CDRIVER-4249 Apply _DEFAULT_SOURCE to all subdirectories (#920)

* Remove deprecated feature test macro _BSD_SOURCE
* Reduce language extensions to those specified by _DEFAULT_SOURCE
* Apply _DEFAULT_SOURCE to all subdirectories
* Remove explicit feature test macros from Evergreen tasks
* Address missing inclusion of unistd.h during zlib bundle compilation

Author: eramongodb

.evergreen/config.yml

@@ -1023,7 +1023,7 @@ tasks:
       shell: bash
       script: |-
         set -o errexit
-        export CFLAGS="-std=c11 -D_XOPEN_SOURCE=600"
+        export CFLAGS="-std=c11"
         export DEBUG="ON"
         CC='${CC}' MARCH='${MARCH}' sh .evergreen/compile.sh
   - func: upload build
@@ -1041,7 +1041,7 @@ tasks:
       shell: bash
       script: |-
         set -o errexit
-        export CFLAGS="-std=c99 -D_XOPEN_SOURCE=600"
+        export CFLAGS="-std=c99"
         export DEBUG="ON"
         CC='${CC}' MARCH='${MARCH}' sh .evergreen/compile.sh
   - func: upload build
@@ -1059,7 +1059,7 @@ tasks:
       shell: bash
       script: |-
         set -o errexit
-        export CFLAGS="-std=c89 -D_POSIX_C_SOURCE=200112L -pedantic"
+        export CFLAGS="-std=c89 -pedantic"
         export DEBUG="ON"
         CC='${CC}' MARCH='${MARCH}' sh .evergreen/compile.sh
   - func: upload build

CMakeLists.txt

@@ -235,6 +235,11 @@ set (CMAKE_MACOSX_RPATH ON)
 # silence a CMake 3.11 warning that the old behavior is deprecated.
 cmake_policy (SET CMP0042 NEW)
 
+# https://www.gnu.org/software/libc/manual/html_node/Feature-Test-Macros.html
+# Enable features from POSIX.1-2008 as well as certain BSD and SVID features.
+add_definitions (-D_DEFAULT_SOURCE)
+list (APPEND CMAKE_REQUIRED_DEFINITIONS -D_DEFAULT_SOURCE)
+
 add_subdirectory (src/common)
 
 if (NOT USING_SYSTEM_BSON)
@@ -253,10 +258,6 @@ if (MSVC)
    add_definitions (-D_CRT_SECURE_NO_WARNINGS)
 endif ()
 
-add_definitions (-D_GNU_SOURCE)
-add_definitions (-D_BSD_SOURCE)
-add_definitions (-D_DEFAULT_SOURCE)
-
 if (ENABLE_MONGOC)
 
    if (ENABLE_TESTS AND NOT MONGOC_ENABLE_STATIC_BUILD)

build/evergreen_config_lib/tasks.py

@@ -191,13 +191,13 @@ def __init__(self, task_name, suffix_commands, orchestration=True, **kwargs):
     CompileTask('debug-compile-lto-thin', CFLAGS='-flto=thin'),
     SpecialTask('debug-compile-c11',
                 tags=['debug-compile', 'c11', 'stdflags'],
-                CFLAGS='-std=c11 -D_XOPEN_SOURCE=600'),
+                CFLAGS='-std=c11'),
     SpecialTask('debug-compile-c99',
                 tags=['debug-compile', 'c99', 'stdflags'],
-                CFLAGS='-std=c99 -D_XOPEN_SOURCE=600'),
+                CFLAGS='-std=c99'),
     SpecialTask('debug-compile-c89',
                 tags=['debug-compile', 'c89', 'stdflags'],
-                CFLAGS='-std=c89 -D_POSIX_C_SOURCE=200112L -pedantic'),
+                CFLAGS='-std=c89 -pedantic'),
     SpecialTask('debug-compile-valgrind',
                 tags=['debug-compile', 'valgrind'],
                 SASL='OFF',

src/libbson/CMakeLists.txt

@@ -35,19 +35,6 @@ set (BSON_API_VERSION 1.0)
 set (CPACK_PACKAGE_VERSION_MAJOR ${BSON_MAJOR_VERSION})
 set (CPACK_PACKAGE_VERSION_MINOR ${BSON_MINOR_VERSION})
 
-# Enable X/Open 7.0 / POSIX 2008
-if (NOT WIN32)
-   add_compile_options(-D_XOPEN_SOURCE=700)
-   # Add to CMAKE_REQUIRED_DEFINITIONS to apply to CHECK_SYMBOL_EXISTS.
-   set (CMAKE_REQUIRED_DEFINITIONS "${CMAKE_REQUIRED_DEFINITIONS} -D_XOPEN_SOURCE=700")
-endif ()
-# Enable macOS extensions for strlcpy and arc4random.
-if (APPLE)
-   add_compile_options(-D_DARWIN_C_SOURCE=1)
-   # Add to CMAKE_REQUIRED_DEFINITIONS to apply to CHECK_SYMBOL_EXISTS.
-   set (CMAKE_REQUIRED_DEFINITIONS "${CMAKE_REQUIRED_DEFINITIONS} -D_DARWIN_C_SOURCE=1")
-endif ()
-
 include (CPack)
 TEST_BIG_ENDIAN (BSON_BIG_ENDIAN)
 

src/libmongoc/CMakeLists.txt

@@ -99,6 +99,12 @@ if (NOT ENABLE_ZLIB STREQUAL "OFF")
    include (CheckIncludeFiles)
    check_include_files ("unistd.h" HAVE_UNISTD_H)
    check_include_files ("stdarg.h" HAVE_STDARG_H)
+   if (HAVE_UNISTD_H)
+      add_definitions (-DHAVE_UNISTD_H)
+   endif ()
+   if (HAVE_STDARG_H)
+      add_definitions (-DHAVE_STDARG_H)
+   endif ()
    set (MONGOC_ENABLE_COMPRESSION 1)
    set (MONGOC_ENABLE_COMPRESSION_ZLIB 1)
 else ()