update Go generator (riscv#124)

parse.py

@@ -838,8 +838,11 @@ def make_c(instr_dict):
     enc_file.close()
 
 def make_go(instr_dict):
-    prelude = '''// Code generated by parse_opcodes -go; DO NOT EDIT.
 
+    args = " ".join(sys.argv)
+    prelude = f'''// Code generated by {args}; DO NOT EDIT.'''
+
+    prelude += '''
 package riscv
 
 import "cmd/internal/obj"
@@ -855,10 +858,12 @@ def make_go(instr_dict):
 func encode(a obj.As) *inst {
 	switch a {
 '''
+
     endoffile = '''  }
 	return nil
 }
 '''
+
     instr_str = ''
     for i in instr_dict:
         enc_match = int(instr_dict[i]['match'],0)
@@ -876,6 +881,12 @@ def make_go(instr_dict):
         file.write(instr_str)
         file.write(endoffile)
 
+    try:
+        import subprocess
+        subprocess.run(["go", "fmt", "inst.go"])
+    except:
+        pass
+
 def signed(value, width):
   if 0 <= value < (1<<(width-1)):
     return value
@@ -891,7 +902,12 @@ def signed(value, width):
         if i in extensions:
             extensions.remove(i)
     print(f'Extensions selected : {extensions}')
-    instr_dict = create_inst_dict(extensions)
+
+    include_pseudo = False
+    if "-go" in sys.argv[1:]:
+        include_pseudo = True
+
+    instr_dict = create_inst_dict(extensions, include_pseudo)
     with open('instr_dict.yaml', 'w') as outfile:
         yaml.dump(instr_dict, outfile, default_flow_style=False)
     instr_dict = collections.OrderedDict(sorted(instr_dict.items()))