forked from OSchip/llvm-project
72 lines
2.2 KiB
C++
72 lines
2.2 KiB
C++
//==- CheckSizeofPointer.cpp - Check for sizeof on pointers ------*- 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 file defines a check for unintended use of sizeof() on pointer
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// expressions.
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//
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//===----------------------------------------------------------------------===//
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#include "clang/Checker/BugReporter/BugReporter.h"
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#include "clang/AST/StmtVisitor.h"
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#include "clang/Checker/Checkers/LocalCheckers.h"
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using namespace clang;
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namespace {
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class WalkAST : public StmtVisitor<WalkAST> {
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BugReporter &BR;
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public:
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WalkAST(BugReporter &br) : BR(br) {}
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void VisitSizeOfAlignOfExpr(SizeOfAlignOfExpr *E);
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void VisitStmt(Stmt *S) { VisitChildren(S); }
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void VisitChildren(Stmt *S);
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};
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}
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void WalkAST::VisitChildren(Stmt *S) {
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for (Stmt::child_iterator I = S->child_begin(), E = S->child_end(); I!=E; ++I)
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if (Stmt *child = *I)
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Visit(child);
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}
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// CWE-467: Use of sizeof() on a Pointer Type
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void WalkAST::VisitSizeOfAlignOfExpr(SizeOfAlignOfExpr *E) {
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if (!E->isSizeOf())
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return;
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// If an explicit type is used in the code, usually the coder knows what he is
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// doing.
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if (E->isArgumentType())
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return;
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QualType T = E->getTypeOfArgument();
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if (T->isPointerType()) {
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// Many false positives have the form 'sizeof *p'. This is reasonable
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// because people know what they are doing when they intentionally
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// dereference the pointer.
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Expr *ArgEx = E->getArgumentExpr();
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if (!isa<DeclRefExpr>(ArgEx->IgnoreParens()))
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return;
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SourceRange R = ArgEx->getSourceRange();
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BR.EmitBasicReport("Potential unintended use of sizeof() on pointer type",
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"Logic",
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"The code calls sizeof() on a pointer type. "
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"This can produce an unexpected result.",
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E->getLocStart(), &R, 1);
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}
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}
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void clang::CheckSizeofPointer(const Decl *D, BugReporter &BR) {
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WalkAST walker(BR);
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walker.Visit(D->getBody());
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}
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