【question】steps to regenerate configure file

Hi ,


I want to modify some code of gdb, so I have to regenerate the configure file, but I didn't find the relevant documentation, I'm not sure which version of autogen to use? 
This is a bit confusing for newbies like me.
I am going to regenerate the configuration as follows:
```

autogen Makefile.def

autogen Makefile.tpl

aclocal

autoheader

autoconf

./configure

make
```


When I type the command    ```autogen Makefile.def```      the following error will appear,     is my step wrong?






error message:
---------------------------------------------------------------------------------------------------------------
FSM Error:  in state 5 (have_name), event 3 (var_name) is invalid
invalid transition:  in Makefile.def on line 271
token in error:  var_name:  ''flags_to_pass = { flag= LDFLAGS_FOR_BUILD ; };
flags_to_pass = {''


[[...<error-text>]]  = { flag= LDFLAGS_FOR_BUILD ; };
flags_to_pass = {


Likely causes:  a mismatched quote, a value that needs quoting,
or a missing semi-colon
Aborted
--------------------------------------------------------------------------------------------------------------