NoQ created this revision.
pr34404 points out that given
class C {
struct {
int x;
};
};
, taking pointer-to-member `&C::x` would crash the analyzer. We were not ready
to stumble upon an `IndirectFieldDecl`, which is used for representing a field
within an anonymous structure (or union) nested into a class.
Even if it wasn't anonymous, our new pointer-to-member support is not yet
enabled for this case, so the value of the expression would be a conjured
symbol of type `void *`. Being quite vague, it fits equally poorly to the
anonymous case (in general this behavior makes very little sense, since
//pointer-to-member must be a `NonLoc`//), so for the purposes of fixing the
crash i guess i'd just keep it.
Actually constructing a `nonloc::PointerToMember` in the regular field case
should be trivial. However, in the anonymous field case it requires more work,
because `IndirectFieldDecl` is not a `DeclaratorDecl`. And simply calling
`getAnonField()` over `IndirectFieldDecl` to obtain `FieldDecl` is incorrect,
because it'd discard the offset to the anonymous structure within the class,
leading to incorrect results on the attached tests for `m` and `n`.
https://reviews.llvm.org/D39800
Files:
lib/StaticAnalyzer/Core/ExprEngine.cpp
test/Analysis/pointer-to-member.cpp
Index: test/Analysis/pointer-to-member.cpp
===================================================================
--- test/Analysis/pointer-to-member.cpp
+++ test/Analysis/pointer-to-member.cpp
@@ -230,3 +230,42 @@
clang_analyzer_eval(d2.*(static_cast<int D2::*>(static_cast<int
R2::*>(static_cast<int R1::*>(&B::f)))) == 4); // expected-warning {{TRUE}}
}
} // end of testPointerToMemberDiamond namespace
+
+namespace testAnonymousMember {
+struct A {
+ struct {
+ int x;
+ };
+ struct {
+ struct {
+ int y;
+ };
+ };
+ struct {
+ union {
+ int z;
+ };
+ };
+};
+
+void test() {
+ clang_analyzer_eval(&A::x); // expected-warning{{TRUE}}
+ clang_analyzer_eval(&A::y); // expected-warning{{TRUE}}
+ clang_analyzer_eval(&A::z); // expected-warning{{TRUE}}
+
+ // FIXME: These should be true.
+ int A::*l = &A::x, A::*m = &A::y, A::*n = &A::z;
+ clang_analyzer_eval(l); // expected-warning{{UNKNOWN}}
+ clang_analyzer_eval(m); // expected-warning{{UNKNOWN}}
+ clang_analyzer_eval(n); // expected-warning{{UNKNOWN}}
+
+ // FIXME: These should be true as well.
+ A a;
+ a.x = 1;
+ clang_analyzer_eval(a.*l == 1); // expected-warning{{UNKNOWN}}
+ a.y = 2;
+ clang_analyzer_eval(a.*m == 2); // expected-warning{{UNKNOWN}}
+ a.z = 3;
+ clang_analyzer_eval(a.*n == 3); // expected-warning{{UNKNOWN}}
+}
+} // end of testAnonymousMember namespace
Index: lib/StaticAnalyzer/Core/ExprEngine.cpp
===================================================================
--- lib/StaticAnalyzer/Core/ExprEngine.cpp
+++ lib/StaticAnalyzer/Core/ExprEngine.cpp
@@ -2108,7 +2108,7 @@
ProgramPoint::PostLValueKind);
return;
}
- if (isa<FieldDecl>(D)) {
+ if (isa<FieldDecl>(D) || isa<IndirectFieldDecl>(D)) {
// FIXME: Compute lvalue of field pointers-to-member.
// Right now we just use a non-null void pointer, so that it gives proper
// results in boolean contexts.
Index: test/Analysis/pointer-to-member.cpp
===================================================================
--- test/Analysis/pointer-to-member.cpp
+++ test/Analysis/pointer-to-member.cpp
@@ -230,3 +230,42 @@
clang_analyzer_eval(d2.*(static_cast<int D2::*>(static_cast<int R2::*>(static_cast<int R1::*>(&B::f)))) == 4); // expected-warning {{TRUE}}
}
} // end of testPointerToMemberDiamond namespace
+
+namespace testAnonymousMember {
+struct A {
+ struct {
+ int x;
+ };
+ struct {
+ struct {
+ int y;
+ };
+ };
+ struct {
+ union {
+ int z;
+ };
+ };
+};
+
+void test() {
+ clang_analyzer_eval(&A::x); // expected-warning{{TRUE}}
+ clang_analyzer_eval(&A::y); // expected-warning{{TRUE}}
+ clang_analyzer_eval(&A::z); // expected-warning{{TRUE}}
+
+ // FIXME: These should be true.
+ int A::*l = &A::x, A::*m = &A::y, A::*n = &A::z;
+ clang_analyzer_eval(l); // expected-warning{{UNKNOWN}}
+ clang_analyzer_eval(m); // expected-warning{{UNKNOWN}}
+ clang_analyzer_eval(n); // expected-warning{{UNKNOWN}}
+
+ // FIXME: These should be true as well.
+ A a;
+ a.x = 1;
+ clang_analyzer_eval(a.*l == 1); // expected-warning{{UNKNOWN}}
+ a.y = 2;
+ clang_analyzer_eval(a.*m == 2); // expected-warning{{UNKNOWN}}
+ a.z = 3;
+ clang_analyzer_eval(a.*n == 3); // expected-warning{{UNKNOWN}}
+}
+} // end of testAnonymousMember namespace
Index: lib/StaticAnalyzer/Core/ExprEngine.cpp
===================================================================
--- lib/StaticAnalyzer/Core/ExprEngine.cpp
+++ lib/StaticAnalyzer/Core/ExprEngine.cpp
@@ -2108,7 +2108,7 @@
ProgramPoint::PostLValueKind);
return;
}
- if (isa<FieldDecl>(D)) {
+ if (isa<FieldDecl>(D) || isa<IndirectFieldDecl>(D)) {
// FIXME: Compute lvalue of field pointers-to-member.
// Right now we just use a non-null void pointer, so that it gives proper
// results in boolean contexts.
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