clang {
class ASTContext;
class ObjCMessageExpr;
class ObjCNoReturn {
/// Cached "raise" selector.
Selector RaiseSel;
/// Cached identifier for "NSException".
IdentifierInfo *NSExceptionII;
enum { NUM_RAISE_SELECTORS = 2 };
/// Cached set of selectors in NSException that are 'noreturn'.
Selector NSExceptionInstanceRaiseSelectors[NUM_RAISE_SELECTORS];
public:
ObjCNoReturn(ASTContext &C);
/// Return true if the given message expression is known to never
/// return.
bool isImplicitNoReturn(const ObjCMessageExpr *ME);
};
}
#endif

View File

@ -16,6 +16,7 @@
#ifndef LLVM_CLANG_GR_EXPRENGINE
#define LLVM_CLANG_GR_EXPRENGINE
#include "clang/Analysis/DomainSpecific/ObjCNoReturn.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/SubEngine.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CoreEngine.h"
@ -75,12 +76,9 @@ class ExprEngine : public SubEngine {
unsigned int currStmtIdx;
const NodeBuilderContext *currBldrCtx;
/// Obj-C Class Identifiers.
IdentifierInfo* NSExceptionII;
/// Obj-C Selectors.
Selector* NSExceptionInstanceRaiseSelectors;
Selector RaiseSel;
/// Helper object to determine if an Objective-C message expression
/// implicitly never returns.
ObjCNoReturn ObjCNoRet;
/// Whether or not GC is enabled in this analysis.
bool ObjCGCEnabled;

View File

@ -1,13 +1,14 @@
add_clang_library(clangAnalysis
AnalysisDeclContext.cpp
CallGraph.cpp
CFG.cpp
CFGReachabilityAnalysis.cpp
CFGStmtMap.cpp
CallGraph.cpp
CocoaConventions.cpp
Dominators.cpp
FormatString.cpp
LiveVariables.cpp
ObjCNoReturn.cpp
PostOrderCFGView.cpp
PrintfFormatString.cpp
ProgramPoint.cpp

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@ -0,0 +1,67 @@
//= ObjCNoReturn.cpp - Handling of Cocoa APIs known not to return --*- C++ -*---
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements special handling of recognizing ObjC API hooks that
// do not return but aren't marked as such in API headers.
//
//===----------------------------------------------------------------------===//
#include "clang/AST/ASTContext.h"
#include "clang/AST/ExprObjC.h"
#include "clang/Analysis/DomainSpecific/ObjCNoReturn.h"
using namespace clang;
static bool isSubclass(const ObjCInterfaceDecl *Class, IdentifierInfo *II) {
if (!Class)
return false;
if (Class->getIdentifier() == II)
return true;
return isSubclass(Class->getSuperClass(), II);
}
ObjCNoReturn::ObjCNoReturn(ASTContext &C)
: RaiseSel(GetNullarySelector("raise", C)),
NSExceptionII(&C.Idents.get("NSException"))
{
// Generate selectors.
SmallVector<IdentifierInfo*, 3> II;
// raise:format:
II.push_back(&C.Idents.get("raise"));
II.push_back(&C.Idents.get("format"));
NSExceptionInstanceRaiseSelectors[0] =
C.Selectors.getSelector(II.size(), &II[0]);
// raise:format:arguments:
II.push_back(&C.Idents.get("arguments"));
NSExceptionInstanceRaiseSelectors[1] =
C.Selectors.getSelector(II.size(), &II[0]);
}
bool ObjCNoReturn::isImplicitNoReturn(const ObjCMessageExpr *ME) {
Selector S = ME->getSelector();
if (ME->isInstanceMessage()) {
// Check for the "raise" message.
return S == RaiseSel;
}
if (const ObjCInterfaceDecl *ID = ME->getReceiverInterface()) {
if (isSubclass(ID, NSExceptionII)) {
for (unsigned i = 0; i < NUM_RAISE_SELECTORS; ++i) {
if (S == NSExceptionInstanceRaiseSelectors[i])
return true;
}
}
}
return false;
}

View File

@ -68,8 +68,7 @@ ExprEngine::ExprEngine(AnalysisManager &mgr, bool gcEnabled,
svalBuilder(StateMgr.getSValBuilder()),
EntryNode(NULL),
currStmt(NULL), currStmtIdx(0), currBldrCtx(0),
NSExceptionII(NULL), NSExceptionInstanceRaiseSelectors(NULL),
RaiseSel(GetNullarySelector("raise", getContext())),
ObjCNoRet(mgr.getASTContext()),
ObjCGCEnabled(gcEnabled), BR(mgr, *this),
VisitedCallees(VisitedCalleesIn)
{
@ -81,7 +80,6 @@ ExprEngine::ExprEngine(AnalysisManager &mgr, bool gcEnabled,
ExprEngine::~ExprEngine() {
BR.FlushReports();
delete [] NSExceptionInstanceRaiseSelectors;
}
//===----------------------------------------------------------------------===//

View File

@ -132,14 +132,6 @@ void ExprEngine::VisitObjCForCollectionStmt(const ObjCForCollectionStmt *S,
getCheckerManager().runCheckersForPostStmt(Dst, Tmp, S, *this);
}
static bool isSubclass(const ObjCInterfaceDecl *Class, IdentifierInfo *II) {
if (!Class)
return false;
if (Class->getIdentifier() == II)
return true;
return isSubclass(Class->getSuperClass(), II);
}
void ExprEngine::VisitObjCMessage(const ObjCMessageExpr *ME,
ExplodedNode *Pred,
ExplodedNodeSet &Dst) {
@ -184,7 +176,7 @@ void ExprEngine::VisitObjCMessage(const ObjCMessageExpr *ME,
// Check if the "raise" message was sent.
assert(notNilState);
if (Msg->getSelector() == RaiseSel) {
if (ObjCNoRet.isImplicitNoReturn(ME)) {
// If we raise an exception, for now treat it as a sink.
// Eventually we will want to handle exceptions properly.
Bldr.generateSink(currStmt, Pred, State);
@ -198,53 +190,14 @@ void ExprEngine::VisitObjCMessage(const ObjCMessageExpr *ME,
}
}
} else {
// Check for special class methods.
if (const ObjCInterfaceDecl *Iface = Msg->getReceiverInterface()) {
if (!NSExceptionII) {
ASTContext &Ctx = getContext();
NSExceptionII = &Ctx.Idents.get("NSException");
}
if (isSubclass(Iface, NSExceptionII)) {
enum { NUM_RAISE_SELECTORS = 2 };
// Lazily create a cache of the selectors.
if (!NSExceptionInstanceRaiseSelectors) {
ASTContext &Ctx = getContext();
NSExceptionInstanceRaiseSelectors =
new Selector[NUM_RAISE_SELECTORS];
SmallVector<IdentifierInfo*, NUM_RAISE_SELECTORS> II;
unsigned idx = 0;
// raise:format:
II.push_back(&Ctx.Idents.get("raise"));
II.push_back(&Ctx.Idents.get("format"));
NSExceptionInstanceRaiseSelectors[idx++] =
Ctx.Selectors.getSelector(II.size(), &II[0]);
// raise:format:arguments:
II.push_back(&Ctx.Idents.get("arguments"));
NSExceptionInstanceRaiseSelectors[idx++] =
Ctx.Selectors.getSelector(II.size(), &II[0]);
}
Selector S = Msg->getSelector();
bool RaisesException = false;
for (unsigned i = 0; i < NUM_RAISE_SELECTORS; ++i) {
if (S == NSExceptionInstanceRaiseSelectors[i]) {
RaisesException = true;
break;
}
}
if (RaisesException) {
// Check for special class methods that are known to not return
// and that we should treat as a sink.
if (ObjCNoRet.isImplicitNoReturn(ME)) {
// If we raise an exception, for now treat it as a sink.
// Eventually we will want to handle exceptions properly.
Bldr.generateSink(currStmt, Pred, Pred->getState());
continue;
}
}
}
}
defaultEvalCall(Bldr, Pred, *UpdatedMsg);