enhance pass-by-ref plugin to detect large arguments

Detect arguments larger than 64 chars passed by value.

Change-Id: I9b0ea9ccb99d115984a26eab67c9cf6afd5f6cae
Signed-off-by: Stephan Bergmann <sbergman@redhat.com>

1 files changed, 20 insertions, 14 deletions

diff --git a/compilerplugins/clang/passstuffbyref.cxx b/compilerplugins/clang/passstuffbyref.cxx
index c4951e82ca7c..7ad891728238 100644
--- a/compilerplugins/clang/passstuffbyref.cxx
+++ b/compilerplugins/clang/passstuffbyref.cxx
@@ -8,6 +8,7 @@
  */
 
 #include <string>
+#include <set>
 
 #include "plugin.hxx"
 
@@ -46,27 +47,32 @@ bool PassStuffByRef::VisitFunctionDecl(const FunctionDecl * functionDecl) {
             continue;
         }
         string typeName = t1.getUnqualifiedType().getCanonicalType().getAsString();
-        if (typeName == "class rtl::OUString") {
-            report(
-                DiagnosticsEngine::Warning,
-                "passing OUString by value, rather pass by reference .e.g. 'const OUString&'",
-                pvDecl->getSourceRange().getBegin())
-              << pvDecl->getSourceRange();
+
+        bool bFound = false;
+        if (typeName == "class rtl::OUString" ||
+            typeName == "class rtl::OString" ||
+            typeName.find("class com::sun::star::uno::Sequence") == 0) {
+            bFound = true;
         }
-        else if (typeName == "class rtl::OString") {
-            report(
-                DiagnosticsEngine::Warning,
-                "passing OString by value, rather pass by reference .e.g. 'const OString&'",
-                pvDecl->getSourceRange().getBegin())
-              << pvDecl->getSourceRange();
+
+        if (!bFound && !t1->isIncompleteType()) {
+            const clang::Type* type = t1.getTypePtrOrNull();
+            if (type != nullptr) {
+                clang::CharUnits size =  compiler.getASTContext().getTypeSizeInChars(type);
+                if (size.getQuantity() > 64) {
+                    bFound = true;
+                }
+            }
         }
-        else if (typeName.find("class com::sun::star::uno::Sequence") == 0) {
+
+        if (bFound) {
             report(
                 DiagnosticsEngine::Warning,
-                "passing css::uno::Sequence by value, rather pass by reference .e.g. 'const css::uno::Sequence&' " + typeName,
+                "passing " + typeName + " by value, rather pass by reference .e.g. 'const " + typeName + "&'",
                 pvDecl->getSourceRange().getBegin())
               << pvDecl->getSourceRange();
         }
+
     }
     return true;
 }