Add bson library

src/CMakeLists.txt

@@ -1,5 +1,6 @@
 add_subdirectory(realm)
 add_subdirectory(external/IntelRDFPMathLib20U2)
+add_subdirectory(external/bson EXCLUDE_FROM_ALL)
 
 if (REALM_ENABLE_GEOSPATIAL)
     add_subdirectory(external/s2)

src/external/bson/CMakeLists.txt

@@ -0,0 +1,55 @@
+include(CheckFunctionExists)
+include(CheckStructHasMember)
+
+set(BSON_SRC
+  bcon.c
+  bson-clock.c
+  bson-decimal128.c
+  bson-error.c
+  bson-iso8601.c
+  bson-iter.c
+  bson-json.c
+  bson-keys.c
+  bson-memory.c
+  bson-oid.c
+  bson-reader.c
+  bson-string.c
+  bson-timegm.c
+  bson-utf8.c
+  bson-value.c
+  bson-version-functions.c
+  bson-writer.c
+  bson.c
+  common-b64.c
+  ../jsonsl/jsonsl.c
+)
+
+if(WIN32)
+	set(BSON_OS 2)
+else()
+	set(BSON_OS 1)
+endif()
+
+check_symbol_exists (snprintf stdio.h BSON_HAVE_SNPRINTF)
+CHECK_STRUCT_HAS_MEMBER ("struct timespec" tv_sec time.h BSON_HAVE_TIMESPEC)
+check_symbol_exists (gmtime_r time.h BSON_HAVE_GMTIME_R)
+check_function_exists (rand_r BSON_HAVE_RAND_R)
+check_include_file (strings.h BSON_HAVE_STRINGS_H)
+check_symbol_exists (strlcpy string.h BSON_HAVE_STRLCPY)
+check_include_file (stdbool.h BSON_HAVE_STDBOOL_H)
+check_symbol_exists (clock_gettime time.h BSON_HAVE_CLOCK_GETTIME)
+check_symbol_exists (strnlen string.h BSON_HAVE_STRNLEN)
+
+configure_file (
+   "${PROJECT_SOURCE_DIR}/src/external/bson/bson-config.h.in"
+   "${PROJECT_BINARY_DIR}/src/external/bson/bson-config.h"
+)
+
+add_library(Bson STATIC ${BSON_SRC})
+add_library(Realm::Bson ALIAS Bson)
+target_compile_definitions(Bson PRIVATE _GNU_SOURCE _XOPEN_SOURCE=700 BSON_COMPILATION)
+if (CMAKE_SYSTEM_NAME MATCHES "Darwin")
+  target_compile_definitions(Bson PRIVATE _DARWIN_C_SOURCE)
+endif()
+target_include_directories(Bson PUBLIC .. ${PROJECT_BINARY_DIR}/src/external)
+target_compile_definitions(Bson INTERFACE BSON_STATIC)

src/external/bson/README

@@ -0,0 +1 @@
+This code is copied from git@github.com:mongodb/mongo-c-driver.git version 1.25.0.