fix some gcc warnings, and maybe even a ppu bug?

first commit in a _long_ time, and it's just because I installed a
fresh linux distro and wanted to see if ANESE compiles on it.
It does, but I noticed a couple of warnings and bugs, so these are
some quick fixes.

looks like I had an unintended fallthrough in my bgr_fetch routine.
not sure how mission-critical this is, but maybe it fixes stuff?

other than that, g++ helpfuly noted some other silly errors and
unused vars, so I cleaned those up too.

lastly, I removed some code that skipped the first directory
returned by cute_files in the menu component. Not _super_ sure why
that was there in the first place, but directory traversal now
works on some more linux distros (such as the one I am running)

CMakeLists.txt

@@ -32,7 +32,7 @@ endif(NOT CMAKE_BUILD_TYPE)
 
 # Setup compiler flags for different platforms
 if (${CMAKE_CXX_COMPILER_ID} STREQUAL "GNU" OR ${CMAKE_CXX_COMPILER_ID} STREQUAL "Clang")
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra -pedantic -fno-exceptions -fno-rtti -std=c++11")
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra -pedantic -fno-exceptions -fno-rtti -Wno-class-memaccess -std=c++11")
   set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS} -g -fsanitize=undefined -fsanitize=address")
   set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS} -O3 -g")
 elseif (${CMAKE_CXX_COMPILER_ID} STREQUAL MSVC)

src/nes/cpu/cpu.cc

@@ -60,8 +60,10 @@ void CPU::service_interrupt(Interrupts::Type interrupt, bool brk /* = false */)
   this->cycles += 7;
 
   switch (interrupt) {
-  case Interrupts::IRQ: if (brk || !this->reg.p.i)
-                          this->reg.pc = this->read16(0xFFFE); break;
+  case Interrupts::IRQ:
+    if (brk || !this->reg.p.i)
+      this->reg.pc = this->read16(0xFFFE);
+    break;
   case Interrupts::RESET: this->reg.pc = this->read16(0xFFFC); break;
   case Interrupts::NMI:   this->reg.pc = this->read16(0xFFFA); break;
   default: break;
@@ -424,7 +426,7 @@ u16 CPU::peek16(u16 addr) const {
 u16 CPU::read16(u16 addr) {
   return this->mem.read(addr + 0) |
         (this->mem.read(addr + 1) << 8);
-};
+}
 
 u16 CPU::peek16_zpg(u16 addr) const {
   return this->mem.peek(addr + 0) |

src/nes/ppu/ppu.cc

@@ -442,7 +442,7 @@ void PPU::bgr_fetch() {
 
       this->bgr.shift.at_latch[0] = this->bgr.at_byte & 1;
       this->bgr.shift.at_latch[1] = this->bgr.at_byte & 2;
-    }
+    } break;
     // 1) Fetch Nametable Byte
     // https://wiki.nesdev.com/w/index.php/PPU_scrolling#Tile_and_attribute_fetching
     case 2: {

src/ui/SDL2/fs/util.cc

@@ -18,8 +18,9 @@ void get_abs_path(char* abs_path, const char* path, unsigned int n) {
 #ifdef WIN32
   GetFullPathName(path, n, abs_path, nullptr);
 #else
+  const char* _ = realpath(path, abs_path);
   (void)n;
-  (void)realpath(path, abs_path);
+  (void)_;
 #endif
 }
 

src/ui/SDL2/gui_modules/emu.cc

@@ -204,7 +204,7 @@ void EmuModule::input(const SDL_Event& event) {
     // Use CMD on macOS, and CTRL on windows / linux
     bool mod_ctrl = strcmp(SDL_GetPlatform(), "Mac OS X") == 0
       ? event.key.keysym.mod & (KMOD_LGUI | KMOD_RGUI)
-      : mod_ctrl = event.key.keysym.mod & (KMOD_LCTRL | KMOD_RCTRL);
+      : event.key.keysym.mod & (KMOD_LCTRL | KMOD_RCTRL);
 
     // Regular 'ol keys
     switch (event.key.keysym.sym) {

src/ui/SDL2/gui_modules/submodules/menu.cc

@@ -110,14 +110,11 @@ void MenuSubModule::update() {
     // Get file-listing
     cf_dir_t dir;
     cf_dir_open(&dir, this->nav.directory);
-    bool skip_first = true;
     while (dir.has_next) {
       cf_file_t file;
       cf_read_file(&dir, &file);
-      if (!skip_first)
-        files.push_back(file);
+      files.push_back(file);
       cf_dir_next(&dir);
-      skip_first = false;
     }
     cf_dir_close(&dir);
 

thirdparty/headeronly/stb_image.h

@@ -6338,6 +6338,7 @@ static stbi_uc *stbi__process_gif_raster(stbi__context *s, stbi__gif *g)
 // two back is the image from two frames ago, used for a very specific disposal format
 static stbi_uc *stbi__gif_load_next(stbi__context *s, stbi__gif *g, int *comp, int req_comp, stbi_uc *two_back)
 {
+   (void) req_comp;
    int dispose;
    int first_frame;
    int pi;
@@ -6562,6 +6563,7 @@ static void *stbi__load_gif_main(stbi__context *s, int **delays, int *x, int *y,
 
 static void *stbi__gif_load(stbi__context *s, int *x, int *y, int *comp, int req_comp, stbi__result_info *ri)
 {
+   (void)ri;
    stbi_uc *u = 0;
    stbi__gif g;
    memset(&g, 0, sizeof(g));