do not analyse system headers in the compiler plugin

Change-Id: Ica1e233b45cc778bfdc86cfd608ada7fc261c6c2

compilerplugins/clang/bodynotinblock.cxx

@@ -32,8 +32,7 @@ void BodyNotInBlock::run()
 
 bool BodyNotInBlock::VisitFunctionDecl( FunctionDecl* declaration )
     {
-    // TODO also LO header files? or a subdir?
-    if( !context.getSourceManager().isFromMainFile( declaration->getLocStart()))
+    if( ignoreLocation( declaration ))
         return true;
     if( !declaration->doesThisDeclarationHaveABody())
         return true;

compilerplugins/clang/compileplugin.cxx

@@ -43,6 +43,11 @@ DiagnosticBuilder Plugin::report( DiagnosticsEngine::Level level, StringRef mess
     return diag.Report( loc, diag.getCustomDiagID( level, message ));
     }
 
+bool Plugin::ignoreLocation( SourceLocation loc )
+    {
+    return context.getSourceManager().isInSystemHeader( context.getSourceManager().getExpansionLoc( loc ));
+    }
+
 /**
  Class that manages all LO modules.
 */

compilerplugins/clang/compileplugin.hxx

@@ -24,9 +24,24 @@ class Plugin
         explicit Plugin( ASTContext& context );
     protected:
         DiagnosticBuilder report( DiagnosticsEngine::Level level, StringRef message, SourceLocation loc );
+        bool ignoreLocation( SourceLocation loc );
+        bool ignoreLocation( const Decl* decl );
+        bool ignoreLocation( const Stmt* stmt );
         ASTContext& context;
     };
 
+inline
+bool Plugin::ignoreLocation( const Decl* decl )
+    {
+    return ignoreLocation( decl->getLocStart());
+    }
+
+inline
+bool Plugin::ignoreLocation( const Stmt* stmt )
+    {
+    return ignoreLocation( stmt->getLocStart());
+    }
+
 } // namespace
 
 #endif // COMPILEPLUGIN_H

compilerplugins/clang/unusedvariablecheck.cxx

@@ -40,8 +40,7 @@ void UnusedVariableCheck::run()
 
 bool UnusedVariableCheck::VisitNamedDecl( NamedDecl* declaration )
     {
-    // TODO also LO header files? or a subdir?
-    if( !context.getSourceManager().isFromMainFile( declaration->getLocStart()))
+    if( ignoreLocation( declaration ))
         return true;
     if( !isa< VarDecl >( declaration ))
         return true;