[analyzer] Malloc Checker: Report a leak when we are returning freed
memory.
(As per one test case, the existing checker thought that this could
cause a lot of false positives - not sure if that's valid, to be
verified.)
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@150313 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/StaticAnalyzer/Checkers/MallocChecker.cpp b/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
index d858959..ea4d7d2 100644
--- a/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
@@ -760,10 +760,16 @@
const Expr *E = S->getRetValue();
if (!E)
return;
+
+ // Check if we are returning a symbol.
SymbolRef Sym = C.getState()->getSVal(E, C.getLocationContext()).getAsSymbol();
if (!Sym)
return;
+ // Check if we are returning freed memory.
+ checkUseAfterFree(Sym, C, S);
+
+ // Check if the symbol is escaping.
checkEscape(Sym, S, C);
}
diff --git a/test/Analysis/malloc-annotations.c b/test/Analysis/malloc-annotations.c
index 7890cfc..98dc2e7 100644
--- a/test/Analysis/malloc-annotations.c
+++ b/test/Analysis/malloc-annotations.c
@@ -128,12 +128,10 @@
free(p); // no-warning
}
-// This case would inflict a double-free elsewhere.
-// However, this case is considered an analyzer bug since it causes false-positives.
int * af4() {
int *p = my_malloc(12);
my_free(p);
- return p; // no-warning
+ return p; // expected-warning{{Use of dynamically allocated}}
}
// This case is (possibly) ok, be conservative
diff --git a/test/Analysis/malloc.c b/test/Analysis/malloc.c
index 89299e6..b3095e0 100644
--- a/test/Analysis/malloc.c
+++ b/test/Analysis/malloc.c
@@ -251,6 +251,20 @@
struct StructWithInt {
int g;
};
+
+int *mallocReturnFreed() {
+ int *p = malloc(12);
+ free(p);
+ return p; // expected-warning {{Use of dynamically allocated}}
+}
+
+int useAfterFreeStruct() {
+ struct StructWithInt *px= malloc(sizeof(struct StructWithInt));
+ px->g = 5;
+ free(px);
+ return px->g; // expected-warning {{Use of dynamically allocated}}
+}
+
void nonSymbolAsFirstArg(int *pp, struct StructWithInt *p);
void mallocEscapeFooNonSymbolArg() {
