[analyzer] Detect pointers escaped after ReturnStmt execution in MallocChecker.
Objects local to a function are destroyed right after the statement returning
(part of) them is executed in the analyzer. This patch enables MallocChecker to
warn in these cases.
Differential Revision: https://reviews.llvm.org/D49361
llvm-svn: 338780
diff --git a/clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
index ebaf79a..3ac7105 100644
--- a/clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
@@ -161,6 +161,7 @@
check::PointerEscape,
check::ConstPointerEscape,
check::PreStmt<ReturnStmt>,
+ check::EndFunction,
check::PreCall,
check::PostStmt<CallExpr>,
check::PostStmt<CXXNewExpr>,
@@ -217,6 +218,7 @@
void checkPostStmt(const BlockExpr *BE, CheckerContext &C) const;
void checkDeadSymbols(SymbolReaper &SymReaper, CheckerContext &C) const;
void checkPreStmt(const ReturnStmt *S, CheckerContext &C) const;
+ void checkEndFunction(const ReturnStmt *S, CheckerContext &C) const;
ProgramStateRef evalAssume(ProgramStateRef state, SVal Cond,
bool Assumption) const;
void checkLocation(SVal l, bool isLoad, const Stmt *S,
@@ -353,7 +355,7 @@
static ProgramStateRef CallocMem(CheckerContext &C, const CallExpr *CE,
ProgramStateRef State);
- ///Check if the memory associated with this symbol was released.
+ /// Check if the memory associated with this symbol was released.
bool isReleased(SymbolRef Sym, CheckerContext &C) const;
bool checkUseAfterFree(SymbolRef Sym, CheckerContext &C, const Stmt *S) const;
@@ -377,13 +379,16 @@
ProgramStateRef State,
SymbolRef &EscapingSymbol) const;
- // Implementation of the checkPointerEscape callabcks.
+ // Implementation of the checkPointerEscape callbacks.
ProgramStateRef checkPointerEscapeAux(ProgramStateRef State,
const InvalidatedSymbols &Escaped,
const CallEvent *Call,
PointerEscapeKind Kind,
bool(*CheckRefState)(const RefState*)) const;
+ // Implementation of the checkPreStmt and checkEndFunction callbacks.
+ void checkEscapeOnReturn(const ReturnStmt *S, CheckerContext &C) const;
+
///@{
/// Tells if a given family/call/symbol is tracked by the current checker.
/// Sets CheckKind to the kind of the checker responsible for this
@@ -2451,7 +2456,24 @@
}
}
-void MallocChecker::checkPreStmt(const ReturnStmt *S, CheckerContext &C) const {
+void MallocChecker::checkPreStmt(const ReturnStmt *S,
+ CheckerContext &C) const {
+ checkEscapeOnReturn(S, C);
+}
+
+// In the CFG, automatic destructors come after the return statement.
+// This callback checks for returning memory that is freed by automatic
+// destructors, as those cannot be reached in checkPreStmt().
+void MallocChecker::checkEndFunction(const ReturnStmt *S,
+ CheckerContext &C) const {
+ checkEscapeOnReturn(S, C);
+}
+
+void MallocChecker::checkEscapeOnReturn(const ReturnStmt *S,
+ CheckerContext &C) const {
+ if (!S)
+ return;
+
const Expr *E = S->getRetValue();
if (!E)
return;