forked from OSchip/llvm-project
76 lines
2.3 KiB
C++
76 lines
2.3 KiB
C++
//=== BuiltinFunctionChecker.cpp --------------------------------*- C++ -*-===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This checker evaluates clang builtin functions.
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//
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//===----------------------------------------------------------------------===//
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#include "GRExprEngineInternalChecks.h"
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#include "clang/Checker/PathSensitive/Checker.h"
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#include "clang/Basic/Builtins.h"
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using namespace clang;
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namespace {
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class BuiltinFunctionChecker : public Checker {
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public:
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static void *getTag() { static int tag = 0; return &tag; }
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virtual bool EvalCallExpr(CheckerContext &C, const CallExpr *CE);
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};
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}
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void clang::RegisterBuiltinFunctionChecker(GRExprEngine &Eng) {
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Eng.registerCheck(new BuiltinFunctionChecker());
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}
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bool BuiltinFunctionChecker::EvalCallExpr(CheckerContext &C,const CallExpr *CE){
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const GRState *state = C.getState();
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const Expr *Callee = CE->getCallee();
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SVal L = state->getSVal(Callee);
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const FunctionDecl *FD = L.getAsFunctionDecl();
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if (!FD)
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return false;
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unsigned id = FD->getBuiltinID();
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if (!id)
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return false;
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switch (id) {
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case Builtin::BI__builtin_expect: {
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// For __builtin_expect, just return the value of the subexpression.
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assert (CE->arg_begin() != CE->arg_end());
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SVal X = state->getSVal(*(CE->arg_begin()));
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C.GenerateNode(state->BindExpr(CE, X));
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return true;
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}
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case Builtin::BI__builtin_alloca: {
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// FIXME: Refactor into StoreManager itself?
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MemRegionManager& RM = C.getStoreManager().getRegionManager();
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const MemRegion* R =
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RM.getAllocaRegion(CE, C.getNodeBuilder().getCurrentBlockCount(),
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C.getPredecessor()->getLocationContext());
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// Set the extent of the region in bytes. This enables us to use the
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// SVal of the argument directly. If we save the extent in bits, we
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// cannot represent values like symbol*8.
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SVal Extent = state->getSVal(*(CE->arg_begin()));
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state = C.getStoreManager().setExtent(state, R, Extent);
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C.GenerateNode(state->BindExpr(CE, loc::MemRegionVal(R)));
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return true;
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}
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}
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return false;
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}
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