Inline functions that return static references must have default visibility

doxygen/Doxyfile

@@ -2176,7 +2176,11 @@ INCLUDE_FILE_PATTERNS  =
 # recursively expanded use the := operator instead of the = operator.
 # This tag requires that the tag ENABLE_PREPROCESSING is set to YES.
 
-PREDEFINED             = RMM_NAMESPACE=rmm RMM_EXPORT
+# These need to be kept in sync with set in rmm/detail/export.hpp
+# Since we are excluding detail files in EXCLUDE_PATTERNS there
+# appears to be no way of getting doxygen to still parse that file and
+# make the definitions available via the preprocessor :(
+PREDEFINED             = RMM_EXPORT RMM_HIDDEN RMM_NAMESPACE=rmm
 
 # If the MACRO_EXPANSION and EXPAND_ONLY_PREDEF tags are set to YES then this
 # tag can be used to specify a list of macro names that should be expanded. The
@@ -2185,7 +2189,7 @@ PREDEFINED             = RMM_NAMESPACE=rmm RMM_EXPORT
 # definition found in the source code.
 # This tag requires that the tag ENABLE_PREPROCESSING is set to YES.
 
-EXPAND_AS_DEFINED      = RMM_NAMESPACE
+EXPAND_AS_DEFINED      =
 
 # If the SKIP_FUNCTION_MACROS tag is set to YES then doxygen's preprocessor will
 # remove all references to function-like macros that are alone on a line, have

include/rmm/detail/export.hpp

@@ -24,4 +24,5 @@
 #else
 #define RMM_EXPORT
 #define RMM_HIDDEN
+#define RMM_NAMESPACE rmm
 #endif

include/rmm/logger.hpp

@@ -107,7 +107,7 @@ struct bytes {
  *
  * @return spdlog::logger& The logger.
  */
-inline spdlog::logger& logger()
+RMM_EXPORT inline spdlog::logger& logger()
 {
   static detail::logger_wrapper wrapped{};
   return wrapped.logger_;

include/rmm/mr/device/per_device_resource.hpp

@@ -90,14 +90,20 @@ namespace mr {
 
 namespace detail {
 
+// These symbols must have default visibility so that when they are
+// referenced in multiple different DSOs the linker correctly
+// determines that there is only a single unique reference to the
+// function symbols (and hence they return unique static references
+// across different DSOs).
+// See also https://github.com/rapidsai/rmm/issues/826
 /**
  * @brief Returns a pointer to the initial resource.
  *
  * Returns a global instance of a `cuda_memory_resource` as a function local static.
  *
  * @return Pointer to the static cuda_memory_resource used as the initial, default resource
  */
-inline device_memory_resource* initial_resource()
+RMM_EXPORT inline device_memory_resource* initial_resource()
 {
   static cuda_memory_resource mr{};
   return &mr;
@@ -106,13 +112,12 @@ inline device_memory_resource* initial_resource()
 /**
  * @briefreturn{Reference to the lock}
  */
-inline std::mutex& map_lock()
+RMM_EXPORT inline std::mutex& map_lock()
 {
   static std::mutex map_lock;
   return map_lock;
 }
 
-// This symbol must have default visibility, see: https://github.com/rapidsai/rmm/issues/826
 /**
  * @briefreturn{Reference to the map from device id -> resource}
  */