add support for macros such as WRITE_RTC_REG

This is a simplified implementation, rather than adding "proper" support for macros
because we don't need more. The macros WRITE_RTC_REG, READ_RTC_REG, WRITE_RTC_FIELD
and READ_RTC_FIELD are simply expanded in a predefined way. If they are also defined
as macros in the source code, those macros in the source will be ignored.

Author: wnienhaus

esp32_ulp/preprocess.py

@@ -2,6 +2,34 @@
 from .util import split_tokens
 
 
+class RTC_Macros:
+    @staticmethod
+    def READ_RTC_REG(rtc_reg, low_bit, bit_width):
+        return '\treg_rd ' + ', '.join((
+            rtc_reg,
+            '%s + %s - 1' % (low_bit, bit_width),
+            low_bit
+        ))
+
+    @staticmethod
+    def WRITE_RTC_REG(rtc_reg, low_bit, bit_width, value):
+        args = (
+            rtc_reg,
+            '%s + %s - 1' % (low_bit, bit_width),
+            low_bit,
+            value
+        )
+        return '\treg_wr ' + ', '.join(args)
+
+    @staticmethod
+    def READ_RTC_FIELD(rtc_reg, low_bit):
+        return RTC_Macros.READ_RTC_REG(rtc_reg, low_bit, 1)
+
+    @staticmethod
+    def WRITE_RTC_FIELD(rtc_reg, low_bit, value):
+        return RTC_Macros.WRITE_RTC_REG(rtc_reg, low_bit, 1, value + ' & 1')
+
+
 class Preprocessor:
     def __init__(self):
         self._defines = {}
@@ -42,12 +70,34 @@ def expand_defines(self, line):
 
         return line
 
+    def expand_rtc_macros(self, line):
+        clean_line = line.strip()
+        if not clean_line:
+            return line
+
+        macro = clean_line.split('(', 1)
+        if len(macro) != 2:
+            return line
+
+        macro_name, macro_args = macro
+
+        macro_fn = getattr(RTC_Macros, macro_name, None)
+        if macro_fn is None:
+            return line
+
+        macro_args, _ = macro_args.rsplit(')', 1)  # trim away right bracket. safe as comments already stripped
+        macro_args = macro_args.split(',')  # not safe when args contain ',' but we should not have those
+        macro_args = [x.strip() for x in macro_args]
+
+        return macro_fn(*macro_args)
+
     def preprocess(self, content):
         self.parse_defines(content)
         lines = nocomment.remove_comments(content)
         result = []
         for line in lines:
             line = self.expand_defines(line)
+            line = self.expand_rtc_macros(line)
             result.append(line)
         result = "\n".join(result)
         return result

tests/preprocess.py

@@ -169,6 +169,18 @@ def preprocess_should_replace_defines_used_in_defines():
     assert "move r1, (0x1234 << 4)" in p.preprocess(lines)
 
 
+@test
+def test_expand_rtc_macros():
+    p = Preprocessor()
+
+    assert p.expand_rtc_macros("") == ""
+    assert p.expand_rtc_macros("abc") == "abc"
+    assert p.expand_rtc_macros("WRITE_RTC_REG(1, 2, 3, 4)") == "\treg_wr 1, 2 + 3 - 1, 2, 4"
+    assert p.expand_rtc_macros("READ_RTC_REG(1, 2, 3)") == "\treg_rd 1, 2 + 3 - 1, 2"
+    assert p.expand_rtc_macros("WRITE_RTC_FIELD(1, 2, 3)") == "\treg_wr 1, 2 + 1 - 1, 2, 3 & 1"
+    assert p.expand_rtc_macros("READ_RTC_FIELD(1, 2)") == "\treg_rd 1, 2 + 1 - 1, 2"
+
+
 if __name__ == '__main__':
     # run all methods marked with @test
     for t in tests: