[analyzer] Support C++ default arguments if they are literal values.
A CXXDefaultArgExpr wraps an Expr owned by a ParmVarDecl belonging to the
called function. In general, ExprEngine and Environment ought to treat this
like a ParenExpr or other transparent wrapper expression, with the inside
expression evaluated first.
However, if we call the same function twice, we'd produce a CFG that contains
the same wrapped expression twice, and we're not set up to handle that. I've
added a FIXME to the CFG builder to come back to that, but meanwhile we can
at least handle expressions that don't need to be explicitly evaluated:
literals. This probably handles many common uses of default parameters:
true/false, null, etc.
Part of PR13385 / <rdar://problem/12156507>
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@162453 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Analysis/inline.cpp b/test/Analysis/inline.cpp
index 6b9a885..6590776 100644
--- a/test/Analysis/inline.cpp
+++ b/test/Analysis/inline.cpp
@@ -193,3 +193,37 @@
}
};
}
+
+namespace DefaultArgs {
+ int takesDefaultArgs(int i = 42) {
+ return -i;
+ }
+
+ void testFunction() {
+ clang_analyzer_eval(takesDefaultArgs(1) == -1); // expected-warning{{TRUE}}
+ clang_analyzer_eval(takesDefaultArgs() == -42); // expected-warning{{TRUE}}
+ }
+
+ class Secret {
+ public:
+ static const int value = 42;
+ int get(int i = value) {
+ return i;
+ }
+ };
+
+ void testMethod() {
+ Secret obj;
+ clang_analyzer_eval(obj.get(1) == 1); // expected-warning{{TRUE}}
+
+ // FIXME: Should be 'TRUE'. See PR13673 or <rdar://problem/11720796>.
+ clang_analyzer_eval(obj.get() == 42); // expected-warning{{UNKNOWN}}
+
+ // FIXME: Even if we constrain the variable, we still have a problem.
+ // See PR13385 or <rdar://problem/12156507>.
+ if (Secret::value != 42)
+ return;
+ clang_analyzer_eval(Secret::value == 42); // expected-warning{{TRUE}}
+ clang_analyzer_eval(obj.get() == 42); // expected-warning{{UNKNOWN}}
+ }
+}