Some refactoring and fixes based on static source code analysis

src/libslic3r/Arrange.cpp

@@ -552,7 +552,7 @@ static CircleBed to_circle(const Point &center, const Points& points) {
     std::vector<double> vertex_distances;
     double avg_dist = 0;
     
-    for (auto pt : points)
+    for (const Point& pt : points)
     {
         double distance = distance_to(center, pt);
         vertex_distances.push_back(distance);

src/libslic3r/Config.cpp

@@ -306,7 +306,7 @@ ConfigOptionDef* ConfigDef::add_nullable(const t_config_option_key &opt_key, Con
 std::ostream& ConfigDef::print_cli_help(std::ostream& out, bool show_defaults, std::function<bool(const ConfigOptionDef &)> filter) const
 {
     // prepare a function for wrapping text
-    auto wrap = [](std::string text, size_t line_length) -> std::string {
+    auto wrap = [](const std::string& text, size_t line_length) -> std::string {
         std::istringstream words(text);
         std::ostringstream wrapped;
         std::string word;
@@ -335,7 +335,7 @@ std::ostream& ConfigDef::print_cli_help(std::ostream& out, bool show_defaults, s
             categories.insert(def.category);
     }
     
-    for (auto category : categories) {
+    for (const std::string& category : categories) {
         if (category != "") {
             out << category << ":" << std::endl;
         } else if (categories.size() > 1) {

src/libslic3r/CustomGCode.cpp

@@ -41,7 +41,7 @@ extern void check_mode_for_custom_gcode_per_print_z(Info& info)
         return;
 
     bool is_single_extruder = true;
-    for (auto item : info.gcodes) 
+    for (const Item& item : info.gcodes)
     {
         if (item.type == ToolChange) {
             info.mode = MultiAsSingle;

src/libslic3r/Fill/FillBase.hpp

@@ -125,7 +125,7 @@ protected:
         unsigned int                      /* thickness_layers */,
         const std::pair<float, Point>   & /* direction */, 
         ExPolygon                         /* expolygon */,
-        Polylines                       & /* polylines_out */) {};
+        Polylines                       & /* polylines_out */) {}
 
     virtual float _layer_angle(size_t idx) const { return (idx & 1) ? float(M_PI/2.) : 0; }
 

src/libslic3r/Layer.hpp

@@ -18,7 +18,7 @@ class PrintObject;
 
 namespace FillAdaptive {
     struct Octree;
-};
+}
 
 namespace FillLightning {
     class Generator;

src/libslic3r/Model.cpp

@@ -903,7 +903,7 @@ indexed_triangle_set ModelObject::raw_indexed_triangle_set() const
             size_t j = out.indices.size();
             append(out.vertices, v->mesh().its.vertices);
             append(out.indices,  v->mesh().its.indices);
-            auto m = v->get_matrix();
+            const Transform3d& m = v->get_matrix();
             for (; i < out.vertices.size(); ++ i)
                 out.vertices[i] = (m * out.vertices[i].cast<double>()).cast<float>().eval();
             if (v->is_left_handed()) {

src/libslic3r/Preset.cpp

@@ -1498,7 +1498,7 @@ void PhysicalPrinter::update_preset_names_in_config()
     if (!preset_names.empty()) {
         std::vector<std::string>& values = config.option<ConfigOptionStrings>("preset_names")->values;
         values.clear();
-        for (auto preset : preset_names)
+        for (const std::string& preset : preset_names)
             values.push_back(preset);
 
         // temporary workaround for compatibility with older Slicer
@@ -1571,7 +1571,7 @@ void PhysicalPrinter::set_name(const std::string& name)
     this->name = name;
 }
 
-std::string PhysicalPrinter::get_full_name(std::string preset_name) const
+std::string PhysicalPrinter::get_full_name(const std::string& preset_name) const
 {
     return name + separator() + preset_name;
 }
@@ -1888,7 +1888,7 @@ std::vector<std::string> PhysicalPrinterCollection::get_printers_with_only_prese
 {
     std::vector<std::string> printers;
 
-    for (auto printer : m_printers)
+    for (const PhysicalPrinter& printer : m_printers)
         if (printer.preset_names.size() == 1 && *printer.preset_names.begin() == preset_name)
             printers.emplace_back(printer.name);
 

src/libslic3r/Preset.hpp

@@ -675,7 +675,7 @@ public:
     bool                operator<(const PhysicalPrinter& other) const { return this->name < other.name; }
 
     // get full printer name included a name of the preset
-    std::string         get_full_name(std::string preset_name) const;
+    std::string         get_full_name(const std::string &preset_name) const;
 
     // get printer name from the full name uncluded preset name
     static std::string  get_short_name(std::string full_name);

src/libslic3r/PresetBundle.cpp

@@ -267,7 +267,7 @@ PresetsConfigSubstitutions PresetBundle::load_presets(AppConfig &config, Forward
     std::string errors_cummulative;
     std::tie(substitutions, errors_cummulative) = this->load_system_presets(substitution_rule);
 
-    const std::string dir_user_presets = data_dir()
+    const std::string& dir_user_presets = data_dir()
 #ifdef SLIC3R_PROFILE_USE_PRESETS_SUBDIR
         // Store the print/filament/printer presets into a "presets" directory.
         + "/presets"

src/libslic3r/utils.cpp

@@ -962,8 +962,10 @@ std::string string_printf(const char *format, ...)
         ::vsnprintf(buffer.data(), buffer.size(), format, args2);
     }
 
-    buffer.resize(bufflen);
+    va_end(args1);
+    va_end(args2);
     
+    buffer.resize(bufflen);
     return buffer;
 }