loplugin:unnecessarygetstr extend to checking std::string::c_str

Change-Id: I17398e2a6a31a2c98ba8e54b5c8045f22aee8759
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/150749
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

2 files changed, 45 insertions, 12 deletions

diff --git a/compilerplugins/clang/test/unnecessarygetstr.cxx b/compilerplugins/clang/test/unnecessarygetstr.cxx
index d04d2ca28402..12905ec5d233 100644
--- a/compilerplugins/clang/test/unnecessarygetstr.cxx
+++ b/compilerplugins/clang/test/unnecessarygetstr.cxx
@@ -18,6 +18,8 @@
 #include <rtl/ustring.hxx>
 #include <sal/log.hxx>
 
+namespace test1
+{
 void f1(bool, const OString& s);
 struct Foo
 {
@@ -41,7 +43,10 @@ void test1(Foo& foo)
         = "xx" + OUString(aVal.getStr(), aVal.getLength(), RTL_TEXTENCODING_ASCII_US);
     (void)aCompText;
 }
+}
 
+namespace test2
+{
 // call to param that takes string_view
 void f2(bool, std::string_view);
 struct Foo2
@@ -60,4 +65,24 @@ void test2(Foo2& foo)
     // expected-error@+1 {{unnecessary call to 'getStr' when passing to string_view arg [loplugin:unnecessarygetstr]}}
     foo.f2(true, OString::number(12).getStr());
 }
+}
+
+namespace test3
+{
+// call to param that takes string_view
+void f2(bool, std::string_view);
+struct Foo2
+{
+    void f2(bool, std::string_view);
+};
+void test3(Foo2& foo)
+{
+    std::string s;
+    // expected-error@+1 {{unnecessary call to 'c_str' when passing to string_view arg [loplugin:unnecessarygetstr]}}
+    f2(true, s.c_str());
+    // expected-error@+1 {{unnecessary call to 'c_str' when passing to string_view arg [loplugin:unnecessarygetstr]}}
+    foo.f2(true, s.c_str());
+}
+}
+
 /* 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 c72c9ae7598d..66f2fa2851fe 100644
--- a/compilerplugins/clang/unnecessarygetstr.cxx
+++ b/compilerplugins/clang/unnecessarygetstr.cxx
@@ -87,18 +87,26 @@ public:
                     continue;
                 auto const t = e->getObjectType();
                 auto const tc2 = loplugin::TypeCheck(t);
-                if (!(tc2.Class("OString").Namespace("rtl").GlobalNamespace()
-                      || tc2.Class("OUString").Namespace("rtl").GlobalNamespace()
-                      || tc2.Class("OStringBuffer").Namespace("rtl").GlobalNamespace()
-                      || tc2.Class("OUStringBuffer").Namespace("rtl").GlobalNamespace()
-                      || tc2.ClassOrStruct("StringNumber").Namespace("rtl").GlobalNamespace()))
-                    continue;
-                if (!loplugin::DeclCheck(e->getMethodDecl()).Function("getStr"))
-                    continue;
-                report(DiagnosticsEngine::Warning,
-                       "unnecessary call to 'getStr' when passing to string_view arg",
-                       e->getExprLoc())
-                    << e->getSourceRange();
+                if (tc2.Class("OString").Namespace("rtl").GlobalNamespace()
+                    || tc2.Class("OUString").Namespace("rtl").GlobalNamespace()
+                    || tc2.Class("OStringBuffer").Namespace("rtl").GlobalNamespace()
+                    || tc2.Class("OUStringBuffer").Namespace("rtl").GlobalNamespace()
+                    || tc2.ClassOrStruct("StringNumber").Namespace("rtl").GlobalNamespace())
+                {
+                    if (loplugin::DeclCheck(e->getMethodDecl()).Function("getStr"))
+                        report(DiagnosticsEngine::Warning,
+                               "unnecessary call to 'getStr' when passing to string_view arg",
+                               e->getExprLoc())
+                            << e->getSourceRange();
+                }
+                else if (tc2.Class("basic_string").StdNamespace())
+                {
+                    if (loplugin::DeclCheck(e->getMethodDecl()).Function("c_str"))
+                        report(DiagnosticsEngine::Warning,
+                               "unnecessary call to 'c_str' when passing to string_view arg",
+                               e->getExprLoc())
+                            << e->getSourceRange();
+                }
             }
         }
         return true;