From d9b5bf87e724bfbbad78fe254e902048f8d7e534 Mon Sep 17 00:00:00 2001
From: Joseph Coffland <joseph@cauldrondevelopment.com>
Date: Mon, 1 Jun 2020 14:55:52 -0700
Subject: [PATCH 6/7] Fixes and clean up of sizeof test

---
 src/libevent/SConscript | 115 ++++++++++------------------------------
 1 file changed, 28 insertions(+), 87 deletions(-)

diff --git src/libevent/SConscript src/libevent/SConscript
index ab1f72ad..db9884a6 100644
--- src/libevent/SConscript
+++ src/libevent/SConscript
@@ -17,88 +17,25 @@ def CheckSYS_TIMERFD_H(ctx):
 conf.AddTest('CheckSYS_TIMERFD_H', CheckSYS_TIMERFD_H)
 
 
-# sizeof
-# https://github.com/scons/scons/wiki/AutoconfRecipes#ac_check_sizeof
-# Sensible default for common types on common platforms.
-_DEFAULTS_SIZEOF = {
-    'short' : [2],
-    'int' : [4, 2],
-    'long' : [4, 8],
-    'long long' : [8, 4],
-    'unsigned short' : [2],
-    'unsigned int' : [4, 2],
-    'unsigned long' : [4, 8],
-    'unsigned long long' : [8, 4],
-    'float' : [4],
-    'double' : [8],
-    'long double' : [12],
-    'size_t' : [4, 8],
-}
-
-def CheckSizeOf(ctx, type, includes = None):
-    """This check can be used to get the size of a given type,
-    or to check whether the type is of expected size.
-
-    Arguments:
-        - type : str
-            the type to check
-        - includes : sequence
-            list of headers to include in the test code before testing the type
-        Returns:
-                status : int
-                        0 if the check failed, or the found size of the type
-                        if the check succeeded."""
-    minsz = 0
-    maxsz = 16
-
+def CheckSizeOf(ctx, type, defaults, includes = None):
     src = '''
-      #include <sys/types.h>
-      #include <stdlib.h>
-      #include <stdio.h>
-      #include <stdint.h>
+      int main() {
+        int a[1 - 2 * (sizeof(%s) != %d)];
+        return a[0] = 0;
+     }
     '''
-    if includes:
-        src += "\n".join("#include <%s>\n" % i for i in includes)
-
-    ext = '.c'
-    # test code taken from autoconf: this is a pretty clever hack to find that
-    # a type is of a given size using only compilation. This speeds things up
-    # quite a bit compared to straightforward code using TryRun
-    src += r"""
-typedef %s scons_check_type;
-
-int main()
-{
-    static int test_array[1 - 2 * ((long int) sizeof(scons_check_type) > %d)];
-    test_array[0] = 0;
 
-    return 0;
-}
-"""
+    if includes:
+        src = '\n'.join('#include <%s>' % i for i in includes) + '\n' + src
 
-    # Only check if the given size is the right one
     ctx.Message('Checking size of %s ... ' % type)
 
-    # Try sensible defaults first
-    try:
-        szrange = _DEFAULTS_SIZEOF[type]
-    except KeyError:
-        szrange = []
-    szrange.extend(range(minsz, maxsz))
-    st = 0
-
-    # Actual test
-    for sz in szrange:
-        st = ctx.TryCompile(src % (type, sz), ext)
-        if st:
-            break
-
-    if st:
-        ctx.Result('%d' % sz)
-        return sz
-    else:
-        ctx.Result('Failed !')
-        return 0
+    for sz in defaults + range(1, 16):
+        if ctx.TryCompile(src % (type, sz), '.c'):
+            ctx.Result(str(sz))
+            return sz
+
+    raise Exception('Failed to get the sizeof of ' + type)
 
 conf.AddTest('CheckSizeOf', CheckSizeOf)
 
@@ -209,7 +146,17 @@ headers = '''arpa/inet.h fcntl.h ifaddrs.h inttypes.h mach/mach_time.h
 '''
 decls = '''CTL_KERN KERN_ARND KERN_RANDOM RANDOM_UUID'''
 structs = 'addrinfo in6_addr sockaddr_in6 sockaddr_storage'
-sizeof = ['int', 'long', 'long long', 'off_t', 'short', 'size_t', 'void *']
+
+sizeof = [
+    ('short',     [2],    None),
+    ('int',       [4, 2], None),
+    ('long',      [8, 4], None),
+    ('long long', [8, 4], None),
+    ('void *',    [8, 4], None),
+    ('size_t',    [8, 4], ['sys/types.h']),
+    ('off_t',     [8, 4], ['sys/types.h']),
+    ('pthread_t', [8, 4], ['pthread.h']),
+]
 
 gethostbyname_r_3_arg_src = '''
   #ifndef __cplusplus
@@ -284,13 +231,9 @@ def get_event_config_defs():
 
 
     # Sizes
-    for type in sizeof:
-        size = conf.CheckSizeOf(type)
-        if size:
-            defs['SIZEOF_' + to_def(type)] = size
-
-    size = conf.CheckSizeOf('pthread_t', ['pthread.h'])
-    if size: defs['SIZEOF_PTHREAD_T'] = size
+    for type, defaults, includes in sizeof:
+        size = conf.CheckSizeOf(type, defaults, includes)
+        defs['SIZEOF_' + to_def(type)] = size
 
 
     # Decls
@@ -380,13 +323,11 @@ def build_function(target, source, env):
 
     f = open(target, 'w')
 
-    f.write('#ifndef EVENT2_EVENT_CONFIG_H_INCLUDED_\n')
-    f.write('#define EVENT2_EVENT_CONFIG_H_INCLUDED_\n')
+    f.write('#pragma once\n')
 
     for name, value in sorted(defs.items()):
         f.write('#define EVENT__%s %s\n' % (name, value))
 
-    f.write('#endif /* EVENT2_EVENT_CONFIG_H_INCLUDED_ */\n')
     f.close()
 
 
-- 
2.27.0.rc1.5.gae92ac8ae3