-Wuninitialized: assume that an __attribute__((returns_twice)) function might
initialize any variable. This is extremely conservative, but is sufficient for
now.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159620 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/UninitializedValues.cpp b/lib/Analysis/UninitializedValues.cpp
index fbfa46c..1f97c58 100644
--- a/lib/Analysis/UninitializedValues.cpp
+++ b/lib/Analysis/UninitializedValues.cpp
@@ -116,6 +116,7 @@
BVPair &getValueVectors(const CFGBlock *block, bool shouldLazyCreate);
+ void setAllScratchValues(Value V);
void mergeIntoScratch(ValueVector const &source, bool isFirst);
bool updateValueVectorWithScratch(const CFGBlock *block);
bool updateValueVectors(const CFGBlock *block, const BVPair &newVals);
@@ -240,6 +241,11 @@
}
#endif
+void CFGBlockValues::setAllScratchValues(Value V) {
+ for (unsigned I = 0, E = scratch.size(); I != E; ++I)
+ scratch[I] = V;
+}
+
void CFGBlockValues::mergeIntoScratch(ValueVector const &source,
bool isFirst) {
if (isFirst)
@@ -374,6 +380,7 @@
void reportUse(const Expr *ex, const VarDecl *vd);
void VisitBlockExpr(BlockExpr *be);
+ void VisitCallExpr(CallExpr *ce);
void VisitDeclStmt(DeclStmt *ds);
void VisitDeclRefExpr(DeclRefExpr *dr);
void VisitUnaryOperator(UnaryOperator *uo);
@@ -576,6 +583,17 @@
}
}
+void TransferFunctions::VisitCallExpr(CallExpr *ce) {
+ // After a call to a function like setjmp or vfork, any variable which is
+ // initialized anywhere within this function may now be initialized. For now,
+ // just assume such a call initializes all variables.
+ // FIXME: Only mark variables as initialized if they have an initializer which
+ // is reachable from here.
+ Decl *Callee = ce->getCalleeDecl();
+ if (Callee && Callee->hasAttr<ReturnsTwiceAttr>())
+ vals.setAllScratchValues(Initialized);
+}
+
void TransferFunctions::VisitDeclRefExpr(DeclRefExpr *dr) {
// Record the last DeclRefExpr seen. This is an lvalue computation.
// We use this value to later detect if a variable "escapes" the analysis.