handle empty defines when pasting tokens

tests/preproc/wscript

@@ -142,6 +142,21 @@ def build(bld):
 		'e' : 'e a || b || c || d'
 	}
 
+
+	def test_pasting():
+		main = bld.path.find_resource('src/pasting.c')
+		defs = ['PREFIX_VAL=', 'SUFFIX_VAL=']
+		bld.env['DEFINES'] = ["%s %s" %(x[0], trimquotes('='.join(x[1:]))) for x in [y.split('=') for y in defs]]
+		gruik = c_preproc.c_parser([main.parent])
+		gruik.start(main, bld.env)
+		if len(gruik.nodes) == 1 and gruik.nodes[0].name == 'a.h':
+			color = "GREEN"
+		else:
+			color = "RED"
+		pprint(color, "token pasting -> %r (expected a.h)" % gruik.nodes)
+
+	test_pasting()
+
 	def test(x, result):
 		toks = c_preproc.tokenize(x)
 		c_preproc.reduce_tokens(toks, defs, [])
@@ -156,6 +171,7 @@ def build(bld):
 	test('a&&b&&c&&d', 0)
 	test('e', 1)
 
+
 	return
 	test("1?1,(0?5:9):3,4", 0) # <- invalid expression
 

waflib/Tools/c_preproc.py

@@ -478,7 +478,7 @@ def reduce_tokens(lst, defs, ban=[]):
 							if one_param: args.append(one_param)
 							break
 						elif v2 == ',':
-							if not one_param: raise PreprocError("empty param in funcall %s" % p)
+							if not one_param: raise PreprocError("empty param in funcall %s" % v)
 							args.append(one_param)
 							one_param = []
 						else:
@@ -645,7 +645,11 @@ def extract_macro(txt):
 		return (name, [params, t[i+1:]])
 	else:
 		(p, v) = t[0]
+		if len(t) > 1:
 			return (v, [[], t[1:]])
+		else:
+			# empty define, assign an empty token
+			return (v, [[], [('T','')]])
 
 re_include = re.compile('^\s*(<(?P<a>.*)>|"(?P<b>.*)")')
 def extract_include(txt, defs):