unusedfields loplugin writeonly analysis improvements

(1) ignore reads inside copy/move constructors/operator=
(2) fix false+ when assigning to array field
(3) ignore reference ("&") fields

Change-Id: I69a1a1c567a0b28a783e605982e5150811b6cc4a

1 files changed, 20 insertions, 8 deletions

diff --git a/compilerplugins/clang/test/unusedfields.cxx b/compilerplugins/clang/test/unusedfields.cxx
index 1d43c81ea177..a66b7a6e7eca 100644
--- a/compilerplugins/clang/test/unusedfields.cxx
+++ b/compilerplugins/clang/test/unusedfields.cxx
@@ -17,29 +17,39 @@ struct Foo
 
 struct Bar
 // expected-error@-1 {{read m_bar2 [loplugin:unusedfields]}}
-// expected-error@-2 {{read m_bar3 [loplugin:unusedfields]}}
-// expected-error@-3 {{read m_bar4 [loplugin:unusedfields]}}
-// expected-error@-4 {{read m_bar5 [loplugin:unusedfields]}}
-// expected-error@-5 {{read m_bar6 [loplugin:unusedfields]}}
-// expected-error@-6 {{read m_barfunctionpointer [loplugin:unusedfields]}}
+// expected-error@-2 {{read m_bar4 [loplugin:unusedfields]}}
+// expected-error@-3 {{read m_bar5 [loplugin:unusedfields]}}
+// expected-error@-4 {{read m_bar6 [loplugin:unusedfields]}}
+// expected-error@-5 {{read m_barfunctionpointer [loplugin:unusedfields]}}
 {
     int  m_bar1;
     int  m_bar2 = 1;
     int* m_bar3;
+    int* m_bar3b;
     int  m_bar4;
     void (*m_barfunctionpointer)(int&);
     int  m_bar5;
     std::vector<int> m_bar6;
+    int m_bar7[5];
 
-    //check that we see reads of fields when referred to via constructor initializer
+    // check that we see reads of fields like m_foo1 when referred to via constructor initializer
     Bar(Foo const & foo) : m_bar1(foo.m_foo1) {}
 
+    // check that we don't see reads when inside copy/move constructor
+    Bar(Bar const & other) { m_bar3 = other.m_bar3; }
+
+    // check that we don't see reads when inside copy/move assignment operator
+    Bar& operator=(Bar const & other) { m_bar3 = other.m_bar3; return *this; }
+
     // check that we DONT see reads here
     int bar2() { return m_bar2; }
 
     // check that we DONT see reads here
-    void bar3()  { *m_bar3 = 2; }
-    void bar3b() { m_bar3 = nullptr; }
+    void bar3()
+    {
+        m_bar3 = nullptr;
+        m_bar3b = m_bar3 = nullptr;
+    }
 
     // check that we see reads of field when passed to a function pointer
     // check that we see read of a field that is a function pointer
@@ -50,6 +60,8 @@ struct Bar
 
     // check that we see reads of a field when used in ranged-for
     void bar6() { for (auto i : m_bar6) { (void)i; } }
+
+    void bar7() { m_bar7[3] = 1; }
 };
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */