Files
clang-p2996/clang/lib/StaticAnalyzer/Checkers/UndefCapturedBlockVarChecker.cpp
Kristof Umann 76a21502fd [analyzer][NFC] Move CheckerRegistry from the Core directory to Frontend
ClangCheckerRegistry is a very non-obvious, poorly documented, weird concept.
It derives from CheckerRegistry, and is placed in lib/StaticAnalyzer/Frontend,
whereas it's base is located in lib/StaticAnalyzer/Core. It was, from what I can
imagine, used to circumvent the problem that the registry functions of the
checkers are located in the clangStaticAnalyzerCheckers library, but that
library depends on clangStaticAnalyzerCore. However, clangStaticAnalyzerFrontend
depends on both of those libraries.

One can make the observation however, that CheckerRegistry has no place in Core,
it isn't used there at all! The only place where it is used is Frontend, which
is where it ultimately belongs.

This move implies that since
include/clang/StaticAnalyzer/Checkers/ClangCheckers.h only contained a single function:

class CheckerRegistry;

void registerBuiltinCheckers(CheckerRegistry &registry);

it had to re purposed, as CheckerRegistry is no longer available to
clangStaticAnalyzerCheckers. It was renamed to BuiltinCheckerRegistration.h,
which actually describes it a lot better -- it does not contain the registration
functions for checkers, but only those generated by the tblgen files.

Differential Revision: https://reviews.llvm.org/D54436

llvm-svn: 349275
2018-12-15 16:23:51 +00:00

103 lines
3.5 KiB
C++

// UndefCapturedBlockVarChecker.cpp - Uninitialized captured vars -*- C++ -*-=//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This checker detects blocks that capture uninitialized values.
//
//===----------------------------------------------------------------------===//
#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
#include "clang/AST/Attr.h"
#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
#include "clang/StaticAnalyzer/Core/Checker.h"
#include "clang/StaticAnalyzer/Core/CheckerManager.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/raw_ostream.h"
using namespace clang;
using namespace ento;
namespace {
class UndefCapturedBlockVarChecker
: public Checker< check::PostStmt<BlockExpr> > {
mutable std::unique_ptr<BugType> BT;
public:
void checkPostStmt(const BlockExpr *BE, CheckerContext &C) const;
};
} // end anonymous namespace
static const DeclRefExpr *FindBlockDeclRefExpr(const Stmt *S,
const VarDecl *VD) {
if (const DeclRefExpr *BR = dyn_cast<DeclRefExpr>(S))
if (BR->getDecl() == VD)
return BR;
for (const Stmt *Child : S->children())
if (Child)
if (const DeclRefExpr *BR = FindBlockDeclRefExpr(Child, VD))
return BR;
return nullptr;
}
void
UndefCapturedBlockVarChecker::checkPostStmt(const BlockExpr *BE,
CheckerContext &C) const {
if (!BE->getBlockDecl()->hasCaptures())
return;
ProgramStateRef state = C.getState();
auto *R = cast<BlockDataRegion>(C.getSVal(BE).getAsRegion());
BlockDataRegion::referenced_vars_iterator I = R->referenced_vars_begin(),
E = R->referenced_vars_end();
for (; I != E; ++I) {
// This VarRegion is the region associated with the block; we need
// the one associated with the encompassing context.
const VarRegion *VR = I.getCapturedRegion();
const VarDecl *VD = VR->getDecl();
if (VD->hasAttr<BlocksAttr>() || !VD->hasLocalStorage())
continue;
// Get the VarRegion associated with VD in the local stack frame.
if (Optional<UndefinedVal> V =
state->getSVal(I.getOriginalRegion()).getAs<UndefinedVal>()) {
if (ExplodedNode *N = C.generateErrorNode()) {
if (!BT)
BT.reset(
new BuiltinBug(this, "uninitialized variable captured by block"));
// Generate a bug report.
SmallString<128> buf;
llvm::raw_svector_ostream os(buf);
os << "Variable '" << VD->getName()
<< "' is uninitialized when captured by block";
auto R = llvm::make_unique<BugReport>(*BT, os.str(), N);
if (const Expr *Ex = FindBlockDeclRefExpr(BE->getBody(), VD))
R->addRange(Ex->getSourceRange());
R->addVisitor(llvm::make_unique<FindLastStoreBRVisitor>(
*V, VR, /*EnableNullFPSuppression*/ false));
R->disablePathPruning();
// need location of block
C.emitReport(std::move(R));
}
}
}
}
void ento::registerUndefCapturedBlockVarChecker(CheckerManager &mgr) {
mgr.registerChecker<UndefCapturedBlockVarChecker>();
}