Fix misuse of OStringLiteral

...(which got introduced with 9b5dad13b56bdde7c40970351af3da3a2c3c9350
"loplugin:stringadd look for unnecessary temporaries", and had reportedly
broken CppunitTest_sc_ucalc on tml's Windows build by hitting the
"strlen( str ) == N - 1" assert at include/rtl/string.hxx:1867), by introducing
rtl::OStringView (and rtl::OUStringView, for consistency).

Change-Id: I766b600274302ded66a6bffc91be189b20ed1ac3
Reviewed-on: https://gerrit.libreoffice.org/80778
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

4 files changed, 62 insertions, 1 deletions

diff --git a/include/rtl/stringconcat.hxx b/include/rtl/stringconcat.hxx
index 3fd8b6720851..c075a29d9c80 100644
--- a/include/rtl/stringconcat.hxx
+++ b/include/rtl/stringconcat.hxx
@@ -480,6 +480,61 @@ struct ToStringHelper< OUStringNumber< T > >
     static const bool allowOUStringConcat = true;
     };
 
+// Abstractions over null-terminated char and sal_Unicode strings that sometimes are needed in
+// concatenations of multiple such raw strings, as in
+//
+//   char const * s1, s2;
+//   OString s = OStringView(s1) + s2;
+//
+// (Providing specializations of ToStringHelper<std::string_view> and
+// ToStringHelper<std::u16string_view> would look dubious, as it would give meaning to expressions
+// like
+//
+//   std::string_view(s1) + s2
+//
+// that do not involve any user-defined types.)
+
+class OStringView {
+public:
+    explicit OStringView(char const * s): view_(s) {}
+
+    std::size_t length() const { return view_.length(); }
+
+    char const * data() const { return view_.data(); }
+
+private:
+    std::string_view view_;
+};
+
+template<>
+struct ToStringHelper< OStringView >
+    {
+    static std::size_t length( const OStringView& v ) { return v.length(); }
+    static char* addData( char* buffer, const OStringView& v ) SAL_RETURNS_NONNULL { return addDataHelper( buffer, v.data(), v.length() ); }
+    static const bool allowOStringConcat = true;
+    static const bool allowOUStringConcat = false;
+    };
+
+class OUStringView {
+public:
+    explicit OUStringView(sal_Unicode const * s): view_(s) {}
+
+    std::size_t length() const { return view_.length(); }
+
+    sal_Unicode const * data() const { return view_.data(); }
+
+private:
+    std::u16string_view view_;
+};
+
+template<>
+struct ToStringHelper< OUStringView >
+    {
+    static std::size_t length( const OUStringView& v ) { return v.length(); }
+    static sal_Unicode* addData( sal_Unicode* buffer, const OUStringView& v ) SAL_RETURNS_NONNULL { return addDataHelper( buffer, v.data(), v.length() ); }
+    static const bool allowOStringConcat = false;
+    static const bool allowOUStringConcat = true;
+    };
 
 } // namespace
 
diff --git a/opencl/source/openclwrapper.cxx b/opencl/source/openclwrapper.cxx
index e1645ebe85ff..a1aa5e90950c 100644
--- a/opencl/source/openclwrapper.cxx
+++ b/opencl/source/openclwrapper.cxx
@@ -185,7 +185,7 @@ OString createFileName(cl_device_id deviceId, const char* clFileName)
             platformVersion, nullptr);
 
     // create hash for deviceName + driver version + platform version
-    OString aString = OStringLiteral(deviceName) + driverVersion + platformVersion;
+    OString aString = rtl::OStringView(deviceName) + driverVersion + platformVersion;
     OString aHash = generateMD5(aString.getStr(), aString.getLength());
 
     return getCacheFolder() + fileName + "-" + aHash + ".bin";
diff --git a/sal/qa/rtl/strings/test_ostring_concat.cxx b/sal/qa/rtl/strings/test_ostring_concat.cxx
index e676aab2d27e..fc310dbb58bd 100644
--- a/sal/qa/rtl/strings/test_ostring_concat.cxx
+++ b/sal/qa/rtl/strings/test_ostring_concat.cxx
@@ -83,6 +83,8 @@ void test::ostring::StringConcat::checkConcat()
     CPPUNIT_ASSERT_EQUAL(( typeid( OStringConcat< OString, char* > )), typeid( OString( "foo" ) + d4 ));
     CPPUNIT_ASSERT_EQUAL( OString( "fooabc" ), OString( OString( "foo" ) + d4 ));
     CPPUNIT_ASSERT_EQUAL(( typeid( OStringConcat< OString, char* > )), typeid( OString( "foo" ) + d4 ));
+    CPPUNIT_ASSERT_EQUAL( OString( "fooabc" ), OString( rtl::OStringView( "foo" ) + d4 ));
+    CPPUNIT_ASSERT_EQUAL(( typeid( OStringConcat< rtl::OStringView, char* > )), typeid( rtl::OStringView( "foo" ) + d4 ));
 
     CPPUNIT_ASSERT_EQUAL( OString( "num10" ), OString( OString( "num" ) + OString::number( 10 )));
     CPPUNIT_ASSERT_EQUAL(( typeid( OStringConcat< OString, OStringNumber< int > > )), typeid( OString( "num" ) + OString::number( 10 )));
@@ -157,6 +159,7 @@ void test::ostring::StringConcat::checkInvalid()
     CPPUNIT_ASSERT( INVALID_CONCAT( OString( "a" ) + OUString( "b" )));
     CPPUNIT_ASSERT( INVALID_CONCAT( OString( "a" ) + OUStringBuffer( "b" )));
     CPPUNIT_ASSERT( INVALID_CONCAT( OString( "a" ) + OUStringLiteral( "b" )));
+    CPPUNIT_ASSERT( INVALID_CONCAT( OString( "a" ) + rtl::OUStringView( u"b" )));
     CPPUNIT_ASSERT( INVALID_CONCAT( OString( "a" ) + 1 ));
     rtl_String* rs = nullptr;
     rtl_uString* rus = nullptr;
diff --git a/sal/qa/rtl/strings/test_oustring_concat.cxx b/sal/qa/rtl/strings/test_oustring_concat.cxx
index 6e1b209f7189..b67a2938ea36 100644
--- a/sal/qa/rtl/strings/test_oustring_concat.cxx
+++ b/sal/qa/rtl/strings/test_oustring_concat.cxx
@@ -74,6 +74,8 @@ void test::oustring::StringConcat::checkConcat()
     const sal_Unicode* d2 = u"xyz";
     CPPUNIT_ASSERT_EQUAL( OUString( "fooxyz" ), OUString( OUString( "foo" ) + d2 ));
     CPPUNIT_ASSERT_EQUAL(( typeid( OUStringConcat< OUString, const sal_Unicode* > )), typeid( OUString( "foo" ) + d2 ));
+    CPPUNIT_ASSERT_EQUAL( OUString( "fooxyz" ), OUString( rtl::OUStringView( u"foo" ) + d2 ));
+    CPPUNIT_ASSERT_EQUAL(( typeid( OUStringConcat< rtl::OUStringView, const sal_Unicode* > )), typeid( rtl::OUStringView( u"foo" ) + d2 ));
 
     CPPUNIT_ASSERT_EQUAL( OUString( "num10" ), OUString( OUString( "num" ) + OUString::number( 10 )));
     CPPUNIT_ASSERT_EQUAL(( typeid( OUStringConcat< OUString, OUStringNumber< int > > )), typeid( OUString( "num" ) + OUString::number( 10 )));
@@ -168,6 +170,7 @@ void test::oustring::StringConcat::checkInvalid()
     CPPUNIT_ASSERT( INVALID_CONCAT( OUString( "a" ) + d ));
     CPPUNIT_ASSERT( INVALID_CONCAT( OUString( "a" ) + static_cast<char*>(d) ));
     CPPUNIT_ASSERT( INVALID_CONCAT( OUString( "a" ) + OStringLiteral( "b" )));
+    CPPUNIT_ASSERT( INVALID_CONCAT( OUString( "a" ) + rtl::OStringView( "b" )));
     CPPUNIT_ASSERT( INVALID_CONCAT( OUString( "a" ) + 1 ));
     rtl_String* rs = nullptr;
     rtl_uString* rus = nullptr;