Merge pull request #231 from zeux/devt-abi

Generate padding fields in VolkDeviceTable to preserve ABI

Author: zeux

generate.py

@@ -7,6 +7,7 @@
 import urllib
 import xml.etree.ElementTree as etree
 import urllib.request
+import zlib
 
 cmdversions = {
 	"vkCmdSetDiscardRectangleEnableEXT": 2,
@@ -157,12 +158,17 @@ def cdepends(key):
 	for key in block_keys:
 		blocks[key] = ''
 
+	devp = {}
+
 	for (group, cmdnames) in command_groups.items():
 		ifdef = '#if ' + group + '\n'
 
 		for key in block_keys:
 			blocks[key] += ifdef
 
+		devt = 0
+		devo = len(blocks['DEVICE_TABLE'])
+
 		for name in sorted(cmdnames):
 			cmd = commands[name]
 			type = cmd.findtext('param[1]/type')
@@ -176,6 +182,7 @@ def cdepends(key):
 				blocks['LOAD_DEVICE'] += '\t' + name + ' = (PFN_' + name + ')load(context, "' + name + '");\n'
 				blocks['DEVICE_TABLE'] += '\tPFN_' + name + ' ' + name + ';\n'
 				blocks['LOAD_DEVICE_TABLE'] += '\ttable->' + name + ' = (PFN_' + name + ')load(context, "' + name + '");\n'
+				devt += 1
 			elif is_descendant_type(types, type, 'VkInstance'):
 				blocks['LOAD_INSTANCE'] += '\t' + name + ' = (PFN_' + name + ')load(context, "' + name + '");\n'
 			elif type != '':
@@ -187,6 +194,14 @@ def cdepends(key):
 		for key in block_keys:
 			if blocks[key].endswith(ifdef):
 				blocks[key] = blocks[key][:-len(ifdef)]
+			elif key == 'DEVICE_TABLE':
+				devh = zlib.crc32(blocks[key][devo:].encode())
+				assert(devh not in devp)
+				devp[devh] = True
+
+				blocks[key] += '#else\n'
+				blocks[key] += f'\tPFN_vkVoidFunction padding_{devh:x}[{devt}];\n'
+				blocks[key] += '#endif /* ' + group + ' */\n'
 			else:
 				blocks[key] += '#endif /* ' + group + ' */\n'
 

volk.c

@@ -21,6 +21,8 @@
 #	include <stdlib.h>
 #endif
 
+#include <string.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -188,6 +190,7 @@ VkDevice volkGetLoadedDevice(void)
 
 void volkLoadDeviceTable(struct VolkDeviceTable* table, VkDevice device)
 {
+	memset(table, 0, sizeof(*table));
 	volkGenLoadDeviceTable(table, device, vkGetDeviceProcAddrStub);
 }