[analyzer] Be less pessimistic about invalidation of global variables
as a result of a call.
Problem:
Global variables, which come in from system libraries should not be
invalidated by all calls. Also, non-system globals should not be
invalidated by system calls.
Solution:
The following solution to invalidation of globals seems flexible enough
for taint (does not invalidate stdin) and should not lead to too
many false positives. We split globals into 3 classes:
* immutable - values are preserved by calls (unless the specific
global is passed in as a parameter):
A : Most system globals and const scalars
* invalidated by functions defined in system headers:
B: errno
* invalidated by all other functions (note, these functions may in
turn contain system calls):
B: errno
C: all other globals (which are not in A nor B)
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@147569 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/StaticAnalyzer/Checkers/MallocChecker.cpp b/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
index 3c7c907..dcc7ab9 100644
--- a/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
@@ -407,8 +407,7 @@
default: {
const MemSpaceRegion *MS = MR->getMemorySpace();
- switch (MS->getKind()) {
- case MemRegion::StackLocalsSpaceRegionKind: {
+ if (isa<StackLocalsSpaceRegion>(MS)) {
const VarRegion *VR = dyn_cast<VarRegion>(MR);
const VarDecl *VD;
if (VR)
@@ -422,7 +421,8 @@
os << "the address of a local stack variable";
return true;
}
- case MemRegion::StackArgumentsSpaceRegionKind: {
+
+ if (isa<StackArgumentsSpaceRegion>(MS)) {
const VarRegion *VR = dyn_cast<VarRegion>(MR);
const VarDecl *VD;
if (VR)
@@ -436,8 +436,8 @@
os << "the address of a parameter";
return true;
}
- case MemRegion::NonStaticGlobalSpaceRegionKind:
- case MemRegion::StaticGlobalSpaceRegionKind: {
+
+ if (isa<GlobalsSpaceRegion>(MS)) {
const VarRegion *VR = dyn_cast<VarRegion>(MR);
const VarDecl *VD;
if (VR)
@@ -454,9 +454,8 @@
os << "the address of a global variable";
return true;
}
- default:
- return false;
- }
+
+ return false;
}
}
}