refactor: small improvements based on PR comments.

Author: wnienhaus

esp32_ulp/__main__.py

@@ -10,6 +10,7 @@
 
 def src_to_binary(src):
     assembler = Assembler()
+    src = preprocess(src)
     assembler.assemble(src, remove_comments=False)  # comments already removed by preprocessor
     garbage_collect('before symbols export')
     addrs_syms = assembler.symbols.export()
@@ -24,7 +25,6 @@ def main(fn):
     with open(fn) as f:
         src = f.read()
 
-    src = preprocess(src)
     binary = src_to_binary(src)
 
     if fn.endswith('.s') or fn.endswith('.S'):

esp32_ulp/assemble.py

@@ -87,8 +87,8 @@ def set_global(self, symbol):
 
 class Assembler:
 
-    def __init__(self, symbols=None, bases=None, globls=None):
-        self.symbols = SymbolTable(symbols or {}, bases or {}, globls or {})
+    def __init__(self, symbols=None, bases=None, globals=None):
+        self.symbols = SymbolTable(symbols or {}, bases or {}, globals or {})
         opcodes.symbols = self.symbols  # XXX dirty hack
 
     def init(self, a_pass):
@@ -223,7 +223,7 @@ def d_align(self, align=4, fill=None):
             self.fill(self.section, amount, fill)
 
     def d_set(self, symbol, expr):
-        value = int(opcodes.eval_arg(expr))  # TODO: support more than just integers
+        value = int(opcodes.eval_arg(expr))
         self.symbols.set_sym(symbol, ABS, None, value)
 
     def d_global(self, symbol):
@@ -265,6 +265,12 @@ def assembler_pass(self, lines):
                     # machine instruction
                     func = getattr(opcodes, 'i_' + opcode.lower(), None)
                     if func is not None:
+                        # during the first pass, symbols are not all known yet.
+                        # so some expressions may not evaluate to something (yet).
+                        # instruction building requires sane arguments however.
+                        # since all instructions are 4 bytes long, we simply skip
+                        # building instructions during pass 1, and append an "empty
+                        # instruction" to the section to get the right section size.
                         instruction = 0 if self.a_pass == 1 else func(*args)
                         self.append_section(instruction.to_bytes(4, 'little'), TEXT)
                         continue

esp32_ulp/definesdb.py

@@ -19,8 +19,11 @@ def clear(self):
         except OSError:
             pass
 
+    def is_open(self):
+        return self._db is not None
+
     def open(self):
-        if self._db:
+        if self.is_open():
             return
         try:
             self._file = open(DBNAME, 'r+b')
@@ -30,7 +33,7 @@ def open(self):
         self._db_exists = True
 
     def close(self):
-        if not self._db:
+        if not self.is_open():
             return
         self._db.close()
         self._db = None

esp32_ulp/opcodes.py

@@ -307,10 +307,10 @@ def arg_qualify(arg):
         pass
     try:
         entry = symbols.get_sym(arg)
-        return ARG(SYM, entry, arg)
     except KeyError:
-        pass
-    return ARG(IMM, int(eval_arg(arg)), arg)
+        return ARG(IMM, int(eval_arg(arg)), arg)
+    else:
+        return ARG(SYM, entry, arg)
 
 
 def get_reg(arg):

esp32_ulp/preprocess.py

@@ -14,13 +14,12 @@ def READ_RTC_REG(rtc_reg, low_bit, bit_width):
 
     @staticmethod
     def WRITE_RTC_REG(rtc_reg, low_bit, bit_width, value):
-        args = (
+        return '\treg_wr ' + ', '.join((
             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):

esp32_ulp/util.py

@@ -19,14 +19,14 @@ def split_tokens(line):
     tokens = []
     state = NORMAL
     for c in line:
-        if ('a' <= c <= 'z') or ('A' <= c <= 'Z') or ('0' <= c <= '9') or c == '_':
+        if c in "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_":
             if state != NORMAL:
                 if len(buf) > 0:
                     tokens.append(buf)
                     buf = ""
                 state = NORMAL
             buf += c
-        elif c == ' ' or c == '\t':
+        elif c in " \t":
             if state != WHITESPACE:
                 if len(buf) > 0:
                     tokens.append(buf)

tests/compat/expr.S

@@ -1,3 +1,4 @@
+# common example of real world code using expressions
   .set adc_channel, 6
 
   .set adc_oversampling_factor_log, 2
@@ -26,7 +27,13 @@ measure:
   move r3, result
   st r0, r3, 0
 
-  #test that expressions evaluate correctly for all supported operators
+exit:
+  halt
+
+
+# ---
+# test that expressions evaluate correctly for all supported operators
+# (these statements do not mean anything other than testing the operations)
   move r3, 1+2
   move r3, 3-5
   move r3, -5
@@ -39,6 +46,3 @@ measure:
   move r3, 0x1234 & ~2
   move r3, 42|4&0xf  # 46 (4&0xf is evaluated first)
   move r3, (42|4)&0xf  # 14 (42|4 is evaluated first)
-
-exit:
-  halt

tests/fixtures/incl.h

@@ -2,4 +2,4 @@
 #define MACRO(x,y) x+y
 #define MULTI_LINE abc \
                    xyz
-#define CONST2 99
+#define CONST2 99

tests/fixtures/incl2.h

@@ -1,2 +1,2 @@
 #define CONST2 123
-#define CONST3 777
+#define CONST3 777

tests/preprocess.py

@@ -312,6 +312,26 @@ def test_preprocess_should_ensure_no_definesdb_is_created_when_only_reading_from
     assert not file_exists(DBNAME)
 
 
+@test
+def test_preprocess_should_ensure_the_definesdb_is_properly_closed_after_use():
+    content = """\
+    #define CONST 42
+    move r1, CONST"""
+
+    # remove any existing db
+    db = DefinesDB()
+    db.open()
+    assert db.is_open()
+
+    # now preprocess using db
+    p = Preprocessor()
+    p.use_db(db)
+
+    p.preprocess(content)
+
+    assert not db.is_open()
+
+
 if __name__ == '__main__':
     # run all methods marked with @test
     for t in tests: