Silence several Vulkan related warnings that showed up in Xcode

gfx/common/vulkan_common.c

@@ -1549,7 +1549,6 @@ static bool vulkan_context_init_gpu(gfx_ctx_vulkan_data_t *vk)
 
 static bool vulkan_context_init_device(gfx_ctx_vulkan_data_t *vk)
 {
-   bool use_device_ext;
    uint32_t queue_count;
    unsigned i;
    static const float one                  = 1.0f;
@@ -1733,7 +1732,7 @@ static bool vulkan_context_init_device(gfx_ctx_vulkan_data_t *vk)
          return false;
       }
 
-      if (!(use_device_ext = vulkan_find_device_extensions(vk->context.gpu,
+      if (!(vulkan_find_device_extensions(vk->context.gpu,
               enabled_device_extensions, &enabled_device_extension_count,
               device_extensions, ARRAY_SIZE(device_extensions),
               optional_device_extensions,

gfx/drivers/vulkan.c

@@ -1857,8 +1857,6 @@ static void vulkan_set_viewport(void *data, unsigned viewport_width,
    bool video_scale_integer  = settings->bools.video_scale_integer;
    unsigned aspect_ratio_idx = settings->uints.video_aspect_ratio_idx;
    vk_t *vk                  = (vk_t*)data;
-   unsigned width            = vk->video_width;
-   unsigned height           = vk->video_height;
 
    if (vk->ctx_driver->translate_aspect)
       device_aspect         = vk->ctx_driver->translate_aspect(
@@ -3346,7 +3344,7 @@ static bool vulkan_read_viewport(void *data, uint8_t *buffer, bool is_idle)
                && (staging->memory != VK_NULL_HANDLE))
             VULKAN_SYNC_TEXTURE_TO_CPU(vk->context->device, staging->memory);
 
-         ctx->in_stride  = staging->stride;
+         ctx->in_stride  =  (int)staging->stride;
          ctx->out_stride = -(int)vk->vp.width * 3;
          scaler_ctx_scale_direct(ctx, buffer, src);
 

gfx/drivers_context/cocoa_vk_ctx.m

@@ -59,14 +59,13 @@ CocoaView *cocoaview_get(void);
 
 static uint32_t cocoa_vk_gfx_ctx_get_flags(void *data)
 {
-   uint32_t flags                 = 0;
-   cocoa_vk_ctx_data_t    *cocoa_ctx = (cocoa_vk_ctx_data_t*)data;
-
 #if defined(HAVE_SLANG) && defined(HAVE_SPIRV_CROSS)
+   uint32_t flags = 0;
    BIT32_SET(flags, GFX_CTX_FLAGS_SHADERS_SLANG);
-#endif
-
    return flags;
+#else
+   return 0;
+#endif
 }
 
 static void cocoa_vk_gfx_ctx_set_flags(void *data, uint32_t flags) { }

gfx/drivers_font/vulkan_raster_font.c

@@ -1,4 +1,4 @@
-/*  RetroArch - A frontend for libretro.
+/*  RetroArch - A frontend for libretro.
  *  Copyright (C) 2016-2017 - Hans-Kristian Arntzen
  *
  *  RetroArch is free software: you can redistribute it and/or modify it under the terms
@@ -357,7 +357,7 @@ static void vulkan_font_render_msg(
    float color[4];
    int drop_x, drop_y;
    bool full_screen;
-   unsigned max_glyphs;
+   size_t max_glyphs;
    unsigned width, height;
    enum text_alignment text_align;
    float x, y, scale, drop_mod, drop_alpha;

gfx/drivers_shader/shader_vulkan.cpp

@@ -1434,12 +1434,14 @@ bool vulkan_filter_chain::init_feedback()
 
 bool vulkan_filter_chain::init_alias()
 {
-   unsigned i, j;
+   int i;
+   
    common.texture_semantic_map.clear();
    common.texture_semantic_uniform_map.clear();
 
    for (i = 0; i < passes.size(); i++)
    {
+      unsigned j;
       const std::string name = passes[i]->get_name();
       if (name.empty())
          continue;
@@ -1469,7 +1471,7 @@ bool vulkan_filter_chain::init_alias()
 
    for (i = 0; i < common.luts.size(); i++)
    {
-      j = &common.luts[i] - common.luts.data();
+      unsigned j = &common.luts[i] - common.luts.data();
       if (!slang_set_unique_map(
                common.texture_semantic_map,
                common.luts[i]->get_id(),
@@ -1922,7 +1924,7 @@ bool Pass::init_pipeline_layout()
       }
    }
 
-   set_layout_info.bindingCount           = bindings.size();
+   set_layout_info.bindingCount           = (uint32_t)bindings.size();
    set_layout_info.pBindings              = bindings.data();
 
    if (vkCreateDescriptorSetLayout(device,
@@ -1950,14 +1952,14 @@ bool Pass::init_pipeline_layout()
    }
 
    push.stages     = push_range.stageFlags;
-   push_range.size = reflection.push_constant_size;
+   push_range.size = (uint32_t)reflection.push_constant_size;
 
    if (vkCreatePipelineLayout(device,
             &layout_info, NULL, &pipeline_layout) != VK_SUCCESS)
       return false;
 
    pool_info.maxSets                    = num_sync_indices;
-   pool_info.poolSizeCount              = desc_counts.size();
+   pool_info.poolSizeCount              = (uint32_t)desc_counts.size();
    pool_info.pPoolSizes                 = desc_counts.data();
    if (vkCreateDescriptorPool(device, &pool_info, nullptr, &pool) != VK_SUCCESS)
       return false;
@@ -2600,7 +2602,7 @@ void Pass::build_commands(
    if (push.stages != 0)
    {
       vkCmdPushConstants(cmd, pipeline_layout,
-            push.stages, 0, reflection.push_constant_size,
+            push.stages, 0, (uint32_t)reflection.push_constant_size,
             push.buffer.data());
    }
 
@@ -2965,7 +2967,7 @@ vulkan_filter_chain_t *vulkan_filter_chain_create_from_preset(
                      itr->id);
                goto error;
             }
-            chain->add_parameter(i, itr - shader->parameters, meta_param.id);
+            chain->add_parameter(i, (unsigned)(itr - shader->parameters), meta_param.id);
          }
          else
          {