Chris Lattner has strong opinions about directory
layout. :)
Rename the 'EntoSA' directories to 'StaticAnalyzer'.
Internally we will still use the 'ento' namespace
for the analyzer engine (unless there are further
sabre rattlings...).
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@122514 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/StaticAnalyzer/Checkers/ObjCUnusedIVarsChecker.cpp b/lib/StaticAnalyzer/Checkers/ObjCUnusedIVarsChecker.cpp
new file mode 100644
index 0000000..799da33
--- /dev/null
+++ b/lib/StaticAnalyzer/Checkers/ObjCUnusedIVarsChecker.cpp
@@ -0,0 +1,164 @@
+//==- ObjCUnusedIVarsChecker.cpp - Check for unused ivars --------*- C++ -*-==//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines a CheckObjCUnusedIvars, a checker that
+// analyzes an Objective-C class's interface/implementation to determine if it
+// has any ivars that are never accessed.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/StaticAnalyzer/Checkers/LocalCheckers.h"
+#include "clang/StaticAnalyzer/BugReporter/PathDiagnostic.h"
+#include "clang/StaticAnalyzer/BugReporter/BugReporter.h"
+#include "clang/AST/ExprObjC.h"
+#include "clang/AST/Expr.h"
+#include "clang/AST/DeclObjC.h"
+#include "clang/Basic/LangOptions.h"
+#include "clang/Basic/SourceManager.h"
+
+using namespace clang;
+using namespace ento;
+
+enum IVarState { Unused, Used };
+typedef llvm::DenseMap<const ObjCIvarDecl*,IVarState> IvarUsageMap;
+
+static void Scan(IvarUsageMap& M, const Stmt* S) {
+ if (!S)
+ return;
+
+ if (const ObjCIvarRefExpr *Ex = dyn_cast<ObjCIvarRefExpr>(S)) {
+ const ObjCIvarDecl *D = Ex->getDecl();
+ IvarUsageMap::iterator I = M.find(D);
+ if (I != M.end())
+ I->second = Used;
+ return;
+ }
+
+ // Blocks can reference an instance variable of a class.
+ if (const BlockExpr *BE = dyn_cast<BlockExpr>(S)) {
+ Scan(M, BE->getBody());
+ return;
+ }
+
+ for (Stmt::const_child_iterator I=S->child_begin(),E=S->child_end(); I!=E;++I)
+ Scan(M, *I);
+}
+
+static void Scan(IvarUsageMap& M, const ObjCPropertyImplDecl* D) {
+ if (!D)
+ return;
+
+ const ObjCIvarDecl* ID = D->getPropertyIvarDecl();
+
+ if (!ID)
+ return;
+
+ IvarUsageMap::iterator I = M.find(ID);
+ if (I != M.end())
+ I->second = Used;
+}
+
+static void Scan(IvarUsageMap& M, const ObjCContainerDecl* D) {
+ // Scan the methods for accesses.
+ for (ObjCContainerDecl::instmeth_iterator I = D->instmeth_begin(),
+ E = D->instmeth_end(); I!=E; ++I)
+ Scan(M, (*I)->getBody());
+
+ if (const ObjCImplementationDecl *ID = dyn_cast<ObjCImplementationDecl>(D)) {
+ // Scan for @synthesized property methods that act as setters/getters
+ // to an ivar.
+ for (ObjCImplementationDecl::propimpl_iterator I = ID->propimpl_begin(),
+ E = ID->propimpl_end(); I!=E; ++I)
+ Scan(M, *I);
+
+ // Scan the associated categories as well.
+ for (const ObjCCategoryDecl *CD =
+ ID->getClassInterface()->getCategoryList(); CD ;
+ CD = CD->getNextClassCategory()) {
+ if (const ObjCCategoryImplDecl *CID = CD->getImplementation())
+ Scan(M, CID);
+ }
+ }
+}
+
+static void Scan(IvarUsageMap &M, const DeclContext *C, const FileID FID,
+ SourceManager &SM) {
+ for (DeclContext::decl_iterator I=C->decls_begin(), E=C->decls_end();
+ I!=E; ++I)
+ if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) {
+ SourceLocation L = FD->getLocStart();
+ if (SM.getFileID(L) == FID)
+ Scan(M, FD->getBody());
+ }
+}
+
+void ento::CheckObjCUnusedIvar(const ObjCImplementationDecl *D,
+ BugReporter &BR) {
+
+ const ObjCInterfaceDecl* ID = D->getClassInterface();
+ IvarUsageMap M;
+
+ // Iterate over the ivars.
+ for (ObjCInterfaceDecl::ivar_iterator I=ID->ivar_begin(),
+ E=ID->ivar_end(); I!=E; ++I) {
+
+ const ObjCIvarDecl* ID = *I;
+
+ // Ignore ivars that...
+ // (a) aren't private
+ // (b) explicitly marked unused
+ // (c) are iboutlets
+ // (d) are unnamed bitfields
+ if (ID->getAccessControl() != ObjCIvarDecl::Private ||
+ ID->getAttr<UnusedAttr>() || ID->getAttr<IBOutletAttr>() ||
+ ID->getAttr<IBOutletCollectionAttr>() ||
+ ID->isUnnamedBitfield())
+ continue;
+
+ M[ID] = Unused;
+ }
+
+ if (M.empty())
+ return;
+
+ // Now scan the implementation declaration.
+ Scan(M, D);
+
+ // Any potentially unused ivars?
+ bool hasUnused = false;
+ for (IvarUsageMap::iterator I = M.begin(), E = M.end(); I!=E; ++I)
+ if (I->second == Unused) {
+ hasUnused = true;
+ break;
+ }
+
+ if (!hasUnused)
+ return;
+
+ // We found some potentially unused ivars. Scan the entire translation unit
+ // for functions inside the @implementation that reference these ivars.
+ // FIXME: In the future hopefully we can just use the lexical DeclContext
+ // to go from the ObjCImplementationDecl to the lexically "nested"
+ // C functions.
+ SourceManager &SM = BR.getSourceManager();
+ Scan(M, D->getDeclContext(), SM.getFileID(D->getLocation()), SM);
+
+ // Find ivars that are unused.
+ for (IvarUsageMap::iterator I = M.begin(), E = M.end(); I!=E; ++I)
+ if (I->second == Unused) {
+ std::string sbuf;
+ llvm::raw_string_ostream os(sbuf);
+ os << "Instance variable '" << I->first << "' in class '" << ID
+ << "' is never used by the methods in its @implementation "
+ "(although it may be used by category methods).";
+
+ BR.EmitBasicReport("Unused instance variable", "Optimization",
+ os.str(), I->first->getLocation());
+ }
+}