Turn on GCC's -Wredundant-tags, and drop the struct and enum keywords

AGENTS.md

@@ -552,10 +552,14 @@ configuration files.
   libstdc++ implements those comparisons with `operator<=>`, but `<chrono>`
   already includes `<compare>`, as the standard requires. Other wrong
   suggestions IWYU makes here:
-  - Removing `ibv-core.h` from a header that names the verbs types only as
-    `struct ibv_pd *` and the like. Without a prior declaration, that
-    declares a new `struct` in the enclosing namespace (`hipObj::ibv_pd`,
-    not libibverbs' `::ibv_pd`), so keep the include.
+  - Replacing `ibv-core.h` with forward declarations of the verbs types
+    (`struct ibv_pd;` and the like) in a header that uses them only through
+    pointers, such as [`src/buffer.h`](src/buffer.h) and
+    [`src/common/ibv-wrapper.h`](src/common/ibv-wrapper.h). `ibv-core.h`
+    declares them in the global namespace, as libibverbs does. A copy of
+    the declaration only repeats it, and one inside `namespace hipObj`
+    declares a different type (`hipObj::ibv_pd`, not `::ibv_pd`), so keep
+    the include.
   - Removing `<cstdint>` from `src/hipobj.cpp` because the public header
     includes `<stdint.h>`. C++ code includes `<cstdint>` (see
     [C++ code](#c-code)).

cmake/HIPOBJGNUCompilerOptions.cmake

@@ -121,7 +121,7 @@ function(hipobj_get_gnu_warning_flags outvar compiler_version)
       # Misc warnings
       -Warith-conversion
       -Wmismatched-tags
-      #-Wredundant-tags # TODO: Fix issues
+      -Wredundant-tags
       ${flags}
     )
   endif()

examples/s3_curl_ops.cpp

@@ -28,22 +28,22 @@ struct CurlEasyDeleter {
 };
 
 struct CurlSlistDeleter {
-    void operator()(struct curl_slist *list) const noexcept
+    void operator()(curl_slist *list) const noexcept
     {
         curl_slist_free_all(list);
     }
 };
 
 using CurlEasyPtr  = std::unique_ptr<CURL, CurlEasyDeleter>;
-using CurlSlistPtr = std::unique_ptr<struct curl_slist, CurlSlistDeleter>;
+using CurlSlistPtr = std::unique_ptr<curl_slist, CurlSlistDeleter>;
 
 // curl_slist_append() returns the head of the list, which is a new node
 // only when the list was empty, or NULL on failure without freeing the
 // list.
 bool
 appendHeader(CurlSlistPtr &list, const char *header)
 {
-    struct curl_slist *head = curl_slist_append(list.get(), header);
+    curl_slist *head = curl_slist_append(list.get(), header);
     if (head == nullptr) {
         return false;
     }

src/buffer.cpp

@@ -75,8 +75,8 @@ namespace {
 } // namespace
 
 IbvMrPtr
-registerDeviceMemory(const Verbs &verbs, const HipRuntime &runtime, struct ibv_pd *pd, void *addr,
-                     size_t length, int access, const DmabufPolicy &policy)
+registerDeviceMemory(const Verbs &verbs, const HipRuntime &runtime, ibv_pd *pd, void *addr, size_t length,
+                     int access, const DmabufPolicy &policy)
 {
     /* Whether a given GPU can export a dma-buf and a given NIC can register
      * it is answered by trying: both calls report their own failure and
@@ -180,7 +180,7 @@ BufferMap::insert(uintptr_t key, std::shared_ptr<const BufEntry> entry)
 }
 
 BufferMap::RegisterResult
-BufferMap::registerBuffer(void *devPtr, size_t size, struct ibv_pd *pd)
+BufferMap::registerBuffer(void *devPtr, size_t size, ibv_pd *pd)
 {
     if (size > MAX_MR_SIZE) {
         return RegisterResult::Failed;
@@ -236,7 +236,7 @@ BufferMap::registerBuffer(void *devPtr, size_t size, struct ibv_pd *pd)
 }
 
 BufferMap::RegisterResult
-BufferMap::registerHostBuffer(void *hostPtr, size_t size, struct ibv_pd *pd)
+BufferMap::registerHostBuffer(void *hostPtr, size_t size, ibv_pd *pd)
 {
     if (size > MAX_MR_SIZE) {
         return RegisterResult::Failed;

src/buffer.h

@@ -38,7 +38,7 @@ struct DmabufPolicy {
  * GPU memory. Otherwise, or when either step fails, it registers the
  * memory as host memory, which fails for GPU memory. Null when nothing
  * registers. */
-IbvMrPtr registerDeviceMemory(const Verbs &verbs, const HipRuntime &runtime, struct ibv_pd *pd, void *addr,
+IbvMrPtr registerDeviceMemory(const Verbs &verbs, const HipRuntime &runtime, ibv_pd *pd, void *addr,
                               size_t length, int access, const DmabufPolicy &policy);
 
 /* Frees a host staging buffer through the runtime whose hostMalloc()
@@ -146,9 +146,9 @@ class BufferMap {
      * holding the map's lock. When two threads register the same address
      * at once, one gets Registered, and the other AlreadyRegistered, and
      * its registration is released. */
-    [[nodiscard]] RegisterResult registerBuffer(void *devPtr, size_t size, struct ibv_pd *pd)
+    [[nodiscard]] RegisterResult registerBuffer(void *devPtr, size_t size, ibv_pd *pd)
         HIPOBJ_REQUIRES(!mutex_);
-    [[nodiscard]] RegisterResult registerHostBuffer(void *hostPtr, size_t size, struct ibv_pd *pd)
+    [[nodiscard]] RegisterResult registerHostBuffer(void *hostPtr, size_t size, ibv_pd *pd)
         HIPOBJ_REQUIRES(!mutex_);
     /* Removes the entry, and releases its registration and any staging
      * buffer without holding the map's lock */