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, 5 insertions, 5 deletions

diff --git a/unoidl/source/sourceprovider-parser.y b/unoidl/source/sourceprovider-parser.y
index bb4f5dc2a92a..747437660fdc 100644
--- a/unoidl/source/sourceprovider-parser.y
+++ b/unoidl/source/sourceprovider-parser.y
@@ -63,7 +63,7 @@
 #define YYLLOC_DEFAULT(Current, Rhs, N) \
     do { (Current) = YYRHSLOC((Rhs), (N) ? 1 : 0); } while (0)
 
-void yyerror(YYLTYPE * locp, yyscan_t yyscanner, char const * msg) {
+static void yyerror(YYLTYPE * locp, yyscan_t yyscanner, char const * msg) {
     assert(locp != nullptr);
     unoidl::detail::SourceProviderScannerData * data = yyget_extra(yyscanner);
     data->errorLine = *locp;
diff --git a/unoidl/source/unoidl-check.cxx b/unoidl/source/unoidl-check.cxx
index 41ad76143cd1..94f335cd1266 100644
--- a/unoidl/source/unoidl-check.cxx
+++ b/unoidl/source/unoidl-check.cxx
@@ -27,7 +27,7 @@
 
 namespace unoidl {
 
-bool operator ==(ConstantValue const & lhs, ConstantValue const & rhs) {
+static bool operator ==(ConstantValue const & lhs, ConstantValue const & rhs) {
     if (lhs.type == rhs.type) {
         switch (lhs.type) {
         case ConstantValue::TYPE_BOOLEAN:
@@ -55,11 +55,11 @@ bool operator ==(ConstantValue const & lhs, ConstantValue const & rhs) {
     return false;
 }
 
-bool operator !=(ConstantValue const & lhs, ConstantValue const & rhs) {
+static bool operator !=(ConstantValue const & lhs, ConstantValue const & rhs) {
     return !(lhs == rhs);
 }
 
-bool operator ==(
+static bool operator ==(
     SingleInterfaceBasedServiceEntity::Constructor::Parameter const & lhs,
     SingleInterfaceBasedServiceEntity::Constructor::Parameter const & rhs)
 {
diff --git a/unoidl/source/unoidlprovider.cxx b/unoidl/source/unoidlprovider.cxx
index cb3bd57074ea..bfbed9d02dd6 100644
--- a/unoidl/source/unoidlprovider.cxx
+++ b/unoidl/source/unoidlprovider.cxx
@@ -456,7 +456,7 @@ struct MapEntry {
     Memory32 data;
 };
 
-bool operator <(const Map& map1, const Map& map2) {
+static bool operator <(const Map& map1, const Map& map2) {
     return map1.begin < map2.begin
         || (map1.begin == map2.begin && map1.size < map2.size);
 }