mdbx: auto-define _GNU_SOURCE under control of MDBX_DISABLE_GNU_SOURCE.

Change-Id: I314d88b86517e3c44ad35fe02d3a27cb987c6d60

CMakeLists.txt

@@ -291,7 +291,11 @@ add_mdbx_option(MDBX_ALLOY_BUILD "Build MDBX library as single object file" ON)
 add_mdbx_option(MDBX_TXN_CHECKOWNER "Checking transaction matches the calling thread inside libmdbx's API" ON)
 add_mdbx_option(MDBX_TXN_CHECKPID "Paranoid checking PID inside libmdbx's API" AUTO)
 mark_as_advanced(MDBX_TXN_CHECKPID)
-if(APPLE)
+if(${CMAKE_SYSTEM_NAME} STREQUAL "Linux")
+  add_mdbx_option(MDBX_DISABLE_GNU_SOURCE "Don't use nonstandard GNU/Linux extension functions" OFF)
+  mark_as_advanced(MDBX_DISABLE_GNU_SOURCE)
+endif()
+if(${CMAKE_SYSTEM_NAME} STREQUAL "Darwin")
   add_mdbx_option(MDBX_OSX_SPEED_INSTEADOF_DURABILITY "Disable use fcntl(F_FULLFSYNC) in favor of speed" OFF)
   mark_as_advanced(MDBX_OSX_SPEED_INSTEADOF_DURABILITY)
 endif()

GNUmakefile

@@ -20,7 +20,7 @@ suffix  ?=
 
 CC      ?= gcc
 LD      ?= ld
-MDBX_OPTIONS ?= -D_GNU_SOURCE=1 -DNDEBUG=1
+MDBX_OPTIONS ?= -DNDEBUG=1
 CFLAGS  ?= -O2 -g3 -Wall -Werror -Wextra -ffunction-sections -fPIC -fvisibility=hidden -std=gnu11 -pthread
 
 # LY: '--no-as-needed,-lrt' for ability to built with modern glibc, but then run with the old

src/elements/config.h.in

@@ -28,6 +28,7 @@
 /* POSIX */
 #cmakedefine01 MDBX_USE_ROBUST
 #cmakedefine01 MDBX_USE_OFDLOCKS
+#cmakedefine01 MDBX_DISABLE_GNU_SOURCE
 
 /* Simulate "AUTO" values of tristate options */
 #cmakedefine MDBX_TXN_CHECKPID_AUTO

src/elements/core.c

@@ -15628,6 +15628,11 @@ __dll_export
     " MDBX_TXN_CHECKPID=" STRINGIFY(MDBX_TXN_CHECKPID)
     " MDBX_TXN_CHECKOWNER=" STRINGIFY(MDBX_TXN_CHECKOWNER)
     " MDBX_64BIT_ATOMIC=" STRINGIFY(MDBX_64BIT_ATOMIC)
+#ifdef _GNU_SOURCE
+    " _GNU_SOURCE=YES"
+#else
+    " _GNU_SOURCE=NO"
+#endif /* _GNU_SOURCE */
 #ifdef __APPLE__
     " MDBX_OSX_SPEED_INSTEADOF_DURABILITY=" STRINGIFY(MDBX_OSX_SPEED_INSTEADOF_DURABILITY)
 #endif /* MacOS */

src/elements/internals.h

@@ -49,6 +49,15 @@
 #   define MDBX_INTERNAL_VAR extern
 #endif /* MDBX_ALLOY */
 
+#ifndef MDBX_DISABLE_GNU_SOURCE
+#define MDBX_DISABLE_GNU_SOURCE 0
+#endif
+#if MDBX_DISABLE_GNU_SOURCE
+#undef _GNU_SOURCE
+#elif defined(__linux__) || defined(__gnu_linux__)
+#define _GNU_SOURCE
+#endif
+
 /*----------------------------------------------------------------------------*/
 
 /* Should be defined before any includes */

src/elements/osal.c

@@ -1275,10 +1275,7 @@ retry_mapview:;
   return rc;
 #else
   if (limit != map->length) {
-#if defined(_GNU_SOURCE) &&                                                    \
-    !(defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) ||   \
-      defined(__BSD__) || defined(__NETBSD__) || defined(__bsdi__) ||          \
-      defined(__DragonFly__) || defined(__APPLE__) || defined(__MACH__))
+#if defined(_GNU_SOURCE) && (defined(__linux__) || defined(__gnu_linux__))
     void *ptr = mremap(map->address, map->length, limit,
                        /* LY: in case changing the mapping size calling code
                           must guarantees the absence of competing threads, and
@@ -1292,7 +1289,7 @@ retry_mapview:;
     map->length = limit;
 #else
     return MDBX_RESULT_TRUE;
-#endif /* mremap() <= _GNU_SOURCE && !__FreeBSD__ */
+#endif /* _GNU_SOURCE && __linux__ */
   }
   return (flags & MDBX_RDONLY) ? MDBX_SUCCESS : mdbx_ftruncate(map->fd, size);
 #endif

src/tools/CMakeLists.txt

@@ -13,7 +13,7 @@ set(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)
 # the RPATH to be used when installing, but only if it's not a system directory
 list(FIND CMAKE_PLATFORM_IMPLICIT_LINK_DIRECTORIES "${CMAKE_INSTALL_PREFIX}/lib" isSystemDir)
 if(isSystemDir EQUAL -1)
-  if(APPLE)
+  if(${CMAKE_SYSTEM_NAME} STREQUAL "Darwin")
     set(CMAKE_INSTALL_RPATH "@executable_path/../lib")
   else()
     set(CMAKE_INSTALL_RPATH "\$ORIGIN/../lib")