[cfe-commits] r146144 - in /cfe/trunk: lib/StaticAnalyzer/Checkers/CMakeLists.txt lib/StaticAnalyzer/Checkers/Checkers.td lib/StaticAnalyzer/Checkers/MallocSizeofChecker.cpp test/Analysis/malloc-sizeof.c
Peter Collingbourne
peter at pcc.me.uk
Thu Dec 8 00:31:14 PST 2011
Author: pcc
Date: Thu Dec 8 02:31:14 2011
New Revision: 146144
URL: http://llvm.org/viewvc/llvm-project?rev=146144&view=rev
Log:
Add an experimental MallocSizeofChecker, which reports inconsistencies
between the casted type of the return value of a malloc/calloc/realloc
call and the operand of any sizeof expressions contained within
its argument(s).
Added:
cfe/trunk/lib/StaticAnalyzer/Checkers/MallocSizeofChecker.cpp
cfe/trunk/test/Analysis/malloc-sizeof.c
Modified:
cfe/trunk/lib/StaticAnalyzer/Checkers/CMakeLists.txt
cfe/trunk/lib/StaticAnalyzer/Checkers/Checkers.td
Modified: cfe/trunk/lib/StaticAnalyzer/Checkers/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Checkers/CMakeLists.txt?rev=146144&r1=146143&r2=146144&view=diff
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Checkers/CMakeLists.txt (original)
+++ cfe/trunk/lib/StaticAnalyzer/Checkers/CMakeLists.txt Thu Dec 8 02:31:14 2011
@@ -37,6 +37,7 @@
MacOSXAPIChecker.cpp
MallocChecker.cpp
MallocOverflowSecurityChecker.cpp
+ MallocSizeofChecker.cpp
NSAutoreleasePoolChecker.cpp
NSErrorChecker.cpp
NoReturnFunctionChecker.cpp
Modified: cfe/trunk/lib/StaticAnalyzer/Checkers/Checkers.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Checkers/Checkers.td?rev=146144&r1=146143&r2=146144&view=diff
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Checkers/Checkers.td (original)
+++ cfe/trunk/lib/StaticAnalyzer/Checkers/Checkers.td Thu Dec 8 02:31:14 2011
@@ -256,6 +256,10 @@
HelpText<"Check for potential memory leaks, double free, and use-after-free problems">,
DescFile<"MallocChecker.cpp">;
+def MallocSizeofChecker : Checker<"MallocSizeof">,
+ HelpText<"Check for dubious malloc arguments involving sizeof">,
+ DescFile<"MallocSizeofChecker.cpp">;
+
def PthreadLockChecker : Checker<"PthreadLock">,
HelpText<"Simple lock -> unlock checker">,
DescFile<"PthreadLockChecker.cpp">;
Added: cfe/trunk/lib/StaticAnalyzer/Checkers/MallocSizeofChecker.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Checkers/MallocSizeofChecker.cpp?rev=146144&view=auto
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Checkers/MallocSizeofChecker.cpp (added)
+++ cfe/trunk/lib/StaticAnalyzer/Checkers/MallocSizeofChecker.cpp Thu Dec 8 02:31:14 2011
@@ -0,0 +1,208 @@
+// MallocSizeofChecker.cpp - Check for dubious malloc arguments ---*- C++ -*-=//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Reports inconsistencies between the casted type of the return value of a
+// malloc/calloc/realloc call and the operand of any sizeof expressions
+// contained within its argument(s).
+//
+//===----------------------------------------------------------------------===//
+
+#include "ClangSACheckers.h"
+#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
+#include "clang/StaticAnalyzer/Core/Checker.h"
+#include "clang/StaticAnalyzer/Core/CheckerManager.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
+#include "clang/AST/StmtVisitor.h"
+#include "clang/AST/TypeLoc.h"
+
+using namespace clang;
+using namespace ento;
+
+namespace {
+
+typedef std::pair<const TypeSourceInfo *, const CallExpr *> TypeCallPair;
+typedef llvm::PointerUnion<const Stmt *, const VarDecl *> ExprParent;
+
+class CastedAllocFinder
+ : public ConstStmtVisitor<CastedAllocFinder, TypeCallPair> {
+ IdentifierInfo *II_malloc, *II_calloc, *II_realloc;
+
+public:
+ struct CallRecord {
+ ExprParent CastedExprParent;
+ const Expr *CastedExpr;
+ const TypeSourceInfo *ExplicitCastType;
+ const CallExpr *AllocCall;
+
+ CallRecord(ExprParent CastedExprParent, const Expr *CastedExpr,
+ const TypeSourceInfo *ExplicitCastType,
+ const CallExpr *AllocCall)
+ : CastedExprParent(CastedExprParent), CastedExpr(CastedExpr),
+ ExplicitCastType(ExplicitCastType), AllocCall(AllocCall) {}
+ };
+
+ typedef std::vector<CallRecord> CallVec;
+ CallVec Calls;
+
+ CastedAllocFinder(ASTContext *Ctx) :
+ II_malloc(&Ctx->Idents.get("malloc")),
+ II_calloc(&Ctx->Idents.get("calloc")),
+ II_realloc(&Ctx->Idents.get("realloc")) {}
+
+ void VisitChild(ExprParent Parent, const Stmt *S) {
+ TypeCallPair AllocCall = Visit(S);
+ if (AllocCall.second && AllocCall.second != S)
+ Calls.push_back(CallRecord(Parent, cast<Expr>(S), AllocCall.first,
+ AllocCall.second));
+ }
+
+ void VisitChildren(const Stmt *S) {
+ for (Stmt::const_child_iterator I = S->child_begin(), E = S->child_end();
+ I!=E; ++I)
+ if (const Stmt *child = *I)
+ VisitChild(S, child);
+ }
+
+ TypeCallPair VisitCastExpr(const CastExpr *E) {
+ return Visit(E->getSubExpr());
+ }
+
+ TypeCallPair VisitExplicitCastExpr(const ExplicitCastExpr *E) {
+ return TypeCallPair(E->getTypeInfoAsWritten(),
+ Visit(E->getSubExpr()).second);
+ }
+
+ TypeCallPair VisitParenExpr(const ParenExpr *E) {
+ return Visit(E->getSubExpr());
+ }
+
+ TypeCallPair VisitStmt(const Stmt *S) {
+ VisitChildren(S);
+ return TypeCallPair();
+ }
+
+ TypeCallPair VisitCallExpr(const CallExpr *E) {
+ VisitChildren(E);
+ const FunctionDecl *FD = E->getDirectCallee();
+ if (FD) {
+ IdentifierInfo *II = FD->getIdentifier();
+ if (II == II_malloc || II == II_calloc || II == II_realloc)
+ return TypeCallPair(0, E);
+ }
+ return TypeCallPair();
+ }
+
+ TypeCallPair VisitDeclStmt(const DeclStmt *S) {
+ for (DeclStmt::const_decl_iterator I = S->decl_begin(), E = S->decl_end();
+ I!=E; ++I)
+ if (const VarDecl *VD = dyn_cast<VarDecl>(*I))
+ if (const Expr *Init = VD->getInit())
+ VisitChild(VD, Init);
+ return TypeCallPair();
+ }
+};
+
+class SizeofFinder : public ConstStmtVisitor<SizeofFinder> {
+public:
+ std::vector<const UnaryExprOrTypeTraitExpr *> Sizeofs;
+
+ void VisitBinMul(const BinaryOperator *E) {
+ Visit(E->getLHS());
+ Visit(E->getRHS());
+ }
+
+ void VisitBinAdd(const BinaryOperator *E) {
+ Visit(E->getLHS());
+ Visit(E->getRHS());
+ }
+
+ void VisitImplicitCastExpr(const ImplicitCastExpr *E) {
+ return Visit(E->getSubExpr());
+ }
+
+ void VisitParenExpr(const ParenExpr *E) {
+ return Visit(E->getSubExpr());
+ }
+
+ void VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *E) {
+ if (E->getKind() != UETT_SizeOf)
+ return;
+
+ Sizeofs.push_back(E);
+ }
+};
+
+class MallocSizeofChecker : public Checker<check::ASTCodeBody> {
+public:
+ void checkASTCodeBody(const Decl *D, AnalysisManager& mgr,
+ BugReporter &BR) const {
+ AnalysisDeclContext *ADC = mgr.getAnalysisDeclContext(D);
+ CastedAllocFinder Finder(&BR.getContext());
+ Finder.Visit(D->getBody());
+ for (CastedAllocFinder::CallVec::iterator i = Finder.Calls.begin(),
+ e = Finder.Calls.end(); i != e; ++i) {
+ QualType CastedType = i->CastedExpr->getType();
+ if (!CastedType->isPointerType())
+ continue;
+ QualType PointeeType = CastedType->getAs<PointerType>()->getPointeeType();
+ if (PointeeType->isVoidType())
+ continue;
+
+ for (CallExpr::const_arg_iterator ai = i->AllocCall->arg_begin(),
+ ae = i->AllocCall->arg_end(); ai != ae; ++ai) {
+ if (!(*ai)->getType()->isIntegerType())
+ continue;
+
+ SizeofFinder SFinder;
+ SFinder.Visit(*ai);
+ if (SFinder.Sizeofs.size() != 1)
+ continue;
+
+ QualType SizeofType = SFinder.Sizeofs[0]->getTypeOfArgument();
+ if (!BR.getContext().hasSameUnqualifiedType(PointeeType, SizeofType)) {
+ const TypeSourceInfo *TSI = 0;
+ if (i->CastedExprParent.is<const VarDecl *>()) {
+ TSI =
+ i->CastedExprParent.get<const VarDecl *>()->getTypeSourceInfo();
+ } else {
+ TSI = i->ExplicitCastType;
+ }
+
+ llvm::SmallString<64> buf;
+ llvm::raw_svector_ostream OS(buf);
+
+ OS << "Result of '"
+ << i->AllocCall->getDirectCallee()->getIdentifier()->getName()
+ << "' is converted to type '"
+ << CastedType.getAsString() << "', whose pointee type '"
+ << PointeeType.getAsString() << "' is incompatible with "
+ << "sizeof operand type '" << SizeofType.getAsString() << "'";
+ llvm::SmallVector<SourceRange, 4> Ranges;
+ Ranges.push_back(i->AllocCall->getCallee()->getSourceRange());
+ Ranges.push_back(SFinder.Sizeofs[0]->getSourceRange());
+ if (TSI)
+ Ranges.push_back(TSI->getTypeLoc().getSourceRange());
+
+ PathDiagnosticLocation L =
+ PathDiagnosticLocation::createBegin(i->AllocCall->getCallee(),
+ BR.getSourceManager(), ADC);
+
+ BR.EmitBasicReport("allocator sizeof operand mismatch", OS.str(), L,
+ Ranges.data(), Ranges.size());
+ }
+ }
+ }
+ }
+};
+
+}
+
+void ento::registerMallocSizeofChecker(CheckerManager &mgr) {
+ mgr.registerChecker<MallocSizeofChecker>();
+}
Added: cfe/trunk/test/Analysis/malloc-sizeof.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/malloc-sizeof.c?rev=146144&view=auto
==============================================================================
--- cfe/trunk/test/Analysis/malloc-sizeof.c (added)
+++ cfe/trunk/test/Analysis/malloc-sizeof.c Thu Dec 8 02:31:14 2011
@@ -0,0 +1,27 @@
+// RUN: %clang_cc1 -analyze -analyzer-checker=experimental.unix.MallocSizeof -verify %s
+
+#include <stddef.h>
+
+void *malloc(size_t size);
+void *calloc(size_t nmemb, size_t size);
+void *realloc(void *ptr, size_t size);
+
+struct A {};
+struct B {};
+
+void foo() {
+ int *ip1 = malloc(sizeof(1));
+ int *ip2 = malloc(4 * sizeof(int));
+
+ long *lp1 = malloc(sizeof(short)); // expected-warning {{Result of 'malloc' is converted to type 'long *', whose pointee type 'long' is incompatible with sizeof operand type 'short'}}
+ long *lp2 = malloc(5 * sizeof(double)); // expected-warning {{Result of 'malloc' is converted to type 'long *', whose pointee type 'long' is incompatible with sizeof operand type 'double'}}
+ long *lp3 = malloc(5 * sizeof(char) + 2); // expected-warning {{Result of 'malloc' is converted to type 'long *', whose pointee type 'long' is incompatible with sizeof operand type 'char'}}
+
+ struct A *ap1 = calloc(1, sizeof(struct A));
+ struct A *ap2 = calloc(2, sizeof(*ap1));
+ struct A *ap3 = calloc(2, sizeof(ap1)); // expected-warning {{Result of 'calloc' is converted to type 'struct A *', whose pointee type 'struct A' is incompatible with sizeof operand type 'struct A *'}}
+ struct A *ap4 = calloc(3, sizeof(struct A*)); // expected-warning {{Result of 'calloc' is converted to type 'struct A *', whose pointee type 'struct A' is incompatible with sizeof operand type 'struct A *'}}
+ struct A *ap5 = calloc(4, sizeof(struct B)); // expected-warning {{Result of 'calloc' is converted to type 'struct A *', whose pointee type 'struct A' is incompatible with sizeof operand type 'struct B'}}
+ struct A *ap6 = realloc(ap5, sizeof(struct A));
+ struct A *ap7 = realloc(ap5, sizeof(struct B)); // expected-warning {{Result of 'realloc' is converted to type 'struct A *', whose pointee type 'struct A' is incompatible with sizeof operand type 'struct B'}}
+}
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