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>

3 files changed, 7 insertions, 5 deletions

diff --git a/extensions/source/bibliography/bibload.cxx b/extensions/source/bibliography/bibload.cxx
index b9aa15092714..e0bf5b4a2c71 100644
--- a/extensions/source/bibliography/bibload.cxx
+++ b/extensions/source/bibliography/bibload.cxx
@@ -74,6 +74,8 @@ using namespace ::com::sun::star::form;
 using namespace ::com::sun::star::container;
 using namespace ::com::sun::star::frame;
 
+static Reference< XInterface > BibliographyLoader_CreateInstance( const Reference< XMultiServiceFactory > & rSMgr );
+
 class BibliographyLoader : public cppu::WeakImplHelper
                             < XServiceInfo, XNameAccess, XPropertySet, XFrameLoader >
 {
diff --git a/extensions/source/bibliography/datman.cxx b/extensions/source/bibliography/datman.cxx
index 02333733f83d..846cd1ceebbd 100644
--- a/extensions/source/bibliography/datman.cxx
+++ b/extensions/source/bibliography/datman.cxx
@@ -83,7 +83,7 @@ using namespace ::com::sun::star::form;
 using namespace ::com::sun::star::frame;
 using namespace ::com::sun::star::lang;
 
-Reference< XConnection > getConnection(const OUString& _rURL)
+static Reference< XConnection > getConnection(const OUString& _rURL)
 {
     // first get the sdb::DataSource corresponding to the url
     Reference< XDataSource >    xDataSource;
@@ -124,7 +124,7 @@ Reference< XConnection > getConnection(const OUString& _rURL)
     return xConn;
 }
 
-Reference< XConnection >    getConnection(const Reference< XInterface > & xRowSet)
+static Reference< XConnection >    getConnection(const Reference< XInterface > & xRowSet)
 {
     Reference< XConnection >    xConn;
     try
@@ -147,7 +147,7 @@ Reference< XConnection >    getConnection(const Reference< XInterface > & xRowSe
     return xConn;
 }
 
-Reference< XNameAccess >  getColumns(const Reference< XForm > & _rxForm)
+static Reference< XNameAccess >  getColumns(const Reference< XForm > & _rxForm)
 {
     Reference< XNameAccess >  xReturn;
     // check if the form is alive
diff --git a/extensions/source/bibliography/framectr.cxx b/extensions/source/bibliography/framectr.cxx
index 7f6e188c14bc..b6bd50f6e67b 100644
--- a/extensions/source/bibliography/framectr.cxx
+++ b/extensions/source/bibliography/framectr.cxx
@@ -100,7 +100,7 @@ static const DispatchInfo SupportedCommandsArray[] =
 
 typedef std::unordered_map< OUString, CacheDispatchInfo > CmdToInfoCache;
 
-const CmdToInfoCache& GetCommandToInfoCache()
+static const CmdToInfoCache& GetCommandToInfoCache()
 {
     static bool       bCacheInitialized = false;
     static CmdToInfoCache aCmdToInfoCache;
@@ -318,7 +318,7 @@ uno::Sequence< frame::DispatchInformation > SAL_CALL BibFrameController_Impl::ge
     return comphelper::containerToSequence( aDispatchInfoVector );
 }
 
-bool canInsertRecords(const Reference< beans::XPropertySet>& _rxCursorSet)
+static bool canInsertRecords(const Reference< beans::XPropertySet>& _rxCursorSet)
 {
     sal_Int32 nPriv = 0;
     _rxCursorSet->getPropertyValue("Privileges") >>= nPriv;