Remove all per-OS defines apart from _WINDOWS.

These are all unused and shouldn't be needed. Mostly we need
something for differentiating between POSIX and non-POSIX
(until we can reduce some of those differences as well).

We shouldn't need to modify the build system to build on a new
OS if it is basically a Unix and is supported by cmake.

CMakeLists.txt

@@ -178,32 +178,10 @@ set(CMAKE_CXX_STANDARD_REQUIRED ON)
 ################################################################################
 # Platform detection
 ################################################################################
-if (CMAKE_SYSTEM_NAME STREQUAL "Linux")
-  message(STATUS "Platform: Linux")
-  list(APPEND Z3_COMPONENT_CXX_DEFINES "-D_LINUX_")
-elseif (CMAKE_SYSTEM_NAME STREQUAL "Android")
-  message(STATUS "Platform: Android")
-  list(APPEND Z3_COMPONENT_CXX_DEFINES "-D_ANDROID_")
-elseif (CMAKE_SYSTEM_NAME MATCHES "GNU")
-  message(STATUS "Platform: GNU/Hurd")
-  list(APPEND Z3_COMPONENT_CXX_DEFINES "-D_HURD_")
-elseif (CMAKE_SYSTEM_NAME STREQUAL "Darwin")
+if (CMAKE_SYSTEM_NAME STREQUAL "Darwin")
   if (TARGET_ARCHITECTURE STREQUAL "arm64")
     set(CMAKE_OSX_ARCHITECTURES "arm64")
   endif()
-  message(STATUS "Platform: Darwin")
-elseif (CMAKE_SYSTEM_NAME MATCHES "FreeBSD")
-  message(STATUS "Platform: FreeBSD")
-  list(APPEND Z3_COMPONENT_CXX_DEFINES "-D_FREEBSD_")
-elseif (CMAKE_SYSTEM_NAME MATCHES "NetBSD")
-  message(STATUS "Platform: NetBSD")
-  list(APPEND Z3_COMPONENT_CXX_DEFINES "-D_NetBSD_")
-elseif (CMAKE_SYSTEM_NAME MATCHES "OpenBSD")
-  message(STATUS "Platform: OpenBSD")
-  list(APPEND Z3_COMPONENT_CXX_DEFINES "-D_OPENBSD_")
-elseif (CYGWIN)
-  message(STATUS "Platform: Cygwin")
-  list(APPEND Z3_COMPONENT_CXX_DEFINES "-D_CYGWIN")
 elseif (WIN32)
   message(STATUS "Platform: Windows")
   list(APPEND Z3_COMPONENT_CXX_DEFINES "-D_WINDOWS")
@@ -216,8 +194,6 @@ elseif (EMSCRIPTEN)
     "-s DISABLE_EXCEPTION_CATCHING=0"
     "-s ERROR_ON_UNDEFINED_SYMBOLS=1"
   )
-else()
-  message(FATAL_ERROR "Platform \"${CMAKE_SYSTEM_NAME}\" not recognised")
 endif()
 
 list(APPEND Z3_COMPONENT_EXTRA_INCLUDE_DIRS

scripts/mk_util.py

@@ -2594,46 +2594,30 @@ def mk_config():
             SO_EXT         = '.dylib'
             SLIBFLAGS      = '-dynamiclib'
         elif sysname == 'Linux':
-            CXXFLAGS       = '%s -D_LINUX_' % CXXFLAGS
-            OS_DEFINES     = '-D_LINUX_'
             SO_EXT         = '.so'
             SLIBFLAGS      = '-shared'
             SLIBEXTRAFLAGS = '%s -Wl,-soname,libz3.so' % SLIBEXTRAFLAGS
         elif sysname == 'GNU':
-            CXXFLAGS       = '%s -D_HURD_' % CXXFLAGS
-            OS_DEFINES     = '-D_HURD_'
             SO_EXT         = '.so'
             SLIBFLAGS      = '-shared'
         elif sysname == 'FreeBSD':
-            CXXFLAGS       = '%s -D_FREEBSD_' % CXXFLAGS
-            OS_DEFINES     = '-D_FREEBSD_'
             SO_EXT         = '.so'
             SLIBFLAGS      = '-shared'
             SLIBEXTRAFLAGS = '%s -Wl,-soname,libz3.so' % SLIBEXTRAFLAGS
         elif sysname == 'NetBSD':
-            CXXFLAGS       = '%s -D_NETBSD_' % CXXFLAGS
-            OS_DEFINES     = '-D_NETBSD_'
             SO_EXT         = '.so'
             SLIBFLAGS      = '-shared'
         elif sysname == 'OpenBSD':
-            CXXFLAGS       = '%s -D_OPENBSD_' % CXXFLAGS
-            OS_DEFINES     = '-D_OPENBSD_'
             SO_EXT         = '.so'
             SLIBFLAGS      = '-shared'
         elif sysname  == 'SunOS':
-            CXXFLAGS       = '%s -D_SUNOS_' % CXXFLAGS
-            OS_DEFINES     = '-D_SUNOS_'
             SO_EXT         = '.so'
             SLIBFLAGS      = '-shared'
             SLIBEXTRAFLAGS = '%s -mimpure-text' % SLIBEXTRAFLAGS
         elif sysname.startswith('CYGWIN'):
-            CXXFLAGS       = '%s -D_CYGWIN' % CXXFLAGS
-            OS_DEFINES     = '-D_CYGWIN'
             SO_EXT         = '.dll'
             SLIBFLAGS      = '-shared'
         elif sysname.startswith('MSYS_NT') or sysname.startswith('MINGW'):
-            CXXFLAGS       = '%s -D_MINGW' % CXXFLAGS
-            OS_DEFINES     = '-D_MINGW'
             SO_EXT         = '.dll'
             SLIBFLAGS      = '-shared'
             EXE_EXT        = '.exe'