Add a dependency scanner for gas/yasm and nasm (incomplete)

waflib/Tools/asm.py

@@ -34,9 +34,22 @@ Support for pure asm programs and libraries should also work::
 			target = 'asmtest')
 """
 
-from waflib import Task
+import re
+from waflib import Errors, Logs, Task
 from waflib.Tools.ccroot import link_task, stlink_task
 from waflib.TaskGen import extension
+from waflib.Tools import c_preproc
+
+re_lines = re.compile(
+	'^[ \t]*(?:%)[ \t]*(ifdef|ifndef|if|else|elif|endif|include|import|define|undef)[ \t]*(.*)\r*$',
+	re.IGNORECASE | re.MULTILINE)
+
+class asm_parser(c_preproc.c_parser):
+	def filter_comments(self, node):
+		code = node.read()
+		code = c_preproc.re_nl.sub('', code)
+		code = c_preproc.re_cpp.sub(c_preproc.repl, code)
+		return re_lines.findall(code)
 
 class asm(Task.Task):
 	"""
@@ -45,6 +58,28 @@ class asm(Task.Task):
 	color = 'BLUE'
 	run_str = '${AS} ${ASFLAGS} ${ASMPATH_ST:INCPATHS} ${DEFINES_ST:DEFINES} ${AS_SRC_F}${SRC} ${AS_TGT_F}${TGT}'
 
+	def scan(self):
+		if self.env.ASM_NAME == 'gas':
+			return c_preproc.scan(self)
+			Logs.warn('There is no dependency scanner for Nasm!')
+			return  [[], []]
+		elif self.env.ASM_NAME == 'nasm':
+			Logs.warn('The Nasm dependency scanner is incomplete!')
+
+		try:
+			incn = self.generator.includes_nodes
+		except AttributeError:
+			raise Errors.WafError('%r is missing the "asm" feature' % self.generator)
+
+		if c_preproc.go_absolute:
+			nodepaths = incn
+		else:
+			nodepaths = [x for x in incn if x.is_child_of(x.ctx.srcnode) or x.is_child_of(x.ctx.bldnode)]
+
+		tmp = asm_parser(nodepaths)
+		tmp.start(self.inputs[0], self.env)
+		return (tmp.nodes, tmp.names)
+
 @extension('.s', '.S', '.asm', '.ASM', '.spp', '.SPP')
 def asm_hook(self, node):
 	"""

waflib/Tools/gas.py

@@ -16,3 +16,4 @@ def configure(conf):
 	conf.env.ASLNK_TGT_F = ['-o']
 	conf.find_ar()
 	conf.load('asm')
+	conf.env.ASM_NAME = 'gas'

waflib/Tools/nasm.py

@@ -24,3 +24,8 @@ def configure(conf):
 	conf.env.ASLNK_TGT_F = ['-o']
 	conf.load('asm')
 	conf.env.ASMPATH_ST = '-I%s' + os.sep
+	txt = conf.cmd_and_log(conf.env.AS + ['--version'])
+	if 'yasm' in txt.lower():
+		conf.env.ASM_NAME = 'yasm'
+	else:
+		conf.env.ASM_NAME = 'nasm'