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authorpascal <pascal@openbsd.org>2016-09-03 22:46:54 +0000
committerpascal <pascal@openbsd.org>2016-09-03 22:46:54 +0000
commitb5500b9ca0102f1ccaf32f0e77e96d0739aded9b (patch)
treee1b7ebb5a0231f9e6d8d3f6f719582cebd64dc98 /gnu/llvm/tools/clang/lib/StaticAnalyzer/Checkers/CheckSizeofPointer.cpp
parentclarify purpose of src/gnu/ directory. (diff)
downloadwireguard-openbsd-b5500b9ca0102f1ccaf32f0e77e96d0739aded9b.tar.xz
wireguard-openbsd-b5500b9ca0102f1ccaf32f0e77e96d0739aded9b.zip
Use the space freed up by sparc and zaurus to import LLVM.
ok hackroom@
Diffstat (limited to 'gnu/llvm/tools/clang/lib/StaticAnalyzer/Checkers/CheckSizeofPointer.cpp')
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diff --git a/gnu/llvm/tools/clang/lib/StaticAnalyzer/Checkers/CheckSizeofPointer.cpp b/gnu/llvm/tools/clang/lib/StaticAnalyzer/Checkers/CheckSizeofPointer.cpp
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+++ b/gnu/llvm/tools/clang/lib/StaticAnalyzer/Checkers/CheckSizeofPointer.cpp
@@ -0,0 +1,93 @@
+//==- CheckSizeofPointer.cpp - Check for sizeof on pointers ------*- 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 check for unintended use of sizeof() on pointer
+// expressions.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ClangSACheckers.h"
+#include "clang/AST/StmtVisitor.h"
+#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
+#include "clang/StaticAnalyzer/Core/Checker.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
+
+using namespace clang;
+using namespace ento;
+
+namespace {
+class WalkAST : public StmtVisitor<WalkAST> {
+ BugReporter &BR;
+ const CheckerBase *Checker;
+ AnalysisDeclContext* AC;
+
+public:
+ WalkAST(BugReporter &br, const CheckerBase *checker, AnalysisDeclContext *ac)
+ : BR(br), Checker(checker), AC(ac) {}
+ void VisitUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *E);
+ void VisitStmt(Stmt *S) { VisitChildren(S); }
+ void VisitChildren(Stmt *S);
+};
+}
+
+void WalkAST::VisitChildren(Stmt *S) {
+ for (Stmt *Child : S->children())
+ if (Child)
+ Visit(Child);
+}
+
+// CWE-467: Use of sizeof() on a Pointer Type
+void WalkAST::VisitUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *E) {
+ if (E->getKind() != UETT_SizeOf)
+ return;
+
+ // If an explicit type is used in the code, usually the coder knows what they are
+ // doing.
+ if (E->isArgumentType())
+ return;
+
+ QualType T = E->getTypeOfArgument();
+ if (T->isPointerType()) {
+
+ // Many false positives have the form 'sizeof *p'. This is reasonable
+ // because people know what they are doing when they intentionally
+ // dereference the pointer.
+ Expr *ArgEx = E->getArgumentExpr();
+ if (!isa<DeclRefExpr>(ArgEx->IgnoreParens()))
+ return;
+
+ PathDiagnosticLocation ELoc =
+ PathDiagnosticLocation::createBegin(E, BR.getSourceManager(), AC);
+ BR.EmitBasicReport(AC->getDecl(), Checker,
+ "Potential unintended use of sizeof() on pointer type",
+ categories::LogicError,
+ "The code calls sizeof() on a pointer type. "
+ "This can produce an unexpected result.",
+ ELoc, ArgEx->getSourceRange());
+ }
+}
+
+//===----------------------------------------------------------------------===//
+// SizeofPointerChecker
+//===----------------------------------------------------------------------===//
+
+namespace {
+class SizeofPointerChecker : public Checker<check::ASTCodeBody> {
+public:
+ void checkASTCodeBody(const Decl *D, AnalysisManager& mgr,
+ BugReporter &BR) const {
+ WalkAST walker(BR, this, mgr.getAnalysisDeclContext(D));
+ walker.Visit(D->getBody());
+ }
+};
+}
+
+void ento::registerSizeofPointerChecker(CheckerManager &mgr) {
+ mgr.registerChecker<SizeofPointerChecker>();
+}