Fix assertion failure in -Wuninitialized involving no-op casts. Fixes PR 10577.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@136939 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Ted Kremenek 2011-08-04 22:40:57 +00:00
Родитель 62a811d171
Коммит 57fb591a54
2 изменённых файлов: 30 добавлений и 5 удалений

Просмотреть файл

@ -352,13 +352,19 @@ class TransferFunctions : public StmtVisitor<TransferFunctions> {
/// possible to either silence the warning in some cases, or we
/// propagate the uninitialized value.
CastExpr *lastLoad;
/// For some expressions, we want to ignore any post-processing after
/// visitation.
bool skipProcessUses;
public:
TransferFunctions(CFGBlockValues &vals, const CFG &cfg,
AnalysisContext &ac,
UninitVariablesHandler *handler,
bool flagBlockUses)
: vals(vals), cfg(cfg), ac(ac), handler(handler),
flagBlockUses(flagBlockUses), lastDR(0), lastLoad(0) {}
flagBlockUses(flagBlockUses), lastDR(0), lastLoad(0),
skipProcessUses(false) {}
const CFG &getCFG() { return cfg; }
void reportUninit(const DeclRefExpr *ex, const VarDecl *vd,
@ -464,8 +470,9 @@ void TransferFunctions::VisitDeclStmt(DeclStmt *ds) {
// appropriately, but we need to continue to analyze subsequent uses
// of the variable.
if (init == lastLoad) {
DeclRefExpr *DR =
cast<DeclRefExpr>(lastLoad->getSubExpr()->IgnoreParens());
DeclRefExpr *DR
= cast<DeclRefExpr>(lastLoad->
getSubExpr()->IgnoreParenNoopCasts(ac.getASTContext()));
if (DR->getDecl() == vd) {
// int x = x;
// Propagate uninitialized value, but don't immediately report
@ -537,6 +544,9 @@ void TransferFunctions::VisitCastExpr(clang::CastExpr *ce) {
}
}
}
else if (ce->getCastKind() == CK_NoOp) {
skipProcessUses = true;
}
else if (CStyleCastExpr *cse = dyn_cast<CStyleCastExpr>(ce)) {
if (cse->getType()->isVoidType()) {
// e.g. (void) x;
@ -551,8 +561,10 @@ void TransferFunctions::VisitCastExpr(clang::CastExpr *ce) {
}
void TransferFunctions::Visit(clang::Stmt *s) {
skipProcessUses = false;
StmtVisitor<TransferFunctions>::Visit(s);
ProcessUses(s);
if (!skipProcessUses)
ProcessUses(s);
}
void TransferFunctions::ProcessUses(Stmt *s) {
@ -568,7 +580,9 @@ void TransferFunctions::ProcessUses(Stmt *s) {
// If we reach here, we have seen a load of an uninitialized value
// and it hasn't been casted to void or otherwise handled. In this
// situation, report the incident.
DeclRefExpr *DR = cast<DeclRefExpr>(lastLoad->getSubExpr()->IgnoreParens());
DeclRefExpr *DR =
cast<DeclRefExpr>(lastLoad->getSubExpr()->
IgnoreParenNoopCasts(ac.getASTContext()));
VarDecl *VD = cast<VarDecl>(DR->getDecl());
reportUninit(DR, VD, isAlwaysUninit(vals[VD]));
lastLoad = 0;

Просмотреть файл

@ -118,4 +118,15 @@ void RDar9251392() {
}
}
// Test handling of "no-op" casts.
void test_noop_cast()
{
int x = 1;
int y = (int&)x; // no-warning
}
void test_noop_cast2() {
int x; // expected-note {{declared here}} expected-note {{add initialization}}
int y = (int&)x; // expected-warning {{uninitialized when used here}}
}