Sanitizer fixes (#2280)

platform/default/src/mbgl/mtl/headless_backend.cpp

@@ -4,10 +4,11 @@
 #include <mbgl/mtl/context.hpp>
 #include <mbgl/gfx/backend_scope.hpp>
 
+#include <Metal/Metal.hpp>
+
 #include <cassert>
 #include <stdexcept>
 #include <type_traits>
-#include <Metal/Metal.hpp>
 
 namespace mbgl {
 namespace mtl {

platform/glfw/metal_backend.mm

@@ -1,11 +1,15 @@
 #include "metal_backend.h"
 
+#include <mbgl/mtl/mtl_fwd.hpp>
 #include <mbgl/mtl/renderable_resource.hpp>
+
 #include <Metal/Metal.hpp>
 #include <QuartzCore/CAMetalLayer.hpp>
 
 namespace mbgl {
 
+using namespace mtl;
+
 class MetalRenderableResource final: public mtl::RenderableResource {
 public:
     MetalRenderableResource(MetalBackend &backend):
@@ -92,17 +96,17 @@ public:
         return renderPassDescriptor;
     }
     
-    NS::SharedPtr<CA::MetalLayer> getSwapchain() {
+    const CAMetalLayerPtr& getSwapchain() const {
         return swapchain;
     }
     
 private:
     MetalBackend &rendererBackend;
-    NS::SharedPtr<MTL::CommandQueue> commandQueue;
-    NS::SharedPtr<MTL::CommandBuffer> commandBuffer;
-    NS::SharedPtr<MTL::RenderPassDescriptor> renderPassDescriptor;
-    NS::SharedPtr<CA::MetalDrawable> surface;
-    NS::SharedPtr<CA::MetalLayer> swapchain;
+    MTLCommandQueuePtr commandQueue;
+    MTLCommandBufferPtr commandBuffer;
+    MTLRenderPassDescriptorPtr renderPassDescriptor;
+    CAMetalDrawablePtr surface;
+    CAMetalLayerPtr swapchain;
     gfx::Texture2DPtr depthTexture;
     gfx::Texture2DPtr stencilTexture;
     mbgl::Size size;

platform/ios/BUILD.bazel

@@ -123,6 +123,7 @@ apple_xcframework(
     data = glob([
         "resources/*.lproj/**",
         "resources/*.xcassets/**",
+        "resources/metal-cpp-ignores.txt",
     ]),
     infoplists = ["info_plist"],
     ios = {
@@ -159,6 +160,7 @@ apple_resource_bundle(
     resources = glob([
         "resources/*.lproj/**",
         "resources/*.xcassets/**",
+        "resources/metal-cpp-ignores.txt",
     ]),
     visibility = ["//visibility:public"],
 )

platform/ios/app/MBXAppDelegate.m

@@ -3,14 +3,30 @@
 #import "MBXAppDelegate.h"
 #import "MBXViewController.h"
 
+#if __has_feature(undefined_behavior_sanitizer) || defined(__SANITIZE_UNDEFINED_BEHAVIOR__)
+#import "sanitizer/ubsan_interface.h"
+const char* __ubsan_default_options(void) {
+    static char default_opts[2 * PATH_MAX];
+    NSString* path = [[NSBundle bundleForClass:[MBXAppDelegate class]] pathForResource:@"metal-cpp-ignores" ofType:@"txt" inDirectory:@"Mapbox.bundle"];
+    NSString* opts = @"print_stacktrace=1,halt_on_error=1,report_error_type=1,verbosity=0";  // add ',help=1' to see available options
+    if (path) {
+        opts = [opts stringByAppendingFormat:@",suppressions=%@", path];
+    }
+    NSLog(@"Using ubsan options: %@", opts);
+
+    bzero(default_opts, sizeof(default_opts));
+    strncpy(default_opts, [opts UTF8String], sizeof(default_opts) - 1);
+    return default_opts;
+}
+#endif
+
 @interface MBXAppDelegate()
 
 @end
 
 @implementation MBXAppDelegate
 
-- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
-{
+- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
 #ifndef MLN_LOGGING_DISABLED
     [MLNLoggingConfiguration sharedConfiguration].loggingLevel = MLNLoggingLevelFault;
 #endif

platform/ios/resources/metal-cpp-ignores.txt

@@ -0,0 +1,7 @@
+# metal-cpp uses calls through null pointers
+# Note that the code must be compiled with `-fsanitize-recover=null` for this to work.
+null:vendor/metal-cpp/*
+
+# `NS::String*` implicit cast to `NS::Object*` in Context::createProgram
+alignment:src/mbgl/mtl/context.cpp
+