call the garbage collector now and then

this enables the assembler to translate larger source files without
running out of memory.

optimized removal of comments.

Author: ThomasWaldmann

esp32_ulp/__main__.py

@@ -1,12 +1,16 @@
 import sys
 
+from .util import garbage_collect
+
 from .assemble import Assembler
 from .link import make_binary
+garbage_collect('after import')
 
 
 def src_to_binary(src):
     assembler = Assembler()
     assembler.assemble(src)
+    garbage_collect('before symbols export')
     addrs_syms = assembler.symbols.export()
     for addr, sym in addrs_syms:
         print('%04d %s' % (addr, sym))

esp32_ulp/assemble.py

@@ -4,6 +4,7 @@
 
 from . import opcodes
 from .nocomment import remove_comments
+from .util import garbage_collect
 
 TEXT, DATA, BSS = 'text', 'data', 'bss'
 
@@ -139,8 +140,7 @@ def parse_line(self, line):
         return label, opcode, args
 
 
-    def parse(self, text):
-        lines = remove_comments(text)
+    def parse(self, lines):
         parsed = [self.parse_line(line) for line in lines]
         return [p for p in parsed if p is not None]
 
@@ -271,10 +271,13 @@ def assembler_pass(self, lines):
                 raise Exception('Unknown opcode or directive: %s' % opcode)
         self.finalize_sections()
 
-    def assemble(self, lines):
+    def assemble(self, text):
+        lines = remove_comments(text)
         self.init(1)  # pass 1 is only to get the symbol table right
         self.assembler_pass(lines)
         self.symbols.set_bases(self.compute_bases())
+        garbage_collect('before pass2')
         self.init(2)  # now we know all symbols and bases, do the real assembler pass, pass 2
         self.assembler_pass(lines)
+        garbage_collect('after pass2')
 

esp32_ulp/util.py

@@ -0,0 +1,11 @@
+DEBUG = False
+
+import gc
+
+
+def garbage_collect(msg, verbose=DEBUG):
+    free_before = gc.mem_free()
+    gc.collect()
+    free_after = gc.mem_free()
+    if verbose:
+        print("%s: %d --gc--> %d bytes free" % (msg, free_before, free_after))

tests/assemble.py

@@ -1,5 +1,6 @@
 from esp32_ulp.assemble import Assembler, TEXT, DATA, BSS, REL, ABS
 from esp32_ulp.assemble import SymbolTable
+from esp32_ulp.nocomment import remove_comments
 
 src = """\
 
@@ -25,7 +26,8 @@ def test_parse_line():
 
 def test_parse():
     a = Assembler()
-    result = a.parse(src)
+    lines = remove_comments(src)
+    result = a.parse(lines)
     assert None not in result