path: Add getPathFromFilename (returns the path part of a filename)

E.g.,

  /tmp/a.h -> /tmp/
  a.h ->

etc.

lib/path.cpp

@@ -104,6 +104,19 @@ std::string Path::simplifyPath(const char *originalPath)
     return oss.str();
 }
 
+std::string Path::getPathFromFilename(const std::string &filename)
+{
+    std::string path = "";
+
+    std::size_t pos = filename.find_last_of("\\/");
+
+    if (pos != std::string::npos)
+        path = filename.substr(0, 1 + pos);
+
+    return path;
+}
+
+
 bool Path::sameFileName(const std::string &fname1, const std::string &fname2)
 {
 #if defined(__linux__) || defined(__sun) || defined(__hpux)

lib/path.h

@@ -56,6 +56,13 @@ public:
      */
     static std::string simplifyPath(const char *originalPath);
 
+    /**
+     * @brief Lookup the path part from a filename (e.g., '/tmp/a.h' -> '/tmp/', 'a.h' -> '')
+     * @param filename filename to lookup, must have / -separators.
+     * @return path part of the filename
+     */
+    static std::string getPathFromFilename(const std::string &filename);
+
     /**
      * @brief Compare filenames to see if they are the same.
      * On Linux the comparison is case-sensitive. On Windows it is case-insensitive.

lib/preprocessor.cpp

@@ -815,15 +815,8 @@ void Preprocessor::preprocess(std::istream &srcCodeStream, std::string &processe
             fin.open(cur.c_str());
             if (!fin.is_open()) {
                 if (_settings && !_settings->nomsg.isSuppressed("missingInclude", cur, 1)) {
-                    std::string path = "";
-
-                    std::size_t pos = cur.find_last_of("\\/");
-
-                    if (pos != std::string::npos)
-                        path = cur.substr(0, 1 + pos);
-
                     missingIncludeFlag = true;
-                    missingInclude(Path::toNativeSeparators(path),
+                    missingInclude(Path::toNativeSeparators(Path::getPathFromFilename(cur)),
                                    1,
                                    cur,
                                    true);

test/testpath.cpp

@@ -33,6 +33,7 @@ private:
         TEST_CASE(getRelative);
         TEST_CASE(is_c);
         TEST_CASE(is_cpp);
+        TEST_CASE(get_path_from_filename);
     }
 
     void simplify_path() const {
@@ -117,6 +118,13 @@ private:
         ASSERT(Path::isCPP("C:\\foo\\index.cpp"));
         ASSERT(Path::isCPP("C:\\foo\\index.Cpp"));
     }
+
+    void get_path_from_filename() const {
+        ASSERT_EQUALS("", Path::getPathFromFilename("index.h"));
+        ASSERT_EQUALS("/tmp/", Path::getPathFromFilename("/tmp/index.h"));
+        ASSERT_EQUALS("a/b/c/", Path::getPathFromFilename("a/b/c/index.h"));
+        ASSERT_EQUALS("a/b/c/", Path::getPathFromFilename("a/b/c/"));
+    }
 };
 
 REGISTER_TEST(TestPath)