New loplugin:external

...warning about (for now only) functions and variables with external linkage
that likely don't need it.

The problems with moving entities into unnamed namespacs and breaking ADL
(as alluded to in comments in compilerplugins/clang/external.cxx) are
illustrated by the fact that while

struct S1 { int f() { return 0; } };
int f(S1 s) { return s.f(); }
namespace N {
struct S2: S1 { int f() { return 1; } };
int f(S2 s) { return s.f(); }
}
int main() { return f(N::S2()); }

returns 1, both moving just the struct S2 into an nunnamed namespace,

struct S1 { int f() { return 0; } };
int f(S1 s) { return s.f(); }
namespace N {
namespace { struct S2: S1 { int f() { return 1; } }; }
int f(S2 s) { return s.f(); }
}
int main() { return f(N::S2()); }

as well as moving just the function f overload into an unnamed namespace,

struct S1 { int f() { return 0; } };
int f(S1 s) { return s.f(); }
namespace N {
struct S2: S1 { int f() { return 1; } };
namespace { int f(S2 s) { return s.f(); } }
}
int main() { return f(N::S2()); }

would each change the program to return 0 instead.

Change-Id: I4d09f7ac5e8f9bcd6e6bde4712608444b642265c
Reviewed-on: https://gerrit.libreoffice.org/60539
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/filter/source/svg/svgexport.cxx b/filter/source/svg/svgexport.cxx
index fa0958decc10..ac9550d7c6ca 100644
--- a/filter/source/svg/svgexport.cxx
+++ b/filter/source/svg/svgexport.cxx
@@ -302,7 +302,7 @@ public:
 };
 
 
-bool operator==( const TextField & aLhsTextField, const TextField & aRhsTextField )
+static bool operator==( const TextField & aLhsTextField, const TextField & aRhsTextField )
 {
     return aLhsTextField.equalTo( aRhsTextField );
 }
@@ -439,7 +439,7 @@ BitmapChecksum GetBitmapChecksum( const MetaAction* pAction )
 } // end anonymous namespace
 
 
-void MetaBitmapActionGetPoint( const MetaAction* pAction, Point& rPt )
+static void MetaBitmapActionGetPoint( const MetaAction* pAction, Point& rPt )
 {
     const MetaActionType nType = pAction->GetType();
     switch( nType )
@@ -878,7 +878,7 @@ bool SVGFilter::implExportDocument()
 
 /// Append aField to aFieldSet if it is not already present in the set and create the field id sFieldId
 template< typename TextFieldType >
-OUString implGenerateFieldId( std::vector< TextField* > & aFieldSet,
+static OUString implGenerateFieldId( std::vector< TextField* > & aFieldSet,
                               const TextFieldType & aField,
                               const OUString & sOOOElemField,
                               const Reference< css::drawing::XDrawPage >& xMasterPage )