[static analyzer] Extend VLA size checking to look for undefined sizes.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@60734 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/GRExprEngineInternalChecks.cpp b/lib/Analysis/GRExprEngineInternalChecks.cpp
index 8b484ab..d32318c 100644
--- a/lib/Analysis/GRExprEngineInternalChecks.cpp
+++ b/lib/Analysis/GRExprEngineInternalChecks.cpp
@@ -40,6 +40,7 @@
namespace {
class VISIBILITY_HIDDEN BuiltinBug : public BugTypeCacheLocation {
+protected:
const char* name;
const char* desc;
public:
@@ -332,26 +333,45 @@
}
};
-class VISIBILITY_HIDDEN ZeroSizeVLA : public BuiltinBug {
+class VISIBILITY_HIDDEN BadSizeVLA : public BuiltinBug {
public:
- ZeroSizeVLA() : BuiltinBug("Zero-sized VLA",
+ BadSizeVLA() : BuiltinBug("Zero-sized VLA",
"VLAs with zero-size are undefined.") {}
virtual void EmitBuiltinWarnings(BugReporter& BR, GRExprEngine& Eng) {
for (GRExprEngine::ErrorNodes::iterator
- I = Eng.ExplicitZeroSizedVLA.begin(),
- E = Eng.ExplicitZeroSizedVLA.end(); I!=E; ++I) {
-
- // Generate a report for this bug.
- PostStmt PS = cast<PostStmt>((*I)->getLocation());
+ I = Eng.ExplicitBadSizedVLA.begin(),
+ E = Eng.ExplicitBadSizedVLA.end(); I!=E; ++I) {
+
+ // Determine whether this was a 'zero-sized' VLA or a VLA with an
+ // undefined size.
+ GRExprEngine::NodeTy* N = *I;
+ PostStmt PS = cast<PostStmt>(N->getLocation());
DeclStmt *DS = cast<DeclStmt>(PS.getStmt());
VarDecl* VD = cast<VarDecl>(*DS->decl_begin());
QualType T = Eng.getContext().getCanonicalType(VD->getType());
VariableArrayType* VT = cast<VariableArrayType>(T);
+ Expr* SizeExpr = VT->getSizeExpr();
- RangedBugReport report(*this, *I);
- report.addRange(VT->getSizeExpr()->getSourceRange());
+ std::string buf;
+ llvm::raw_string_ostream os(buf);
+ os << "The expression used to specify the number of elements in the VLA '"
+ << VD->getNameAsString() << "' evaluates to ";
+
+ SVal X = Eng.getStateManager().GetSVal(N->getState(), SizeExpr);
+ if (X.isUndef()) {
+ name = "Undefined size for VLA";
+ os << "an undefined or garbage value.";
+ }
+ else {
+ name = "Zero-sized VLA";
+ os << " to 0. VLAs with no elements have undefined behavior.";
+ }
+
+ desc = os.str().c_str();
+ RangedBugReport report(*this, N);
+ report.addRange(SizeExpr->getSourceRange());
// Emit the warning.
BR.EmitWarning(report);
@@ -430,6 +450,6 @@
Register(new BadMsgExprArg());
Register(new BadReceiver());
Register(new OutOfBoundMemoryAccess());
- Register(new ZeroSizeVLA());
+ Register(new BadSizeVLA());
AddCheck(new CheckAttrNonNull(), Stmt::CallExprClass);
}