Adopt new dyld SPIs to introspect the shared cache.

lldb/source/Host/macosx/objcxx/HostInfoMacOSX.mm

@@ -35,6 +35,10 @@
 #include <CoreFoundation/CoreFoundation.h>
 #include <Foundation/Foundation.h>
 #include <mach-o/dyld.h>
+#if __has_include(<mach-o/dyld_introspection.h>)
+#include <mach-o/dyld_introspection.h>
+#define SDK_HAS_NEW_DYLD_INTROSPECTION_SPIS
+#endif
 #include <objc/objc-auto.h>
 
 // These are needed when compiling on systems
@@ -537,6 +541,41 @@ static void ParseOSVersion(llvm::VersionTuple &version, NSString *Key) {
 }
 
 SharedCacheInfo::SharedCacheInfo() {
+#if defined(SDK_HAS_NEW_DYLD_INTROSPECTION_SPIS)
+  if (__builtin_available(macOS 12, *)) {
+    if (dyld_process_create_for_current_task) {
+      auto dyld_process = dyld_process_create_for_current_task();
+      auto snapshot =
+          dyld_process_snapshot_create_for_process(dyld_process, nullptr);
+      auto shared_cache = dyld_process_snapshot_get_shared_cache(snapshot);
+      assert(dyld_process && snapshot && shared_cache);
+
+      dyld_shared_cache_for_each_image(shared_cache, ^(dyld_image_t image) {
+        __block uint64_t minVmAddr = UINT64_MAX;
+        __block uint64_t maxVmAddr = 0;
+        uuid_t uuidStore;
+        __block uuid_t *uuid = &uuidStore;
+
+        dyld_image_for_each_segment_info(image, ^(const char *segmentName,
+                                                  uint64_t vmAddr,
+                                                  uint64_t vmSize, int perm) {
+          minVmAddr = std::min(minVmAddr, vmAddr);
+          maxVmAddr = std::max(maxVmAddr, vmAddr + vmSize);
+          dyld_image_copy_uuid(image, uuid);
+        });
+        assert(minVmAddr != UINT_MAX);
+        assert(maxVmAddr != 0);
+        m_images[dyld_image_get_installname(image)] = SharedCacheImageInfo{
+            UUID::fromData(uuid, 16),
+            std::make_shared<DataBufferUnowned>((uint8_t *)minVmAddr,
+                                                maxVmAddr - minVmAddr)};
+      });
+      dyld_process_snapshot_dispose(snapshot);
+      return;
+    }
+  }
+#endif
+
   size_t shared_cache_size;
   uint8_t *shared_cache_start =
       _dyld_get_shared_cache_range(&shared_cache_size);