loplugin:unnecessarygetstr fix false +

spotted in https://gerrit.libreoffice.org/c/core/+/162869

Change-Id: I87d9fdcfed5282f0e94fc8aa95a46054883fdd79
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/162929
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

2 files changed, 22 insertions, 3 deletions

diff --git a/compilerplugins/clang/test/unnecessarygetstr.cxx b/compilerplugins/clang/test/unnecessarygetstr.cxx
index c0960557a89b..bdb58cde2ef7 100644
--- a/compilerplugins/clang/test/unnecessarygetstr.cxx
+++ b/compilerplugins/clang/test/unnecessarygetstr.cxx
@@ -10,6 +10,7 @@
 #include <sal/config.h>
 
 #include <ostream>
+#include <sstream>
 #include <string_view>
 #include <string>
 
@@ -128,4 +129,10 @@ void foo(const OString&);
 void test(std::string v) { foo(v.c_str()); }
 }
 
+// no warning expected
+namespace test7
+{
+void test(const OString& v) { std::stringstream aStream(v.getStr()); }
+}
+
 /* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */
diff --git a/compilerplugins/clang/unnecessarygetstr.cxx b/compilerplugins/clang/unnecessarygetstr.cxx
index c80877a78554..589ab405f786 100644
--- a/compilerplugins/clang/unnecessarygetstr.cxx
+++ b/compilerplugins/clang/unnecessarygetstr.cxx
@@ -11,6 +11,7 @@
 
 #include <cassert>
 #include <stack>
+#include <unordered_set>
 
 #include "check.hxx"
 #include "plugin.hxx"
@@ -60,11 +61,20 @@ public:
         if (ignoreLocation(constructExpr))
             return true;
         auto tc = loplugin::TypeCheck(constructExpr->getType());
-        if (tc.ClassOrStruct("basic_string").StdNamespace())
+        if (tc.ClassOrStruct("basic_stringstream").StdNamespace())
+        {
+            // ignore the implicit-conversion nodes that are added here
+            if (constructExpr->getNumArgs() > 0)
+                nodesToIgnore.insert(constructExpr->getArg(0)->IgnoreImplicit());
+        }
+        else if (tc.ClassOrStruct("basic_string").StdNamespace())
         {
             if (constructExpr->getNumArgs() == 1 || constructExpr->getNumArgs() == 2)
-                checkForGetStr(constructExpr->getArg(0), "string constructor",
-                               /*isOStringConstructor*/ false);
+            {
+                if (nodesToIgnore.find(constructExpr) == nodesToIgnore.end())
+                    checkForGetStr(constructExpr->getArg(0), "string constructor",
+                                   /*isOStringConstructor*/ false);
+            }
         }
         else if (tc.ClassOrStruct("basic_string_view").StdNamespace())
         {
@@ -138,6 +148,8 @@ private:
             TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
         }
     }
+
+    std::unordered_set<const Expr*> nodesToIgnore;
 };
 
 loplugin::Plugin::Registration<UnnecessaryGetStr> unnecessarygetstr("unnecessarygetstr");