Get it working

ent.c

@@ -1,28 +1,14 @@
-#include <ent.h>
+#include <ent/ent.h>
 
-#include <assert.h>
-
-#include "config.h"
-
-#if defined(USE_GETENTROPY)
-# include <unistd.h>
-# if defined(__APPLE__) || defined(__linux__)
-#   include <sys/random.h>
-# endif
-# define getentropy_impl getentropy
-#elif defined(USE_URANDOM)
+#if defined(ENT_USE_URANDOM)
+# include <assert.h>
 # include <fcntl.h>
 # include <sys/types.h>
 # include <unistd.h>
-#else
-# error "port: getentropy"
-#endif
 
 
-#if defined(USE_URANDOM)
-
-static int
-getentropy_impl(void* buf, size_t buflen)
+int
+ent_getentropy(void* buf, size_t buflen)
 {
   int fd;
 
@@ -38,10 +24,4 @@ getentropy_impl(void* buf, size_t buflen)
   return 0;
 }
 
-#endif
-
-int
-ent_getentropy(void *buf, size_t buflen)
-{
-  return getentropy_impl(buf, buflen);
-}
+#endif /* ENT_USE_URANDOM */

include/ent/ent.h

@@ -1,10 +1,21 @@
 #ifndef _ENT_H
 #define _ENT_H
 
-#include <stddef.h>
-
 #include <ent/config.h>
 
+#if defined(ENT_GETENTROPY)
+# if defined(ENT_GE_SYSRANDOM)
+#   include <stddef.h>
+#   include <inttypes.h>  /* OSX sys/random.h needs Availability.h from this */
+#   include <sys/random.h>
+# elif defined(ENT_GE_UNISTD)
+#   include <unistd.h>
+# else
+#   error "libent: this shouldn't happen"
+# endif
+# define ent_getentropy getentropy
+#elif defined(ENT_URANDOM)
+
 /*
  * Fills buf with high-quality entropy.
  *
@@ -16,4 +27,8 @@
 int
 ent_getentropy(void* buf, size_t buflen);
 
+#else
+# error "libent: platform not supported"
+#endif
+
 #endif /* _ENT_H */

include/ent/meson.build

@@ -1,19 +1,29 @@
 conf_data = configuration_data()
 compiler = meson.get_compiler('c')
 
-code = '''#include <unistd.h>
+code = '''#include <stddef.h>
+#include <inttypes.h> /* OSX sys/random.h needs Availability.h from this */
 #include <sys/random.h>
 int main() { return getentropy((void*)0, 0); }
 '''
-have_getentropy = compiler.links(code, name : 'system getentropy')
-conf_data.set('ENT_USE_GETENTROPY', have_getentropy)
+sysrandom = compiler.links(code, name : 'getentropy in sys/random.h')
+conf_data.set('ENT_GE_SYSRANDOM', sysrandom)
+
+code = '''#include <unistd.h>
+int main() { return getentropy((void*)0, 0); }
+'''
+unistd = compiler.links(code, name : 'getentropy is in unistd.h')
+conf_data.set('ENT_GE_UNISTD', unistd)
+
+have_getentropy = sysrandom or unistd
+conf_data.set('ENT_GETENTROPY', have_getentropy)
 
 if not have_getentropy
   code = '''#include <fcntl.h>
   int main() { return -1 != open("/dev/urandom", O_RDONLY) ? 0 : 1; }
   '''
-  use_urandom = compiler.run(code, name : 'open /dev/urandom')
-  conf_data.set('ENT_USE_URANDOM', use_urandom.returncode() == 0)
+  use_urandom = compiler.run(code, name : 'can open /dev/urandom')
+  conf_data.set('ENT_URANDOM', use_urandom.returncode() == 0)
 endif
 
 configure_file(output : 'config.h',

meson.build

@@ -9,10 +9,13 @@ inc = include_directories('include')
 
 ent_sources = ['ent.c']
 
+ent_dep = declare_dependency(sources : ent_sources,
+                             compile_args : ['-Wall', '-pedantic'],
+                             include_directories : inc)
+
 libent = both_libraries('ent',
-                        ent_sources,
-                        include_directories : inc,
-                        install : true)
+                        dependencies : [ent_dep],
+                        install : false)
 
 pkg_mod = import('pkgconfig')
 pkg_mod.generate(libraries : libent,