build(thirdparty): replace CRoaring submodule with amalgamation (~292M -> ~1MB)

.gitmodules

@@ -19,9 +19,6 @@
 	path = thirdparty/arrow/apache-arrow-21.0.0
 	url = https://github.com/apache/arrow.git
 	ignore = all
-[submodule "thirdparty/CRoaring/CRoaring-2.0.4"]
-	path = thirdparty/CRoaring/CRoaring-2.0.4
-	url = https://github.com/RoaringBitmap/CRoaring.git
 [submodule "thirdparty/glog/glog-0.5.0"]
 	path = thirdparty/glog/glog-0.5.0
 	url = https://github.com/google/glog.git

thirdparty/CRoaring/CMakeLists.txt

@@ -1,24 +1,62 @@
-set(ENABLE_ROARING_TESTS OFF CACHE BOOL "Disable testing in CRoaring" FORCE)
-if(MSVC)
-    set(ROARING_BUILD_STATIC ON CACHE BOOL "" FORCE)
-endif()
+# CRoaring v2.0.4 - integrated as a single-file amalgamation build.
+#
+# We deliberately do NOT pull the upstream repository as a git submodule
+# anymore: it ships ~292M of benchmarks/test data that we never build, which
+# made `git submodule update --init --recursive` painfully slow and bloated
+# the local checkout.
+#
+# Instead, the official amalgamation produced by CRoaring's release pipeline
+# (https://github.com/RoaringBitmap/CRoaring/releases/tag/v2.0.4) is checked
+# into amalgamation/:
+#
+#   amalgamation/roaring.c          - single C TU containing the entire library
+#   amalgamation/roaring.h          - public C API (from official release)
+#   amalgamation/roaring.hh         - public C++ wrapper (from official release)
+#   amalgamation/roaring64map.hh    - 64-bit C++ wrapper (from cpp/ in tarball)
+#   amalgamation/include/roaring/roaring.h
+#                                   - identical to roaring.h, exposed under the
+#                                     historical <roaring/roaring.h> path so
+#                                     existing callers keep working.
+#
+# To upgrade, replace these files with the assets from a newer release tag
+# (and grab cpp/roaring64map.hh from the source tarball if it is still split).
+set(_ROARING_AMAL_DIR ${CMAKE_CURRENT_SOURCE_DIR}/amalgamation)
+
+add_library(roaring STATIC ${_ROARING_AMAL_DIR}/roaring.c)
+set_target_properties(roaring PROPERTIES
+    POSITION_INDEPENDENT_CODE ON
+    ARCHIVE_OUTPUT_DIRECTORY ${EXTERNAL_LIB_DIR}
+)
 
-set(_SAVED_CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_ARCHIVE_OUTPUT_DIRECTORY})
-set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${EXTERNAL_LIB_DIR})
-add_subdirectory(CRoaring-2.0.4)
-set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${_SAVED_CMAKE_ARCHIVE_OUTPUT_DIRECTORY})
-unset(_SAVED_CMAKE_ARCHIVE_OUTPUT_DIRECTORY)
+# Two include roots:
+#   - amalgamation/         -> <roaring.h>, <roaring.hh>, <roaring64map.hh>
+#   - amalgamation/include/ -> <roaring/roaring.h>  (legacy path used in code)
+target_include_directories(roaring PUBLIC
+    $<BUILD_INTERFACE:${_ROARING_AMAL_DIR}>
+    $<BUILD_INTERFACE:${_ROARING_AMAL_DIR}/include>
+)
 
-if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
-    target_compile_options(roaring PRIVATE 
-        -Wno-unused-parameter 
+# The amalgamation is plain C11; the C++ wrappers in roaring.hh require C++11+.
+target_compile_features(roaring PUBLIC c_std_11)
+
+# Silence warnings that come from the third-party amalgamation itself; we do
+# not want them polluting our build.
+if(CMAKE_C_COMPILER_ID STREQUAL "GNU" OR CMAKE_C_COMPILER_ID STREQUAL "Clang"
+   OR CMAKE_C_COMPILER_ID STREQUAL "AppleClang")
+    target_compile_options(roaring PRIVATE
+        -Wno-unused-parameter
         -Wno-unused-but-set-variable
+        -Wno-unused-function
     )
 endif()
 
-get_target_property(roaring_SOURCE_DIR roaring INTERFACE_SOURCE_DIR)
-set(ROARING_FOUND TRUE PARENT_SCOPE)
-set(ROARING_INCLUDE_DIR ${roaring_SOURCE_DIR}/include PARENT_SCOPE)
-set(ROARING_INCLUDE_DIRS ${roaring_SOURCE_DIR}/include PARENT_SCOPE)
-set(ROARING_LIBRARY $<TARGET_FILE:roaring> PARENT_SCOPE)
-set(ROARING_LIBRARIES $<TARGET_FILE:roaring> PARENT_SCOPE)
+# Preserve the legacy ROARING_* variables so any consumer that still reads
+# them (instead of linking the `roaring` target directly) keeps working.
+set(ROARING_FOUND        TRUE                          PARENT_SCOPE)
+set(ROARING_INCLUDE_DIR  ${_ROARING_AMAL_DIR}          PARENT_SCOPE)
+set(ROARING_INCLUDE_DIRS ${_ROARING_AMAL_DIR}
+                         ${_ROARING_AMAL_DIR}/include  PARENT_SCOPE)
+set(ROARING_LIBRARY      $<TARGET_FILE:roaring>        PARENT_SCOPE)
+set(ROARING_LIBRARIES    $<TARGET_FILE:roaring>        PARENT_SCOPE)
+
+unset(_ROARING_AMAL_DIR)