[cfe-commits] r163066 - in /cfe/trunk: include/clang/StaticAnalyzer/Core/PathSensitive/BasicValueFactory.h include/clang/StaticAnalyzer/Core/PathSensitive/SVals.h lib/StaticAnalyzer/Core/RegionStore.cpp lib/StaticAnalyzer/Core/SymbolManager.cpp test/Analysis/array-struct-region.cpp test/Analysis/reference.cpp
Jordan Rose
jordan_rose at apple.com
Sat Sep 1 10:39:09 PDT 2012
Author: jrose
Date: Sat Sep 1 12:39:09 2012
New Revision: 163066
URL: http://llvm.org/viewvc/llvm-project?rev=163066&view=rev
Log:
[analyzer] Treat all struct values as regions (even rvalues).
This allows us to correctly symbolicate the fields of structs returned by
value, as well as get the proper 'this' value for when methods are called
on structs returned by value.
This does require a moderately ugly hack in the StoreManager: if we assign
a "struct value" to a struct region, that now appears as a Loc value being
bound to a region of struct type. We handle this by simply "dereferencing"
the struct value region, which should create a LazyCompoundVal.
This should fix recent crashes analyzing LLVM and on our internal buildbot.
<rdar://problem/12137950>
Added:
cfe/trunk/test/Analysis/array-struct-region.cpp
Modified:
cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/BasicValueFactory.h
cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/SVals.h
cfe/trunk/lib/StaticAnalyzer/Core/RegionStore.cpp
cfe/trunk/lib/StaticAnalyzer/Core/SymbolManager.cpp
cfe/trunk/test/Analysis/reference.cpp
Modified: cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/BasicValueFactory.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/BasicValueFactory.h?rev=163066&r1=163065&r2=163066&view=diff
==============================================================================
--- cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/BasicValueFactory.h (original)
+++ cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/BasicValueFactory.h Sat Sep 1 12:39:09 2012
@@ -90,6 +90,9 @@
/// Returns the type of the APSInt used to store values of the given QualType.
APSIntType getAPSIntType(QualType T) const {
assert(T->isIntegerType() || Loc::isLocType(T));
+ // Make sure all locations have the same representation in the analyzer.
+ if (Loc::isLocType(T))
+ T = Ctx.VoidPtrTy;
return APSIntType(Ctx.getTypeSize(T),
!T->isSignedIntegerOrEnumerationType());
}
Modified: cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/SVals.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/SVals.h?rev=163066&r1=163065&r2=163066&view=diff
==============================================================================
--- cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/SVals.h (original)
+++ cfe/trunk/include/clang/StaticAnalyzer/Core/PathSensitive/SVals.h Sat Sep 1 12:39:09 2012
@@ -246,8 +246,16 @@
}
static inline bool isLocType(QualType T) {
+ // Why are record types included here? Because we want to make sure a
+ // record, even a record rvalue, is always represented with a region.
+ // This is especially necessary in C++, where you can call methods on
+ // struct prvalues, which then need to have a valid 'this' pointer.
+ //
+ // This necessitates a bit of extra hackery in the Store to deal with
+ // the case of binding a "struct value" into a struct region; in
+ // practice it just means "dereferencing" the value before binding.
return T->isAnyPointerType() || T->isBlockPointerType() ||
- T->isReferenceType();
+ T->isReferenceType() || T->isRecordType();
}
};
Modified: cfe/trunk/lib/StaticAnalyzer/Core/RegionStore.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Core/RegionStore.cpp?rev=163066&r1=163065&r2=163066&view=diff
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Core/RegionStore.cpp (original)
+++ cfe/trunk/lib/StaticAnalyzer/Core/RegionStore.cpp Sat Sep 1 12:39:09 2012
@@ -1744,6 +1744,26 @@
if (!RD->isCompleteDefinition())
return StoreRef(store, *this);
+ // Handle Loc values by automatically dereferencing the location.
+ // This is necessary because we treat all struct values as regions even if
+ // they are rvalues; we may then be asked to bind one of these
+ // "rvalue regions" to an actual struct region.
+ // (This is necessary for many of the test cases in array-struct-region.cpp.)
+ //
+ // This also handles the case of a struct argument passed by value to an
+ // inlined function. In this case, the C++ standard says that the value
+ // is copy-constructed into the parameter variable. However, the copy-
+ // constructor is processed before we actually know if we're going to inline
+ // the function, and thus we don't actually have the parameter's region
+ // available. Instead, we use a temporary-object region, then copy the
+ // bindings over by value.
+ //
+ // FIXME: This will be a problem when we handle the destructors of
+ // temporaries; the inlined function will modify the parameter region,
+ // but the destructor will act on the temporary region.
+ if (const loc::MemRegionVal *MRV = dyn_cast<loc::MemRegionVal>(&V))
+ V = getBinding(store, *MRV);
+
// Handle lazy compound values and symbolic values.
if (isa<nonloc::LazyCompoundVal>(V) || isa<nonloc::SymbolVal>(V))
return BindAggregate(store, R, V);
Modified: cfe/trunk/lib/StaticAnalyzer/Core/SymbolManager.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Core/SymbolManager.cpp?rev=163066&r1=163065&r2=163066&view=diff
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Core/SymbolManager.cpp (original)
+++ cfe/trunk/lib/StaticAnalyzer/Core/SymbolManager.cpp Sat Sep 1 12:39:09 2012
@@ -365,9 +365,6 @@
if (T->isIntegerType())
return T->isScalarType();
- if (T->isRecordType() && !T->isUnionType())
- return true;
-
return false;
}
Added: cfe/trunk/test/Analysis/array-struct-region.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/array-struct-region.cpp?rev=163066&view=auto
==============================================================================
--- cfe/trunk/test/Analysis/array-struct-region.cpp (added)
+++ cfe/trunk/test/Analysis/array-struct-region.cpp Sat Sep 1 12:39:09 2012
@@ -0,0 +1,87 @@
+// RUN: %clang_cc1 -analyze -analyzer-checker=core,alpha.core,debug.ExprInspection -verify -x c %s
+// RUN: %clang_cc1 -analyze -analyzer-checker=core,alpha.core,debug.ExprInspection -verify -x c++ -analyzer-config c++-inlining=constructors %s
+
+void clang_analyzer_eval(int);
+
+struct S {
+ int field;
+
+#if __cplusplus
+ const struct S *getThis() const { return this; }
+#endif
+};
+
+struct S getS();
+
+
+void testAssignment() {
+ struct S s = getS();
+
+ if (s.field != 42) return;
+ clang_analyzer_eval(s.field == 42); // expected-warning{{TRUE}}
+
+ s.field = 0;
+ clang_analyzer_eval(s.field == 0); // expected-warning{{TRUE}}
+
+#if __cplusplus
+ clang_analyzer_eval(s.getThis() == &s); // expected-warning{{TRUE}}
+#endif
+}
+
+
+void testImmediateUse() {
+ int x = getS().field;
+
+ if (x != 42) return;
+ clang_analyzer_eval(x == 42); // expected-warning{{TRUE}}
+
+#if __cplusplus
+ clang_analyzer_eval((void *)getS().getThis() == (void *)&x); // expected-warning{{FALSE}}
+#endif
+}
+
+int getConstrainedField(struct S s) {
+ if (s.field != 42) return 42;
+ return s.field;
+}
+
+int getAssignedField(struct S s) {
+ s.field = 42;
+ return s.field;
+}
+
+void testArgument() {
+ clang_analyzer_eval(getConstrainedField(getS()) == 42); // expected-warning{{TRUE}}
+ clang_analyzer_eval(getAssignedField(getS()) == 42); // expected-warning{{TRUE}}
+}
+
+
+//--------------------
+// C++-only tests
+//--------------------
+
+#if __cplusplus
+void testReferenceAssignment() {
+ const S &s = getS();
+
+ if (s.field != 42) return;
+ clang_analyzer_eval(s.field == 42); // expected-warning{{TRUE}}
+
+ clang_analyzer_eval(s.getThis() == &s); // expected-warning{{TRUE}}
+}
+
+
+int getConstrainedFieldRef(const S &s) {
+ if (s.field != 42) return 42;
+ return s.field;
+}
+
+bool checkThis(const S &s) {
+ return s.getThis() == &s;
+}
+
+void testReferenceArgument() {
+ clang_analyzer_eval(getConstrainedFieldRef(getS()) == 42); // expected-warning{{TRUE}}
+ clang_analyzer_eval(checkThis(getS())); // expected-warning{{TRUE}}
+}
+#endif
Modified: cfe/trunk/test/Analysis/reference.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/reference.cpp?rev=163066&r1=163065&r2=163066&view=diff
==============================================================================
--- cfe/trunk/test/Analysis/reference.cpp (original)
+++ cfe/trunk/test/Analysis/reference.cpp Sat Sep 1 12:39:09 2012
@@ -116,8 +116,11 @@
struct S { int &x; };
- extern S *getS();
- clang_analyzer_eval(&getS()->x != 0); // expected-warning{{TRUE}}
+ extern S getS();
+ clang_analyzer_eval(&getS().x != 0); // expected-warning{{TRUE}}
+
+ extern S *getSP();
+ clang_analyzer_eval(&getSP()->x != 0); // expected-warning{{TRUE}}
}
@@ -150,10 +153,3 @@
return *x; // should warn here!
}
}
-
-void testReferenceFieldAddress() {
- struct S { int &x; };
-
- extern S getS();
- clang_analyzer_eval(&getS().x != 0); // expected-warning{{UNKNOWN}}
-}
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