132 lines
4.5 KiB
C++
132 lines
4.5 KiB
C++
//== CheckerContext.cpp - Context info for path-sensitive checkers-----------=//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file defines CheckerContext that provides contextual info for
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// path-sensitive checkers.
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//
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//===----------------------------------------------------------------------===//
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#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
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#include "clang/Basic/Builtins.h"
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#include "clang/Lex/Lexer.h"
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using namespace clang;
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using namespace ento;
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const FunctionDecl *CheckerContext::getCalleeDecl(const CallExpr *CE) const {
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const Expr *Callee = CE->getCallee();
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SVal L = Pred->getSVal(Callee);
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return L.getAsFunctionDecl();
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}
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StringRef CheckerContext::getCalleeName(const FunctionDecl *FunDecl) const {
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if (!FunDecl)
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return StringRef();
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IdentifierInfo *funI = FunDecl->getIdentifier();
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if (!funI)
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return StringRef();
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return funI->getName();
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}
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StringRef CheckerContext::getDeclDescription(const Decl *D) {
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if (isa<ObjCMethodDecl>(D) || isa<CXXMethodDecl>(D))
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return "method";
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if (isa<BlockDecl>(D))
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return "anonymous block";
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return "function";
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}
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bool CheckerContext::isCLibraryFunction(const FunctionDecl *FD,
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StringRef Name) {
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// To avoid false positives (Ex: finding user defined functions with
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// similar names), only perform fuzzy name matching when it's a builtin.
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// Using a string compare is slow, we might want to switch on BuiltinID here.
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unsigned BId = FD->getBuiltinID();
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if (BId != 0) {
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if (Name.empty())
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return true;
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StringRef BName = FD->getASTContext().BuiltinInfo.getName(BId);
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if (BName.find(Name) != StringRef::npos)
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return true;
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}
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const IdentifierInfo *II = FD->getIdentifier();
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// If this is a special C++ name without IdentifierInfo, it can't be a
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// C library function.
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if (!II)
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return false;
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// Look through 'extern "C"' and anything similar invented in the future.
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// If this function is not in TU directly, it is not a C library function.
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if (!FD->getDeclContext()->getRedeclContext()->isTranslationUnit())
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return false;
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// If this function is not externally visible, it is not a C library function.
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// Note that we make an exception for inline functions, which may be
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// declared in header files without external linkage.
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if (!FD->isInlined() && !FD->isExternallyVisible())
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return false;
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if (Name.empty())
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return true;
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StringRef FName = II->getName();
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if (FName.equals(Name))
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return true;
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if (FName.startswith("__inline") && (FName.find(Name) != StringRef::npos))
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return true;
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if (FName.startswith("__") && FName.endswith("_chk") &&
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FName.find(Name) != StringRef::npos)
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return true;
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return false;
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}
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StringRef CheckerContext::getMacroNameOrSpelling(SourceLocation &Loc) {
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if (Loc.isMacroID())
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return Lexer::getImmediateMacroName(Loc, getSourceManager(),
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getLangOpts());
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SmallVector<char, 16> buf;
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return Lexer::getSpelling(Loc, buf, getSourceManager(), getLangOpts());
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}
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/// Evaluate comparison and return true if it's known that condition is true
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static bool evalComparison(SVal LHSVal, BinaryOperatorKind ComparisonOp,
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SVal RHSVal, ProgramStateRef State) {
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if (LHSVal.isUnknownOrUndef())
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return false;
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ProgramStateManager &Mgr = State->getStateManager();
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if (!LHSVal.getAs<NonLoc>()) {
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LHSVal = Mgr.getStoreManager().getBinding(State->getStore(),
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LHSVal.castAs<Loc>());
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if (LHSVal.isUnknownOrUndef() || !LHSVal.getAs<NonLoc>())
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return false;
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}
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SValBuilder &Bldr = Mgr.getSValBuilder();
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SVal Eval = Bldr.evalBinOp(State, ComparisonOp, LHSVal, RHSVal,
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Bldr.getConditionType());
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if (Eval.isUnknownOrUndef())
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return false;
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ProgramStateRef StTrue, StFalse;
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std::tie(StTrue, StFalse) = State->assume(Eval.castAs<DefinedSVal>());
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return StTrue && !StFalse;
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}
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bool CheckerContext::isGreaterOrEqual(const Expr *E, unsigned long long Val) {
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DefinedSVal V = getSValBuilder().makeIntVal(Val, getASTContext().LongLongTy);
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return evalComparison(getSVal(E), BO_GE, V, getState());
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}
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bool CheckerContext::isNegative(const Expr *E) {
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DefinedSVal V = getSValBuilder().makeIntVal(0, false);
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return evalComparison(getSVal(E), BO_LT, V, getState());
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}
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