Delete old /dev/urandom backend for arc4random

HaikuOS doesn't need it anymore.

docs/CHANGELOG.md

@@ -18,6 +18,8 @@ Changes in libobsd master:
 - Add closefrom()
 - Include io.h in unistd.h on Windows to expose io.h's POSIX functions
 - Add C++ support
-- add timespeccmp(), timespecsub(), and other timeval/timespec macros from
+- Add timespeccmp(), timespecsub(), and other timeval/timespec macros from
   sys/time.h
+- Delete old /dev/urandom backend for arc4random now that HaikuOS doesn't need
+  it anymore
 

docs/CONTRIBUTING.md

@@ -1,5 +1,5 @@
 <!--
-Copyright (c) 2022-2023 Guilherme Janczak <[email protected]>
+Copyright (c) 2022-2024 Guilherme Janczak <[email protected]>
 
 Permission to use, copy, modify, and distribute this software for any
 purpose with or without fee is hereby granted, provided that the above
@@ -39,8 +39,7 @@ Every subdirectory under *src/* is named after a header. *stdlib/* for
 subdirectory belong to that header. Instead of piling up `#ifdef`s, I've chosen
 to split each "backend" that implements a function into its own file.
 
-Feature detection is used unless something is impossible to detect. For
-instance, there is some manual checking for Haiku.
+Feature detection is used unless something is impossible to detect.
 
 I don't intend to implement deprecated functions like `rindex()`, or silly
 functions like `getbsize()`. I trust the underlying platform, if it is buggy, fix

src/stdlib/meson.build

@@ -1,4 +1,4 @@
-# Copyright (c) 2022 Guilherme Janczak <[email protected]>
+# Copyright (c) 2022, 2024 Guilherme Janczak <[email protected]>
 #
 # Permission to use, copy, modify, and distribute this software for any
 # purpose with or without fee is hereby granted, provided that the above
@@ -39,33 +39,23 @@ foreach func, info : stdlib
 endforeach
 
 if stdlib['arc4random_buf'][2]
-  arc4random_backends = {
-    'getrandom': ['arc4random_buf_getrandom.c', '#include <sys/random.h>'],
-    'BCryptGenRandom': ['arc4random_buf_BCryptGenRandom.c',
-                        '''#include <windows.h>
-                        #include <bcrypt.h>'''],
-
-  }
-
-  if host_machine.system() == 'emscripten'
-    stdlib += {'arc4random_buf': ['arc4random_buf_emscripten.c',
-                                  'arc4random.3', true]}
-  elif host_machine.system() == 'haiku'
-    stdlib += {'arc4random_buf': ['arc4random_buf_dev_urandom.c',
-                                  'arc4random.3', true]}
-  endif
-
   bcrypt_dep = cc.find_library('bcrypt', required: false)
-  if bcrypt_dep.found()
+  bcrypt_pref = '''#include <windows.h>\n#include <bcrypt.h>'''
+  impl = ''
+  if bcrypt_dep.found() and cc.has_function('BCryptGenRandom',
+                                           prefix: bcrypt_pref,
+                                           deps: bcrypt_dep)
     deps += bcrypt_dep
+    impl = 'arc4random_buf_BCryptGenRandom.c'
+  elif host_machine.system() == 'emscripten'
+    impl = 'arc4random_buf_emscripten.c'
+  elif cc.has_function('getrandom', args: args,
+                       prefix: '#include <sys/random.h>')
+    impl = 'arc4random_buf_getrandom.c'
+  endif
+  if impl.length() != 0
+    stdlib += {'arc4random_buf': [impl, 'arc4random.3', true]}
   endif
-  foreach func, info : arc4random_backends
-    if cc.has_function(func, args: args, prefix: info[1],
-                       dependencies: deps)
-      stdlib += {'arc4random_buf': [info[0], 'arc4random.3', true]}
-      break
-    endif
-  endforeach
 endif
 
 stdlib_pragma = [] # daemon() needs stdlib_pragma early